CO2 removal from industrial gases is a typical operation that has direct effect on production rate and its cost of operation. Every process industry uses fossils fuel to generate chemical products and energy, ultimately produce tons of carbon dioxide. In case of industrial gases production like synthesis gas, which is the intermediate in the production line, should be free from carbon dioxide to improve the conversion in the reactor.
We discuss here about one of the famous process i.e Giammarco vetrocoke process, it is used for CO2 capture operation mostly in petrochemical industries and see how the equipments are arranged in the flowsheet of CO2 removal system, connected with various unit operations.Carbon dioxide removal from the process gas is done by absorption unit operation using alkaline solution as absorbent. This process uses hot potassium carbonate solution absorbent along with vanadium pentoxide (V2O5) corrosion inhibitor and glycine (NH2CH2COOH)Process starts from absorption tower, physical contact of process gas and absorbent happens in this tower. CO2 transfers from gas phase to liquid phase. Countercurrent flow pattern through packed beds improves the rate of absorption by providing good surface area and contact time. Mass transfer accomplished by following chemical reactions
- CO2 + H2O ↔ H2CO3
- K2CO3 + H2CO3 ↔ 2KHCO3
Purified gas contains less than 1000 ppm CO2.The second step of the process is regeneration of the absorbent for reuse. By the technique of flashing to low pressure most of the CO2 is separated. Hydraulic turbine system is used between the high pressure and low-pressure columns to recover the energy.Steam stripping is done for further removing the CO2 from the absorbent. Outlet stream from the top of the two regeneration towers were cooled to obtain the condensate for steam generation and CO2 is vented out or used in elsewhere in the process industry.