System for the neutral/negative co2 production of syngas from solid fuels with high hydrogen content for uses at high temperature

An autothermal method by means of concentric bubbling fluid double bed for the production of syngas by gasification with biomass steam, in the presence of a granular material, the autothermal method comprising the following steps:

• continuous gasification under stationary bed condition of said granular material in bubbling fluidisation regime of biomass with water vapour, at a temperature between 700 and 900° C. and pressure close to the atmospheric pressure, with thermochemical transformation of the fuel into raw syngas and char, said raw syngas comprising heavy hydrocarbons (tars) in the vapor state and any harmful compounds in traces, in a first reaction volume;
• combustion in bubbling fluidised bed with air of the char and of auxiliary fuel in a second reaction volume;
• wherein said second reaction volume is a vertical cylindrical volume with a cylindrical wall and said first reaction volume is an annular cylindrical volume external to said second reaction volume and separated from said second reaction volume by means of said cylindrical wall, said first reaction volume being in functional connection with said second reaction volume;
• transfer of said granular material from said first reaction volume to said second reaction volume and vice versa, through siphons maintained in a condition of incipient fluidisation with water vapour;
• said granular material acting as a thermal carrier between said first and second reaction volumes;
• transfer of heat from said first reaction volume to said second reaction volume and vice versa by means of conduction and irradiation through said cylindrical wall;
• separation from the raw syngas obtained in said step of gasification of the solid particulate matter entrained by hot filters and hot conditioning of the syngas;
• the hot conditioning comprising the following sub-steps:
• catalytic conversion in the presence of water vapour of the heavy hydrocarbons with an increase of the fraction of hydrogen and carbon monoxide in the final gaseous product;
• and
• elimination of any harmful compounds in traces.