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NBSIR 77 - 864

DO NOT REMOVE

LIQUEFIED NATURAL GAS RESEARCH

at the

NATIONAL BUREAU OF STANDARDS

PROGRESS REPORT FOR THE PERIOD - OTP

1 JANUARY - 30 JUNE 1977

D.E. Oilier, Editor

CRYOGENICS DIVISION • NBS-INSTITUTE FOR BASIC STANDARDS • BOULDER, COLORADO

NBSIR 77 - 864

LIQUEFIED NATURAL GAS RESEARCH

at the

NATIONAL BUREAU OF STANDARDS

D.E. Diller, Editor

Cryogenics Division

Institute for Basic Standards

Notional Bureau of Standards

Boulder, Colorado 80302

Progress Report for the Period

1 January - 30 June 1977

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

Sidney Harman, Under Secretary

Jordan J. Baructi, Assistant Secretary for Science and Tectinology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Acting 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.)

Federal Power Commission

Bureau of Natural Gas

Washington, DC 20426

U. S. Department of Commerce

Maritime Administration

Washington, DC 20235

U. S. Department of Commerce

National Bureau of Standards

Institute for Basic Standards

Boulder, Colorado 80302

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 Sampling Measurements Supervisory Committee

National Aeronautics and Space Administration

Lewis Research Center

Cleveland, Ohio 44135

American Bureau of Shipping

45 Broad Street

New York, NY 10004

ii
ABSTRACT

Twenty-six cost centers, supported bv six other aqency sponsors in

addition to NBS, provide the basis for liquefied natural gas (LNG) research

at NBS. During this six-month reporting period the level of effort was over

20 man-years/year with funding expenditures of over $500,000. This

integrated progress report, to be issued in January and July, is designed to:

1) provide all sponsoring agencies with a semi-annual and an annual

report on the activities of their individual programs ;

2) inform all sponsoring agencies on related research being con- ducted at the Cryogenics 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 contents of this report will augment the quarterly progress meetings of some sponsors, but will not necessarily replace such meetings.

Distribution of this docum.ent is limited and intended primarily for the

supporting agencies. Data or other information must be considered pre - liminary, 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

REFERENCE DATA

Cost Center Page

a) THERMOPHYSICAL PROPERTIES DATA FOR PURE

COMPONENTS AND MIXTURES OF LNG COMPONENTS (American Gas Association,

Inc.; NASA Lewis Research Center)

2750574 and

2750548

b) FLUID TRANSPORT PROPERTIES

(NBS-Office of Standard Reference Data)

c) PROPERTIES OF CRYOGENIC FLUIDS (NBS)

d) PROPERTIES OF CRYOGENIC FLUID MIXTURES

(NBS: NBS-Office of Standard Reference

Data; AGA)

2750124

2750141

2750142,

2750145 and

2754574

8

11

DENSITIES OF LIQUEFIED NATURAL GAS

MIXTURES (LNG Density Project Steering

Committee - AGA)

2751574 14

f) PROGRAM FOR REDUCING THE COST OF LNG SHIP 2751430,

HULL CONSTRUCTION — PHASE II SHIP STEEL 2752430 and

IMPROVEMENT PROGRAM (Maritime Administra- 2753430

tion

)

17

II, MEASUREMENT SCIENCE

CUSTODY TRANSFER - LNG SHIPS

(Maritime Administration)

2750460 19

HEATING VALUE OF FLOWING LNG (Pipeline

Research Committee - AGA)

2756579 22

LNG DENSITY REFERENCE SYSTEM

(American Gas Association, Inc.;

National Bureau of Standards)

2757574 and 24

2750161

d) LNG SAMPLING MEASUREMENT STUDY (LNG

Sampling Measurements Supervisory

Committee

)

2750575 25

III. TECHNOLOGY TRANSFER

SURVEY OF CURRENT LITERATURE ON LNG

AND METHANE (American Gas Association,

Inc. ) 2759574

27

b) LIQUEFIED NATURAL GAS TECHNOLOGY TRANSFER

(Maritime Administration; American Gas

Association, Inc.; American Bureau of

Shipping; NBS-Office of Standard Ref- erence Data)

OIML JOINT SECRETARIAT ON LNG MEASUREMENTS (American Gas Association, Inc.;

NBS-Office of International Standards;

NBS-Cryogenics Division)

2750403

,

2751403,

2752403,

2750570,

2754574,

2758574 and

2750127

2750104

29

31

d) FEDERAL POWER COMMISSION CONSULTATION

- , iv

2750404 33
] , Title. THERMOPHYSICAL PROPERTIES DATA FOR PURE COMPONENTS AND

niXTURES OF LNG COMPONENTS

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

R. Tsumura*, W. M. Haynes , and R. D. McCarty

2. Cost Center Number . 2750574, 2750548

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

Project BR-50-10. National Aeronautics and Space Administration,

Lewis Research Center, Purchase Order C-78014-C.

4. 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 as well as 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 thermophy sical 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

.

5. 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 9 0 K and

300 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.

6. 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 mixtures 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

Consejo Nacional de Ciencia y Tecnologia (CONACYT) Mexico City. Currently

a guest worker with the Cryogenics Division, National Bureau of Standards,

Institute for Basic Standards in Boulder, Colorado.
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 composition, temperatures and pressure. 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 industry 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 accurate basis for calculating

thermophysical properties data for LNG and hydrocarbon mixtures.

7 . Program and Results .

7.1 Ethane, Specific Heat Data - - H . M. Roder

This phase of the program is complete. Two manuscripts describing

the results of the research have been published:

H. M. Roder, Measurements of the Specific Keats, Co and Cv, of Dense

Gaseous and Liquid Ethane, J. Res. Nat. Bur. Stand. (U.S.), Vol 80A,

No. 5, 739-59 (Sep-Oct 1976).

H. M. Roder, The Keats of Transition of Solid Ethane, J. Chem. Phys.

Vol 65, No. 4, 1371-3 (Aug 1976).

7.2 Ethane , Sound Velocity Data -- _R ^_T

s

umura, G. C. Straty

This phase of the program is complete. The results of the research

have been reported in the following publication:

R. Tsumura, G. C. Straty, Speed of Sound in Saturated and Compressed

Fluid Ethane, Cryogenics Vol 17, No. 4, 195-200 (Apr 1977).

7.3 Ethane, Thermophysical Properties Data -- R. D. Goodwin

The manuscript, National Bureau of Standards Technical Note 684,

"Thermophysical Properties of Ethane, From 90 to 600 K at Pressures to

700 Bar," by R. D. Goodwin, H. M. Roder, and G. C. Straty (August 1976)

has been published and distributed.

7.4 Propane, Thermophysical Properties Data — R. D. Goodwin

Available, published physical properties data, acquired through our Cryogenic Data Center, have been evaluated and formulated as required

for thermodynamic computations. These numerous properties now have

been used to compute a complete set of provisional tables of

thermodynamic functions.

