Characteristics of Fry-Drying and Solid Refuse Fuels for Organic Wastes with High Water Content

With the dramatic increase in the quantity of organic wastes, economic and environmentally friendly technologies are urgently required for reducing the volume of sludge and remediating its harmful impacts. In this study, drying experiments were performed on sludge through fry-drying technology and the characteristics of the resulting fuels were investigated to identify proper methods for treating sewage sludge, wastewater sludge, swine excreta, and food waste and converting them into fuels. The four types of organic wastes were fry-dried, and the best drying conditions were found to be 140 °C for 8 min for sewage sludge and 150 °C for 10 min for wastewater sludge, swine excreta, and food waste. The water contents of sewage sludge, wastewater sludge, swine excreta, and food waste were 2.40 wt%, 2.70 wt%, 2.90 wt% and 5.82 wt%, respectively. Based on the results of fuel ratio, C/H ratio, thermogravimetric analysis (TGA), and derivative thermogravimetric (DTG) analysis on the four types of fry-dried solid refuse fuels, mixing the waste fuels with a certain proportion of coal for incineration in order to control the early ignition and rapid incineration rate was found to be effective.