ANAEROBIC BIOCONVERSION OF MUNICIPAL SOLID-WASTES USING A NOVEL HIGH-SOLIDS REACTOR DESIGN - MAXIMUM ORGANIC LOADING RATE AND COMPARISON WITH LOW-SOLIDS REACTOR SYSTEMS

Novel, laboratory-scale, high-solids reactors operated under mesophili c conditions were used to study the anaerobic fermentation of processe d municipal solid waste (MSW) to methane. Product gas rate data were d etermined for organic loading rates ranging from 2.99-18.46 g of volat ile solids (VS) per liter (L) per day (d). The data represent the anae robic fermentation at high-solids levels within the reactor of 21-32%, while feeding a refuse-derived fuel (RDF)/MSW feedstock supplemented with a vitamin/mineral/nutrient solution. The average biogas yield was 0.59 L biogas/g VS added to the reactor system/d. The average methane composition of the biogas produced was 57.2%. The data indicate a lin ear relationship of increasing total biogas production with increasing organic loading rate to the process. The maximum organic loading rate obtainable with high-solids anaerobic digestion is in the range of 18 -20 g VS/L.d to obtain 80% or greater bioconversion for the RDF/MSW fe edstock. This loading rate is approximately four to six times greater than that which can be obtained with comparable low-solids anaerobic b ioreactor technology.