The manuscript, "Provisional Thermodynamic Functions of Propane, From

85 to 700 K at Pressures to 700 Bar," is complete and has been released

by the NBS Editorial Review Board. This will be published as National

Bureau of Standards Internal Report, NBSIR 77-860, within six weeks.

Work will commence in one to two months on measuring and analyzing

specific heat data for liquefied and gaseous propane.

2
7.5 Propane, Experimental Measurements — W. M. Haynes

A new apparatus has been developed for pressure, temperature, density,

composition, and dielectric constant measurements on liquids and liquid

mixtures at temperatures between 7 0 and 350 K and at pressures to

35 MPa (approximately 5000 psi) . This apparatus, which incorporates a magnetic suspension technique in the density determination, is significantly different and more versatile than the instrument previously

used in the LNG Density Project.

The overall dimensions of the new copper cell are roughly the same as the cell used previously, except for an increase in the thickness of

the walls required for use at higher pressures. The internal free

volume is approximately 40 cm^ , or twice that of the previous cell.

This increase in the internal free volume of the cell is due largely to

the complexity in the assembly of the capacitor and magnetic sensor,

their supports, and seven coaxial leads. As long as enough mixture can

be prepared to fill the cell (which is the case for all mixtures being

considered here) the additional free volume presents several advantages;

e.g., the liquid-to-gas volume ratio is larger.

A new window assembly, which can be used to pressures of 5,000 psi or larger, has been tested. The assembly consists of a sapphire disk

(3/4" diameter x 1/4" thick), indiiim gasket, asbestos rubber backing

material and stainless steel plug and ring with four 1/4-20 stainless

steel set screws to provide a pressure- and vacuum-tight seal. It has

a 1/4 inch diameter viewing area and is naturally located at the height

at which the magnetic float is suspended. With this apparatus the

liquid-vapor interface cannot be observed visually. This is not

necessary in determining when the cell is full of liquid. This can be

accomplished by monitoring the pressure and temperature of the cell and

its contents. The complexity of the apparatus and the high pressure

consideration made impractical a visual observation of the liquid-vapor

interface

.

The new cell will have an additional capillary into the top of the cell,

which is primarily for (vapor) pressure measurements in a capillary that

is independent of the recirculation lines. The recirculation heat

exchanger length and volume have been reduced considerably since the

previous measurements exhibited that there was little heat load on cell

during recirculation. It is now possible to fill the cell from either

the top or bottom, or both simultaneously.

A platinum resistance thermometer is again the primary temperature

sensor and is located at approximately the same vertical position as the magnetic float. It is attached with indium in a container softsoldered to the cell. Due to the high pressures, it was not practical

to install a vapor bulb inside the cell. However, two vapor bulbs

(each with an internal volume of 2 cm^) have been installed at the ends

of the cell in close thermal contact (soft-solder) with the outside

surface of the cell. These will be used to monitor temperature gradients

along the length of the cell. Differential thermocouples (chromelconstantan) have been located at the same positions as the vapor bulbs

and the voltage output from these will be used to null temperature

differences along the length of the cell.

An existing cryostat, which could be used to lower temperatures than

that of the previous work, has been extensively modified to be compatible

with the magnetic suspension densimeter. Cooling- is accomplished by

reflux action or exchange gas (along with conduction down leads and

capillaries) through a central tube that passes through the liquid

nitrogen reservoir and is attached to the cell lid. (Means have also

been provided, if needed, for cooling at the bottom of the cell through

tubes connected to a copper ring soft-soldered to the cylindrical surface

of the cell near its bottom. ) Above the cell on the central tube (thinwalled stainless steel) a guard ring is used to thermally temper the

3
electrical wires that are wound on the cell. The temperature of the

guard ring is controlled at the same temperature as the cell through the use of a chromel-constantan differential thermocouple between the guard

ring and cell and the use of a vapor bulb placed in good thermal contact

with the guard ring. For temperature control, a 100 Q heater has been

wound on the guard ring and four independent 125-160 Q. heaters on the

cell along its length.

The pressure measurements will be accomplished using the same procedures

as employed in the earlier work. An oil dead-weight gauge has been

connected to determine the pressure of the fluid inside the cell,

especially at pressures larger than 2 atm. or 30 psi. At low pressures,

the calibrated spiral quartz Bourdon gauges will be used as before.

A differential capacitance sensor is being used to detect the motion of

the magnetic float; previously a linear differential transformer (LDT) was utilized for this purpose. A differential capacitance sensor is

being used to alleviate the problems of pressurized fluid penetrating

the windings of the inductance coils and of changes in the position of

the float due to changes in the dielectric constant of the test fluid.

The new sensor has approximately the same sensitivity as the LDT and

has been used to support the float without problems. Final adjustments

and tests have not been carried out to eliminate the dependence of the

float height on the dielectric constant of the fluid. These adjustments

will not be carried out until the apparatus is completely assembled

since all adjustments are made to electric components outside the

cryostat. The servosystem used in the previous work was modified to be

compatible with the new sensor. With the new cryostat there is no mechanical mechanism to change the position of the float. All changes

in the float position, if needed due to thermal expansion effects in

cryostat, cell, supports, etc., will be accomplished electronically with

coarse and fine capacitors located at the top of the cryostat. With

these capacitors it is easy to change and fix the float's height within

the desired precision, approximately 10"-^ mm. The same 125X microscope

as used in the previous work, except for different lenses, will be used

as the primary means for determining the position of the float.

A new main coil (of larger diameter to be compatible with new cell) has

been wound from epoxy-coated aluminum foil. The maincoil consists of

two coils epoxied to a central quartz tube. The quartz tube is supported

on a fiberglass plate that is supported by (three) one-inch diameter

quartz rods. Water-cooled copper plates have been placed in good

thermal contact with all faces of the two coils. No problems have been

encountered with this arrangement for mounting and cooling the coils at

currents to 1.5 A. (270 watts). (The outside diameter of the new main

coil was made less than the inside diameter of the gradient coils used

in the previous work in case a need for a three coil system cropped up

again.) A new calibrated 0.5 Q. standard resistor, which can withstand

currents of 2 A without degradation of its specifications, has been

obtained and placed in an insulated oil bath. This resistor is in

series with the main coil and the measurement of the voltage drop across

this resistor enters directly into the calculation of density.

A capacitor with slotted concentric cylinders has been placed just above

the density sensor. It will be used for simultaneous dielectric constant

measurements on the fluids for which PVTx data are obtained. The

capacitor is made from copper and has a capacitance of approximately 20

pF in air at room temperature. It has been tested in air and in liquid

hexane at room temperature. It appears to be mechanically stable and

its overall stability is such that the capacitance can be determined

routinely to 0.0001 pF

.

The entire apparatus is in the final stages of assembly. Barring

unforeseen difficulties, it should be completely assembled within the

next week or so. Performance tests will follow and hopefully be

4
completed the first part of August. The float that has been wellcharacterized from the previous work will be used again.

The cell and window assembly have been tested to pressures above 6,000

psig at room temperature and at 76 K using helium gas. The cell has

been cycled between these temperature extremes five times. No leaks were encountered.

