Low-temperature anaerobic digestion of swine manure in a plug-flow reactor.

Massé, D.I., Gilbert, Y., Cata Saady, N.M., and Liu, C. (2013). "Low-temperature anaerobic digestion of swine manure in a plug-flow reactor.", Environmental Technology. doi : 10.1080/09593330.2013.781229  Access to full text

Abstract

A low temperature (25 °C) anaerobic 8-compartments (PF01 to PF08) cascade reactor simulating plug flow reactor (PFR) treating pig manure was monitored for a year. The bioreactor was fed at an average loading rate of 2.4 ± 0.2 g of total chemical oxygen demand (TCOD) per litre of reactor per day for a theoretical HRT of 67 ± 7 days. An average of 79% of TCOD was removed from pig manure (converted into biogas and in sediments), whereas specific methane yields ranging from 397 to 482 NL CH4 kg-1 VS (148.6 to 171.4 NL CH4 kg-1 TCOD) were obtained. After 150 days, fluctuating performances of the process were observed associated with solids accumulation in the upstream compartments, preventing the complete anaerobic digestion of swine manure in the compartments PF01 to PF04. Low temperature anaerobic PFR represents an interesting alternative for the treatment of pig manure and recovery of green energy. Further investigations regarding a modified design, with better accumulating solids management, are needed to optimize the performance of this low temperature PFR treating pig manure.

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