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NBSIR 79-1617

FILE COPY

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OCT 1 0 1979

LIQUEFIED NATURAL GAS RESEARCH

at the

NATIONAL BUREAU OF STANDARDS

PROGRESS REPORT FOR THE PERIOD

1 JANUARY - 30 JUNE 1979

THERMOPHYSICAL PROPERTIES DIVISION, NATIONAL ENGINEERING LABORATORY,

NATIONAL BUREAU OF STANDARDS, BOULDER, COLORADO

NBSIR 79-1617

LIQUEFIED NATURAL GAS RESEARCH

at the

NATIONAL BUREAU OF STANDARDS

Thermophysical Properties Division

National Engineering Laboratory

National Bureau of Standards

Boulder, Colorado 80303

Progress Report for the Period

1 January - 30 June 1979

U.S. DEPARTMENT OF COMMERCE, Juanita M. Kreps, Secretary

Luther H. Hodges, Jr., Under Secretary w Jordan J. Baruch, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
Prepared for:

American Gas Association, Inc.

1515 Wilson Boulevard

Arlington, Virginia 22209

LNG Density Project Steering Committee

(in cooperation with the American Gas Association, Inc.)

Pipeline Research Committee

(American Gas Association, Inc.)

1515 Wilson Boulevard

Arlington, Virginia 22209

Gas Research Institute

10 West 35th Street

Chicago, Illinois 60616

U. S. Department of Commerce

Maritime Administration

Washington, DC 20235

U. S. Department of Commerce

National Bureau of Standards

National Engineering Laboratory

Boulder, Colorado 80303

U „ S. Department of Commerce

National Bureau of Standards

Office of Standard Reference Data

Washington, DC 20234

U. S. Department of Commerce

National Bureau of Standards

Office of International Standards

Washington, DC 20234

LNG Custody Transfer Measurements Supervisory Committee

National Aeronautics and Space Administration

Lewis Research Center

Cleveland, Ohio 44135

Lawrence Livermore Laboratory

University of California

P.O. Box 808

Livemore, California 94550

ii
ABSTRACT

The objective of this report is to:

1. provide all sponsoring agencies with a semiannual report on the

activities of their individual programs;

2. inform all sponsoring agencies on related research being conducted

at the NBS-NEL Themophysical Properties Division, NBS-NEL Mechanical

Processes Division and NBS-NML Fracture and Deformation Division;

3. provide a uniform reporting procedure which should maintain and

improve communication while minimizing the time, effort and

paperwork at the cost center level.

The work is supported by NBS and eight other agencies and represents the

collective expenditure of $619,000 during the 6-month reporting period. The

contents of this report augment quarterly progress meetings for certain of our sponsors and provide a perspective which is missing when the parts are viewed individually. Distribution of this document is limited and intended

primarily for the supporting agencies. Data or other information must be

considered preliminary, subject to change and unpublished, and therefore not

for citation in the open literature .

Key words: Cryogenics; liquefied natural gas; measurement; methane;

properties; research.
CONTENTS

Cost Center

I

.

REFERENCE DATA

a) THERMOPHYSICAL PROPERTIES DATA FOR PURE

COMPONENTS AND MIXTURES OF LNG COMPONENTS

(Gas Research Institute; American Gas

Association, Inc.; NASA Lewis Research

Center

)

7360574,

7360548

b) FLUID TRANSPORT PROPERTIES

(»!BS-Office of Standard Reference Data!

c) PROPERTIES OF CRYOGENIC FLUIDS ( NBS

)

7362290

7360122

7360124

7360125

d) PROPERTIES OF CRYOGENIC FLUID MIXTURES

(NBS; NBS-Office of Standard Reference

Data; Gas Research Institute)

7360123,

7362289,

7368574

e) DENSITIES OF LIQUEFIED NATURAL GAS MIXTURES

(LNG Density Project Steering Committee - AGA)

7361574

f) PROGRAM FOR REDUCING THE COST OF LNG SHIP 5621410,

HULL CONSTRUCTION — PHASE II SHIP STEEL 5621411,

IMPROVEMENT PROGRAM (Maritime

Administration)

g) MATERIALS FOR LNG APPLICATIONS (Gas

Research Institute)

7363574

h) LNG MATERIALS RESEARCH, CONCRETES

(Maritime Administration)

7360403,

6521511

II MEASUREMENT SCIENCE

a) CUSTODY TRANSFER - LNG SHIPS (Maritime

Administration; LNG Custody Transfer

Measurements Supervisory committee

7360460,

7361575,

7362575,

7363575,

7311573

HEATING VALUE OF FLOWING LNG (Pipeline

Research Committee - AGA)

7362570

c) LNG DENSITY REFERENCE SYSTEM (American Gas 7367574

Association, Inc.; Gas Research Institute

d) LNG SAMPLING MEASUREMENT STUDY (Pipeline 7363570

Research Committee - AGA)

III. TECHNOLOGY TRANSFER

a) SURVEY OF CURRENT LITERATURE ON LNG AND 7369574

METHANE (American Gas Association, Inc.;

Gas Research Institute)

Page

1

5

7

11

14

16

18

20

22

24

26

28

29

IV
CONTENTS (continued)

b) LIQUEFIED NATURAL GAS TECHNOLOGY TRANSFER 7360403,

(Maritime Administration; American Gas 7361403,

Association, Inc.; Gas Research Institute; 7364574,

NBS-Office of Standard Reference Data) 7368574,

7360127

c) OIML JOINT SECRETARIAT ON LNG MEASUREMENTS 7360290

(American Gas Association, Inc.; NBSOffice of International Standards;

NBS-Thermophysical Properties Division)

d) LNG SAFETY (Lawrence Livermore Laboratory) 7360450

Page

32

35

38

V
’
Title . THERMOPHYSICAL PROPERTIES DATA FOR PURE COMPONENTS AND MIXTURES

OF LNG COMPONENTS

Principal Investigators . R. D. Goodwin, H. M. Roder, G. C. Straty,

W. M. Haynes, R. D. McCarty, D. E. Diller, and B. A. Younglove

Cost Center Numbers . 7360574, 7360548

Sponsor Project Identification . Gas Research Institute Grant No.

5010-362-0019 and American Gas Association, Inc., Project BR-50-10.

National Aeronautics and Space Administration, Lewis Research Center,

Purchase Order C-78014-C.

Introduction . Accurate phase equilibrium, equation of state (PVT) , and

thermodynamic properties data are needed to design and optimize gas

separation and liquefaction processes and equipment, and for mass and

heat transfer calculations. Accurate data for the pure components and

selected mixtures of hydrocarbon systems will permit developing

comprehensive accurate predictive calculation methods which take into

account the dependence of the thermophysical properties of mixtures on the composition, temperature, and density.

This project will provide comprehensive accurate thermophysical

properties data and predictive calculation methods for compressed and

liquefied hydrocarbon gases and their mixtures to support the

development of LNG technology at NBS and throughout the fuel gas

industry. It will also serve as the base for a comprehensive mixtures

prediction methodology.

Objectives or Goals . The objectives of our work are the determination

of comprehensive accurate thermophysical properties data and predictive

calculation methods for the major pure components (methane, ethane,

propane, butanes, and nitrogen) and selected mixtures of liquefied

natural gas and hydrocarbon mixtures at temperatures between 80 K and

320 K and at pressures up to 35 MPa (5000 psi). Our goal is to provide

a range and quality of data that will be recognized as definitive or standard for all foreseeable low temperature engineering calculations.

Background . Liquefied natural gas is expected to supply an increasing

percentage of the United States' future energy requirements. It is

likely that massive quantities of liquefied natural gas will be imported

during the years 1978 - 1990. Ships and importation terminals are being

built for transporting, storing, and vaporizing liquefied natural gas

for distribution. Accurate physical and thermodynamic properties data

for compressed and liquefied natural gas and hydrocarbon mixtures are needed to support these projects. For example, accurate compressibility

and thermodynamic properties data are needed to design and optimize

liquefaction and transport processes; accurate data for the heating

value, which for liquefied natural gas mixtures depends on the total

volume, the density, and the composition, are needed to provide a basis

for equitable custody transfer. Accurate mixture data prediction

methods are needed for use in automated heat transfer calculations.

Accurate thermodynamic properties data for liquefied gas mixtures must

be based on precise compressibility and calorimetric measurements;

compressibility data give the dependence of thermodynamic properties on pressure and density (at fixed temperatures); calorimetric data give the

dependence of thermodynamic properties on temperature (at fixed

pressures and densities). It is impossible, however, to perform enough

compressibility and calorimetric measurements directly on multicomponent

mixtures to permit accurate interpolation of the data to arbitrary

compositions, temperatures and pressures. Instead, thermodynamic

properties data for multicomponent mixtures must usually be predicted
(extrapolated) from a limited number of measurements on the pure

components and their binary mixtures. This project was initiated to

provide the natural gas and aerospace industries with comprehensive

accurate data for pure compressed and liquefied methane, the most

abundant component in LNG mixtures. We have published National Bureau

of Standards Technical Note 653, "Thermophysical Properties of Methane,

From 90 to 500 K at Pressures to 700 Bar," by Robert D. Goodwin (April

1974), and National Bureau of Standards Technical Note 684, "Thermophysical Properties of Ethane, From 90 to 600 K at Pressures to 700 Bar," by

Robert D. Goodwin, H. M. Roder, and G. C. Straty (August 1976). These

reports contain the most comprehensive and accurate tables available for

the thermophysical properties of pure gaseous and liquid methane and

ethane, and provide an accurate basis for calculating thermophysical

properties data for LNG and other hydrocarbon mixtures.

7 . Program and Results .

7.1 Propane, PVTx and Dielectric Constant Measurements — W. M. Haynes

The defective coaxial lead to the capacitor (for dielectric constant

measurements) was replaced. However, there have been continuing

problems with a low temperature leak in one of the coaxial leads. It is

conjectured that this leak was caused by residual acid flux eating a hole in the thin-walled stainless steel sheath of one of the coaxial

cables. The leak does not show up at temperatures above 150 K. Therefore, measurements will be performed at temperatures above 150 K

before going to the low temperature regime.

After the higher temperature measurements are completed, the apparatus

will be disassembled and all coaxial leads will be replaced and

encapsulated in high-pressure stainless steel capillaries. This should

eliminate the leak problems that have occurred in the past with this

type of coaxial lead. This will add additional vapor volume to the

cell; however, this presents no problems for pure fluid measurements.

