Compost of Biodegradable Municipal Solid Waste as a Fuel in Lignite Co-combustion

Abstract

In Greece, 5.8 million tons of municipal solid wastes (MSW) are produced annually, of which 2.47 million tons are bio-wastes. Composting is an alternative treatment of bio-wastes instead of landfill.  Τwo composting plants operate in Greece, one in Ano Liossia (capacity 1,200 tons/day, producing 120 tpd compost) and another in Chania (capacity 70,000 tons/year, producing 20,000 tpa compost). In addition, since 2018, the first integrated waste management plant was set off in the region of Kozani (capacity 120,000 tons/year). An alternative utilization of the compost, produced in the latter plant, was investigated in this study. In particular, instead of using compost as fertilizer, the energy recovery from this bio-waste was attested. Utilization of compost of MSW for energy production purposes has rarely been studied in the literature. Several blends of compost with lignite were prepared and their energetic potential was determined. Proximate analyses and gross calorific value (GCV) determination were conducted. Wastes and biomass-based fuels differ in many ways from fossil fuels. The CLOF sample revealed the highest GCV and the lowest ash content than all analyzed samples. Based on all analytical determinations, compost and its mixtures with lignite could be regarded suitable for energy recovery by thermal processes, such us combustion. Further studies should be done including emission analysis, ash deposition during combustion (corrosion, slagging and fouling).