Method for extracting hydrogen from a gas that contains methane, especially natural gas, and system for carrying out said method

A method for extracting hydrogen from a gas that contains methane comprising:

• catalytically splitting hydrocarbons contained in the gas into hydrogen, carbon monoxide, and carbon dioxide in a reformer, by means of steam;
• performing catalytic conversion of the carbon monoxide that was formed to carbon dioxide and hydrogen in a subsequent conversion stage, with steam;
• removing the carbon dioxide after the step of catalytic conversion by means of a gas scrubber;
• subsequently separating the remaining gas stream into a product gas stream that consists of hydrogen, and a waste gas stream, in a pressure swing adsorption system;
• passing the entire waste gas stream to a combustion chamber of the reformer, together with a partial hydrogen stream that is branched off from the gas behind the gas scrubber, as a combustion gas that is extensively free of carbon, and
• burning the waste gas stream and said partial hydrogen stream in the reformer;
• wherein during the production of hydrogen in a steady-state operation the amount of the partial hydrogen stream is adjusted so that the partial hydrogen stream meets an energy demand of the reformer during common combustion with the waste gas stream.