Dynamic Study of Carbon Dioxide Absorption Using Promoted Absorbent in Bubble Column Reactor

Abstract

Abstract-The most common process to remove carbon dioxide from natural gasand the flue gasses is absorption into suitable solvents. Absorption of carbondioxide are studied experimentally in this work using bubble column reactor (glasscylindrical (QVF) of 7.5 cm i.d. × 140 cm height), where different types ofabsorbent (30%MEA, 30%K2CO3), promoter types (organic(piperazine)andinorganic(amino acids)) and concentrations were examined over a wide range ofgas flow rate cover homogeneous to transition flow regime at ambient temperatureand atmospheric pressure. The results showed that the dissolved gas undergoes apseudo-first order reaction, and the optimum superficial velocity of gas given ahigher conversion and rate of reaction at Ug=0.025 m/sec, at this velocity thereaction rate of monoethanolamine with carbon dioxide (94.1% conversion and RA= 7.75*10-3 Kmol/m3.sec) is higher than reaction rate of potassium carbonate withcarbon dioxide(29.3% conversion and RA = 2.73*10-3 Kmol/m3.sec). Furthermore,the addition of promoters to the 30%K2CO3 absorbents enhanced the reactionbetween potassium carbonate with carbon dioxide and increased the reaction ratewhen increasing the concentration of promoters to the critical concentration. Theresults show that the piperazine is a better promoter from other types of the aminoacid promoter used was 52.1% increase in carbonate conversion with carbondioxide.