Biogas System Effective in Reducing Environmental Degradation

This week I went to visit Zhen He Neng Yuan (振和能原), one of two private biogas companies in Yunnan. Zhen He Neng Yuan was founded in June of 2009 at around the same time as the other private biogas factory farmscompany, Hong Biao. Zhen He Neng Yuan produces large scale cement bio-gas digesters for , specifically farms with other 3,000 livestock. Due to environmental protection regulations, factory farms must build a system to properly manage manure, and biogas is a perfect solution to effectively manage waste and create energy. The government provides significant subsidies to factories to build these biogas digesters, ranging from 10,000 to 30,000 RMB ($1,500-$4,200). Without government subsidies, these factory farms would be unable to purchase these biogas digesters. Currently, the company has sold biogas digesters to three factory farms, and will sell two more in the next few months. The company is also planning on building a large biogas digester for the community outside of Lijiang, Yunnan, in Lashi Wetland(拉市海), in order to effectively manage the waste created by the horse riding tourism industry. The biogas digester will divert waste from entering the nearby wetland, and the energy created from biogas can power the fuel needs for a restaurant.

Zhen He Neng Yuan is the only private company in Yunnan that repairs and maintains household biogas digesters. The company also plans to build three communal digesters in the surrounding community of their research center in Yi Liang County. Each village (servicing 150 families) would be provided with a digester, and one or two community members in the village would be trained to upkeep the biogas digester. While having a communal digester may be more promising in encouraging the uptake of this technology, farmers will need to be economically incentivized to collect and carry their animal waste into a central location. The communal digesters in Dali City, Er Yuan County, has been successful because the government gives farmers 40 RMB (approximately $5.50) for each ton of manure they bring to the biogas station. While environmental education is essential to encourage farmers to voluntarily use and maintain their biogas digesters, providing economic incentives in the short term is the best motivator to sustain biogas use.

While the current dialogue on climate change centers on greenhouse gas emissions from industrialized sectors, little media attention is given to the impact factory farms have on climate change and environmental degradation. According to Compassion In World Farming, 10% of all anthropogenic greenhouse gas emissions come from livestock manure and bacterial fermentation, which is five times the proportion of global emissions due to air transport. On factory farms, manure is usually stored in slurry form (a mixture of urine and feces), and this slurry emits methane and nitrous oxide. When manure is spread on the field, it emits nitrous oxide and causes nitrogen pollution of land. Additionally, animal waste contaminates drinking water supplies because the nitrate stored in lagoons can easily seep into groundwater.

However, biogas systems can reduce odors caused by improperly managed manure storage tanks, because the organic acids, the odor causing compounds, are consumed by the bacteria during the fermentation process. The heated digester also reduces pathogen populations in a few days and the digester effluent (the by-product after fermentation) can serve as a high quality fertilizer. When the effluent is properly applied, it can reduce the likelihood of groundwater contamination.

In a 2008 report by the Swedish Trade Council on renewable energy in the United States, there are 100 operational biogas systems at livestock operations in the United States and 80 in the planning stages. Due to increased financial support from state and federal programs, the demand for anaerobic digesters has increased since 2005. Biogas technology is feasible at about 7,000 dairy and livestock operations. Additionally biogas digesters have the potential to generate 6 MWh/year of electricity at livestock operations.

In order to reduce the environmental degradation caused by factory farming, the government needs to implement policies that limit emission of greenhouse gases from large manure management facilities, provide subsidies to encourage farmers to purchase biogas digesters, and allow farmers to sell carbon credits. By instating this triple pronged measure, farmers will likely view biogas as an attractive technology to invest in.

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