A new biodiesel production technology developed at the University of Connecticut will soon be offered commercially. The innovative system features a continuous flow reactor that separates biodiesel from glycerin in one step.

The patented technology has been under development for approximately three years. According to UConn Professor of Chemical Engineering Richard Parnas, a primary motivation in developing the system was that most biodiesel technology has been centered on batch reactors. “What the chemical processing industry has learned over the last 100-some odd years is that if you can do your processing in a continuous reactor, that’s typically much more efficient and cost effective,” he said.

Taking the idea another step forward, Parnas also identified an opportunity to combine the reaction step with glycerin separation. “Sometimes separations can cost more than the reactions,” Parnas continued. “As we were developing our continuous reactor, we recognized an opportunity to combine the glycerol separation with the actual reaction to produce the biodiesel.”

There is a chemical reaction when you combine methanol and vegetable oil to make biodiesel and glycerin, Parnas said. When you first combine vegetable oil and methanol, they separate. At the end of the reaction, biodiesel and glycerol also separate in a similar fashion to oil and vinegar in salad dressing. “In between, when you have a mixture of the vegetable oil, methanol, biodiesel and the glycerol, there is a wide range of situations where the biodiesel, vegetable oil and methanol all like each other and mix together very well, but they still don’t like the glycerol,” he continued.

The technology developed by Parnas works to capitalize on these chemical reactions. Vegetable oil and methanol are run through a mixer before they enter the reactor. “By the time they come out of the mixer into the main reactor chamber, the reaction has already gone forward 15 or 20 percent of the way,” he said. “Once that happens, you don’t have to mix anymore.” In other words, Parnas and his team discovered that once the reaction is approximately 15 to 20 percent complete, it is no longer necessary to mix the vegetable oil and methanol. The reaction will continue without additional mixing. Once the mixture is in the reactor tube the fluid flows gently, the reaction continues, and the glycerin settles out.

A primary advantage of the system is that it is less energy intensive than traditional biodiesel processes. “When you are running big reactors, just keeping them well mixed takes a lot of energy,” Parnas said. “We don’t use any energy at all, except for a couple of little pumps to just move the fluid through the reactor, but we don’t have any mixers or other high energy [equipment in the reactor].”

Parnas recently partnered with some associates outside UConn to incorporate a company called RPM Sustainable Technologies. The company has formed strategic partnerships with a local equipment manufacturing company and a local design and engineering firm.

“We are prepared to commercialize our biodiesel reactor, and a patent-pending waste oil pretreatment process,” Parnas said. “We are also prepared to process byproducts of the manufacturing process into high-value specialty chemicals. That of course improves the revenue and the financial balance for any potential project.” RPM is unable to release additional details about the high-value chemical production at this time.

The biodiesel systems will be built on skids, and can be shipped anywhere in the world. The company plans to initially focus on community-scale production systems ranging in nameplate capacity between 250,000 and 5 million gallons per year.

According to Parnas, RPM is focused on the use of sustainable, nonfood based feedstocks. “We have already documented the ability of our technology to use jatropha oil, and we are in the process of documenting our ability to use other nonfood oils as well.”

RPM’s business plan is specifically designed to be flexible. If a client simply wants to buy the equipment and set up their own plant, Parnas said the company is able to develop licensing agreements to allow that. Alternatively, if a client would like to develop a joint venture with RPM, the company is open to that as well. RPM is actively working on projects in France, Mississippi and Connecticut. “We’re also starting projects in Hawaii and Sri Lanka,” Parnas said.

A video produced by UConn that shows a lab-scale reactor in action is available on the UConn website.