| 摘要 |
1,131,989. Separating gases. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 22 Dec., 1966 [24 Dec., 1965], No. 57394/66. Heading B1L [Also in Division C5] Impurities, such as H 2 S, SO 2 , CO 2 , COS, NH 3 or amines, present in scrubbing solvents which have been contracted with such gases or vapours as air, natural gas, combustion products of coal or oil, refinery gas, town gas, coke oven gas, water gas, H 2 , CO, N 2 , O 2 , water vapour and light hydrocarbons such as propane and propylene, are separated from gas or liquid residues of the gas or vapour being treated which are present in the solvent by treating the impurity-containing solvent at a pressure lower than that obtaining in the scrubbing zone with a second quantity of solvent in the presence of more of a gas or liquid which is to be similarly processed. As shown, gas or vapour stream 1 flows in countercurrent to solvent stream 3 in column 2 maintained at 7-70 kg./cm<SP>2</SP>, scrubbed gas or vapour leaving at 4. Solvent rich in impurities and containing residues of the gas or vapour leaves by line 5 and passes to column 18, which is at a lower pressure than column 2, where it encounters a rising stream 19 of a gas or liquid to be scrubbed and a falling stream 16 of fresh scrubbing solvent. Impurity-free gas or liquid leaves at 20, while laden solvent passes by line 21 to stripper 13, the impurities leaving at 15. Commonly, the principal impurity is H 2 S, in which case stream 15 is desirably treated with an oxygencontaining gas so as partially to oxidise the H 2 S to elementary sulphur. In both scrubbing zones, the temperature is suitably maintained at 25-135‹C, preferably 30-80‹C. A number of conventional solvents are listed as suitable scrubbing media for particular purposes; an especially suitable one comprises by weight 1-15% water, 15-35% diisopropanolamine and 50-84 % sulpholane (cyclotetrahydromethylene sulphone). |
