Novel pulp mill wastewater recovery process for CO2 and SOx utilization

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Pulping industry has a pulp mill process that emits a significant amount of carbon dioxide (CO 2 ) and sulfur oxides (SO x ). The pulp mill wastewater has a high potential for reducing pollution caused by CO 2 and SO x because it contains useful mineral ions in high concentrations, such as Ca 2+ , Mg 2+ , Na + , and K + that react with carbonate and sulfate ions. In this study, we develop a novel pulp mill wastewater recovery process for CO 2 and SO x utilization. To design the CO 2 and SO x capture and utilization process using pulp mill wastewater, a process model is developed based on validated experimental data. The developed process model comprises the following three steps: (1) metal ion separation of pulp mill wastewater to produce KClO 4 , Mg(OH) 2 , and Ca(OH) 2 ; (2) SO x capture and utilization using Ca(OH) 2 and SO x , utilized as desulfurization gypsum; (3) CO 2 capture via generated KClO 4 , and the captured CO 2 is utilized as carbonate using Mg(OH) 2 and Ca(OH) 2 . Accordingly, the economic feasibility of the suggested process model is demonstrated by calculating the pay-back period in economic assessment. As a result, the desulfurization efficiency was 99% with high-purity gypsum production. In addition, ∼98.2% CO 2 was captured. Furthermore, the annual profit was increased by USD 94,469, and thus, the pay-back period was determined as 8.4 y. • Novel pulp mill wastewater recovery process developed for CO 2 and SO x utilization. • Challenges of the conventional CCS and desulfurization technology are addressed. • This is the first study to capture & utilize CO 2 and SO x using pulp mill wastewater. • Cost efficiency and environmental protection ensured.