Alternative fuel properties of tall oil fatty acid methyl ester-diesel fuel blends

In this experimental work, tall oil methyl ester-diesel fuel blends as alternative fuels for diesel engines were studied. Tall oil methyl ester was produced by reacting tall oil fatty acids with methyl alcohol under optimum conditions. The blends of tall oil methyl ester-diesel fuel were tested in a direct injection diesel engine at full load condition. The effects of the new fuel blends on the engine performance and exhaust emission were tested. It was observed that the engine torque and power output with tall oil methyl ester-diesel fuel blends increased up to 6.1% and 5.9%, respectively. It was also seen that CO emissions decreased to 38.9% and NO(x) emissions increased up to 30% with the new fuel blends. The smoke opacity did not vary significantly.     

Esters of trehalose from Corynebacterium diphtheriae: A modified purification procedure and studies on the structure of their constituent hydroxylated fatty acids

The purification procedure of 6,6′-diesters of trehalose from Corynebacterium diphtheriae was modified and the isolated substance was analysed by mass spectrometry as its permethylated derivative. The fatty acid moiety released from the glycolipid after alkaline hydrolysis was studied by mass spectral analysis of the O-methylated and O-acetylated methyl ester derivatives. By argentation thin-layer chromatography, three species of O-acetylated methyl esters were recognized, corresponding to saturated, mono-unsaturated and di-unsaturated α-branched-β-hydroxylated fatty acids. The double bond was located by ozonolysis of the O-acetylated methyl ester derivatives, by gas chromatography of the reaction product and mass spectrometry of the effluent from the gas chromatograph. The main components of each species of α-branched-β-hydroxylated fatty acids found in the gly colipid fraction of C. diphtheriae were 2-tetradecyl-3-hydroxyoctadecanoic acid (C₃₂H₆₄O₃, corynomycolic acid), 2-tetradecyl-3-hydroxy-11-octadecenoic acid (C₃₂H₆₂O₃, corynomycolenic acid), 2-tetradec-7′-enyl-3-hydroxy octadecanoic acid (C₃₂H₆₂O₃) and 2-tetradec-7′-enyl-3-hydroxy-11-octadecenoic acid (C₃₂H₆₀O₃, corynomycoldienic acid). The glycolipid fraction from C. diphtheriae is obviously a complex mixture of 6,6′-diesters of trehalose.     

Combustion characteristics of a turbocharged DI compression ignition engine fueled with petroleum diesel fuels and biodiesel

In this study, the combustion characteristics and emissions of two different petroleum diesel fuels (No. 1 and No. 2) and biodiesel from soybean oil were compared. The tests were performed at steady state conditions in a four-cylinder turbocharged DI diesel engine at full load at 1400-rpm engine speed. The experimental results compared with No. 2 diesel fuel showed that biodiesel provided significant reductions in PM, CO, and unburned HC, the NO(x) increased by 11.2%. Biodiesel had a 13.8% increase in brake-specific fuel consumption due to its lower heating value. However, using No. 1 diesel fuel gave better emission results, NO(x) and brake-specific fuel consumption reduced by 16.1% and 1.2%, respectively. The values of the principal combustion characteristics of the biodiesel were obtained between two petroleum diesel fuels. The results indicated that biodiesel may be blended with No. 1 diesel fuel to be used without any modification on the engine.     

Effects of mixing system and pilot fuel quality on diesel–biogas dual fuel engine performance

This paper describes results obtained from CI engine performance running on dual fuel mode at fixed engine speed and four loads, varying the mixing system and pilot fuel quality, associated with fuel composition and cetane number. The experiments were carried out on a power generation diesel engine at 1500 m above sea level, with simulated biogas (60% CH₄–40% CO₂) as primary fuel, and diesel and palm oil biodiesel as pilot fuels. Dual fuel engine performance using a naturally aspirated mixing system and diesel as pilot fuel was compared with engine performance attained with a supercharged mixing system and biodiesel as pilot fuel. For all loads evaluated, was possible to achieve full diesel substitution using biogas and biodiesel as power sources. Using the supercharged mixing system combined with biodiesel as pilot fuel, thermal efficiency and substitution of pilot fuel were increased, whereas methane and carbon monoxide emissions were reduced.     