While the apparatus was apart, the design of the capacitor for

dielectric constant measurements was changed slightly. The outer

cylinder was fabricated into two halves with no slots except for where

the cylinder was split. The previous design incorporated the slots as a result of the mixture measurements. The split design allowed the

replacement of the coaxial lead without disassembling the guts of the

apparatus. It is hoped that this modification reduces the stray

capacitance

For the measurements in the higher temperature region, ethane will be

used as a control fluid in aligning the microscope for determination of

the position of the buoy. Ethane was chosen for use in this region for

several reasons. First, it has sufficient vapor pressure at

temperatures above 160 K so that it can be admitted to and removed from

the cell easily. Second, precise and accurate data for the density and

dielectric constant of saturated liquid ethane are available, most of

which were obtained in our laboratory.

At present, some measurements are being made on compressed gaseous

methane and nitrogen as further checks on the performance of the

capacitor for dielectric constant measurements. After a few

measurements on these fluids and tests on liquid ethane are completed,

measurements on liquid propane will commence again.

2
7.2

Calculational Methods — R. D. McCarty

Work is continuing on the extension and optimization of the corresponding states method to mixtures of methane with nitrogen and other

fluids. The transformation of the methane surface to N2 / O 2 / Ar

,

H 2 and C 2 H 4 has been the subject of thesis work by a graduate

student at the University of Colorado. The work is now complete and is

being published as a Masters thesis. We have determined that the

transformation function previously used for liquid density near saturation is inadequate for a broader range of pressure and

temperature. Efforts in finding a new function are continuing.

7.3

Propane, Specific Heat Data — R. D. Goodwin

This project is complete and the results published in "Specific Heats of

Saturated and Compressed Liquid Propane," by R. D. Goodwin, J. Res. Nat.

Bur. Stand. (U.S.) 83^, 449-58 (Sep-Oct 1978).

7.4 Normal Butane and Isobutane, Preliminary Thermophysical Properties

Data — R. D. Goodwin

The objective is to prepare provisional tables of thermodynamic

properties of normal and isobutane, using available physical properties

data. In this work we expect to discover those areas of properties data

most in need of further experimental measurements.

In general, there is an abundance of quite inconsistent data from

different laboratories, requiring tedious weightings, selections, and

eliminations. There are few data for liquid butanes at LNG

temperatures

.

Satisfactory formulations have been developed for the virial equation,

the saturated liquid densities, specific heats for the saturated liquid

below the boiling point, and for the ideal gas thermodynamic functions

for both fluids.

By thermal loops, in a procedure first developed by W. T. Ziegler, we have derived new "data" (where none existed) from the triple- to the

boiling-point for vapor pressures, densities of the saturated vapor, and

for heats of vaporization. The vapor-pressure equation has been

adjusted to include these new data, and a provisional description has

been developed for the heats of vaporization up to the critical point.

Manuscripts for reports on the equation of state and provisional tables

of thermodynamic properties for both n-butane and i-butane are complete.

The isobutane report is at the printer and the normal butane report is

in the final stages of editorial review. Both reports will be published

as NBS Interagency reports.

The work on isobutane was done sooner than planned because of a Department of Energy funded experimental project on that fluid which

will be used as a geothermal working fluid. The latter work is being

done at NBS-Gaithersburg and the two projects will be done on a collaborative basis so that the resulting 'final' tables will serve both

projects

.

7.5 Pure Nitrogen and Nitrogen-Methane PVTx Property Measurements —

G. C. Straty and D. E. Diller

All planned measurements and data analysis have been completed. A

report, PVT Properties of Nitrogen, has been submitted to the Journal of

3
Chemical Thermodynamics for publication. A second report, PVTx

Properties of Nitrogen-Methane Mixtures, is in editorial review and will

be submitted to the Journal of Chemical Thermodynamics for publication.

7.6 Sound Velocity of Propane — B. A. Younglove

Performance of the sound velocity measuring technique has proven

satisfactory. No changes in spacer length were required. We have

measured sound velocity of the saturated liquid at twenty temperatures

between 90 and 300 K. We have also made measurements of sound velocity,

temperature and pressure on isotherms at 200, 220, 240, 260, 280 and

300 K. The maximum pressure for these measurements 347 bar

(5000 psia)

.

The measured values of sound velocity have been compared to sound

velocity computed from the provisional thermodynamic properties of

propane. Deviations as large as 4% have been found.

The next measurements will be on the isotherms at 320 and 340 K followed

by a series on the isotherms from 90 to 180 K.

8. Problem Areas . None.

9. Level of Effort . January 1 - June 30, 1979.

Staff-years expended

Equipment and/or Services Purchased

Approximate expenditures, total

10 . Future Plans . Objectives and Schedule: Quarter

Optimize existing calculation

methods for the thermodynamic

properties of methane-nitrogen

mixtures and LNG mixtures.

1.1

10. 2K$

8 7 . 4K$ (75. 3K$-GRI

)

3 4

Measure, analyze and report PVT and

dielectric constant data for propane.

Publish provisional tables of thermodynamic properties for the butanes

and develop an accurate equation of

state

.

Measure, analyze and report sound

velocity data for propane.

Publish experimental results for

nitrogen and methane-nitrogen

mixtures

.

4
Title . FLUID transport properties

Principal Investigator . Howard J. M. Hanley

Cost Center Number. 7362290, 7362291

Sponsor Project Identification . NBS-Office of Standard Reference Data

Introduction . Methods for predicting the transport properties of fluid

mixtures are unreliable and data are scarce. Prediction methods are needed, however, to supply the necessary design data needed to increase

efficiency and reduce costs.

Objectives or Goals . The long range or continuing goal of the program

is to perform a systematic study of the theories and experimental

measurements relating to transport properties, specifically the

viscosity and thermal conductivity coefficients, of simple mixtures over

a wide range of experimental conditions. The specific objectives of the

program include: 1) the systematic correlation of the transport

properties of simple binary mixtures and the development of prediction

techniques, 2) development of a mixture theory for the dilute gas region

and the dense gas and liquid regions, 3) extension of the theory and

prediction techniques to multicomponent systems, and 4) suggested

guidelines for future areas of experimental work.

Background . A continuing program has successfully expanded the stateof-the-art of transport phenomena for pure fluids. Information for pure

fluids is required as a prerequisite for mixture studies. The theory of

transport phenomena has been developed and applied to produce practical

numerical tables of the viscosity, thermal conductivity and diffusion

coefficients of simple fluids: Ar, Kr, Xe , O F He, H

2

, CH^,^^

r h

(4) r h (5) l

2M 6' l 31‘

It has been shown that a successful mixture program can emerge from

combining the results for pure fluids with mixture equation of state

studies. The equation of state work is being carried out by other

investigators in this laboratory.

Program and Results . The transport properties of pure ethylene have

been computed’”' and a similar correlation of the properties of

hydrogen is near complet ion ' '

' . We continue to upgrade our mixture

prediction procedure reported previously

4

. The thermal

diffusivity of mixtures is of interest and work is in progress to

prepare a publication of the diffusivity of a methane/ethane mixture at

a gas/liquid critical point'^'.

Computer simulation of a binary mixture has been carried out, papers are

in the press

Problem Areas . The lack of suitable experimental mixture transport

properties data for comparison purposes is the main problem. Also

equation of state (PVT) data for mixtures are needed.

Level of Effort . January 1 - June 30, 1979.

Staff-years expended

Equipment and/or Services Purchased

Approximate expenditures, total

0.5

8 . 7K$

40. 5K$
10. Future Plans . The thrust of the effort for the next several months will

be to extend the computer simulation studies of mixtures. The studies

will yield information on the structure of the mixtures which will, in

time, lead to better methods to predict their properties.

References

1. H. J. M. Hanley, Prediction of the Viscosity and Thermal Conductivity

Coefficients of Mixtures, Cryogenics, Vol 16, No. 11, 643-51 (Nov 1976);

H. J. M. Hanley, Prediction of the Thermal Conductivity of Fluid

Mixtures, Proceedings 7th ASME Conf. on Thermophysical Properties;

H. J. M. Hanley in "Phase Equilibria and Fluid Properties in the

Chemical Industry," ACS Symp. Series No. 60 (1977).

2. B. J. Ackerson and H. J. M. Hanley (in preparation).

3. H. J. M. Hanley, W. M. Haynes and R. D. McCarty, The Viscosity and

Thermal Conductivity Coefficients for Dense Gaseous and Liquid Methane,

J. Phys. Chem. Ref. Data, Vol 6, No. 2, 597-609 (1977).

4. H. J. M. Hanley, K. E. Gubbins and S. Murad, A Correlation of the

Existing Viscosity and Thermal Conductivity Coefficients of Gaseous and

Liquid Ethane, J. Phys. Chem. Ref. Data, Vol 6, No. 4, 1167 (1977).

5. H. J. M. Hanley, P. M. Holland, K. E. Gubbins and J. M. Haile, J. Phys.

Chem. Ref. Data 8^, 559 (1979).

6. P. M. Holland and H. J. M. Hanley (in preparation).

7. L. Van Poolen, R. D. McCarty and H. J. M. Hanley (in preparation).

8. D. J. Evans and H. J. M. Hanley, Phys. Rev. A (1979) (in press).

6
1 . Title. PROPERTIES OF CRYOGENIC FLUIDS

Principal Investigators . G. C. Straty, N. A. Olien, B. A. Younglove,

H. M. Roder, and D. E. Diller

2 . Cost Center Numbers . 7360122, 7360124, 7360125

3. Sponsor Project Identification . NBS

4. Introduction . Accurate thermophysical properties data and predictive

calculation methods for cryogenic fluids are needed to support advanced

cryogenic technology projects. For example, liquefied natural gas is

expected to supply an increasing percentage of the United States' energy

requirements through 1990. Liquefaction plants, ships and receiving

terminals are being constructed to transport and store natural gas in

the liquid state (LNG). Accurate thermophysical properties data for LNG

are needed to design low temperature processes and equipment. Accurate

data will benefit the energy industries and the consumer by providing

for safe and efficient operations and reduced costs. We are now examining the data needs of a number of higher temperature industries

such as the synthetic natural gas (SNG) industry. This area of

technology as well as the liquefied petroleum gas (LPG) industry are logical extensions of the current LNG work. SNG mixtures can be

characterized as much more complex than natural gas, containing unlike

(including highly polar) molecules. Interactions between unlike

molecules are not well understood and the accurate data necessary to

quantitatively understand the interactions are lacking. The needs for

accurate predictive methods for SNG are essentially the same as LNG,

i.e., to reduce capital and operating costs and improve energy

efficiency.

