Improving Sustainable Energy in Mexico: Biodigester Mixing System

Abstract

Final report and team photo for Project 22 of ME450, Winter 2009 semester.Biodigesters are an emerging technology used in Mexican state of Michoacán to produce sustainable energy from waste. A biodigester converts animal and plant waste into biogas, which contains 50% to 60% methane. This biogas is then burned in the home instead of wood, which burns dirty and creates noxious fumes inside the home. Burning biogas can also offset carbon emissions since it produces less CO2 per energy unit than wood. These biodigestion systems, however, have some issues that must be addressed. To aid in the digestion, the biomass must be mixed occasionally; current methods are external and rather crude. This project sets out to design and prototype a mixing system that will locally suspend inorganic solids that collect on the bottom of the digester. This suspension will increase the likelihood of the solids leaving the digester during the natural plug-flow of the system. The more solids removed results in longer time needed for them to build up, thus increasing the maintenance time of the biodigester. Along with increasing maintenance time, mixing may increase biogas production.Sherri Cook (BLUElab, U of M)http://deepblue.lib.umich.edu/bitstream/2027.42/62475/2/ME450 Winter2009 Team Photo - Project 22 - Biodigester Mixing System.JPGhttp://deepblue.lib.umich.edu/bitstream/2027.42/62475/1/ME450 Winter2009 Final Report - Project 22 - Biodigester Mixing System.pd