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[en] To find a useful and environment-friendly fuel is difficult. Lead and benzene already were replaced by methyl tertiary butylether (MTBE), but this fuel additive too appears to be hazardous for man and the environment. When MTBE will be banned the chances for so-called green petrol (made from biomass) are rising. A brief overview of the developments in the field of fuel additives so far is given
[en] Compounds such as 2-ethylhexyl nitrate (2-EHN) are added to diesel fuel to improve ignition and boost cetane number. The production of 2-EHN reaches around 100000 tons per year in France, principally. Risks associated to its utilization are however poorly known because, in case of accidental release in the environment, nothing is known about its biodegradation. In this study, we aimed at (i) identifying bacterial strains able to degrade 2-EHN and compare their capabilities, (ii) elucidating the degradation pathway, and (iii) identifying the enzymes involved. Biodegradation of 2-EHN was first tested in biphasic cultures under conditions that reduce the toxicity and increase the availability of the hydrophobic substrate. Using optimized culture conditions, we showed that several strains of Mycobacterium austroafricanum were able to degrade 2-EHN. One of the most efficient strain (IFP 2173) which could grow at 2-EHN concentrations up to 6 g.L-1, was chosen to investigate the degradation pathway. On the basis of carbon balance determination and gas chromatographic (GC) analysis on the culture medium, I found that the degradation of 2-EHN was incomplete and gave rise to the accumulation of a metabolite. This metabolite was identified as β-methyl-γ-butyrolactone by GC-MS and LC-MS/MS analysis. The structure of the lactone indicated that 2-EHN was degraded through a pathway involving the hydroxylation of the methyl group of the main carbon chain, its oxidation into aldehyde an acid and a subsequent cycle of b-oxidation. Enzymes involved in the 2-EHN biodegradation pathway were looked for by a proteomic approach. Analyses by two-dimensional gel electrophoresis showed that, when exposed to 2-EHN, strain IFP 2173 triggered the synthesis of a bunch of enzymes specialized in fatty acid metabolism such as β-oxidation enzymes, as well as alcohol and aldehyde dehydrogenases. An exhaustive analysis of the IFP 2173 proteome resulted in the identification of more than 200 proteins induced on 2-EHN, including a cytochrome P450 predicted to function as an alkane monooxygenase (CYP153). Moreover, I also cloned genes encoding two transmembrane alkane hydroxylases, which passed undetected in the proteomic analysis. Hence, strain IFP 2173 syntheses three alkane hydroxylases potentially able to catalyze the initial attack on 2-EHN. In order to determine which of the three monooxygenase was responsible for this reaction, their structural gene was cloned in plasmids designed for the expression in either E. coli or M. smegmatis mc. Preliminary results indicated that the recombinant proteins were produced in some cases. These constructions will be used to separately study the activity of each enzyme with respect to alkane and 2-EHN hydroxylation. (author)
[en] The manganese-based MMT has been blended in gasoline fuel sold in Canada for almost 20 years. Invoking environmental health and consumer protection grounds, the federal government moved to prohibit the importation and inter-provincial trade of MMT in June 1997. Ethyl Corporation of Richmond, Virginia, the sole producers of MMT, claimed discriminatory treatment under NAFTA and sought $ 250 million in damages as compensation for alleged 'expropriation' of the company's investment interests. A stunning reversal of the Canadian government's decision occurred one year later. Canada agreed to pay Ethyl Corporation $ 13 million (representing legal fees and lost profits) and agreed to rescind the legislation and admit publicly that the use of MMT poses no environmental risk. The reversal was the result of the little-known Agreement on Internal Trade (AIT), a federal-provincial government agreement, intended to reduce 'non-tariff' barriers to inter-provincial trade and create greater economic union. The AIT is modelled on NAFTA and the Uruguay-round GATT, and treats relations between the Canadian provinces as if they were relations among sovereign states. In cases of conflict, provinces are entitled to seek resolution of complaints before dispute resolution panels. Some of the provinces voiced objection to the MMT legislation and Alberta, supported by three other provinces, filed an AIT complaint against the federal government for prohibiting the inter-provincial trade of MMT. The AIT dispute panel upheld Alberta's complaint. The decision was hailed as a 'triumph of principle over bad science'. It was an unmitigated success for Ethyl Corporation, and a humiliating defeat for the federal government. In this author's view, the MMT story is a clear example of yet another instrument by which corporate power can limit the capacity of democratically elected governments to act on behalf of the public good
[en] The paper discusses the reformulated gasoline market. After several years of discussions, negotiations, and planning on the parts of the oil industry, EPA, and the New York Mercantile Exchange, the introduction of reformulated gasoline was executed without problems. Ample inventories were in place for distribution in December and January. Then 28 counties in Pennsylvania, 9 in New York, and 2 in Maine made requests to opt-out of the reformulated gasoline program. EPA, 10 days later, allowed this. The paper describes what this inadequate notice of the reversal of regulations had on the futures market and the uncertainties still in the market
[en] Dominique Bussereau, Minister of Agriculture and Fishing and Francois Loos, delegate Minister of the industry, have joined in Bercy the trade of the petroleum, automobile and agricultural sectors last November (the 21.). Fifteen measures with the aim to make the development of biofuels in France advance have been taken during this round table in order to reach the aim of 5.75% of incorporation in the fuels in 2008. (O.M.)