The "guts" of the apparatus (the capacitor, differential capacitance

sensor, and associated parts) survived the severe test of a sudden

immersion in liquid nitrogen and subsequent rapid warmup to room

temperature. The cryostat has been leak checked while the reservoir

was full of liquid nitrogen. The systems for handling (charging cell,

sampling, recirculation, pressure measurements and control, vacuum, vent,

etc.) of the fluids under study have been assembled and leak checked.

7.6 Calculational Methods — R. D . Mc Carty

Of the four calculational methods evaluated and optimized under another

cost center (2751574), the present investigation has shown the extended

corresponding states method to be the most promising method for predicting

the thermophysical properties of mixtures over a wide range of temperature

and pressure. The rigorous mapping of a model for the equation of state

of methane to a model for the equation of state for nitrogen has been

accomplished via the extended corresponding states theory. Determination

of the binary interaction parameters using PVTx and phase equilibria

data simultaneously, together with non-linear least squares parameter

estimation techniques, is now in progress.

8. Problem Areas. None.

9. Funding. January 1 - June 30, 1977.

Man-years expended

Equipment and/or Services Purchased

Total Reporting Period Cost

Balance Remaining

10. Future Plans . Objectives and Schedule: Quarter 3 4 Analyze and report available

physical properties data for >

propane

.

Prepare and performance test PVT

and dielectric constant

properties apparatus for propane.

Evaluate and optimize promising

calculation methods for the

thermodynamic properties of

methane-nitrogen mixtures.

Measure, analyze and report specific

heat data for propane.

1.1

11. 8K$

81. 2K$

72. 3K$

5
Title

,

FLUID TRANSPORT PROPERTIES

P rincipal Investigator . Howard J. M. Hanley

Cost Center Number . 2750124

Sponsor Project Identification . NBS-Office of Standard Reference Data

Introduction . Methods for predicting tne 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 mea- surements relating to transport properties, specifically the viscosity

and r.hermal conductivity coefficients, of simple mixtures over a wide

rarge 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 Pnd applied to produce practical

numerical tables of the viscosity, thermal conductivity and diffusion

{ 3

)

coefficients of simple fluids: Ar , Kr , Ze , N_, 0^, F„, He, H^ , CH .

,

Recent work has extended this approach to propane. It has been shown

that a successful mixture program can emerge from combining the results

for pure fluids with equation of state studies. The equation of state

work is being carried out by other investigators in this laboratory.

Program and Results . A procedure to predict the transport properties of

mixtures has been developed via corresponding states . ^-'-"^ ^ The method

has been shown to be satisfactory. Current studies include investigating the effects of internal degrees of freedom on the thermal

conductivity coefficient and the behavior of the transport coefficients

near a critical point. The program has been expanded by the

addition of James C. Rainwater, a NBS/NRC Postdoctoral Research Fellow,

who is investigating the theoretical background.

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.

Funding . January 1 - June 30, 1977.

(4)

Allocation

Labor

Other Costs

60. OK$/yr,

0. 5 MY 32 . 8K$

3.6K$

Total 36.4K$

Future Plans . The transport properties of ethylene will be investigated.

The corresponding states predictive procedure for mixtures will be

expanded in line with the concurrent equation of state studies.
References

1. E, 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.

2. H. J. M. Hanley, Transport Coefficients in the One-Fluid Approximation:

Behavior in the Critical Region, Mol. Phys . (1977).

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, (1977).

7
Title . PROPERTIES OF CRYOGENIC FLUIDS

Principal Investigators . G, C. Straty, H. M. Roder, L. A. Weber, B. J. Ackerson, and D. E. Diller

Cost Center Number . 2750141

Sponsor Project Identification . NBS

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.

Objectives or Goal s . 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. 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. Sound

velocity data are useful for testing the consistency of volumetric,

calorimetric and thermodynamic properties data, and are potentially

useful for density gauging applications. Thermal diffusivity data are required for performing thermodynamic and heat transfer calculations.

Background . When light is incident on a perfectly homogeneous fluid,

the reradiated (scattered) light field sums to zero in all but the exact

forward direction. For a "real" fluid, however, fluctuations, arising

through various mechanisms, destroy the perfect homogeneity and result

in the scattering of light in other directions as well. For example,

thermally activated density fluctuations (phonons) , propagating with

the characteristic velocity of sound, give rise to scattered light which

is Doppler shifted in frequency from the incident light frequency and

whose spectrum contains information on the sound velocity and attenuation. Local non-propagating temperature fluctuations, which decay

diffusively, give rise to scattered light in a narrow frequency band

about the incident light frequency and whose spectrum contains

information on the lifetime of the fluctuations (thermal diffusivity)

.

Since the frequency shifts are generally very small, it was not until

the advent of the lasers with their extremely well defined frequency,

that practical experiments using these phenomena were possible.

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 f usivities 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.

8
7. Program and Results . 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

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

increasing to 10% or greater further away. A detailed analysis of the

data and experimental error is presently being made and a paper reporting

the results is in preparation.

8. 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.

We have investigated other experimental techniques for obtaining widerange thermal conductivity measurements on compressed and liquefied

gases and have decided that the transient hot-wire method offers the

clearest advantages. Initial design steps have been taken including

exploring the automation and electronics techniques that will be

required for data acquisition and reduction. Several pieces of

equipment have been ordered.

9
9. Funding . January 1 - June 30, 197 7 Man-years expended

Equipment and/or Services Purchased

Total Reporting Period Cost

Balance Remaining

3.1K$

39.6K$

40. 3K$

0. 5

10. Future Plans.

Objectives and Schedule: Quarter 3 Measure, analyze and report

thermal diffusivity

coefficient data for

methane in the critical region.

Design, construct and performance

test transient hot-wire thermal

conductivity apparatus.

10
Title . PROPERTIES OF CRYOGENIC FLUID MIXTURES

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

W. C. Miller (part-time) . Cost Center Numbers . 2750142, 2750145 and 2754574

Sponsor Project Identification . NBS , NBS (OSRD) , AGA

Introduction . Accurate thermodynamic properties data and predictive

calculation 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

predictive calculation methods.

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

provide critically evaluated data, original and from other sources, 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.

Background . A physical equilibria of mixtures research project was established in the Cryogenics 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 problem.s.

Recent efforts have been directed toward problems associated with

systems containing components with overlapping liquid temperature

ranges, such as the nitrogen + methane system.

