Conversion of KCl into KHSO₄ in a membrane reactor: long-term experiments

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• 作者：M. Tomaszewska ; A. Mientka
• 关键词：Membrane reactor ; Separation of HCl ; Production of KHSO₄
• 刊名：Desalination
• 出版年：2009
• 出版时间：15 September 2009
• 年：2009
• 卷：245
• 期：1-3
• 页码：647-656
• 全文大小：739 K

文摘

The studies of a conversion of KCl with H₂SO₄ into KHSO₄ were performed using a reactor associated with direct contact membrane distillation (DCMD). Polypropylene (PP) capillary membranes were used in the experiments. The feed comprised of solutions containing 1 mol of KCl with various initial concentrations of H₂SO₄, equal to 1, 1.25 and 2 moles. The feed temperature at the inlet of the module amounted to 343 K and permeate 293 K. The reaction mixture was concentrated close to the saturated state, when crystals of KHSO₄ were precipitated from the solution after cooling. The mother liquor after separation of the precipitate was again concentrated by membrane distillation (MD). At DCMD operation conditions the transfer of water vapour and hydrogen chloride from the reaction mixture through the pores of hydrophobic membranes took place, whereas the non-volatile components were totally retained and continuously concentrated in the feed. It was found that amounts of hydrochloric acid in the permeate as well as amounts of KHSO₄ salt precipitated from the reaction mixture increased with a rise in the sulphuric acid concentration in the feed.