Pyrolysis-combustion of rural solid waste: Self-sustaining operation and pollutants emission.

• Required energy for pyrolyzing RSW in different moisture contents was evaluated. • An ERPC index was developed to evaluate the energy and mass flows. • Optimal parameters were proposed to achieve a self-sustaining pyrolysis. • RSW Pyrolysis was analyzed from aspects of energy, pollutants and carbon footprint. Rural solid waste (RSW) is a serious problem which not only causes environmental pollution, but also limits the development of rural areas. Pyrolysis is an alternative since it can efficiently reduce RSW, meanwhile, the treatment capacity is matched for RSW production. However, conventional pyrolysis of RSW faces two important issues: energy cost and pollutant emission. Therefore, in this work, food waste (FW) was taken as the representative of high-moisture and low-heating-value organic waste in RSW, the energy required for pyrolysis, and the heat produced by combusting pyrolytic products were investigated. Based on calculating the Energy Ratio of Production to Consumption (ERPC) index, the self-sustaining pyrolysis-combustion conditions were established, and the carbon footprints in various scenarios were discussed. Additionally, waste paper, plastic, fabric and poplar scraps were selected as the representative organic wastes (OW) in RSW. The pyrolytic behaviors and pollutant emission (NO x and SO 2) of individuals and blended OW were investigated. Compared to direct combustion of OW, the NO x and SO 2 emissions can be reduced by 86 % and 100 %, respectively, during pyrolysis-combustion process. Combined the above aspects, it is proved pyrolysis-combustion can be a feasible approach to treat RSW, due to it can be operated without extra energy supply, and also shows obvious environmental benefits compared to direct combustion technology. [ABSTRACT FROM AUTHOR]