NBSIR

87-3079

Reference

Center for Chemical Engineering

Technical Activities

N

Fiscal Year 1987

PUBLICATIONS

-

I Allies 51M33b

February 1988

National Engineering Laboratory

itionai Bureau of Standards

I.S. Department of Commerce

Boulder, Colorado 80303

NBSIR

87-3079

Center for Chemical Engineering

Technical Activities

Fiscal Year 1987

•Research Informati<

•National bureau of

J. Hord, Editor Gaithersburg, .Mary Land

cr

B99

February 1988

Prepared for:

National Research Council (NRC)

Board on Assessment of NBS Programs

February 24-25, 1988

Gaithersburg, Maryland 20899

John W. Lyons, Director

National Engineering Laboratory

Jesse Hord, Director

Center for Chemical Engineering

r

*

U.S. DEPARTMENT OF COMMERCE, C. William Vc-r \ V

•

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Direct '

CENTER FOR CHEMICAL ENGINEERING

EVALUATION PANEL MEMBERS

Mr. Melvin A. Albright

Phillips Petroleum Company, Retired

Route 3 , Box 403AA

Bartlesville, OK 74003

Prof. James E. Bailey

Dept, of Chemical Engineering

California Institute of Technology

Pasadena, CA 91125

Dr. Beverly J. Berger

Assistant Director for Life Science

Office of Science & Technology Policy

Executive Office Bldg., Room 5026

Washington, DC 20506

Prof. Stuart W. Churchill

The Carl V.S. Patterson

Professor of Chemical Engineering

University of Pennsylvania

311A Towne Building

220 South 33rd Street

Philadelphia, PA 19104

Prof. Edward L. Cussler

Chemical Engineering and

Materials Science Department

University of Minnesota

421 Washington Avenue, S.E.

Minneapolis, MN 55455

Dr. Robert R. Dorsch

Manager of Biotechnology Development

Medical Products Department

Experimental Station

E.I. du Pont de Nemours and Company

E400/2418

Wilmington, DE 19898

Dr. Walter E. Goldstein

Vice President and

Director of R&D

Escagen Corp

.

830 Bransten Road

San Carlos, CA 94070

Dr. Douglas E. Leng

Research Scientist and

Laboratory Director

Central Research

Engineering Research Laboratory

Dow Chemical Company

M.E. Pruitt Building

Midland, MI 48674

Prof. John P. O'Connell

Dept, of Chemical Engineering

University of Florida

Gainesville, FL 32611

Prof. William R. Schowalter*

Class of 1950 Professor of

Engineering and Applied Science

Dept, of Chemical Engineering

Princeton University

Princeton, NJ 08544

Dr. Charles D. Scott

Senior Corporate Fellow

Chemical Technology Division

Martin Marietta Energy Systems, Iir Oak Ridge National Laboratory

P.0. Box X

Oak Ridge, TN 37831-6226

Dr. Albert S. Tenney, III

Market Manager

Leeds and Northrup Company

Sumneytown Pike

North Wales, PA 19454

*CHAIRMAN

- iii-
Technical research activities performed by the Center

for Chemical Engineering during the Fiscal Year 1987 are summarized herein. These activities fall within

the general categories of process measurement,

thermophysical properties data, and chemical

engineering science. They embody: development and

improvement of measurement principles, measurement

standards, and calibration services such as volumetric

and mass flow rates, liquid volume, liquid density, and

humidity; generation (via accurate measurements and

advanced predictive models) of reliable reference data

for thermophysical properties of pure fluids, fluid

mixtures, and solids of vital interest to industry; and

development of improved correlations, models, and

measurement techniques for complex flows, heat and mass

transport, mixing, and chemically reacting flows of

interest in modern unit operations.

INTRODUCTION

This document summarizes technical research activities of the Center

for Chemical Engineering (CCE) during Fiscal Year 1987 (October 1, 1986

through September 30, 1987). This Center is one of six such units that

compose the National Engineering Laboratory of the National Bureau of

Standards. A brief summary of the structure and technical activities of the

National Bureau of Standards is given in the introductory portion of this

report, along with organizational information on the Center for Chemical

Engineering

.

The activities of the Center are focused on chemical engineering in

support of the chemical and related industries (including chemical,

petrochemical, biochemical, petroleum, gas, energy, food and drug, paper,

etc.). The goal of the Center is to provide the fundamental scientific

framework for reliable measurement and data bases that assure equity in

domestic and international trade, and enable innovation as well as improved

design and control of chemical processes. The Center's research contributes

significantly to the ability of U.S. industry to compete in world markets.

This summary report is presented in three sections, one for each

participating division in the Center: Chemical Engineering Science,

Thermophysics, and Chemical Process Metrology. Each division summary is

related in the same format but with individual style and emphasis. These

summaries lead off with an introduction; state the division goal; outline

division subelement (group) functions; summarize project activities; cite

primary publications; and close with lists of conferences and workshops

hosted, sponsored, or organized by the division or Center.

If additional information is desired on any technical project reported

herein, readers should address their inquiries to the appropriately

identified project staff via the Center for Chemical Engineering, National

Bureau of Standards, 325 Broadway, Boulder, CO 80303.

-IV-
CONTENTS

Page

LIST OF PANEL MEMBERS iii

INTRODUCTION iv

ORGANIZATION OF THE NATIONAL BUREAU OF STANDARDS vi

ORGANIZATION OF THE CENTER FOR CHEMICAL ENGINEERING vii

MISSION OF THE NATIONAL BUREAU OF STANDARDS viii

TECHNICAL ACTIVITIES OF THE

CHEMICAL ENGINEERING SCIENCE DIVISION

1. Introduction

2. Goal 2

3 . Group Functions

4. Selected Project Summaries 4

5. Publications 10

6. Conferences 15

TECHNICAL ACTIVITIES OF THE

THERMOPHYSICS DIVISION

1. Introduction 16

2. Goal 17

3 . Group and Program Functions 17

4. Selected Project Summaries 18

5. Publications 3 5 6. Conferences and Workshops 41

TECHNICAL ACTIVITIES OF THE

CHEMICAL PROCESS METROLOGY DIVISION

1. Introduction 4 2 2. Goal 44

3 . Group Functions 44

4. Selected Project Summaries

5 . Publications 6 5 6. Conferences and Workshops 70

-v-
ORGANIZATION OF THE NATIONAL BUREAU OF STANDARDS

| NATIONAL ENGINEERING!

1 LABORATORY I

o Applied Mathematics

o Electronics & Electrical

Engineering

o Manufacturing Engr ’ g

o Building Technology

o Fire Research

o Chemical Engineering

o Denotes Center

* Denotes Division

| NATIONAL BUREAU|

I OF STANDARDS I

| INSTITUTE FOR COMPUTER!

I SCIENCES & TECHNOLOGY!

* Information Systems

Engineering

* Systems and Software

Technology

* Computer Security

* Systems and Network

Architecture

* Advanced Systems

| INSTITUTE FOR MATERIALS!

I SCIENCE & ENGINEERING I

* Ceramics

* Fracture & Deformation

* Polymers

* Metallurgy

* Reactor Radiation

| NATIONAL MEASUREMENT!

LABORATORY |

o Basic Standards

o Radiation Research

o Chemical Physics

o Analytical Chemistry

-VI-
ORGANIZATION OF THE CENTER FOR CHEMICAL ENGINEERING

CENTER FOR CHEMICAL ENGINEERING

*J. Hord, Director

H. Semerjian, Act. Deputy Director

J. Ulbrecht, Senior Consultant

Optical Diagnostics Group

A. Macek. Acting Group Leader

| ‘CHEMICAL ENGINEERING SCIENCE DIVISION| | THERMOPHYSICS DIVISION |

| CHEMICAL PROCESS METROLOGY DIVISION

J V, Schrodt . Chief |_ I *N. Olien. Chief L J H. Semerjian, Chief

1

1

1 Transport Processes

1

1

| - Equation of State & Fluid Flow

1 (S. Sikdar) Statistical Physics (G. Mattingly)

1

1 System Dynamics

(R. Kayser)

Multiphase Reacting Flow

1 (J. Brennan) | - ‘Properties of Fluids (A. Gaigalas)

1 Properties of Solids

(W. Haynes)

1 High Temperature Reacting

1 (L. Sparks) Flow

1

1

1

1

‘Located in Boulder

| - Dynamic Measurements

(A. Cezairliyan)

1

(A. Macek)

Process Sensing

(K. Kreider)

vii-
MISSION OF THE

NATIONAL BUREAU OF STANDARDS (NBS)

The basic mission of the National Bureau of Standards is to provide for

the Nation's measurements and standards needs. NBS applies its expertise in

science and engineering to foster the attainment of such national goals as: economic growth through innovation and productivity growth in industry and

commerce, and through optimal utilization of labor, energy and material

resources; reasonable and equitable regulatory decision-making with maximum

benefit and minimum economic impact and uncertainty; equity in U.S.

commerce through mutual understanding and acceptance of recognized transfer

standards; and accuracy and compatibility in scientific communications and

technology transfer among industry, government and academia, including the

ability to make meaningful comparisons between the theoretical predictions

and empirical data used in developing scientific knowledge.

Through performance of the functions set forth in the NBS Organic Act

of 1901 and subsequent revisions, and through numerous other statutes, the

Bureau pursues its mission by fulfilling three major roles. The Bureau of

Standards: (1) is the Nation's central reference laboratory and lead agency

for the development and provision of measurement standards, measurement

methods and techniques, and standard reference materials and data essential

for the resolution of Federal, State, and local scientific and technical

measurement issues; (2) addresses technological problems for the Nation

through the application of basic physical, chemical, mathematical, and

engineering science by providing traceability of measurements to national

standards essential for ensuring measurement comparability, by uniform

determination of the physical, chemical, and engineering properties of

matter, and by provision of uniform methods for measuring the performance of

materials, products, and engineered systems products; and (3) enhances the

technological and scientific base of the Nation's productive sectors by

developing basic technologies and information that underlie product and

process development and innovation.

As a major operational unit of the Department of Commerce, NBS also

contributes significantly to fulfilling the Department's mission to promote

trade and commerce and to ensure the smooth and orderly working of our economy

NATIONAL MEASUREMENT LABORATORY: Provides the national system of physical

and chemical measurement; coordinates the system with measurement systems of

other nations and furnishes essential services leading to accurate and

uniform physical and chemical measurement throughout the Nation's scientific

community, industry, and commerce; provides advisory and research services

to other Government agencies; conducts physical and chemical research;

develops, produces, and distributes standard reference materials; provides

standard reference data; provides calibration services; and collaborates

with the Bureau's major organizational units in carrying out its

responsibilities

-viii-
INSTITUTE FOR COMPUTER SCIENCES AND TECHNOLOGY: Provides scientific and

technical services to the central management agencies (e.g., the Office of

Management and Budget and the General Services Administration) to support the

formulation of Federal automatic data processing (ADP) policies, the

selection and direction of Federally sponsored computer research and

development, and the resolution of policy issues affecting computer use;

develop and recommend Federal Information Processing Standards; participate

in the development of voluntary industry ADP standards in both national and

international organizations; conduct research in the science and

technologies of automatic data processing, computers, and networks; provide

direct technical assistance to other Federal agencies in solving specific

computer applications problems; cooperate with private sector users in

determining standards requirements; cooperate with users in industry to

test standards and develop certification techniques; conduct information

exchange activities in the areas of computer and networking technologies;

provide technical leadership for the development of national and

international standards for ADP products to enhance the international trade

position of the U.S. computer industry and to ensure that international

standards do not form trade barriers; cooperate with representatives of

foreign governments and organizations in research and testing activities; and

monitor Federal Government participation in voluntary commercial standards

development efforts.

INSTITUTE FOR MATERIALS SCIENCE AND ENGINEERING: Develops and maintains the

scientific competences and experimental facilities necessary to provide the

Nation with a central basis for uniform physical measurements, measurement

methodology, and measurement services fundamental to the processing,

characterization, properties and performance of materials, and to other

essential areas in materials science; provides government, industry,

universities, and consumers with standards, measurement methods, data, and

quantitative understanding concerning metals, polymers, ceramics,

composites, and glasses; characterizes the structure of materials, chemical

reactions, and physical properties which lead to the safest, most efficient

uses of materials, improve materials technologies, provide the bases for

advanced material technologies in basic and high-technology industries, and

encourage recycling; obtains accurate experimental data on behavior and

properties of materials under service conditions to assure effective use of raw and manufactured materials , provides technical information such as reference data, materials measurement methods, and standards to processors,

designers, and users for selection of cost-effective combinations of

materials, processes, designs, and service conditions; uses the unique NBS

reactor facilities to develop neutron measurement methodology, develop

sophisticated structure characterization techniques, reference data, and

standards; participates in collaborative efforts with other NBS

organizational units in the interdisciplinary developments in materials

science; and disseminates generic technical information from the Divisim

to private and public sector scientific organizations through special

cooperative institutional arrangements and through conventional distrihut ; > mechanisms

-IX-
NATIONAL ENGINEERING LABORATORY: Provides technology ahd technical

services to users in the public and private sectors to address national

needs and to solve national problems in the public interest; conducts

research in engineering and applied science in support of objectives in

these efforts; builds and maintains competence in the necessary disciplines

required to carry out this research and technical service; develops

engineering data and measurement capabilities; provides engineering

measurement traceability services; develops test methods and proposes

engineering standards and code changes; develops and proposes new engineering practices; develops and improves mechanisms to transfer

results of its research to the ultimate user; develops and demonstrates

new institutional practices to stimulate use of technology; and collaborates

with the National Measurement Laboratory in conducting its assigned

responsibilities

CENTER FOR CHEMICAL ENGINEERING: Performs research in process metrology,

thermophysical properties of fluids and solids, and unit operations and

processes; provides measurement practices and standards, fundamental

engineering data, calibration and measurement services, and engineering

science for the chemical and related industries, academe, and Government.

CHEMICAL ENGINEERING SCIENCE DIVISION: Develops and maintains

competence to provide essential engineering measurement and data bases

that underlie the design and performance of chemical engineering

processes and the behavior of solid materials of importance to the

chemical and related industries; performs basic and applied research in

unit operations (heat and mass transfer, and separations including

membranes, chemical complexation , crystallization, selective

adsorption, and liquid- liquid extraction), systems engineering,

thermodynamic analyses of subprocesses, and scale-up; performs thermal

and related properties measurements research to develop data-predictive

models and reference materials for solid feedstocks and fuels (coal and

gas hydrates) and for technical solids (insulating materials, metals,

alloys, polymers, composites, and ceramics); provides critically

evaluated data, measurement standards, predictive models, and

engineering correlations in these research activities.

THERMOPHYSICS DIVISION: Develops new measurement techniques,

thermodynamic models, and molecular theories to describe the

thermophysical behavior of condensed matter ranging from classical

fluids and solids to highly complex fluid mixtures containing molecules

of varying size, polarity, and chemical nature. Research includes

multicomponent-multiphase fluid mixtures, interfacial phase

transitions, nucleation, computer simulation of fluid behavior,

critical point phenomena and properties, properties of supercritical

fluids, phase separation, equations of state, and transport processes

in fluids and high-melting temperature metals. Results include:

theoretically-based predictive models and correlations that use transportable computer codes to predict thermophysical properties of

condensed substances; state-of-the-art experimental measurements; and

critically evaluated properties data.

-x-
CHEMICAL PROCESS METROLOGY DIVISION: Develops improved measurement

techniques, theoretical and computational models to describe and

qualify the performance of laboratory and process plant instruments,

and complementary advanced fluid dynamics analyses/models to explain

the behavior of fundamental fluid flows; develops experimental and

theoretical means to characterize fluid behavior (solid- fluid slurry

flow modes, fluidized beds, chemically reacting flows, etc.) and to

evaluate the performance of combusting flows (gaseous, liquid, solid

and slurry fuels) with emphasis on high temperature, corrosive and

erosive exhaust streams; develops measurement standards and provides

measurement services for flow (volume and mass rates), fluid density,

fluid volume, and humidity; and provides advanced measurement

techniques, standard measurement practices, and technical data

(experimental, theory and computer models) for measurement, analysis

and control of chemical processes.

-xi-

TECHNICAL ACTIVITIES

OF THE

CHEMICAL ENGINEERING SCIENCE DIVISION

V.N. Schrodt, Chief

1. INTRODUCTION

Efficient design and operation of plants and facilities in the chemical,

biochemical, petrochemical, petroleum, gas and other processing industries

are strongly dependent on reliable engineering data and well - documented

characterization of process mechanisms. Efficient design and operation

enable U.S. industry to compete more effectively in the world marketplace,

where intense international competition has focused efforts to improve

manufacturing equipment and processes. Furthermore, an increased emphasis on environmental protection has created a need for alternative processes

operating with closer tolerances, emphasizing higher yields and internal

recycling with separation, so that fewer pollutants are produced. The

development of accurate process models, for the design of the newer and less

conventional plants and to improve conventional ones, requires reliable and

well -documented process characteristics as well as accurate models for the

transport operations and dynamics represented within these industrial

processes. The work of the Chemical Engineering Science Division is focused

on providing the knowledge and understanding needed for the elemental

processes, and on advancing the state of the art for transport phenomena

models and theory. The key ingredients are: laboratory determination of

elemental process mechanisms and characteristics, theoretically based

predictive models for subprocesses involving and using complex fluids and

solids, and analysis of the dynamics of engineering systems. In addition

contributions related to process design and operation, the work of the

Division is involved in measurements and data necessary for accurate and

verifiable custody transfer of chemicals and fuels.

In specific areas that relate to the research of the other CCE

Divisions, close collaborative interactions have been developed. There i strong collaboration with the Thermophysics Division to integrate fluid • solids properties with process mechanisms and models, and with the Chemic tl Process Metrology Division in flow research. These collaborations includseveral joint projects sponsored by other agencies, and new ones are b< i: explored.

One of the primary research efforts of the Division is focused on industries related to the new biotechnology. For the most part, a the'

and quantitative understanding of the behavior of separation factors ,u ! transport mechanisms of these new biochemical systems does not prora-p.’

exist, especially as these relate to products created by genetic engin*-- r The complexity of the phenomena involved, and the vast array of pi <>.! .,

•

; processes encountered, preclude the possibility of a purely expo r i i: • •: correlative approach. The approach must be one which include • theory, and evaluation so as to yield accurate process and re la ted :

1
phenomena, and which facilitates the development of generic predictive models

that are applicable to a broad range of biosubstances. The theoretical

effort will break new ground in understanding separations at the molecular

level, phase equilibria involving multiple phases, biological system

behavior, heat and mass transfer, and other unit operations. Experimental

efforts include membrane separations of amino acids and two -phase aqueous

extraction. Other extensions of the state of the art in separation

technology are anticipated in the Division's long range plans.

The research of the Division addresses scientific issues of national

interest in which NBS expertise and its impartial position are critical to an acceptable resolution, as with the highly accurate measurement and modeling

of the flow of fluids such as natural gas, selected fluid mixtures, and

cryogens. Standard Reference Materials are developed for selected thermal

properties of certain solid materials of interest to the chemical and related

industries. The majority of the effort is directed toward problems of the

future. These include, but are not restricted to: 1) transport processes

related to the efficient use of gases and liquids such as natural and

synthesis gas, methanol, etc., for use as chemical feedstocks and fuels;

2) use of more selective separation processes; 3) bioproduct

separation/purification technology needed for large scale manufacture of

biochemicals; and 4) new techniques for management and disposal of

potentially harmful chemical wastes. The strategy is to perform basic

research, generic to the science underlying the chemical, biochemical and

petrochemical processing industries, which requires the special role of NBS

as an impartial national laboratory excelling in measurements and their

interpretation. During the past year, the effort in two-phase aqueous

extraction research has been expanded to include a project on bioseparations

using new polymers and affinity ligands. Work was continued on heat transfer

in supercritical extraction processes and on the use of reaction systems at

supercritical conditions to treat hazardous wastes. A new project has been

funded, initiating research on flow through porous beds. An effort to

involve the Division in research related to Computer Integrated Processing is

being considered.

In addition, the Chemical Engineering Science Division serves other

government agencies, trade associations, etc., by providing research

appropriate to the mission of the National Bureau of Standards and

consistent with the goals of the Center for Chemical Engineering and the

Division. This externally supported research constitutes a major part of the

planned effort in achieving the goals of the Division.

2. GOAL

The goal of the Division is to provide evaluated generic engineering

design data and elemental process engineering models; standard measurement

procedures and test methods; predictive techniques, correlations, computer

codes , and underlying theories needed by the chemical and related industries

to design, control, and develop new manufacturing processes.

The output of this program assists these industries in maintaining and

enhancing their competitiveness in the international marketplace. The

2
primary means of accomplishing this goal is by providing theoretically based

modeling and predictive techniques, state-of-the-art measurement techniques,

and advanced understanding of elemental process mechanisms . The approach is

to conduct research on fundamental concepts, new ideas and phenomena, and

predictive models in synergism with experimental programs. These efforts

nurture development of new processing techniques, provide accurate models of

transport phenomena, and lead to understanding of advanced engineering

concepts. An essential corollary of these efforts is the critical evaluation

and correlation of experimental measurement techniques , leading to the

development of voluntary standard measurement practices and test methods

3. GROUP FUNCTIONS

The research of the Division is organized into three technical groups:

Transport Processes, System Dynamics, and Properties of Solids.

o Transport Processes - S.K. Sikdar, Group Leader

The Transport Processes Group performs experimental, theoretical, and

mathematical modeling research in: membrane processes; separation of gases,

and biochemicals; heat transfer; reactor design; and transport processes in

microgravity

o System Dynamics - J.A. Brennan, Group Leader

The System Dynamics Group performs research to provide data, measurement

methodology, and thermodynamic criteria for the optimum application of

fundamental principles in physical process operations -- including flow

metrology at normal and extreme conditions, fluid management in normal and

low gravity, and mass and energy changes in multicomponent, multiphase

systems --to support programs of other agencies and industrial trade

organizations and to promote efficiency and measurement accuracy in the

chemical and allied industries.

o Properties of Solids - L.L. Sparks, Group Leader

The experimental and analytical research of the Properties of Solids

Group is focused on the thermal properties (thermal conductivity, thermal

expansion, and heat capacity) of industrially important solids such as: ceramics, composites, polymers, foams, fibers, f iberboards , aggregates,

metals, and solid fuels (e.g. coal, oil shale, and gas hydrates). Work is

performed on the ignition and combustion characteristics and rapid oxidat in:

of metal alloys, in an oxygen environment, at pressures up to 20 MPa.

Efficiencies and new concepts of refrigeration are studied.

