A new method for scale-up of solvent-based post-combustion carbon capture process with packed columns

Abstract

Solvent-based post-combustion carbon capture (PCC) with packed column is the most commercially ready CO2 capture technology. To study commercial-scale PCC processes, validated pilot scale models are often scaled up to commercial-scale using the generalized pressure drop correlation (GPDC) chart which requires assuming the column pressure drop. The GPDC method may lead to either over-estimation or under-estimation of the column diameter. In this paper, a new method for estimating the packed column diameter without assuming the pressure drop has been proposed and used for model scale-up. The method was validated by scaling between two existing pilot plant sizes. The CO2 capture process was simulated in Aspen Plus® and validated at pilot scale. The validated model was scaled up to commercial CO2 capture plant capable of serving a 250 MWe combined cycle gas turbine power plant using the new method proposed in this study. The results obtained from the scale-up study were compared to those obtained when the GPDC method was used to design the same commercial CO2 capture plant. The results showed that the GPDC method overestimated the absorber and stripper diameter by 1.6 % and 8.5 % respectively. Process simulation results for the commercial-scale plant showed about 2.12 % and 5.63 % lower solvent flow rate and reboiler duty with the proposed method. Therefore, the capital and operating costs for the process using the newly proposed scale-up method could be lower based on our estimates of the column dimensions, solvent flow rate and specific reboiler duty.