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We could do more with all this pig excrement

SCIENTISTS AROUND the world are working hard to come up with novel ways to preserve natural resources.

One proactive measure that deserves more attention is the creation of combined anaerobic sludge processing systems that turn pig feces into biogas energy, with the added benefit of also producing organic fertilizer, satisfying both environmental and energy needs.

In recent years, the EU and countries such as the US, Japan, Thailand, Chile, Sweden and China have been increasing their efforts toward finding alternative energy sources.

Since the passing of renewable energy legislation in Germany in 2000, rural areas have been trying to maximize the use of renewable energy sources. The German town of Goettingen started a model renewable energy village cooperative in September 2005, with pig farmers being part of the organization. It aims for self-provision of thermal energy and sells any surplus electricity.

Chile has a farm with 120,000 pigs that uses covered single tank fermentation and an all-in, all-out management system that successfully converts pig feces to biogas. Chaoren Pokphand Enterprise in Thailand generates biogas electricity from 3,100 pigs, saving an average 23 percent in monthly electrical costs. Sweden uses organic waste and wastewater disposal to produce biogas, using it in cars and trains.

In Taiwan, as early as the mid-1970s, agricultural agencies were attempting to promote the generation of biogas from pig feces. The project to turn pig feces into green gold was unsuccessful at the time because of inadequate technology and equipment, as well as the fact that there was no severe energy shortage.

With Taiwan having almost 7 million pigs, if every pig were to produce two kilograms of waste each day, then 8.4 million cubic meters of biogas could be generated. Using 30-kilowatt generators, this would produce 161.5 million kilowatt hours of electricity.

This method not only would reduce wastewater processing fees, but would also produce biogas to replace natural gas or commercial electricity. In addition, the organic fertilizer from the sludge that would be produced could be used or sold, eliminating environmental damage from pig farming as well as creating additional profit.

To realize the scheme of turning pig feces into green gold, agricultural authorities and pig farmers must cooperate.

We should modify pig waste processing plants, which have low efficiency and efficacy at present, by transforming them into fertilization facilities, so land would not need to be expropriated for this purpose.

We should also form cooperatives, as most pig farms operate on a relatively small scale.

Agricultural authorities need to prioritize Pingtung and Yunlin counties, as these areas have the highest concentration of pig farms and form a renewable energy model village that uses both pig feces and agricultural produce as biomass.

Lastly, we should implement policies such as energy purchasing and investment incentives and provide education on the use of biogas.

As Taiwan has yet to establish renewable energy legislation -- and current energy developments have been focused on solar and wind power, which both require high costs and high technological standards -- the potential of pig feces for biogas has been neglected.

In order to take care of both energy and environmental issues, the government should turn to pig feces, which can eliminate not only the burden of using land for biomass crops, but also provide a new lease on life for pig farmers.

Huang Wan-tran is the vice president of the Chung Chou Institute of Technology.

Translated by Angela Hong
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