A comparative study of novel activated AMP using 1,5-diamino-2-methylpentane vs MEA solution for CO2 capture from gas-fired power plant

Abstract

Bench-scale pilot plant study of AMP and 1,5-diamino-2-methylpentane (DA2MP) blend for CO2 capture from gas-fired power plant is investigated. The concentration of the amine blend is 2 kmol/m3 AMP-1.5 kmol/m3 DA2MP while that of single solvent MEA is 5 kmol/m3. Comparative analysis was based on CO2 absorption efficiency (%), absorber mass transfer coefficient (KGav(ave), kmol/kPa h m3), desorber mass transfer coefficient (KLav, h−1), rich amine loading (αrich, mol CO2/mol amine), lean amine loading (αlean, mol CO2/mol amine), cyclic loading (CL, mol CO2/mol amine), cyclic capacity (CC, mol CO2/L-amine soln.), CO2 absorption rate (rabs, g-CO2/h), and regeneration energy (Qreg, GJ/tonne CO2). The contribution of sensible energy (Qsen, GJ/tonne CO2), vaporization energy (Qvap, GJ/tonne CO2), and desorption heat (ΔHdes, GJ/tonne CO2) towards Qreg was also investigated. Results showed that the AMP-DA2MP blend possess higher KGav(ave) (11.66%), KLav (7.67% higher), and CO2 absorption efficiency (4.66% higher) than MEA. Also, the superior cyclic loading (51.5%) and cyclic capacity (6.7%), and lower regeneration energy (13.8% lower) was observed for the AMP-DA2MP blend. The desorption heat (ΔHdes) was the major contributor to the Qreg of both amine systems however the ΔHdes of AMP-DA2MP was 23% lower than MEA. It was noticed that though the water concentration of the amine blend (60.7 wt%) is lower than MEA (70 wt%), the vaporization energy of the amine blend was 32.9% higher than MEA. Therefore, besides the amount of water concentration, higher desorber temperature profile, amine solvent vapor pressure and boiling point also increases the vaporization energy. The results is a revelation of possible reduction in capital cost and operating costs for the AMP-DA2MP blend compared to the standard MEA.