Process design and development for improving the quality of by-product sulfuric acid for its reuse in chlorine drying

ERCO Worldwide在萨斯喀彻温省经营一家氯碱生产工厂。该工厂每年生产并销售约35000吨氯。该工厂在氯干燥操作中使用98%的硫酸作为原料。在干燥过程中，硫酸的浓度从98%下降到93%。因此，每年从氯干燥过程中产生3267吨93%的硫酸作为副产品。目前，ERCO Worldwide将93%硫酸卖回给98%硫酸的供应商。在硫酸工业中，93%的强酸被认为是超标酸，因此不容易上市。因此，ERCO Worldwide以折扣价出售93%的酸。

ERCO Worldwide operates a Chloralkali production facility in Saskatchewan. In this facility, about 35,000 MT of chlorine is produced per year and marketed. The plant uses 98% sulphuric acid as a raw material in the chlorine drying operation. In the drying process, the concentration of sulphuric acid decreases from 98% to 93%. As a result, 3267 MT of 93% sulphuric acid is produced as a by-product per year from chlorine drying process. At present, ERCO Worldwide sells the 93% Sulphuric acid back to the supplier of the 98% acid. In the sulphuric acid industry, 93% strength acid is considered as off specification acid and therefore, cannot be easily marketed. Therefore, ERCO Worldwide sells the 93% acid at a discounted price. Dr. Ajay Dalai at the department of Chemical and Biological Engineering at the University of Saskatchewan specializes in green technologies and the production of adsorbents for water removal. ERCO Worldwide is interested in collaborating with Dr. Ajay Dalai to develop a process technology to convert 93% acid to 98% strength and reuse it in the chlorine drying operation. This will be a significant improvement to the existing operation, reduce costs related to handling and shipping to supplier of the acid. The estimated annual savings to ERCO Worldwide would be approximately $500,000. The work will be done in two phases. In phase 1, literature survey will be completed to understand the current developments, and carry out a process review using a simulation software. In phase 2, experimental work will be done to determine, if suitable adsorbents can be used to remove water from 93% acid and to upgrade it to 98% strength.