Solid fuel recovered from food waste dechlorination: Proof of concept and cost analysis

Chlorine content is one of the key performance metrics for solid-recovered fuel. In this study, food waste, wood waste, and plastics were collected from municipal solid waste to prepare solid-recovered fuel, which was then used to evaluate several parameters in the dechlorination process. Approximately 87-93% of the chlorine content of the raw materials was effectively removed using calcium hydroxide as a detergent under a range of liquid-to-solid ratios and washing times during the pretreatment phase. Using calcium hydroxide was beneficial for increasing the high heating value, whereas elution with deionized water was beneficial for ash removal. The high heating value of the dechlorinated solid-recovered fuel was 4.54% higher than that of the untreated solid-recovered fuel, and the highest high heating value achieved was 25.55 MJ/kg. The dechlorination process increased the mass yield by 1.34% and the energy yield by 1.64%. To produce, store, and transport solid-recovered fuel on a large scale, the capital and manufacturing costs were calculated to be US$2.4/t and US $281.3/t, respectively, and the total cost could be reduced substantially by minimizing the transportation cost. The dechlorination technologies investigated in this study provide guidance for producing high-standard solid-recovered fuel at a lower cost and with less chlorine pollution compared with the currently used processes.