5. Objectives or Goals . The objectives of this project are to provide

comprehensive accurate thermodynamic, electromagnetic and transport

properties data and calculation methods for technically important

compressed and liquefied gases (helium, hydrogen, oxygen, nitrogen,

methane, ethane, etc.) at low temperatures. In addition we intend to

develop the capability to perform accurate PVT measurements on gaseous

mixtures and pure components at high pressures and above room temperature. Precise compressibility, calorimetric and other physical

property measurements will be performed to fill gaps and reconcile

inconsistencies. Definitive interpolation functions, computer programs

and tables will be prepared for engineering calculations. The immediate

goals of this work are to obtain accurate sound velocity and thermal

diffusivity data for compressed and liquefied gases by using laser light

scattering spectroscopy techniques; design, construct and performance

test a precision PVT apparatus for the region 250 - 900 K with pressures

to 35 MPa; and design, construct and performance test a transient

hot-wire thermal conductivity apparatus for the region 70 - 350 K with

pressures to 80 MPa.

6. Background . The application of laser light scattering techniques to

obtaining thermophysical properties data was initiated to complement and

check other measurement methods and to solve measurement problems

inherent in more conventional methods. For example, laser light

scattering techniques permit measurements of sound velocities for fluids

under conditions for which sound absorption is too large to perform

ultrasonic measurements; laser light scattering techniques permit

measurements of thermal dif fusivities under conditions for which

convection interferes with measurements of thermal conduction. The

feasibility of light scattering experiments to obtain data on binary

diffusion coefficients has also been demonstrated.

7
Light scattering allows thermal diffusivity measurements in the region

where density fluctuations are relatively large, but accuracy drops

significantly as you pass outside the extended critical region. To

complement the scattering method, thermal conductivity measurements can

be made with more conventional techniques such as a hot-wire technique.

In the latter method a very small platinum wire is surrounded by the

fluid and a voltage pulse is applied to the wire. The temperature of

the wire is momentarily raised and the resistance increases. A series

of very closely spaced resistance measurements would describe the return

of the wire to equilibrium. These resistance vs. time measurements can

be related to the rate of heat dissipation in the surrounding fluid and

thus the thermal conductivity (provided convection heat transfer is

prevented )

.

The development of accurate mathematical models (equation of state) for

fluid mixtures requires accurate PVT data for the pure constituents and

binary mixtures of key molecular pairs. Experience with LNG has

identified the type and accuracy of the data required. In addition to

that, work on SNG at high temperatures is a logical follow-on to the low

temperature work on LNG. Typical constituents of raw SNG from coal via

the Lurgi process are: water - 50.2%; hydrogen - 20.1%; carbon

dioxide - 14.7%; carbon monoxide - 9.2%; methane - 4.7%; ethane - 0.5%;

hydrogen sulfide and others - 0.6%.

An apparatus has been assembled for laser light scattering spectroscopy

measurements on compressed and liquefied gases (76 - 300 K, 35 MPa).

The apparatus consists of a high pressure optical cell, a cryostat

refrigerated by means of liquid nitrogen, an argon ion laser and

low-level light detection equipment.

The light scattered from fluctuations in the fluid can be analyzed with

either digital autocorrelation techniques for the examination of the

very narrow lines associated with scattering from temperature

fluctuations (Rayleigh scattering) or with a scanned Fabry Perot

interferometer for the measurement of the Doppler frequency shifts

associated with the scattering from propagating density (pressure)

fluctuations (Brillouin scattering).

Apparatus for photon-counting and digital autocorrelation has been

assembled, interfaced with computer facilities and programmed to enable

on-line data accumulation and analysis. Initial problems associated

with signal modulations from excessive building vibrations have been

solved by levitating the apparatus on an air suspension system. A

small, highly stable capacitor has also been designed, constructed and

installed inside the scattering cell to permit the dielectric constant

of the scattering fluid to be determined, which should allow more accurate fluid densities to be obtained for use in the data analysis.

Apparatus tests on well characterized, strongly scattering, test fluids

have been made to verify data analysis programs.

Extensive thermal diffusivity data have been obtained for methane.

Measurements have been made along the. coexistence curve, the critical

isochore, and critical isotherm. The measurements extend outside the

critical region as well as deep into the critical region. In the deep

critical region the effect of temperature gradients and impurities have

been investigated. Outside the critical region, these effects do not

affect measurements beyond experimental accuracy. The range of the

measurements extends from 150 K to 230 K and 3 mol/L to 22 mol/L. The

inaccuracy of the measurements is about 5% in the critical region,

nalysis of the

reporting

the results has been submitted to the Journal of Chemical Physics.

increasing to 10% or greater further away. A detailed a data and experimental eTror has been made and a paper^'

8
Some preliminary results on a mixture of 70% methane and 30% ethane were obtained very near the vapor-liquid critical point (plait point). The

results are interesting in that the thermal conductivity of the mixture

does not exhibit a critical anomaly whereas pure methane does exhibit an anomaly in the thermal conductivity as the critical point is approached.

The anomalous behavior of pure fluids and nonanomalous behavior of

mixtures is qualitatively and quantitatively in agreement with theoretical predictions (see preceding title 'Fluid Transport Properties'). We

hope to be able to perform more definitive measurements on hydrocarbon

mixtures in the near future.

Program and Results .

7.1 Transient Hot-Wire Apparatus . The assembly of the apparatus is

complete and some preliminary measurements on air, nitrogen and helium

at low and moderate pressures and near room temperature have been made.

Experimental problems have persisted and the new apparatus is still not

functioning properly. For the most part computer problems have been

solved, but measured values for gas conductivity at low and moderate

pressures remain about 8% too high.

7.2 Laser Light Scattering Measurements . This project is inactive at

the present time.

7.3 High Temperature PVT Apparatus . Adequate funding for this program

was obtained in December 1978; as a result design, procurement and

construction will proceed at a level of effort of approximately 1.5

staff-years/year. Nearly all of the required equipment for the new PVT

apparatus has been received or is on order. This includes:

thermometers, thermometry bridge, desktop computer for experimental

control and data acquisition, pressure transducers, high temperature

ovens and high temperature pressure cell. The sample cells, thick-wall

stainless steel spheres, are nearing completion. During the next few

months assembly and checkout can begin. When completed this apparatus

and our existing PVT apparatus will give this laboratory the capability

of making precision measurements over the temperature range 10 - 1000 K

with pressures to 350 bar.

(7.4 Analyzing Gaseous Mixtures by Means of Raman Scattering . During

the past several months one of our staff members has worked on an experimental program at NBS-Gaithersburg. The objective was to explore

the use of Raman spectra in determining accurately the composition of

gaseous mixtures such as natural gas. Optical techniques offer the

possibility of analyzing gas and vapor compositions in situ. Tests were

run using a series of gravimetrically prepared mixtures such as methane-isobutane, methane-nitrogen and an LNG-like 8-component mixture.

The staff member has now returned to Boulder, but the preliminary

results are very encouraging. We plan a Raman capability in NBS Boulder

with the idea of using the principal to make precision determinations

of, for example, vapor phase compositions in complex liquid-vapor

systems

Problem Areas . Light scattering has proven to be a valuable tool for

obtaining thermal diffusivity data on fluids. This is particularly true

in a broad temperature and density range around the critical point,

where more conventional experimental methods fail or are severely

limited. The intensity of the scattered light however decreases

drastically as one moves away from the critical region. Data accuracy

in this region becomes limited by the statistical nature of the

scattering process and the ability to maintain stability and precise

experimental parameters over the extended periods of time necessary for

data accumulation.

9
We hope to hire a lj/jht scattering expert (experimentalist) in the next

few months to help resolve these problems as well as to explore other

optical techniques for fluid property studies.

The measurements using the hot-wire apparatus continue to be delayed

because of experimental problems.

9. Level of Effort . January 1 - June 30, 1979.

Staff-years expended

Equipment and/or Services Purchased

Approximate expenditures, total

1 0 . Future Plans . Objectives and Schedule: Quarter

Complete performance test transient

hot-wire thermal conductivity

apparatus

Design, construct and performance

test high temperature-high

pressure PVT apparatus.

2.1

2 7 . 2K$

153. 0K$

3 4

References

1. B. J. Ackerson and G. C. Straty, Rayleigh Scattering from Methane, J. Chem. Phys . 6j), 1207-12 (Aug 1978 ).

2. B. J. Ackerson and H. J. M. Hanley, The Thermal Diffusivity of Methane

in the Critical Region, Chem. Phys. Lett. 596-8 (Feb 1978).

10
1 . Title . PROPERTIES of cryogenic fluid mixtures

Principal Investigators . M. J. Hiza, A. J. Kidnay (part-time), and

R. C. Miller (part-time)

2. Cost Center Numbers . 7360123, 7362289, 7368574

3. Sponsor Project Identification . NBS, NBS (OSRD), Gas Research Institute

4. Introduction . Accurate thermodynamic properties data and prediction

methods for mixtures of cryogenic fluids are needed to design and

optimize low temperature processes and equipment. This project provides

new experimental measurements on equilibrium properties and compilations

of evaluated equilibrium properties data which are suitable for direct

technological use or for the evaluation of prediction methods.

5. Objectives or Goals . The overall objectives of this project are to

provide critically evaluated data on the phase equilibria and thermodynamic properties of cryogenic fluid mixtures. The program has been

divided into the following elements:

a) Preparation of a comprehensive bibliography on experimental

measurements of equilibrium properties for mixtures of selected

molecular species of principal interest in cryogenic technology.

b) Selection and/or development of methods for correlation, evaluation

and prediction of equilibrium properties data.

c) Retrieval and evaluation of experimental data for specific mixture

systems selected on the basis of theoretical and/or technological

importance

.

d) Preparation of guidelines for future research based on the

deficiencies noted in (a), (b), and (c).

e) Performing experimental research to alleviate deficiencies and

provide a basis for improvement of prediction methods.

6. Background A physical equilibria of mixtures research project was established in the Thermophysical Properties Division in 1959. The

initial effort, based on a bibliographic search and other considerations, was directed toward the acquisition of new experimental data on the solid-vapor and liquid-vapor equilibria and physical adsorption

properties for a limited number of binary and ternary mixtures of

components with widely separated critical temperatures. Most of the

systems studied included one of the light hydrocarbon species —

methane, ethane, or ethylene (ethene) — with one of the quantum

gases -- helium, hydrogen, or neon. The data for these systems led to

significant improvements in the predictions of physical adsorption

equilibrium and a correlation for the prediction of deviations from the

geometric mean rule for combining characteristic energy parameters. In

addition, significant new information was obtained for interaction third

virial coefficients which was used in a correlation by one of our consultants, J. M. Prausnitz. The approach taken in this work has been

as fundamental as possible with the intention of having an impact on a broad range of mixture problems.

