Acute View Transport biofuels: Can they help limiting climate change without an upward impact on food prices?

Comprehensive life cycle assessments show that current transport biofuels often do worse than conventional fossil transport fuels as to the emission of greenhouse gases. Biofuels from microalgae grown with present technology and lignocellulosic biofuels from current arable land or land that is to be deforested are unlikely to do better regarding the emission of greenhouse gases than fossil transport fuels. When crops characterized by relatively low fossil fuel inputs and relatively high biomass yields are grown on abandoned agricultural and marginal soils which currently sequester little carbon, cropping for transport biofuels may help in limiting climate change without an impact on food prices. For such cropping one probably has to go beyond the market mechanism. Worldwide, there is some scope for the use of harvest residues in biofuel production. However, European arable soils show on average large losses of soil carbon and this rather favors increased addition of such residues to soils. Received: November 17, 2008; accepted: December 3, 2008     

负载型Co基双功能催化剂上戊酸酯生物燃料的制备

采用浸渍法制备了HZSM-5、HY、Hβ以及MCM-22四种载体上负载Co的催化剂,在高压反应釜中,开展了以乙酰丙酸乙酯为原料一步法加氢脱氧合成戊酸乙酯以及戊酸生物燃料的研究。采用XRD、XPS、TEM、FT-IR、NH₃-TPD、H₂-TPR、py-FTIR、ICP-AES等对催化剂进行表征。结果表明,10Co/HZSM-5催化剂由于Co在HZSM-5上分布均匀,并且B酸酸性、总酸量以及还原性能最优,在保持较高的反应性能的同时,提高了产物的选择性,具有较高的催化性能。进一步对反应温度、反应压力等进行优化,在反应温度为240℃、压力为3 MPa、反应3 h时,以正辛烷作溶剂,催化剂表现出较高的催化性能,乙酰丙酸乙酯的转化率达到100%,戊酸酯和戊酸的总收率可达90%。     

Hydrophobic mesoporous acidic resin for hydroxyalkylation/alkylation of 2‐methylfuran and ketone to high‐density biofuel

Hydroxyalkylation/alkylation of biomass‐derived 2‐methylfuran with cyclic ketones (cyclopentanone and cyclohexanone) has great potential in synthesizing high‐density biofuel. But the conversion and selectivity are still unsatisfactory because the in‐situ formed water decreases the acidity of catalyst and induces side reaction. Herein, hydrophobic mesoporous resins with sulfonic acid group (PS) and fluoride sulfonic acid group (PCS) were synthesized by a simple solvothermal reaction and ion exchange treatment, which have good mesoporous structure with surface area of 300–700 m²/g. Notably, PS and PCS have better hydrophobicity and oleophilicity as compared to widely used sulfonic acid functional amberlyst‐15 and fluoride sulfonic acid functional nafion‐212. In the hydroxyalkylation/alkylation reaction, PS shows higher activity and selectivity than amberlyst‐15 while PCS surpasses nafion‐212. Furthermore, both PS and PCS have good recycling stability in consecutive 5 runs. After hydrodeoxygenation, two high‐density biofuels with density of 0.819 and 0.825 g/mL were obtained. © 2016 American Institute of Chemical Engineers AIChE J, 63: 680–688, 2017     

一种有潜力的生物燃料原料——秸秆

秸秆是一种用作生物燃料、具有潜力的原料,如玉米秸秆、大麦秸秆、小麦秸秆、细条芦笋和稻谷秸秆等.阐述了美国能源部重点开发高效发酵微生物,把生物质原料转化成乙醇的5项乙醇转化项目,该项目预计用3年时间完成,投资约2330万美元.介绍了美国能源部投资12亿美元,在6家生物炼制厂用4年时间,每年生产4.92亿L纤维素乙醇的计划.     

生物燃料在我国公路交通中替代潜力分析

首先从我国生物燃料开发的资源保障性、生产的技术经济性以及现代汽车技术利用的可能性等方面,对生物燃料的开发利用潜力进行了分析。之后重点论述了利用IPAC模型研究我国未来公路交通能源需求以及生物燃料替代的发展情景。研究表明:未来我国公路交通倍增的油品需求对我国石油供应造成巨大压力,推广新型汽车技术和发展替代燃料是降低公路交通油品消耗的战略措施,混合动力汽车技术与生物燃料结合是我国未来公路交通最佳的技术选择,并且生物燃料在我国未来公路交通中将展现出很强的燃料替代前景。     