11
Program and Results . The recent progress is summarized as follows:

a) A paper reporting new liquid-vapor equilibria measurements for

the methane + ethane and the methane + ethylene systems has been

published in the Journal of Chemical Thermodynamics 9^, 167-78

(1977) . b) Data on the liquid-vapor equilibria, Henry's constants, excess Gibbs functions, liquid phase heats of mixing and excess volumes

have been compiled, evaluated, and correlated for the methane + ethane system. A paper discussing this work is now in editorial

review. This paper will be published in the Journal of Physical

and Chemical Reference Data.

c) An equation of state, recently proposed by Peng and Robinson, has

been optimized to represent the phase equilibria data for the

nitrogen + methane and methane + ethane systems. The optimized

equation has now been used to generate the nitrogen + methane

K-values and liquid and vapor equilibrium compositions for

inclusion in the LNG Materials and Fluids user's manual. Work is now in progress to generate methane + ethane K-values and liquid

and vapor equilibrium compositions for future inclusion in this

manual. In addition, graphs of orthobaric liquid densities of

methane and of nitrogen + methane mixtures (up to 5 mole percent

nitrogen) were prepared from experimental data obtained in the LNG

density project for inclusion in the LNG Materials and Fluids user'

manual.

d) An empirical excess volume model has been developed based on orthobaric liquid density measurements for the pure components

and binary mixtures completed in the LNG density project. This

model has been tested on multicomponent LNG mixtures data and

appears to be a simple and reliable method for predicting LNG

densities from 105 to 120 K. A paper discussing the development

of this model is in editorial review and will be submitted to the

Journal of Fluid Phase Equilibria.

e) Molar volume measurements were made at the University of Wyoming

on one methane + ethane binary mixture and on four multicomponent

mixtures containing either isobutane or normal butane, with and

without nitrogen present. These measurements supplement the

measurements made in the magnetic suspension densimeter and add

evidence to substantiate the ability of correlation models to

predict orthobaric densities of LNG. These results are now being

compared with predicted results from the optimized excess volume

model, and a paper is being prepared for the Journal of Fluid

Phase Equilibria.

Problem Areas. None.

Funding . January 1 - June 30, 1977.

Man-years expended 0.8

Equipment and/or Services Purchased 4 . 8K$

Total Reporting Period Cost 64.3K$

Balance Remaining 43.5K$

12
Future Plans.

Objectives and Schedule: Quarter

Evaluate, correlate and report

liquid-vapor equilibrium

properties data for methane + ethane mixtures.

Prepare and report graphs of

liquid-vapor equilibrium

properties data for nitrogen + methane mixtures.

Analyze and report total vapor

pressure data and orthobaric

liquid densities for methane + ethane mixtures.

Prepare and report graphs of

liquid-vapor equilibrium

properties data for methane + ethane

.

Design, construct and performance

test phase equilibria apparatus

for total vapor pressure

measurements on methane + isobutane mixtures.

Evaluate and report molar volume

data on multicomponent mixtures

of LNG components obtained at

the University of Wyoming.

13
Title . DENSITIES OF LIQUEFIED NATURAL GAS MIXTURES

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

W. R. Parrish

Cost Center Numbers . 2751574

Sponsor Project Identification . LNG Density Project Steering

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

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.

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.

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 0.1%.

Program and Results . 7.1 Measurements . All measurements on pure fluids, as well as binary

mixtures have been completed and reported .

^ ^ ' ^ / 3 , 4 ) inconsistencies

found in the butane-containing multicomponent mixtures (without nitrogen) were mentioned in the last report. These have been identified as probably arising from inadequate mixing within the cell. Previous

data, published and unpublished, from the University of Wyoming and

Elf Aquitane in France tend to support this supposition. This

hypothesis was further supported by additional measurements performed

on the Wyoming apparatus by a member of the NBS staff. (See report of

Project 2750142 for more details.) The LNG Density Project Steering

Committee has agreed to fund additional measurements to fully resolve

the inconsistencies. The report on the previous NBS multicomponent

mixtures data will therefore be delayed. The magnetic densimeter has

been extensively modified to allow measurements to higher pressures.

This work and the new apparatus is fully described in the report for

cost center number 2750574.

14
A two part paper (experimental and calculational ) will be presented at

the Fifth International Conference on Liquefied Natural Gas in

Diisseldorf, Germany in August 1977.

7.2 Calculational Methods . Four promising methods of calculating the

densities of liquid mixtures have been tested, modified and optimized

utilizing the pure component and binary mixture data reported above.

The four methods are a corresponding states method, a cell model, a hard-sphere model and an excess volume model. Computer programs have

been written for all four methods and these have been used to calculate

densities for comparison with the data for the mixtures measured. The

calculated results agree with the experimental data to within 0.1% for

all multicomponent mixtures except those containing methane and butanes

but no nitrogen. If nitrogen is present the differences reduce to

0.1% or less. Comparisons of the four methods with both published and

unpublished data from the University of Wyoming and Elf Aquitane in

France show deviations of less than + 0.15% between measured and

calculated densities. It is felt that only small corrections to the

four methods will likely need to be made as a result of the new

measurements proposed in 7.1 above.

Two of the four methods have been modified to account for the presence

of small amounts of the pentanes. The modifications were based on published data for pure, normal and iso-pentane.

The results of the calculational efforts will be presented to the Fifth

International Conference on Liquefied Natural Gas as mentioned in 7.1

above. A more complete accoun"c of the calculational methods study

(including the four computer programs) has been prepared, reviewed and

revised. This report will be published as an NBSIR in about two months.

8 . Problem Areas . None

.

9. Funding. January 1 - June 30, 1977.

Man-years expended 0.1

Equipment and/or Services Purchased

(Includes printing costs and travel

expenses for LNG-5 Conference) 4 . 6K$

Total Reporting Period Cost 4 . 6K$

Balance Remaining 0 . 3K$

10 . Future Plans . Objectives and Schedule: Quarter 3

Prepare and distribute calculational

methods report. >

Performance test new magnetic

densimeter PVT apparatus. >

Measure, analyze, and report

multicomponent mixture data,

including selected LNG-like

mixtures

.

References

1. W. M. Haynes and M. J. Hiza, Orthobaric Liquid Densities of Normal

Butane from 135 to 300 K as Determined with a Magnetic Suspension

Densimeter, Advan. Cryog. Eng. Vol 21, 516-21 (Plenum Press, New York,

1976) .

15
2. W. M. Haynes and M. J. Hiza, Measurements of the Orthobaric Liquid

Densities of Methane, Ethane, Propane, Isobutane, and Normal Butane,

J. Chem. Thermodynamics Vol 9, 179-87 (Feb 1977).

3. M. J. Hiza, W. M. Haynes and W. R. Parrish, Orthobaric Liquid Densities

and Excess Volumes for Binary Mixtures of Low Molecular Weight Alkanes

and Nitrogen Between 105 and 140 K, J. Chem, Thermodynamics Vol 9 (Sep 1977) . 4. W. M. Haynes, M. J. Hiza and N. V. Frederick, Magnetic Suspension

Densimeter for Measurements on Fluids of Cryogenic Interest, Rev. Sci.

Instrum. Vol 47, No. 10, 1237-50 (Oct 1976).

5. W. M. Haynes, A Simplified Magnetic Suspension Densimeter for Absolute

Density Measurements, Rev. Sci. Instrum. Vol 48, 39 (1977).