Recent efforts have been directed toward problems associated with

systems containing components with overlapping liquid temperature

ranges, such as nitrogen + methane, methane + ethane, etc.

11
7. Program and Results . A summary of recent progress is as follows:

a) The paper^^ discussing compilation, evaluation, and

correlation of liquid-vapor equilibria data for methane + ethane

is in press.

b) A similar paper' ; discussing compilation, evaluation, and

correlation of liquid-vapor equilibria data for methane + propane

has been sent to the Office of Standard Reference Data for NBS

technical review.

c) Based on the work in (b), graphs of K-values and liquid-vapor phase

envelopes have been prepared for the second supplement of the LNG

Materials and Fluids Handbook.

d) Work on updating and expanding the bibliography' ' on equilibrium properties of fluid mixtures is well underway, though

this is no small task. In the original bibliographic effort, we attempted to include references for both saturated and unsaturated

hydrocarbons through the C 4

1

s but found that our coverage of

unsaturated C 4 hydrocarbons was very incomplete. Therefore, in our current effort we are including all saturated and unsaturated

hydrocarbons through C 3 , but only the saturated straight and

branch C 4 's and C 5 's (i.e., isobutane, normal butane,

isopentane, normal pentane, and neopentane). In addition to the

three pentanes, water is also being included which obviously adds a completely new dimension to our effort.

8 . Problem Areas . None

9. Level of Effort . January 1 - June 30, 1979

Staff-years expended

Equipment and/or Services Purchased

Approximate expenditures, total

1 0 . Future Plans . Objectives and Schedule: Quarter 3 4 Complete editorial review and prepare

final revision for publication of

paper reporting compilation, evaluation,

and correlation of liquid-vapor 7

equilibria data for methane + propane.

Continue update and expansion of

bibliography on equilibrium properties

of fluid mixtures.

References

1. M. J. Hiza, R. C. Miller, and A. J. Kidnay, A Review, Evaluation, and

Correlation of the Phase Equilibria, Heat of Mixing, and Change in

Volume on Mixing for Liquid Mixtures of Methane + Ethane. J. Phys . Chem.

Ref. Data, (3, No. 3 (1979). In press.

0.75

3 . 3K$

6 1 . 0K$ (12K$-GRI)

12
2. R. C. Miller, A. J. Kidnay, and M. J. Hiza, A Review, Evaluation, and

Correlation of the Phase Equilibria, Heat of Mixing, and Change in

Volume on Mixing for Liquid Mixtures of Methane + Propane, J. Phys.

Chem. Ref. Data (in review).

3. M. J. Hiza, A. J. Kidnay, and R. C. Miller, Equilibrium Properties of

Fluid Mixtures - A Bibliography of Data on Fluids of Cryogenic Interest,

NSRDS Bibliographic Series, IFI/Plenum, New York, 1975.

13
1. Title . DENSITIES OF LIQUEFIED NATURAL GAS MIXTURES

Principal Investigators . W. M. Haynes, R. D. McCarty and M. J. Hiza

2 . Cost Center Number . 7361574

3. Sponsor Project Identification . LNG Density Project Steering Committee,

American Gas Association, Inc., Project BR-50-11.

4. Introduction . Accurate density measurements and calculational methods

for liquefied natural gas mixtures are needed to provide a basis for

custody transfer agreements and for mass, density, and heating value

gauging throughout the fuel gas industry.

The basis for the custody transfer of natural gas is its heating value.

It is difficult to determine and agree on the heating value of extremely

large volumes of natural gas in the liquid state. For example, methods

for calculating the heating value of a liquefied natural gas mixture

require knowing its density, which in turn depends on its composition,

temperature, and pressure. As the compositions of LNG mixtures vary

considerably, depending on the sources of the gas and the processing

conditions, accurate methods are needed for calculating liquid densities

at arbitrary compositions, temperatures and pressures. The accuracy is

important because of the extremely large volumes of liquid involved.

5. Objectives or Goals . The objectives of this work are to perform

accurate ( 0 . 1 %) and precise ( 0 . 02 %) measurements of the densities of

saturated liquid methane, ethane, propane, butanes, nitrogen and their

mixtures mainly in the temperature range 105 - 140 K, and to test and

optimize mathematical models for calculating the densities of LNG

mixtures at arbitrary compositions and temperatures.

6 . Background . This project is being carried out at NBS because of the

realization that equitable custody transfer agreements could be reached more readily if the density measurements and the evaluation and

development of calculational methods were performed by independent

professionals

An apparatus incorporating a magnetic suspension technique has been

developed for absolute density measurements on liquids and liquid

mixtures, particularly at saturation, for temperatures between 90 and

300 K. The estimated imprecision of measurement is less than 0.02% and

the estimated inaccuracy is less than 0.15%.

7 . Program and Results .

7.1 Measurements . All measurements for this project have been

completed. The last series of measurements included the following:

(a) two methane-rich binary mixtures of CH 4 and iC^jHgQ/ (b) four

methane-rich binary mixtures of CH 4 and nC4Hio > and (c) seventeen

methane-rich multicomponent mixtures of LNG components, including five

7- and 8 -component mixtures containing up to 0.44% pentanes. The data

have been analyzed and comparisons of the experimental densities with

calculated values from mathematical models developed for predicting LNG

densities have been made.

Papers describing the apparatus, experimental procedures, and the data

and its analysis, from the last series of measurements are being

prepared for publications.

14
7.2 Calculat ional Methods . Final optimization on revision to all of

the models is now complete and two manuscripts are in preparation. The

final draft of the paper to appear in the Journal of Chemical

Thermodynamics is complete and in the review process. The preparation

of the NBS document which will contain computer code and detailed

instructions on their use is just beginning.

8. Problem Areas. None

10. Future Plans . This program is complete apart from the publication of

the final results. There are three experimental papers in preparation,

an apparatus paper, a paper detailing the performance of the predictive

models and a final report encompassing all results of this six year

project.

9. Level of Effort . January 1 - June 30, 1979

Staff-years expended

Equipment and/or Services Purchased

Approximate expenditures, total

0.1

5 . 0K$

5 . 0K$

15
1. Title . PROGRAM FOR REDUCING THE COST OF LNG SHIP HULL CONSTRUCTION -

PHASE II SHIP STEEL IMPROVEMENT PROGRAM

Principal Investigators . H. I. McHenry, M. B. Kasen and R. P. Reed

2. Cost Center Numbers . 5621410, 5621411

3. Sponsor Project Identification. Maritime Administration Misc. P.O.

400-58073

.

4. Introduction . Construction of LNG tankers requires the use of fine

grain normalized steels for the part of the hull structure that is

cooled by the cargo to temperatures in the range of 255 K (0°F) to 228 K (-50°F). Several ABS steels have satisfactory base plate properties but

extreme care must be exercised during welding to avoid degradation of

the steel adjacent to weld ( the heat affected zone) to a level of

toughness below U. S. Coast Guard requirements. Significant cost

problems are being encountered by U. S. Shipyards due to the resulting

inefficient low-heat-input weld procedures that must be employed to meet

the fracture requirements in the heat affected zone.

The feasibility of reducing the cost of LNG ship hull construction was investigated in Phase I of this project, leading to the Phase II program

described below.

5. Objective . The objectives of the Phase II program are 1) to have the

four major plate producers supply three LNG shipyards with production

heats of ABS steels modified to possess improved transverse fracture

properties at low temperatures, 2) to have the LNG shipyards evaluate

these plates by qualifying optimum welding procedures in accordance with

the USCG requirements and 3) to provide a metallurgical evaluation of

factors that influence heat affected zone toughness in the improved

steels.

6. Background. Early in 1974, the Welding Panel of MarAd's Ship Production

Committee recommended that a program be conducted to reduce the cost of

ship hull construction. NBS was requested by MarAd to propose such a program to the LNG subcommittee of the Welding Panel at a meeting in

Boulder in August. In mid-October, MarAd approved the initial phase of

NBS's recommended program, i.e., to survey the problem and the

technology available for its solution. On the basis of this survey and

as the result of a meeting of the Welding Panel in March, 1975, a coordinated program involving the LNG shipyards, the steel suppliers and

NBS was recommended to MarAd and to the Welding Panel. This program was approved and work started in May 1975. Cost-sharing contracts for the

evaluation of the improved steels were awarded in 1975 to the three

participating shipyards: Avondale shipyards, Inc., Newport News

Shipbuilding and Drydock Co. and General Dynamic s-Quincy Shipbuilding

Division. A similar contract was signed with Lukens Steel Co. to evaluate Cb-treated V-051 steel with and without sulfide shape control.

The three participating shipyards and Lukens Steel Co. completed the

shipyard evaluation phase of the program in 1977. The ABS steels with

sulfide shape control had excellent toughness and the HA Z toughnes was improved, particularly for shielded metal arc (SMA) and gas metal arc (GMA) welds. The most promising results for high-heat-input welds were obtained with the Cb-treated V-051 steel with sulfide shape control.

Follow-on contracts were awarded to the three participating shipyards to further evaluate the most promising ship steels: ABS grades V-051

16
(Cb, SSC), V-062 (SSC) and (Cb, SSC). The work on these contracts has

been completed. The results Indicate that each of the steels retains

satisfactory HAZ toughness at -51 U C (at higher heat inputs than

conventionally used) providing the weld metal toughness exceeds the 27J

(20 ft. lb.) minimum.

7. Program and Results . During this reporting period, no additional

research was conducted. A presentation of the program results was given

at the AWS/MarAd Conference on Welding in Shipbuilding: Productivity

and Economic s

8. Problem Areas . The completion of the evaluation of Ml-88 wire was delayed due to other shipyard commitments.

9. Level of Effort . January 1 to June 30, 1979.

Staff years expended 0.1

Approximate expenditures, total $2K

10.

Future Plans . An evaluation by Avondale Shipyards Incorporated of

submerged arc weldments with Linde Ml-88 wire will be completed. Upon

completion, the final report on the program will be finished.

17
i. Title. MATERIALS FOR LNG APPLICATIONS

Principa l Investigators . L. L. Sparks

2. Cost Center Number. 7363574

3. Sponsor Project Identification. Gas Research Institute Grant Number

5014-361-0131

.