3
4. SELECTED PROJECT SUMMARIES

TRANSPORT PROCESSES GROUP

Separation by Reversible Chemical Complexation:

Data. Mechanisms and Modeling

R.D. Noble, J.J. Pellegrino, R.D. Nassimbene,

D. Randolph, M.-F. Jin, S.K. Sikdar

Reversible chemical complexation offers important advantages over conventional methods for separating species from gases and liquids. The

objectives of this research are to develop basic measurement techniques and

standards, provide a body of high quality experimental data, and develop

predictive models and computer codes for the use of this facilitated

transport technique in separation processes. The fundamental characteristics

of this separation technique are being studied by performing experimental

work on two applications: 1) selective separation of gases by an immobilized

liquid membrane consisting of an ion exchange membrane neutralized by an organic base carrier, and 2) selective separation of carboxylic and amino

acids by acid and salt-forms of ion exchange membranes.

The experimental part of the program includes measurement of mass transfer fluxes and determination of the mechanisms of transport. Mathematical

modeling is employed to develop equations to predict species fluxes and

separation factors of one species over another. Gases which have been

successfully separated using ethylene diamine-mediated perfluorinated ion

exchange membranes are CO2 and H2 S. Current efforts are being directed

toward hydrogen. In liquids, transport data are being collected on some carboxylic and amino acids, and the mechanism of transport is being

established. The gas separation work is funded by DoE.

Biochemical Separation

B.R. Bateman, D. Szlag, K. Giuliano, R.A. Perkins,

M. Scurry, D. Steward, H. Cabezas , B. Dale, S.K. Sikdar

The major objective of the biochemical separation program is to provide

data and understanding necessary for the design of industrial bioseparation

processes. Current research activities are focused on the technique of twophase aqueous extraction as a means of separating proteins from aqueous

solutions

Aqueous two -phase extraction has the potential of being a dominant

factor in the downstream processing of bioproducts. Used in the early part

of a multi-step multi- technique bioseparation train, this technique can greatly concentrate proteins. However, the cost of dextran, a constituent of

the polyethylene glycol (PEG) -dextran two-polymer system used in this

technique, remains an impediment to the commercial exploitation of the two4
phase aqueous extraction method. Finding an inexpensive substitute for

dextran, and characterizing the phase and protein partition behavior is an important goal of this research.

The PEG-maltodextrin system has been identified as a promising low cost

two -phase system with significant advantages over the conventional PEGdextran system. Apart from the cost advantage of maltodextrins (less than 1%

of the cost of dextran) , the low viscosity of the maltodextrin phase greatly

speeds phase disengagement without the use of centrifugation. Protein

partition and the separation factor of the desired protein can be greatly

enhanced by attaching common textile dye ligands to PEG. The dye ligand- PEGmaltodextrin system has been demonstrated to work efficiently for model

proteins such as bovine serum albumin and alcohol dehydrogenase, as well as on cell lysates. We have collected protein partition coefficient and phase

diagram data on the PEG-maltodextrin system. Comparable data sets on the

conventional PEG-dextran systems have also been collected.

On the theoretical side, a statistical thermodynamic approach is being

investigated as a tool to predict protein partition coefficients. In the

fist phase of this activity, the technique of direct correlation function

integrals (DCFI) has been successfully applied to accurately predict phase

diagrams of the PEG-water- salt system. Future activity will include the

study of dye- ligand partition and protein partition in the PEG-maltodextrin

systems. The bioseparation program is collaborative with the University of

Arizona and the University of Bombay.

In a related study on the thermodynamics of protein unfolding, we have

found that the enthalpy and heat capacity changes on protein denaturation

correlated quite well with the transfer free energies of the constituent

amino acids, regardless of the sequence. Thus it has been found possible to

predict the free energy of denaturation from literature data on transfer f . • • energy of amino acids.

Plans are in place to initiate research in other areas of bioseparat iot.

such as affinity membrane, affinity chromatography and electrophoresis.

Heat and Mass Transfer to Supercritical Fluid Mixtures

M.C. Jones, P.J. Giarratano, L.A. Powers, S.M. Selim

In this project, transport rates are investigated for supercritical , and liquid mixtures in the region of the solution critical point and, in

particular, the retrograde condensation region. This condensation pmc<

of industrial importance for supercritical extraction as one means of

separating solvent from extract. Despite the fact that the thermodvn..::

the process are well known, very little has been done on the study of

transport rates. The approach is to apply fundamental principles of

transport mechanisms to precise measurements made on mixtures with v.l!

documented thermophysical properties.

5
To date, measurements have been made on the n- decane -carbon dioxide

system at two pressures and five compositions in the region of the critical

solution locus. Heat transfer rates have been obtained for a heated

horizontal cylinder with crossflow and under natural convection conditions.

Several facts have been established. First, heat transfer rates in crossflow

are indistinguishable from those in natural convection when the wall

temperature rise is above about 10 K. This is expected on the basis of the

high Rayleigh number achievable in natural convection for supercritical

fluids. Second, it has been established that heat transfer rates on the

condensation side of the critical locus are larger than on the evaporation

side and, further, that the condensation heat transfer rates are a factor of

two greater than can be accounted for by classical film condensation theory

using the best available estimates of mixture properties. Finally, at high

condensation heat transfer rates, wall temperatures become unstable in a region where multiple steady states have been observed.

The variation in the interfacial tension along the phase boundary may be

responsible for some of these results and future experiments are planned to

make direct visual observations of the phase change mechanisms. Future work

is also planned to extend the observations to other solutes and geometries

and to construct a mathematical framework for the correlation of experimental

results

SYSTEMS DYNAMICS GROUP

Superfluid Helium Transport in Zero Gravity

D . E . Daney , P . R . Ludtke

Transferring cryogens in space is an integral part of NASA's space

program. For cooling and maintenance of expensive equipment in space,

superfluid helium needs to be transferred in a microgravity environment. The

NBS approach is to use a centrifugal pump, free of cavitation problems. The

objective of this program is to support the NASA mission by providing a data

base on superfluid helium pumping characteristics, and to aid in the

fabrication of a prototype pump for tests onboard a space shuttle.

Metering of Natural Gas and Cryogenic Liquids

J.A. Brennan, S.E. McFaddin, C.F. Sindt, R.R. Wilson, J.D. Siegwarth

At the core of this work is a flow facility capable of providing

accurate and precise mass -based data for flowing liquid nitrogen and ambient

temperature gas. There are three projects currently under study. The first

is designed to provide substantial improvement in the metering of natural gas

by means of orifice and turbine type flowmeters. This multi-year program,

funded by the Gas Research Institute, includes an extensive series of

measurements on 3 and 4- inch diameter orifice meters. Also under

investigation are swirl phenomena, flow conditioning concepts, and pipe

roughness effects. The work in Boulder on gas flow is closely coordinated

with similar work on water flow in the Chemical Process Metrology Division.

6
The second area of flow research uses the flow facility to evaluate new

measurement techniques and to perform special tests on meters to provide

measurement traceability to NBS . These tests are performed with liquid

nitrogen. The third area of flow research is concerned with high velocity

flows (over 50 m/s) and uses water from a local hydroelectric plant since

such velocities are well beyond the range readily available in a laboratory.

The purpose of this work is to assist NASA in developing reliable flowmeters

for the space shuttle propulsion system.

Process Thermodynamics

V.D. Arp, D.E. Daney, M.J. Hiza, P.R. Ludtke

,

J.D. Siegwarth, R.O. Voth

This work is designed to provide engineering, principally cryogenic

engineering, expertise to other government agencies to solve (or provide the

basis for solution of) a variety of problems. Current research is concerned

with 1) reviewing and evaluating thermodynamic modeling of cryogenic systems

in support of high energy physics experiments at the National Accelerator

Laboratory; 2) analyzing the fluid mechanics, thermodynamics, and phase

equilibria, and assessing the applicability of measurement methodology in the

production, transfer, and storage of liquid-solid mixtures of hydrogen; and

3) performing experiments and analyzing the fluid mechanics and thermodynamics related to the transfer and storage of large quantities of fluids

such as liquid hydrogen, oxygen, and superfluid helium with application to

fluid management in low gravity environments. The work in area 1) is

supported by the Department of Energy, in area 2) by the Defense Advanced

Research Projects Administration, and in area 3) by the National Aeronautics

and Space Administration.

PROPERTIES OF SOLIDS GROUP

Cryocooler Studies

R. Radebaugh, P. Bradley, J. O'Keefe, V. Arp, J. Gary*

A pulse tube refrigerator was built under a NASA-Ames contract and

reached a record low temperature of 60 K in one stage. The lowest

temperature previously reached with a pulse tube refrigerator was 105 K. This new work has led to the device becoming a serious alternative to oth.-:

refrigeration schemes that have more moving parts. The pulse tube

refrigerator has only one moving part. A test apparatus to measure’ ; In- efficiency and refrigeration power per unit mass flow has been construe ; .•>: under the same program. Measurements of efficiency and refrigeration

have been made on four different pulse tubes. The results show intrin.-

cooling efficiencies as high as 50 to 90 percent of Carnot in some large refrigeration powers.

7
Under a five-year Air Force (AF) contract, the regenerator test

apparatus was modified to make tests in the presence of pressure waves to

simulate the environment seen by regenerators in an actual refrigerator. A

high specific heat material, GdRh, has been formed into powder for testing as

a regenerator. This material was sent to an AF contractor for tests in an actual refrigerator. It increased the refrigeration power by 23 percent and

decreased the low temperature limit from 7.1 K to 6.2 K. This material is

now being tested in the NBS apparatus. Theoretical and experimental studies

of the effect of the phase angle between compressor and expander pistons on regenerator performance are in progress and indicate overall refrigerator

improvements can be made by a proper choice of phase angle. A computer

program for the first step, optimization of regenerators, has been developed

and the floppy disk for use on a personal computer is available upon request

to the U.S. Air Force.

The least reliable component of present cryocoolers is the mechanical

compressor. A proposed alternative uses a thermal compressor in which the

gas to be compressed is first adsorbed on charcoal at a low pressure. The

charcoal is then heated slightly and the adsorbed gas is driven off at some higher pressure. Only slow-moving check valves are needed to provide

continuous flow in one direction. The necessary data to design a helium- charcoal compressor is lacking, but a program funded by the Air Force

Space Technology Center has allowed us to measure the adsorption

characteristics of helium on charcoal in the temperature range 10 to 77 K.

These results will be published in the journal Cryogenics. Measurements on other charcoals as well as measurements of heats of adsorption are in

progress

Refrigeration reliability can be improved by the use of redundant cryocoolers. This approach requires the use of heat switches between the cryocoolers and the sensor to be cooled. One technique uses pressure contact

between two metals. Required forces are about 13 000 N (3 000 lb). No data

existed on the thermal conductance of such contacts at cryogenic temperatures. With funding from the Air Force Space Technology Center, we have made

measurements on three pairs of metal samples, at temperatures from 10 K to room temperature and with forces from 45 N (10 lb) to 27 000 N (6 000 lb)

The data have been used by an AF contractor for the design of heat switches.

*NBS Center for Applied Mathematics

Metal Combustion in High Pressure Oxygen

J.W. Bransford, K.M. McDermott

A program to study the ignition and combustion characteristics of a number of metals and alloys in high pressure oxygen, at pressures to 14 MPa,

has been undertaken for NASA. This program is not only of interest to NASA

and the aerospace industry, but also to producers, transporters, and industrial users of liquid and gaseous oxygen.

8
The top surface of a cylindrical sample is heated by a focused CO 2 laser

beam. Interior and exterior temperatures are measured before, during, and

after ignition. High-speed movies of the ignition and combustion process are also made

From the above data, spontaneous ignition temperature, ignition

temperature and ignition/combustion morphology can be determined. NASA will

use the results to design safer components for launch vehicles, such as the

Space Shuttle, which use large quantities of liquid oxygen at high pressures.

The results are also directly applicable to industrial handling of high

pressure oxygen.

Thermal Properties of Advanced High-Temperature Materials

L.L. Sparks

Ceramics and ceramic based composites continue to develop as replacements for metals and plastics in electronic components and high

performance engines and structures. Research on these materials has

traditionally been in the areas of processing and mechanical properties.

Thermal properties must be known for advanced applications now being

contemplated or, in some cases, actually incorporated in working designs.

The properties in question include thermal conductivity, thermal expansion,

heat capacity, and thermal diffusivity. Knowledge of these properties is

required to allow ceramics to be used in applications such as unlubricated

bearings, high- temperature reactors, turbine rotors, adiabatic diesel

engines, turbo compressors, thermal barriers, electrical components, and

substrates for electronic components.

Three projects to address these needs are active within the group: (1)

continued development of a steady- state thermal conductivity apparatus to

allow ceramics and ceramic composites to be studied to 1270 K; (2) completion

of a guarded-hot-plate thermal conductivity apparatus to allow ceramic fiber

insulation to be studied to 800 K; and (3) alteration of the existing optical

dilatometer to study foamed ceramics at low temperatures

Oxidation of Metals in High Pressure/Hieh Temperature Oxygen

J.W. Bransford, J.A. Hurley

A program to design and operate a Thermogravimetric/Dif ferential Thar::

Analysis (TGA/DTA) apparatus has been undertaken. The TGA/DTA apparatus,

in the design and construction stage, will be used to directly determine

oxidation rate of various metal alloys in high- temperature and/or highpressure oxygen. The data generated by these studies will be of inter*

all users of oxygen at high temperature and elevated pressure.

9
Development of SRM's

J.G. Hust, J.E. Callanan, D.R. Smith

Research has been directed toward the establishment of several thermal

property Standard Reference Materials (SRM's).

Research for the development of high- temperature insulation SRM's is

funded by DoE. These SRM's will fill an existing gap in the range of available thermal conductivity SRM's and are of interest to researchers and

manufacturers in the chemical and related industries. Microporous and

ceramic fibers are currently being developed as SRM candidates.

Potassium nitrate has been certified as a temperature and enthalpy of

fusion standard for differential scanning calorimetry (DSC) . Auxiliary

measurements have shown it to be useful as a reference material.

A supply of anthraquinone has been obtained and purified for development

as an SRM. The anthraquinone and high-purity cadmium foil are being sampled

for certification.

Test samples of organics and inorganic salts over the higher temperature

range 400-1000 K have been obtained for evaluation as potential standard

reference materials.

Studies of 1) the capability of DSC for development of heat capacity

standards and 2) the energy calibration procedures for DSC have been

completed. Final statistical analysis of these data is being completed in

collaboration with the NBS Statistical Engineering Division.

A statistical study of the ASTM calibration procedures, and variants of

those procedures, resulted in improved estimates of uncertainty limits for

certification. From consideration of the results of this study and the

energy calibration study, improved calibration (correction) procedures are being developed.

Research leading to the development of measurement procedures for heat

capacity and heat of vaporization of volatile liquids and to the potential

development of standard reference materials has been undertaken.

5. PUBLICATIONS

Arp, V.D. and Radebaugh, R. , Interactive program for

microcomputers to calculate the optimum regenerator geometry

for cryocoolers (regen and regen 2), Air Force Wright

Aeronautical Laboratories Report, AFWAL-TR- 87 - 3040 , Wright

Patterson Air Force Base, OH (Aug. 1987).

10
Baird, R.S., Bunge, A.L. and Noble, R.D., Batch extraction of

amines using emulsion liquid membranes -- importance of reaction

reversibility, AIChE J., Vol. 33, pp . 43-53 (Jan. 1987).

Bransford, J.W., Billiard, P.A., Hurley, J.A. and Vazquez, I., The

development of combustion from a quasi-stable temperature for

the iron based alloy UNS S66286, to be published in ASTM

Special Publication.

Brennan, J.A., McManus, S.E., Sindt, C.F., Bateman, B.R., Pantoja,

I.V. and Mann, D., Basic gas metering - annual report, GRI

Contract No. 5081-353-0422 (May 1987).

Brennan, J.A., McManus, S.E., Sindt, C.R. and Kothari, K.M., The

influence of swirling flow on orifice and turbine flowmeter

performance, to be published in Proc . of Int . Symp . on Fluid

Flow Measurement.

Brown, R.J.C., Callanan, J.E., Weir, R.D. and We strum, E.F., Jr.,

The thermodynamics of ammonium scheelites VI. An analysis of

the heat capacity and ancillary data of the metaperiodates

KIO4, NH4IO4 , to be published in J. Chem. Thermodynamics.

Brown, R.J.C., Haslett, T.L., Callanan, J.E., Weir, R.D. and

Westrum, E.F., Jr., The thermodynamics of ammonium scheelites

V. Heat capacity of deuterated ammonium metaperiodate NH4IO4

from 8 to 329 K, J. Chem. Thermodynamics, Vol. 8, No. 1, pp

133-145 (Jan. 1987).

Callanan, J.E., Review of needs for thermophysical property data on solid feedstocks, II. Oil Shale, Nat. Bur. of Stand. (U.S.)

Interim Report 87-3064 (Apr. 1987).

Callanan, J.E. and McDermott, K.M.

,

Specific heat measurements of

two premium coals, ACS Fuel Division, Vol. 32, No. 4, pp . 237-

242 (1987).

Callanan, J.E., Filla, B.J., McDermott, K.M. and Sullivan, S.A.,

Enthalpies of desorption of water from coal surfaces, ACS Fuel

Division, Vol. 32, No. 1, pp . 185-192 (1987).

Callanan, J.E., Sullivan, S.A. and MacDonald, R.A., Experimental

determination and modeling of the heat capacity of coal in

various atmospheres, Int. J. of Thermophys . , Vol. 8, No. 1,

pp. 133-145 (Jan. 1987).

Daney, D.E., Behavior of turbine and venturi flowmeters in

superfluid helium, to be published in Adv. in Cryo . Eng.

11
Daney , D.E. and Maples, E.L., Thermal conductivity of liquid

hydrogen filled foam, Cryogenics, Vol. 27, pp . 427-428 (Aug.

1987) .

Daney, D.E., Cavitation in flowing superfluid helium, to be

published in Cryogenics.

Dube, W.P., Sparks, L.L. and Slifka, A., NBS boil-off

calorimeter for measuring thermal conductivity of insulating

materials, to be published in Adv. in Cryo . Eng.

Hanna, G.J., Noble, R.D. and Michel, F.C., Interfacial resistance

for carboxylic acid transfer from decane to water, J. Phys

Chem. , pp. 362-365, 1987.

Huber, M.L. and Jones, M.C., A frequency response study of packed

bed heat transfer at elevated temperatures, to be published in

J. of Heat and Mass Transfer.

Hust, J.G. and Smith, D.R., A thermocouple device for

determination of average surface temperature, to be published

in J . of Thermal Insulation.

Hust, J.G., Filla, B.J. and Smith, D.R., A modified digital PID

temperature controller for thermal properties measurements, to

be published in J . of Thermal Insulation.

Jin, M. , Sikdar, S.K. and Bischke, S.D., Glycine permeation

through NA+, AG+, and C s + - Forms of perfluorosulfonated ion

exchange membranes, to be published in J . of Separation Sci. &

Tech

Jones, M.C., Giarratano, P.J. and Powers, L.A.

,

Retrograde

condensation of carbon dioxide/N-decane mixtures on horizontal

cylinders, to be published in the ASME/AIChE National Heat

Transfer Conf. Proc

Kirkkopru, A., Noble, R.D. and Bunge, A.L., Amine phase

partitioning using emulsion liquid membranes, to be published

in Chem. Eng. Comm.

Kris, R.D. and Sparks, L.L., Performance of almumina/epoxy thermal

isolation straps, to be published in Adv. in Cryo. Eng.

Ludtke , P.A. and Daney, D.E., Cavitation characteristics of a small

centrifugal pump in Hel and Hell, to be published in

Cryogenics

Ludtke, P.R., Daney, D.E. and Steward, W.E., Centrifugal pump

performance with normal and superfluid helium, to be published

in Proc. of Cryo. Eng. Conf.

12
MacDonald, R.A., Callanan, J.E. and McDermott, K.M.

,

Heat capacity

of a medium-volatile bituminous premium coal from 300-520 K.

Comparison with a high-volatile bituminous nonpremium coal, to

be published in Energy and Fuels.

McManus, S.E., Brennan, J.A. and Sindt, C.F., Effects of abnormal

conditions on accuracy of orifice measurement, to be published

in 1987 Proc. of the Int . Hydrocarbon School.

Noble, R.D. and Danesi, P.R., Steady state coupled transport of

HNO 3 through a hollow fiber supported liquid membrane, to be

published in ACS Symp . Series.

Noble, R.D., An overview of membrane separations, Separation Sci.

and Tech., Vol . 22, Nos. 2 and 3

,

pp

731-743 (1987).

Noble, R.D. and Way, J.D., Liquid membrane technology - an

overview, ACS Symp. Series, Chapter 1, pp . 1-26 (1987).

Perkins, R.A.The partition of single component and binary

component protein mixtures in polyethylene glycol - dextran

aqueous two phase systems, to be published in Biotech, and

Bioeng

Perkins, R.A., Sikdar, S.K., Pandit, A., Sawant, S.B. and Joshi,

J.B., Rheological properties of dextran, polyethylene glycol,

bovine serum albumin and their mixtures, to be published in J.

of Chem. and Eng. Data.

Persichetti, J.M., Steward, W.G. and Arp, V., Thermally induced

convection in narrow channels II. Experimental results for

refrigerant 113, to be published in ASME J. of Heat Transfer.

Radebaugh, R. , High-speed thermometry at cryogenic temperatures, to

be published in Proc. of 17th Int. Congress on Refrig.

Radebaugh, R. and Storch, P., Analytical model of orifice

pulse-tube refrigerator, to be published in Proc. of 17th

Int. Congress on Refrig.

Radebaugh, R. and Herrmann, S., Refrigeration efficiency of

pulse- tube refrigerators, to be published in Proc. of the

Fourth Int. Conf. on Cryocoolers.

Radebaugh, R. , Ineffectiveness of power regenerators in the 10 K

temperature range, to be published in a US Navy Publication.

Inter-agency Conference on Cryocoolers.

Scull, L.L.

,

Arvidson, J.M. and Sparks, L.L., Low temperature

mechanical property and thermal expansion measurements of

silica aerogel foam, to be published in Adv . in Cryo . F.i!;-.

13
Siegwarth, J.D. and Voth, R.O., Cryogenic high vacuum

miniature valve, to be published in Proc . of Cryo . Eng.

Conf

Sikdar, S.K., The world of polycarbonates, Chemtech., Vol. 17, pp

112-118 (1987).

Sindt, C.F., Brennan, J.A. and McFaddin, S.E., NBS research on the

effects of pipe roughness and flow conditioners on the orifice

discharge coefficient, Proc. of the Operating Section of the

Amer. Gas Assoc., 1987.

Slaff, G., Review of the book entitled "Partitioning in aqueous

two -phase systems," to be published in the ACS media.

Storch, P.J. and Radebaugh, R. , Development and experimental test

of an analytical model of the orifice pulse tube refrigerator,

to be published in Adv. in Cryo. Eng.

Vazquez, I., Russell, M.P., Smith, D.R. and Radebaugh, R. , Helium

adsorption on two activated carbons at temperatures between 4

and 76 K, to be published in Adv. in Cryo. Eng.

