TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The decarbonizer is configured such that: the steam reacts with carbon monoxide in the fuel gas, or produced from the fuel gas in the decarbonizer, to produce carbon dioxide for adsorption by the solid sorbent; or the steam reacts with hydrocarbons in the fuel gas to produce either or both of the carbon monoxide and the carbon dioxide. The system further comprises: heat exchanger unit for exchanging heat between the decarbonizer and calciner segments, where the heat provided from the decarbonizer to the calciners provided through the heat exchanging unit; combustor (203) for providing additional heat to the calciner segment; and feed for feeding the output gas stream into a distribution network, where the carbon dioxide gas stream is feed into a carbon dioxide gas distribution network, which is configured for delivery of the carbon dioxide gas stream for sequestration. The solid sorbent comprises lime particles, which is 20-200 mu and at the exhausts of the calciner and decarbonizer segments are 700-950 degrees C. The output fuel gas stream comprises hydrogen or methane. The input fuel gas comprises syngas (206), hydrogas, synthetic natural gas or natural gas (NG). The solid catalyst is: provided in the decarbonizer segment to activate a reaction to produce the output fuel gas in the exhaust gas from the decarbonizer; or supported in the decarbonizer segment, or mixed with the solid sorbent as separate particles, or incorporated into the solid sorbent, where the solid catalyst is mixed with the solid sorbent, and a particle size of the solid catalyst is larger than a particle size of the solid sorbent, where the particle size of the solid catalyst greater than or equal to 150 mu and the particle size of the solid sorbent is less than 125 mu . The solid catalyst comprises iron oxide. The methane gas distribution system comprises an existing NG distribution network, which comprises transportation of liquified gas and low pressure gas delivery. The gas distribution network is further configured for delivering the output fuel gas in the form of methane to a reactor configured for pre-combustion removal of carbon dioxide from the methane. The reactor configured for pre-combustion removal of carbon dioxide from the methane generates separate hydrogen and carbon dioxide streams from the methane. The carbon dioxide gas distribution network is configured for receiving an additional feed from the or an Endex reactor (200) configured for pre-combustion removal of carbon dioxide.