Energy yield potentials from the anaerobic digestion of common animal manure in Bangladesh

This study provides previously unavailable field data relating to the biogas and methane yields from supervised authentic anaerobic digesters using the most common animal manure in Bangladesh: cow dung, poultry litter and town cattle market straw which are found to produce biogas yields of 0.034, 0.030 and 0.142 m3/kg respectively, with methane concentrations of 60% and 62% and 74% respectively and total solids of 19, 23 and 45 respectively. It also reports indications that in unsupervised plant issues with underfeeding, improper water mixing and irregular feeding are very common – all of which can significantly reduce yields. The figures above should thus be treated as maximum, optimum field values. These results provide reliable data for use in scaling up for national energy and investment planning, as they related directly to common scenarios of family smallholdings, common sized poultry farms and town cattle markets in Bangladesh where there is a reliance on combustion of local wood and dung biomass for cooking, creating air pollution, health and environmental degradation issues

Multifaceted approach for characterization of solid residues from sludge incineration

The Italian Water Research Institute (IRSA) carried out sludge incineration tests on a demonstrative plant equipped with a circulating fluidized bed furnace. Aim of this paper is to present the potential applicability of non-conventional techniques for solid residues characterization. Results of five tests performed under different operating conditions are discussed. Incineration solid residues were sampled from the cyclone, downstream the furnace ( cyclone ash, CA), and from the bag filter ( filter ash, FA). Different techniques were used by the Mechanical and Industrial Engineering Department of the "Roma TRE" University, which cooperated with IRSA in the research project, to characterize incineration products and to correlate with process parameters. The X-ray Diffraction (XRD) technique was used to estimate the amount of sand, lost from the furnace, in CA and FA samples. Particle size distribution was measured using Low Angle Laser Light Scattering (LALLS). Scanning Electron Microscopy associated with Energy Dispersive Spectroscopy (SEM/EDS) was used to correlate size and shape of individual particles with chemical composition. This multifaceted approach to characterize incineration residues appears promising, providing additional and complementary information to the traditional chemical characterization

Microbial diversity in innovative mesophilic/thermophilic temperature-phased anaerobic digestion of sludge

n/