Method for selective removal of hydrogen sulphide and CO2 from crude gas

Method for selective removal of hydrogen sulphides, organic sulphur components and CO2 from crude gases, by using a first absorption stage (41) and a second absorption stage (49) for separating almost pure CO2 and using a desorption stage (50) for extracting a gas rich in hydrogen sulphide, whereby the regenerated absorbing substance from the desorption stage (50) is again guided back to both the absorption stages (41, 49), whereby as absorbing substance one uses a chemically non-active solvent, wherein the absorption agent enriched with hydrogen sulphide, organic sulphur compounds and CO2 and coming out of the first absorption stage (41), finds itself at an increased pressure between the pressure of the absorption column (41) and the pressure of the desorption column (50), and is pre-heated with the hot-regenerated solution (12) coming from the desorption stage (50) in a heat exchanger (44), and is then de-stressed at a selected pressure greater than the increased pressure in a high pressure flash container (47), whereby the gas flow released at the increased temperature is cooled in a condenser (48) and then guided to the second absorption stage (40), in which the sulphur components are completely removed with the help of (already mentioned) the part-flow the regenerated absorption agent (15, 16, 17) coming from the desorption stage (50), whereby the absorption agent is guided back (26/27) out of the second absorption stage (49) into the desorption stage (50);

• wherein the enriched absorption solution leaving the high pressure flash container (47) is de-stressed in a low pressure (56), whereby the flash gas along with the flash gas coming out of the flash stage (55) is guided to the second absorption column (45) with the help of a common compressor (58), and whereby the absorption solution leaving the low pressure flash (56) is guided on to the head of the desorption column.