Environmental impact assessment of nuclear assisted hydrogen production via Cu–Cl thermochemical cycles

The variation of environmental impacts with the efficiency of a hydrogen plant and the thermal output of a nuclear plant are studied for nuclear-based hydrogen production using three-, four- and five-step Cu–Cl cycles for thermochemical water splitting (TWS). Results are presented, on the basis of 1 kg hydrogen production, for two impact categories: global warming potential (GWP) and acidification potential (AP). Environmental impacts are evaluated with several approaches. First, environmental effects are calculated by varying the thermal output ratio, which represents the thermal energy used in Cu–Cl cycle divided by the total thermal energy output of nuclear plant, from 0.1 to 1. The results show that GWP can be decreased from 3.32 to 0.346 kg CO2-eq for the five-step cycle. Second, the hydrogen plant efficiency is altered from 0.34 to 0.65 to examine the corresponding change in environmental impacts. Increasing the hydrogen plant efficiency to 0.65 decreases the GWP to 0.4 kg CO2-eq and the AP to 2.1 × 10−3 kg SO2-eq.