Energy from citrus wastes in Belize : industry overview

The extraction process generates some 58,000 tons per year of solid wastes, and an unknown amount of liquid wastes. The waste management practices at Belizean citrus processing facilities consist primarily of open dumping of solid waste and untreated discharge of liquid wastes. These practices are costly and environmentally undesirable. The managers of two of the processing facilities have been trying to identify available, environmentally benign, and cost-effective waste management technologies applicable to their specific sites for years. Production of cattle feed and other byproducts, the conventional method of processing solid citrus wastes, has proven uneconomical in Belize. The objective of this study was to identify options for converting citrus waste in Belize into usable forms of energy. Five such options have been identified: (1) proper landfilling of solid wastes; (2) cattle feed plus byproduct recovery; (3) cattle feed plus anaerobic digestion; (4) anaerobic digestion of all solid and liquid wastes; and (5) combustion of solid wastes and anaerobic digestion of liquid wastes. Each of the options addresses the environmental problems, and in the last three options, capital and operating costs would be offset by the savings resulting from displaced fossil fuels. The last option represents the maximum potential generation of usable energy from citrus wastes. Suggestions are made for site-specific feasibility and cost studies. (Author abstract, modified)