Patent ID: 8673062
Filing Date: 2014-03-18
Classification: B01D,C10L

Abstract:
1. A method of removing acid gases from raw gas, the method comprising the steps of: (a) supplying the raw gas to an absorption column having a head and a sump where the raw gas is contacted with a physical absorption agent, having a boiling point lower than 100° C. at atmospheric pressure, under elevated operating pressure at 5 to 150 bar to load the physical absorption agent with acid gases and usable gases and drive the physical absorption agent loaded with acid gases and usable gases from the absorption column at the sump while drawing off at the head of the absorption column a purified top gas containing up to a few ppm of acid-gas components; (b) feeding the loaded physical absorption agent to a high-pressure stripping column operated at a pressure of 5 to 150 bar and having a head and a sump and at the head of the high-pressure stripping column driving out usable gases coabsorbed in the physical absorption agent with stripping steam to obtain head steams containing the usable gases and the physical absorption agent, and drawing off the driven out usable gases from the head steams at the head of the high-pressure stripping column, and to obtain at the sump physical absorption agent loaded with acid gases; (c) liquefying the physical absorption agent contained in the head steams, and recycling the liquefied physical absorption agent contained in the head steams to the high-pressure stripping column; (d) feeding the physical absorption agent leaving the sump of the high-pressure stripping column and still loaded with acid gases to a high-pressure regeneration column operated at a pressure of 5 to I00 bar and having a head and a sump; (e) separating and drawing off acid gases at the head of the high-pressure regeneration column such that at least a portion of the acid gases accumulates at the head of the high-pressure regeneration column as a liquid; and (f) drawing off regenerated physical absorption agent at the sump of the high-pressure regeneration column and recycling regenerated physical absorption agent to the absorption column.