Estimating the Methane Potential of Energy Crops: An Overview on Types of Data Sources and Their Limitations

Abstract

As the anaerobic digestion of energy crops and crop residues becomes more widely applied for bioenergy production, planners and operators of biogas plants, and farmers who consider growing such crops, have a need for information on potential biogas and methane yields. A rich body of literature reports methane yields for a variety of such materials. These data have been obtained with different testing methods. This work elaborates an overview on the types of data source available and the methods that are commonly applied to determine the methane yield of an agricultural biomass, with a focus on European crops. Limitations regarding the transferability and generalisation of data are explored, and crop methane values presented across the literature are compared. Large variations were found for reported values, which can only partially be explained by the methods applied. Most notably, the intra-crop variation of methane yield (reported values for a single crop type) was higher than the inter-crop variation (variation between different crops). The pronounced differences in reported methane yields indicate that relying on results from individual assays of candidate materials is a high-risk approach for planning biogas operations, and the ranges of values such as those presented here are essential to provide a robust basis for estimation.

Integration of Hydrothermal Carbonisation and Anaerobic Digestion for the Energy Valorisation of Grass

“…Previously reported biomethane potential values for grasses vary considerably: 222 mL CH 4 /g VS [3], 261 mL CH 4 /g VS [52], 285 mL CH 4 /g VS [15], 292 mL CH 4 /g VS [9], 308-340 mL CH 4 /g VS [13], 327 mL CH 4 /g VS [14], 341-493 mL CH 4 /g VS [53], 400 mL CH 4 /g VS [5] and 403 mL CH 4 /g VS [16]. The variation in biomethane potential values is likely due to a combination of factors, including biochemical composition, plant maturity [6], interspecies variation [54], harvest season [13] and differences between the methodologies used to determine biomethane potential [53,55]. The E BMP results of the grass used in this study correspond with those previously reported for grass silage [52] and grasses collected from a University campus [15] and sports fields [9].…”

A review on the interplay between bioeconomy and soil organic carbon stocks maintenance.

“…The AD technology Cc was determined using a compilation of the biomethane potential (BMP) values reported for different feedstocks and process conditions. BMP is defined as the specific methane production from a given substrate under specific digestion conditions [20]. Details on these calculations are in the supporting database.…”

A Comparative Analysis of Biodegradation and Bioconversion of Lentinula edodes and Other Exotic Mushrooms

“…One way to reduce these impacts is to grow crops in protected environments but this is not always possible. Crops that require large expanses of land or acreage of land, such as soybeans, wheat and corn, are examples of this [4,5]. However other crops, such as horticultural crops, and mushrooms are amenable to cultivation in protected environments.…”