Viesel Fuel upgrades to enzymatic biodiesel production

Florida-based Viesel Fuel owner Stu Lamb talks with Biodiesel Magazine about his plant's recent process technology upgrade
By Ron Kotrba | July 24, 2013

After flying under the radar for the past six months, Florida-based Viesel Fuel owner Stu Lamb talks with Biodiesel Magazine about retooling his plant to produce biodiesel with Novozymes enzymes, one of only a few biodiesel plants in the world to accomplish this.

Lamb has been in the biofuel production business for seven years making a renewable heating oil additive, but once the 50-cent alternative fuel mixture credit disappeared, he made the decision to get into the biodiesel business. Lamb says he didn’t want to go the conventional route though.

“It’s a lot less expensive to go enzymatic,” Lamb says. “It’s all ambient temperatures, there’s no need for stainless tanks and pressure vessels.” Going enzymatic opens up many new feedstock choices too, allowing use of material with up to 100 percent free fatty acid content. In addition, the process requires less methanol and produces technical-grade glycerin that’s “as pure as freshly fallen snow,” Lamb says. The liquid enzymes can be used 10 to 15 times before replacing.

There was a great deal of collaboration with Novozymes’ lab and sales crews, particularly to understand in what environment the enzymes work best. “You have to treat them like a lady,” Lamb says of the enzymes. Novozymes gave Viesel Fuel the parameters in which the enzymes will perform, and the in-house engineering was tailored to those parameters.

Lamb says Viesel Fuel employs used cooking oil as a feedstock, and has even experimented with brown grease and fish oil. “Brown grease prices are realistic, you can even truck it 1,500 miles if necessary and it is still economical,” he says.

Here’s how the process works. After an extensive feedstock cleaning process using filtration, centrifugation and a caustic treatment, the prepped feedstock is then filtered again through a 1 micron filter and checked for its alkalinity before mixing with the liquid enzymes and methanol in the plastic reactor tank. Minute-by-minute monitoring of the reaction allows the operator to know when the reaction is complete. The product is allowed to settle before extracting the glycerin and demethylating the fuel. Lamb says the plant uses a proprietary resin process to polish the fuel before sending it to the final stage, a vacuum tower to remove water. Additionally, a proprietary ultrafiltration system is used to extract the enzymes from the glycerin for reuse.

“We’re very proud of this,” Lamb says. “You can build a plant like this for 20 cents on the dollar, minus the land and building, using all off-the-shelf equipment.”

By the end of the year Lamb expects about 2 million gallons of production. He says next year Viesel Fuel is primed to produce between 5 and 7 million gallons, depending on how much feedstock the plant can secure.

He says the tax credits the biodiesel industry has become reliant on will eventually disappear, and when that happens, Viesel Fuel will be in a position to remain a true low-cost producer of biodiesel.