Calcium carbonate synthesis from waste concrete for carbon dioxide capture: From laboratory to pilot scale

Abstract

This research article explains the synthesis and scale-up of calcium carbonate (CaCO3) from waste concrete as calcium-rich material by an inorganic carbonation process. The operating parameters include S/L ratio, HCl concentration, contact time, and extraction pH were investigated. The calcium hydroxide (Ca(OH)2) was synthesized by reaction between calcium chloride (CaCl2) and sodium hydroxide (NaOH), which induced the spontaneous reaction of CaCO3 without additional energy consumption. The productivity of CaCO3 was 1 kg/d in the laboratory scale experiment, and the CaCO3 productivity was scale-up to 20 kg/d through pilot scale process by same way as the laboratory scale. The approximately 4800 g of CaCO3 was produced and 2112 g of CO2 was captured per each cycle operation. Consequently, considered power consumption, the estimated amount of reduced CO2 was 465 g of CO2 in the pilot-scale reactor per cycle and produced CaCO3 with a purity of 99.0 %.