6. W. M. Haynes, M. J. Hiza, and R. D. McCarty, Densities of LNG for

Custody Transfer, Proc. Fifth International Conference on Liquefied

Natural Gas, Diisseldorf, Germany, Aug 29-Sep 1, 1977 (to be published).

7. D. E. Diller, LNG Density Determination, Hydrocarbon Proc. Vol 56, No. 4,

142-4 (Apr 1977)

.

16
1. Title . PROGRAM FOR REDUCING THE COST OF LNG SHIP HULL CONSTRUCTIOi^ -- PHASE II SHIP STEEL IMPROVEMENT PROGRAM

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

2. Cost Center Number . 2753430 - LNG Ship Hull Materials (Shipyard Contracts)

2751430 - LNG Ship Construction Materials (Metallurgical Evaluation)

2752430 - LNG Ship Hull Materials (Fracture Properties)

3. Sponsor Project Identification . Maritime Administration Misc. P. 0.

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 0 to -5 0°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

welding 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. Ob j ective . 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 raid-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 197 5 to the three

participating shipyards: Avondale Shipyards, Inc., Newport News Shipbuilding and Drydock Co. and General Dynamics-Quincy Shipbuilding Division.

A similar contract was signed with Lukens Steel Company to evaluate Cbtreated V-051 steel with and without sulfide shape control.

7. Program and Results . The shipyard evaluation phase of the Ship Steel

Improvement Program was completed by the three participating shipyards:

Avondale Shipyards Inc. (ASI) ; General Dynamics, Quincy Shipbuilding

Division (GDQ) ; and Newport News Shipbuilding (NNS) . Work is continuing

on a similar evaluation being conducted by the Lukens Steel Company on Cb-treated higher-strength-steel. The overall program, the results and

the conclusions are summarized in this section.

17
For the shipyard evaluation, the four major plate producers supplied the three participating LNG shipyards with production heats of

ABS steels modified to possess improved transverse toughness properties at low temperatures. The LNG shipyards evaluated plates from

these heats by qualifying optimum weld procedures in accordance with

the usee requirements. The specific steels evaluated by each shipyard and the test temperatures used in the weld procedure qualification testing are summarized below:

Shipyard Steel Producer Test Temperature Steel Grade

Avondale

Avondale

General

Dynamics

General

Dynamics

Newport News

Lukens

Lukens

Armco

Armco

U.S. Steel

Bethlehem Steel

Bethlehem Steel

Lukens

Lukens

-40°F

-60°F

-30°F

-60°F

-30 and -45°F

-40, -60, -75

-40, -60, -75

V-062 (S<.01%)

V-062 (SSC)

CS (SSC)

A537A (SSC)

V-051 (SSC)

V-051 (Cb, S<.04%)

V-051 (Cb, SSC)

Each shipyard evaluated 1/2 and 1-inch-thick plates from their heats of

steel by qualifying optimum welding procedures in accordance with USCG

requirements and by comparing these procedures with those currently used

for conventional ABS grades. The processes (and positions) evaluated were:

submerged arc (flat) , gas metal arc (flat and vertical) and shielded metal

arc (flat and vertical). The weld procedure qualification testing was limited to conducting the Charpy impact toughness traverse at the specified test temperatures. For these tests, specimens are cut transverse to

the weld axis (and the plate rolling direction) with the notches normal

to the plate surface.

The steels with sulfide shape control had excellent toughness at the test

temperatures, however, this improved toughness was not consistently

reflected in improved HAZ toughness. All of the ABS grades had satisfactory HAZ toughness when welded by the SMA or GMA processes. The SA

welds were satisfactory for heat inputs up to 100 KJI for CS at -30°F,

for V-061 for heat inputs up to 125 KJI at -60°F and for V-051 for heat

inputs to 85 KJI at -45°F. This represents an improvement over conventional steels for grades CS and V-062 and comparable results for V-051.

The ASTM grade A537A modified with sulfide shape control exhibited

improved base metal toughness but lower HAZ toughness than the conventional grade. This steel exhibited unsatisfactory results at low and

high heat inputs when tested at -60°F.

8 . Problem Areas . The metallurgical factors that contribute to the degradation of HAZ toughness have not been clearly delineated in the program

and it is unlikely that a satisfactory evaluation of these factors will

be completed during the remainder of the program.

9. Funding. January 1, 1977 to June 30, 1977.

Cost Center

2753430

2751430

2752430

Cost to 6/30/77

144 K$

64 K$

48 K$

Balance

1 K$

16 K$

12 K$

10. Future Plans . The Lukens Steel Co. evaluation of Cb-treated V-051 should

be completed by December 31, 1977. Work should start on the comparative

tasting program (Phase II of the Ship Steel Improvement Program) in the

fall of i977.

18
1. Title . CUSTODY TRANSFER - LNG SHIPS

Principal Investigators . R. S. Collier and J. D, Siegwarth

2. Cost Center Number . 2750460

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

#400-79005.

4. Introduction . In response to a request from the U.S. shipbuilding

industry, NBS is conducting an independent design review of the shipboard custody transfer systems under the sponsorship of the Maritime

Administration and in cooperation with the major U.S. shipbuilding

companies.

5. Ob j ectives . The objectives of this program are to 1) Identify the

major technical areas relating to uncertainties in the measurement of

total mass and total heating value, 2) Estimate uncertainties in the

total mass and total heating value due to these identified factors,

3) Develop a proposed testing program for custody transfer system components, and 4) Investigate improved gauging techniques.

6. Background . Previous funding provided for the initial design review

of ships designated by MA Design LG8-S-102a MA Hulls 289, 290, 291.

The current funding provides for an extension of this program to include

ships of other designs which are being built by the major U.S. shipbuilding companies and also to verify tank survey and gauging methods

for LNG custody transfer.

7. Program and Results . Working relationships with four major U. S. shipbuilders have been initiated. Most of the problem areas which

are common to custody transfer systems of all types have been identified

and are listed as follows:

1. Density

a) accuracy

b) rangeability

c) stability

2. Tank Strapping (Tank Surveys)

a) thermal effects

b) loading factors

c) measurement techniques

3. Convection (Non-Uniform Density)

a) density or composition stratification

b) possible isolation of measurement stillwells

4. Tank Weathering

a) time changes in composition, stratification, etc.

b) composition measurement

c) sampling

5. Liquid Level/Total Volume Measurement

6. Pressure and Temperature Measurements (gradients included)

.

7. Electronic Signal Conditioning, Data Reduction, Analysis and

Readout

One of the factors in shipboard evaluation of liquefied natural gas (LNG)

energy content and cargo value is to determine the volume of LNG in the

ships' tanks. This is done by measuring the liquid level together with

an independent determination of the ship tank capacity tables (volume

19
vs. height, with list and trim corrections). Shipbuilders, transporters,

buyers and sellers of LNG desire a total uncertainty in the ship tank

capacity tables of 0.1% or less. This means that the inside surfaces of

the tank must be. located to within something less than 1 cm for ship tanks

of major dimension on the order of 36 meters. The tank survey is obtained

under ambient conditions and corrections must be made for thermal con- traction as well as stresses due to cooling and loading. The tank survey

measures coordinate distances from target locations on the tank sur-face.

