Valorization of calcium carbonate-based solid wastes for the treatment of hydrogen sulfide in a semi-continuous reactor: Part II – Slurry bubble column pilot

Abstract

This work is devoted to the removal of H2S from the gas phase using a suspension of calcium carbonate-based residues, recovered from the production of sodium bicarbonate. A 145 L (1.6 m height and 0.34 m internal diameter) slurry bubble column (SBC) reactor was used. The gaseous effluent was bed from the bottom and get out from the top of the column. The suspension (2–20 wt%) was recirculated from the bottom to the top by a pump. This created a counter-current regime between the gas phase (from the bottom to the top) and the liquid phase (from the top to the bottom) which favor the gas/liquid exchange inside the reactor. The influence of different parameters including solid concentration in the suspension (ws), recirculating rate of the suspension (QR), inlet gas flow rate (QG), and volume of the suspension, was investigated. The results obtained with this confirmed those at the lab scale, for both synthetic gaseous effluent (H2S diluted in compressed air) and real gaseous effluent emitted by the buffer tank of a wastewater treatment plant. This allows validating the technology before its deployment at the large industrial scale for H2S removal from the gas phase.