[en] World methanol uses, production capacity for 1996 to 2000, and the overall fundamental facts about methanol consumption and supply are reviewed. Results suggest that the use of methanol as a fuel is growing rapidly and it is also tied directly with the MTBE fuel oxygenate. Methanol is competing directly with liquefied natural gas, particularly as the average cash cost of production is decreasing. Fundamentals of methanol economics are outlined, showing that with minor exceptions, methanol pricing reflects commodity products in general. There is no historical reason to expect that these fundamentals will change in the near future. In view of that, the best strategy to maintain market share is to be the lowest cost producer, keeping up efforts to enlarge markets, focusing on reliability of the product, and on economics of scale, technology and finance. Reducing capital and operating cost, and paying close attention to freight costs are equally important strategy components. Issues concerning traditional gas purchasing strategies for North American chemical companies, factors responsible for gas price volatility, and approaches to gas purchasing are also addressed. tabs., figs
[en] To explore new and multifunctional additives for methanol-gasoline, glycolic esters were synthesized and screened as phase stabilizer and saturation vapor pressure depressor. The effect of the esters structure on the efficiency was discussed. It was found that the stability of the blends depend on the length of the glycolic esters' alkoxy group, and hexyl glycolic and octyl glycolic were found to be the most effective in various gasoline-methanol blends. Additionally, the glycolic esters can depress the saturation vapor pressure of methanol-gasoline effectively as well, and decyl glycolic is the most effective one. With these data, it can be concluded that the glycolic esters have the great potential to be used as bifunctional gasoline-methanol additives. (author)
[en] CO2 is a clean carbon source for the chemical reactions, many researchers have studied the utilization of CO2. Higher alcohols are clean fuel additives. The synthesis of higher alcohols from CO hydrogenation has also been studied by many researchers, but there are few literatures about the synthesis of higher alcohols from CO2 hydrogenation, which is a complex and difficult reaction. The catalysts that used for higher alcohols synthesis need at least two active phases and good cooperation. In our study, we tested the Co. Cu. Fe spinel-based catalysts and the effect of supports (CNTs and TUD-1) and promoters (K, Na, Cs) to the HAS reaction. We found that catalyst CuFe-precursor-800 is beneficial for the synthesis of C2+ hydrocarbons and higher alcohols. In the CO2 hydrogenation, Co acts as a methanation catalyst rather than acting as a FT catalyst, because of the different reaction mechanism between CO hydrogenation and CO2 hydrogenation. In order to inhibit the formation of huge amount of hydrocarbons, it is better to choose catalysts without Co in the CO2 hydrogenation reaction. Compared the functions of CNTs and TUD-1, we found that CNTs is a perfect support for the synthesis of long-chain products (higher alcohols and C2+ hydrocarbons). The TUD-1 support are more suitable for synthesis of single-carbon products (methane and methanol).The addition of alkalis as promoters does not only lead to increase the conversion of CO2 and H2, but also sharply increased the selectivity to the desired products, higher alcohols. The catalyst 0.5K30CuFeCNTs owns the highest productivities (370.7 g.kg-1.h-1) of higher alcohols at 350 C and 50 bar. (author)
[fr]Le CO2 est une source de carbone propre pour les reactions chimiques, nombreux chercheurs ont etudie l'utilisation du CO2. Les alcools superieurs sont des additifs de carburant propres. La synthese des alcools superieurs a partir de l'hydrogenation du CO a egalement ete etudiee par de nombreux chercheurs, mais il existe peu de litteratures sur la synthese des alcools superieurs a partir de l'hydrogenation du CO2, qui est une reaction complexe et difficile. Les catalyseurs utilises pour la synthese des alcools superieurs necessitent au moins deux phases actives et une bonne synergie. Dans notre etude, nous avons etudie les catalyseurs spinelle bases sur Co. Cu. Fe et l'effet des supports (CNTs et TUD-1) et celui des promoteurs (K, Na, Cs) a la reaction de HAS. Nous avons trouve que le catalyseur CuFe-precurseur-800 est favorable pour la synthese d'hydrocarbures en C2+ et d'alcools superieurs. Dans l'hydrogenation du CO2, Co agit comme catalyseur de methanisation plutot que comme catalyseur FT, en raison du mecanisme de reaction different entre l'hydrogenation du CO et celle du CO2. Afin d'inhiber la formation d'hydrocarbures de quantites importante, il est preferable de choisir des catalyseurs sans Co dans la reaction d'hydrogenation du CO2. En comparant les fonctions des CNT et du TUD-1, nous avons constate que le CNT est un support parfait pour la synthese de produits a longue chaine (alcools superieurs et hydrocarbures C2+). Le support TUD-1 est plus adapte a la synthese de produits a un seul carbone (methane et methanol). L'addition d'alcalis en tant que promoteurs conduit non seulement a augmenter la conversion de CO2 et H2, mais augmente egalement la selectivite des produits vises fortement, des alcools superieurs. Le catalyseur 0.5K30CuFeCNTs possede une productivites les plus elevees (370.7 g . kg-1 . h-1) d'alcools superieurs a 350 deg. C et 50 bar.
[en] Lanthanide fission products can migrate to the fuel periphery and react with cladding, causing fuel-cladding chemical interaction (FCCI). Adding a fuel additive dopant, such as Sb, can bind lanthanide, such as Ce, into metallic compounds and thus prevent migration. The present study focuses on the thermodynamic stability of Ce-Sb compounds when in contact with the major cladding constituent Fe by conducting diffusion couple tests. Ce-Sb compounds have shown high thermodynamic stability as they did not react with Fe. When Fe-Sb compounds contacted with Ce, Sb was separated out of Fe-Sb compounds and formed the more stable Ce-Sb compounds.