Effect of Na2CO3 on Production of NaHCO3 Using Desulfurized Na2SO4 Waste

CO 2 is the primary greenhouse gas emitted through human activities which cause global warming. Many countries and international regulations aim to reduce CO 2 and encourage development of a net-zero society by 2050, thus, CCUS (carbon capture, utilization, and storage) can be considered as a key technology for achieving this goal. Among the many industrial processes, NaHCO 3 production is a representative CCUS technology which satisfies both CO 2 reduction and economic incentive. Recently, Na 2 SO 4 waste, containing 15% impurities (i.e., various heavy metals), produced as a by-product generated from desulfurized processes in steel industry has received a great deal of attention since landfilling has been the only way to treat it. Na 2 SO 4 could be a suitable source of NaHCO 3 production as CCUS; however, there are no commercial processes for production of NaHCO 3 using Na 2 SO 4 as the raw material, since it has low production efficiency compared to other Na + sources. This study evaluates the regeneration of NaHCO 3 using Na 2 SO 4 waste and our results show that a combination of Na 2 SO 4 waste and the addition of 20% Na 2 CO 3 can sharply increase the yield of NaHCO 3 with minimizing the consumption of expensive NH 3 since alkaline properties of Na 2 CO 3 . Graphical Abstract