In five-star hotels, hundreds of litres of used cooking oil is thrown away as waste. Sometimes, they sell the oil to street-side food vendors at Rs 20 per litre. Or, soap manufacturers buy it from them. But now, a college in Nitte, about 50 kilometres from Mangalore, uses the wasted cooking oil as fuel for its vehicles.
The Mahalinga Adyanthaya Memorial Institute of Technology (NMAMIT) in the Udupi district is converting used cooking oil into biodiesel, which they use to fuel their buses.
The biotechnology engineering department of NMAMIT, head by C Vaman Rao, and his team of students, are on a mission to promote alternative sources of fuel for a cleaner environment.
In India, most of the biodiesel is produced from seeds such as simaruba, neem, castor and jatropha.
However, sourcing these seeds is sometimes difficult and expensive in areas where it does not grow. The cost of transporting the seeds, along with its sale price of Rs 22 to 26, makes it an unviable option for conversion to biofuel.
“In the end, the production cost of biodiesel made from seeds ends up at Rs 65 per litre, whereas petrol diesel costs Rs 47,” he said. “Because of this, we started looking for an alternative source.” Used cooking oil can be bought from hotels at a rate of Rs 20 per litre.
“We approached hotels and tried to convince them of the benefits of our project to convert it into biodiesel,” he said. When they agreed, they placed barrels in five-star hotels, large restaurants and bakeries to procure their used cooking oil, which is set to collect once every month.
Through a process called transesterification, this oil is converted into biodiesel.
Used oil is already processed, which cuts down on production time and effort. One litre of oil can produce 95% biodiesel and 5% glycerine. After this, diesel and biodiesel are mixed in the ratio of 80:20.
Besides being economical (at Rs 40 per litre, compared to Rs 47 for diesel), the institute claims that biodiesel can increase mileage by 1 to 1.5 kilometres. “It also reduces the emission of noxious gases like carbon and hydrocarbon by 35%,” said Rao. Biodiesel is also good for machines, owing to its cleansing properties.
The institute plans to use biodiesel in generators and its buses. They are already using it on one of their buses on an experimental basis for the past two months. “Right now, we have a 50 litre reactor. Once we can increase the capacity of production, we will use it in all our buses,” Rao adds.
“The idea of converting used cooking oil to biodiesel has only been a theory for several years because so far we don’t face a shortage of diesel,” he said. “However, the need for alternative sources is slowly picking up. Biodiesel and bio-ethanol are upcoming sources of green energy.”
In the US and Brazil, biodiesel has helped the countries to reduce their import of crude oil. But in India, nearly 80% of its crude oil goes into vehicles and transportation purposes.