Waste-to-hydrogen: Recycling HCl to produce H2 and Cl2

Coal-fired power plants are the most common form of power generation in many regions, which continuously produce waste heat and hydrogen chloride (HCl) flue gas. To address this issue, a novel Cu-Cl hydrogen production cycle is modeled to recycle industrial waste heat and exhaust HCl and to produce hydrogen, realizing the waste-to-hydrogen (WtH) process. To complement the process analysis, a gate-to-gate life cycle emission analysis and gate-to-grave cost-benefit analysis have been performed to evaluate the commercial feasibility and environmental impacts. The final results of the product cost and life cycle CO2 emission of this Cu-Cl cycle are 2.8 US dollars/kg H-2 and 8.7 kg CO2/kg H-2, respectively. Cu-Cl cycle offers an economically competitive option compared with the steam methane reforming (SMR) hydrogen production process if taking the benefit of Cl-2 into account. The life cycle CO2 emission of the Cu-Cl cycle is less than other existing processes, as the process can consume a considerable amount of HCl gas, which is regarded as greenhouse gas as well. The proposed process is shown to be a promising alternative to conventional hydrogen production processes.