Biofuel: Solution to energy crisis

Moratuwa University’s biofuel initiative

Sugarcane cultivation

Sixty percent of oil imported to Sri Lanka is used in the transportation sector. According to the latest Central Bank Annual Report, the Sri Lankan Government spent USD 2,496.8 million on petroleum in 2007, which is 22.1 percent of total imports.
Finding an alternative for fossil fuel has been on the table for discussion ever since Limits to growth foretold the imminent depletion of all fossil fuel deposits. One such alternative, the production of biofuel, for all the debate and controversy that surrounds it, is still practiced in developed countries.
As the major controversy in biofuel production concerns the use of edible feedstocks, scientists the world over, are now focused on exploiting non-edibles. The production of biodiesel using oil-bearing crops such as coconut, palm and jatropha is not unheard of in Sri Lanka, but large-scale experiments have not yet been conducted.
The Brazilian transportation service depends 100 percent on ethanol and the US 20 percent. Unfortunately, Sri Lanka is lagging behind. Although jatropha is a potential candidate for biofuel production, there isn’t enough acreage. However, there is still much hope for Sri Lanka’s transport industry. The University of Moratuwa has tested methane, acquired from biogas and landfills, as fuel for three-wheelers and is now focusing on biodiesel and ethanol.
“As Sri Lankans, the time has come for us to think of alternatives. The technology already exists. We just have to be more organized in terms of determining feedstock,” said Dr. Marliya Ismail and Dr. Sanja Gunawardena of the Department of Chemical and Process Engineering, University of Moratuwa. Their research which initially started as a student project using coconut oil to produce biodiesel has now moved on to vegetable oil as well as non-edible oils such as neem, jatropha, and rubber seed.

Dr. Sanja Gunawardena

“At first we used waste vegetable oil from KFC and subjected it to a chemical conversion.” Gunawardena explained. What is called the transesterification process involves mixing the oil with alcohol. This breaks the mixture into two compounds - Ester and glycerol. While Ester is used as biodiesel, glycerol need not go to waste, since it can be used in pharmaceutical products. But producing biodiesel from waste oil entails a host of other problems. All oils are triglycerides and have a high concentration of Free Fatty Acids (FFA), especially non-refined oils from plant extracts. An excess of FFA requires a pretreatment esterification process, especially in the case of non-edibles.
“If not, we end up with soap.” Gunawardena explained that soap is produced using the same esterification process. Soap reduces the efficiency of biodiesel. “We have tested many oils and can optimize the process,” said Ismail.

Dr. Marliya Ismail

“Cultivating jatropha on either side of railway tracks as proposed and yielding its harvest seems far-fetched considering that there is an alternative already available in abundance and ready to be harvested,” said Gunawardena. However, considering feedstock, the most viable alternative - according to Gunawardena and Ismail - is rubber seed oil.
A fraction of the total rubber seed oil potential is currently used in the paint and soap industries. “But the rest gets dried up unused.” There are 180,000 hectares of rubber cultivation in Sri Lanka. Hypothetically speaking, if 75 percent of the seeds from these trees are collected and the extracted fuel has an efficiency of 65 percent, it can supply 14 percent of railway sector diesel requirements. The total Sri Lankan rubber seed oil potential is 5,000 tonnes.
Gunawardena explained that, although the calorific value of biodiesel is lower than that of petroleum diesel and, as a consequence, yields less mileage, it has added advantages. Ismail explained that the biodiesel extracted from rubber seed oil emits no harmful fumes and is eco-friendly. Moreover, engines will not require special mechanical modifications to use this new fuel.
She further explained that the rubber seed oil for their research was obtained from a local mill and the chemicals from Pettah. “The chemicals we use in the process of esterification are very expensive, and we buy them at retail value. The wholesale prices may be much less.” Consequently, the research expense was considerably high, although mass production of biodiesel using rubber seed oil, according to them, will be more economically viable than diesel in the long run.
Although Sri Lanka is not self-sufficient in sugar and sugarcane has to be cultivated in excess to supply the required amount of ethyl alcohol, ethanol is yet another promising alternative considering the fact that only 18,000 hectares are used out of nearly 70,000 hectares recommended for sugarcane cultivation, by the Mahaweli Project.
As explained by Himantha Cooray, a temporary lecturer at the Department of Chemical and Process Engineering, University of Moratuwa, alcohol derived from sugarcane needs to be purified or concentrated through dehydration in order to be mixed with petroleum to make ‘Alcatrol’. “If alcohol contains water, it does not mix with petroleum. The extraction has to be 99 percent alcohol to be mixable.”

Three-wheeler donated by Cargills 
for the research

He explained that the Pelwatte Sugar Corporation currently produces 95 percent alcohol for potable purposes. “But getting from 95 to 99 percent is the challenge.” Cooray explained that the current method available for this purification process - adsorption - is expensive, due to the high energy consumption and consequently not cost-effective. It involves running the alcohol through a medium that extracts the water content in the alcohol.
Although Cooray said that he cannot reveal the mechanism behind it, because he is in the process of obtaining a patent, the ingenious new method that he has developed can produce 99 percent concentrated alcohol with just 15 percent of the energy consumed by other methods currently available.
But no alternative is worthwhile if it leads to environmental degradation. Vouching for Alcatrol’s eco-friendliness, Cooray said, “engines require oxygen to operate and since Alcatrol consists of oxygen, a natural oxygenation process takes place inside the engine.”
Just as in the case of biodiesel, no modification of the engine is required. Most importantly, he pointed out that ethanol acts as an octane number enhancer. The octane rating of Alcatrol is more impressive than that of petroleum, with an octane number of 95. Therefore it yields greater mileage.
As combustion efficiency is increased and fuel residue reduced, the emission of toxic gasses is also cut down. Moreover, considering the critical role it plays in global warming, CO2 emission is a major criterion in determining the viability of alternatives. Cooray explained that, unlike fossil fuel, the net CO2 emission of biofuel is considered as ‘0’.
“Ethanol burns CO2 trapped in sugarcane, which the sugarcane extracted from the atmosphere. So technically we are burning, back into the atmosphere, CO2 originally extracted from the atmosphere.” According to him, it’s a cyclic phenomenon where ‘0’ net emission can be achieved, consequently posing little or no environmental damage. Cooray pointed out that whatever the amount of fossil fuel the country requires, it must be imported. “Alcatrol is produced in Sri Lanka. By using Alcatrol we can finally be ‘energy secure’.”
Professor Ajith de Alwis, Head of the Department, Chemical and Process Engineering, University of Moratuwa, explained that the fuel bill of Sri Lanka has now exceeded the revenue from export crops like tea, coconut, and rubber.
Other Asian countries have high hopes for biofuel. “But Sri Lanka is sadly lagging behind,” said de Alwis. Moreover, he pointed out that the production of biofuel is the best and most effective method to pump money into those underprivileged marginal lands, such as Monaragala, as potential areas for diesel-yielding crop cultivation, which would be a boon with added benefits that the industry entails, such as job opportunities.
“We have biodiesel, ethanol, and biogas, all three types of biofuel. If we just used the alcohol not to drink but to ‘blend’, it would also fit well with the President’s ‘Mathata thitha’ policy,” concluded de Alwis.
Pics by Iresha Waduge
The article was originally published in The Sunday Observer

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