Development of gasification/combustion characteristics at thermo-chemical conversion of biomass mixtures

To promote more effective utilization of wheat straw for cleaner heat energy production with reduced greenhouse carbon and polluting emissions, experimental study and mathematical modelling of the processes of wheat straw co-combustion with wood and peat pellets are carried out with the aim to assess the impact of the mixture composition on the development of the main gasification/combustion characteristics and heat energy production. The processes of thermal decomposition of wheat straw mixtures and combustion of volatiles were studied experimentally by varying the mass load of wheat straw pellets in the mixtures. The development of the main gasification/combustion characteristics was studied experimentally using a batch-size pilot setup with a heat output up to 2 kW, which combines a biomass gasifier and a combustor. The results of the experimental study and mathematical modelling suggest that creating a mixture of fuels, which have different elemental compositions and heating values of the components, makes it possible to control the thermal decomposition of wheat straw by varying the mass flow of volatiles entering the combustor and so improving the combustion conditions in the flame reaction zone, which results in faster ignition with more complete combustion of the volatile compounds and in cleaner heat energy production.