Voth, R.O., Research required before using slush hydrogen as a NASP

fuel, to be published in Third NASP Technology Symp . Proc.

Voth, R.O. and Siegwarth, J.D., Electronic balance for use at

cryogenic temperatures, to be published in Adv. in Cryo. Eng.

Voth, R.O., Welch, J.F., Bransford, J.W., Arp, V.D. and Hiza, M.J.,

On the review of large cryogenic systems at Fermilab with

regard to safety, to be published as NBS Interim Report.

Way, D.J. and Noble, R.D., Hydrogen sulfide facilitated transport

in perfluorosulfonic acid membranes, ACS Symp. Series, Chap.

9, pp. 123-137 (1987).

Way, J.D., Noble, R.D., Reed, D.L. and Ginley, G.M., Facilitated

transport of CO 2 in ion exchange membranes, AIChE J., Vol. 33,

No. 3, pp. 480-487 (Mar. 1987).

14
6 . CONFERENCES

INFERENCES

The Calorimetry Conference, 42nd Annual Meeting at Boulder, CO, July 26-3

1987 (local arrangements Chairman, J.E. Callanan)

An international conference on Frontiers in Bioprocessing, Boulder, CO, June

28- July 2, 1987. S.K. Sikdar, chaired program committee and co-organized

conference with J. Hord, V. Schrodt, P. Todd (Univ. City Sci. Center) and M.

Bier (U. AZ)

Session [71] on Safety and Reliability of Cryogenic Systems, AIChE Annual

Meeting, Miami, FL, Nov. 5, 1986. Co-organized and co-chaired by J. Hord

15
TECHNICAL ACTIVITIES

OF THE

THERMOPHYSICS DIVISION

N.A. Olien, Chief

1. INTRODUCTION

The research of the Thermophysics Division focuses on the thermodynamic

properties and dynamic behavior of fluids and solids, with particular

emphasis on properties and substances of current and future importance in

chemical engineering.

The approach is to conduct research on fundamental theoretical models, new concepts and phenomena, and predictive algorithms in synergism with

experimental programs. The experimental research is aimed at developing new measurement techniques and providing highly accurate data for the properties

of carefully selected pure fluids and mixtures, as well as high temperature

solids, which are representative of broad classes of fluids and materials

encountered in many industries. An essential ingredient of the above efforts

is the critical evaluation and correlation of data leading to the publication

of Standard Reference Data. Standard Reference Data often take the form of

conventional correlations and tables, but more recently the preferred form is

that of predictive models as computer codes.

All industrial processes and certainly those in the chemical and fuel

industries are steadily moving toward alternative and more complex base

feedstocks, which in turn yield more complex, and often corrosive and

hazardous, conversion products and often involve higher temperature

processes. Modern plants must handle a larger variety of feedstocks and must

produce a broader range of output products. A very significant factor in the

application of the research described here is the widespread use of process

simulation and computer-aided design in the development, optimization, and

control of processes and plants in the chemical, fuel and related industries.

Key ingredients of all process simulators are the data and models for the

properties of fluids and other materials encountered in the processes. Major

outputs of the research program described here are property data in the form

of predictive theoretical models and correlations which can be readily

incorporated into process simulator and process control algorithms.

Thermophysics Division research addresses scientific issues of national

importance for which NBS expertise, and its impartial position, are critical

to data acceptance and to the resolution of problems of equity in trade for

such products as ethylene, natural gas, steam, and carbon dioxide. The

majority of the work is directed toward problems of the future. These

include, but are not restricted to, the following: 1) fluids encountered in

the conversion and utilization of coal, oil shale, heavy oils, and tar sands

to gaseous and liquid feedstocks and fuels which, in turn, contain

substantial amounts of aromatic organics and associating compounds

(containing N, 0, S) ; 2) fluid mixtures encountered in bioprocess

16
engineering, which are essentially aqeuous solutions containing

macromolecules; and 3) high temperature solid and fluid property needs of

government agencies for energy, defense, and aerospace (e.g. DoE , DoD , NASA),

where NBS expertise can provide specific results. The strategy is to perforin

basic research, generic to the science underlying the chemical, fuel, power,

and aerospace industries , which requires the special role of NBS as an impartial national laboratory excelling in experimental and theoretical

results and their interpretation.

2. GOAL

The goal of the Division is to provide standard measurement procedures,

benchmark experimental data, and reliable methods of predicting key

thermophysical properties of industrially important chemicals, fuels, and

related fluids, and of high temperature solids. These data are used in the

innovation, design, and control of chemical processes; to ensure equity in

domestic and international exchange of products; and by NBS and others as benchmark data to extend versatile computational techniques which reliably

predict the properties of broad classes of substances over extended operati:

ranges

The output of this program assists the chemical, fuel, power, aerospac- . and related industries in maintaining and enhancing their competitiveness in

the international marketplace by making their processes more efficient, more able to accept a broader array of input feedstocks, and by providing avenue

to the development of new products

3 . GROUP AND PROGRAM FUNCTIONS

The research of the Division is performed within two groups and one Division Office program.

GROUPS

° Equation of State and Statistical Physics (Gaithersburg, MD)

R.F. Kayser, Group Leader

This Group conducts experimental, theoretical, and computer si:rul., • studies of the thermodynamic and transport properties of fluids, fluid

mixtures, and solids, including supercritical and aqueous systems; pr>!.-,i

fluids and mixtures; interfaces and wetting layers; and liquids, gl • molecular aggregates. The Group develops new measurement techniques,

thermodynamic models, and molecular theories to describe the th( : :: behavior of condensed matter, and provides critically evaluated

information (data, theoretical models, computer models) on these

thermophysical properties. Major non-CCE sponsors of the work <>: include the DoE, NASA, and the NBS Office of Standard Reference ! ,

i

17
o Properties of Fluids (Boulder, CO)-W.M. Haynes, Group Leader

This Group has a research program which integrates experimental

measurements, theoretical studies, and critical evaluation of data, all

designed to lead to a basic understanding of fluid behavior. Outputs are data and theoretically-based predictive models for the properties of

technically important complex mixtures and pure fluids. The fluids of

interest include common inorganics, industrial chemicals, hydrocarbons, coal

conversion products, heavy oils, and biochemical solutions. Principal non- CCE sponsors of the work of this Group include the DoE, the Gas Research

Institute, the DoD , industrial consortia, and the OSRD.

DIVISION OFFICE PROGRAM

o Dynamic Measurements (Gaithersburg, MD)-A. Cezairliyan, Project

Leader

This program develops dynamic (millisecond and microsecond) measurement

techniques and performs measurements of selected thermophysical properties of

high temperature materials over the range 1500 - 10 000 K. Materials

investigated include high temperature conductors and nonconductors,

refractory materials, metallic composites, and high temperature Standard

Reference Materials. The unique capabilities of this laboratory provide the means to perform accurate measurements in temperature regimes and at high

heating rates where conventional techniques fail.

4. SELECTED PROJECT SUMMARIES

EQUATION OF STATE AND STATISTICAL PHYSICS GROUP

Aqueous Systems at High Pressures and Temperatures

J.M.H. Levelt Sengers , J.S. Gallagher, G. Morrison, M.L. Japas (Guest

Scientist). Collaborator: P. Schiebener (Technical Univ. of Munich)

One group of activities in the past year was related to the interests of

the International Association for Properties of Steam, with Levelt Sengers

chairing Working Group A on pure steam and aqueous systems. With IAPSsponsored visitor Schiebener, a new correlation of the refractive index of

water and steam was completed as a function of pressure, temperature, and

wavelength, and compared with all literature data of the past 100 years. A

report was prepared for IAPS and is being shaped into a publication for J.

Phys . Chem. Ref. Data. With Japas and Garvin (Chemical Thermodynamics

Division of NBS) a beginning was made with reformulation of the dielectric

constant of water, a property whose derivatives enter all correlations of

aqueous electrolyte properties. A one-day seminar on properties and

industrial problems of solutions in high- temperature steam was coorganized by

Levelt Sengers at the IAPS meeting, September 1987, Reading, UK.

Another group of activities continued to center around aqueous mixtures

With Gallagher, the apparent molar properties and phase boundaries of dilute

18
NaCl in high temperature water are being mapped onto the known properties of

pure water. With Japas, the anomalous solubility of gases in hightemperature water is being formulated.

An invited talk was given by Levelt Sengers at the Airlie House

Conference on the Thermodynamics of Aqueous Systems, May 1987, and a paper is

being finalized for the proceedings of the meeting. Morrison spoke at the

BYU Symposium on Chemistry in High Temperature Solutions, August 1987, and

has finished a first draft for the Proceedings.

Thermodynamic Properties of Fluid Mixtures

L.A. Weber, E.J. Clark, G. Morrison, J.S. Gallagher, J.L. Manley, J.M.H.

Levelt Sengers, M. Patron (Guest Scientist).

Collaborator: C. Peters (Univ. of Delft)

The work on characterization of the system isobutane - isopentane , a geothermal working fluid mixture, was completed, and several publications

(including an article in the Review of Scientific Instruments) and

presentations at AIChE meetings resulted.

The PVT apparatus was dismantled, repaired, and modified for study of

the mixture CO 2 -C 2 H5

. The VLE apparatus was thoroughly cleaned and a larg<-

number of improvements were made in the hardware and in the interface with

the computer.

In a NATO collaboration with Peters, the Donohue perturbed-hard- sphe :• model has been successfully applied to mixtures of small and long n-alkai • A paper was written for presentation at the New York AIChE meeting. Work

ongoing on the calculation of critical curves and three-phase boundaries.

With scientists at the University of Maryland, collaborative program';

have been set up on crossover in pure fluids and mixtures. A large number <>: joint tutorials have been held. Work has begun on crossover in refrigera:

New work is starting on the development of a high-pressure dilatomo ;

< also, we are studying the feasibility of preparing extended- chain polymer

fibers from pressurized solutions.

Electrophoretic Light Scattering From Macromolecular Solmi o: 1

• and Colloidal Dispersions

J.B. Hubbard, A.K. Gaigalas*, S. Woo*

The analysis of quasielasticly scattered laser light from a salt

containing solution in the presence of an external electric field I- electrophoretic light scattering (ELS). In an "ideal" colloid.il cl: or macromolecular solution, the Lorentzian half -width gives the diffu- • t t coefficient while the Doppler shift gives the mobility, wh i < h < an • related to the surface charge of a particle. ELS is superior to < . • light scattering because of the ease of resolving mixtures whoM- <

19
have different surface charges. Compared to gel electrophoresis, ELS is a sensitive in-situ diagnostic probe rather than a separation technique. In

ELS, no concentration gradients are produced, the fluid medium is wellcharacterized, and very large particles such as cells or bubbles are not

trapped as in a gel. We have begun an experimental ELS study of latex sphere

dispersions in electrolyte solutions to test our equipment design and to

scrutinize current theories. In addition, we have recently published a theoretical analysis of the effects of conformational dynamics of solvated

macromolecules on the observed spectrum. The idea is that one can use ELS to

simultaneously monitor both the statics and dynamics of biologically

significant conformational changes, such as protein denaturations . As a future project, we plan a novel study of ELS in a gel-like medium as a direct

probe of particle -gel dynamical interactions.

•^Chemical Process Metrology Division, NBS/CCE

Computer Simulation Studies of Liquids and Solids

R.D. Mountain, J.G. Amar

The molecular level computer simulation of the properties of liquids has

proven to be an essential technique for utilizing formal, statistical

mechanics -based models of condensed matter. We have an active program which

both develops and utilizes simulation methods to model thermal properties in

terms of the molecular level interactions. The NBS supercomputer is an essential resource for this work. During the past year, our efforts have

been directed towards various aspects of supercooled liquids, towards the

simulation of molecular fluids, and towards the study of the growth of

particulates by aggregation of matter. The work on molecular fluids ties in

closely with Thermophysics Division work on refrigerant mixtures and on properties of dilute water mixtures at elevated temperatures. The

aggregation study is a collaborative effort with the NBS Center for Fire

Research

An extensive study of the supercooled liquid state of a simple model

system was undertaken to identify those features which would distinguish the

supercooled liquid from the equilibrium liquid. Some atomic-level properties

associated with shear were found to do this. We also made a start on the

study of glass formation using a simple model of a binary mixture. The

objective is to guide the development of dynamical theories of glass

formation. Another project studied the time -development of composition

domains in a phase separating mixture. The results clarified the theoretical

picture and indicated that the existing phenomenological theory is adequate.

Work has continued on the study of infrared absorption in liquid mixtures.

Some experimentally observed features continue to not be described by the

models studied, indicating the need for some careful thought about the

physical processes being modeled. We have developed a set of effective

potential functions for two refrigerants, dicholordifluorome thane (R12) and

chlorodifluorome thane (R22) . These potentials will be used to model the

thermal properties of mixtures of these liquids. Particulates, such as soot

particles, grow through the aggregation of other particles. Our modeling of

this process is being used to study the kinetics of the growth process and to

20
aid in the development of light scattering as a diagnostic probe of

particulate size and structure. The structure is characterized by a "fractal" or Hausdorf dimension on the order of 1.8.

Low-Frequency. Low-Shear Rate Viscosity Measurements

R.F. Berg, M.R. Moldover

Collaborators: A. Voronel (Univ. of Tel Aviv), J.S. Huang (Exxon)

As part of a NASA- sponsored project for testing the theory of dynamic

critical phenomena we have developed a unique viscometer. The viscometer is a torsion oscillator which operates at a low-frequency (0.5 Hz) and a low

shear rate (0.05 s'^) . The viscometer has extremely precise temperature

control in the range (-100°C to +100°C) and has been used with fluids at

pressures up to 10 MPa. As part of the NASA project, we have measured the

viscosity of four binary mixtures near their consolute points. These

mixtures have viscosity enhancements that, according to theory, should be of

the same form in liquid-vapor systems near critical points. In the past year

we have exploited the viscometer for two other projects. (1) We measured tht

viscosity of two liquid alkali metal alloys which freeze at temperatures near

-80°C. This work was directed toward testing a theory of glass formation in

alloys. (2) In collaboration with J.S. Huang, we measured the viscosity

enhancements found in a microemulsion in association with a critical point

and with a percolation transition. The measurements showed that most of tie

viscosity increase is related to the percolation transition. Microemuls ion are under study in industry for their application to enhanced oil recover;.'

delivery of pharmaceuticals, and advanced separation processes. The unique

capabilities of our instrument are ideal for this and any other shear

sensitive system.

Spherical Acoustic Resonators for Thermophvsical Properties

and Standards Measurements

M.R. Moldover, B.A. Younglove , N.V. Frederick

Collaborators: R. Davis*, J.B. Mehl (Univ. of Delaware),

J.P.M. Trusler (University College, London)

A new determination of the universal gas constant, R, has led to the

value: R = (8.314471+0.000014) J mol‘^ K"^. The standard error of this

result, 1.7 parts per million, is 5 times smaller than that of the best

previous value of R. The new value of R leads to a 5-fold improvement ii. values of the Boltzmann constant, k = (1 . 3806513+0 . 0000025)xl0'^ J

J K

• the Stefan-Boltzmann constant, a = ( 5 . 670399+0 . 000038 )+10 ' ° W m'

, K'

* more accurate values of R, k, and a will be most useful for primary

thermometry (e.g. gas, noise, acoustic, and radiation thermometry) with

thermometers whose design does not permit them to be used at the ten;,

of the triple point of water, 273.16 K, where the thermodynamic temp* r scale is defined.

We have compared the 1/8 -liter spherical acoustic resonator : .* been transferred from Gaithersburg to Boulder in March 1985 with : b< cylindrical resonator that was used for speed of sound measur* :r.-i

•

21
Boulder. We conducted the comparison with a me thane -ethane mixture in the

pressure range 0-3.4 MPa and in the temperature range 300 K-350 K. The speed

of sound determined by the two independent measuring systems differed by

0.02% at the lowest pressures and 0.05% at the highest pressures. Such small

differences between independent measurements are rare. This comparison was part of a DoE- sponsored project to develop techniques to measure the speed of

sound in industrially important gases at high temperatures.

*NBS Center for Basic Standards

Refrigerant Mixtures - Measurement and Modeling

G. Morrison, J.S. Gallagher

Collaborators: D. Didion*, M.O. McLinden*

The use of refrigerants, chlorofluorinated hydrocarbons (CFC's), has an economic and ecological dilemma of millennial proportions. The use of CFC's

profoundly influences our lives, from "comfort" uses, to climate control for

the electronic equipment that characterizes our technological age, to the

storage of food and temperature sensitive materials such as medicines, blood

products, and organs for surgical transplants. There is evidence that the

leakage of two major refrigerants, Rll and R12 , beyond the tropopause could

lead to the eventual destruction of the ozone layer, which removes the highenergy component of the ultraviolet part of the solar spectrum. The presence

of these wavelengths in ambient sunlight would increase the incidence of skin

cancers, affect plant growth, and modify lower atmospheric chemistry. In

recognition of the importance of room- temperature working fluids and the

consequences of the continued use of Rll and R12 , an international treaty to

reduce their use has recently been signed by the U.S.

A satisfactory substitute must meet a variety of criteria. In addition

to the appropriate thermophysical properties, it must be non- toxic, non- combustible, non-corrosive, and stable at elevated temperatures in the

presence of traces of water, and in the presence of high electric fields. An

analysis of over 800 compounds, indicates, ironically, that the only

satisfactory substitutes will likely be fluorinated hydrocarbons.

G. Morrison has made a survey of silicon compounds; there were no obvious

candidates from that group. Despite the relative simplicity of CFC's and

their economic significance, there is little experimental information about

all but a few of them; information about their mixtures is even more meager.

The cooperative program with the NBS Center for Building Technology is

making a two -front attack on this problem. We have used a modified Carnahan

Starling equation of state to generate accurate thermodynamic surfaces for

the pure materials. The modified equation is simple and has a firm physical

foundation. M. Patron and J.V. Sengers have begun the application of a cross-over algorithm to the equation of state. This modification would

compensate for the shortcomings of a classical equation in the critical

region, and it would be the first application of the recently developed

Albright/Sengers prescription to a practical equation of state. The same equation of state has been modified for mixtures. Considerable progress has

22
been made in predicting the properties of mixtures. The mixture equation of

state and the phase diagram algorithms and equation of state parameters

published in the Morrison/McLinden NBS Technical Note of 1986 have been used

by J . Gallagher to produce a set of 17 thermodynamic charts of 3 pure

materials and 7 mixtures. In addition, measurements are being made on both

pure and mixed refrigerant materials to check older data and to expand the

data base. Work has begun on materials, both pure and mixed, that are likely

candidates to replace Rll, R12, and R22 as working fluids.

*NBS Center for Building Technology

The Langmuir Film Balance

G. Morrison

Collaborator: I.L. Pegg (Catholic Univ.)

The Langmuir film balance measures the surface tension of water

insoluble surfactant monolayers. It can also be used to prepare monolayers

in well characterized states for a variety of optical, mechanical, and

chemical experiments. The surfactants typically studied with this

instrument, molecules that contain one or more highly polar groups attached

to large apolar moieties, are characteristic of the species encountered in

cell membranes, micellar systems, certain classes of emulsions, and liquid

membranes, systems that have obvious biological functions as well as industrial applications. Although these systems are often multilayer in

structure, measurements on the monolayer provide a means of making direct

measurements of molecular, mechanical, and phase properties that can only be

inferred from measurements on the more complex system in- situ.

The film balance developed and constructed at NBS is a computer

interfaced instrument in which many of the problems associated with older

instruments - surface active contamination, temperature gradients, saturation

of the vapor above the film, and tedium of measurement - have been

substantially minimized. The instrument also has a robust semiconductor

sensor that allows surface tensions to be measured over nearly five orders o: magnitude. Measurements made on this instrument during its development hav.

verified recent measurements on the nature of certain phase transitions in

the liquid phase of the monolayer - a discovery that has eluded researchers

for nearly eighty years. Other measurements on this instrument have shown

that the classic studies of liquid-vapor equilibrium in the monolayer were seriously compromised by surface active contamination. Both these

measurements were done as a matter of the normal operation of the instrum

and without the excessive and distracting precautions needed on older stvl<

instruments

The NBS Langmuir balance offers the opportunity to study phenomena in

detail that has not been possible in the past and to measure fundament./,

thermophysical properties of pure and mixed monolayers without be i ng

compromised by uncontrolled artifacts. Any fine measurement has the rr . i that it will lead to a better quantitative understanding of a material : phenomenon; the understanding of these monolayers is presently not i

23
established. In addition, however, the measurements offer the opportunity of

establishing a set of standard reference data on an important class of

materials

Interfacial Phenomena

M.R. Moldover, J.W. Schmidt, R.F. Kayser, J.C. Rainwater

The program on interfacial phenomena addresses industrially important

problems in liquid- solid , liquid- liquid, and liquid-vapor interfaces using

modeling, theory, and experiment. The work has led to 14 publications and 25

invitations to speak within the past year.

In the area of modeling, the theoretically motivated RainwaterMoldover-Gallagher correlation of VLE data for binary mixtures was extended

to include interfacial tension. The extended VLE correlation was shown to

predict the interfacial tension in mixtures of CO 2 + butane within

experimental accuracy. The method is applicable immediately to the 27 binary

mixtures, including refrigerants, for which Rainwater has correlated VLE

surfaces in the extended critical region. The interfacial tensions of

refrigerants are used to predict heat transfer in heating and air

conditioning equipment; the interfacial tensions of mixtures such as CO 2 + butane are used to model petroleum reservoirs.

Theoretical efforts have focused on general mechanisms for stabilizing

thin liquid films against external fields such as gravity. Much progress has

been made in understanding the role of dispersion forces quantitatively, and

the work has expanded to include the effects of electrical double layer

forces. New results include a calculation of the thickness of highdielectric-constant wetting layers that form on solids immersed in

electrolyte solutions and a calculation of the difference between the surface

tension of a charged interface and of the same interface when uncharged. The

results apply to mixtures of polar and nonpolar molecules in contact with

technologically important substrates such as glass.

A state-of-the-art ellipsometer has been used to study the interface

between the liquid phases of two binary mixtures (CS 2 + CH 3 OH and CgHp 2 +

CH 3 OH) , the goal being to distinguish between two schools of thought

concerning fluid interfaces. One class of theories predicts that the

interfacial tension is not a strong function of the area of the interface,

whereas another predicts substantial increases in the interfacial tension

when an interface is confined to a small area, as in a pore. The predicted

increase depends upon the smallest possible length of capillary waves. A

preliminary analysis of our data shows that capillary waves can be defined to

a length scale that is approximately twice the bulk correlation length. If

this result is sustained by a more sophisticated analysis, it implies that an interface confined to a very small pore or nucleating droplet could have an interfacial tension as much as 8 times that of the macroscopic interface.

