Potential of Waste to Generate Heat at a Domestic Scale

Rising energy costs and net zero carbon goals mean that the UK needs plentiful and clean energy sources. Current clean energy sources (biomass/ heat pumps) in the country are insufficient to meet residential space heating demands. Further with the advent of higher energy costs, residents are expected to start burning more solid fuel in their homes, as opposed to using gas-based central heating. The UK generates 222.2 million tonnes of waste annually, of which only ~45% is recyclable. The typical calorific value of municipal solid waste and agricultural/garden waste is ~10 MJ/kg and ~20 MJ/kg respectively. Traditionally, waste to energy (WtE) for the circular economy has been associated with waste incineration, but it could be used for household heating. Efficient utilization of waste through different thermochemical transition pathways has been primarily explored at an incineration plant scale (~50 MW heat) and not at a scale of residential heating stove (~5 kW). In the present study, we will use thermogravimetric analyzer- mass spectrometer (TGA-MS) to simulate conditions inside a heating stove. Reaction parameters would include packed bed temperature of 650 °C and heating rate of 10 °C/min for characterisation and assessment of the volatile species evolved during the thermal degradation of several waste materials. Pyrolysis behaviour of some typical household wastes would be analysed through characteristic reaction temperatures and evaluation of mass loss rates. The results from this study can contribute to better evaluation and testing of different waste materials with the aim to know their technical and economic feasibility for heat generation at a small scale.