Southeast Biomass Conference features biodiesel panel

By Ron Kotrba | November 04, 2010

We’re just finishing up the Southeast Biomass Conference & Trade Show in Atlanta, and I thought I would share a review of the panel I moderated at the conference.

I covered the four biorefining panels at the event. Two of them I already wrote reviews for and posted them on our website, so I will give a few words on the panel I moderated with more extensive coverage on the fourth and final panel to come.

I moderated the one and only biodiesel panel at the show, Biodiesel from Waste and Low-Value Feedstock. The biodiesel industry is wonderfully diverse and the panel of speakers nicely represented that diversity.

Christina Borgese, the senior engineer and cofounder of consulting firm PreProcess Inc. discussed the importance of diesel power and how just a 2 percent blend can replace all the lubricity lost in ultra-low sulfur diesel.

She gave an overview of the wide range of feedstock available for biodiesel processing, and spoke about the three D’s of waste feedstock: the diverse array, distributed concentration and diluted fatty acid content. The said fats oils and greases in sewage waste water for instance is as low as 35 parts per million since most of it is water and solids.

Borgese said her company uses a controlled algorithm to control an intensified heat method to put the heat where it’s needed in feedstock pretreatment. This is a cost-saver, she said, because conventional plants use tanks with heated coils on the bottom to keep the sludge soluble, costing 3.5 cents a gallon in heating costs, which is relatively expensive. Borgese also spoke about using liquid-liquid extraction with finished biodiesel to help pull the FOG out of the diluted waste feedstock. PreProcess Inc. is also working on an in situ super critical extraction method.

Frank Yeboah with North Carolina A&T University discussed his department of defense project looking at the impact of taking all the military waste vegetable oil for conversion to biodiesel. He said if DOD was a country, its fuel consumption would rank 34 in the world, a testament to how much fuel our military operations use. He mentioned a project in Guantanamo Bay where they took the 1,500 gallons of WVO produced monthly and, using a 40-gallon batch process, converted the waste to biodiesel. The project hopes to find exactly how much WVO is produced on military bases and barracks around the country and what beneficial impacts that would have if converted to biodiesel. He said thus far nothing much is done at all with the waste oils produced by DOD.

Brandon Spence, cofounder and CEO of Midlands Biofuels in South Carolina, a community-scale biodiesel plant, said Midlands Biofuels is the only ASTM-certified biodiesel production facility in the state. He and his team also started the first green apprenticeship in South Carolina. He said his company provides a service to the local food service industry that they are already paying for. “People like the local service,” he said. Regarding the lapse of the $1 per gallon blenders credit, Spence said, “We collect our own feedstock and we stand on our own two feet, we don’t need the dollar. In order for this business to survive, we can’t do it with subsidies.” He also said Midlands Biofuels is looking into solar applications for their process. Already the plant uses a lot of low heat, and does not use a centrifuge for dewatering. Midlands Biofuels also uses woody biomass for filtration, but one issue with that is the premature exhaustion of the wood chips. The company also runs its process on boilerless technology. This began by taking apart a tankless hot water heater, and having TDRA look at the engineering possibilities for using it to provide process heat. The plant uses two modified tankless hot water heaters to preheat the feedstock to 198 degrees in a 4,000 gallon tank with two-inch heating coils. “It cost us only $400 for our heating system,” Spence said.

The final speaker was Klaus Ruhmer, BDI BioEnergy International’s North American business development manager. He spoke on RepCat, a process developed by BDI to process high free fatty acid feedstock. RepCat does esterification and transesterification in one step. “It’s not quite super critical but it’s elevated temperatures and pressures for conversion of lower grade high FFA feedstock,” Ruhmer said. He also says quality has still got to remain a number one priority for producers, and one of the biggest jumps in technology to improve quality has been distillation. “In order to achieve profitability, quality must be the foundation, no shortcuts.” he said. “The most important pillar after that is yield. You can’t run on 80 to 85 percent yield.” Other necessities to make a biodiesel business profitable, he said, include having to sell high volumes of fuel as a commodity that’s competitively priced with diesel fuel, as well as being feedstock flexible.

“The subsidy was great for producers, but bad for investors,” Ruhmer said. “Because they would never know if it was going to go away.”

If feedstock prices change 5 percent, that can have a 40 percent impact on profit, he said. A 5 percent change in the price of biodiesel, or in the yield, can have a 50 percent impact on profitability. “For a 30 MMgy plant, a 1 percent loss in yield can cost $1 million.”