INL RESEARCH & DEVELOPMENT

Science

New LNG Plant Technology

Continued on back

As liquefied natural

gas (LNG) advances

toward widespread

commercial use, the prospect

of producing it where it will

be distributed commercially

has become increasingly

attractive.

An invention by the LNG

research team at the U.S.

Department of Energy’s Idaho

National Laboratory has made

this prospect a reality by

developing a small-scale

methane liquefaction plant.

Small-scale liquefaction

plants are advantageous

because their compact size

enables the production of

LNG close to the location

where it will be used. This

proximity decreases transportation and LNG product costs

for consumers.

The small-scale LNG plant

also allows localized peakshaving to occur – balancing

the availability of natural gas

during high and low periods

of demand. It also makes it

possible for communities

without access to natural gas

pipelines to install local

distribution systems and have

them supplied with stored

LNG.

INL liquefaction technology

is designed to draw natural

gas from a transmission

pipeline at a point where the

pressure is dropped to

accommodate commercial

distribution. The plant is

powered mainly by the energy

created through this pressure

drop. As the gas enters the

plant, some of it is allowed to

expand, and as it expands, it

cools. This allows the process

to use the natural gas as a

coolant in the liquefaction

process.

A plant installed in Sacramento removes contaminants

from the methane stream as it

progresses through the plant.

The stream is injected with

methanol, which bonds to the

water. When the temperature

drops to the point where the

methanol vapor becomes

liquid – the water and methanol are separated out of the

methane stream. During the

final cooling of the LNG

product, solid CO2

 is formed

and separated from the

methane stream.

Small-scale liquefied natural

gas plants, that draw from

existing natural gas lines, are

becoming increasingly

attractive.
INL RESEARCH & DEVELOPMENT

05-GA50193-62

This significantly decreases

the work involved with precleaning the methane. The

water/methanol mix and solid

CO2

 are vaporized into the

distribution line without

significantly changing the

BTU of the line.

The natural gas is liquefied

and moved into a storage tank

where it stays until used,

trucked away, or re-injected

into the pipeline.

The Sacramento plant is

designed to interact with the

distribution line at a pressure

let-down station, remove

water and CO2

, and liquefy

10-20% of the gas entering

the plant. Other plant models

are being designed to adapt to

higher CO2

 concentrations,

nitrogen content, higher and

lower pressure distribution

lines, connections at non letdown points, and to liquefy a

higher percentage of incoming gas.

No gas is consumed by the

plant during this process. The

plant requires little oversight,

and future plants may require

very little manual operation, if

any.

A full-scale methane liquefaction plant can require hundreds of acres and cost

billions of dollars. A smallscale liquefaction plant can fit

into a cargo container at a cost

of less than two million

dollars.

For more information

Technical Contact:

Bruce Wilding

(208) 526-8160

Bruce.Wilding@inl.gov

Technology TransferContact:

David Anderson

(208) 526-0837

David.Anderson@inl.gov

The Sacramento plant was

developed and designed under

the terms of a Cooperative

Research and Development

Agreement (CRADA) with

Pacific Gas and Electric

Company and Southern

California Gas Company. The

technology has been successfully tested and is now

available to be licensed for

commercial manufacturing.

INL is a multiprogram

national laboratory dedicated

to supporting DOE’s missions

in energy and national

security, environmental

quality, and science.

Continued from front

The first LNG demonstration plant was constructed in Sacramento, California. After having been

successfully tested, the technology is available for licensing and commercial manufacturing.

INL is a U.S. Department of Energy

national laboratory operated by

Battelle Energy Alliance