Removal of carbon di:oxide from natural gas - esp. from wells near sea coast, by washing with sea water in submarine absorber

摘要

A process for removing water-sol. impurities from gas streams is esp. suitable for removing CO2 (pref. present as 20-95 vol.%) from natural gas from a well near the sea coast. An absorbing vessel contg. sea water is immersed in the sea, on or near the sea bed. A stream of natural gas enters at the bottom and, in rising, induces a parallel inlet flow of sea water. CO2 is absorbed, and the CO2-contg. water is rejected into the sea, pref. at a point where the sea water density is at least .0002 g/ml less than that of the effluent, so that the latter disperses over a wide area of the sea. The purified natural gas is collected for further processing. Costly absorbents and plants are not required. The equipment is cheap in that (a) a high-pressure vessel is not needed (the operating pressure being close to the local hydrostatic pressure); and (b) the absorbing water flow is induced and pumps are not required. Pipes and tanks are not necessary for the CO2 removed. The purified gas is of much lower vol. than the crude gas, so that transport costs are reduced: this is important if CO2 is absorbed at a well far off shore.