24
PROPERTIES OF FLUIDS GROUP

Corresponding States Theories of Fluid Mixtures

J.F. Ely, J.R. Fox, R.D. McCarty, M.L. Huber, T.S. Storvick (Guest Scientist)

Collaborators: D. Erickson (Rice Univ.), R.T. Jacobsen (Univ. of Idaho)

In recent years there have been great advances in our microscopic

understanding of fluid mixture behavior. Nonetheless, one of the most

reliable methods for predicting mixture thermophysical properties is based on corresponding states concepts which were theoretically formulated many years

ago. In this project, we are attempting to further improve corresponding

states models for systems which contain large size and polarity differences.

The approach incorporates computer simulations for model mixtures which

provide the radial distribution function as well as other thermodynamic data.

Theoretical approximations are then made for the radial distribution

functions with the results being incorporated into the statistical mechanical

expressions for various properties. Thus far, we have developed an equation

of state model which is nearly exact for model Lennard- Jones mixtures with

size ratios up to two. Current work involves extending these results to real

fluids

An original and radically new approach to the improvement of

corresponding states methods is being developed. The resulting "field space"

transformations describe fluid mixtures in terms of the behavior of a pure

fluid in a fashion very similar to traditional "one fluid" corresponding

states theories, but with two important differences. The structure of

traditional corresponding states methods leads to nonphysical predictions for

the properties of dilute mixtures when coupled to the most accurate pure

fluid correlations. This is corrected in the new structure. The calculat Lot. of phase equilibria is numerically simplified in the new forms, possibly

leading to significant savings in design and process simulation work. A

version of the theory, with the pure fluid described by a cubic equation of

state, is currently being tested with experimental binary mixture data.

Supercritical Fluid Properties

J.F. Ely, J.W. Magee, M.L. Huber, T.J. Bruno, W.M. Haynes

Collaborators: J. Sherman*, L. Chu*, R. Baldwin*, D. Erickson (Rice Univ. t

Industrial interest in enhanced oil recovery using near-critical carle,

dioxide, in supercritical fluid extraction of fuel materials and foods:',::

and in near-critical custody transfer of commercial chemicals has pointed

the need for accurate data and predictive models for supercritical fluid

mixtures. Currently four projects are underway which address various as; of supercritical fluid properties.

The first project, which is sponsored by a consortium of four com; tt one trade organization and NBS , deals with the measurement and com la?

PVTx data for carbon dioxide-rich mixtures. Thus far, experiment .1 been obtained for one ternary and three binary mixtures. In add it ia

predictive model for the thermophysical properties of these systems has •

25
developed that is more accurate in the near-critical region than earlier

models

In the second project, a base of high accuracy, nonanalytic equations of

state has been developed for various pure fluids. Most recently, equations

for methane, n-pentane and carbon dioxide have been obtained. In the near

future rescaled 32 -term BWR equations will also be available for normal and

isobutane

In the third project, supercritical solubility data for high value coal

liquids such as creosols have been obtained in a flow equilibrium apparatus.

Various solvents (and co-solvents) have been investigated as to their value

in extracting these materials. Work is currently underway to model this

equilibrium data with an equation of state designed for polar fluids.

Finally, in the fourth project, a supercritical fluid chromatograph has

been developed as a tool for physicochemical measurements. Supercritical

fluid chromatography assumes a natural role in thermophysics research as an intermediary between gas chromatography and high performance liquid

chromatography. The supercritical fluid chromatograph is being used for

studies of diffusion phenomena, solubilities, and partial molar volumes.

^Colorado School of Mines

Predictive Computer Packages

J.F. Ely, R.D. McCarty

Collaborator: R.T. Jacobsen (Univ. of Idaho)

One of the primary outputs of the group is a collection of predictive

and/or correlative computer programs which are packaged for end use by

practitioners in science and engineering. Primary packages of this nature

which have been distributed in the past year are MIPROPS , DDMIX, C02PAC and

SUPERTRAPP. All of these programs are interactive in nature and designed to

be user friendly and useable on microcomputers as well as mainframes.

MIPROPS is a program which calculates the thermodynamic and transport

properties of twelve pure substances. DDMIX calculates the thermophysical

properties of mixtures (up to seventeen components) with the emphasis placed

on highly accurate mixture densities. C02PAC calculates the properties of

pure carbon dioxide using the Schmidt -Wagner equation of state formalism.

Finally, SUPERTRAPP calculates the thermophysical properties of mixtures (up

to twenty components from a list of 125) using the extended corresponding

states model. All of these, except C02PAC, are available from the NBS Office

of Standard Reference Data for a nominal charge.

As new models and results are obtained, the list of programs and their

ultimate utility will grow. The extended corresponding states model has

recently been used in the development of computer packages for air and for

mixtures of metallic hexafluorides and perfluorinated hydrocarbons. The

power of the extended corresponding states method (using shape factors) for

26
predictions has been demonstrated in the development of these latter two

packages, for which experimental data are extremely limited or nonexistent.

The work on air properties has also led to a substantial experimental project

to improve the quality of low temperature data for air and related mixtures.

Complex Fluid Systems

J.F. Ely, M.L. Huber, R.A. Perkins*, A.J. Kidnay, G.C. Straty,

T.J. Bruno, R.D. Goodwin

Collaborator: G.A. Mansoori (Univ. of Illinois)

Fluid property research has been moving rapidly in the direction of the

study of ever more complex systems. As a result, new experimental techniques

and theoretical methods are being developed to handle such systems

Currently, one part of this effort involves the behavior of biological fluid

mixtures. Aqueous two-phase partitioning has been analyzed from a molecular

point of view, and statistical mechanical models have been investigated for

the interpretation and prediction of such phenomena. Using experimental data

for the polyethylene glycol -dextran-water system, it has been shown that

these models qualitatively predict the general features of the phase behavior

of these systems although the current models fail to provide quantitatively

accurate results

Heat of mixing measurements are being made on a series of f ive -membered

ring compounds (furan, tetrahydrofuran , thiophene, tetrahydrothiophene

,

pyrrole, and pyrrolidine) to examine the effects of hydrogen bonding in

aromatic liquids and liquid mixtures. These data will aid in the development

of the theoretical means of predicting the thermophysical properties of broad

classes of these mixtures.

Another area of recent work is the thermophysical properties of reactin

fluids. Under conditions of high temperature and high pressure, even simple

fluids can undergo extensive chemical decomposition. A comprehensive

analytical and reaction screening facility has been developed to help

characterize the behavior of these systems. Experimental data and subsequent

correlations have been provided for methanol, benzene, and toluene.

Protocols for characterizing reacting fluids, for performing reproducible

measurements on them, and for reporting data from such measurements have bee:

proposed.

^Chemical Engineering Science Division, NBS/CCE

27
PVT Measurements and Correlation

J.W. Magee, W.M. Haynes, G.C. Straty, R.D. Goodwin, J.F. Ely,

D.G. Friend, R.D. McCarty, H. Ingham, N.V. Frederick, R.D. Goodwin

Collaborators: R. Masui (Nat. Research Lab. of Metrology, Japan),

J. Sherman (Colorado School of Mines)

The group has four operational apparatus to measure the PVT properties

of fluids: an automated isochoric PVT cell operating between 80 K and 450 K

for pressures to 35 MPa; a high temperature, isochoric-Burnett expansion PVT

cell for 300 K to 900 K with pressures to 50 MPa; a low temperature magnetic

suspension densimeter operating between 80 K and 320 K at pressures to 35

MPa; and an automated balance densimeter for 300 K to 500 K at pressures to

20 MPa. Recent results have been obtained for CO 2 , CO 2 + N 2 , CO 2 + CH4 , CO 2 + N2 + CH4 , CO 2 + C 2 Hg , R-13, methanol, benzene, and toluene. Planned

measurements include carbon dioxide plus hydrocarbons, N2 + O 2 + Ar (air),

hydrocarbon mixtures simulating natural gas, pentanes, and binary mixtures

with components exhibiting large differences in size and/or polarity.

A primary output of the group is the correlation of PVT data.

Comprehensive correlations have been completed for methanol, benzene, and

toluene using a nonanalytic equation of state. The Schmidt-Wagner equation

of state has been applied to light hydrocarbons and carbon dioxide with

excellent results, especially in the extended critical region. The 32- term

modified BWR equation, which has been used extensively for many fluids, is

currently being applied to monomethylhydrazine

Phase Equilibria Studies

V.G. Niesen, J.E. Mayrath, T.J. Bruno, M.J. Hiza, J.C. Rainwater

Accurate phase equilibria data and models are essential in the design

and operation of separation units in the chemical process industry. Several

apparatus are available in our group for the acquisition of such data. A

moderate temperature (300 K to 450 K) phase equilibria apparatus has been

modified to include measurement of liquid and vapor phase densities using

vibrating tube densimeters. After calibration with nitrogen and water at

temperatures from 300 K to 400 K, for pressures to 14 MPa, and densities

between 0 and 1 g/cm^ , the apparatus was tested with measurements on carbon

dioxide, normal butane, and their mixtures. Both the phase behavior and

density results agreed within experimental uncertainty with reliable

literature values. Other recent measurements have included butanes with

refrigerant R-13. Future measurements will include binary mixtures of

nitrogen and normal butane, and then ternary mixtures of nitrogen, carbon

dioxide, and normal butane.

A phase equilibria apparatus for measuring dew and bubble point

pressures from 325 K to 800 K at pressures to 35 MPa has been recently used

to obtain data for the methanol and water system over the range 350 K to 650

K. This automated apparatus is unique in that residence times have been

minimized for fluids that react or decompose at high temperatures and no

28
sampling is required after a known composition is introduced and maintained

in the cell. Construction of a differential refractometer cell for use at

high pressures (70 MPa) and high temperatures (800 K) has been initiated.

This technique will provide a real time, non- destructive means for the

determination of binary mixture compositions at extreme conditions

encountered in new technologies in the energy industry.

An apparatus is available for measurement of the fugacity of binary

mixtures containing hydrogen. This technique employs a semipermeable

membrane (palladium/silver) through which hydrogen, but not the second

component, can penetrate. By measuring the properties of pure hydrogen, the

fugacity of hydrogen in the mixture can be determined. Results have been

obtained for hydrogen with methane, ethane, propane, CO 2 , and CO.

Measurements are now in progress for hydrogen and ethylene; a study of the

hydrogen and ammonia system will follow. Our low temperature VLE apparatus

is currently being reactivated for measurements on mixtures of air

components

Accurate correlation of VLE data in the critical region is extremely

important in many industrial applications. It is precisely within this

region that conventional methods fail to converge and/or are inaccurate. A

model first developed by Leung and Griffiths has been modified to provide

accurate correlations of phase equilibria data that cover an extended

critical region from the critical pressure locus to about half the critical

pressure. This model has been successfully applied to a large number of

binary mixtures containing helium, nitrogen, oxygen, carbon dioxide, hydrogen

sulfide, benzene, refrigerants, alkanes, olefins, alcohols, and ethers. The

model has recently been extended to a ternary mixture of ethane, n-butane,

and n-pentane and has been used to predict interfacial tension. A

mathematically complex model has been derived to accomodate VLE in the

presence of liquid- liquid equilibria (LLE) . Future plans include extension

to azeotropic systems and to the one-phase supercritical region, correlation

of coexisting enthalpy data, and development of predictive techniques using

this model.

Thermodynamic Property Measurements and Correlation

J.W. Magee, B.A. Younglove , J.E. Mayrath, H.M. Roder, R.D. McCarty,

N.V. Frederick, M.R. Moldover

There is an awareness in industry that data for the derived

thermodynamic properties (e.g., heat capacity, velocity of sound, enthalpy

of even simple fluids and mixtures are sparse. Further, the prediction'

such properties from an equation of state are unreliable without da;.,

check and optimize the forecasts. Isochoric heat capacity data have l>. obtained for three mixtures of CH4 and C 2 Hg from 100 K to 320 K at pn • to 35 MPa. When combined with previous data on pure CH4 and C 2 Hg . a !.• capacity data base consisting of five compositions has been assembled (<:

development and testing of theoretically based predictive mode]'.,

results are of immediate relevance since the CH4 + C 2 Hg binary

most important binary system in the natural gas industry. Cy in- ,

29
air and mixtures of CO 2 and C 2 H5 will be initiated in the near future. We

will also soon have the transient hot-wire apparatus for obtaining heat

capacity, Cp , results over wide ranges of the fluid surface.

The natural gas industry is very interested in using sonic nozzles as secondary flow measurement standards, but has been hampered by the lack of

accurate sound speed data upon which to base performance. Using a cylindrical resonator, sound speed measurements have been made on twelve

gaseous binary mixtures of natural gas components, with methane as the major

constituent, and on four multicomponent mixtures simulating compositions of

industrial importance. These measurements cover a temperature range from 250

K to 350 K at pressures to 10 MPa. These results represent the only accurate

sound speed measurements for gaseous mixtures other than air. These data are being used to develop a highly accurate predictive model for sound speeds in

natural gas and similiar mixtures.

A new spherical resonator is being constructed for wide-range sound

speed measurement from 80 K to 400 K at pressures to 10 MPa. This apparatus,

which will greatly expand our existing capabilites, will require innovative

development of transducers suitable for high temperatures and high pressures.

The data obtained from this apparatus will aid in the advancement of flow

metering and the development of predictive models

Transport Property Measurements. Correlations, and Theory

D.E. Diller, H.M. Roder, D.G. Friend, J.C. Rainwater

Collaborators: C.A. Nieto de Castro (Lisbon Univ.), W.A. Wakeham

(Imperial College)

In recent years industry has become increasingly aware that transport

properties play a significant role in process design and that accurate

knowledge of these properties can lead to substantial economic benefit. Our

work on transport properties of fluids encompasses the development of new measurement techniques, the utilization of advanced apparatus to obtain

accurate data, the correlation of available transport property data,

theoretical studies of kinetic and transport theory, and the development of

wide-range predictive models for transport properties. Measurements of

viscosity and thermal conductivity are vital to complete the data base needed

by the design engineer and correlator and are a necessary adjunct to PVT and

thermodynamic properties. Further, the study of the transport coefficients

is interesting from a scientific standpoint as it demonstrates the behavior

of a fluid not in equilibrium.

We have an ongoing program to measure the viscosities of dense fluids

and fluid mixtures, from 80 K to 700 K, with pressures to 35 MPa, using two

different piezoelectric quartz crystal viscometers. Our new high temperature

viscometer has recently been performance tested with measurements on compressed gaseous argon and methane at temperatures to 500 K and pressures

to 50 MPa. Measurements on ethane, carbon dioxide, and their mixtures are scheduled next with this apparatus. The low temperature viscometer has

recently been used to obtain viscosity data for liquid toluene at

30
temperatures from 185 K to 320 K. These data have again demonstrated the

power of examining the dependence of the fluidity (viscosity of liquids on molar volume and using this representation as a simple method for correlating

viscosity data for liquids.

For accurate thermal conductivity measurements the transient hot-wire

technique is recognized as state-of-the-art. Our hot-wire apparatus covers

temperatures from 80 K to 330 K at pressures up to 70 MPa. During the past

year we have concentrated on obtaining results for the thermal diffusivity

and the specific heat, Cp , along with the thermal conductivity, using the

transient hot-wire apparatus. So far we have carried out measurements for

argon and nitrogen in the low temperature apparatus with an average error of

5% in Cp and less than 1% in the thermal conductivity. In addition, a new

high temperature transient hot-wire thermal conductivity apparatus is nearing

completion. It will operate at temperatures between 300 K and 775 K with

pressures up to 70 MPa. After testing with argon and nitrogen, measurements

of standard reference quality are planned on toluene and benzene.

We have recently completed new correlations for the thermal conductivity

and viscosity of methane and argon. Dilute gas data are represented with

theoretically-based kinetic theory expressions. The critical enhancement

contribution to the thermal conductivity has also been modeled with an expression with strong theoretical foundation. Finally, the excess contributions for both transport coefficients have been described with

polynomial functions that represent the data within experimental uncertainty.

Analogous studies for ethane, propane, and the butanes are in progess. The

transport properties of binary mixtures of methane and ethane have been

studied experimentallly in this laboratory; a correlation of the thermal

conductivity surface was published during 1987, and a study of the mixture

viscosity surface has now been completed.

There is an ongoing effort to develop an improved theory for the

critical enhancement in the thermal conductivity of mixtures, which has been

observed experimentally in this laboratory. Finally, we have in recent years

developed the first successful microscopic theory of the initial density

corrections to viscosity and thermal conductivity. Calculations of

generalized collision integrals have been extended to lower reduced

temperatures and show good agreement with recent data for benzene and

methanol vapor.

Neutron Scattering

H.J.M. Hanley, G.C. Straty

Collaborators: J. Hayter*, C. Glinka-*'*, N. Clark (Univ. of Colorado), D. Aastuen (Univ. of Colorado)

This work is an experimental part of a large-scale program in our Division to study complex liquids. It is carried out in conjunction with

theoretical work on the structure of liquids and is concerned with the

similarities and differences between "simple" and "complex" fluids. Unspecific objective is to examine long-range correlative or collective

31
molecular motion in the liquid via the structure factor, S(Q), using neutron

diffraction. Test fluids for the past year were glycerol and a suspension of

latex spheres in water. Glycerol was selected because it can be made to

behave as a simple or a complex liquid by varying the temperature. The latex

spheres- -since they make a well-defined system- -were used to get benchmark

data

Specific tasks carried out during the past year were: (a) measurement

of S(Q) for glycerol in the temperature range 175 K to 300 K on the NBS SANS

(small angle neutron scattering) and NBS BT6 spectrometers; (b) measurement

of S(Q) for the latex suspensions on the NBS SANS at very high concentrations -- information on polydispersivity and "glass" formation resulted; and

(c) design and partial testing of a cell to study glycerol under shear via

neutrons, and design and partial testing of a shearing cell for use with

colloids and/or polymers. With regard to (c)

,

results from these apparatus

will be most instructive and essential to understanding the microstructure of

liquids and to meet our objective of differentiating between simple and

complex liquids. Furthermore, the cells will upgrade the capability of the

NBS reactor facility to handle fluids in nonequilibrium. There is strong

industrial and biological interest in shearing equipment.

*0ak Ridge National Laboratory **NBS Institute for Materials Science and

Engineering

Non-Newtonian Fluid Behavior

H.J.M. Hanley, J.C. Rainwater, M.L. Huber

Collaborators: D.J. Evans (Australian Nat. Univ.), S. Hess (Berlin Tech.

Univ.

)

This program addresses some of the theoretical problems related to the

overall goal of studying complex liquids. The work is carried out in

conjunction with experimental work on neutron scattering and the structure of

liquids and is concerned with the similarities and differences between so- called "simple" (e.g., argon, nitrogen) and "complex" (e.g., polymers, highly

branched hydrocarbons, hydrogen-bonded liquids) fluids. It was largely

motivated by the observation from computer simulation that simple liquids can display rheological or non-Newtonian characteristics usually only associated

with liquids of very complex structure. In this context it is preferable to

classify liquids in terms of a relaxation time of the fluid's microstructure.

Simple liquids have relaxation times of the order of 10'^ s while, for

complex liquids, the time is Is or greater.

There is a connection of this work to the goal of predicting fluid

properties and behavior. Prediction procedures for complex liquids are largely adapted from methods developed for simple liquids, incorporating

improvements in a systematic manner based on an understanding of the

shortcomings of the methods.

32
Specific tasks include: (a) the differences between isobutane and

normal butane have been investigated using computer simulation. These

isomers exhibit polymeric behavior, and the results to date indicate that

isobutane is viscoelastic; (b) work on the rheological characteristics of

simple fluids is continuing with a reexamination of earlier Weissenberg

effect calculations from a reassessment of the importance of shear dilatancv

and finite compressibility; (c) the radial distribution function and

structure factor have been calculated as explicit functions in two

dimensions, and by using an expansion in moments or spherical harmonics in

three dimensions. A technique has been developed to measure the structure

factor of a two-dimensional liquid by transferring the coordinates of the

particles in a model liquid to photographic film, which is then used as a scattering medium for laser light. Statistical noise can be largely removed

by spline - smoothing without changing the three-dimensional structure factor

in the physically important regions. The three-dimensional structure factor

has been compared with those measured in light scattering experiments on sheared colloidal suspensions, and the essential qualitative features of

those experiments are reproduced correctly.

Other recent work includes: (d) study of the effect of shear on the pair

correlation function of a liquid through tensor rank four and derivation and

testing of a theory to predict the correlation function; (e) continued work

on the development of computer programs to simulate liquids under shear and

to show their relationship to experiment; and (f) continued study of an exactly solvable weak potential model under a flow field more general than

planar Couette flow.

DYNAMIC MEASUREMENTS PROGRAM

Thermophysical Measurements by Dynamic Methods

A. Cezairliyan, A.P. Miiller, R.F. Chang, R.A. MacDonald, J.L. McClure,

P.J. Giarratano*, T. Baba (Guest Scientist)

The goal of this program is to develop and utilize techniques capable of

highly accurate measurements of thermal, optical, and electrical properties

of technically important materials at high temperatures using very high

heating rates. Experimental capabilities include millisecond technique? r allow measurements of heat capacity, thermal expansion, electrical

resistivity, phase transition points, and latent heats; microsecond

techniques for measuring thermophysical properties at heating rates of U

10® K/s; and millisecond techniques for such measurements in a microgr.v i

environment. Plans for the immediate future include the development of

dynamic techniques for measurements on nonconducting materials and

theoretical studies relevant to dynamic measurement techniques

Research is under way to develop a system for the measurement < •: thermophysical properties of liquid electrically conducting substnnr-?; v high temperatures (above 2000 K) in a microgravity environment . Kff<u : concentrated in the study of the geometrical stability of the liquid ?;;.>•

33
when heated rapidly by the passage of an electrical current pulse through it

in a microgravity environment. Diagnostic experiments were performed on aircraft operated by NASA. The experiments on board the aircraft were conducted by P. Giarratano. Excursions in the liquid phase could be seen

from the results of the high-speed films and the pyrometric recordings. In

order to improve the geometrical stability of the specimen, a triaxial

configuration for the specimen and the current leads was studied, an experimental chamber was constructed, and experiments were conducted in

aircraft. The results of the experiments with the triaxial configuration

indicate the feasibility of measuring surface tension near the melting point

of the specimen. This new technique will be further explored during the

coming year.

A system for high- temperature thermal diffusivity measurements has

become operational. The system utilizes the laser-pulse technique for

measuring thermal diffusivity of substances at temperatures above 1500 K.

The system was tested for temperatures up to about 2200 K and is capable of

going up to 3000 K. Preliminary measurements on graphite in the range 1500-

2200 K were performed. The results indicated a reproducibility of better

than 1%, which is considered extremely good at these temperatures. The

system can be used for measurements on both conducting and nonconducting

materials

The microsecond- resolution pulse heating system, which became

operational a year ago, was used to conduct feasibility studies on rapid

heating of graphite to high temperatures. The objectives were to reach the

triple point of graphite (about 4500 K) and to investigate the possibility of

excursions in the liquid phase of graphite. The initial results are promising; however, a considerable amount of additional work is required to

attain the objective.

