More than 200 people who wanted to learn how to make biodiesel in small batches recently packed a meeting room at the LSU AgCenter’s W.A. Callegari Environmental Center in Baton Rouge to attend a workshop and demonstration on how to make biodiesel from used vegetable oil, said Bill Carney, LSU AgCenter environmental educator.

Carney repeated a 90-minute workshop each day and followed it with a demonstration on making the fuel in a 50-gallon reactor. “The process takes 48 hours,” Carney said.

The first day, Carney loaded the reactor with used vegetable oil. The second day, he drained glycerin from the reactor and started a wash process. The third day, the process was virtually completed.

When the reactor ended its cycle following the third workshop, the biodiesel still had a water content higher than desirable.

“We want to get the water down to 0.05 percent,” Carney said. But the humidity of south Louisiana in June slowed down the drying process. He said additional drying over night would be necessary to bring the moisture level down.

Biodiesel is made through a process called transesterification, where vegetable oil is combined with methanol and lye, according to Gary Breitenbeck, a researcher with the LSU AgCenter.

Vegetable oil consists of lipids — triglycerides containing fatty acids — Breitenbeck said. The methanol displaces the glycerin and combines with the fatty acids to produce a fuel that performs as well as petroleum diesel.

The lye simply serves as a catalyst, he said. And the process also yields glycerin, which is used in the production of soaps, cosmetics and a host of other products.

Carney said he was surprised at the attendance at the workshops. He said the audience over the three workshops included lawyers, engineers, oil company employees, small business operators and others.

For the workshop, Carney combined 50 gallons of used vegetable oil with 20 gallons of methanol to produce 50 gallons of biodiesel and 12 gallons of glycerin.

“The process yields a one-to-one ratio of biodiesel to vegetable oil,” he said.

Carney said for an investment of under $1,000, people can make about 25 to 30 gallons of biodiesel at a time.

“For about $8,000 — the cost for a more automated process — you can make 50-gallon batches,” Carney said. “This is the setup we have at the Callegari Center.”

Beyond that amount, it becomes more difficult for the small operator to acquire enough vegetable oil to justify the cost, Carney said.

Based on the turnout for these workshops, Carney said he plans to offer more workshops. “We closed registration, and we had standing-room only every day,” he said.