Fundamental Research On The Phase Equilibrium Of Strengthen Carbonation Reaction System

Owing to the large number of CO₂emission in the world, development ofa low cost and low environmental risk technical system for CO₂mitigation isnot only the impending science and technology needs for reducing CO₂emission in China, but also the frontier science and technology of CO₂emission control technology all over the word. Using calcium/magnesiumcontained solid residua as raw materials; CO₂can be sequestrated by indirectmineral carbonation. It can be realized that not only the CO₂can be processedon-site into a solid, but also the solid residua can be utilized as resources,which has important significance on the development of circular economy inChina. Currently, the process of indirect CO₂mineral sequestration withsteel-making slag and carbonate production has a wide application prospect,but lack of theoretical data. The purpose of this paper is to solve theseproblems and the following studies have been done.（1） In strengthen carbonation reaction system, large number of acetic aciddistribution coefficients were measured, the ionic activity coefficient model ofthe main component and the crystallization conversion rate model ofcarbonation reaction was established. （2） According to the considerably related literature reports, the preciseconstant volume method was selected to calculate the CO₂solubility in thehigh-pressure multiphase gas-liquid equilibrium system. A set of preciseexperimental apparatus was builded to measure gas solubility data in thehigh-pressure multiphase gas-liquid equilibrium system and the experimentaldevice was proved to be reliable. The average deviation of the experimentaldevice is1.62%and it is enough to meet the experimental demands.（3） A detailed study on dissolution behavior of CO₂in tributyl-phosphatesolvent and a preliminary study on the solubility of CO₂in solution containingcalcium were implemented. The solubility of CO₂in tributyl phosphate （TBP）solvent was measured in a temperature range of303.15K-363.15K and gaspressure of CO₂up to4.5MPa. Results showed that the solubility of CO₂inTBP solvent increased with the augment of CO₂gas pressure and decreasedwith the growth of equilibrium temperature. GC/MS and FT-IR analysis resultindicated that the capture process by TBP solvent could be regarded asphysical absorption. The Henry coefficient which was obtained by fitting theexperimental data was well consistent with the Henry’s law.