Professor Petruso making fuel from tobacco leaves
Mar 28, 2011
Tobacco leaves used to make bio fuel
By Annmarie Ely
At A-Day a tractor ran all day on three gallons of fuel that chemistry professor Ronald Petruso made from waste oil produced by the campus dining hall.
“It smelled like we were frying chicken wings,” Petruso said of the scent that came out the tractor’s exhaust. It left a white or bluish-white vapor instead of the typical black cloud produced by diesel fuel. And the best part? The idling tractor wasn’t producing pollutants.
Petruso was able to power the same machine, getting the same mileage, in a cheaper, more environmentally friendly way while recycling campus waste.
Now he is back at work, to see if he can use tobacco leaves to produce a similar result. Research on using tobacco for biodiesel fuel is relatively new.
Petruso has been researching biodiesel fuels for about three years. Biodiesel can be used to power any diesel vehicle or for home heating. It is clean burning and efficient.
He has used coffee grounds from a Starbucks to produce a clean fuel, which produced a slight coffee smell.
“Everything we’re doing is done for the purpose of minimizing dependence on oil and keeping the environment clean,” said Petruso. “We want to be part of the solution.”
The chemistry professor, who caught national attention in 2008 by identifying potentially carcinogenic substances in tattoo pigment, has been working with tobacco for about a year. The research is being funded by a $3,000 faculty development grant.
The professor chose tobacco because its use doesn’t deplete the food supply. He also wants to help tobacco farmers being hurt by the high tax on tobacco products, new regulations and fewer people smoking.
“Ethanol is not the way to go,” Petruso said of the corn-based fuel. “We need corn. I just thought there’s not a lot going on with tobacco.”
He also wanted to give students an idea of what real world research projects are like to make them more marketable to employers.
Turning tobacco leaves into the straw-colored biodiesel fuel is no easy task.
Petruso grows a variety of plants that produce good quality oil. He currently has more than 300 in the campus greenhouse. After the leaves are cured and dried, they are ground into a fine powder.
Then using a solvent he removes the oil from the powdery substance. He experimented with several solvents. The solvent needed to be low in cost and he wanted to be able to reuse it. Petruso found that hexane, which comes from petroleum, met both requirements.
During the extraction process, a machine runs for hours. He then has to separate the hexane from the oil using an evaporation process.
“Now we have our oil,” said Petruso.
Using a simple distillation process, he makes sure the liquid is pure. He analyzes it using a mass spectrometer.
The professor then converts the oil to fuel using a long chemical process called esterification. Through transesterification, the reverse process, he gets rid of unwanted materials.
Then he runs an analysis using a mass spectrometer. He tests the fuel to see how much heat it is giving off. He also uses a viscometer to check to see if the oil has the right thickness.
“Is it like water or too oily?” said Petruso. “You need the right thickness.”
If the fuel is too viscous it can freeze when the weather gets really cold. It is sometimes mixed with regular diesel to prevent freezing.
He has four seniors who help him with the research: Melissa Brown, Catherine Kita, Andy Sterling, and Brandon Rush. With the exception of one student, they are all there every Friday night from 4:30 to 9:00 p.m. to help.
“I want to get the students involved,” said Petruso. “I want them to apply themselves to solving everyday problems.”
The students wear masks and gloves for protection. They are careful with the oil, which produces a strong odor and is highly concentrated with nicotinic acid.
“Interest is a big thing,” said Petruso of choosing student researchers. He said students he chooses are dedicated, dependable, self-sufficient and take pride in their work.
“A student who says, ‘Oh, that’s close enough.’ I don’t want them in the lab,” said Petruso.
A former student, Jacob Serafin, used research he did with Petruso as part of his interview to get into a graduate program.
Petruso said he will probably continue perfecting the process until December. He is focusing on making the fuel in the most cost effective, simple process while making good use of any waste material.
One of his waste products, glycerol, can be used to make soap or put in the ground so gardeners don’t have to do as much watering.
Once the fuel is produced it has to meet Environmental Protection Agency standards. It takes about 25 plants (depending on the size and amount of leaves) to make one gallon of fuel. So far, the professor has produced approximately a quarter of a liter. When the group produces enough to test in the campus tractor,
Petruso will analyze the exhaust for unwanted particles.
Petruso said past biodiesel fuels he’s made have powered the campus tractor for a little more than two months worth of runs around campus. The diesel lawn tractor has a three gallon tank. He thinks it is possible that tobacco will produce similar results, but said the important point about biodiesel is not mileage. It is the relatively non-polluting exhaust vapor.
“We have more experimenting to do yet,” said Petruso.
There’s little room for mistakes when creating biodiesel fuel. The fuel won’t work or can clog an engine if it is not right. Petruso said you have to make a point to get the fuel as pure as possible and grow and cure the plants properly. He said bacteria can eat up your fuel and “once that happens you’re in big trouble.”
Biodiesel fuel cleans the engine, but that’s not always a good thing. Petruso said if an engine is too clean it can ruin the seals.
Then you have to make sure the volume of fuel you are producing is worth the money you’re putting in to it.
While the process isn’t without its risks the professor says he’s a firm believer in taking chances.
“You have to play the lottery in order to win,” said Petruso.
He hopes to publish his research and see if the process can be adopted on a larger scale.
The chemistry professor is excited about future research. His next intended project is finding a cost efficient way to hand chemical waste.
He pulled out a disk about an inch thick with the diameter of a teacup saucer and held it in his bare hand. The cement-like disk is made of once toxic chemicals, which Petruso has been able to stabilize or make safe enough to throw out in a regular trashcan.
By stabilizing and solidifying toxic chemicals from areas such as campus labs Petruso thinks he may be able to save the college thousands of dollars in disposal fees.