Recent advances of research in coal and biomass co-firing for electricity and heat generation

Coal-fired power generation resulted in a shortage of conventional fossil fuels and an increase in greenhouse gas emissions. The co-firing of coal and biomass waste in coal-fired boilers was a promising strategy to supplement the energy source and reduce greenhouse gases. However, the co-firing mechanism and potential problems were not well understood. Therefore, the differences between coal and biomass in properties such as proximate and ultimate composition, components in ash and the calorific value were first discussed. Next, compared with the combustion of coal alone, this review analyzed the discrepancies and corresponding issues of co-firing in combustion behaviors and products such as ash and gaseous pollutants. Finally, this review outlined how operational conditions could affect the co-firing performance.