Catalytic conversion of Botryococcus braunii oil to diesel fuel under mild reaction conditions

Although the non-oxygenated triterpenic hydrocarbons (primarily C₃₄H₅₈) produced by the Bot-22 strain of Botryococcus braunii are exceptionally promising candidates for automobile fuel applications, it remains necessary to develop appropriate cracking technologies to convert these oils into a fuel with the required properties. The aim of this research was to develop an on-site process capable of converting the oil extracted from Bot-22 (Bot-oil) to a fuel that satisfies the specifications for diesel fuels, a so-called “drop-in” fuel. One of our primary goals for this on-site conversion was to have it operate as a low-temperature process. In this study, an experimental analysis of Bot-oil catalytic conversion under mild conditions was performed. The results demonstrated that the Bot-oil conversion reaction will proceed at temperatures as low as approximately 200 °C, and that the lowest temperature which resulted in a suitably efficient reaction was found to be 260 °C, generating a yield of 85 %. The physical properties of the converted oil were found to come close to satisfying Japan’s JIS #2 diesel fuel specification. The converted oil’s cetane number (CN), one of the most important quality indexes of diesel fuels, was estimated by measuring its ignition delay in a constant-volume combustion chamber. The estimated CN of the converted oil had a value of 40, which is 5 points below the JIS #2 requirement. It is thought that the Bot-oil can be used to produce a drop-in fuel using a simple on-site conversion process, although further development is required to achieve this aim.     

Tuber-forming Substances in Jerusalem Artichoke (Helianthus tuberosus L.)

Four tuber-forming substances in Jerusalem artichoke were isolated from the leaves. The structures were established by spectroscopic methods as jasmonic acid (2), methyl β-D-glucopyranosyl tuberonate (3), and two new polyacetylene compounds, methyl β-D-glucopyranosyl helianthenate A (4, C₁₉H₂₄O₈) and B (5, C₁₇H₂₂O₈).     

Antifungal Constituent of Sapium japonicum

An antifungal constituent, C₉H₁₄O₃, containing allenic double bond, was isolated from the leaves of Sapium japonicum (Euphorbiaceae). The structure of this antifungal constituent was shown to be methyl 8-hydroxy-5, 6-octadienoate.     

Studies on Mitomycins,Carcinostatic Antibiotics

Mitomycin A (C₁₆H₁₉O₆N₃) and mitomycin C (C₁₅H₁₈O₅N₄) are pigments which have the quinoid structure. When treated with aqueous ammonia, mitomycin A is converted to mitomycin C. Acid hydrolysis of mitomycin C gave three degradation products, namely, C₁₄H₁₅O₅N₄, C₁₄H₁₅O₆N₃ and C₁₃H₁₄O₅N₂. Acetylation with acetic anhydride and pyridine and methylation with methyl iodide gave monoacetyl and monomethyl derivatives of mitomycin C respectively, though diacetate of demethyl derivatives were obtained when boiled with acetic anhydride.     

Sedimentary records of carbonaceous particles from fossil fuel combustion

Carbonaceous particles produced by fossil fuel combustion can be found in considerable amounts in recent lake sediments. As these particles contain elemental carbon they are resistant to chemical decomposition and therefore both well preserved in sediments and possible to quantify. Sediment samples can be oxidized with H₂O₂ and digested with HF without the particles being destroyed. The pioneers in studying carbonaceous particles in lake sediments in relation to fossil fuel combustion were J. J. Griffin and E. D. Goldberg. They measured elemental carbon concentrations in Lake Michigan sediments, mainly by infrared assay. On the basis of these analyses, size distribution measurements and also morphological studies of single particles they concluded that the carbonaceous particle record reflected the onset of industrial activity and the increased intensities of fossil fuel combustion during the twentieth century. Similar results have been obtained from another lake in the USA by B. K. Kothari and M. Wahlen. We have counted spherical carbonaceous particles (larger than 5–10 µm), which are characteristic for oil and coal burning, in several lake sediments. In Swedish lakes, the annual accumulation of coarse carbonaceous spheres in varved sediments and the concentration stratigraphy in non-varved sediments, follow the same main pattern as statistical data for the Swedish coal and oil combustion over the last two centuries. Coarse carbonaceous spheres in two sediment profiles from Scottish lakes have also been counted. As for the USA and Sweden the sedimentary record was found to reflect the history of fossil fuel combustion.     

