ANALYSIS OF LIQUEFIED METHANE PRODUCTION TECHNOLOGY DEPENDING ON METHANE PURITY AND PRODUCTION VOLUME

摘要

Use of liquefied methane (LM) as an effective and ecologically clean fuel in space-rocket, aerospace, and aviation systems is a highly important step toward further development of these systems. According to expert estimate, the volume of LM use ranges from 2000 to 4000 tons a year in space-rocket technology and may be many times more in aviation. Furthermore, the rate of LM use in road, rail, and marine transports, public utilities, etc., has been rising. Considering the prospects of LM consumption, at least over the next decade, as well as the foreign experience, it should be possible to produce LM in cryogenic liquefaction plants up to 40 tons/h in capacity. In particular, plants with methane producing capacities of up to 5 tons/h should be built at gas-distributing stations (GDS) and up to 1 ton/h, at automobile gas-filling compressor stations (AGFCS). The choice of the liquefaction cycle (throttle, expansion, and cascade with several refrigerants and with a mixed refrigerant) depends on how far the energy consumption is reduced. It depends also on the purpose and capacity of the plant, composition and pressure of the raw natural gas, and LM specifications (pressure, temperature, composition, etc.). Let us analyze natural gas liquefaction technologies in terms of meeting methane quality requirements for various consumers, including those for space-rocket technology where practically pure methane is used. The LM quality attained in liquefying-cum-separating plants must be maintained by appropriate LM handling technology in transportation systems from the filling point of the plant to the consumer's tank.