A study of the CO_2 capture pilot plant by amine absorption

摘要

A pilot plant for CO_2 recovery of 2 ton-CO_2/day from flue gas emitted from a 500 MW coal fired power plant was tested with aqueous amine absorbents. Based on a chemical absorption/regeneration process with 30 wt% aqueous monoethanolamine (MEA) solution, we studied the CO_2 recovery as a function of flow rate and input location of absorbent, pressure and temperature of stripper, and temperature of flue gas. Experimental data include the temperature profile of the absorber/stripper and CO_2 lean/rich loading values, which remained stable during the operation. We evaluated the energy requirement for regeneration of aqueous amine and the degree of CO_2 removal. While regeneration energy of aqueous amine increased with an increase in flue gas temperature and stripper pressure, it decreased with an increase in injection height of absorbent. The optimum point in flow rate of absorbent was 1300 kg/h in 350 Sm~3/h flue gas. The regeneration energy using 30 wt% MEA solution was 3.92 GJ/ton CO_2 in 90% CO_2 removal, flue gas temperature of 40 ℃, stripper pressure of 0.5 kgf/cm~2 and L/G ratio of 3.7 kg/Sm~3. In addition, corrosion rate of the pilot plant were measured in six points. It is the largest as 79.11 mpy in the bottom of the stripper tower.