Influence of tall oil biodiesel with Mg and Mo based fuel additives on diesel engine performance and emission

The purpose of this study is to investigate influences of tall oil biodiesel with Mg and Mo based fuel additives on diesel engine performance and emission. Tall oil resinic acids were reacted with MgO and MoO(2) stoichiometrically for the production of metal-based fuel additives (combustion catalysts). The metal-based additives were added into tall oil biodiesel (B60) at the rate of 4 micromol/l, 8 micromol/l and 12 micromol/l for preparing test fuels. In general, both of the metal-based additives improved flash point, pour point and viscosity of the biodiesel fuel, depending on the rate of additives. A single cylinder DI diesel engine was used in the tests. Engine performance values did not change significantly with biodiesel fuels, but exhaust emission profile was improved. CO emissions and smoke opacity decreased by 56.42% and by 30.43%, respectively. In general, low NO(x) and CO(2) emissions were measured with the biodiesel fuels.     

Reaction of Phosphinyl and Phosphinothioyl Disulfides with Diazomethane

Four kinds of 4-substituted phenyl diethoxyphosphinyl disulfide (substitueras: H, CH₃, C₂H₅, Cl) and phenyl diethoxyphosphinothioyl disulfide reacted readily with diazomethane. The phosphinyl disulfides produced diethyl (4-substituted phenylthio)methyl phosphorothionate and the isomer, diethyl S-(4-substituted phenylthio)methyl phosphorothiolate, as the main products, whereas the phosphinothioyl disulfide produced only diethyl S-(phenylthio)methyl phosphorodithioate.

The possible mechanism involved is as follows: the S-S bond in (EtO)₂P(X)-S-S-C₆H₄R (X = O or S) is cleaved by nucleophilic attack of diazomethane at the sulfur atom bonded to the phenyl group to produce and ^⊕ N₂CH₂–S–C₆H₄R; the latter reacts with the former with loss of nitrogen; therefore, when X is O, two compounds, (EtO)₂P(S)–O–CH₂–S–C₆H₄R and (EtO)₂P(O)–S–CH₂–S–C₆H₄R, are produced, when X is S, only (EtO)₂P(S)–S–CH₂ –S–C₆H₄R is obtained.     

Crude oil production and classification of organic compounds on super-critical liquefaction with rice hull

The liquefaction of rice hull (a typical agricultural waste) has been conducted with n-butanol solvent at various reaction temperatures ranging from 260 to 320°C. As a result, it was found that biomass conversion rates were increased with increasing temperature up to 320dgC. However, it was observed that its rate of conversion to liquid was about 83% at 320°C for 30 min. The crude oil yield with rice hull increased up to 1,273 mg/g/L at 300°C, but the yield of Fraction 1 at 280°C was raised suddenly, and peaked at 2 times that of the initial input amount of feedstock. Furthermore, the calorific values of crude oil and Fraction 1 from rice hull were about 5,843 and 8,061 kcal/kg and were enhanced 163 and 225%, respectively, relative to its feedstock as rice hull, respectively. Fraction 1 may be suitable as an alternative liquid fuel of gasoline, based on an engine performance test. Sixty species of organic compounds in crude oil were categorized into 8 classes of compounds, including acids, alcohols, aliphatic hydrocarbons, ethers, esters, ketones, phenol, and aromatics, and others. In the crude oil from rice hull, the most common chemical types were esters and ethers accounting for 32.0 and 19.2% of the total extract, respectively. Analysis of Fraction 1 revealed that the main chemical components were C₅H₁₂O, C₇H₁₄O₂, C₈H₁₆O₂, and C₁₂H₂₆O₂. Therefore, for producing clean and green fuel energy with plant biomass liquefaction it is necessary to further investigate crude oil and to further refine Fraction 1 through catalytic cracking or hydro-de-oxygenation (HDO).     

The pyruvate: Ferredoxin oxidoreductase in heterocysts of the cyanobacteriuim Anabaena cylindrica

Heterocyst preparations have been obtained which actively perform nitrogen fixation (C₂H₂ reduction) and contain the enzymes of glycolysis and some of the tricarboxylic acid cycle. Pyruvate: ferredoxin oxidereductase has been unambiguously demonstrated in extracts from heterocysts by the formation of acetylcoenzyme A, CO₂ and reduced methyl viologen (ferredoxi) from pyruvate, coenzyme A and oxidized methyl viologen (ferredoxin) as well as by the synthesis of pyruvate from CO₂, acetylcoenzyme A and reduced methyl viologen. Pyruvate supports C₂H₂ reduction by isolated heterocysts, however, with lower activity than Na₂S₂O₄ and H₂. α-Ketoglutarate: ferredoxin oxidoreductase is absent in Anabaena cylindrica, confirming that the organism has an incomplete tricarboxylic acid cycle.     

