BIOGAS PRODUCTION FROM AUTOCLAVED AND ROTARY DRUM REACTOR-TREATED MUNICIPAL SOLID WASTES

摘要

The rotary drum (RDR) process and the autoclave process have been used to pre-treat MSW and separate the biodegradable fraction. The present study compares the characteristics of biodegradable materials derived from MSW using the above mentioned processes, it examines the potential for biogas production and also compares the technological and economical performances of these different MSW pre-processing technologies. Raw MSW has been pre-processed with either the RDR or the autoclave process, followed by trommel screening. Samples of the pre-treated MSW have been collected and tested for biogass production under mesophilic (35℃) and thermophilic (50℃) anaerobic conditions. The cumulative methane yields for DRD pre-treated MSW, after 13 days mesophilic or thermophilic conditions, were measured as 334 and 362 mL [CH4]/g [VS added], respectively, while the respect values for the autoclave pre-treated MSW were 289 and 301 mL [CH4]/g [VS added]. In all cases, the methane content of biogas was between 56.1-60.6%. Other chemical and physicochemical characteristics of both feedstocks were found to have remarkably similar characteristics, despite the different nature of treatment and the fact that the feedstocks derived from different MSW. Market search indicated that the RDR process requires less capital and less energy (10-13 million US$ for a 100,000ton MSW/yr; 70-110 kWh/ton MSW), compared to the autoclave process (16-20 million US$ for a 100,000ton MSW/yr; about 325 kWh/ton MSW). MSW pre-processed with either RDR or autoclave process is an excellent feedstock for biogass production. The RDR process appears to have lower capital cost and requires less energy to operate than the autoclave process for treating the same amount of MSW. However, the autoclave process requires less space and is more physically stable.