As an integral part of the dynamic measurements program, effort was exerted on the development of rapid temperature measurement techniques. The

research was concentrated on the development of multiwavelength pyrometry as well as spatial - scanning pyrometers. When completed, these will be unique

instruments capable of performing accurate temperature measurements, with

millisecond resolution, either at six wavelengths or over a 2-cm long linear

target

Work has begun in connection with the accurate measurement of thermal

expansion of tungsten above 1500 K and up to near the melting point (about

3700 K) . This work is in connection with the establishment of tungsten as a standard reference material for thermal expansion.

Theoretical studies in support of the Dynamic Measurements Program are continuing in two areas: (1) stability of a liquid cylindrical specimen

under high electromagnetic fields and (2) transient temperature distribution

in a rapidly cooling spherical specimen.

* Chemical Engineering Science Division, NBS/CCE

34
5 . PUBLICATIONS

Albright, P.C., Chen, Z.Y. and Sengers , J.V., Crossover from singular to

regular thermodynamic behavior of fluids in the critical region, Phys

Rev. Lett., Vol. 36, No. 1, pp . 877-880 (July 1987).

Albright, P.C., Edwards, T.J., Chen, Z.Y. and Sengers, J.V., A scaled

fundamental equation for the thermodynamic properties of carbon dioxide

in the critical region, J. Chem. Phys., Vol. 87, No. 3, pp . 1717-1752

(Aug. 1987).

Baltatu, M.E., Olien, N. A. and Hanley, H.J.M., Thermophysical property data

bases, Mech. Eng., in press.

Berg, R.F., Moldover, M.R. and Huang, J.S., Quantitative characterization of

the viscosity of a microemulsion, J. Chem. Phys., Vol. 87, p. 3261

(1987).

Berg, R.F., Moldover, M.R., Rabinovich, S. and Voronel, A., Viscosity and

density of two alkali metal mixtures, J. Phys. F: Metal Phys., Vol. 17,

pp. 1861-1866 (1987).

Bruno, T.J., Catalytic cracking as the basis for a potential detector for gas

chromatography, Nat. Bur. Stand. (U.S.) J. Res., Vol. 92, No. 4,

pp. 261-265 (1987).

Bruno, T.J., Hydrogen component fugacities in binary mixtures with carbon

dioxide: pressure dependence, Int . J. Thermophys . , Vol. 8, No. 2, pp

205-216 (1987).

Bruno, T.J., Indicating rupture disk for gas cylinders, J. Chem. Educ .

Vol. 64, No. 6, p. 557 (1987).

Bruno, T.J., Laboratory applications of the vortex tube, J. Chem. Educ.,

Vol. 64, No. 11, p. 987 (1987).

Bruno, T.J., Physicochemical applications of supercritical fluid

chromatography, Proc . 5th Symp . on Energy Eng. Sci., Argonne Natl. Lab..

CONF- 8706187 , p. 52, June 17-19, 1987.

Bruno, T.J., Solvent free injection in SFC using sintered glass deposition.

Anal. Chem., in press.

Bruno, T.J. and Schroeder, J.A., Hydrogen component fugacities in binary

mixtures with ethane: temperature dependence, Int. J. Thermophys.,

Vol. 8, No. 4, p. 437 (1987).

Calado, J.C.G., Mardolcar, U.V., Nieto de Castro, C.A., Roder, H.M. and

Wakeham, W.A.

,

The thermal conductivity of liquid argon, Physica,

Vol. 143A , pp. 314-325 (1987).

35
Cezairliyan, A., A millisecond- resolution pulse heating system for specific

heat measurements at high temperatures, chapter in book: Compendium of

Thermophysical Property Measurement Methods, Vol. 2, in press.

Cezairliyan, A. and McClure, J.L., A microsecond- resolution transient

technique for measuring heat of fusion of metals: Niobium, Int . J.

Thermophys., Vol. 8, No. 5, pp . 577-592 (1987).

Cezairliyan, A. and McClure, J.L., Heat capacity and electrical resistivity

of liquid niobium near its melting temperature, Int. J. Thermophys., in

press

Chen, L.-J., Ely, J.F. and Mansoori, G.A., Mean density approximation and

hard-sphere expansion theory: a review, Fluid Phase Equilibria,

Vol. 37, pp. 1-27 (1987).

Diller, D.E., Van Poolen, L.J. and Santos, F.V., Measurements of the

viscosities of compressed fluid and liquid carbon dioxide + ethane

mixtures, J. Chem. Eng. Data., in press.

Eaton, B.E., Analysis of laminar vortex shedding behind a circular cylinder

by computer-aided flow visualization, J. Fluid Mech., Vol. 180,

pp. 117-145 (1987).

Erickson, D.D., Leland, T.W. and Ely, J.F., A method for improving equations

of state near the critical point, Fluid Phase Equilibria, Vol. 37,

pp. 185-205 (1987).

Evans, D.J. and Ely, J.F., Viscous flow in the stress ensemble, Mol. Phys .

,

Vol. 59, p. 1043 (1986).

Evans, D.J., Hanley, H.J.M. and Hess, S., Non-Newtonian Fluid Behavior,

section in book: Fizika za. Rubezhom 1986A, p.7, Moscow (1986).

Flanigan, D.A, Yesavage , V.F., Cerise, K. and Niesen, V.G., Enthalpy of

quinoline between 291 and 650 K and pressures up to 10342 kPa, J. Chem.

Thermodynamics, in press.

Flanigan, J.W., Development of a calorimetric facility for measuring excess enthalpies at temperatures of 20 to 80°C and at atmospheric pressure,

M.S. Thesis, Colorado School of Mines, Golden, CO (May 1987).

Fox, J.R., Development of a field space corresponding states method for

fluids and fluid mixtures, Fluid Phase Equilibria, Vol. 37, pp . 123-140

(1987)

Friend, D.G. and Roder, H.M., The thermal conductivity surface for mixtures

of methane and ethane, Int. J. Thermophys., Vol. 8, No. 1, pp . 13-26

(Jan. 1987).

36
Gallagher, J.S., Linsky, D., Morrison, G. and Levelt Sengers , J.M.H.,

Thermodynamic properties of a geothermal working fluid - 90% isobutane

10% isopentane, Nat. Bur. Stand. (U.S.) Tech. Note 1234 (June 1987).

Hamad, E.Z., Mansoori, G . A. and Ely, J.F., Conformality in the Kirkwood-Buff

theory of statistical mechanics, J. Chem. Phys . , Vol. 86, No. 3,

pp. 1478-1484 (Feb. 1987).

Hanley, H.J.M., Perspectives in nonequilibrium molecular dynamics, section in

book: Molecular Dynamics Simulations of Statistical Mechanical Systems,

p. 17, Ed. by C. Ciccotti and W. Hoover, North Holland, NY (1986).

Hanley, H.J.M., Morriss, G.P., Welberry, T.R. and Evans, D.J., Shear- induced

anisotropy in two-dimensional liquids, Physica, in press.

Hanley, H.J.M., Rainwater, J.C. and Hess, S., Shear- induced angular

dependence of the liquid pair correlation function, Phys. Rev.,

Vol. A36, No. 4, pp. 1795-1802 (1987).

Hanley, H.J.M., Straty, G.C., Glinka, C.J. and Hayter , J.B., Low-Q neutron

diffraction from supercooled D-glycerol, J. Mol. Phys., Vol. 60 (1987).

Haynes, W.M. , Diller, D.E. and Roder, H.M., Transport properties of fluids of

cryogenic interest, Cryogenics, Vol. 27, pp . 348-360 (July 1987).

Haynes, W.M. and McCarty, R.D., Comprehensive study of methane + ethane

system, Proc . of Int . Symp . on Fluid Flow Measurement, Wash., DC, Nov.

16-19, 1986.

Hubbard, J.B., Dynamic processes in liquids and selected topics related to

the dynamics of ions and electrons in liquids, chapter in book: N.A.T.O.

Advanced Study Institute Proceedings, The Liquid State and Its

Electrical Properties, Ed. by E. Kunhardt, L. Luessen and L. Christophorou, in press.

Hubbard, J.B., Non-equilibrium theories of electrolyte solutions, chapter in

book: N.A.T.O. Advanced Study Institute Proceedings, The Physics and

Chemistry of Aqueous Ionic Solutions, Ed. by G. Neilson and M.C.

Bellissent-Funel , pp . 95-128 (1987).

Hubbard, J.B. and McCammon, J.A., Electrophoretic light scattering from

macromolecular solutions and conformational dynamics, J. Chem. Phys.

press

Huber, M.L. and Ely, J.F., Development of an improved conformal solution

theory for mixtures with large size ratios, Fluid Phase Equilibria,

Vol. 37, pp. 105-121 (1987).

Huber, M.L. and Jones, M.C., A frequency response study of packed b. <1 !.-• >• transfer at elevated temperatures, J. of Heat and Mass Transfer,

press

37
Jacobsen, R.T., Stewart, R.B., Penoncello, S.G. and McCarty, R.D., An interim

thermodynamic property formulation for air, Fluid Phase Equilibria,

Vol . 37, pp. 169-184 (1987)

Kayser, R.F., Wetting layers in electrolyte solutions, J. de Physique, in

press

Kayser, R.F., Wetting layers on solid substrates, KINAM (Mexico), in press.

Kayser, R.F., Moldover, M.R. and Schmidt, J.W., What controls the thicknesses

of wetting layers?, J. Chem. Soc . , Faraday Trans. 2, Vol. 82, p. 1701

(1986)

Kincaid, J.M., MacDonald, R.A. and Morrison, G., A thermodynamic perturbation

theory for multicomponent and polydisperse mixtures, J. Chem. Phys . , in

press

Lee, S.H., Rasaiah, J.C. and Hubbard, J.B., Molecular dynamics study of a dipolar fluid between charged plates II, J. Chem. Phys., Vol. 86,

p. 2383 (1987).

Linsky, D., Levelt Sengers , J.M.H. and Davis, H.A., Semi - automated Burnett

PVT apparatus - properties of a geothermal working fluid, Proc . 5th

Symp. on Energy Engr . Sci., Argonne Natl. Lab., CONF- 8706187 , pp . 26-36,

June 17-19, 1987.

Linsky, D., Levelt Sengers, J.M.H. and Gallagher, J.S., A semi -automated

Burnett facility, PVT of a geothermal working fluid mixture, Proc. of

Experimental Thermodynamics, Transport Phenomena and Chromatography II,

AIChE (1987).

MacDonald, R.A. , Callanan, J.E. and McDermott, K.M. , Heat capacity of a medium volatile bituminous premium coal from 300-520 K - comparison with

a high volatile bituminous nonpremium coal, Energy & Fuels, Vol. 1 (Nov. 1987)

Marchi, M. and Mountain, R.D., Thermal expansion of a structure II hydrate

using constant pressure molecular dynamics, J. Chem. Phys., Vol. 86,

No. 11, pp. 6454-6455 (1987).

McCarty, R.D., Speed of sound in natural gas mixtures, Proc. of Int . Symp. on Fluid Flow Measurement, Wash., DC, Nov. 16-19, 1986.

Miiller, A.P. and Cezairliyan, A., Thermal expansion of niobium in the range

1500-2700 K by a transient interferometric technique, Int. J.

Thermophys . , in press.

Moldover, M.R., Low-gravity experiments in critical phenomena, Chapter 2B in

book: Opportunities for Academic Research in a Low-Gravity Environment,

Ed. by G. Hazellrigg and J. Reynolds, Vol. 108, American Inst, of Aero,

and Astro., Inc., NY (1987).

38
Moldover , M.R. and Rainwater , J.C., Interfacial tension and vapor- liquid

equilibria in the critical region of mixtures, J. Chem. Phys., in press.

holdover , M . R .

,

Trusler , J . P . M .

,

Edwards , T . J .

,

Mehl , J . B

and Davis , R . S .

Measurement of the universal gas constant using a spherical acoustic

resonator, Proc. of the 3rd IMEKO Symp . on Thermal and Temp. Measurement

in Sci. and Ind. , Sheffield, England, Sept. 15-17, 1987.

Moldover, M.R., Trusler, J.P.M., Edwards, T.J., Mehl, J.B. and Davis , R.5.,

Measurement of the universal gas constant R using a spherical acoustic

resonator, Nat. Bur. Stand. (U.S.) J. Res., in press

Shorter version

submitted to Phys. Rev. Lett.

Morrison, G. and McLinden, M.O., Application of the Carnahan- StarlingDeSantis equation of state to mixtures of refrigerants, Transactions of

ASME , in press

Mountain, R.D. and Basu, P.K., Molecular dynamics evaluation of cell models

for type I gas hydrate crystal dynamics, J. Phys. Chem. Solids, in

press

Mountain, R.D. and Morrison, G., Molecular dynamics study of liquid CCI 2 F2 and CCIHF2 , Mol. Phys., in press.

Mountain, R.D. and Thirumalai , D., Molecular dynamics study of glassy and

supercooled states of a binary mixture of soft spheres, Phys. Rev. A, in

press

Niesen, V.G., Palavra, A., Kidnay, A.J. and Yesavage, V.F., An apparatus for

vapor- liquid equilibrium at elevated temperatures and pressures and

selected results for the water-ethanol and methanol -ethanol systems,

Fluid Phase Equilibria, Vol. 31, pp . 283-298 (1986).

Niesen, V.G. and Yesavage, V.F., Vapor-liquid equilibria for m-cresol/

quinoline at temperatures between 523 and 598 K, J. Chem. Eng. Data, in

press

Niesen, V.G. and Yesavage, V.F., Vapor-liquid equilibria for m-cresol/

tetralin and tetralin/quinoline at temperatures between 523 and 598 K. J. Chem. Eng. Data, in press.

Nieto de Castro, C.A., The measurement of transport properties of fluids - A

critical appraisal, 1987 ASME-JSME Thermal Eng. Joint Conf., Honolulu.

HI, p. 327, March 22-27, 1987.

Nieto de Castro, C.A., Taxis, B., Roder, H.M. and Wakeham, W.A., Thermal

diffusivity measurements by the transient hot wire technique: A

reappraisal, Int . J. Thermophys . , in press.

Olien, N.A. , Thermophysical properties for bioprocess engineering,

Progress, Vol. 83, No. 10, pp . 45-48 (Oct. 1987).

39
Pegg, I.L. and Morrison, G., Phase behavior of pentadecanoic acid monolayers

using a new wide range automated film balance, Rev. Sci. Instr., in

press

Rainwater, J.C. and Friend, D.G., The second viscosity and thermal

conductivity virial coefficients of gases: Extension to low reduced

temperature, Phys . Rev., Vol. A36, No. 8, pp . 4062-4066 (Oct. 1987).

Rainwater, J.C., Hanley, H.J.M. and Hess, S., The static structure factor of

a soft sphere liquid under shear, Phys. Lett. A, in press.

Rainwater, J.C. and Jacobsen, R.T., Vapor-liquid equilibrium of nitrogenoxygen mixtures and air at high pressure, Cryogenics, in press.

Roder, H.M., A high temperature thermal conductivity apparatus for fluids,

Proc. 5th Symp . on Energy Engr. Sci., Argonne Natl. Lab., CONF- 8706187

pp. 61-68, June 17-19, 1987.

Roder, H.M. and Nieto de Castro, C.A., The heat capacity, Cp , of fluids from

transient hot wire measurements, Cryogenics, Vol. 27, pp . 312-313

(June 1987)

Roder, H.M., Nieto de Castro, C.A. and Mardolcar, U.V., The thermal

conductivity of liquid argon for temperatures between 110 and 140 K with

pressures to 70 MPa, Int . J. Thermophys . , Vol. 8, No. 5, pp . 521-540

(Sept. 1987).

Schmidt, J.W., The structure of a fluid interface near the critical point,

Phys. Rev. Lett., submitted.

Schmidt, J.W., Systematics of wetting and prewetting, J. Colloid Interface

Sci .

,

submitted

Schmidt, J.W. and Guzman, F., On the surface properties of the mixture water

+ phenol, J. Phys. Chem. , Vol. 91, p. 263 (1987).

Stiles, P.J., Kagan, M. and Hubbard, J.B., Frictional torque on a sphere

rotating in a uniformly magnetized ferrofluid, J. Colloid Interface

Sci., Vol. 117, No. 2, p. 591 (1987).

Stiles, P.J., Kagan, M. and Hubbard, J.B., On the Couette -Taylor instability

in ferrohydrodynamics , J. Colloid Interface Sci., in press.

Straty, G.C., Ball, M.J. and Bruno, T.J., PVT of toluene at temperatures to

673 K, J. Chem. Eng. Data., in press.

Straty, G.C., Ball, M.J. and Bruno, T.J., PVT properties of benzene at

temperatures to 723 K, J. Chem. Eng. Data, Vol. 32, p. 133 (1987).

Sullivan, F. and Mountain, R.D., Ising spin exchange simulations on the MPP,

Proc. of 6th Int. Phoenix Conf. on Computers & Comm., Scottsdale, AZ

pp . 74-78 (Nov. 1986).

40
Van Poolen, L.J. and Rainwater, J.C., Determination of binary mixture

vapor-liquid critical densities from coexisting density data., Int. J.

Thermophys., Vol. 8, No. 6, pp . 695-715 (1987).

Woolley, H.W., Ideal gas thermodynamic functions for water, Nat. Bur. Stand.

(U.S.) J. Res., Vol. 92, No. 1, p. 35 (1987).

Yesavage, V.F., Niesen, V.G., Flanigan, D . A. andKidnay, A.J., Enthalpy of

ternary mixtures of m-cresol/1-methylnaphthalene/trans-decalin between

291 and 650 K at pressures of 207, 690, and 10342 kPa, J. Chem. Eng.

Data, Vol. 32, pp . 323-327 (1987).

Yesavage, V.F., Niesen, V.G., Flanigan, D.A., Sandarusi, J.A. and Flanigan,

J., Enthalpy of ternary mixtures of quinoline/1 -me thylnaphthalene/trans

decalin and enthalpy of quaternary mixtures of m-cresol/quinoline/1-

me thylnaphthalene/trans -decalin between 291 and 650 K and at pressures

of 207 and 10342 kPa, J. Chem. Eng. Data, in press.

Younglove, B.A. and Ely, J.F., Thermophysical properties of fluids, II,

Methane, Ethane, Propane, Isobutane and Normal Butane, J. Phys . Chem.

Ref. Data., in press.

Younglove, B.A. and Hanley, H.J.M., Transport properties of argon, J. Phys.

Chem. Ref. Data, Vol. 15, p. 1323 (1986).

6. CONFERENCES AND WORKSHOPS

CONFERENCES

A Symposium consisting of four sessions and twenty- two papers in honor of

Thomas W. Leland, 1987 Spring National Meeting of AIChE, Houston, TX.

Organized and chaired by James Ely.

A Symposium on Thermodynamics for Bioseparations, November 1987 AIChE

National Meeting, New York, NY. Organized and chaired by Professor Carol

Hall, Department of Chemical Engineering, North Carolina State University,

Raleigh, NC and Neil Olien.

WORKSHOPS

Working Group A, International Association for Properties of Steam, held .it Reading, UK, Sept. 13-18, 1987. Chaired by J.M.H. Levelt Sengers , who 1

>

.

< • coorganized a one-day workshop on Solutions in High-Pressure Steam and !!

: Temperature Water.

Workshop on Thermophysical Properties for Bioprocess Engineering,

Gaithersburg, MD, March 16, 1987. Organized and chaired by Neil Olien.

Report of Meeting published in Chemical Engineering Progress . Vol

Hi,

45-48 (Oct. 1987).

41
TECHNICAL ACTIVITIES

OF THE

CHEMICAL PROCESS METROLOGY DIVISION

H.G. Semerjian, Chief

1. INTRODUCTION

The research of the Chemical Process Metrology Division is focussed on

the development of new measurement techniques for process sensing,

diagnostics and control. Particular emphasis is placed on measurement

methods and data that are needed for process control in the chemical,

biochemical, and related industries.

The approach has been to conduct research on new experimental methods

and engineering science underlying reliable measurements and data bases; this

work is complemented with theoretical and computational modeling of processes

under investigation and transport processes affecting sensor performance.

The research is aimed at a) investigation of new engineering and scientific

principles which can be used for measurement of physical or chemical

quantities in industrial processes, b) development of accurate measurement

methods and measurement standards for industry, and c) providing primary

calibration services for a wide segment of U.S. industry and the scientific

research community. These measurements include temperature, pressure,

velocity, flow rate, humidity, composition and concentration, pH, particle

size and number density, volume fraction and other quantities of interest in

multiphase reacting and non-reacting process streams. Emphasis is on the

development of on-line, and where possible in- situ, measurement techniques

needed for control of industrial processes

Current projects address several of the research areas mentioned above.

An extensive data base has been developed on orifice discharge coefficients

to improve the accuracy of flow metering in gaseous and liquid streams. This

work represents a major contribution towards equity in the domestic and

international trade of oil and gas, as well as other commodities. Other

projects on vortex shedding flowmeters and installation effects (supported by

industrial consortia) have also resulted in experimental data critically

needed for improvement of the current flowrate measurement technology.

Electromagnetic field methods have been successfully applied for measurement

of solids fraction in slurry flows, and a prototype sensor is currently

undergoing field tests. Electrochemical techniques have also been used for

measurement of diffusion coefficients in liquids, and are now being extended

to porous media. Optical techniques have been developed, particularly for

measurements in single phase and multiphase reacting flows. They have been

successfully applied to provide data on temperature, gas composition,

particle size distribution and gas/solid reaction rates in flames, fluidized

beds, plug flow reactors and other high temperature reacting flows. Solidstate sensors, utilizing iridium oxide and tin oxide, are being developed for

pH and chemical composition measurements in process streams. Thin film

thermocouples have been demonstrated to provide temperature measurements in

42
harsh environments (e.g. in ceramic engines) with good temporal resolution.

Finally, computational models have been developed to simulate chemically

reacting flows, formation and oxidation of particles, and transport processes

in high temperature reacting flows.

Future trends in the Chemical Process Industry are directed toward

transition to higher-value added products, increased biochemical production

of pharmaceuticals, foodstuffs, specialty chemicals and fuels, and increased

production of chemicals and materials for microelectronics, photonics and

high temperature applications. The Division's programs are being developed

to address many of the critical technical problem areas and measurement needs

within these emerging technologies . Several new and exciting projects are underway to provide new measurement methods for biochemical reactors - - optical diagnostic techniques have been demonstrated as useful tools for

substrate, product and cell concentration measurements in fermentation

systems; an electrophoretic light scattering technique is being developed as

a new tool to monitor protein separation processes; magnetic resonance

techniques are expected to provide critically needed data on compositional

distribution and transport rates in bioreactors. Techniques developed for

particulate measurements in flames are being extended to study formation of

silica particles, in order to provide data needed to improve chemical

processes used in the fabrication of optical fibers . Laser diagnostic

techniques, used for temperature and gas phase composition measurements in

flames, will be extended to study chemical vapor deposition, laser enhanced

CVD , plasma etching and other processes used in microelectronics fabrication.

