Electrochemical Recovery of Chlorine and Hydrogen from Hydrogen Chloride By-Product Produced in the Petrochemical Industry

摘要

Simultaneous production of hydrogen as an energy carrier and chlorine as a valuable chemical from recycled hydrogen chloride was investigated employing a lab-scale membrane electrolysis setup. The effects of various process parameters including current density (1-4 kA m~(-2)), cell temperature (45°-75°C), flow rate of hydrochloric acid feed (200-500 mL min~(-1)), and concentration of acid (18-21 wt.%) on the cell voltage and chlorine current efficiency (ChCE) were studied. The Tagu-chi design of experiments (L_(16) array) was employed to design the minimum number of experiments necessary to fully study the process. A filter press type cell of 10 cm surface area comprising a DSA anode, an alloy of predominantly nickel cathode and Nafion 115 membrane, was used. It was observed that increasing anolyte flow rate, anolyte concentration, or cell temperature caused a decrease in cell voltage and an increase in ChCE, while increasing current density linearly increased cell voltage and decreased ChCE.