Energy & Fuels, Vol.32, No.3, 3469-3476, 2018
Impact of Torrefaction on the Fuel Properties and Combustion Characteristics of Compost of Food Waste and Sawdust
With rapid global development, the amount of food waste is increasing, which has seriously affected the environment. Usually, food waste is composted with sawdust to prevent environmental pollution as a result of the loss of N and S. Unfortunately, the quality of the compost of food waste and sawdust (CFS) is poor, and the material is hard to handle. Torrefaction, a process of slow pyrolysis under anoxic conditions, can be used to improve the properties of a fuel sample. This study investigated the fuel properties of CFS samples subjected to torrefaction at five different temperatures (250, 300, 350, 400, and 450 degrees C) and a residence time of 30 min. Physicochemical analyses of the samples were carried out according to standard methods, and the combustion characteristics of the samples were studied by thermogravimetric analysis. Torrefaction has great impact on proximate and ultimate analyses, chlorine contents, energy and mass yields, and grindability and combustion characteristics. The grindability and combustion properties of CFS were also improved by torrefaction. At a torrefaction temperature (300 degrees C), the higher heating value reached its maximum value (19 334 kJ/kg), meaning that the torrefied CFS contained up to 63.89% of its original energy content and the combustion characteristics were optimal at this torrefaction temperature.