Patent GB-1042185-A (GB)
Title: Processes for the separation of carbon dioxide from gas mixtures
IPC: C01B32/50
Filed: 1963-09-11
Abstract: Carbon dioxide is removed from a gas mixture by a process which includes circulating an absorption medium for CO2 through (a) an absorption tower in which the gas mixture is turbulently mixed with the absorption medium by being drawn through nozzles into the medium, (b) a separator in which the other gases are separated from the reaction medium, (c) a regeneration tower where a stripper gas, e.g. air is drawn through nozzles and thus is turbulently mixed with the absorption medium and (d) a separator in which the stripper gas and stripped CO2 are separated from the absorption medium which is recirculated to the absorption tower, the ratio of the rates of supply to the absorption tower of absorption medium and gas mixture and to the regeneration tower of absorption medium and stripper gas being such as to maintain liquid columns permeated by bubbles in the absorption tower and regeneration tower respectively and to maintain a temperature above ambient temperature, e.g. 30 DEG  to 75 DEG  C. throughout the cycle, at least the major part of the increase in temperature above ambient being obtained by the pumping energy required for circulating the absorption medium.  The absorption medium may be carbonate, pure water or organic solvents, e.g. ethanolamine solutions.  The volume of the absorption medium is at least 1/6 of the effective volume of the gas mixture.  The pressure of the gas stream upstream of the absorption may be raised by a compressor to the range of from 1 to 50 atmospheres gauge. Regeneration may be carried out at a pressure above atmospheric, but usually absorption is carried out at elevated pressure and the regeneration at approximately atmospheric pressure. Examples of gas mixtures from which CO2 may be separated are CO2-enriched air used for fruit stores and synthesis gas derived, e.g. from carbon in a water gas plant or from petroleum by cracking and intended for ammonia synthesis.ALSO:Carbon dioxide is removed from a gas mixture by a process which includes circulating an absorption medium for CO2 through (a) an absorption tower in which the gas mixture is turbulently mixed with the absorption medium by being drawn through nozzles into the medium, (b) a separator in which the other gases are separated from the reaction medium, (c) a regeneration tower where a stripper gas e.g. air is drawn through nozzle and thus is turbulently mixed with the absorption medium and (d) a separator in which the stripper gas and stripped CO2 are separated from the absorption medium which is recirculated to the absorption tower, the ratio of the rates of supply to the absorption tower of absorption medium and gas mixture and to the regeneration tower of absorption medium and stripper gas being such as to maintain liquid columns permeated by bubbles in the absorption tower and regeneration tower respectively and to maintain a temperature above ambient temperature e.g. 30 DEG to 75 DEG C., throughout the cycle, at least the major part of the increase in temperature above ambient being obtained by the pumping energy required for circulating the absorption medium.  The absorption medium may be carbonate, pure water or organic solvents e.g. ethanolamine solutions.  The volume of the absorption medium is at least 1/6 of the effective volume of the gas mixture.  The pressure of the gas stream upstream of the absorption may be raised by a compressor to the range of from 1 to 50 atmospheres gauge. Regeneration may be carried out at a pressure above atmospheric, but usually absorption is carried out at elevated pressure and the regeneration at approximately atmospheric pressure.  Examples of gas mixtures from which CO2 may be separated are CO2 enriched air used for fruit stores and synthesis gas derived e.g. from carbon in a water gas plant or from petroleum by cracking and intended for ammonia synthesis.