Chemical looping with CCUS

Chemical looping combustion (CLC) is a process for generating energy from fossil fuels while capturing carbon dioxide (CO2) emissions. Unlike traditional combustion, which burns fossil fuels in the presence of air, CLC uses metal oxides as oxygen carriers to provide oxygen for combustion while also capturing and separating CO2 from the flue gas. Fluidised bed chemical looping is a process in which two reactors work in parallel to generate hydrogen and a high-purity CO2 stream. In the first reactor, an oxygen carrier (metal oxide) is oxidised with steam, thus producing H2. The oxidised oxygen carrier is sent to the second reactor, where it is brought into contact with a fuel. The fuel is oxidised generating CO2 while reducing the oxygen carrier, which is sent back to the first reactor, working in a loop. In the fixed-bed chemical looping hydrogen process, the oxygen carrier is not physically circulated. Instead, the oxidation and reduction steps take place alternately in the same fixed-bed reactor, which allows for easy operation without moving parts and high hydrogen purity. The asynchronous use of multiple reactors enables continuous hydrogen production and recovery of heat from exothermic oxidation for endothermic reduction, which increases the overall efficiency of the process.