Ensiling of crops for biogas production: effects on methane yield and total solids determination

Biotechnology for Biofuels

Lovisa Björnsson¹  Ivo Achu Nges¹  Emma Kreuger¹ 

[1]Department of Biotechnology, Lund University, PO Box 124, SE-22100, Lund, Sweden

关键词: silage;    ensiling;    volatile solids;    total solids;    dry matter;    volatile fatty acids;    ethanol;    biofuel;    methane potential;    anaerobic digestion;    biogas;   

Others  :  798394
DOI  :  10.1186/1754-6834-4-44

 received in 2011-06-21, accepted in 2011-10-27,  发布年份 2011

【 摘 要 】

Background

Ensiling is a common method of preserving energy crops for anaerobic digestion, and many scientific studies report that ensiling increases the methane yield. In this study, the ensiling process and the methane yields before and after ensiling were studied for four crop materials.

Results

The changes in wet weight and total solids (TS) during ensiling were small and the loss of energy negligible. The methane yields related to wet weight and to volatile solids (VS) were not significantly different before and after ensiling when the VS were corrected for loss of volatile compounds during TS and VS determination. However, when the TS were measured according to standard methods and not corrected for losses of volatile compounds, the TS loss during ensiling was overestimated for maize and sugar beet. The same methodological error leads to overestimation of methane yields; when TS and VS were not corrected the methane yield appeared to be 51% higher for ensiled than fresh sugar beet.

Conclusions

Ensiling did not increase the methane yield of the studied crops. Published methane yields, as well as other information on silage related to uncorrected amounts of TS and VS, should be regarded with caution.

【 授权许可】

   
2011 Kreuger et al; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

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