METHOD AND APPARATUS FOR NATURAL GAS PARTIAL LIQUEFACTION Russian patent published in 2003 - IPC

FIELD: liquefaction of pure gases and gas mixtures. SUBSTANCE: method involves initial cooling and dewatering of pressurized natural gas; expanding of part of direct flow and its mixing with reverse flow; cooling, throttling and separating of direct flow into vapor fraction and liquid fraction into accumulator/separator for liquid-vapor mixture; dividing of vapor fraction into two vapor flows; feeding of first vapor flow through pressure regulator and using of first vapor flow for cooling of direct flow; condensing of second vapor flow for the second time by heat-exchanging with liquid fraction directed to reverse flow; throttling of condensed fraction into liquid natural gas accumulator along with vapor fraction removing; providing necessary temperature difference for condensation by increasing of vapor fraction pressure or by decreasing of liquid fraction pressure. EFFECT: reduced contents of high-boiling components and carbon dioxide in resultant liquefied natural gas and low cost of natural gas purification process. 4 cl, 2 dwg