NOVELTY - Washing (M1) hydrogen sulfide and carbon dioxide from a gas obtainable by gasification of a carbonaceous biomass, involves a) contacting the gas with a first absorbent solution comprising transition metal ions in acidic aqueous solution; b) binding hydrogen sulfide present in the gas to the first absorbent solution; c) recovering the gas; d) contacting the recovered gas with a second absorbent solution comprising an alkaline absorbent; e) binding carbon dioxide present in the recovered gas to the second absorbent solution; and f) recovering the gas obtained from step (e).    USE - For washing hydrogen sulfide and carbon dioxide from gas obtainable by gasification of carbonaceous biomass (claimed),and useful for producing hydrocarbons or its derivatives.    ADVANTAGE - The method recovers the gas that contains less than 20 (preferably less than 1) ppb of hydrogen sulfide level; provides simplification, increase of the effectiveness and identification of possibilities for synergism of the overall biomass to liquid (BTL) process; allows separate recovery of hydrogen sulfide and carbon dioxide; and saves the energy consumption.    DETAILED DESCRIPTION - Washing (M1) hydrogen sulfide and carbon dioxide from a gas obtainable by gasification of a carbonaceous biomass, involves a) contacting the gas with a first absorbent solution comprising transition metal ions in acidic aqueous solution, where the transition metal ions include copper, zinc, iron, and/or cobalt; b) binding hydrogen sulfide present in the gas to the first absorbent solution; c) recovering the gas from step (b); d) contacting the recovered gas from step (c) with a second absorbent solution comprising an alkaline absorbent; e) binding carbon dioxide present in the recovered gas from step (c) to the second absorbent solution; and f) recovering the gas obtained from step (e). An INDEPENDENT CLAIM is included for producing (M2) hydrocarbons or its derivatives from a biomass raw material, involving gasifying the biomass raw material in the presence of oxygen to produce a gas comprising carbon monoxide, carbon dioxide, hydrogen, water and hydrocarbons; optionally conducting a tar reforming step; optionally removing tar components from the gas; optionally adjusting a hydrogen-to-carbon monoxide ratio; conducting the method (M1); converting in a synthesis reactor at least a part of the carbon monoxide and hydrogen contained in the gas into a product including a hydrocarbon composition or its derivatives; and recovering the hydrocarbon composition or its derivatives.