NOVELTY - Integrated device, comprises: a gasifier (102) configured to produce a gaseous compound from a biomass, comprising an input (104) for biomass, an inlet for an oxidizing agent and an outlet of the gaseous compound containing carbon monoxide; means (110) for methanation of carbon monoxide to produce substitute natural gas from the gaseous compound leaving the gasifier; means (114) for methanation of carbon dioxide to produce substitute natural gas; and a means (118) for producing hydrogen gas from water and electrical power.    USE - The integrated device is useful for producing substitute natural gas (claimed).    ADVANTAGE - The integrated device iincreases the yield of substitute natural gas; and provides solids that can be recycled, thus increasing combustion means of performance.    DETAILED DESCRIPTION - Integrated device, comprises: a gasifier (102) configured to produce a gaseous compound from a biomass, comprising an input (104) for biomass, an inlet for an oxidizing agent and an outlet of the gaseous compound containing carbon monoxide; means (110) for methanation of carbon monoxide to produce substitute natural gas from the gaseous compound leaving the gasifier, where the means comprises at least one inlet for the water and an inlet for the gaseous compound from the gasifier; means (114) for methanation of carbon dioxide to produce substitute natural gas comprising at least one inlet for water and an inlet for carbon dioxide from the means for methanation of carbon monoxide; and a means (118) for producing hydrogen gas from water and electrical power comprising a power supply, an inlet for water and an outlet for supplying the hydrogen gas through methanation of carbon dioxide. INDEPENDENT CLAIMS are also included for:    (1) network, comprising at least one device; and    (2) producing substitute natural gas, comprising: a gasification step for generating a gaseous compound from a biomass; methanation of carbon monoxide to produce substitute natural gas from the gaseous compound derived from the gasification step; methanation of carbon monoxide with at least an input stage for water and for the gaseous compound derived from the gasifier; and methanation of carbon dioxide to produce substitute natural gas comprising at least one input stage for water and an inlet for carbon dioxide from the methanation of carbon monoxide, and a means for producing hydrogen gas from water and electric current comprising a step of power supply, a step for water inlet and a step for output for dihydrogen used during the step of carbon dioxide methanation.    DESCRIPTION OF DRAWING(S) - The figure shows an integrated device.    Gasifier (102)    Input for biomass (104)    Means for methanation of carbon monoxide (110)    Means for methanation of carbon dioxide (114)    Means for producing hydrogen gas (118)