4. Introduction . Safe, economical storage and transportation of LNG

depend to a large extend on the materials used in the construction of

capital equipment, i.e., ships, storage facilities, transfer terminals,

liquefiers, and pipelines. Thermal insulations constitute a critical

link in the materials for use in LNG oriented energy efforts because of

the cryogenic nature of the liquid.

Expanded plastics (foams) are being used or are being considered for use

in facilities such as these. Low-temperature properties data,

standardized cryogenic test methods, and standard reference materials

are not presently adequate to meet the needs of complicated insulation

systems. These materials are anisotropic for most properties so that

properties data must be accompanied by specimen characterization in

order to be of general use. Standard reference materials, for use in

checking experimental systems are completely lacking. With the exception of thermal conductivity, standardized test methods for lowtemperature testing of foams are also completely lacking.

5. Objectives or Goals. The broad objectives of this project are twofold:

first, provide the users of thermally insulating foams with basic

knowledge about the behavior of expanded plastics at cryogenic temperatures and methodology to allow experimental determination of the properties of specific materials; second, serve as a center of insulation

material information for GRI and associated users of cryogenic fuels.

The first objective will be achieved by determining the low-temperature

thermal and mechanical properties of selected, well characterized foams.

The methodology of testing at low temperatures and characterizing the

test materials will be stressed. The second objective will result as a consequence of this research effort.

6. Background. The The rmo phy s i ca 1 Properties Division, previously known as the Cryogenics Division, has been involved in the development and

application of cryogenic insulations since being established in 1951.

The Properties of Solids group at Boulder has successfully examined the

thermal and mechanical properties of a wide variety of materials:

metals, polymers, insulations, and composites. The group, as a whole,

has the equipment and expertise to establish and perform cryogenic tests

to determine the mechanical and thermal properties of foams. Close

working relationships with private companies, universities, and

professional associations provide guidance in the areas of material

selection, quality control, and standardization of materials and

methods

.

The groundwork for the current foams research was done while working on the Insulation Section of the LNG Materials Handbook (funded by Maritime

Administration)

.

18
Program and Results. The program designed to meet the need for lowtemperature data and standards for expanded plastics includes the

following items: assessment of materials, assessment of methods,

specimen acquisition, specimen characterization, and testing. A continuing survey of the open literature and contacts with many foam

related companies are being used to assess materials and methods.

The cooperation of users, producers, standardization societies, and

other government labs, is extremely important to the success of the

program. It is being stressed, particularly with the producers, that

this program is not intended to do their research for them; out results

will be related to identifiable characteristics such as general type of

foam, cell size, membrane thickness, manufacturing process, etc.

Property dependence on these parameters can be related to new as well as existing products.

Test procedures which have been used are being determined and evaluated.

This information along with past experience at NBS-Boulder in cryogenic

testing of foams, is being used to establish the initial procedures for

this program. Evaluations of these procedures over the duration may

lead to extensions and modifications of existing standardized methods to include the cryogenic temperature range.

The characterization of materials will be accomplished by utilizing both

inhouse capabilities and that of other government laboratories.

Acquisition of equipment which will allow inhouse capability to be

developed is being considered; the possibility of i n t e r 1 aba t o r y equipment loans and purchase with general purpose equipment funds are being

studied. The procedures, time required, cost, etc. for analysis at

other government laboratories are being determined.

The ASTM sanctioned thermal conductivity, , systems are available: a guarded hot plate system, capable of testing from 77 to 1270K has

undergone modifications and is now in the checkout stage. The second

system is a boil-off calorimeter which allows a number of parameters to be varied while is being determined. Activation of this system is in

progress . Several designs for a general purpose thermal expansion, , system are being considered. Inhomogeneous, anisotropic materials such as foams,

aggregates, and fiber-matrix composites require large diameter

geometries. Modification of an existing system or design and

construction of a new one will be jointly funded by several projects.

Problem Areas. None.

Level of Effort. January 1 - June 30,

Staff years expended

Equipment and/or Services purchased

Approximate Expenditures, Total

1979

0 .04

0 $2,800

Future Plans . The assessment phases will continue. Although actual

specimen acquisition will not begin until the material assessment phase

is completed, the sources and procedures are being developed now. The

characterization and testing a particular foam will begin in the next

reporting period. The thermal expansion system will be completed and

the activation of the boil-off calorimeter system will continue.

19
1. Title . LNG MATERIALS RESEARCH, CONCRETES

Principal Investigators . L. L. Sparks and M. B. Kasen

2 . Cost Center Number . 7360403, 5621511

3. Sponsor Project Identification . Maritime Administration, Miscellaneous

Purchasing Order No. 400-89019.

4. Introduction . Concretes are attractive materials for construction of

large LNG installations because of lower material cost and economies of

fabrications compared to alternative construction methods. They exhibit

favorable mechanical and thermal properties for use in LNG applications.

Although these materials are presently used to some extent in LNG con- struction, lack of confidence in their cryogenic behavior has restricted

their use to noncritical components or has resulted in overly conservative and expensive designs. This reflects the lack of dependable cryogenic thermal and mechanical properties data and a poor understanding of

the effect of field fabrication variables on cryogenic performance.

Applications of special concretes such as lightweight, cellular, fiber

reinforced, and polymer will depend on their cryogenic properties, which

are unknown at this time. The experimental program to determine these

properties will be executed in cooperation with the USCG, Portland

Cement Association (PCA), and private corporations such as Global

Marine, Concrete Technology, and Preload Technology.

5. Objectives or Goals . The program objectives are to determine the low

temperature (76K _< T _< 300K) properties of concretes which are presently

being used in LNG applications and those which may provide design alternatives in the future. The properties which may be determined include:

thermal conductivity, Young's modulus, thermal expansion, compressive

strength, fatigue strength, splitting strength, permeability to water

and LNG, and thermal shock. The dependence of these properties on parameters such as moisture content, air content, water-to-cement ratio,

additives, aggregate type and grade, and aging will be determined. The

parameter dependencies will be studied in order to understand the fundamental basis for the cause/effect relationships which are observed.

Specimen characterization and parameter control are extremly important

to this phase of the program. Knowledge gained from the parameter

dependencies will be used to assess variabilities found in field-erected

structures. This information is needed to establish the quality control

necessary to assure fitness-for- service in cryogenic applications. The

testing procedures which are used must produce reproducible and accurate

data. With the exception of thermal conductivity tests, there are no standardized procedures for testing concretes at cryogenic temperatures.

The large variations found in the literature are due, in part, to this

deficiency. Whenever possible, ASTM, and ACI procedures, modified to accommodate the cryogenic environment, will be used throughout this

program

6. Background. The initial involvement of the Cryogenics Division in the use of concretes as low temperature structural materials was in 1973.

Safety aspects of concrete, cryogenic installations were stressed. Data

from the literature were collected and used in these safety evaluations;

it became very clear that reliable cryogenic data, basic cause/effect

relationships, and standardized cryogenic experimental procedures were inadequate. The situation has not changed significantly, as was determined in a thorough literature evaluation of concrete at cryogenic temperatures (LNG Materials Handbook, second supplement, funded by MarAd).

20
The Properties of Solids group at NBS-Boulder has successfully examined

the thermal and mechanical properties of a wide variety of materials:

metals, polymers, insulations, and composites. The group, as a whole,

has the equipment and expertise to perform cryogenic tests to determine

the mechanical and thermal properties of concretes. Close working

relationships with private companies, universities, and professional

associations provide guidance in the areas of material selection and

quality control of f iel d- e r e c t ed structures.

7. Program and Results. The specimens to be used for determining the

compressive strength have been obtained; the chemical composition of the

cement and the composition and size distribution of the aggregates have

been determined.

The system needed to measure the thermal contration of these inhomogeneous materials is being designed. Special considerations for this

apparatus include the capability to accommodate large diameter specimens

(necessary in the case of inhomogeneous materials such as concrete.

Two systems will be utilized to determine the thermal conductivity of

concretes. One of these systems is operational while the other is being

reactivated.

Specific test procedures are being studied for determination of each of

the above properties. It is our goal to develop low-temperature

procedures which not only produce accurate results in our tests, but can

be adopted by other laboratories.

8. Problem Areas . None.

9. Level of Effort . January 1 - January 30, 1979

Staff years expended 0.04

Equipment and/or services purchased none Approximate Expenditures, Total $4,500

10. Future Plans. Low-temperature compressive strength tests will be

completed for the initial concrete mix. Methods of determining the

compressive stress-strain relationship will be evaluated.

Design and construction of the system necessary to measure the thermal

contraction will continue. Reactivation of the guarded cold plate

calorimeter for determining thermal conductivity will continue. The

initial thermal conductivity measurements will be made using the smaller

guarded hot plate system which is operational at this time.

21
1 . Title. CUSTODY TRANSFER - LNG SHIPS

Principal Investigators . W. C. Haight, R. J. Hocken, B. R. Borchardt,

R. G. Hartsock, R. C. Veale, J. D. Siegwarth, J. F. LaBrecque, C. L. Carroll, C. P. Reeve, and F. E. Scire

2. Cost Center Numbers. 7360460, 7361575, 7362575, 7363575, 7311573,

7311577

3. Sponsor Project Identification . LNG Custody Transfer Measurements

Supervisory Committee and Maritime Administration Misc. P.O.

#400-79005.

4. Introduction . In response to the requests from the U.S. shipbuilding

industry, NBS is independently examining the accuracies of LNG tank

cargo capacity tables and developing alternative survey techniques.

5. Objectives . The objectives of the program are to develop new techniques

for LNG transport tank calibration and to test the accuracy of present

calibration techniques as part of an overall study of custody transfer

methods aimed at increasing the accuracy of custody transfer

measurements

.

6. Background . Initial funding by the Maritime Administration (7360460)

supported some preliminary tests of calibration of spherical LNG ship

tanks. As a result of these measurements, the LNG Custody Transfer

Supervisory Committee and the Maritime Administration have funded

extension of the work to the membrane tanks and the free standing

prismatic tanks now under construction in U.S. shipyards.

7. Program . The NBS measurements of volume of the membrane tanks of all t three of the U.S. built El Paso LNG ships have been completed. The NBS

determined volume - height relationships for the tanks of the first ship

agree with those determined by the primary surveyor to better than 0.2%

of total volume. Calibration report have been issued for all tanks of

the first ship. Calibration reports on the results of the NBS

measurements of the tanks of the remaining two ships are in

preparation.

