Fuel gas production from biomass, especially wood used in engines comprises use of a solid bed gasifier

摘要

Production of a fuel gas from biomass, especially wood used in engines, comprises the use of a solid bed gasifier. Production of a fuel gas from biomass, especially wood, comprises reacting the biomass with an inorganic mixed catalyst; conditioning the doped biomass inside and outside of the reactor to give a residual water content of 18-32 wt.% and preheating to temperatures up to 120 deg C; heating in the upper part of the reactor with hot vapor and/or other hot media to 125-195 deg C and adjusting the water content to 18-32 wt.%; further heating the biomass either with the hot gas media to 250-480 deg C or feeding a part of the crude gas removed in the lower part of the reactor to the upper part of the reactor and heating the biomass to 250-580 deg C; heating the biomass remaining as coke in the lower part of the reactor to at least 900 deg C by adding 5-25 vol.% hot air; and purifying the part of the crude gas removed in the reactor to fuel gas. An Independent claim is also included for a solid bed gasifier for producing fuel gas from biomass comprising a material feed (2), hot vapor nozzles (3) in the upper part, lower hot air nozzles (5) in the central part, a gas outlet in the central part, and an ash collector (8) and outlet in the lowest part and optionally further hot air nozzles (7) in the lower part between the gas outlet and ash outlet. Preferred Features: The doped biomass is heated to 150-180 deg C in the upper part of the reactor by adding super heated water vapor and adjusting the water content to 22-28 wt.%.