The Control of Lactobacillus sp.by Extracellular Compound Produced by Pseudomonas aeruginosa in the Fermentation Process of Fuel Ethanol Industry in Brazil

This work evaluated the effect of secondary bacterial metabolites produced by Pseudomonas sp LV strain in control of Lactobacillus sp. population in the microcosm of the vat during ethanol fermentation. The fraction F4 produced by Pseudomonas aeruginosa was extracted with dichloromethane and fractionating by vacuum liquid chromatography obtained in a methanol phase. The evaluation of antibiotic activity of F4 fraction mixed or not with sulphuric acid and Kamoram?. The antibiotic activity of F4 fraction was determined as well as the fermentation efficiency. Also was determined yeast cell viability, budding formation, the viability of budding cells, and number of populations of Saccharomyces cerevisiae and Lactobacillus sp. The results showed that the F4 fraction had high selective antibiotic activity against Lactobacillus sp. but not for S. cerevisae, and no inhibitory effect was observed in the fermentation process by yeast. Also F4 fraction decreased flocculation and foam formation. The F4 has an antibiotic activity against Lactobacillus sp. and should be used as an alternative to control bacteria contamination and foam and flocculation formation in the fuel ethanol fermentation process. The F4 fraction could reduce the use of antibiotics in the control of Lactobacillus sp. population during the fuel ethanol production.

Sorghum as Dry Land Feedstock for Fuel Ethanol Production

Dry land crops such as sorghums (grain sorghum, sweet sorghum and forage sorghum) have been identified as promising feedstocks for fuel ethanol production. The major issue for using the sweet sorghum as feedstock is its stability at room temperature. At room temperature, the sweet sorghum juice could lose from 40% to 50% of its fermentable sugars from 7 to 14 days. No significant sugar content and profile changes were observed in juice stored at refrigerator temperature in two weeks. Ethanol fermentation efficiencies of fresh and frozen juice were high (～93%). Concentrated juice (≥25% sugar) had significantly lower efficiencies and large amounts of fructose left in finished beer; however, winery yeast strains and novel fermentation techniques may solve these problems. The ethanol yield from sorghum grain increased as starch content increased. No linear relationship between starch content and fermentation efficiency was found. Key factors affecting the ethanol fermentation efficiency of sorghum include starches and protein digestibility, amylose-lipid complexes, tannin content, and mash viscosity. Life cycle analysis showed a positive net energy value (NEV) = 25 500 Btu/gal ethanol. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were used to determine changes in the structure and chemical composition of sorghum biomasses. Dilute sulfuric acid pretreatment was effective in removing the hemicellulose from biomasses and exposing the cellulose for enzymatic hydrolysis. Forage sorghum lignin had a lower syringyl/guaiacyl ratio and its pretreated biomass was easier to hydrolyze. Up to 72% hexose yield and 94% pentose yield were obtained by using a modified steam explosion with 2% sulfuric acid at 140℃ for 30 min and enzymatic hydrolysis with cellulase.

Hainan to invest 350 million Yuan in fuel ethanol projects

Hainan Yedao (Group) Co. Ltd. plans to invest 350 million Yuan in construction of a fuel ethanol project. With cooperation of a large state-owned petrochemical enter- prise, this project is planned to produce 100 thousand

Simulation of Fuel Ethanol Production from Lignocellulosic Biomass

Models for hydrolysis,fermentation and concentration process,production and utilization of biogas as well as lignin gasification are developed to calculate the heat demand of ethanol production process and the amounts of heat and power generated from residues and wastewater of the process.For the energy analysis,all relevant information about the process streams,physical properties,and mass and energy balances are considered.Energy integration is investigated for establishing a network of facilities for heat and power generation from wastewater and residues treatment aiming at the increase of energy efficiency.Feeding the lignin to an IGCC process,the electric efficiency is increased by 4.4% compared with combustion,which leads to an overall energy efficiency of 53.8%.A detailed sensitivity analysis on energy efficiency is also carried out.

