| 摘要 |
PURPOSE:To recover LPG and NGL from a natural gas and a gas followed by petroleum in high yield with saved labor, by partially pulling out a rising gas in a methane removing column, compressing, cooling, liquefying the gas forming reflux and feeding to the top of methane column. CONSTITUTION:A raw material gas 1 is cooled, partially condensed into a vapor-liquid two-phase liquid, separated into a gas 8 and a liquid 9 by a high- pressure vapor-liquid separator 7, the gas 8 is expanded, partially condensed, a vapor-liquid mixed fluid thereof is fed to the top zone of a methane removing column 13. On the other hand, the liquid 9 is subjected to adiabatic expansion and pressure reduction, partially vaporized, heated and then fed to a lower position than the above-mentioned vapor-liquid mixed fluid feed position of the column 13. Then a cooled gas 23 is taken out from the top of the column, heated, compressed, sent to another process, a cooled gas 17 rising in the column is partially pulled out from a higher position than the above-mentioned vapor- liquid two-phase fluid feed position, pressurized, cooled, liquefied, expanded and subjected to pressure reduction to give reflux 22, which is supplied to the top of the column and a liquid 14 from which methane is removed is taken out from the bottom of the column. |