The photogrammetr ic measurements of the 15 free standing prismatic tanks

for the three ships are now completed. A completely independent survey

of tank #3 of the third ship has been completed. This tank was also

surveyed during the hydrostatic testing to investigate the effect of

hydrostatic loading on the tank volume. The dead wood correction, i.e.,

the removal of volume of aluminum included within the calibrated volume

has been examined in detail on this tank. A preliminary report on the

volume uncertainty of the tank of the first ship has been supplied to

the owner. The tank orientations and bottoms have been surveyed on the

first two ships.

8.

Problem Areas. None

9. Level of Effort . January

Staff years expended

Equipment and/or services

Approximate expenditures.

1 - June 30,

purchased

total

1979

1.5

37 K

$

91 K $

22
10 „ Future Plans . Measurements of the orientation and bottom surveys of

the tanks of the El Paso Columbia remain to be done. Tank calibration

report on the remaining two membrane tank ships and the preliminary

uncertainty report on the final two ships with free standing prismatic

tanks will be completed.- The results of the additional surveys on the

free standing tanks will be documented and a final report issued on the

tank calibration and the photogrammetr ic methods.

23
1 . Title , heating value of flowing lng

Principal Investigators . J. A. Brennan

2. Cost Center Number . 7362570

3. Sponsor Project Identification . Pipeline Research Committee (American

Gas Association) PR-50-48.

4. Introduction . This project will test instrumentation for making heat

value measurements on flowing LNG in actual applications. Information

from projects currently underway by Siegwarth (cost center 7367574) on densimeters, by Haynes and Hiza (cost center 7361574) on mixture

densities and by Richards (cost center 7363570) on LNG sampling will be

utilized where appropriate to provide state of the art information.

5. Objectives . The objective of this project is to measure total heating

value of LNG flowing in a pipeline by the integration of individual

measurements of flow, density and specific heating value. Flow

measurement requires determination of flowmeter performance in line

sizes larger than are presently available in operating calibration

facilities. Therefore, a secondary objective is to establish

appropriate flowmeter scaling laws.

6. Background . The LNG flow facility at NBS was used to evaluate the

response and integration of the individual elements of the heating value

measurement. Different compositions of LNG were tested to provide a range of densities and temperatures sufficient to determine any

dependencies. Sampling work was combined with the sampling project

(cost center 7363570) to better define the important criteria of this

phase of the measurement problem.

Flowmeter scaling work utilizes the cryogenic and water flow facilities

at NBS as well as private LNG peak shaving and import facilities.

7. Program and Results . On three different occasions LNG flowmeter tests were run at Southern Energy Company's import terminal. These tests

covered a range of flow rates from 88.5 m^/s (270 x 10^ SCFD) to

140.9 m^/s (430 x 10^ SCFD). During a portion of each test, there were intervals during which the signal from the flowmeter measuring the

LNG flow was of very poor quality and resulted in poor agreement between

the liquid and gas flow meausrements . Attempts to isolate this problem

by changing electronic components was not successful.

When the flowmeter signal was of good quality, the agreement between the

liquid and gas flow measurements was very good. During all of these

tests, when the flowmeters were operating correctly, the agreement

between the two measurements was within the uncertainty of the gas flow

measurement alone.

Densimeter tests were also run during the flowmeter tests. It was necessary to change some of the electronic components before the

densimeter would operate consistently. These changes were completed

during the second test and appeared to correct the problem. Data from

the densimeter is still being analyzed and will be included in the next

report.

At the present time, no additional testing is planned.

24
8 . Problem Areas . None

9. Level of Effort. January 1 - June 30, 1979

Staff years expended 0.2

Equipment and/or services purchased none Approximate Expenditures, Total $9031.00

25
1* Tit le , lng density reference system

Principal Investigators . J. D. Siegwarth and J. F. LaBrecque

2 . Cost Center Number . 7367574

3. Sponsor Project Identification . American Gas Association, Inc., Project

BR-50-10; National Bureau of Standards, Gas Research Institute.

4. Introduction . A density reference system has been developed to evaluate

the ability of commercially available instruments to measure densities

of LNG directly. Density is an essential measurement in determining the

total energy content of natural gas reservoirs.

5. Objectives . The object of this research is to develop and supply

adequate calibration methods and calibration standards to densimeter

manufacturers and users for providing traceability of accuracy to field

density measurement systems.

Background . The density reference system project was initiated in 1973.

Since that time the reference system has been designed, constructed, and

is now in operation, evaluating commercial density metering systems.

Reports describing the density reference system and the results of the

tests of four commercial densimeters have been published. These reports

are

Siegwarth, J. D. , Younglove, B. A., and LaBrecque, J. F. , Cryogenic

fluids density reference system: provisional accuracy statement.

National Bureau of Standards (U.S.) Technical Note 698, 24 pages (1977),

and

Siegwarth, J. D. , Younglove, B. A., and LaBrecque, J. F. , An evaluation

of commercial densimeters for use in LNG, National Bureau of Standards.

(U.S.) Technical Note 697, 43 pages (1977).

The work has also been presented in the following papers:

Siegwarth, J. D. , Younglove, B. A., and LaBrecque, J. F. , Test of

densimeters for use in custody transfer of LNG, Proc 53rd International

School of Hydrocarbon Measurement, Normon, Oklahoma (1978).

Parrish, W. R. , Brennan, J. A., and Siegwarth, J. D. , LNG custody

transfer research at National Bureau of Standards, American Gas

Association Operating Section Proc. T243 (1978).

The rebuild of the DRS has been completed and test work on three

displacement type densimeters and a vibrating cylinder densimeter is

underway. The sample holder can now be cooled and filled in about two

ours, the temperature differences between top and bottom thermometers

can be held below .020 K during the measurements with little difficulty

without using the stirrer running at low speed. In fact, it is possible

to obtain this degree of isothermal condition at various temperatures

without using the stirrer at any time.

Three other vibrating cylinder densimeters are on hand to be tested or calibrated.

A prototype portable standard using a more compact electronic balance

and a silicon single crystal has been designed and is under construction.

26
A calibration method for displacement type densimeters, using pure

methane and a methane-propane-nitrogen mixture, is being tested.

Preliminary results indicate the method will adequately calibrate

densimeters.

The results of the vibrating cylinder densimeter tests to date show the

calibration of the densimeter is particularly sensitive to sample

composition

.

8. Problem Areas . The DRS densimeter readings are shifted about. 0.05%

relative to the density readings prior to the rebuild of the DRS

according to the density determined from the average sample temperature.

This systematic difference probably arises from a peculiarity in the

electronic balance. This problem will be examined further when the DRS

densimeter using the compact balance is operational.

9. Level of Effort . January 1 - June 30, 1979

Staff Years Expended 0.4

Equipment and/or Services purchased $ 8,000

Approximate Expenditures $30,000

10. Future Plans . The DRS densimeter using the compact electronic balance

will be completed and tested as soon as evaluation of the densimeters

presently under test are completed. Besides calibrating two more vibrating cylinder densimeters for transfer standards, a vibrating plate

densimeter will also be calibrated as a transfer standard. Arrangements

are underway to do additional tests of a capacitance type densimeter.

27
1 . Title . LNG sampling measurement study

Principal Investigators . R. J. Richards, J. F. LaBrecque, and J. A. Brennan

2. Cost Center Numbers . 7363570

3. Sponsor Project Identification . Pipeline Research Committee (American

Gas Association) PR-50-94.

4. Introduction . Composition is used to determine both the heating value

and the quantity (through density) of LNG shipments. Thus, any error in

composition doubles when calculating the total heating value and dollar

value of a LNG tanker cargo. Compositions are determined by sampling

LNG, on either a batch or continuous basis, and analyzing the vaporized

mixture. Although several sampling techniques exist, none have received

a widespread acceptance in the LNG industry. Also, a standard technique

has not been established for analyzing the vaporized sample.

5. Objectives . The objective of this project is to expand the work

previously completed on the NBS LNG sampling system. This new work will

investigate new vaporizer designs and test variations in accumulator

size requirements. The goal is to obtain information necessary for

design purposes.

6. Background . This work was performed because there is a need to

determine the best means for obtaining the composition of LNG shipments.

Current LNG buying contracts include specifications on when and how many

liquid samples are to be taken but omit the sampling technique to be

used. The evaluation of sampling techniques by NBS is expected to lead

to the acceptance of the most accurate composition determination method

by all parties involved in LNG custody ttansfer.

7. Program and Results . As stated in the last report, the final testing on this project was to be on accumulators of various sizes. This was to be

done in an effort to reduce the size of the accumulator so that the

system time constant could be as short as possible. These tests were completed using six different size accumulators ranging from 0.1 to 4.8

liters. No detectable difference in performance was observed with

accumulators with volumes of 1.7 liters or larger. There did appear to

be a significant decrease in precision while using accumulators with

volume of 0.1 and 0.2 liters, however.

This work is now complete and a final report has been drafted.

8. Problem Areas . None.

9. Level of Effort . January 1 - June 30, 1979

Staff years expended 0.4

Equipment and/or services purchased none Approximate Expenditures, Total $17,250.00

28
1. Title . SURVEY OF CURRENT LITERATURE ON LN6 AND METHANE

Principal Investigator . Neil A. Olien

2. Cost Center Number . 7369574

3. Sponsor Project Identification . Gas Research Institute Grant No.

5010-362-0019 and American Gas Association, Inc., Project BR-50-10.

4. Introduction . It is important that all NBS personnel working in LNG , as well as the AGA and others, keep up with what is going on throughout the

world in the LNG field. This project is designed to provide the Current

Awareness and other information services to allow workers to keep

abreast of new research and other developments.

5. Objectives or Goals . We will publish and distribute each April, July,

October, and January a listing of all significant papers, reports, and

patents relating to methane and LNG properties and technology. The

references will be listed under convenient subject headings. The

Quarterly will be distributed to all interested AGA member companies and

be made available to the general public on a subscription basis. In

addition, LNG-related information will be entered into the Cryogenic

Data Center's Information System for quick retrieval. A systematic

review of the current publication scene is maintained for any new periodicals to be reviewed cover- to-cover . Finally we will update and

make available comprehensive bibliographies on the properties and

technology of LNG. There are four bibliographies involved: methane

properties, methane mixtures properties, processes and equipment

involving methane and LNG, and patents relating to methane and LNG

technology. These four will be updated annually.

