Chemical Processing - February 2008 - (Page 11)

IN PROCESS >> >> 150% 120% 90% 60% 30% Environmental benefit Acrylic acid Acetic acid Lysine Caprolactam Adipic acid PHA -30% -60% -90% -120% Today-starch Today-cane Future-startch Succinic acid Lactic acid Future-ligno Future-cane Figure 1. Most bio-based routes provide reductions in greenhouse gas emissions. Source: Environmental Science & Technology. Responses (%) crude-oil price of $70/bbl for a slightly reduced number of bulk chemicals… The outlook can be summarized as ‘the picture improves’ — even at the highest sugar price of 400€/mt, ethanol, succinic acid, PDO/PTT, PLA and ethyl lactate are economically viable,” she notes. “At 200€/mt, the list also includes acetone/butanol/ethanol and ethylene.” The Utrecht University team now has evaluated economic viability, market size and environmental improvement together. “The results show that ethylene is best, followed by PHA, PLA and PTT (the latter three are on the same level). Market size is an important factor here, as the market for ethylene is very large, whereas the market may be much smaller for other chemicals.” Prospects for biofeedstock-based bulk chemicals are favorable but Hermann raises a caution: “We have seen a coupling of sugar and oil prices, with both prices increasing significantly in the past year.” Several factors have contributed to this, including recent crop failures, economic growth in China and India, and competition with biofuels, she explains. “There are ambitious policy goals [for biofuels], whereas policies for biochemicals are still missing… policy action by governments can lead to improvements for biochemicals,” she stresses. Ethylene PLA Ethanol PDO Butanol PTT EL 0% Isobutanol boasts a higher energy density and octane number than ethanol as well as lower hygroscopicity, notes James C. Liao, professor of chemical and biomolecular engineering at the school. However, bacteria ordinarily won’t synthesize higher alcohols like isobutanol. Liao and his team overcame this through genetic modification of E. coli — shunting intermediates from amino-acid biosynthesis pathways to alcohol production. This results in conversion of glucose with high specificity and at high yield to isobutanol. A reactor is seeded with the modified E. coli and glucose. Reaction over the next 40+ hours converts all the sugar into isobutanol and carbon dioxide, he notes. Yields, now 0.35 g of alcohol/g of sugar, already approach 90% of theoretical, without optimization of the bacteria and the process, says Liao. Gevo now is working on the optimizations. A 1,500–2,000 L/batch pilot plant should be operating within six months, says Gruber, adding that the process should be ready for commercialization by the end of 2009 or early 2010. The first installation likely will be a retrofit of a North American ethanol plant, he says. This involves using the new bacteria and adding a skid for product separation. Conversion of a 100-million-gal/yr plant should run about $20 million, Gruber reckons. Gevo also plans to offer another skid that will convert the isobutanol to materials comparable in makeup to conventional jet fuel and biodiesel. This will make economic sense at a crude oil price of $75/bbl, he says. Meanwhile, Liao is developing modified bacteria that would work on cellulose instead of glucose, and hopes to finish constructing the strains this year. CP What is the status of a Security Vulnerabililty Assessment at your site? 40 30 20 10 0 Have already Are Plan to Have no Don’t know conducted conducting conduct one plans to one one now shortly conduct one Isobutanol beckons as biofuel Genetically modified bacteria promise to provide a low-cost way to produce isobutanol from sugar — opening up the prospect of the alcohol displacing ethanol as a biofuel, say developers at the University of California, Los Angeles. The biobased route should halve the cost of making isobutanol, believes Pat Gruber, CEO of Gevo, Inc., Pasadena, Calif., which holds the exclusive license for the technology from UCLA. www.chemicalprocessing.com Assessment mandated by the Department of Homeland Security hasn't yet become routine at plants. To participate in this month’s poll, go to ChemicalProcessing.com. February 2008 • 11 http://www.chemicalprocessing.com http://www.chemicalprocessing.com

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Chemical Processing - February 2008 Contents From the Editor ChemicalProcessing.com Field Notes In Process Energy Saver Compliance Advisor Nanoparticle Safety Raises Questions Take the Pressure Off Vacuum Systems Achieve Optimum Centrifugal Pump Performance Rethink Batch-Manufacturing Alarm Systems Dr. Gooddata Orlando Plant Pioneers HMI Migration Strategy Process Puzzler Plant InSites Equipment & Services Ad Index Product Spotlight/Classifieds End Point

Chemical Processing - February 2008

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