Allocation of Energy Use in the Biomass-based Fuel Ethanol System and Its Use in Decision Making

The Chinese government is developing biomass ethanol as one of its automobile fuels for energy security and environmental improvement reasons. The energy efficiency of the biomass-based fuel ethanol is critical issue. To investigate the energy use in the three biomass-base ethanol fuel systems, energy content approach, Market value approach and Product displacement approach methods were used to allocate the energy use based on life cycle energy assessment. The results shows that the net energy of corn based, wheat based, and cassava-based ethanol fuel are 12543MJ, 10299MJ and 13112MJ when get one ton biomassbased ethanol, respectively, and they do produce positive net energy.

Preparation and emission characteristics of ethanol-diesel fuel blends

The preparation of ethanol-diesel fuel blends and their emission characteristics were investigated. Results showed the absolute ethanol can dissolve in diesel fuel at an arbitrary ratio and a small quantity of water(0.2%) addition can lead to the phase separation of blends. An organic additive was synthesized and it can develop the ability of resistance to water and maintain the stability of ethanol-diesel-trace amounts of water system. The emission characteristics of 10%, 20%, and 30% ethanol-diesel fuel blends, with or without additives, were compared with those of diesel fuel in a direct injection(DI) diesel engine. The experimental results indicated that the blend of ethanol with diesel fuel significantly reduced the concentrations of smoke, hydrocarbon(HC), and carbon monoxide(CO) in exhaust gas. Using 20% ethanol-diesel fuel blend with the additive of 2% of the total volume, the optimum mixing ratio was achieved, at which the bench diesel engine testing showed a significant decrease in exhaust gas. Bosch smoke number was reduced by 55%, HC emission by 70%, and CO emission by 45%, at 13 kW/1540 r/min. However, ethanol-diesel fuel blends produced a few ppm acetaldehydes and more ethanol in exhaust gas.

A Novel Routine for Manufacture of Environmentally Friendly Ethanol Fuel via Reactive Distillation

A novel routine for removing water from ethanol by the hydration using C4 olefin cut catalyzed with the ion exchange resin was proposed. Reactive distillation experiments were carried out to demonstrate the feasibility of this routine. The sensitivity analysis was performed by using the software of ASPEN PLUS 10.2. The optimized operating conditions were obtained considering three objective functions which were the water content of the bottom product, water conversion rate and hydration selectivity. Under the optimized operation conditions, the final product was consisted of 45.0% of ethanol, 19.4% of ethyl tert-butyl ether, 35.1% of tert-butyl alcohol and 0.6% of water in volumetric percentage.

Preparation and characterization of Pt-WO_3/C catalysts for direct ethanol fuel cells

Three co-impregnation/chemical reduction methods in acidic solutions of pH < 1,including ethylene glycol (EG),NaBH4,and HCOOH,were compared for Pt-WO3/C catalysts.Pt-WO3/C catalysts containing 10 wt.% and 20 wt.% platinum per carbon were prepared by the three methods;their morphology and electrocatalytic activities were characterized.The 20 wt.% Pt-WO3/C catalyst prepared by the co-impregnation/EG method presented the optimal dispersion with an average particle size of 4.6 nm and subsequently the best electrocatalytic activity,and so,it was further characterized.Its anodic peak current density for ethanol oxidation from linear sweep voltammetry (LSV) is 7.9 mA·cm?2,which is 1.4 and 5.2 times as high as those of the catalysts prepared by co-impregnation/NaBH4 and co-impregnation/ HCOOH reduction methods,2.1 times as high as that of the 10 wt.% Pt-WO3/C catalyst prepared by co-impregnation/EG method,respectively.

Decision-making of biomass ethanol fuel policy based on life cycle 3E assessment

To evaluate the environmental, economic, energy performance of biomass ethanol fuel in China and to support the decision-making of biomass ethanol energy policy, an assessment method of life cycle 3E (economy, environment, energy) was applied to the three biomass ethanol fuel cycle alternatives, which includes cassava-based, corn-based and wheat-based ethanol fuel. The assessments provide a comparison of the economical performance, energy efficiency and environmental impacts of the three alternatives. And the development potential of the three alternatives in China was examined. The results are very useful for the Chinese government to make decisions on the biomass ethanol energy policy, and some advises for the decision-making of Chinese government were given.

