NOVELTY - Production of methane rich gas mixture for further application in high temperature fuel cells or for manufacturing synthetic natural gas (SNG) from gasification derived synthesis gas mixtures that contain compounds problematic to conventional methanation units, includes methanation, water gas shift reaction, and converting the problematic compounds to less problematic compounds, in a unit(s), e.g. by hydrodesulfurization of organic sulfur species. The unit is operated at 200-900 degrees C and 0.8-70 bars, and comprises a catalyst that contains metals, e.g. molybdenum.    USE - Process of producing methane rich gas mixture for further application in high temperature fuel cells or for manufacturing SNG from gasification derived synthesis gas mixtures that contain compounds problematic to conventional methanation units, such as organic sulfur or nitrogen compounds, alkanes, alkenes, alkynes, aromatic hydrocarbons e.g. naphthalene, toluene, benzene, phenols, or other non-aromatic hydrocarbons (claimed).    ADVANTAGE - The unfortunate temperature level sequence and the number of operation units of the process as well as the energetic losses can be avoided. A methane-rich stream can be produced from sulfur-containing feedstocks containing 10-95 mol.% methane.    DETAILED DESCRIPTION - Production of methane rich gas mixture for further application in high temperature fuel cells or for manufacturing SNG from gasification derived synthesis gas mixtures that contain compounds problematic to conventional methanation units, such as organic sulfur or nitrogen compounds, alkanes, alkenes, alkynes, aromatic hydrocarbons e.g. naphthalene, toluene, benzene, phenols, or other non-aromatic hydrocarbons, includes methanation, water gas shift reaction, and converting the problematic compounds to less problematic compounds, in a unit(s), e.g. by hydrodesulfurization of organic sulfur species; hydrodenitrogenation of organic nitrogen species; hydrogenation or reforming of alkanes, alkenes, or alkynes; or hydrogenation, reforming, or cracking of hydrocarbons. The unit is operated at 200-900 degrees C and 0.8-70 bars, and comprises a catalyst that contains metals, e.g. molybdenum, cobalt, ruthenium, nickel, wolfram, or their sulfides as active phase and is supported on materials containing e.g. aluminum, silicon, titanium, zirconium, gadolinium, manganese, vanadium, lanthanum, chromium, or their oxides. An INDEPENDENT CLAIM is included for a method of converting a raw gas into a methane-rich and/or hydrogen-rich gas comprising:    (A) providing the raw gas stemming from a coal and/or biomass gasification process, where the raw gas comprises besides methane and hydrogen content carbon-monoxide, carbon-dioxide, alkanes, alkenes, alkynes, tar, especially benzole and naphthalene, carbon oxysulfide (COS), hydrogen sulfide, and organic sulfur compounds, especially thiophenes, where the ratio of hydrogen to carbon monoxide is 0.2-5;    (B) bringing the raw gas into contact with a catalyst arranged as a fluidized bed reactor above 200 degrees C and at greater than or equal to 1 bar to convert the raw gas into first product gas, simultaneously converting organic sulfur components into hydrogen sulfide and reform tars, generating water/gas shift reaction, and generating methane from hydrogen/carbon monoxide content;    (C) bringing the first product gas into sulfur absorption process to generate a second product gas, reducing the content of hydrogen sulfide and COS from 100-1000 ppm down to less than or equal to 1000 ppb;    (D) optionally bringing the second product gas into a carbon dioxide removal process to generate a third product gas almost free of carbon dioxide;    (E) bringing the third product gas into second methanation process to generate fourth product gas having methane content above 5 vol.%;    (F) optionally bringing the fourth product gas into carbon dioxide removal process to generate a fifth product gas almost free of carbon dioxide; and    (G) bringing the fifth product gas into an hydrogen separation process to separate hydrogen rich gas from a remaining methane-rich gas, called substitute natural gas.