These measurements are normally taken using a measuring tape, a theodolite,

or a stereo-photogram. The tank surface is then obtained by modeling

(mathematically) a surface passing through the measured target locations.

The stereo-photogrammetric technique is relatively new for these applications,

but it is becoming accepted because of a number of attractive features: 1)

The measurements can be made accurately, consistently, 2) There is a permanent visual record of the tank targets and their locations, 3) Often,

targets other than the primary ones can be located (scratch marks, seams,

welds, etc.); These can aid, after the fact, if questions arise concerning tank modeling between primary target locations.

The NBS Cryogenics Division, with the assistance of the Mechanics and

Applied Math Divisions, is serving in a third party role under a grant

from the Maritime Administration to evaluate the accuracy of tank surveys

and tank capacity tables for ships dedicated to LNG service. This is

being done in cooperation with U.S. shipbuilders and their subcontractors

involved in the construction of LNG tankers and with involvement of ship

owners and operators and the buyers and sellers of LNG.

The NBS effort is being directed into four major areas, some of them posing unique measurement and analytical problems. The objectives of this

work are:

1) to determine the accuracy of the survey techniques (primarily

the photogrammetric techniques), as they are presently applied to locate

the primary targets.

2) to evaluate methods for modeling the tank surface and to establish checks (or errors) between the model and the actual tank surface.

3) to calculate the probable error in the tank capacity tables as obtained by numerical integration of the model, this calculation being

restricted to the empty tank at ambient temperature.

4) to evaluate the changes in tank dimensions (and resulting cor- rections to the capacity tables) due to thermal contractions and stresses

from cooling and loading with an LNG cargo. This area of study includes

the effects of possible hysteresis or changes in tank shape over a period

of time due to continual use. This last area poses some formidable measurement problems since the inside

of the tank (or the outside for that matter) is not accessible under

cryogenic conditions. If measurements are made at all, they must be done

using a remote technique.

Problem Areas. A long baseline measurement in a horizontal direction is

deemed necessary in order to minimize the estimated uncertainties in co- ordinate location. This may be difficult to do within the desired accuracy. Tape or wire measurements and microwave methods are being considered along with RF resonance methods.

Funding . January 1 - June 30, 1977.

Man-years expended 0.5

Total reporting period cost 37.5K$

Balance remaining 26.5K$

20
10. Future Plans.

1. NBS will continue to assess the ability of RF resonance measurements to give major dimensions of large empty tanks and also to

evaluate its potential as a method of gauging LNG.

2. We will continue to work with the shipbuilders to assess the effects

of loading and stresses due to thermal contractions on the projected

tank capacity.

3. NBS will complete analysis of the coordinate data as it comes from

the photogrammetric procedure and will evaluate results using independent data from the gauge rods and the redundant coordinates, in

order to complete the assessment of the empty tank survey accuracy.

21
1. Title . HEATING VALUE OF FLOWING LNG

Principal Investigators . J. A. Brennan.

2. Cost Center Number . 2756579

3. Sponsor Project Identification . Pipeline Research Committee (American

Gas Association) PR-50-48.

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

value measurements in actual applications of flowing LNG. Information

from projects currently underway by Siegwarth (cost center 2757574) on densimeters, by Haynes and Hiza (cost center 2751574) on mixture

densities and by Parrish (cost center 2750575) on LNG sampling will be

utilized where appropriate to provide state of the art information.

5. Obj ectives . The objective of this program 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 presently available calibration facilities. Therefore, a secondary objective is to establish appropriate flowmeter scaling laws.

6. Background . The LNG flow facility at NBS will be utilized to evaluate

the response of the individual elements in the heating value measurement. Different compositions of LNG will be prepared to provide a range

of densities and temperatures sufficient to determine any dependencies.

A limited amount of sampling work is included to determine the relative

importance of this parameter to the overall measurement.

Flowmeter scaling is being done utilizing the cryogenic and the water

flow facilities at NBS and private LNG peak shaving facilities.

7. Results . A. Tests at NBS.

LNG flow tests run in conjunction with the sampling project (cost center

2750575) resulted in a continuation of the discrepancies described in

the last report. These discrepancies were between the heating values

calculated from gas analysis and measured on the calorimeter. As a re- sult of those tests additional work has been done on the sampling project

on other flow facilities to try to eliminate the problems encountered.

Additional tests on the NBS flow facility are planned for the next re- porting period to verify the solutions to the problems.

The benefits from the work done on the sampling project are obvious.

Although never a part of this project, sampling has always been recognized as a vital element in the successful application of the measurement station concept. Therefore, the next series of flow facility sampling

tests will have significant importance and any information obtained will

be made available to this project.

B. Tests at Transco

The tests at Transco 's peak shaving facility have been completed and the

report is in progress. Considerable data were obtained during send outs

during January. Not only were longer runs obtained, but runs at higher

flow rates were also obtained.

All of the results will be included in a separate report now being finalized.

22
C. Test Section Installation at Southern Energy.

Test section fabrication is underway. Considerable delay has been ex- perienced in getting design problems worked out and fabrication procedures

approved

.

There are still some problems remaining with the densitometer but those

should be worked out in the near future. The densitometer problems v/ill

not hold up the delivery of the test section to Southern for installation

into the facility.

8. Problem Areas . The problems described above have resulted in delays that

have prevented the calibrations required from taking place as planned and

are now scheduled for the next reporting period. These calibrations will

consist of a water calibration of the flowmeter, a flowing liquid nitrogen test on the densitometer and a non-flowing liquid methane test on the densitometer.

The delays have also resulted in all the remaining funds being expended

so it was necessary to request an additional $15,000 to complete this

phase of the project.

9. Funding . January 1 - June 30, 1977

Man-years expended 0.5

Total reporting period costs 40.0K$

Balance remaining 0

10. Future Plans . Completion of the report of results and all the necessary

calibrations of the instrumentation for Southern's import terminal will

be done as rapidly as possible. Installation of the recording equipment

at Southern will be completed when convenient for Southern after the

changes are checked out.

23
Title . LNG DENSITY REFERENCE SYSTEM

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

Cost Center Number . 2757574, 2750161

Sponsor Project Identification . American Gas Association, Inc.,

Project BR-50-10; National Bureau of Standards

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. This effort is oriented

towards metrology, whereas the output from cost center 2751574 will provide basic reference data on pure liquids and mixtures to evaluate

methods for calculating the density indirectly.

Obj ectives . The objective of this research is to evaluate the density

measurement capability of commercially available meters. From the com- mercial meters we will attempt to select one or two capable of performance

as transfer standards, in order to provide 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.

Program and Results . The second series of densimeter tests has been completed. A final report and an updated accuracy statement for the density

reference system (DRS) are in preparation. The occasion to occasion shift

in the DRS has been eliminated, and the estimated inaccuracy of a future

measurement has been established to be + 0.076%. The densimeters tested

have been found to have satisfactory precision but some are lacking satisfactory calibrations for LNG service.