Laser based diagnostic techniques are also expected to make a significant

contribution toward optimization of powder atomization processes , one of the

most promising processes in metals processing and for production of high

temperature ceramics . Finally, currently available high temperature reacto:'

facilities (FBR, PFR) are being modified to study pyrolysis and combustion

chlorinated hydrocarbons. This project will provide critically needed dat

to address a major national concern - disposal of hazardous wastes . Developments in these emerging areas of research will be closely monitored,

and the Division's research priorities will be modified to meet anticipated

measurement and data needs

The Division has been striving to develop and maintain all possible

forms of technology transfer. Industrial consortia have been one of th<

successful forms of this transfer and the Flowmeter Installation Effects

Consortium has attracted a substantial membership. The results are repm "

i in the main body of this report.

The Division has continued providing calibration services in mass and

volumetric flow, air speed, humidity, volume and liquid density to i ndu«. •

: : and public clients across the country. The recent upgrading of these

facilities will make it possible to serve U.S. industry even better.

43
2 . GOAL

Within the framework of the Center for Chemical Engineering, the

Division's main concern is the science of measurement in homogeneous and

heterogeneous flow systems with and without chemical reaction.

The goal of the Division is to provide the chemical and related

industries and other government agencies with the measurement techniques,

fundamental data, and the underlying scientific principles pertinent to

homogeneous and heterogeneous flows with and without chemical/biochemical

reactions at ambient and elevated temperatures. A key element in the pursuit

of this goal is the study of surface, transport, and kinetic phenomena in the

environment of sensing and diagnostic tools.

It is further recognized that process measurement is the key component

of any process control loop, the proper function of which is essential to

maintaining the highest quality of manufactured goods and, in turn, the

competitive edge of U.S. industry in domestic as well as foreign markets.

Parallel with its research work, the Division maintains state-of-the-art

calibration services for flow, volume, density, humidity and air speed, thus

providing industry and other government agencies with traceability of their

instrumentation to national standards and assuring equity in domestic and

international trade.

3. GROUP FUNCTIONS

The research activities of the Division are performed within four

groups

o Fluid Flow Group - G.E. Mattingly, Group Leader

The mission of the Fluid Flow Group is to study the fundamentals of

fluid flow with the aim of advancing the state-of-the-art in flow

metrology and applying these principles toward improving and expanding

the NBS flow measurement capabilities, as needed, for single phase gases

and liquids (water and hydrocarbons) and multiphase systems (sand-water

mixtures)

Research is primarily focused on flow phenomena in confined flows as well as in free surface flows in geometries pertinent to the

technologies used in the chemical and related industries.

The Fluid Flow Group maintains responsibility for the NBS fluid flow

rate and airspeed calibration services and for the maintenance and

upgrading of the relevant national standards. The Group is responsible

for the transfer of fluid flow measurement technology to industry, other

government agencies, and to public institutions.

44
° Multiphase Reacting Flows Group - A.K. Gaigalas , Group Leader

The mission of the Multiphase Reacting Flows Group is to perform

research on multiphase flows at ambient and near-ambient temperatures

with and without chemical reactions. The ultimate purposes of this

activity are to (1) provide fundamental data, (2) develop improved

measurement techniques for on-line process diagnostics, and (3) develop

mathematical models for improved understanding and control of physical,

chemical, and biochemical processes.

Particular emphasis is placed on the development of advanced diagnostic

techniques utilizing electromagnetic and acoustic fields and

electrochemical phenomena.

The Multiphase Reacting Flows Group bears the responsibility for NBS

calibration services in liquid density and volume.

° High Temperature Reacting Flows Group - A. Macek, Group Leader

The High Temperature Reacting Flows Group conducts fundamental research

on chemically reacting flows, especially those with gas -solid reactions

involving solid particles either formed or entrained. The research

includes advanced non- intrusive optical measurement techniques for high

temperature reactors such as combustors and fluidized bed reactors.

Particular emphasis is on the use of laser scattering and extinction

techniques for particle characterization, laser tomography for

temperature and composition measurement, laser induced fluorescence

(LIF) , and emission spectroscopy for temperature measurement. The

scattering/extinction techniques are being adapted to the study of gassolid chemical reactions relevant to chemical vapor deposition, and to

ceramics and powder metallurgy.

A significant segment of the research activities in this group is the

extension of the LIF techniques to optical diagnostics of species

(nutrients, substrates, metabolic intermediates, and products) in

biochemical reactors. Some of the research in this group will be

assigned to the Optical Diagnostics Group, in the Center Office, in

fiscal year 1988.

° Process Sensing Group - K.G. Kreider, Group Leader

The Process Sensing Group performs research directed toward the

development of process sensors with particular emphasis on solid star.- sensors for chemical species, humidity and temperature. Reactivesputtering is used to form films and a comprehensive surface anal-.- -

: facility is used to characterize the surfaces of these films where th<

chemical reaction takes place.

45
For gas sensing, the focus of the research is on tin oxide films while

iridium oxide forms the backbone of the work on ionic sensors. Further,

thin film thermocouples deposited on metal, ceramic and polymer

substrates are subjects of study.

A study to develop optimum and standardized methods for collection of

samples of water, air, and soil is an integral part of the research

effort in this group.

The Process Sensing Group is responsible for providing the NBS

calibration services for humidity and for the maintenance of the

humidity national standard.

4. SELECTED PROJECT SUMMARIES

CALIBRATION SERVICES

Calibration and Test Services Performed

by the Chemical Process Metrology Division

G.E. Mattingly, A.K. Gaigalas , K.G. Kreider

In the past year, the CCE calibration services have satisfied industry

and government requests for a number of metrological tasks in the areas of

fluid flowrate, liquid density and volume, air speed, and humidity

measurements. Additionally, the techniques and facilities for performing

these services have been assessed and are being upgraded so that the levels

of measurement uncertainty are quantified and reported for publication in the

appropriate literature. In the specific calibration services offered to U.S.

industry, activities are summarized as follows:

Service Number of Items Calibrated

Flowrate

Volumetric Containers

Aerodynamic Devices

Reference Standard Hydrometers

Humidity

58 (40 for industry)

88 (81 for industry)

85 (59 for industry)

73 (73 for industry)

81 (78 for industry)

These calibrations generally establish a traceability link between the

respective calibration requester and NBS. In this way, these calibrations

form a basis for the assurance of all measurements produced in the

requester's laboratories.

Besides these services, a number of in-situ calibrations were performed

by NBS personnel in the customers' laboratories. In this way, improved

measurement assurance was provided to strengthen the traceability links

between actual, installed instrumentation and the national standards for

these measurements.

46
FLUID FLOW GROUP

Round-Robin Flow Measurement Assurance Program

G.E. Mattingly

In the last year, the Fluid Flow Group has continued the DoD-requested

program to conduct a round- robin flow measurement assurance program to check

flowmeter calibration facility performances in Army, Navy, and Air Force

labs. This program, requested for hydrocarbon liquids, has been designed for

several sets of tandem turbine meters. Specific test procedures are being

used in the DoD labs to quantify lab performances to make satisfactory flow

measurements. This program will be used on a continuing basis to maintain

desired control of these measurement processes. At the request of these DoD

labs, this testing program is being expanded to include industrial

laboratories. In this manner, realistic flow measurement traceability will

be established and maintained for the participating laboratories.

Also, in the last year, the Fluid Flow Group has responded to a Navy

request to assess the flowrate measurement accuracy of a Navy selected

flowmeter calibration facility. The results of this project will be twofold: (1) to produce a quantified evaluation of the facility's performance

in actual dynamic conditions of use, and (2) to provide direct traceabil i tv

to NBS flow standards for this facility.

Flowmeter Ins tallation- Effects Consortium Research

G.E. Mattingly, T.T. Yeh

The NBS flowmeter research program on installation- effects continues to

attract participation of industry through a consortium that has been formed

to assist in supporting this program. Benefits to consortium participants

include guiding current and future phases of the work and receiving results

on a timely basis. The consortium currently includes some 15 meter

manufacturers and users, U.S. and foreign. Research results will provide,

for the first time, qualitative and quantitative descriptions of the

distorted pipeflows produced by piping configurations. These results art- used to upgrade or to initiate useful installation specifications for

flowmetering standards by implementing a new strategy to achieve this ro.h

The strategy adopted for this program contrasts markedly with that i in the past. Conventionally, it has been the practice to conduct

considerable numbers of specific meter calibrations to determine the mi: : al distances (between meter and specific upstream piping configuration' f

>• r which uncertainty levels on meter factors are to be increased hv :

• : : : amounts. Through this conventional approach, little was learned or understood of the salient features of the pipeflow profiles involv. ! currently adopted strategy focuses on these profiles; specifically, i: measures them using Laser Doppler Velocimetry (LDV) , and charar •

. r i and their changes with distance from the piping configuration.

47
With these results, and the associated understanding of these pipeflows,

a number of limited, informed calibration tests can be carried out by meter

manufacturers and others so that specific results, i.e., discharge

coefficients, meter factors, etc., are related to pertinent pipeflow

characteristics. In this way, meters can be installed in any locations where

their performance is satisfactorily stable, and meter factors or discharge

coefficients are satisfactorily predicted for the installation. It is

expected that this strategy will produce installation specifications for

metering standards which will enable satisfactory flow measurements to be

made in installations previously considered non- ideal and for which no current standards are applicable.

In the past year, extensive LDV profiling has been done in two- inch (50

mm) diameter, cylindrical pipeline water flows. Results for diametral

Reynolds numbers of 10^ and 10^, and a relative roughness of 0.0005, show

that the second elbow-out-of-plane configuration generates severe and complex

swirl. This second elbow arrangement has a short (2.4D) length of straight

pipe placed between the elbows . This short length of pipe produces

considerable changes in the outflow compared to the closely coupled elbows

tested previously.

As was done with the previous configuration using different types of

flowmeters (a turbine and three sizes of orifice meter) , the methodology of our research was demonstrated. The level of success varied for the different

types of flowmeter.

It is concluded that this strategy for producing improved flowmeter

installation specifications can be very effective. The current phase of this

research continues to produce analogous results for the single elbow piping

configuration so ubiquitous in actual metering practice and so disruptive of

meter performance. It is also concluded that results of this program can be

very useful in designing and installing efficient flow conditioners for

reducing or eliminating such anomalous pipeflows.

High Pressure Inert Gas Atomization

G.E. Mattingly, P.I. Espina

Metal atomization- -the production of fine powders through the

interactions of high pressure gas jets and liquid metal streams --is an emerging technology that offers considerable promise for industrial

productivity in the metallurgical industries. To assist U.S. industry in

this area, the NBS Office of Non-Destructive Evaluation (NDE) has formed an industry- government consortium to produce and demonstrate the measurement

methods needed to automate and optimize the productivity of this process. To

attain this objective an NBS team has been formed which brings together four

different capabilities - -metallurgy , fluid flow, optical particle measurement,

and automation.

48
In the past year, the Fluid Flow Group has conducted a range of

experiments on gas -liquid interactions. The strategy is to begin with the

gas-only flow field and determine the characteristics of this flow as conditions are changed toward the harsh, hostile pressures and temperatures

used in the actual process. These tests have involved a range of measurement

methods which have focused on the velocity and pressure distributions in the

gas -liquid interaction zones. The salient features of these flowfields are then correlated with pertinent parameters.

Our efforts continue to generate measurement techniques capable of

sensing critical flow features. These sensors will then provide input for

other sensors or for automated control so that the desired powder product is

made. This project is viewed as a continuing one in which a wide range of

conditions - -metal alloys, powder sizes, geometrical arrangements of gasliquid interactions, stimulation techniques, ultrasonics, etc. --can be tested

to determine effects upon the process productivity.

Vortex Shedding Flowmeter Research

G.E. Mattingly, T.T. Yeh

The industry- government consortium sponsored project on vortex shedding

flowmeter performance successfully completed its two year effort to

characterize "jitter" and "fade" effects. The final report of the

experiments has been sent to the sponsors (14 vortex meter manufacturers and

users) . With the final report was sent a survey questionnaire to suggest

topics for a follow-on second phase of this program and to indicate industry

interest in continuing research.

MULTIPHASE REACTING FLOWS GROUP

Measurement of the Solids Fraction in Two -phase Flows

W.G. Cleveland, A.K. Gaigalas

A technique has been developed to measure the fraction of solids

suspended in a flowing water-based slurry. It is assumed that the slurrv i flowing in a conducting pipe which can act as a waveguide for radio waves

By measuring the speed of radio waves propagating in the flowing slurry

by comparing the measured speed to the value for pure water, it is possible

to infer the amount of solid material carried by the water stream. Test:; <: the meter in the laboratory have demonstrated a high degree of accuracv

Attempts to adapt the meter to the factory environment are in progress,

major problem is the high conductivity of the process stream and the

necessity to use non- intrusive antennas.

The operation of the meter has been investigated in solutions vi'i.

sodium sulfate concentration up to 10 mM. The major contribution of r :

. conductivity to the value of the extracted dielectric constant was as required by Maxwell's equations. Small discrepancies between : hi- . ;

• • e<

49
and measured dielectric constant were most likely due to the nature of the

parameter fitting algorithm. The small instability in the convergence of the

algorithm is under investigation. It was also found that the addition of a small amount of the second mode improved the correspondence between the

expected and measured response of the detector array.

The conductivity studies were performed with an intrusive antenna

consisting of a loop in the middle of the pipe with its plane aligned with

the axis of the pipe. Further effort is being made to make the antenna less

intrusive and thus acceptable to the factory environment.

Electrophoretic Light Scattering (ELS')

S. Woo, A.K. Gaigalas, J.J. Ulbrecht

The object of this study is to develop a technique to monitor the

protein separation process. It is well established that gel electrophoresis

can be used to identify a variety of proteins. The technique is based on the

differences in protein response to electric fields. ELS also utilizes the

variability of the surface charge of proteins to detect differences in

electrophoretic velocity. The major difference is that ELS occurs in-situ

and is orders of magnitude faster then the gel method.

The initial effort consisted of setting up the apparatus for measurement

of diffusion of latex spheres in solutions of different ionic strength. This

effort has resulted in a working system which can measure the diffusion of

latex particles using photon correlation techniques. The initial measurement

of the change of diffusion coefficient with changing ionic strength has been

successful. Besides its intrinsic merit, this measurement serves as a foundation for extending the work to electric field effects. Another effort

in that direction has been the measurement of diffusion in low molecular

weight acrilamide solutions. These solutions can support large electric

fields and thus will be very useful for the initial ELS measurements . At

this time two sets of ELS scattering cells are being developed.

Electrochemical Study of Mass Transfer in Porous Media

B. Robertson, A. Van Orden, A.K. Gaigalas

A project has been initiated to measure, as a function of frequency, the

ac electrochemical impedance of a porous medium saturated with an aqueous

salt solution. The impedance at low frequencies depends on the mass transport of the ions, which is governed by adsorption of the ions onto the

surface of the pores and by diffusion of the ions both in the liquid and on

the surface. The low-frequency measurements give much more information about mass transport than the usual measurement of the high-frequency electrical

conductivity of the saturated porous medium. These measurements will be

related to the results of magnetic resonance imaging measurements.

50
Electrochemical Measurement of Diffusion Coefficients

B. Robertson

The electrohydrodynamic (EHD) method of measuring the Schmidt number has

been compared carefully with the older dc method of Levich using a rotating

disk electrode. With the EHD method, the speed of rotation of the disk is

modulated sinusoidally, and the resulting sinusoidal variation of the

limiting current is measured. The advantage of the EHD method is that it

does not require measuring the area of the electrode, the number of electrons

transferred, or the concentration of the limiting reactant, as does the dc

method. The two methods agree within 1 per cent when the EHD measurement is

done at a low disk velocity. A knowledge of the diffusion coefficient in the

pure liquid is necessary for studying the effect of a porous media on mass

transfer. This work has been done in collaboration with B. Tribollet and C. Deslouis of the University of Pierre and Marie Curie in Paris.

Studies of Flow in the Vicinity of a Mixer Blade

R.C. Calabrese, B.J. Sadoff

A liquid- liquid drop dispersion flow loop facility has been used, in

collaboration with the University of Maryland, to study flow in the vicinity

of sharp-edged bodies which simulate real mixing elements. The facility uses laser velocimetry, high speed photography, and hydrogen-bubble techniques to

characterize flow fields. The experimental work has led to the following

conclusions. Trailing vortices extend to about 2 blade widths beyond the

point of formation. The turbulent kinetic energy peaks at about one blade

width beyond the tip, and it is highest on the outer edges of the vortices.

In the vortex, the magnitude of the rms turbulent velocity is greater than

that of the mean. At the blade tip, mean deformation rates on the vortex

edge are about 100 times the impeller speed, peaking at about 190. These

values become more uniform and decrease with distance from the point of

vortex breakdown. The mean velocity field is equally rotational and

deformational . At the blade tip, about 10% of the energy dissipated is du<

to mean gradients. The viscous contribution decreases rapidly to about 1*.

On the vortex outer edges, energy dissipation rates can be one to two order

of magnitude greater than the mean for an equivalent stirred tank. The peak

value in the channel is about 250 times the mean.

Corrosion of Nuclear Waste Containers

A. Van Orden

Nuclear waste containers are designed to last for approximately ICimm

years. The design material for these containers in two of the planned

repository locations is A-216 carbon steel. Since there are no data fni a or any other alloy under repository conditions for hundreds or thousand',

years, this project seeks to use ancient metals as analogues for these

containers. The abundance of metal archaeological artifacts found

51
conditions makes it possible to use these to test mathematical models and

draw general conclusions about the very long term corrosion behavior and

stability of modern iron objects. Nails and their surrounding soil were obtained for study from near Dorchester, which is a site of known Roman

occupation. These artifacts, with their corrosion film coatings, have been

examined using scanning electron microscopy, energy dispersive x-ray

analysis, microprobe analysis, x-ray diffraction and Mossbauer spectroscopy

to provide information on the composition of both the remaining metal and the

corrosion film. These data can be compared with the theoretical models for

corrosion of iron and may help in validation of these models. The chemistry

of the soil, and the ground water interactions, are also being studied to

provide information on the transport of metal ions away from the corroding

interface and on transport of oxygen and other reactive species to the

interface. The nature of the corrosive attack is being studied to evaluate

parameters in the existing models such as localized attack.

Early results show that the corrosion film is composed of Fe 203 , FejO^.,

and non- stoichiometric FeO. The corrosion film has several layers, the

origin of which is not yet known. There is also evidence of extensive

localized corrosion, which must be considered in any model used to describe

the development of oxides on low carbon steel. The microstructure of the

nail itself gives data on the manufacturing techniques used at this time. By

considering how the nails were made, information on subjects of modern

interest such as decarburization of the surface is being obtained. Data from

the analyses of the corrosion film and soil are being compared to short-term

data on the corrosion of modern alloys. In addition to the experimental

results, a database has been established for ancient metal artifacts with a particular emphasis on transport of metallic ions, in porous materials, over very long periods of time.

Application of Magnetic Resonance Imaging (MRI) Techniques to the

Study of Mass Transfer in Porous Media

A. Van Orden, B. Robertson, A.K. Gaigalas

The flow of water in porous materials was visualized by using magnetic

resonance imaging (MRI). For initially dry beds, the water gives a large

signal that can be detected directly. For flow in a wet bed, a dilute

solution of manganese ions in water was used to displace the pure water and

quench the MRI signal. Thus, the flow could be visualized indirectly. For

materials such as bentonite, which interact strongly with water, the MRI

technique also shows the interface region in which the water-bentonite

complex is formed. The technique is sensitive and can give accurate and

quantitative results for flow with low Peclet number.

For the initial experiment, four materials were chosen to give a variety

of properties and also be relevant for storing nuclear waste. The materials were cast rock, aluminum- oxide particles, purified bentonite, and kaolin.

All samples were cylindrical, with diameters of about 10 cm and heights of 13 cm. In order to give a uniform signal intensity across the image plane, the

receiver coil was made large enough to enclose the samples completely. Each

52
sample was placed in the receiver coil with the long axis of the sample and

coil oriented vertically and at right angles to the main field. The images

were obtained for slices 1 cm thick and in-plane resolution of 1 mm by 2 mm.

HIGH TEMPERATURE REACTING FLOWS GROUP

Numerical Modeling of High-Temperature Reacting Flows

R.W. Davis, E.F. Moore

High- temperature reacting flows are, in general, typified by strong

coupling between fluid mechanical and chemical kinetic processes. In most

practical systems, such reacting flows are characterized by large

fluctuations in species concentration and temperature which occur over small

spatial intervals. In order to gain an improved understanding of such

complex reacting flows, a joint numerical-experimental program is being

carried out. Because of its simple flow configuration, this program focuses

on the counterflow and axisymmetric jet diffusion flames. Computer codes are currently being developed to model these two systems. Although flame sheet

formulations are employed in these models, Lewis numbers can be arbitrary.

This is particularly important in the effort to simulate the H2 -O 2 counterflow burner experiments being carried out at NBS , since Lewis numbers

in these systems are much less than unity. The model being developed for the

axisymmetric jet diffusion flame will include the effects of unsteadiness,

particularly as related to pulsing of the fuel jet. Experiments are being

carried out in a collaborative effort at Wright- Patterson AFB and at NBS.

The computational models developed for these flames will provide complete

descriptions of the flow, species and thermophysical properties fields, and

will permit quick assessment of the effects of parameter variations.

Rigorous comparisons between numerical and experimental results will be made

at each level of code development to ensure that the models realistically

simulate the actual physics.

Destruction of Hazardous Waste in Fluidized Beds

A. Macek, N.O. Spears*, R. Chawla*, H.G. Semerj ian

Control of products of incomplete combustion, generated during

incineration of hazardous wastes, requires an understanding of rates and

mechanisms of oxidation and thermal decomposition of the principal

constituents (mainly chlorinated hydrocarbons). The experiments to provide

such an understanding should be performed under well -control led operating

conditions which simulate full-scale incineration systems. A literatur.

study, made earlier under the sponsorship of EPA, showed that at least

experimental research approaches should be considered: (a) laboratory

burners or furnaces; (b) high- temperature flow reactors (providing thcv

sufficient residence times for the reactant); and (c) fluidized bod.'. Th<

first approach (flame destruction) is convenient, but it does not of for g< control of three critical parameters for simulation of full-scale

incineration systems: temperature, residence time, and oxygen < <,; . :

•

53
Therefore, a decision has been made to explore the other two approaches,

starting with oxidation studies in fluidized beds.

\ So far, two studies were made in the NBS fluidized-bed reactor at high

temperatures, based on a novel optical technique, allowing observations in

the interior of the bed. The first of these, reported previously, was temperature measurement of burning char particles. The second study,

including the determination of mixing regimes for bed particles and

measurement of solids dispersion coefficients, has also been completed now

and a comprehensive report was written.