Miscibility of Ethanol in Diesel Fuels

The primary barrier to the use of ethanol in diesel fuel is the poor miscibility at lower temperatures. The miscibilities of ethanol in 19 diesel fuels having a wide variation in compositions were evaluated by testing their phase separation temperatures. The result shows that aromatic contents and intermediate distillate temperatures have a significant impact on miscibility limits. The FCC diesels, which contain up to 50% of aromatics, exhibit different phase behavior trends in comparison with straight-run diesels and other diesel fuels.

Uncertainty in life cycle economical analysis of cassava-based ethanol fuel

Biomass ethanol fuel is not only renewable but also environmental-friendly. Guangxi Zhuang Autonomous Region is developing the cassava-based ethanol fuel. Economical performance of the project is the key issue. The traditional life cycle economical analysis is just a static calculation process. Uncertainty is the character of cassava yield, cost of cassava plant, cassava price, tax rate and gasoline price, and the economical performance of the project is determined by these aspects. This study proposes an economical model of cassava-based ethanol fuel. The method of Monte Carol is used to simulate the economical performance. This method conquers the shortage of the traditional way. The results show that cassava-based ethanol fuel can get survived when the tax is exempted. Finally, the study also evaluates the potential of the economical performance.

Synthesis and characterization of Pt-MoO_x-TiO_2 electrodes for direct ethanol fuel cells

To enhance the CO-tolerance performance of anode catalysts for direct ethanol fuel cells,carbon nanotubes were modified by titanium dioxide (donated as CNTs@TiO2) and subsequently served as the support for the preparation of Pt/CNTs@TiO2 and Pt-Mo/CNTs@TiO2 electrocatalysts via a UV-photoreduction method.The physicochemical characterizations of the catalysts were carried out by using X-ray diffraction (XRD),transmission electron microscopy (TEM),X-ray photoelectron spectroscopy (XPS),and infrared spectroscopy of adsorbed probe ammonia molecules.The electrocatalytic properties of the catalysts for methanol oxidation were investigated by the cyclic voltammetry technique.The results show that Pt-Mo/CNTs@TiO2 electrode exhibits the highest performance in all the electrodes.It is explained that,the structure,the oxidation states,and the acid-base properties of the catalysts are influenced due to the strong interaction between Ti and Mo species by adding TiO2 and MoOx to the Pt-based catalysts.

典型生物质发酵制取燃料乙醇环境影响分析

结合生命周期评价方法与层次分析方法对杨木、玉米秸秆、甘蔗渣3种典型纤维素生物质的发酵制取燃料乙醇工艺进行环境影响评价。针对酸化、富营养化、全球变暖、化石能源消耗、光化学污染、人体毒性6种环境类型进行分析对比,并选取3个不同视角分析生物质发酵工艺所带来的环境影响。结果表明:农业阶段和生产阶段所产生的温室效应在全生命周期过程中占比最高;全球性视角下,全球变暖影响占比较高;区域性和局地性视角下,工艺的酸化影响最严重。

燃料乙醇炼制系统优化与碳减排研究进展

生物质是丰富可再生的碳源,以糖、淀粉、秸秆纤维素或其他生物质原料高效生产燃料乙醇,可减少化石能源的需求,其中以木质纤维素为原料的第二代燃料乙醇具有广阔的发展前景。与化石能源相比,燃料乙醇具有环保、经济、可再生的优势,但其在生产工艺技术、经济效益和环境影响等方面仍需要深入研究。近年来,通过开展燃料乙醇炼制系统优化及全生命周期分析研究,有力地促进了燃料乙醇技术进步,推动了燃料乙醇碳减排相关研究。文章主要论述了近年来燃料乙醇生产技术的发展,重点对燃料乙醇系统的模拟优化和碳减排研究进展进行了总结,并对燃料乙醇发展趋势进行了展望,以期为燃料乙醇的可持续发展提供参考。

