Method and apparatus for generating a methane-containing substitute natural gas and related energy supply system

摘要

The invention relates to a method and an apparatus for generating a methane-containing substitute natural gas from a carbon oxide-containing input gas and also to an energy supply system equipped with such an apparatus. According to the invention, the input gas is subjected to a methanation reaction where a superstoichiometric hydrogen fraction is established in the reactant gas. The product gas of the methanation reaction is divided by gas separation into a methane-containing retentate gas, which yields the substitute natural gas, and a hydrogen-containing permeate gas. At least some of the permeate gas is returned to the input gas and admixed therein to form the reactant gas for the methanation reaction. The invention may be used, for example, for renewable energy supply systems with biomass valorization.

主权项

1. A method for generating a methane-containing substitute natural gas from a carbon oxide-containing input gas, comprising
subjecting the input gas to a methanation reaction and dividing a product gas obtained therefrom by gas separation into a methane-containing retentate gas, which yields the substitute natural gas, and a hydrogen-containing permeate gas, and returning at least some of the permeate gas to the input gas and admixing therein to form a corresponding reactant gas for the methanation reaction, wherein a superstoichiometric hydrogen fraction is established in the reactant gas for the methanation reaction at all stages of the methanation reaction, and wherein a stoichiometry factor of the reactant gas, which is defined as the ratio of the difference in the proportions of hydrogen and of carbon dioxide to the sum total of the carbon monoxide and carbon dioxide proportions, is maintained above three.