Title: Biogas production from sunn hemp

Authors: Nusara Sinbuathong; Roj Khun-Anake; Suriya Sawanon

Addresses: Scientific Equipment and Research Division, Kasetsart University Research and Development Institute, Kasetsart University, Bangkok 10900, Thailand ' Department of Environmental Science, Faculty of Science and Technology, Thammasat University, Pathumtani 12121, Thailand ' Department of Animal Science, Faculty of Agriculture at Kamphaeng Saen, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand

Abstract: Sunn hemp at a cutting age of 50 days was investigated for biogas production by studying the anaerobic digestion of sunn hemp alone and the co-digestion of sunn hemp with cow dung at a concentration of 20% by fresh weight but with various proportions. The single-stage, semi-continuous reactors were operated at a hydraulic retention time of 40 days. Mixed ruminal microorganisms from cows were used as inoculum. The results indicated that the CH₄ content from the digestion of sunn hemp alone was 47.57% and the CH₄ produced per area of cultivation was 9,231 m³/hectare.year. Co-digestion could increase the CH₄ content to greater than 50%. Proportion of sunn hemp:cow dung:water of 10:10:80 by fresh weight was optimal for co-digestion. At this recommended ratio, the CH₄ yield reached 412 L/kg total volatiles solids degraded. Sunn hemp could be a very good renewable energy source for biogas production.

Keywords: anaerobic digestion; bioenergy; biogas; co-digestion; cover crop; cow dung; global warming; green manure; methane; renewable energy; sunn hemp.

DOI: 10.1504/IJGW.2019.101769

International Journal of Global Warming, 2019 Vol.19 No.1/2, pp.24 - 36

Received: 04 Oct 2018
Accepted: 09 Jan 2019
Published online: 26 Aug 2019 *

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