6. Background . In 1969 we made a thorough review of the world's publications to determine which periodicals and abstracting services should be

scanned cover- to-cover to adequately encompass the LNG field. The

result is that we now scan over 330 primary publications and nearly 25

secondary publications. Of these, approximately one-third are directly

related to LNG. In addition, we have increased our coverage of the

energy field to include SNG (coal gas, hydrogen, etc.). Much of this

information is also pertinent to LNG and as such is listed in our LNG-related publications. Our Current Awareness Service has been

published weekly since 1964 (beginning in 1975 the publication became

biweekly) and the Liquefied Natural Gas Survey has been published

quarterly since 1970.

7. Program and Results . Four issues of the LNG Quarterly are prepared each

year and distributed. There are now 137 subscriptions going to AGA

Member Companies and 159 to other subscribers.

The four comprehensive bibliographies mentioned in section 5 have been

reviewed and shortened, and more selective bibliographies have resulted.

The latest versions were completed as of January 21, 1977.

B-1525 THE THERMOPHYSICAL PROPERTIES OF METHANE AND DEUTERO-METHANE

IN THE SOLID, LIQUID AND GASEOUS PHASES - A SELECTED BIBLIOGRAPHY. Indexed by property, phase and author, 100 pages

(Jan 1977) . ($10.00)

B-1526 THE THERMOPHYSICAL PROPERTIES OF METHANE MIXTURES - A SELECTED

BIBLIOGRAPHY. Indexed by property, system and author,

166 pages (Jan 1977). ($15.00).

29
B-1524 PROCESSES AND EQUIPMENT INVOLVING LIQUEFIED NATURAL GAS AND

METHANE - A SELECTED BIBLIOGRAPHY. Indexed by subject and

author, 285 pages (Jan 1977). ($25.00).

B-1527 PATENTS RELATING TO METHANE AND LNG TECHNOLOGY - A SELECTED

BIBLIOGRAPHY. Indexed by author, 150 pages (Jan 1977).

($15.00)

.

Over the past seven years we have distributed over 500 copies of these

and the comprehensive bibliographies.

The size of these has grown to the extent that their usefulness is

limited, therefore it was decided that they would not be updated and a series of more specialized bibliographies would be made available. The

following list gives those currently available. Additional topics will

be added as necessary.

B-1528 LIQUEFIED NATURAL GAS STORAGE INCLUDING INSULATION SYSTEMS.

1181 references, indexed by author and subject, 210 pages

($20.00)

.

B-1529 LIQUEFIED NATURAL GAS PEAKSHAVING AND SATELLITE OPERATIONS.

221 references, indexed by author, 36 pages ($10.00).

B-1530 LIQUEFIED NATURAL GAS STRATIFICATION AND ROLLOVER. 38

references, indexed by author and subject, 10 pages ($5.00).

B-1531 LIQUEFIED NATURAL GAS SAFETY INCLUDING SPILLS. 368

references, indexed by author and subject, 72 pages ($10.00).

B-1532 LIQUEFIED NATURAL GAS PIPELINES AND TRANSFER LINES. 226

references, indexed by author, 44 pages ($10.00).

B-1533 LIQUEFIED NATURAL GAS SHIPS, BARGES AND OVERWATER TRANSPORTATION. 805 references, indexed by author, 138 pages ($15.00).

B-1534 LIQUEFIED NATURAL GAS VAPORIZORS INCLUDING COLD UTILIZATION.

330 references, indexed by author and subject, 58 pages

($10.00) . B-1535 LIQUEFIED NATURAL GAS HEAT TRANSFER. 155 references, indexed

by author, 34 pages ($10.00).

B-1536 LIQUEFIED NATURAL GAS LIQUEFACTION AND REFRIGERATION. 551

references, indexed by author, 94 pages ($15.00).

B-1537 LIQUEFIED NATURAL GAS ECONOMIC FACTORS. 470 references,

indexed by author, 84 pages ($15. 00).

B-1538 LIQUEFIED NATURAL GAS OVERLAND TRANSPORTATION. 76 references,

indexed by author, 15 pages ($5.00).

B- 1539 LIQUEFIED NATURAL GAS PATENTS. 747 references, indexed by

author and subject, 119 pages ($15.00).

B-1540 LIQUEFIED NATURAL GAS INSTRUMENTATION. 85 references, indexed

by author and subject, 23 pages ($5.00).

The above thirteen bibliographies are in the process of being updated

and will be available in August.

Problem Areas. None.

30
9. Level of Effort . July 1 - December 31, 1978.

0.25

2. 2K$

7 . 5K$

Staff-years expended

Equipment and/or Services Purchased

Approximate expenditures, total

10. Future Plans . Issue 78-4 was delivered to the printer the second week

of January and should be distributed before the end of January.
1 . Title. LIQUEFIED NATURAL GAS TECHNOLOGY TRANSFER

Principal Investigators . D. E. Diller, H. M. Ledbetter, L. L. Sparks,

and N. A. Olien

2. Cost Center Numbers. 7360403, 7361403, 7364574, 7368574, 7360127,

7360461, 7360594

3. Sponsor Project Identification . Maritime Administration, Miscellaneous

Purchase Order No. 400-79005; American Gas Association, Inc. Project

BR-50-10 ; Gas Research Institute; NBS Office of Standard Reference

Data.

4. I ntroduct ion . The liquefied natural gas program at the Thermophysical

Properties Division of NBS Boulder represents an investment by industry

and government agencies of over $7 million over the past six years.

This investment was designed to develop reference quality properties

data for both fluids and materials and instrumentation and measurement

technology for the use of the LNG and related industries. Information

developed under this program must be transmitted to the ultimate user in

a timely and useful format. The classical publication methods of NBS

most certainly provide the scientist and research engineer information

in a form most useful to the academic or near academic community.

However, as a result of extensive assessments of user requirements, it was found that an additional effective mode for technology transfer

would be an LNG Materials and Fluids User's Manual. A complete outline

and planned table of contents have appeared in previous semiannual

reports. The Maritime Administration of the Department of Commerce and

the American Bureau of Shipping agreeded to sponsor the first year's

efforts on the materials section, and the American Gas Association, Inc.

and the NBS Office of Standard Reference Data agreeded to sponsor the

section on fluids and fluid mixtures. The project was begun on April 1,

1976.

5. Objectives or Goals . The Liquefied Natural Gas Materials and Fluids

User's Manual will provide a method of quick dissemination of property

data and related information for the effective generation, utilization

and transportation of LNG. The object is to improve technology transfer

from the current NBS Thermophysical Properties Division LNG physical

measurements program to the users, including federal agencies, the

states and industry. For the purpose of this data book, liquefied

natural gas is defined as a cryogenic mixture (at less than

approximately 150 K) of hydrocarbons, predominantly methane, with less

than a total of 20% of the minor components ethane, propane, iso and

normal butane, and nitrogen as an inert contaminant. LNG materials will

be those associated with the liquefaction, transport and storage of

liquefied natural gas.

6. Background . The User's Manual is only one of a number of information

dissemination methods used to provide workers in the liquefied natural

gas (LNG) industry with properties data of known quality in a format

consistent with the requirements of the intended user. In the case of

the LNG User's Manual the intended audience is the field engineer, plant

manager, ship designer or process engineer interested in a ready

reference of assessed quality for data to be used in conceptual design,

process monitoring, process analysis, and intercomparisons where

precision and accuracy are secondary to specific problem solutions. The

hierarchy of accuracy and precision will be defined and traceable

through references to scientific and engineering literature.

Data are classified into three groups by the NBS Thermophysical

Properties Division.

32
Group 1 . Data which have been generated experimentally by NBS , or have

been assessed, evaluated or experimentally verified by NBS.

Group 2 . Data which have been assessed and evaluated by NBS.

Group 3 . Data available in the scientific engineering literature

through the NBS Cryogenic Data Center or elsewhere. No NBS evaluation

or assessment has been made at this date.

In general, most data included in the LNG User's Manual will be from

groups 1 and 2. Few new assessments or correlations are anticipated or required for this work.

Data will be presented primarily in graphical form. Tables and analytical expressions will be used only where absolutely necessary. Graphs

and charts will be in loose-leaf form for ease of updating and

additions. This form will also allow immediate implementation for data

already available under the NBS LNG program and will provide a convenient format for the output of data from existing projects. The

User's Manual will not be a substitute for traditional publications in

the scientific literature where measurement science, technique,

precision and accuracy are paramount, but will provide the data and

references for the necessary assessment by the user. The publication of both graphical and tabular data will be in a dual

system of physical units. These units will be the traditional LNG

industry British System of BTU , pound, degree Fahrenheit and the SI

system of joule, kilogram and kelvin. It is the intent to give equal

weight to each system of units.

7. Program and Results . The first edition of the User's Manual became

available for distribution in September 1977. A complete description

and ordering information are included as part of this report. Over 750

copies have now been distributed to sponsors and purchasers. New orders

are currently coming in at the rate of about ten per week. The first

supplement to the User's Manual is printed and 350 copies have been

d istr ibuted

On January 24, 1979 the LNG Materials and Fluids User's Manual received

the Award of Distinction (first place) of the Society for Technical

Communications. This award was in the category "Industrial Handbooks

and Manuals" and we believe recognized the efforts and contributions of

the sponsors and individual contributors.

Due to an initial uncertainty about the demand for the User's Manual

only 750 of the cover and dividers were ordered, however 1000 copies of

all graphs and text were printed. Our original stock of 750 was exhausted in April, therefore 250 additional covers and divider sets were ordered and are on hand for filling orders.

The second supplement is nearing completion. After some difficulty with

extremely high bids, a reliable printer was engaged. The second

supplement will contain approximately 20-25 graphs on composites, 6-10 on concrete, 15 updated graphs on structural materials, 15 graphs and 3 wall charts on propane properties and three graphs on mixture

properties

.

8. Problem Areas. None.

33
9. Level of Effort . January 1 - June 30, 1979

1.3

22. 3K$

9 5 . 0K$

Staff-years expended

Equipment and/or Services Purchased

Approximate expenditures, total

10. Future Plans . Work on the second supplement is in progress. Two groups

of originals will go to the printer in July and the last group in

mid-September. We hope to have the printed copies back in late November

for distribution.

34
1. Title . 01 ML JOINT SECRETARIAT ON LNG MEASUREMENTS

Principal Investigators . Douglas B. Mann and James A. Brennan, NBS and

T. L. Hillburn, Phillips Petroleum Company.

2 . Cost Center Number . 7360290

3. Sponsor Project Identification . American Gas Association, Inc.,

NBS-Office of International Standards; and NBS.

