Critical parametric study of circulating fluidized bed combustion with CO2 chemical absorption process using different aqueous alkanolamines

Abstract

The aim of this article is to evaluate the integration of the CO2 chemical absorption process in the circulating fluidized bed combustion (CFBC) technology using coal. In this paper, different kinds of amine solvents will be used: mono-ethanolamine – primary amines; diethanolamine – secondary amines, and blends of primary and secondary amines. The experimental results (the following parameters have been studied: the concentration in the solvent of the mono-ethanolamine (MEA), diethanolamine (DEA) and blended MEA–DEA, the number of stages in the absorber unit, and the liquid and flue gases (L/G) ratio) obtained on the CFBC pilot installation were validated with ASPEN Plus – Hysys 3.2. Therefore, for the CO2 capture process efficiency of 90% and for 30 wt.% MEA in solvent, the L/G ratio was 1.13 molMEA/molflue gas. In this case, the amount of the thermal energy required for the solvent regeneration was 2.37 GJ/tCO2. The optimal value of the number of stages for the absorber unit was 12 for a solvent temperature of 40 °C at the top of the absorber unit and the ratio L/G of 1.15 mol CO2/mol amine.