乙醇喷雾/氨气/甲烷三元燃料的燃烧特性

采用旋流喷雾燃烧器,通过分析燃烧时的火焰结构、OH^(*)和NH_(2)^(*)的荧光信号、火焰光谱以及污染物排放,探究了甲烷、乙醇和氨气3种燃料在不同当量比、摩尔分数和不同雾化空燃比(ALR)下对燃烧的影响和燃烧后烟气中NO、NO_(2)、CO含量的变化趋势。虽然氨气的使用会产生高氮氧化物的排放,但采用三元燃料掺混燃烧(特别是在乙醇占比较高)时,CO和NO的排放量相对较低,燃烧效果最佳。在0.45~0.70当量比范围内,提高ALR有助于喷雾雾化以产生更小的液滴粒径,促进液雾和气体的混合及燃烧,从而降低CO排放。通过三元燃料掺混对燃料的改性,以及燃烧工况的调控作为氨燃烧组织优化的手段,对工业上高效使用氨燃料和减少污染物排放具有指导意义。

High temperature polymer electrolyte membrane fuel cell

One of the majorissuesli mitingtheintroduction of polymer electrolyte membranefuel cells(PEMFCs) is thelowtemperature ofoperation which makes platinum-based anode catalysts susceptible to poisoning by the trace amount of CO,inevitably present in reformedfuel.In order to alleviate the problemof COpoisoning andi mprove the power density of the cell,operating at temperature above 100 ℃ispreferred.Nafion-type perfluorosulfonated polymers have been typically used for PEMFC.However,the conductivity of Nafion-typepolymers is not high enoughto be usedfor fuel cell operations at higher temperature(>90 ℃) and atmospheric pressure because they dehy-drate under these condition.An additional problem which faces the introduction of PEMFCtechnology is that of supplying or storing hydrogen for cell operation,especially for vehicular applications.Consequently the use of alternative fuels such as methanol and ethanol is of interest,especially if thiscan be used directlyinthe fuel cell,without reformationto hydrogen.Ali mitation of the direct use of alcohol is thelower activity of oxida-tionin comparison to hydrogen,which means that power densities are considerably lower.Hence to i mprove activity and power outputhigher temperatures of operation are preferable.To achieve this goal,requires a newpolymer electrolyte membrane which exhibits stabilityand high conductivityin the absence of liquid water.Experi mental data on a polybenzi midazole based PEMFC were presented.Asi mple steady-stateisothermal model of the fuel cell is alsoused to aidin fuel cell performance opti misation.The governing equations involve the coupling of kinetic,ohmic and mass transport.Thispaper also considers the advances madeinthe performance of direct methanol and solid polymer electrolyte fuel cells and considers theirli mi-tations in relation to the source and type of fuels to be used.

NOx Emission Reduction Using Hydrous Ethanol-Gasoline Blend with Syngas in SI Engine

This paper presents a comparatively experimental study of nitrogen oxide (NOx) emissions from an internal combustion engine fed by gasoline available in the Saudi Arabian market rating octane number (RON 91 and RON 95) with admixtures of syngas with 0% E0, 5% E5 and 10% E10—by volume of pure ethanol—and HE5 and HE10 with water concentrations of 5%, 10%, 30% and 40%—by volume of hydrous ethanol—at stoichio-metric mixtures. An on-board plasma system used to produce syngas through the partial oxidation of gasoline with air in a plasma-assisted fuel reformer. The syngas injected in a gasoline engine with a fuel injection system modified for operation with addition of some amount of syngas. The experimental results demonstrated a significant total reduction in NOx emissions and slightly increased in fuel consumption when mixing gasoline (RON 91 and RON 95), ethanol (E5 and E10) and hydrous ethanol (HE5 and HE10) with syngas. For the use of hydrous ethanol (HE5 and HE10) along with the addition of syngas, for both RON 91 and RON 95, the lowest NOx emissions are found 72% with a water concentration of 40%.