The existing fluidized-bed reactor has been modified to allow the

metering of gaseous reactants into the bed and on-line exhaust monitoring of

CO, CO2 and O2 , and a preliminary study of destruction of gas -phase reactants

in the bed has been completed. The study comprised four sets of experiments

in which chlorinated and non- chlorinated hydrocarbons (methyl chloride and

propane) were oxidized, each in both catalytic and non-catalytic beds. The

results show significant increase of oxidation rates in catalytic beds.

A new f luidized-bed reactor has been designed which will allow longer

gas residence times in the bed. The new reactor will be served by the same instrumentation and data acquisition systems as the dilute-phase flow reactor

which is currently used for black- liquor combustion studies: fiber-optic

pyrometry, on-line gas monitoring, etc. Future plans include several

possibilities: (a) parallel plug-flow and f luidized-bed oxidization and

pyrolysis studies of chlorinated hydrocarbons; (b) retention of chlorinecontaining reaction products in the fluidized bed by means of solid sorbents;

and (c) f luidized-bed destruction of solid and liquid agents. In all cases,

the emphasis will be on application of advanced measurement techniques (fiber

optics and lasers) to elucidation of in-situ reaction parameters.

*Howard University

Particle Formation in High Temperature Reacting Flows

M.R. Zachariah, H.G. Semerjian, D. Chin*, J.L. Katz*

Investigations are underway to determine the feasibility of using flames

as the reacting environment for the formation of refractory particles . The

goals of the project are to investigate the underlying physical - chemical

processes leading to particle formation and growth, and suggest ways one might control the underlying chemistry and physics through changes in process

parameters, to affect the final product purity, particle size and

polydispersity . Additionally, through the use of non- intrusive laser

diagnostics applied to investigating these processes, it is hoped that the

limitations and advantages of the various techniques will be clarified and

refined.

54
Current efforts have focused on the formation of silicon dioxide

particles in a counter- flow diffusion flame using a hydrogen-oxygen flame to

provide the temperature field and the radical pool. This geometry has been

shown to provide a flat, highly uniform environment suitable for optical

probing. In these experiments silane is used as the source of silicon and is

introduced in the fuel leg of the counter- flow reactor. Measurements are then made of the flame temperature field, particle diameters and particle

number densities. Temperatures have been measured by both fine-wire

thermocouples and OH absorption techniques. In-situ particle sizing is

conducted by dynamic light scattering experiments and/or dissymmetry

experiments. These two techniques were shown to give comparable results.

Number density measurements have been made using static light scattering

techniques in conjunction with Mie theory calculations.

The results to date suggest that by changing the silane loading one can greatly influence both the particle size and number density. Changes in the

equivalence ratio result in shifts of the region where particles are formed,

as well as their growth characteristics and final size. It has been shown

that the temperature affects both particle shapes and sizes. The results

suggest that particle formation and the eventual growth mechanism are highly

coupled to the precursor gas kinetics and that particle size, number density

and shape can be altered by changing process parameters.

*Johns Hopkins University

Flame Temperature Measurements by Laser Excited Fluorescence

J.J. Horvath, H.G. Semerjian

A new nonintrusive temperature measurement technique, based on laser

excited fluorescence, is being developed for measurements in high- temperature

chemically reacting flows. In this method, an upper electronic state is

populated from the ground state by means of laser excitation. The population

in this excited level is collisionally redistributed, then radiatively

decays, and the resultant fluorescence is detected as a function of energy

level. The temperature can be obtained by plotting the observed fluoresce:

intensities vs the upper energy level that the transition originates from.

All lines above the laser excited level will be found to fall on a straight

line and the slope of this line will yield the temperature. This plot

indicates the presence of a local Boltzmann distribution throughout the

higher energy levels. One can also measure two wavelengths simultaneou ; !

and obtain a temperature from a single laser pulse. The fluorescence

observed is anti -Stokes of the excitation pulse, hence this method is

applicable to high luminosity flames and conditions of high background 'd fluorescence. This method is applicable to both naturally occurring spe< :

- such as OH, CH and C 2 or atomic species seeded into the flame. Init ial

experiments have used gallium as the seeding species in premixed I h • tunable dye laser, pumped by a nitrogen laser, is used to excite the d • 5Si/ 2 transition of Ga at 403.3 nm and the resultant fluorescein . ! r<>;: ; e: levels is observed. A wide variety of premixed flames were st.udi.-d t >> determine the useful temperature range of this technique. Flan. -. •.•

55
were CH4

/Ar/O 2 , CH4/Air, C 2 H4/Ar/02 , and C 2 H4/Air. The temperature of these

flames could be varied from approximately 1950 to 2500 K depending on flow

conditions. Experimentally measured temperatures were found to be about 100-

150 K below the adiabatic flame temperature calculated using the NASA

computer program. Fluorescence signals were also obtained in an ethylene

diffusion flame, but an unexpected broad band fluorescence was observed which

yielded abnormally high temperatures. To correct for this broad band

fluorescence interference, computerized data reduction schemes were developed

Recent work has used an Nd-YAG pumped laser for greater spectral

coverage of the useful wavelengths. This work has centered on determining

the temperature range of useful thermometric species. We have also performed

measurements using time resolved fluorescence to measure collisional transfer

rates. We observed that the upward rates are faster than the downward as predicted by theory. Work will continue on both atomic and molecular seed

species in order to develop single laser pulse temperature measurement

techniques for use in industrial and scientific applications over a wide

range of temperatures.

High Speed Laser Tomography for Measurement of Concentration

and Temperature Distributions in Reacting Flows

H.G. Semerjian, D.R.F. Burgess

The technique of high speed laser tomography is under development to

allow rapid measurements of temperature and chemical species concentration

distributions throughout a two-dimensional "slice" within time varying

chemically reacting flow fields. Work has progressed from time averaged

measurements of steady phenomena, such as laminar diffusion flames and

gaseous jets, to real time measurements in sodium- seeded flames. Using the

experience gained, the temperature and OH concentration field were measured

in a premixed methane flame within five milliseconds. This was achieved by

sweeping an ultraviolet laser beam through the field every millisecond while

tuning the laser frequency over an OH absorption line. The experiment used

an axially symmetric flame, requiring only a single measurement angle. The

frequency scanning range of the dye laser is currently being extended so that

two OH lines can be scanned rapidly. This would enable the measurement of

temperature using a two-line ratio technique.

Current work has focused on rapid measurements in non- symmetric fields

at repetition rates up to 10 kHz, using a six-angle tomography approach. The

new system has been used to measure the particle concentration field in

rapidly fluctuating flames. Data have been obtained on the dynamics and

three-dimensional structure of large eddies formed in an ethene-air turbulent

diffusion flame. The frequency of eddy formation is controlled by

introducing fluctuations into the fuel stream, using a loudspeaker. The

formation, shedding, and break-up of eddies, marked by the soot particles

formed in the flame, have been observed with a time resolution of 1 ms. Details of eddy formation in the jet have also been observed using a laser

sheet beam located along the centerline of the jet. Titanium chloride is fed

56
into the fuel jet, and when in contact with combustion generated water, it

forms titanium oxide particles. Scattered light from the particles is used

for flow visualization. As a parallel effort, a number of alternative

reconstruction techniques have been investigated using computer simulations,

to identify the approach ideally suited to this experiment. The maximum

entropy method is found to be the most suitable, especially for

reconstructing the field from a small number of projections (e.g. six

angles)

Optical Sensing in Bioreactors

J.J. Horvath, A. Enriques*, H.G. Semerjian, A. E. Humphrey*

Recent advances in molecular biology have led industry and government

agencies to recognize the economic potential for applying these advances in a diversity of industrial sectors, including the production of new drugs, food

additives and chemicals, conversion of biomass, etc. However, implementation

of these new technologies requires measurement capabilities which do not

currently exist. Bioprocesses require very closely controlled environments,

normally realizable only in batch processes. This is mainly because of the

complex kinetics of most bioreactions, separate periods of growth and produc*

formation, biocatalyst degeneration, contaminant risks, and mechanical

difficulties of handling a rheologically complex material . Therefore

development of new on- line measurement techniques is critical for future

implementation of bioprocesses. Furthermore, non- intrusive measurement

methods are desirable to avoid difficulties associated with sampling,

contamination, long response time, etc.

Optical techniques, especially with the use of tunable lasers, provide

the best potential for making nonintrusive , rapid, and selective

measurements. Use of fiber optics can also enable the development of probes

which are sterilizable , can provide measurements with good spatial

resolution, and can be multiplexed to provide multipoint monitoring

capability. Laser- induced fluorescence (LIF) , Raman scattering, and infrur- -d absorption techniques will be utilized for measurement of key process

variables such as cell mass activity, cell concentration, and concentration

of substrates and products . Experiments have been carried out on fluorescence characteristics of the aromatic amino acids, indicating good

sensitivity and selectivity. The fluorescence characteristics of a seri>

dipeptides and polypeptides were studied to determine the effects of amino

acid sequence and various chemical functional groups on the observed

fluorescence spectra. The spectra of commercially produced biomolecule.-

such as antibiotics and artificial sweeteners, were also observed. The

fluorescence spectra of the components of a typical fermentation, i e. nutrient, and the product enzyme, have been examined and character i zed

function of excitation wavelength. Present work involves us in;-, then ;

• to monitor fermentation on-line using a flow-through cuvette. The

fermentation broth is pumped through the cuvette where laser induced

fluorescence spectra are measured, yielding information on the e.

- nutrient concentrations. The characteristic fluorescence spectre f myeast and nutrients are used to monitor the state of the ferment.it ion .u.d I

57
growth rate of yeast. The fluorescence can be correlated well with yeast dry

weight as determined by withdrawing samples. Work is also under way with the

University of Maryland, to understand the fluorescence of mixtures and to

develop techniques for determining single components in complex mixtures.

Groundwork has been laid for running a microbial fermentation to produce the

antibiotic bacitracin which will also be monitored by on-line fluorescence.

This is a completely different system which will demonstrate the

applicability of LIF to on-line monitoring of various type bioreactors. We

have also performed preliminary measurements using two-photon fluorescence

and fluorescence lifetimes which indicate good promise for improving

selectivity in the measurements. Fluorescence techniques are also expected

to provide a powerful tool for cell activity and intracellular kinetics

measurements. In the future, excitation/matrix, Raman and resonance Raman

scattering will be used to provide improved species selectivity.

*Lehigh University

Fluorescence Spectroscopy for Control of Paper Pulping Processes

J.J. Horvath, H.G. Semerj ian

There is an increasing need for the development of measurement science

and technology for on-line measurement of process variables in the pulp and

paper industry. Current process techniques for measurement of delignification rates in the pulping process are based on sampling and off-line

analysis systems. The resultant delay prevents the on-line control of the

digester, and results in less than optimum operating conditions. The ideal

process monitoring technique would be both an in-situ and real-time

measurement system, so that important variables of the cooking process can be

monitored and corrections applied before a cook is complete. The goal of

this project is to develop in-situ techniques, based on fluorescence

spectroscopy, for monitoring pulping processes.

In these studies, laser excited fluorescence of black liquor was investigated as a possible monitoring technique for pulping processes. A

pulsed dye laser was used to examine the fluorescence spectrum of black

liquor solutions. Various excitation wavelengths between 280 and 403 nm were

used. Black liquor fluorescence spectra were found to vary with both

excitation wavelength and black liquor concentration. Laser excited

fluorescence was found to be a sensitive technique for measurement of black

liquor. The technique provides good detection limits and linear response

over a large dynamic range. Measurements have recently been made on pulping

liquors obtained from a paper mill. During the course of a 3 hour pulp cook,

six or seven samples were obtained at various times from two separate runs. Laser excited fluorescence spectra were obtained, from these very optically

dense liquors, using a backscatter configuration without any sample dilution.

The fluorescence spectra obtained from these samples were found to vary

during the cook, indicating good possibility of using fluorescence for a process control monitor. Even though we saw changes in the fluorescence

intensity, the properties of these liquors were not well known. To relate

fluorescence spectra to cooking liquors one should work with well

58
characterized cooks whose properties are known. We are now working with a person at the Institute for Paper Chemistry who is providing us with liquors

of known lignin concentrations made in a laboratory digester. The results in

these samples have been good, where lignin concentrations were found to be

linear in fluorescence intensity. The fluorescence spectrum also indicated a chemical change occurring near the end of a cook, something speculated on in

the literature. We have also looked at the fluorescence of paper and paper

fibers and found the signal to be related to the lignin content. Further

studies will involve studying more laboratory pulp cooks to determine all

parameters that affect fluorescence signals in order to develop a practical

on-line measurement and control technique for the pulp and paper industry.

Particulate and Droplet Diagnostics in Spray Flames

C. Presser, A.K. Gupta*, H.G. Semerj ian

Dynamics of spray flames are being studied to investigate droplet

vaporization, pyrolysis, combustion, and particulate formation processes, and

to delineate the effect of chemical and physical properties of fuels on the

above processes. The results of this study will provide an experimental data

base, with well-defined boundary conditions, for the development and

validation of spray combustion models being developed by the Jet Propulsion

Laboratory, and Sandia and Los Alamos National Laboratories. The experiments

are being carried out in a spray combustion facility, with a moveable -vane swirl burner, which simulates operating conditions found in practical

combustion systems. A combination of non- intrusive probing techniques is

being used to obtain comprehensive data on the spray combustion

characteristics, including soot particle and droplet size, number density and

volume fraction, gas composition, velocity and temperature fields.

Current efforts are focused on obtaining laser ensemble scattering and

Doppler velocimetry measurements with an air-assist atomizer typical of thos<

used in industry, especially for heavy fuels. Unlike the pressure atomizer

studied previously, this injector can provide different atomization

characteristics by varying the atomizer air flow rate for the same fuel flow

rate; it thus allows one to study the effects of atomization on overall spr

and spray flame structure. Flame characteristics are found to change

dramatically as the atomizer air flow is increased, going from a sluggish

flame (typical of pressure - atomized flames) to an intense fireball. This

particular research nozzle is also being used by investigators at the

University of California- Irvine and Carnegie -Mellon University, which will

allow for direct comparison of our results and establish a broad experiirc i data base. In addition to the ensemble light scattering measurements. <!.,• will be compared with other measurement techniques: a) phase/Doppler

interferometry; b) light intensity deconvolution technique (single par* ' counters); and c) laser diffraction technique (ensemble line -of - s i ght:

technique). Extinction data are being recorded with the air-assist •. •

• to obtain information on the degree of light attenuation through t:he ;

: > . and spray flame. In an effort to significantly reduce the data acqui: it i t time for the ensemble scattering measurements, a new detection sv.t. ; h

been assembled in which two detectors are used to measure both sr.it t.-i

59
coefficients (Qhh an<i Qw) simultaneously, thus determining the instantaneous

values of the polarization ratio. This arrangement will avoid any

measurement uncertainties associated with the averaging process, and may be

applicable as a single particle counter. One of the topics of concern is the

effect of fuel properties on spray and flame characteristics. Two sets of

experiments are planned, one with heptane and the other with No. 6 residual

oil as fuels. Heptane is a single -component fuel which will provide

propitious data for modeling efforts. The experiments with No. 6 fuel oil

will provide data which are of greatest interest to industry, because of the

difficulties encountered in atomization, flame stability and pollutant

emission characteristics.

*Univers i ty of Maryland

Fundamental Studies of Black Liquor Combustion

A. Macek, N.D. Amin, S.R. Charagundla, H.G. Semerjian

Efficient operation of black liquor (BL) recovery boilers requires more fundamental information on combustion of BL droplets than is currently

available. The problem of measurement of the pertinent combustion parameters

is addressed by a joint project with the Institute of Paper Chemistry under

DoE sponsorship. The NBS tasks of this joint project are directed toward

studies of vaporization, pyrolysis, ignition, and combustion of dilute

streams of BL droplets. This is currently being done in the high- temperature

dilute-phase plug flow reactor (DPFR) , specifically designed for such

studies

A positive-displacement technique, in which individual droplets are extruded from a hollow needle, was developed earlier in this project for on- demand generation of highly viscous droplets with diameters of the order of 1 mm. This technique is now being used for injection of BL droplets (with up

to 65% solids) into high- temperature streams in the DPFR. High-speed

photography has been used for: (a) observation of the processes of BL

droplet formation and detachment from the needle tip, (b) measurement of

diameters prior to detachment, (c) measurement of in-flight droplet diameters

after detachment, and (d) measurement of velocities of droplets falling in a counterflowing hot gas stream. An extensive series of tests has been made,

with droplet diameters ranging from 1.3 to 3.0 mm, gas temperatures from 700

to 875 C, oxygen concentrations in the gas from 8 to 21%, and droplet

residence times up to about 1 s. These in-flight studies are nearly complete

and a new phase of studies is being planned, oriented toward measurement of

particle sizes in fumes above char beds in recovery boilers by means of laser

scattering.

The DPFR constructed in this project will also be used for investigation

of pyrolysis and oxidation of other fuels (such as coal-water) as well as oxidative destruction (incineration) of hazardous wastes. The reactor is now being equipped for (a) ratio pyrometry measurements; (b) sample - extraction

60
for gas -chromatographic analysis; (c) on-line monitoring of exhaust species

(CO, CO 2 , NO, SO 2 , H2 S, O2 , and hydrocarbons); and (d) computerized data

acquisition.

Optical Diagnostics for Metal Powder Atomization Systems

C. Presser, H.G. Semerjian

Rapidly solidified metal powders are important to systems requiring

advanced materials. They provide the basis for alloys which exhibit, after

consolidation, high strength- to -weight ratios, improved fracture toughness

and fatigue resistance, unique magnetic properties, and high corrosion

resistance. A collaborative research program has been initiated with the NBS

Institute for Materials Science and Engineering, to apply laser diagnostic

techniques, to investigate metal powder atomization and rapid solidification

processes in the NBS metal powder atomization research facility. Liquid

breakup processes of the molten metal in the vicinity of the injector are being investigated, in addition we apply sensors to monitor particle size in

the atomizer exit passage for feedback and control purposes. Detailed

process knowledge, along with an integrated system of sensors and expert

systems for feedback and control, can then be used to monitor and control the

atomization process, and to provide desired powder characteristics.

Particle size measurement techniques are currently being evaluated to

determine their applicability to jet break-up and droplet formation processes

in the metal powder atomization chamber. The techniques under consideration

to measure particle size, number density and velocity include a) the ensemble

light scattering technique, b) the phase/Doppler interferometer, and c) the

scattering intensity deconvolution technique. One system will be used for

diagnostics in the atomization chamber, to provide data for development of

process models, for input into expert systems, and for process optimization.

High speed cinematography will also be implemented, along with a laser sheet

beam, to illuminate the spray jet and provide qualitative data on the genera',

features of the liquid jet and droplets. In addition, a second set of

experiments is under way to obtain particle size measurements in the exit

section of the atomizer facility. A laser light diffraction technique has

been chosen to provide particle size distribution measurements along a lineof-sight. This particle size distribution, averaged along a cross section : the process stream, can then be used for process feedback and control

Restrictions on the degree of obscuration along the measurement path durit. an atomization run has to be considered. Therefore, to evaluate this prob’. . under realistic conditions, the exit section of the atomizer chamber is bo::

modified to incorporate two windows 180° apart. Transmission measurorron: ; and video movies, taken during several metal powder runs, have indicated

need for purging the windows in order to reduce deposition of par’ i c 1

. >• obscuration of the laser beam. Off-line measurements are planned so th.it • :i problem can be further studied in a more controlled environment.

61
PROCESS SENSING GROUP

Thin Film Thermocouples for Heat Engines

K.G. Kreider, S. Semancik

The goal of this project is to demonstrate the feasibility of a materials system and fabrication technique for measuring temperatures inside

the combustion chamber of ceramic- insulated engines using thin film

thermocouples. The ceramic insulating materials under investigation include

partially stabilized zirconia (PSZ) in both monolithic and plasma sprayed

forms and alumina (AI 2 O 3 ) . The thermocouple systems have included type E

(chromel-constantan) , type N (nisil-nicrosil) , and platinum-platinum (with 6 % rhodium)

Adhesion studies for these systems indicate that a reactive metal bond

coat such as Cr or Ti is very useful in insuring a strong (70 MPa) bond

between Pt and PSZ or AI 2 O 3

. This bond coat and its stability have been

studied using X-ray photoemission spectroscopy and depth profiling using

secondary ion mass spectroscopy. Scanning electron microscopy and electron

microprobe analysis have indicated that the sputtered films were produced

with the same composition as the target alloys, and continuous, strong, porefree deposits can be sputtered 1-4 /xm thick. Calibration, high temperature

exposure, and flame testing of the sputtered thin film deposits indicate the

sensitivity to the atmosphere and alloy changes by diffusion of the thin

films. Type E and type N thermocouples are unstable at 1000 K and are not

recommended. Type S thin film thermocouples, however, appear very promising

and a project to evaluate thin film thermocouples in diesel engines is under

way

Small (1.0 cm) diameter plugs with NBS sputtered thin film type S thermocouples deposited on the plasma- sprayed partially- stabilized zirconia

insulating layer are being used to monitor the surface temperature of a diesel engine. This plug sensor is inserted in the second intake valve port

and is used to measure heat transfer and temperature excursion with 2-4 ms time resolution. This technology will provide the first accurate data of its

type and should aid in the adiabatic engine design.

Chemical Gas Sensors

S. Semancik, T.B. Fryberger, J.W. Erickson

The electrical conductivity of tin oxide, SnC> 2 , can be altered by both

oxidizing and reducing gases. This behavior makes SnC>2 suitable for use in a variety of solid state gas sensing applications. During the last year our studies have sought to provide detailed information on the ways in which

oxygen vacancies affect the electrical properties of SnC>2 and related oxide

materials. We have also been particularly interested in determining the

extent to which surface phenomena dominate signal generation processes, and

in studying the mechanisms by which metal overlayers can enhance the sensing

performance and stability of tin oxide.

62
Experimental efforts have focused on SnO2(H0) single crystals (the most

stable crystallite) that have been modified to examine effects that would

occur in operating devices. Oxygen vacancy defects were investigated by

first using oxidation procedures to form pure, nearly perfect Sn02 surfaces,

and then introducing oxygen vacancy defects by heating. The defect density,

electronic structure and electrical conductivity at these surfaces were

characterized using ion scattering, ultraviolet photoemission and an ultrahigh vacuum four-point probe developed in our laboratory. This work has

shown that two distinct types of oxygen vacancies can develop at the SnC>2

surface, and that each has a different effect on the electrical conductivity.

Such findings are of importance not only for understanding one class of solid

state sensing materials, but can also impact our understanding of other key

technological oxides (e.g. in microelectronics and superconductivity).

