NATURAL GAS PREPARATION METHOD Russian patent published in 2000 - IPC

FIELD: automobile gas- filling compressor stations. SUBSTANCE: to prepare natural gas for charging into cylinders, delivered natural gas is preliminarily cleaned of condensed moisture and mechanical admixtures and compressed. Gas is subjected to adiabatic expansion fully or partially and separated from condensed moisture. Compressed gas is cooled in two steps. In first step gas obtained after second step is used as cooling agent. Expanded gas is used in second step. Condensed moisture is separated after each step. Natural gas is compressed due to external operation source and work of adiabatic expansion. Natural gas is also compressed only due to adiabatic expansion work. Compressed gas at initial pressure is cooled with part of gas obtained after expansion with separation prior to moisture compression. After using of expanded gas, the latter is directed to lower-pressure gas-transporting pipelines. In case of external source of operation, compression is performed in two steps. Expansion work is used in first step and external source operation, in the second prior to expansion, gas at user's mains pressure is compressed up to excessive pressure of at least 0.3 MPa. Gas expansion is performed up to final temperature of -35 - -55 C. When gas is compressed due to expansion work gas pressure after expansion is reduced by throttling. Adiabatic expansion is performed in rotary laminated machine. Given method makes it possible not to use expensive adsorbents which need constant regeneration for gas drying. EFFECT: enhanced efficiency. 8 cl, 2 dwg