Improvement in CH4/CO2 ratio and CH4 yield as related to biomass mix composition during anaerobic co-digestion. (March 2017)

• Record Type: Journal Article
• Authors: Poulsen, Tjalfe G.; Adelard, Laetitia; Wells, Mona
• Is Part Of: Waste management. Volume 61(2017)
• Page Start: 179
• Page End: 187
• Publication Date: 2017-03
• Subjects: Mono- and co-digestion -- Ultimate CH4/CO2 ratio -- Ultimate methane yield -- Relative improvement -- Optimal biomass mix composition -- Biomass waste materials; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2016.11.009
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: Mono- vs co-digestion of 9 biomasses (145 ternary biomass mixes) investigated. Ultimate CH4 yield and CH4 /CO2 ratio significantly higher for co-digestion. Ultimate CH4 yield 27% higher for co-digestion across all mixes. Optimal ultimate CH4 yield 65% higher for co-digestion across all mixes. Abstract: Sixteen data sets (two of which were measured in this study) with a combined total of 145 measurements of ultimate methane yield (UMY) during mono- and co-digestion of ternary biomass mixtures were used to assess impact of co-digestion on the relative change in UMY (Δ UMY ) as a function of biomass mix composition. The data involved 9 biomass materials (brewery spent grains, chicken manure, cow manure, fresh grass clippings, pig manure, primary sewage sludge, vegetable food waste, wheat straw, and rice straw). Results of the assessment shows that co-digestion in 85% of yields positive values of Δ UMY regardless of the biomass materials used, however, a smaller fraction (15%) resulted in negative Δ UMY during co-digestion. The data further indicate that for each set of ternary biomass material mixtures there exists an optimal biomass mix composition at which Δ UMY is at a maximum. Statistical analyses based on the data used here indicate that the maximum value of Δ UMY (Δ UMYmax ) is always positive regardless of biomass materials being co-digested.