A final draft of the densimeter report is written along with a final

draft of the DRS Provisional Accuracy Statement. The review should be

completed and the reports ready for printing by August 1.

Problem Areas . The DRS is performing in a satisfactory manner but the

sample container is too small and too inflexible to permit testing some other densimeters which we would like to test.

Funding . January 1 - June 30, 1977.

Man-years expended 0.4

Total reporting period cost 25.0K$

Balance remaining 0 Future Plans. The DRS may be modified to take larger commercial densimeters'! The DRS will be used to evaluate and calibrate transfer standards

for use in calibrating densimeters at other locations. A transfer standard will be sent to Gaz de France, Paris, to intercompare our two calibration systems.

24
1. Title . LNG SAMPLING MEASUREMENT STUDY

Principal Investigators . W. R. Parrish, J. M. Arvidson and J. D. Siegwarth

2. Cost Center Number . 2750575

3. Sponsor Project Identification . LNG Sampling Measurements Supervisory

Committee

.

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 widespread acceptance in the LNG industry. Also, a standard technique has not been established for analyzing the vaporized

sample

.

5. Objectives or Goals . The objectives of this work are to evaluate existing sampling techniques appropriate to LNG systems and to recommend the

most accurate analytical technique. Only sampling devices applicable

to pipelines are being considered. The sampling techniques are judged

on

:

a) representativeness of sample,

b) insensitivity of results to composition, temperature, pressure,

degree of liquid subcooling, flow rate and operator, and

c) simplicity.

Initial evaluations will be made in a laboratory-scale apparatus; final

evaluation of the most promising sampling techniques will be performed

in the LNG flow facility.

6. Background . This work is being 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 transfer.

7. Program and Results . A. Laboratory Results

The laboratory-scale sampling tests were completed in May. It was found

that the sampling imprecision (one standard deviation) was typically

around 0.04% in the heating value; this is roughly twice the imprecision

obtained for gas analysis alone. The reason for the increased scatter

was never found. Two sampling probes, a side tap and an upstream-facing

pitot tube were tested; the side tap gave slightly more reliable results.

Of the three different sample conditioners (i.e., vaporizers) tested,

the simple heated tube vaporizer produced the best results.

The laboratory results showed that the only operating parameters that were important were the sampling rate and the time averaging of the

vaporized sample. It was found that high sampling rates are necessary

for obtaining representative samples. Samples taken without time averaging had roughly 100 times the scatter of the time averaged samples.

Variables tested, but not showing an effect on sampling precision, included

operating temperature and pressure, degree of subcooling at the sample

point (at least for greater than '\^0.3 K subcooling) and LNG flow rate.

25
The sampling precision was not affected by sampling from a LNG stream

in laminar or turbulent (Reynold's numbers of 1600 to 37,000) flow.

B. Tests Aboard the LNG Tanker El Paso Consolidated

A LNG sampling system was designed, installed and operated aboard the

El Paso Consolidated in June. The LNG sampler was put into the heater

going to the ship's stream vaporizer; a similar sampling system (excluding the sample vaporizer) was installed in the vaporizer outlet header

for collecting vapor samples. Although all of the data have not been

analyzed, a test having 7 sets of samples showed that the difference in

the average heating values of the liquid and vapor samples was 0.04%;

the estimated standard deviation was 0.045% for both types of samples.

This is only slightly greater than the estimated standard deviation of

0.03% for gas analysis alone.

C. LNG Flow Facility Tests

Final sampling tests will be made in the LNG Flow Facility at Boulder.

The variables to be considered will include the level of insulation, the

heat source for sample vaporization and the sampling rate. By combining

all of the sampling data we hope to establish a criterion for setting the

sampling rate.

. D. Gas Analysis

Previous work had established that gas chromatography is the best method

for measuring the composition of vaporized LNG mixtures. The final phase

of this work will be to recommend column configurations, determine opti- mum operating procedures and establish tolerance levels for operating

variables. Intercomparisons between two gas chromatographs and two data

processors will be made.

8. Problem Areas . None.

9. Funding. January 1 - June 30, 1977.

Man-years expended

Total reporting period cost

Balance remaining

10 . Future Plans . Objectives and Schedule: Quarter 3 4

Complete all tests and write

final report.

.75

60. K$

41. K$

26
1. Title . SURVEY OF CURRENT LITERATURE ON LNG AND METHANE

Principal Investigator . Neil A. Olien

2. Cost Center Niomber . 2759574

3. Sponsor Project Identification . 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 continuing

awareness 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 hydrogen as a future fuel. 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 134 subscriptions going to AGA

Member Companies and 154 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-152 6 THE THERMOPHYSICAL PROPERTIES OF METHANE MIXTURES - A

SELECTED BIBLIOGRAPHY. Indexed by property, system and

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

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).

27
B-152 7 PATENTS RELATING TO METHANE AND LNG TECHNOLOGY - A SELECTED

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

.

($15. 00) . Over the past six years we have distributed over 500 copies of these

and the comprehensive bibliographies.

Problem Areas . None.

Funding . January 1 - June 30, 1977.

Labor 4 . 6K$

Other Costs 1. 1K$

Total 5.7K$

Remaining 11.0K$

Future Plans . Issue 77-2 was delivered to the printer the second week

of July and should be distributed by the end of July.

28
Title . LIQUEFIED NATURAL GAS TECHNOLOGY TRANSFER

Principal Investigator . D. B. Mann

Cost Centers . 2750403, 2751403, 2752403, 2750570, 2754574, 2758574 and

2750127.

Sponsor Project Identification . Maritime Administration, Miscellaneous

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

BR 50-10; American Bureau of Shipping letter dated 21 November 1975; and

NBS-Office of Standard Reference Data.

Introduction . The liquefied natural gas program at the Cryogenics

Division of NBS- IBS/Boulder represents an investment by industry and

government agencies of over $5 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 has appeared in previous semi-annual reports. The

Maritime Administration of the Department of Commerce and the American

Bureau of Shipping have agreed 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 have agreed to sponsor the section on fluids and fluid mixtures. The project was begun on April 1, 1976.

Ob j ectives . 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 Cryogenics 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.

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 is classified into three groups by the NBS Cryogenics Division.

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

assessed, evaluated or experimentally verified by NBS.

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

29
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, all 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 form

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.

Nine structural metals have been selected with additions possible upon

consultation with the sponsors. Primary emphasis in the fluids section

will be on data for pure methane, pure nitrogen, and methane-nitrogen mixtures.

