by Jim Lane (Biofuels Digest) It’s a capex figure so low that it sounds like a decimal point is missing. Though early-stage and just developing data out of its pilot — it’s well worth seeing what Sustainable Ethanol Technologies is up to, in its aim to drive down the capital costs of extracting cellulosic sugars from biomass.
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Systems usually run into the millions, even at small-scale, for the front end saccharification — that biomass just doesn’t want to give up its sugars, it’s worse than prizing a winning lottery ticket out of someone’s hand. So, it’s costly.
“Our advantage is low cost,” says CEO Julie Goodliffe, whose startup out of UNC Charlotte received the first strategic corporate partnership award from the Charlotte Venture Challenge for their patent-pending process to produce cellulosic ethanol from any kind of biomass.
“Nature has solved the problem of breakdown, our fungi grow through the biomass, and the fungi can degrade the lignin and then get to the sugars.”
How does it work? “We allow our fungi to grow on biomass, then breakdown the living system in a pile of woodchips or stover. We allow them to do it for 45 days, then mechanically grind. No acids or enzymes.”
Why so low-cost? “We don’t need a stainless steel tank, a concrete slab will do,” Goodliffe added. ” We don’t need lots of water, nor do we have hazardous chemicals in the process.”
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And, we haven’t been using autoclaves or other systems that wouldn’t be used in the field. We’ve used barrels, very dirty, with biomass from MSW at the EcoComplex and tipped yard waste. We innoculated it with fungi, left it, then grind it via a hammer mill, and tipped into a fermentation tank, then distilled it and got ethanol.
The yields? “We can convert 14% of woody biomass into sugars,” Goodliffe said. So, that translates into something like 40 gallons per ton, which is low. “we’ll need more time and funding to optimize the process, and validate at scale.”
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“The fungi are going to eat a little bit, so we use whiterot fungi to eat through lignin, that’s 30 days. Then we use then the brown rot for 15 days to get through to the sugars. We stop there because otherwise they will eat the sugar.”
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But well suited to the concept of extracting the sugars locally, right on the farm — think about transporting 280 pounds of sugars instead of a ton of biomass, from either on-farm operations, or local sugar extraction locations.
How much can the process be optimized, what mixes of sugars (e.g. C5, C6) can be obtained, hoe are adverse weather conditions tolerated, how much water in the biomass can be tolerated — these are questions that need to be answered. READ MORE