4. Introduction . The liquefied natural gas program of the National Bureau

of Standards Cryogenics Division has, over the past seven years,

provided the gas industry and interested Government agencies with

properties data on materials and fluids, instrumentation, and

measurement assistance in supplementary fossil energy supply. Support

of this program by the American Gas Association, Inc. , and Federal

Government agencies such as the Maritime Administration (MarAd), NASA,

GSA, Federal Power Commission and the NBS-Office of Standard Reference

Data has provided a basis for the national acceptance of the results of

the NBS LNG program. Through the U.S. membership in the International

Organization of Legal Metrology there exists, at the present time, an opportunity to extend, internationally, the utility of data and

measurement practice developed under our joint Government/industry

program. We have been requested (by OIML membership) to establish a LNG

Measurement Secretariat within OIML which, if implemented, would provide

a significant international forum for the results of our joint work. It

is believed that a joint Secretariat with the LNG industry would provide

the most effective means of accomplishing these objectives.

5. Objectives or Goals . Our objective is to accomplish the following goals.

a) To establish U.S. (NBS) thermophysical properties data for LNG as the standard data in international usage.

b) To establish U.S. (NBS) materials property data used in fabrication

and construction of LNG facilities (liquefiers, storage, transport) as the standard data in international usage.

c) To establish U.S. (NBS) approved measurement technology and

instrumentation as related to LNG (pressure, temperature, density,

liquid level, flow) as the standard in international LNG trade. The

precedent has been established with the successful completion of the

joint NBS-CGA cryogenic flow measurement program which has resulted in

the adoption of a cryogenic flow measurement code by the National

Conference on Weights and Measures. We wish to extend this code on an international basis.

d) To establish and maintain the leadership of U.S. science,

engineering, and industry in the research, technology, manufacture and

marketing of instruments and measurement systems for liquefied natural

gas

.

6. Background . OIML was founded in 1955 to promote intergovernmental

cooperation in the field of legal metrology which relates to the

compatibility of standards of measurement and the legislation and

government regulations which may affect such standards of measurement.

OIML recommends uniform international requirements for scientific and

measurement instruments used in industry and commerce and works out

model laws and regulations for consideration by member nations; and, in

35
addition, serves as a center of documentation and information exchange

in legal metrology. At present, 43 nations are members of this

intergovernmental organization.

The United States joined OIML in 1972 (the Senate by resolution of

August 11, 1972, gave its advice and consent to the accession of the

U.S. to the convention establishing OIML). The responsibility for

managing U.S. participation in OIML was assigned to the Department of

Commerce and has since been delegated by the Department to the National

Bureau of Standards (NBS). Under the general guidance of the Department

of State and the Secretary of Commerce, NBS is directly responsible for

formulating and implementing U.S. policy towards OIML. U.S. participation in the organization is deemed important for two reasons: First,

to protect and enhance some $1 billion worth of scientific and measurement instruments exported each year by U.S. firms and to ensure equity

in the trade of commodities measured by these instruments; and second,

to maintain the U.S. as the world leader in the field of metrology.

In the spring of 1975 at a meeting in Paris of the International

Committee of Legal Metrology, the French and U.S. representatives

discussed the possibility of creating a new Reporting Secretariat No. 15 on "Liquefied Natural Gas ( LNG ) Measurement." The U.S. representative,

W. E. Andrus, Jr. of NBS, agreed to explore the possibility with U.S.

industry and interested government agencies. These discussions resulted

in a decision to propose a joint Secretariat with the American Gas

Association and NBS-Cryogenics Division in order to best accomplish the

tasks. These conclusions were reached during several meetings extending

through the latter part of 1975 and early 1976. During the summer of

1977, representatives of NBS met with PTB (West Germany) and SIM

(France) to discuss the proposed scope and to explore expansion of the

effort to include cryogenic fluids in general. Results of those

discussions indicate some resistance to including different physical

measurements (flow, density, etc.) under a single recommendation for a specific group of fluids.

The proposed plan and scope were presented at the meeting of The

Advisory Committee for International Legal Metrology held at NBS-Boulder

in September. The committee encouraged NBS to proceed with the present

scope and to continue to explore the possible inclusion of other

cryogenic fluids.

A revised work plan for cryogenic fluids was generated by the technical

associates Douglas B. Mann of NBS and T. L. Hillburn of the Phillips

Petroleum Co. representing A.G.A. and API. The scope of the work plan

included instrumentation and procedures for the custody transfer

measurements of pressure, temperature, density, liquid level, flow and

calorific value of liquefied atmospheric and natural (hydrocarbon) gases

having pure fluid or mixture normal boiling points of less than 150 K. Recommendations will be limited to establishing total mass and, where

applicable, total heating value. Fluids and fluid mixtures considered

will be limited to commercially important liquefied atmospheric gases,

atmospheric gases, oxygen, nitrogen and argon and the primary components

of liquefied natural gas, methane, ethane, propane, iso- and normal

butane and pentane.

Flow measurements of pure cyrogenic fluids will be the first of the

recommendations generated under the proposed work plan. This will be

iccomplished by combining the existing U.S. and European codes for flow

measurements. A working group has been formed of interested parties and

36
the first draft of this recommendation should be ready for review by

January of 1980.

7. Program and Results . The two documents to be combined are: "Cryogenic Liquid Measuring Devices," NBS Handbook 44, 4th Ed. (with

supplements). National Bureau of Standards, Washington D.C. (1976)

"Code of Practice - Metering of Cryogenic Liquids," IGC Industrial Gases

Committee, 32, Boulevard de la Chapelle, 75880 Paris Cedex 18, France

(October 1976)

Funding delays have shifted the program to the latter half of 1979.

Initial outlines of the two codes have been completed, but detailed

synthesis have not begun.

8. Problem Areas . Funding delay has extended schedule, but does not cause additional problems.

9 . Level of Effort . Staff-years expended 0.06

Equipment and/or Services purchased 0.00

Approximate Expenditures $5,000

0. Future Plans . A first draft recommendat ion will be prepared by NBS as a simple combination of the two existing codes. This draft will be

distributed to the four members of the working group for review. The

revised first draft will then be submitted to the NBS-OIML representatives for OIML distribution.

37
Title. LNG SAFETY

Principal Investigators . Thomas R. Strobridge

Cost Center Number. 7360450

Sponsor Project Identification. Lawrence Livermore Laboratory (LLL)

order No. EY-78-X-03-029 (3/3/78)

Introduction . Small experimental spills of LNG have been conducted on both land and water. A number of mathematical models have been devised

describing pool size, spread rate, evaporation rate and plume dispersion

encorporating various descriptions of the surface on which the spill occurs and various atmospheric conditions. Lawrence Livermore

Laboratory has a program funded by DOE to conduct large spill tests on both land and water complimented by the appropriate instrumentation to

refine the measured characteristics of spills and the resulting plume,

thus providing improved and expanded data for further modeling efforts.

Recently, the LLL program was expanded to possibly include LPG, propane,

butane anhydrous ammonia and hydrogen.

Objectives and Goals . The objective of this project is to provide

consultation to LLL on an as-needed basis regarding safety, equipment

and engineering for low temperature applications.

Background . NBS has been active in safety programs for the combustible

cryogenic fluids for over 30 years. Most recently the major effort has

been on LNG safety.

Program and Results,

test site. LLL has

that have been used

We have recommended

testing, converting

LNG storage vessels will be needed at the spill

possession of two 28,000 gallon liquid oxygen dewars

for liquid nitrogen and are currently mothballed,

the procedures and requirements for inspecting,

and recertifying the dewars for LNG service.

An extensive literature search of ten data bases was conducted in

anticipation of experiments on LPG, propane, butane and anhydrous

ammonia spills. Those references suggested for the LLL spill library

were selected to give:

1 . design,

2 .

3.

4. and

5.

Thermodynamic and transport properties necessary for process

instrument selection and data analysis,

Materials compatibility for component selection.

References to applicable codes and standards.

Fundamental studies of combustion, plume dispersion and spills.

General safety and accident reports.

There are no plans at the present time to combine the results of the

various literature searches in a form for public release.

Problem Areas . None

L evel of Effort . January 1 - June 30, 1979

Scaff years expended 0.1

Equipment and/or Services Purchased -0-

Approximate Expenditures, Total $7,500.00

Future Plans . Provide consulting services as needed.
114A (REV. 9-7«)

U.S. DEPT. OF COMM. IBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. 3. R«clp*ent’ $ Accession No.

friTLE AND SUBTITLE

LIQUEFIED NATURAL GAS RESEARCH AT THE

NATIONAL BUREAU OF STANDARDS

5. Publication Date September 1979

Performing Organization Code

! AUTHOR(S) 8. Performing Organ. Report No.

PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

| WASHINGTON, DC 20234

18. Project/Task/Wortr Unit No*

11. Contract/Grant No.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, state. ZIP)

See page ii

13. Type of Report & Period Covered

1 Jan 1979-30 June 1979

. y,- .

. SUPPLEMENTARY NOTES

i Document describes a computer program; SF-185, FIPS Software Summary, is attached.

literature survey, mention it here.) The objective of this report is to:

1. provide all sponsoring agencies with a semiannual report on the activities

of their individual programs

2 .

3.

inform all sponsoring agencies on related research being conducted at the

NBS-NEL Thermophysical Properties Division, NBS-NEL Mechanical Processes

Division and NBS-NML Fracture and Deformation Division;

provide a uniform reporting procedure which should maintain and improve

communication while minimizing the time, effort and paperwork at the cost

center level.

The work is supported by NBS and seven other agencies and represents the

Jollective expenditure of $619,000 during the 6-month reporting period. The contents

'f this report augment quarterly progress meetings for certain of our sponsors and

provide a perspective which is missing when the parts are viewed individually,

distribution of this document is limited and intended primarily for the supporting

J.gencies. Data or other information must be considered preliminary, subject to change

j ind unpublished, and therefore not for citation in the open literature .

• KEY WORDS (six to twelve entries ; alphabetical order; capitalize only the first letter of the first key word unless a proper name;

separated by semicolons)

ryogenics, liquefied natural gas; measurement; methane; properties; research

8. AVAILABILITY Unlimited

for Official Distribution. Do Not Release to NTIS

Order From Sup. of Doc., U.S. Government Printing Office, Washington, DC

20402, SD Stock No. SN003-003-

Order From National Technical Information Service (NTIS), Springfield, VA. 22161 _

19. SECURITY CLASS 21. NO. OF

(THIS REPORT) PRINTED PAGES

UNCLASSIFIED

20. SECURITY CLASS 22. Price (THIS PAGE)

UNCLASSIFIED USCOMM-DC
'