Production of Blue and Green Hydrogen by Chemical Looping Reforming of Methane and Biogas Using a Highly Reactive Cu-Based Oxygen Carrier

Blue hydrogen and green hydrogen are key sustainable solutions to decarbonize European economy in the coming decades in order to achieve climate neutrality by 2050. The objective of this work was to assess the suitability of a synthetic Cu-based oxygen carrier in a continuous pilot plant for the production of blue and green hydrogen through the autothermal Chemical Looping Reforming (CLRa). In CLRa, methane is converted to a H2 +CO mixture through partial oxidation and reforming reactions in the fuel reactor. The degree of the partial oxidation of methane was defined by controlling the oxygen flow in the air reactor. Steam was used as reforming gas in natural gas to produce blue H2 , but the existing CO2 in biogas was the reforming gas to produce green H2 . Operating at 950 ºC in the fuel and air reactors, CH4 conversion and H2 yield parameters were 96% and 2.60 moles of H2 per mole of CH4 , respectively. These experimental results were close to the theoretical values that could be achieved in the CLRa process. Furthermore, the physicochemical characterization of the samples extracted from the pilot plant throughout the experimental campaign revealed that the Cu-based oxygen carrier maintained its mechanical integrity and chemical stability under harsh operating conditions. Therefore, it can be concluded that Cu-based oxygen carriers can be considered a promising alternative to Ni-based materials for the production of blue and green hydrogen through the CLRa process