Biodiesel Production from Waste Cooking Oil by Enzymatic Catalysis Process

Biodiesel is an excellent option for reducing dependence on fossil fuels with environmental advantages by reducing hazardous emissions. The enzymatic transesterification has attracted the attention of researchers in the last decade and the advantages of enzymatic catalysis show that the production of biodiesel by this route has good potential, mainly because it is friendly environment. For biodiesel, production process by enzyme catalysis is chosen the response surface methodology. It is an experimental strategy to find the best operating conditions oftransesterification reaction to improve the biodiesel quality. The Process has three variables： temperature, molar ratio oil-alcohol and catalyst quantity. The process was monitored by GC-FID （gas chromatography with flame ionization detector）. The yield of the transesterification reaction by enzymatic catalysis decreases with increasing temperature, and may be due to inactivation of the enzyme by denaturation at temperatures above 50 ℃. The second-order design used was the ＂CDC （central design composition）＂ which produced a maximum yield of 95.5% in the transesterification reaction by enzymatic catalysis obtained at a temperature of 45 ℃, molar ratio methanol：oil of 8：1 and a catalyst loading of 8% wt.     

Immobilization of Trametes hirsuta laccase into poly(3,4-ethylenedioxythiophene) and polyaniline polymer-matrices

The immobilization of Trametes hirsuta laccase (ThL) in the poly(3,4-ethylenedioxythiophene) (PEDOT) and polyaniline (PANI) matrices was carried out in order to study the catalytic effect of ThL in different biocathode structures in a biofuel cell application. By using 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS) as a mediator compound, the immobilized ThL in both polymer matrices, exhibited catalytic activity for the reduction of oxygen into water. The amount of ThL was adjustable in the PEDOT matrix by controlling the working parameters, such as the charge density used in the electropolymerization of EDOT monomer and the ThL concentration used in the electropolymerization electrolyte. In the PEDOT biocathode structure, the utilization of porous material as the PEDOT supporting template was studied in order to improve the current density generated per unit area/volume. Reticulated vitreous carbon foam (RVC foam) was chosen as the PEDOT supporting template material and the biocathodes were manufactured by in situ entrapment of ThL into PEDOT films polymerized on the RVC foam. These biocathodes possessed a high cathodic open circuit potential and produced a large current density, reaching 1 mA cm⁻³ at 0.45 V when 19.5 μg ml⁻¹ of ThL was used in the electrolyte. The performance of these biocathodes was extremely sensitive to variations in pH and the optimal working pH was around 4.2. The biocathode reserved 80%, 50%, and 30% of the catalytic activity after storage in a +4 °C buffer solution for 1 day, 1 week, and 1 month, respectively. The PANI matrix was prepared in a form of printable ink where ThL was in situ entrapped in the PANI matrix during the laccase activated polymerization of aniline using a chemical batch reactor method. Different amounts of the ThL-containing printable PANI ink were then applied on carbon paper and the performance of the ink was subsequently electrochemically characterized. In this way, not only two different polymer matrices, but also two different matrix manufacturing procedures could be compared.     

在石油为主要能源的世界中发展乙醇生产——巴西乙醇生产的经验

当前,人们生活在依赖石油的世界中,因为汽油和柴油的价格不断升高,许多国家都在寻求化石燃油的替代物。用糖类作物或谷物生产的乙醇被视为最好的替代物。然而,全球目前乙醇产量仅为汽油耗量的2．5％,所以乙醇需求增长迅速,市场广阔。介绍了巴西乙醇生产的经验;在乙醇市场波动的情况下,乙醇生产商得以生存的措施;乙醇生产商的生产方式;乙醇生产所用糖浆原料的概况等。     

Algal capture of carbon dioxide; biomass generation as a tool for greenhouse gas mitigation with reference to New Zealand energy strategy and policy

The use of algae to capture carbon dioxide as a method for greenhouse gas mitigation is discussed. A small fraction of the sunlight energy that bathes Earth is captured by photosynthesis and drives most living systems. Life on Earth is carbon-based and the energy is used to fix atmospheric carbon dioxide into biological material (biomass), indeed fossil fuels that we consume today are a legacy of mostly algal photosynthesis. Algae can be thought of as marine and freshwater plants that have higher photosynthetic efficiencies than terrestrial plants and are more efficient capturing carbon (Box 1). They have other favourable characteristics for this purpose. In the context of New Zealand energy strategy and policy I discuss progress in growing algae and seaweeds with emphasis on their application for exhaust flue carbon recycling for possible generation of useful biomass. I also introduce schemes utilising wild oceanic algae for carbon dioxide sequestration and the merits and possible adverse effects of using this approach. This paper is designed as an approachable review of the science and technology for policy makers and a summary of the New Zealand policy environment for those wishing to deploy biological carbon sequestration.