Willow biomass as a feedstock for gasification

A study concerns the balance of mass and energy in the process of gasification of willow chips (acquired in 5-year rotation), as well as in the process of combustion of the gasification product with flue gas heat recovery. Thermochemical conversion of willow biomass resulted in the production of raw gas with the calorific value of 4937 kJ/kg. The product of gasification comprised a mixture of gaseous compounds, tars and water vapour. The gaseous compounds determined in the study included: hydrogen (8.30%), carbon monoxide (27.51%), methane (1.51%), carbon dioxide (3.79%), nitrogen (55.87%) and small amounts of hydrocarbons C1-C3. The ultimate production output of willow fuel was equal to 91.5 kg of chips per hour and the power output achieved 315 kW. Raw gas produced from willow biomass, mixed with air, was burnt at a temperature exceeding 1000oC and the flue gas heat was recovered in a water boiler and distributed in the central heating system. The collected thermal energy accounted for over 79% of the chemical energy of the biomass at the start of the process