LOW-TONNAGE PRODUCTION OF LIQUEFIED NATURAL GAS

Gas motor fuels production is one of the promising areas of natural gas processing and is aimed at obtaining fuel gases for the energy supply of municipal, industrial and transport enterprises, including through the "virtual pipe" gas supply system. The feasibility of obtaining gas motor fuels for the local market is determined mainly by logistical and marketing considerations.

 

The construction of autonomous packaged LNG production plants with a capacity of up to 12 tons/hour is necessary in order to:
• expand the use of gas motor fuel in transport by means of autonomous gas supply to filling infrastructure,
• intensify gasification of the regions of the Russian Federation due to autonomous gas supply to consumers, the construction of gas pipelines to which is economically inefficient,
• compensate uneven gas consumption due to gasification of consumers with a seasonal peak in the opposite phase to traditional consumers (motor-and-tractor equipment, water transport, agriculture),
• obtain additional profit from the sale of products on the domestic energy market,
• increase the load of existing gas pipeline-branches and gas pipeline-branches under construction.

 

 

PROCESS TECHNOLOGY

 

 

 

 

Block diagram of AMS LNG
1,2,3 – compressors, 2a – compressor drive,
2b – adsorption treatment unit, 4 – dehydration unit,
5, 6, 7 – heat exchangers,
8, 9 – reducing device,
10 – LNG separator

 

 

 

The autonomous low-tonnage natural gas liquefaction station (AMS) is designed for waste-free production of LNG from natural gas from low- and medium-pressure gas pipelines of regional gas transmission systems. It does not require connection to external power grids.

 

Description of the block diagram: natural gas is compressed by compressor 1 to 5 MPa, treated to remove CO2 and dehydrated in block 4, mixed with the return gas and divided into two streams, which are cooled in heat exchangers 6 and 7, mixed and reduced to 0.1 - 0.8 MPa in device 9, the resulting gas-liquid mixture is separated in separator 10 into liquefied natural gas removed from the unit and the return gas, which is heated in heat exchanger 7, one part is sent as fuel to drive 2a of compressor 2, and the main part is compressed by compressor 3 and sent to the compressed natural gas stream downstream of block 4. The multicomponent refrigerant (MCR) circulates in a closed circuit through heat exchanger 6 using compressor 2 with cooling in refrigerator 5 by refrigerating machine 2b, operating due to the heat of the exhaust gases of drive 2a, and reduction in device 8.

 

FEED
Combustible natural gas according to Gazprom company standard STO 089-2010

P=0.6-5.5 MPa, T= minus 20 (winter) – plus 20 °C (summer)

 

 

PRODUCTS
Combustible liquefied natural gas according to GOST R 56021-2014

P=0.4-0.8 MPa, T= minus 126-138 °C,

Molar fraction of methane = 80, min, LHV=31.8-36.8 MJ/nm³

Fuel gas for GEPP according to GOST 5542-2014

P=0.4 MPa, T= 10-40°C, LHV=31.8-35.0 MJ/nm³

 

 

CHARACTERISTICS

 

Gas consumption, summer/winter, nm³/hour	4650/4560
LNG production, t/hour	3,0
Liquefaction factor, summer/winter, %	94/96*
Energy consumption of own production, kW/kg of LNG	0,23**
Vent losses	NO
Electricity consumption by third parties	NO

 

CHARACTERISTICS AND FEATURES

 

AMS LNG-3 unit is designed to produce combustible liquefied natural gas of grade B0 ("Б0") according to GOST R 56021-2014 as fuel for internal combustion engines and power plants.

• Block-modular design
• Complete autonomy, no connection to an external power source is required
• No waste and vent loss
• High average annual liquefaction factor of 95% provided by the automatic control of the multicomponent refrigerant composition and the use of trigeneration.

 

Energy efficiency exceeds the indicators of similar units by 2 - 3.5 times