May 9, 2012
BY Ron Kotrba
Pearland, Texas-based Biodiesel Experts International and Israeli enzyme company TransBiodiesel have formed a joint working relationship where BEI will supply an engineering package or a complete enzymatic biodiesel plant and, in turn, TransBiodiesel will supply enzymatic material for the commercial production of biodiesel. The companies say with BEI supplying either an engineering package or complete enzymatic plant comes assurance that the enzymes will perform in an industrial environment suitable to achieve maximum biodiesel production potential.
“This is a great process,” said Ernie DeMartino, BEI president and CEO, “because it’s so forgiving.” Like other enzymatic techniques under development, the TransBiodiesel enzymes can use hydrous feedstock and methanol or ethanol, cheaper than their dehydrated versions, without the worry of producing soaps that would otherwise result if wet feedstock and alcohol were reacted with caustic. Also, the reaction temperatures are much lower than conventional processing, 85 degrees Fahrenheit. The process can also take in nearly any feedstock, including a variety of mystery mixes.
“The feedstock has to be fluid at 85 degrees though,” DeMartino said. For feedstocks that are not fluid at this temperature, DeMartino said they can be blended down with waste vegetable oil or biodiesel that can be recycled before running through the process.
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BEI has been receiving supplies of corn oil feedstock from a major U.S. ethanol producer for testing. Using 15 percent methanol by weight and a buffer solution to protect enzymes and aide reaction, DeMartino said the two-stage, paddle-stirred reaction gives way to beautiful, red-colored biodiesel people have come to expect from post-fermentation corn oil. “The enzymes do something to the waxes that transforms them,” DeMartino told Biodiesel Magazine. “The wax will convert into part of the methyl ester. When it’s chill to 40 degrees, we never lose fluidity of it.”
Prior to developing this joint working relationship, the two companies had been working together in a knowledge and information transfer arrangement, said DeMartino, with TransBiodiesel providing enzymatic material and Biodiesel Experts International working out the industrial process kinks. “I’ve been working to perfect the process,” DeMartino said of the past year leading up to the new relationship between the two firms.
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When he first started working on developing the BEI industrial process using TransBiodiesel enzymes, he said it was difficult to meter in the methanol at such low doses in his lab setup. “If you put too much methanol in too quickly, you’ll kill the enzymes,” DeMartino said.
Regarding enzyme activity, loading and price, DeMartino said a conservative estimate he uses is 1 kilogram of enzymes can process 3,000 kg of feedstock. Put another way, 1 kg of enzymes can produce 800 gallons of fuel. But DeMartino said he is seeing rates more along the lines of 1 kg of enzymes can process 1,600 gallons of fuel. The enzymes, which cost between 37 and 42 cents per gallon of fuel produced, take a little time to become fully active when they are first introduced to the process, and quickly reach full performance until levels decrease as their full useful life draws to close.
“A lot of producers want to go the enzymatic route,” DeMartino said, “but they have no feeling on how long the enzymes will last.”
TransBiodiesel enzymes are currently used in the Green City plant in Israel, and in two other facilities in Utah and Canada, and DeMartino said now that BEI is providing process design and engineering to use TransBiodiesel enzymes, he has a lot of orders sitting on his desk as he waits for some important, last-minute test data to arrive from Israel.