Investigation of hydrogen production performance of various salts with chlor–alkali method

Three important products, namely chlorine gas, caustic soda, and hydrogen gas, are obtained with a Chlor-alkali process generally. Therefore, a Chlor-alkali process powered by the electricity generated from any renewable sources is an important industrial application as it produces three important products without emitting carbon. According to the activity series of K, Na, and Ca metals, the most hydrogen production was obtained with the aqueous solution of KCl, while the least with the aqueous solution of CaCl_2 in a certain period. The increase in the operating temperature, cell voltage, and mass flow rate, which are the experimental parameters, also increased the hydrogen production rate. The most effective of these three parameters on the hydrogen production rate was the cell voltage, and the least effective was the mass flow rate. The minimum hydrogen production rate is 27.36 mL/h when the aqueous solution of CaCl_2 is used with a mass flow rate of 0.3 g/s and cell voltage of 2.5 V at the operating temperature of 25 °C with energy and exergy efficiencies of 10.81 % and 8.47 %, respectively. The maximum hydrogen production rate is 295.68 mL/h when KCl salt solution is used with a mass flow rate of 0.7 g/s and cell voltage of 3.5 V at the operating temperature of 60 °C with energy and exergy efficiencies of 23.78 % and 17.63 %, respectively.