Method for producing automotive biological hydrogen-alkane gas from urban and rural organic waste through fermentation and purification as well as refinement

The invention relates to a technique for utilizing biomass waste, and aims at providing a method for producing an automotive biological hydrogen-alkane gas from urban and rural organic waste through fermentation and purification as well as refinement. The method comprises the following steps of collecting and storing a mixed gas which is formed by fermenting the urban and rural organic waste, pressurizing the mixed gas, and then carrying out desulfurization on the pressurized mixed gas, cooling the desulfurized mixed gas, and then pressurizing the cooled mixed gas, afterwards, carrying out dehydration and decarburization on the pressurized mixed gas, and subsequently, cooling, compressing and dehydrating the dehydrated and decarburized mixed gas, so as to obtain the automotive biological hydrogen-alkane gas of which the total concentration of H2 and CH4 is higher than 95%. According to the method, the desulfuration, the dehydration, the decarburization and the refinement are carried out aiming at the mixed gas prepared from the urban and rural organic waste through the fermentation, and the automotive biological hydrogen-alkane gas of which the total concentration of the H2 and the CH4 is higher than 95% can be obtained; the concentration of H2S is lower than 15mg/m ; high calorific power is more than 31.415MJ/m ; the national standard of an automotive compressed natural gas is reached; the automotive biological hydrogen-alkane gas can replace a petrochemical natural gas to be applied to a natural-gas automobile, and has an obvious economic environment and a social benefit.