title: Anaerobic co-digestion of pig manure and crude glycerol at mesophilic conditions: biogas and digestate.
abstract: Crude glycerol derived from biodiesel production is characterized by its high concentration of organic carbon and its solubility in water; properties that make it a suitable co-substrate to improve the efficiency of a manure digester. An increase of about 400% in biogas production was obtained under mesophilic conditions when pig manure was co-digested with 4% of glycerol, on a wet-basis, compared to mono-digestion. The increase in biogas production was mainly a consequence of the increase in organic loading rate. However, the differences could also be related to the synergy between both substrates and the carbon-to-nitrogen ratio. Moreover, the analysis of the macro-compounds, protein, lipids, carbohydrates and fibers, showed lower removal efficiencies in the co-digester as the microorganisms obtained nutrients from the soluble carbohydrates provided by the glycerol. The digestate stability, evaluated through a respirometric assay, showed that co-substrate addition does not exert a negative impact on digestate quality.
authors.affiliation: Department of Chemical Engineering, University of Barcelona, C/ Martí i Franquès, no. 1, 6 th floor, 08028, Barcelona, Spain. sastals@ub.edu
authors.forename: S
authors.initials: S
authors.lastname: Astals
authors.forename: V
authors.initials: V
authors.lastname: Nolla-Ardèvol
authors.forename: J
authors.initials: J
authors.lastname: Mata-Alvarez
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D056804:Biofuels; D005990:Glycerol / Q000378:metabolism*; D008372:Manure; D013552:Swine
chemical_list: D056804:Biofuels; D008372:Manure; D005990:Glycerol