Anaerobic digestion of solid waste: a new approach to accommodating feedstock variability to achieve stable operation at an affordable cost

加拿大人每年处理约2500万吨固体废物，其中包括800万吨有机废物，这些废物在垃圾填埋场分解后产生渗滤液和垃圾填埋气体，两者都对环境构成潜在威胁。有机废物可以进行好氧堆肥或厌氧消化，但这些过程很昂贵，部分原因是所有废物都是异质的，含有不可处理的外来物质。厌氧消化在欧洲很受欢迎，因为那里的法规要求废物管理成本很高，而在北美很少见，因为那里的法规不那么严格，处理成本也较低。

Canadians dispose of about 25,000,000 tonnes per year of solid waste, including 8,000,000 tonnes of organic waste which decomposes in landfills to produce leachate and landfill gas, both a potential threat to the environment. Organic waste can be aerobically composted or anaerobically digested but the processes are expensive partly because all waste is heterogeneous and contains un-processable foreign matter. Anaerobic digestion is popular in Europe where waste management costs are high because of regulations, and rare in North America where regulations are less stringent and disposal costs are lower. A new approach to anaerobic digestion has been designed and patented specifically to be versatile, robust and affordable in North America. Its novelty is based upon the concept of digesting the mixed waste as-received, in a two-stage reactor, with very little pre-processing. This dramatically reduces complexity and cost in exchange for longer digestion times. The process stabilizes the waste and produces renewable energy in the form of biogas. The process is licensed to Miller Waste Systems Inc., a Canadian leader in waste diversion and organic waste processing. The purpose of this research and development grant, in collaboration with Miller Waste Systems Inc., is to assess the performance of the process on the kind of mixed and variable wastes which are representative of what is actually generated in the marketplace (municipal, industrial commercial and institutional), with the ultimate aim of dramatically reducing the amount of organic waste going to landfill.