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Boulder City, CO, United States

Agency: Cordis | Branch: FP7 | Program: CP-IP | Phase: KBBE-2007-3-3-02 | Award Amount: 7.36M | Year: 2008

BACSIN is a 16-member consortium with the main focus to improve rational exploitation of the catalytic properties of bacteria for the treatment and prevention of environmental pollution. Current application of bacteria in the environment is hindered by the lack of knowledge on the effects of stresses on cellular activity, most importantly abiotic stresses prevailing on site (e.g., desiccation or nutrient starvation), stresses as a result of pollution itself (e.g., toxicity), and those during strain preparation and formulation. BACSIN proposes four iterative poles of research and technology to overcome this hindrance for subsequent improved microbial usage. The 1st pole will investigate genome-wide catabolic and stress expression in a set of different pollutant degrading bacteria (the BACSINs). Key cellular factors and regulatory networks determining the interplay between stress-survival and pollutant catabolism will be unveiled, and faithful predictive models for cell behaviour produced. The 2nd pole will study stress resistance, survival and activity of BACSINs in real polluted environments, via microcosms and in situ traps, plant roots and leaves, while accentuating possible effects on native communities. The 3d pole will focus on the original microbial communities at contaminated sites, to discover and exploit more optimal stress and survival resistance among resident pollutant-degrading bacteria. We will develop molecular diagnostics tools to screen contaminated sites for catabolic and stress parameters, and decide whether BACSIN complementation should be considered. Promising isolates of resident bacteria will be studied as new BACSINs, to show the usefulness of the diagnosis-isolation-reintroduction approach for enhancing pollutant biodegradation rates. Finally, we will focus on BACSIN formulations, to understand the stresses on bacteria during growth, preservation and resuscitation, and to produce optimally active cells for environmental application.

Christensen E.,National Renewable Energy Laboratory | Yanowitz J.,Ecoengineering Inc. | Ratcliff M.,National Renewable Energy Laboratory | McCormick R.L.,National Renewable Energy Laboratory
Energy and Fuels | Year: 2011

The oxygenates ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol (isobutanol), 1-pentanol, 3-methyl-1-butanol (isopentanol), methyl levulinate, ethyl levulinate, butyl levulinate, 2-methyltetrahydrofuran (MTHF), 2-methylfuran (MF), and 2,5-dimethylfuran (DMF) were blended in three gasoline blendstocks for oxygenate blending (BOBs) at levels up to 3.7 wt % oxygen. Chemical and physical properties of the blends were compared to the requirements of ASTM specification D4814 for spark-ignited engine fuels to determine their utility as gasoline extenders. Vapor pressure, vapor lock protection, distillation, density, octane rating, viscosity, and potential for extraction into water were measured. Blending of ethanol at 3.7% oxygen increased vapor pressure by 5-7 kPa as expected. 2-Propanol slightly increased vapor pressure in the lowest-volatility BOB, while all other oxygenates caused a reduction in vapor pressure of up to 10 kPa. Coefficients for the Wilson equation were fitted to the measured vapor pressure data and were shown to adequately predict the vapor pressure of oxygenate-gasoline blends for five individual alcohols and MTHF in different gasolines. Higher alcohols and other oxygenates generally improved vapor lock protection. Butyl levulinate blended at 2.7% oxygen caused the distillation end point to exceed 225 °C, thus failing the specification. Distillation parameters were within specification limits for the other oxygenates tested. Other than ethanol, MF, and DMF, the oxygenates examined will not produce blends with satisfactory octane ratings at these blend levels when blended into lower-octane blendstocks designed for ethanol blending. However, all oxygenates tested except 1-pentanol and MTHF produced an increase in octane rating. For ethanol, the propanol isomers, and methyl levulinate, 20 wt % or more of the oxygenate could be extracted into water in a room-temperature water tolerance experiment. For the butanol isomers and ethyl levulinate, the percent extracted ranged from about 4% to 8%. Extraction for other oxygenates was 2% or lower. Methyl levulinate separates from gasoline as a separate liquid phase at temperatures below 0 °C. © 2011 American Chemical Society.

Alleman T.L.,National Renewable Energy Laboratory | McCormick R.L.,National Renewable Energy Laboratory | Yanowitz J.,Ecoengineering Inc.
Energy and Fuels | Year: 2015