Program and Results . The distribution of the user's manual has been

unavoidably delayed over our original timetable. However, all charts

are presently at the printer and we anticipate distribution sometime in

September of this year. The first edition will include 138 charts,

8-1/2" X 11", and six 22" x 34" charts on the properties of pure fluids

methane and nitrogen. Structural materials data for aluminum alloys

(3003, 5083, 6061), invar (Fe-36Ni), nickel steels (2-1/4, 3-1/2, 5 and

9% Ni) and stainless steels (304, 304L, 310 and 316) are included in the

first edition. Elastic, thermal and mechanical properties of these

materials are presented in graphical format. Data on pure fluid methane,

on nitrogen and on methane-nitrogen mixtures are also included, and cover

thermodynamic, transport and electromagnetic properties.

Problem Areas . Delays in final preparation of print-ready copy have

hopefully been eliminated; future supplements should not suffer from

these delays.

Funding . January 1 - June 30, 1977.

Labor - man-years expended 0.5

Funds expended 43.0K$

Balance remaining (first edition) 0 Future Plans. The second year of this user's manual has been funded by

the Maritime Administration, the American Gas Association (Gas Research

Institute) and the Office of Standard Reference Data (NBS) . D. E. Diller

has accepted the general editorship of this supplement and anticipates 90

charts in the supplement. It is planned to add additional properties of

structural materials and a section on insulations. In addition, data for

pure ethane and for mixtures containing methane will also be included.

30
1. Title . omi JOINT SECRETARIAT ON LNG MEASUREMENTS

Principal Investigator . Douglas Mann

2. Cost Center Number . 2750104

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

NBS-Office of International Standards; and NBS-Cryogenics Division.

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

of Standards Cryogenics Division has, over the past five years, provided

the gas industry and interested Government agencies with properties data

on materials and fluids, instrumentation, and measurement assistance in

the support of commerce in this significant and growing segment of the

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 an 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

within the next three years;

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 19 55 to promote intergovernmental

cooperation in the field of legal metrology which relates to the com- patibility 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 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

31
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 implem.enting 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 insure 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. 13 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.

7. Program and Results . An overall scope for recommendations for LNG mea- surements was completed. The measurements would apply to both static

measurements (land based storage, marine tanker at dock site, large tanks

at dock site and highway or road trailer) and dynamic measurements (pipeline) . It was suggested then that the measurements be divided into two

areas: static and dynamic mass measurements and static and dynamic gross

heating value measurements.

Recent developments, such as the adoption by the National Conference on Weights and Measures of the model code "Cryogenic Liquid Measuring Devices,"

may affect the manner in which LNG measurements are treated by OIML. A

similar code, developed by European industry, indicates that enough interest is developing in this high technology area that recommendations

by OIML should not be limited to LNG, but should include other cryogenic

fluids. Representatives of NBS will meet with PTB (West Germany) and

SIM (France) to explore this possibility during August.

8. Problem Areas . None.

9. Funding . January 1 - June 30, 1977.

Labor - Man-years expended 0.1

Funds expended 11.0K$

Balance remaining 11.0K$

10. Future Plans . Two areas will be explored. The first concerns expanding

the scope of the LNG measurements to include other cri^ogenic fluids and

thereby taking advantage of existing codes and standards within the U.S.

and Europe. Second, continued development of the scope for LNG measurements to identify recommendations already available under OIML and those

which must be written separately.

32
1. Title . FEDERAL POWER COmiSSIOfJ CONSULTATION

Principal Investigators . D. B. Chelton, T. R. Strobridge and A. F.

Schmidt

.

2. Cost Center Number . 2750404

3. Sponsor . Federal Power Commission - Bureau of Natural Gas -- letter

agreement dated 4 June 197 3.

4. Goals . The Cryogenics Division will provide consultation and advisory

services to the Federal Power Commission on the cryogenic safety and

the design aspects of current applications before the FPC for authorization of LNG terminal and storage facilities. These services cover properties of cryogenic environments, insulation systems, cryogenic

safety, thermodynamics, heat transfer, instrumentation, and cryogenic

processes such as refrigeration and liquefaction.

5. Background . Cost Center initiated July 7, 1973.

6. Program and Results . The status of those facilities presently under

the jurisdiction of the Federal Power Commission and subject to our review are outlined in the following table.

Elements of the facilities that are subject to review are the land-based

cryogenic storage tank components, bounded by the tanker or barge, the

inlet and distribution pipelines. These include, but are not limited

to the transfer lines, the storage tanks, the vaporizers and the process

piping as it interacts with the storage tanks. It is essential that the

reviews cover the operation, maintenance and emergency procedural

philosophies for each terminal. Based upon these studies, reports are submitted to the staff of the FPC setting forth the technical evaluations

and conclusions on each proposal.

Emphasis is placed on the safety aspects of the facilities including

their possible interactions with the surrounding areas. The impact of

engineering design such as appropriate use of existing technology and

material selection for structural integrity must be assessed. The

basis of review includes various codes and standards, prior experience,

precedent and engineering knowledge. Vapor cloud generation and plume

dispersion is considered a subject beyond our area of expertise.

7 . Funding

.

FY 77 Allocation 70K$

Expended January 1, 1977-June 30, 1977 30K$

8. Future Plans . At the present time there are several pending

applications , but detailed information is not yet available. It is

anticipated that additional facilities will be reviewed as applications

are made to the Federal Power Commission.

33
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35
NBS-1 14A (REV. 7-73)

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. PUHI.ICATION OR RI{PORT NO.

NBSIR 77-864

2. Gov't Accession

No.

3. Recipient's Accession No.

4, TITLF AND SURTITI,K

1 Tniimrn matiidai haq df^padpi-i at thf matthmai

BUREAU OF STANDARDS

5. Publication Date September 1977

6. Performing Organization Code

275.

7. AUTHOR(S)

D. E. Oilier, Editor

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No. 2750104

11. Contract/Grant No.

12. Sponsoring Organization Name and Complete Address (Street, City, State, ZIP)

Same as Item #9.

13. Type of Report & Period Covered Semi-ApHual

1 Janudry-30 June 1977

14» Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

16. ABSTRAC l (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here.)

Twenty-six cost centers, supported by six other agency sponsors in addition to

MBS, provide the basis for liquefied natural gas (LNG) research at NBS. During this

six-month reporting period the level of effort was over 20 man-years/year with funding

expenditures of over $500,000. This integrated progress report, to be issued in

January and July, is designed to:

1) provide all sponsoring agencies with a semi-annual and annual report on the activities of their individual programs;

2) inform all sponsoring agencies on related research being conducted at the

Cryogenics 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 contents of this report will augment the quarterly progress meetings of some sponsors, but will not necessarily replace such meetings. 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 .

17. 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)

Cryogenics; liquefied natural gas; measurement; methane; properties; research.

18. AVAILABILITY Unlimited

[^n For Official Distribution. Do Not Release to NTIS

Order From Sup. of Doc, U.S. Government Printing Office Washington, D.C. 20402, SD Cat. No. C13

I j Order From National Technical Information Service (NTIS)

Springfield, Virginia 22!')1

19. SECURITY CLASS

(THIS REPORT)

UNCL ASSIFIED

20. SECURITY CLASS

(THIS PAGE)

UNCLASSIFIED

21. NO. OF PAGES

22. Price

USCOMM-DC 29042-P74