Low-Temperature-Solid Combustion Technology of Biomass for Pollution Reduction: Potentials and Necessary Fundamentals

The high temperature of solid combustion in modern combustors leads to serious pollution in the combustion of biomass and solid wastes. The broad demands of relatively small-scale combustion of solid fuels and the imposition of increasingly strict emission limits require more economical methods for pollution reduction. Based on literature and our own work, low-temperature-solid combustion technology, which applies low temperature for solids but normal temperature for gas during combustion, was introduced in this paper. The potential of this technology in pollution reduction was analyzed, and necessary fundamentals for equipment design/operation were discussed. It showed that, for straws, more than 60% of deposit and particle emission can be reduced and 100% of ash can be recycled when the solid temperature is <600 °C. Fundamentals on rates of inorganic release, char oxidation, phase transformation in the condensed phase, and NOx/SOx release are necessary for better application of the technology.