This project looks at the potential of blending ethanol with natural gasoline to produce Flex-Fuels (ASTM D5798-13a) and high-octane, mid-level ethanol blends. Eight natural gasoline samples were collected from pipeline companies or ethanol producers around the United States. Analysis of the natural gasoline shows that the samples are 80-95% paraffinic, 5-15% naphthenic, 3% or less aromatics, and the balance olefins. The paraffins were typically pentane and isopentanes. The benzene content ranged from approximately 0.1 to 1.2 wt % such that blends of E30 or more would meet United States Environmental Protection Agency (U.S. EPA) limits for the benzene content in gasoline. The sulfur content in the natural gasoline ranged between 4 and 146 ppm. Assuming the lowest ethanol content in Flex-Fuel of 51 volume percent (vol %), a natural gasoline blendstock would be required to have 20 ppm sulfur or less for the finished fuel to meet the upcoming U.S. EPA Tier 3 gasoline sulfur limit. The research octane number (RON) (ASTM D2699-13) for the natural gasoline ranged from 67 to 72. Vapor pressure (ASTM D5191-13) ranged from 89 to 101 kPa. Two natural gasoline samples were selected for blending with ethanol. To make a 91 RON fuel (typical of U.S. regular gasoline), natural gasoline had to be blended with 30 vol % ethanol. Because of the high vapor pressure of these blendstocks, over 70 vol % ethanol could be blended into Flex-Fuel while still meeting the class 4 (wintertime) minimum vapor pressure requirement of 66 kPa. For blending of class 1 (summertime) Flex-Fuel, a minimum of 74 vol % ethanol was required to stay below the 62 kPa upper limit on vapor pressure. Modeling of vapor pressure using universal quasichemical functional-group activity coefficients (UNIFAC) and Wilson equation-based approaches provided good agreement with experimental data for most samples. © 2015 American Chemical Society.

McCormick R.L.,National Renewable Energy Laboratory | Ratcliff M.A.,National Renewable Energy Laboratory | Christensen E.,National Renewable Energy Laboratory | Fouts L.,National Renewable Energy Laboratory | And 5 more authors.
Energy and Fuels | Year: 2015

Oxygenates present in partially hydroprocessed lignocellulosic-biomass pyrolysis oils were examined for their impact on the performance properties of gasoline and diesel. These included: methyltetrahydrofuran, 2,5-dimethylfuran (DMF), 2-hexanone, 4-methylanisole, phenol, p-cresol, 2,4-xylenol, guaiacol, 4-methylguaiacol, 4-methylacetophenone, 4-propylphenol, and 4-propylguaiacol. Literature values indicate that acute toxicity for these compounds falls within the range of the components in petroleum-derived fuels. On the basis of the available data, 4-methylanisole and by extension other methyl aryl ethers appear to be the best drop-in fuel components for gasoline because they significantly increase research octane number and slightly reduce vapor pressure without significant negative fuel property effects. A significant finding is that DMF can produce high levels of gum under oxidizing conditions. If the poor stability results observed for DMF could be addressed with a stabilizer additive or removal of impurities, it could also be considered a strong drop-in fuel candidate. The low solubility of phenol and p-cresol (and by extension, the two other cresol isomers) in hydrocarbons and the observation that phenol is also highly extractable into water suggest that these molecules cannot likely be present above trace levels in drop-in fuels. The diesel boiling range oxygenates all have low cetane numbers, which presents challenges for blending into diesel fuel. There were some beneficial properties observed for the phenolic oxygenates in diesel, including increasing conductivity, lubricity, and oxidation stability of the diesel fuel. Oxygenates other than phenol and cresol, including other phenolic compounds, showed no negative impacts at the low blend levels examined here and could likely be present in an upgraded bio-oil gasoline or diesel blendstock at low levels to make a drop-in fuel. On the basis of solubility parameter theory, 4-methylanisole and DMF showed less interaction with elastomers than ethanol, while phenolic compounds showed somewhat greater interaction. This effect is not large, especially at low blend levels, and is also less significant as the size and number of alkyl substituents on the phenol ring increase. © 2015 American Chemical Society.

Ratcliff M.A.,U.S. Department of Energy | Luecke J.,U.S. Department of Energy | Williams A.,U.S. Department of Energy | Christensen E.,U.S. Department of Energy | And 3 more authors.
Environmental Science and Technology | Year: 2013

Certification gasoline was splash blended with alcohols to produce four blends: ethanol (16 vol%), n-butanol (17 vol%), i-butanol (21 vol%), and an i-butanol (12 vol%)/ethanol (7 vol%) mixture; these fuels were tested in a 2009 Honda Odyssey (a Tier 2 Bin 5 vehicle) over triplicate LA92 cycles. Emissions of oxides of nitrogen, carbon monoxide, non-methane organic gases (NMOG), unburned alcohols, carbonyls, and C1-C8 hydrocarbons (particularly 1,3-butadiene and benzene) were determined. Large, statistically significant fuel effects on regulated emissions were a 29% reduction in CO from E16 and a 60% increase in formaldehyde emissions from i-butanol, compared to certification gasoline. Ethanol produced the highest unburned alcohol emissions of 1.38 mg/mile ethanol, while butanols produced much lower unburned alcohol emissions (0.17 mg/mile n-butanol, and 0.30 mg/mile i-butanol); these reductions were offset by higher emissions of carbonyls. Formaldehyde, acetaldehyde, and butyraldehyde were the most significant carbonyls from the n-butanol blend, while formaldehyde, acetone, and 2-methylpropanal were the most significant from the i-butanol blend. The 12% i-butanol/7% ethanol blend was designed to produce no increase in gasoline vapor pressure. This fuel's exhaust emissions contained the lowest total oxygenates among the alcohol blends and the lowest NMOG of all fuels tested. © 2013 American Chemical Society.

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