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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