Design Models for Anaerobic Batch Digesters Producing Biogas from Municipal Solid Waste

Abstract

Models for the design of anaerobic batch digesters producing biogas from municipal solid waste (MSW) in Port Harcourt metropolis, Nigeria have been formulated. Experimental and field data were used to determine relevant design parameters for the batch digesters, especially the bio-kinetic behavior of MSW. The research data were analyzed using material balance analysis. The anaerobic digester was then designed and simulated for fractional conversion values of 0.2 ≤ α ≤ 0.8 and percentage total solids (PTS) concentration of 10-30%, using Microsoft Visual Basic Version 6.0 computer program. The simulation results were interpreted with Microsoft Chart Editor. The evaluation of research results showed that an empirical optimum PTS concentration of 20% was best suited for the batch digester processing the MSW for biogas generation. At this level of PTS concentration, the MSW digestion was most effective in terms of digester sizing, time of digestion, volume of biogas produced and overall cost of the digester, for the same level of percent stabilization.