CASE Explores Biogas as Energy Alternative


The College of Agriculture, Science and Education (CASE) is conducting research into the use of biogas as a viable alternative for generating electricity.
Senior lecturer in the Department of Animal Science at the college, Dr. Paul Logan, tells JIS News that the research entails the conversion of pig excrement into biogas and using it to generate power. He adds that the project, which is being undertaken by final year students in the faculty, is part of a larger renewable energy venture being undertaken by the college.
“We have a plant, where we produce biogas from pig faeces. The research is about using the biogas produced to generate electricity,” outlines Dr. Logan, who is supervising the students’ project.
He explains that the college has a generator, which is powered by diesel and biogas. “The generator is started with diesel, and the biogas is introduced after a few minutes. In so doing, a portion of the diesel is substituted with biogas so there is a saving on the amount of diesel used to generate electricity,” Dr. Logan explains.
In outlining the biogas production process, the CASE lecturer says the fecal matter is placed in a machine called an agricultural digester along with “special bacteria”, which converts the waste to carbon dioxide and methane. The methane, he says, is used for heating, lighting, and the production of electricity, etc.”
Once the biogas has been produced, pipes are attached to the digester and also connected to the machine or equipment to be powered, resulting in the gas flowing accordingly.
Dr. Logan explains that the biogas is “introduced along with the air used to operate the generator’s engine. Once the generator senses that there is a richer mixture (of fuel) entering the engine, its (engine) speed increases and the generator will cut down on the amount of diesel (needed) to keep the speed constant”. This, he tells JIS News, is to ensure that the electricity output is consistent with the voltage that the particular circuitry can accommodate.
He notes that the pig unit is self-sufficient in energy, as biogas is combined with solar energy and diesel to create a hybrid system.
“We have security lights, a refrigerator to store vaccine, and during the colder months, when the piglets need supplemental warmth, we either use biogas directly to provide that heat source or we can convert the biogas into electricity and use it for that purpose as well,” he discloses.
In the meantime, the CASE lecturer discloses that the students are currently trying to measure the level of diesel substitution possible using biogas. “The machine can go to a point (using biogas), we have been told by researchers in India, where it can substitute up to 90 per cent of the diesel that would normally be used,” he points out.
He says the college has done some research but the results have been inconsistent. “There are days when we get as much as (an) 85 per cent (reduction) and other days when we get as little as 50 per cent,” he points out.
“What we are thinking is that the way in which we are measuring (diesel reduction) is not very precise and we’ll have to work on that because the fluctuation is not supposed to be so wide,” the lecturer reasons.
He tells JIS News that the ultimate goal is to enhance the college hybrid renewable energy project, incorporating solar energy, with biogas as a sustainable alternative.

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