Trinity Senior Designs a Car that Runs Flawlessly on Waste Vegetable Oil

Han Wu ‘13 converted Diesel Mercedes donated by Professor Alden Gordon

HARTFORD, CT, May 3, 2013 – Alden Gordon believes his father, who died in 1999, would have been quite pleased to learn that his 1985 Mercedes Benz, which he bequeathed to his son and which his son donated to Trinity, has been put to good use: advancing students’ knowledge of and appreciation for sustainability.

The white sedan, a little worn for the wear but otherwise in good shape, has been parked much of the time in the Trinity Commons or Buildings and Grounds parking lot waiting for lightning to strike. It did this year when Han Wu ’13, an engineering major from China, undertook as his senior project the redesign of the diesel-powered Mercedes to run on waste vegetable oil.

On Wednesday, Wu described his project during the engineering students’ senior presentations in Hallden Hall and then walked over to where the car was parked, showed observers the modifications he had made and started it right up. While it didn’t exactly purr like a kitten (what 28-year-old car would?), the Mercedes performed to the delight of onlookers, including Gordon, Paul E. Raether Distinguished Professor of Fine Arts and a Trinity alumnus.

“My father would have liked this,” said Gordon. “He was a biochemistry major in college and his son and all three of his grandchildren graduated from Trinity. There’s a nice continuity. His car was used for science at his son’s and grandsons’ alma mater.”

Pictured with the Mercedes from left to right are Han Wu '13, Engineering Professor John Mertens and Alden Gordon, Paul E. Raether Distinguished Professor of Fine Arts and the former owner of the car. Photo by Rita Law​
 Gordon and Wu’s mentor, Engineering Professor John Mertens, hope that the car can be used to benefit the College: a nice paint job, a few more modifications and the Mercedes could be used as a campus shuttle or for some other laudable purpose.

“I’d like to see the car be visible around the College and have it identified as Trinity’s Green Car,” said Gordon. “It could be used to give students rides to the airport or the train station. It would be painted with the Trinity [logo] and it would be easily recognizable.”

Although this is not the first time that a diesel car has been converted to run on waste or regular vegetable oil, which results in a significant cost savings and a smaller environmental footprint, many of the cars have run into problems, such as the car having to start on diesel fuel before switching to the vegetable oil or the fuel lines having to be purged of the vegetable oil to avoid congealing.

“In other systems, people have to drive for 10 minutes, pull over, and change the fuel. In my system, we can keep on driving,” said Wu.

In making modifications to the car – including installing a second battery, special coils, a coolant hose and a sensor-controlled heating element that heats the oil to the required 80 degrees C – the Mercedes is able to start using the vegetable oil, which Wu obtained from the Mather dining hall.

During his presentation, Wu, who has been accepted into Stanford University’s graduate program for a two-year master’s degree program in mechanical engineering, explained that being able to operate a car on a substance such as vegetable oil saves money for restaurants because they can easily dispose of the used oil, saves money for the car owners because they don’t have to buy as much diesel fuel and is better for the environment because the car doesn’t give off nearly as much greenhouse gas emissions.

However, prior to now, the conversions have mostly been done in warmer climates where heating the vegetable oil was not as much of an obstacle as it is in Connecticut.

The key to getting the car to perform was figuring out a way to heat the oil to a high enough temperature so that it wouldn’t have to rely on diesel fuel to start. Other commercially available systems, he said, need to run for 10 to 15 minutes on diesel fuel before switching to the vegetable oil. By not having to start the car on diesel fuel, it reduces the reliance on diesel and makes the car run cleaner.

“Han Wu has done a truly incredible job of analysis, design and implementation,” said Mertens. “The system is one-of-a-kind, the only one I know of that does not rely on diesel during warm-up, even in the winter.”

The car, which has racked up about 200,000, can get about 25 miles to the gallon, although it does have a somewhat limited range. Nonetheless, Mertens said he has been able to drive it in the vicinity of the College without a problem.

Wu acknowledged that the yearlong project was frustrating at times and that he “went through several designs” before he came up with one that proved successful.

“I had to be sure that it was safe and reliable and that the cost was reasonable,” said Wu, who modestly conceded that the car could still use some “fine-tuning.”

Mertens said he hopes that will happen and that other engineering students will pick up where Wu left off. There’s still work to be done on quantifying things such as mileage, acceleration, emissions and the distance it could travel.

Gordon suggested that the car could be called Arthur in honor of his father, who would have been proud to see it used in this way.​