cellulose where rice hulls lie awaiting—pending a deal-closer. Straw, hulls or both projects concurrently, Yancey says BBI has a timeline in place to move either site forward by completing specified tasks in 2008.
Be Practical and Forward “We have all of 2008 to demonstrate the technology and generate the data we need to do the process design,” Yancey says. “Then we have all of 2009 to do detailed design work and build the plant.” The plan isn’t linear so several different tasks will be going on at once, but Yancey says BBI’s practical approach and project development experience will make this project go. “When we first talked, we sat down with them and said we still feel there are some technology gaps [for converting most biomass feedstocks to ethanol],” Yancey explains. “We told them our approach would circumvent those gaps and eliminate the missing technology.” The technology gaps Yancey refers to stem from CBEC’s desire to double-pretreat its feedstock before fermentation. The “pre-pretreatment” would liberate hemicellulose so its five-carbon sugars could carry on to fermentation. But, Yancey says, “pretreatment is still very expensive and an issue for any tech provider trying to use the fermentation route. Dilute acid requires expensive alloys or glass-lined or acid brick-lined equipment, and these primary pretreatments are generally done at a higher temperature, running up operational costs.” Furthermore, there are no commercially demonstrated organisms capable of proficiently fermenting fivecarbon sugars, so even if the uncertainty and expense of pretreatment were endured Yancey says exactly how those sugars would be fermented is still questionable. If it becomes feasible to isolate and ferment the five-carbon sugars from rice waste in the future, then a move in that direction could be made. Until then, BBI suggested moving forward with a base pretreatment that dissolves the silica.
A Series of Concurrent Events BBI’s forward approach hooked Bowers from the start. “What you get from BBI is a sense of well-roundedness, and that their feet are on the ground,” Bowers says. “After our first meeting with BBI, I told my guys as we walked onto the airplane, ‘This is it. As far as I’m concerned let’s not look anyplace else so let’s make the best deal we can with them.’” The responsibilities BBI will undertake first include conducting a detailed study to define acceptable ranges of the key process variables. At press time in late December, the study had already begun. The financials of the first plant will be driven by established targets for these key process variables. For instance, the initial study may not reveal that the C6 yield will be 85 percent and, from that, “X”
amount of ethanol will be refined. “What it will tell us is that we will need at least 70 percent, for example, and if we can’t reach that established target then we know we can’t do this,” Yancey says. Essentially, the purpose of BBI’s initial study is to determine what is needed to make the project competitive, and is expected to be complete by the end of February. By then, BBI plans to have already begun developing what Yancey calls a technology demonstration plan. “That’s where we’ll generate the data needed to design the plant,” he says. Bench- and pilot-scale work managed by BBI will continue throughout most of 2008. As data streams in, BBI will take the aggressive initiative to concurrently develop the “Schedule A” basic engineering package to transfer knowledge from
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