Modeling analysis of energy requirement in aqueous ammonia based CO2 capture process

Abstract

Aqueous ammonia is a promising alternative absorbent for CO2 capture from the flue gas of coal-fired power plants. The efficiency penalty of aqueous ammonia based CO2 capture process, however, is considerably heavy, resulting from the energy requirement for CO2 regeneration and NH3 abatement cycle. The paper focused on the whole process including CO2 absorption, CO2 regeneration, CO2 compression, NH3 abatement and NH3 recovery process, and analyzed the effects of operating parameters on the energy requirement of this process with a validated and reliable model. The sensible heat, stripping heat and desorption heat were calculated to gain insights into the regeneration process. The orthogonal analysis method was then adopted to find out the achievable minimum energy requirement for CO2 capture. The minimum energy requirement was identified as 2.89MJ/kg CO2 for CO2 regeneration process and 4.07MJ/kg CO2 for the whole process.