Utilization of CO2 as carbon source for preparation of sandy Al(OH)3 in concentrated KAl(OH)4 solutions: a kinetic study. Issue 20 (18th October 2019) - Liu, Cheng-Lin
ABSTRACT: The emission of CO2 have led to the vital climate change commonly referred to global warming. Carbonation decomposition of potassium aluminate solutions is adopted for carbon capture and production of Al(OH)3 in this study. The influence of temperature in the range from 60°C to 90°C, caustic concentration in the range from 220 K2 O L −1 to 280 g K2 O L −1 and CO2 concentration in the range from 10% to 50% on the precipitation ratio and crystal size distribution of Al(OH)3 was investigated. The results indicated that the carbonation process of potassium aluminate can be divided into three periods, and the carbonation time decreased with the increase of the reaction temperature and CO2 concentration or reduction of the caustic concentration. The kinetic model of carbonation decomposition of potassium aluminate solution is established based on the experimental results. By the comprehensive analysis above, the apparent activation energy is 59.35 kJ mol −1, demonstrating that the carbonation decomposition of potassium aluminate solution is easier than that of sodium aluminate solution.