Metal overlayers have also been examined on Sn02(110) as a way to

enhance adsorption and selectivity in sensor response. Most of our work,

thus far, has concentrated on palladium adlayers (which can be used to

enhance hydrogen response) , but preliminary work has also been done with

silver and tin. Besides characterizing the additive - SnC>2 interactions, we were able to demonstrate increased efficiencies in model H2 sensors

containing monolayer coverages of Pd.

Our efforts on controlling surface defect concentrations and the

dispersion of surface additives are aimed at developing improved materials

for solid state gas composition measurements. Continuing studies in these

areas are expected to further advance the gas sensing field toward a reliable

thin film technology, ultimately capable of producing sensor arrays which

could perform multiple gas analyses.

IrO g Ionic Sensors

K.G. Kreider, P.H. Huang, S. Semancik

Reactively sputtered iridium oxide is being considered as a pH sensing

material. It has the advantage that thin films could be fabricated

inexpensively on probes which would be smaller and more durable than

presently used glass electrodes. The IrC>2 is not attacked at high

temperatures and pH levels which would destroy the glass electrode. We h.r.v

produced reactively sputtered iridium oxide pH sensing films (SIROF) on A 1 substrates. Long-term stability of the SIROF electrodes, hysteresis effec'

and foreign ion interferences need to be investigated for practical pH

sensing applications.

This research involves the understanding of the structure of I r0 7 . IrC^-pH solution interfaces. For all oxides studied so far by other

researchers including Ti02, 7-AI2O3, a-Fe203, Si02, and Mn02 , the • ’

; surface charge density versus pH increases with pH without any indi. , reaching a plateau. In order to explain the phenomena associated : •

:

' • very high surface charge densities observed at the oxide-solut ion in'--: : various theoretical models have been proposed. These models includ.- • double layer model (GCSG) , the porous double layer model, the gel

63
model, the transition layer model, and the site-binding model. However, it

appears that no satisfactory model for the oxide - solution interface has

emerged to date. Hydration, hydroxylation , and acid-base properties are all

factors which require special attention. Central to any model of the oxide

solution interface is the molecular structure of the layer of water at the

oxide surface. The dielectric properties of water molecules, which are physisorbed or chemisorbed on the oxide surface in the compact layer need to

be understood. For the IrC>2 - solution interface, current efforts are underway

to investigate adsorbed water in the electrochemical interface and the

fundamental properties affecting the electrochemical behavior of hydrous IrC>2

films. Experimental techniques of open circuit potential measurement, dc and

ac voltammetry, and impedance spectroscopy are being used to study IrC>2-

solution interfaces for: (a) the long-term stability of the SIROF electrodes

in the pH range 2 to 12 at temperatures up to 95 °C; (b) the hydrated SIROF

and the variation of its acidity with change in the iridium oxidation state;

and (c) the reduced and oxidized form of the SIROF. These properties are strongly influenced by the hydrated nature of the Ir02 layer.

Chemical changes produced at the solution- oxide interface are believed

to be the origin of instabilities in the pH response of Ir02-based sensors. Therefore, we have characterized the surface compositions of a number of

iridium oxide - related materials using x-ray photoemission (XPS) and secondary

ion mass spectrometry (SIMS). We have analyzed commercial powders, like

1^03- XH2O and Ir(0H)4, as standards, and we have also studied IrC>2 films

fabricated within our group. These films have been examined in "as

fabricated" form, after baking or autoclaving, and following use of the films

as electrodes (sensors) in pH- controlled solutions. Binding energy shifts of

up to 2 eV have indicated significant differences in the chemistry at these

film surfaces, and some of the results suggest that hydroxylation processes

may be altering the performance of IrC>2 sensors.

The results of the electrochemical testing, surface analysis, and the

study of the relationships between sputter fabrication and structure of the

Ir02 were presented in Tokyo, Japan at the 4 th International Conference on Sensors and Actuators

Humidity Calibration

S . Hasegawa

A new low frost point humidity generator was constructed during the last

year. This new facility will enable us to calibrate precision humidity

measurement instruments to below 1 ppm H2O content. Low moisture content is

particularly significant for carrier gases in the fabrication of integrated

circuits

64
Humidity Sensors

P . H . Huang

The material design for humidity sensing and measurement using

halogenated organic polymer membranes has been granted a patent, #4,681,855.

The invention is an improvement over existing devices because of its expected

long life, lasting accuracy, and ability to be used at high temperatures and

humidities. The membrane is a thin film of hygroscopic, fluorinated organic

polymer having pendant functional groups of a relatively strong sulfonic acid

type and groups of a relatively weak carboxylic acid type. Since the

sulfonic acid functional group attracts water molecules more strongly than

the one of carboxylic acid, the acidic functional group ratio determines the

amount of water in the polymer. By varying the ratio of these acidic

functional groups, a wide range of humidity can be measured accurately with

low hysteresis. Potential applications are especially in the areas of

controlling the drying processes that support industries such as textiles,

paper, chemicals, and food. Meteorological and electronics applications are also feasible.

A new technique based on high frequency surface acoustic wave

spectroscopy has also been investigated for humidity sensing. Polar water

molecules in ambient moist air can be made to interact with the electric and

acoustic fields of a surface acoustic wave (SAW) in a piezoelectric crystal

surface. The interaction causes a change in the amplitude of the received

surface wave which is proportional to the energy density of the wave. An

amplitude-modulated SAW technique, which does not utilize adsorptive

coatings, has been used to study this electro-acoustic interaction for

humidity sensing in the range 90 to 98% RH. The sensor system consists of

two identical high frequency, wide band SAW delay lines. One is used as a reference channel with shorted electric fields at the surface. The reference

delay line is maintained in an environment of nearly zero percent relative

humidity. The ratio of voltage output from the sensing channel to that of

the reference channel has been measured. An experimental relationship exisrs

between the measured voltage ratio and the relative humidity in the range

from 90 to 98% for SAW frequencies in the range between 210 and 250 MHz.

Several mechanisms are proposed for the electro-acoustic interactions betve< • water molecules and high frequency surface acoustic waves.

5. PUBLICATIONS

Benson, K.R., Mease, N.E., Kulin, G. and Mattingly, G.E., NBS primary

calibration facilities for air flowrate, air speed and slurry flow,

Proc . Int. Symp . on Fluid Flow Measurement, Amer. Gas Assoc., Arlingt

VA, (Nov. 1986); see also InTech Magazine (Jan. 1987).

Charagundla, S.R. and Macek, A., Entrainment of irregularly shaped par: ;

application to solid-fuel furnace environments, AIChE 1986 Ani:’i,'.

Meeting, Miami Beach, FL (Nov. 1986) (submitted).

65
Clay, D.T., Grace, T.M., Kapheim, R.J., Semerjian, H.G., Macek, A. and

Charagundla, S.R., Fundamental studies of black liquor combustion,

Report No. 1, Dept, of Energy Report DoE/CE/40637 -T1 (DE85013773) (Jan.

1985)

Clay, D.T., Lien, S.J., Grace, T.M., Macek, A., Semerjian, H.G., Amin, N. and

Charagundla, S.R., Fundamental studies of black liquor combustion,

Report No. 2, Dept, of Energy Report (submitted Jan. 1987).

Clay, D.T., Semerjian, H.G. and Macek, A., Black liquor combustion in a laboratory flow reactor, Proc . TAPPI 1987 Eng. Conf., New Orleans, LA

(Sept. 1987).

Cleveland, W.G., Jr. and Gaigalas, A.K., Measurement of solids fraction in

two-component slurries, Proc. Sensors Expo., pp . 41-48 (Sept. 1987).

Cox, D.F., Fryberger, T.B. and Semancik, S., Oxygen vacancies and defect

electronic states on the Sn02 ( 110) -

| x | surface, Phys . Rev. B (in

preparation)

Cox, D.F., Fryberger, T.B., Erickson, J.W. and Semancik, S., Summary

abstract: Surface properties of clean and gas-dosed Sn02(110), J. Vac.

Sci. Tech., Vol. A5(4), pp . 1170-1171 (1987).

Erickson, J.W., Fryberger, T.B. and Semancik, S., Abrupt metal/semiconductor

interfaces on a metal oxide, J. Vac. Sci. Tech, (submitted).

Erickson, J.W. and Semancik, S., An economical UHV four-point resistivity

probe, J. Vac. Sci. Tech., Vol. A5(l), pp . 115-117 (1987).

Erickson, J.W. and Semancik, S., Surface conductivity changes in Sn02(110):

effects of oxygen, Surf. Sci. (in press).

Fryberger, T.B., Grant, J.L. and Stair, P.C., Interaction of boron with

Mo(100) and its effect on surface chemistry, J. Vac. Sci. Tech., Vol.

A5 (4) , pp. 858-862 (July 1987).

Gaigalas, A.K. and Cleveland, W.G., Jr., Measurement of solids fraction,

poster session on fluidization and fluid-particle systems, AIChE 1987

Annual Meeting, New York, NY (Nov. 1987) (submitted).

Gosh, A.K. and Ulbrecht, J.J., Bubble formation from a sparger in a stagnant

polymer solution, AIChE 1987 Annual Meeting, New York, NY (Nov. 1987)

(submitted)

Hasegawa, S., National basis of accuracy in humidity measurements, ISA

Trans., Vol. 25, No . 3 , pp . 15-24 (1986).

Hasegawa, S., Definitions of humidity terms, Proc. RADC/NBS Int. Workshop on Moisture Meas . and Control for Microelectronics (1986) (in press).

66
Horvath, J.J. and Semerjian, H.G.

,

Laser induced fluorescence for process

control in pulp and paper industry, Proc . 5th Int . Congress on Appl. of

Lasers and Electro-Optics (ICALEO '86), Arlington, VA (Nov. 1986).

Horvath, J.J. and Semerjian, H.G., LIF for sensing in the pulp and paper

industry, CLEO/IEQE , Baltimore, MD (Apr. 1987) (submitted).

Horvath, J.J. and Semerjian, H.G., Laser induced fluoresence for diagnostics

of biomolecules, AIChE 1987 Annual Meeting, New York, NY (Nov. 1987)

(submitted)

Horvath, J.J. and Semerjian, H.G., Collisional energy transfer and flame

temperature measurements using laser induced fluorescence, AIChE 1987

Annual Meeting, New York, NY (Nov. 1987) (submitted).

Horvath, J.J. and Semerjian, H.G., Temperature measurements using laserinduced fluorescence and collisional energy transfer, Poster paper,

194th ACS National Meeting, New Orleans, LA (Sept. 1987) (submitted).

Huang, P.H., A new humidity sensor and its thermodynamic characterization,

Proc. of 13th Ann. Meeting of Federation of Analytical Chem. and

Spectroscopy Soc., p. 536 (Oct. 1986).

Huang, P.H., Surface acoustic wave microsensors using diffused substrates,

Sensors and Actuators (submitted)

Huang, P.H., Halogenated polymeric humidity sensors, Sensors and Actuators

(1987) (in press)

Huang, P.H., Surface acoustical wave spectroscopy for high humidity, Proc.

4th Int. Conf. on Solid-State Sensors and Actuators (Transducers '87),

Tokyo, Japan, pp . 462-466 (June 1987).

Huang, P.H., Humidity sensing and measurement employing halogenated organic

polymer membranes, U.S. Pat. No. 4, 681, 855 (July 1987).

Huang, P.H. and Chiang, C.K., Solid polymeric electrolytes as humidity

sensing material, Proc. Eurosensors - 3rd Conf. on Sensors and

Applications, Cambridge, England, pp . 11-12 (1987).

Jones, F.E., Collection and analysis of organic compounds in air: an annotated bibliography [1976-1986], Nat. Bur. Stand. (U.S.) Interim

Report, NBSIR 87-3527 (Feb. 1987).

Klebanoff, P.S., Cleveland, W.G. and Tidstrom, K., On the interaction of

three-dimensional roughness element with a laminar boundary lav. r. Tech. Rept., AEDC-TR-87-7 (Mar. 1987).

Kreider, K.G., Biancaniello , F.S. and Kaufman, M.J., Sputter depos i : i <>: icosahedral Al , Mn and Al-Mn-Si, Scripta Met., Vol

21, p. 65 7 1987) .

67
Kreider, K.G., Seraancik, S., and Erickson, J.W., Instability in pH measure- ments of sputtered IrC>2 films, Proc . 4th Int . Conf. on Solid-State

Sensors and Actuators (Transducers '87), Tokyo, Japan, pp . 734-737

(1987) .

Kulin, G. and Mattingly, G.E., NBS calibration services for meters flowing

air: 1. Low flowrates -piston prover techniques, Nat. Bur. Stand. (U.S.)

Interim Report (Aug. 1986) (submitted).

Kulin, G., Huang, P.H. and Mattingly, G.E., NBS calibration services for

meters flowing air: 2. Medium flowrates -bell prover techniques, Nat.

Bur. Stand. (U.S.) Interim Report (Aug. 1986) (submitted).

Macek, A., Charagundla, S.R., Allen, J.D. and Semerjian, H.G., A study of

combustion spectra from an entrained- flow gasifier, DOE Report

(submitted)

Macek, A. and Amin, N.D., A study of solids circulation in f luidized-bed

combustors, Proc. 21st Int. Combustion Symp . , Munich, W. Germany, Aug.

1986 (in press )

Macek, A. and Amin, N.D., Characterization of solids mixing in a hightemperature fluidized bed, AIChE 1986 Annual Meeting, Miami Beach, FL

(Nov. 1986) (submitted).

Macek, A. and Amin, N.D., Solids dispersion coefficients in high- temperature

fluidized beds, AIChE 1987 Annual Meeting, New York, NY (Nov. 1987)

(submitted)

Macek, A. and Amin, N.D., Characterization of solids mixing in a laboratoryscale fluidized bed, DoE/METC Report (in press).

Madey, T.E., Benndorf, C. and Semancik, S., Influence of electronic and

geometric structure on desorption kinetics of the isoelectronic polar

molecules NH 3 and H2 O, Springer Series in Surface Science 8 : Kinetics

of Interface Reactions, Ed. by M. Grunze and H.J. Kreuzer, pp . 175-181

(1987) .

Mattingly, G.E., NBS calibration services for meters flowing air: 3. High

flowrates -pressure , volume, temperature, and time techniques with sonic

nozzle transfer standards, Nat. Bur. Stand. (U.S.) Interim Report

(Aug. 1986) (submitted).

Mattingly, G.E., Yeh, T.T., Robertson, B. and Kothari, K. , NBS research on "in-situ" flowmeter calibrations, Proc. of AGA Distribution & Transmission Conf., Amer. Gas Assoc., Las Vegas, NV (May 1987).

Mattingly, G.E., Yeh, T.T. and Robertson, B., An experimental study of vortex

shedding in a generic flowmeter geometry, Nat. Bur. Stand. (U.S.)

Interim Report (July 1987) (submitted).

68
Mease, N.E., NBS calibration services for instruments measuring airspeed,

Nat. Bur. Stand. (U.S.) Interim Report (Aug. 1986) (submitted).

Mease, N.E., Parametric considerations in the use of anemometer calibration

data, Proc. 6th Symp . on Meteorological Observations and Instrumentation, Am. Meteor. Soc. (Jan. 1987).

Presser, C., Gupta, A.K., Semerjian, H.G. and Santoro, R.J., Droplet/air

interaction in a swirl - stabilized spray flame, Proc. 2nd ASME/JSME

Therm. Eng. Joint Conf . , Vol . 1, pp . 73-83, ASME , New York, NY (Mar.

1987).

Presser, C., Gupta, A.K. and Semerjian, H.G., Examination of liquid fuel

spray structure using laser diagnostics, Proc. 1st Ann. Conf. on Liquid

Atomization and Spray Systems (ILASS Americas '87), Madison, WI (June

1987).

Presser, C., Gupta, A.K.

,

Santoro, R.J. and Semerjian, H.G., Laser

diagnostics for characterization of fuel sprays, Proc. 5th Int. Congress

on Applications of Lasers and Electro -Optics (ICALEO '86), Vol. 58, pp

160-167, Arlington, VA (Nov. 1986).

Presser, C., Gupta, A.K., Semerjian, H.G. and Santoro, R.J., Effect of

combustion air swirl on fuel spray characteristics from a pressure-jet

atomizer, Combustion and Flame (submitted).

Presser, C., Gupta, A.K., Semerjian, H.G. and Santoro, R.J., Application of

laser diagnostic techniques for examination of fuel spray structure,

Chem. Eng. Commun. (submitted).

Robertson, B. and Ulbrecht, J.J., Measurement of shear rate on an agitation

in a fermentation broth, Biotechnology Processes Scale-up and Mixing,

Ed. by C.S. Ho and J.Y. Oldshue , AIChE (1987).

Robertson, B., Tribollet, B. and Deslouis, C., Measurement of diffusion

coefficients by DC and EHD electrochemical methods, J. Electrochemical

Soc. (submitted).

Santoro, R.J., Yeh, T.T., Horvath, J.J. and Semerjian, H.G., The transport

and growth of soot particles in laminar diffusion flames, Comb. Sci.

Tech., Vol. 53, pp . 89-115 (1987).

Santoro, R.J. and Miller, J.H., Soot particle formation in laminar diffusif

flames, Langmuir, ACS J. of Surfaces and Colloids, Vol. 3, pp . 244-254

(1987).

Semancik, S. and Cox, D.F., Fundamental characterization of clean and gas

dosed tin oxide, Sensors and Actuators, Vol. 12, pp . 101-106 (198

Semerjian, H.G. and Horvath, J.J., Optical measurements for biochcmi*

processes, Proc. Conf. on Frontiers in Bioprocessing, Boulder

1987) (in press)

69
Semerjian, H.G. and Ray, S.R., Investigation of large scale structures in

flames using laser tomography, 6th Int . Physico-Chemical Hydrodynamics

Conf., Oxford, England, Apr. 1987 (submitted).

Semerjian, H.G., Ray, S.R. and Emmerman, R.J., Diagnostics of large scale

structures in flames using laser tomography, OSA/Int. Laser Sci. Conf.,

Seattle, WA (Oct. 1986) (submitted).

Solomon, P., Best, P., Carangelo, R. , Markham, J., Chien, P., Santoro, R.J.

and Semerjian, H.G., FT-IR emission/transmission spectroscopy for in

situ combustion diagnostics, Proc . 21st Int. Symp . on Combustion,

Munich, W. Germany (Aug. 1986) (in press).

Ulbrecht, J.J., Particle transport phenomena in non-Newtonian liquids, AIChE

1986 Annual Meeting, Miami Beach, FL (Nov. 1986) (submitted).

Whetstone, J.R., Cleveland, W.G., Baumgarten, G.P. and Woo, S., NBS

calibration services for water flowrate measurement, Nat. Bur. Stand.

(U.S.) Interim Report (Aug. 1986) (submitted).

Whetstone, J.R., Cleveland, W.G., Bateman, B.R. and Sindt, C.F., Measurements of coefficients of discharge for concentric, flange - tapped

square -edged orifice meters in natural gas over the Reynolds number

range 25,000 to 4,500,000, Nat. Bur. Stand. (U.S.) Tech. Note

(submitted)

Whetstone, J.R., Cleveland, W.G., Baumgarten, G.P., Woo, S. and Croarkin,

M.C., Measurements of coefficients of discharge for concentric,

flange - tapped , square -edged orifice meters in water over the Reynolds

number range 1,000 to 2,700,000, Nat. Bur. Stand. (U.S.) Tech. Note

(submitted)

6 . CONFERENCES AND WORKSHOPS

CONFERENCES

Sessions on Proving Devices and Laboratories (I and II) at the International Symposium on Fluid Flow Measurement, American Gas Association,

Arlington, VA, Nov. 16-19, 1986. Organized and chaired by G.E.

Mattingly

Session on Spray Combustion at the Fall Technical Meeting of the

Combustion Institute/Eastern Section, San Juan, PR, Dec. 15-17, 1986.

Chaired by H.G. Semerjian.

Sessions on Combustion Fundamentals at the Second ASME/JSME Thermal

Engineering Joint Conference, Honolulu, HI, Mar. 23-27, 1987. Three

sessions organized and one session chaired by H.G. Semerjian.

70
DoE/NBS Black Liquor Research Review Meeting, Gaithersburg, MD , July 28-

30, 1987. Organized by H.G. Semerjian.

Session on Heat Transfer in Furnaces at the ASME/AIChE/ANS 24th National

Heat Transfer Conference, Pittsburgh, PA, Aug. 9-12, 1987. Chaired by

C. Presser.

Session on Sprays at the Eastern Section Meeting of the Combustion

Institute, Gaithersburg, MD, Nov. 2-5, 1987. Chaired by C. Presser.

Sessions on Reaction Engineering and Combustion Processes, and on New

Experimental Techniques for High Temperature Reacting Flows at the AIChF.

1987 Annual Meeting, New York, NY, Nov. 16-20, 1987. Organized and

chaired by H.G. Semerjian.

WORKSHOPS

Hosted NBS Workshop on Optical Particle Sizing Techniques, held on Nov.

11, 1986 at NBS, Gaithersburg, MD. Organized and chaired by H.G.

Semerj ian

Hosted Workshop for the Industry-Government Consortium on Flowmeter

Installation Effects Research, held on June 1, 1987 at NBS,

Gaithersburg, MD. Organized and chaired by G.E. Mattingly.

71
NBS-1 1 4 A (REV. 2-6C) U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO. NBSIR 87-3079

2. Performing Organ. Report No. 3. Pu bl i cation D ate

February 1988

4. TITLE AND SUBTITLE

CENTER FOR CHEMICAL ENGINEERING TECHNICAL ACTIVITIES: FISCAL YEAR 1987

5. AUTHOR(S)

J. Hord, Editor

6. PERFORMING ORGANIZATION (If joint or other than NBS, see i n stru ction s)

national bureau of standards

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8. Type of Report & Period Covered

Research Summary

10-86 to 09-87

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP)

10. SUPPLEMENTARY NOTES

( ] Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant in formation. If document includes a significant

bi bl iography or literature survey, mention it here) Technical research activities performed by the Center for Chemical Engineering

during the Fiscal Year 1987 are summarized herein. These activities fall within

the general categories of process measurement, thermophysical properties data,

and chemical engineering science. They embody: development and improvement of

measurement principles, measurement standards, and calibration services such as volumetric and mass flow rates, liquid volume, liquid density, and humidity;

generation (via accurate measurement and advanced predictive models) of reliable

reference data for thermophysical properties of pure fluids, fluid mixtures, and

solids of vital interest to industry; and development of improved correlations,

models, and measurement techniques for complex flows, heat and mass transport,

mixing, and chemically reacting flows of interest in modern unit operations.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

calibrations; chemical engineering; data; fluid mechanics; fluid properties,

process measurement; research; sensors; solid properties; thermophysics, unit

operations.

13. AVAILABILITY

QC] Unl imited

| | For Official Distribution. Do Not Release to NTIS

[ 1 Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.

[ X] Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

84

15. Price

USCOMM-DC 6043-P 80

a