Food waste is one of the most prominent waste streams on the earth. The hotels, restaurants, fast-food joints and cafeterias had resulted in the generation of huge quantities of food wastes. The proportion of food waste in municipal waste stream is gradually increasing and hence a proper food waste management strategy needs to be devised to ensure its eco-friendly and sustainable disposal in the world.
Food waste is an untapped energy source that mostly ends up rotting in landfills, thereby releasing greenhouse gases into the atmosphere. Food waste includes organic wastes generated in hotels, restaurants, shopping malls and industrial parks in the form of leftover food, vegetable refuse, meat, teabags, napkins, milk products etc. It is difficult to recycle food waste since it contains high levels of sodium salt and moisture, and is mixed with other waste during collection.
The traditional food waste disposal: feeding pigs, crushing and discharging into sewers or direct landfill, composting and producing livestock feed. If the food waste is directly collected to feed the pigs, various germs in the food waste will be transmitted through the biological chain, and affecting human health. After simple treatment of food waste and discharge into the sewer pipe, it will easily cause water pollution and viruses. The cost of directly burying food waste is low, but it will occupy a lot of land, polluted water resources, and the discharged biogas will also cause more air pollution. Food waste composting is a relatively effective way of resource utilization, but due to the low quality of fertilizers and feeds, sales are poor.
At present, the more effective treatment method for food waste is fermenting biogas and refining biodiesel, which not only has economic benefits but also prevents environmental pollution.
Siedon offers food waste disposal system for this process.
The disposal of food waste: firstly, the collected food waste is separated to solid and liquid through a food waste dehydrator. The solid phase material obtained by extrusion is performed grease separation, and then subjected to a transfatting reaction at an appropriate temperature, and washed to obtain biodiesel.
For the remaining materials after oil and fat separation, anaerobic fermentation can be obtained in a closed container to obtain biogas. The CO2 separated by DDR type zeolite membrane can be sold as industrial raw materials, and the high-concentration biogas can be used for gas/steam turbine for Power generation. The biogas residue obtained after anaerobic fermentation can be used for composting or direct landfill.