System and method for processing an input fuel gas and steam to produce carbon dioxide and an output fuel gas

A system for processing an input fuel gas and steam to produce separate CO2 and output fuel gas streams, the system comprising:

• a decarboniser segment configured such that at least a solid sorbent reacts therein with the fuel gas and steam to remove carbon from the input fuel gas and to produce the output fuel gas stream in an exhaust gas from the decarboniser;
• a calciner segment configured such that the solid sorbent from the decarboniser segment reacts therein to release the carbon as CO2 into the CO2 gas stream;
• wherein the system is configured such that CO2 partial pressures and temperatures in the decarboniser and calciner segments respectively are controlled such that the temperature in the decarboniser segment is higher than the temperature in the calciner segment such that heat is provided from the decarboniser to the calciner.