Studies on the utilization of post-distillation liquid from Solvay process to carbon dioxide capture and storage

In this work, a method of precipitated calcium carbonate production from the post-distillation liquid created in the Solvay process and waste carbon dioxide was proposed and investigated. Precipitation was carried out in a model solution of calcium chloride containing ammonia at various molar ratios in relation to Ca2+ ions, while gaseous carbon dioxide was supplied to the reactor as a pure gas or as a mixture with air. It was assumed that the reaction was completed when the pH of the reaction mixture reached the value of 7. To characterize precipitated calcium carbonate particles, its size and crystalline form were determined. It was possible to utilize above 80% of calcium ions from a model post-distillation liquid and above 80% of carbon dioxide from a mixed air-CO2 gas stream using the one-stage precipitation process since the conditions of precipitation were controlled. Calcium carbonate in vaterite form produced in this process can be also a valuable product.