CaBr2 hydrolysis for HBr production using a direct sparging contactor

We investigated a novel, continuous hybrid cycle for hydrogen production employing both heat and electricity. Calcium bromide (CaBr2) hydrolysis, which is endothermic, generates hydrogen bromide (HBr), and this is electrolysed to produce hydrogen. CaBr2 hydrolysis at 1 050 K is endothermic with a 181.5 KJ/mol heat of reaction and the free energy change is positive at 99.6 kJ/mol. What makes this hydrolysis reaction attractive is both its rate and the fact that well over half the thermodynamic requirements for water-splitting free energy of ÄGT = 285.8 KJ/mol are supplied at this stage using heat rather than electricity.