CO₂ Capture From Flue Gas Purification Process Simulation And Parameter Optimization

In oil field, the carbon dioxide flooding technology represent the forefront of the development direction for EOR. It not only enhanced oil recovery but also reduce CO₂ emissions. At present this technology are not used widly, because the amount of CO₂ used for EOR is very little. It is a bottleneck of CO₂ enhanced oil recovery technology that how to effectively obtain high purity and a large number of CO₂. Coal-fired boiler emissions a great quantity of flue gas, and it is main emission source of CO₂. Obtaining high purity CO₂ from flue gas can not only meet the demand for CO₂ EOR, but also reduce CO₂ emissions.This topic describes the methods of recovery CO₂ from flue gas, for example Absorption separation, Adsorption separation, Membrane separation, Cryogenic distillation and so on. Contrast and analysis the advantages and disadvantages of various methods. MEA has advantages of strong absorptive capacity, faster reaction rates, and it is suit for recovery CO₂ from flue gas of atmospheric pressure and low CO₂ content. The issue adopts chemical absorption method with MEA.This paper studied the reaction mechanism of recoverying CO₂ using alcohol amine. Discussed the calculating method of alcohol amine-CO₂ reaction rate, and experimental study single alcohol amine and mixed amines absorpting CO₂. Then concluded that: (1) The reaction rate of primary amine with CO₂ and secondary amine with CO₂ is far greater than the reaction rate of tertiary amine with CO₂ under the same conditions. (2) The rate of amine solution to absorb CO₂ is MEA>DEA>MDEA at the same concentration. (3) Increase amine concentration can increase the absorption rate of CO₂(4) Adding DEA or MEA to MDEA will increase the absorption rate of CO₂.In this paper, useing MEA as the absorption medium. Simulate CO₂ absorption and desorption processes in the absorption tower and desorption tower by AMSIM. Identified the factors that impact CO₂ absorption and desorption. Obtained the best operating conditions, and concluded that: (1) CO₂ absorption rate increase with MEA concentration increasing. (2) When MEA solution's flow rate is low, increasing it's flow rate can enhance CO₂ absorption rate.(3) CO₂ absorption rate approximately linear decrease with absorption temperature increasing.(4) CO₂ absorption rate increases with the absorption pressure increasing. (5) Increasing packing height can increase CO₂ absorption rate. (6) Increasing reflux ratio will help improve the quality of lean solution regeneration. (7) Increasing the pressure of reboiler will help improve the quality of lean solution regeneration.( 8) The load of CO₂ in lean amine will decrease with packing height increasing. (9) Heat load of reboiler in rich amine desorption processes will increase when add MEA or DEA to MDEA.