A college student has invented a cheap and environment friendly process to convert kitchen waste into energy. Ubaid Yousaf Khan from Karak displayed his invention at Peshawar Press Club on Tuesday. He demanded that the federal and provincial governments establish research institutes for the young and talented youth in the country.
Ubaid, along with his collaborator Mujga of Khyber Medical College, explained the main objective of their study was to develop a process to convert kitchen waste into energy that is cheap and environment-friendly.
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“We wanted to find an environment-friendly and cheap alternative to fossil fuel as it is a known contributor to global warming, which is dangerous for the existence of human life,” Ubaid said. People are slowly turning away from fossil fuel, he said.
“Kitchen waste is rich in organic compounds. Therefore, we can produce large amounts of biogas from it,” Ubaid said.
Four years of work went into developing this project, he added. Ubaid is from Wisedom Science College in Karak, however, a large part of the project was his own initiative as well as his collaborator, Mujga.
How it works
For this process, the substrate (entity being modified) was the kitchen waste; the inoculum (organism used to start a reaction) is the waste from the sugar industry. Both were treated in an anaerobic digester (without oxygen) for 15 days under varying temperature and inoculum to substrate ratio.
It was observed biogas production was negligible in the first two days and took up to 12 days to increase. It reached a stationary phase on the fifteenth day. The culture is diluted with water in order to prevent the formation of volatile fatty acid which otherwise would decrease the production of biogas. Maximum biogas production was observed at a temperature of 35C.
The young scientists also observed biogas production was very low when only an algal biomass was treated, as it has a relatively smaller carbon to nitrogen ratio. During the biodegradability process, ammonia and volatile fatty acid (VFA) are formed, due to which the pH drops to the acidic range. This leads to the poor micro-biological activity. Therefore, it is important to select a sludge that is high in carbon to nitrogen ratio when being used with kitchen waste in the anaerobic digestion.
Ubaid said one tonne of kitchen waste can produce up to 320kg of biogas. He said biogas was produced by bacteria through the biodegradation of organic material under anaerobic conditions.
“Natural generation of biogas is an important part of biogeochemical carbon cycle. It can be used both in rural and urban areas,” he said. Additionally, Ubaid said the experiment showed them that a large quantity of biogas was produced at low inoculum to substrate ratio. Therefore, if scaled, fewer natural resources will be used in the process.
How efficient is this?
The efficiency of the process can be increased by adding distilled water to the sludge and substrate as this will reduce VFA concentration, which usually destroys the methanogens (microorganisms that produce methane as a metabolic byproduct in anaerobic conditions).
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“The total cast of this process is Rs10,500. If it is scaled for commercial proposes, the cost of the process will be Rs100,000, which will produce 320kg gas,” said Ubaid. “K-P government’s green movement can benefit through this method as biogas can be produced and its waste can be used as fertilizer,” he added.
Ubaid urged the government to open research institutes for young researchers so they can work in a professional environment rather than inside their houses as did the college student and his colleague from KMC.
Published in The Express Tribune, January 6th, 2016.
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