Respiration in Adipocytes is Inhibited by Reactive Oxygen Species

It is a desirable goal to stimulate fuel oxidation in adipocytes and shift the balance toward less fuel storage and more burning. To understand this regulatory process, respiration was measured in primary rat adipocytes, mitochondria, and fat‐fed mice. Maximum O₂ consumption, in vitro, was determined with a chemical uncoupler of oxidative phosphorylation (carbonylcyanide p‐trifluoromethoxyphenylhydrazone (FCCP)). The adenosine triphosphate/adenosine diphosphate (ATP/ADP) ratio was measured by luminescence. Mitochondria were localized by confocal microscopy with MitoTracker Green and their membrane potential (Δψ_M) measured using tetramethylrhodamine ethyl ester perchlorate (TMRE). The effect of N‐acetylcysteine (NAC) on respiration and body composition in vivo was assessed in mice. Addition of FCCP collapsed Δψ_M and decreased the ATP/ADP ratio. However, we demonstrated the same rate of adipocyte O₂ consumption in the absence or presence of fuels and FCCP. Respiration was only stimulated when reactive oxygen species (ROS) were scavenged by pyruvate or NAC: other fuels or fuel combinations had little effect. Importantly, the ROS scavenging role of pyruvate was not affected by rotenone, an inhibitor of mitochondrial complex I. In addition, mice that consumed NAC exhibited increased O₂ consumption and decreased body fat in vivo. These studies suggest for the first time that adipocyte O₂ consumption may be inhibited by ROS, because pyruvate and NAC stimulated respiration. ROS inhibition of O₂ consumption may explain the difficulty to identify effective strategies to increase fat burning in adipocytes. Stimulating fuel oxidation in adipocytes by decreasing ROS may provide a novel means to shift the balance from fuel storage to fuel burning.     

A Piscicidal Constituent of Sapium japonicum

A piscicidal constituent, C₃₂H₄₂O₈, was isolated from Sapium japonicum. On the basis of the chemical and spectral studies, the structure of the piscicidal constituent was shown to be 1a, 12-O-n-deca-2,4,6-trienoyl-phorbol-(13)-acetate.     

Biodegradation of diesel fuel by a microbial consortium in the presence of 1-alkoxymethyl-2-methyl-5-hydroxypyridinium chloride homologues

Fast development of ionic liquids as gaining more and more attention valuable chemicals will undoubtedly lead to environmental pollution. New formulations and application of ionic liquids may result in contamination in the presence of hydrophobic compounds, such as petroleum mixtures. We hypothesize that in the presence of diesel fuel low-water-soluble ionic liquids may become more toxic to hydrocarbon-degrading microorganisms. In this study the influence of 1-alkoxymethyl-2-methyl-5-hydroxypyridinium chloride homologues (side-chain length from C₃ to C₁₈) on biodegradation of diesel fuel by a bacterial consortium was investigated. Whereas test performed for the consortium cultivated on disodium succinate showed that toxicity of the investigated ionic liquids decreased with increase in side-chain length, only higher homologues (C₈–C₁₈) caused a decrease in diesel fuel biodegradation. As a result of exposure to toxic compounds also modification in cell surface hydrophobicity was observed (MATH). Disulphine blue active substances method was employed to determine partitioning index of ionic liquids between water and diesel fuel phase, which varied from 1.1 to 51% for C₃ and C₁₈ homologues, respectively. We conclude that in the presence of hydrocarbons acting as a solvent, the increased bioavailability of hydrophobic homologues is responsible for the decrease in biodegradation efficiency of diesel fuel.     

Isolation of Novel Antifungal Antibiotics,Ezomycins A1, A2, B1 and B2

From ezomycin complex produced by a strain of Streptomyces were isolated four components named ezomycins A₁ (C₂₆H₄₀N₈O₁₆S), A₂ (C₁₉H₂₈N₆O₁₃), B₁ (C₂₆H₃₉N₇O₁₇S) and B₂ (C₁₉H₂₇N₅O₁₄) which are new pyrimidine nucleosides. Ezomycins A₁ and B₁ containing l-cystathionine were found to be responsible for specific antimicrobial activity of the complex against Sclerotinia and Botrytis species.     

Potent methyl oxidation of 5-methyl-2′-deoxycytidine by halogenated quinoid carcinogens and hydrogen peroxide via a metal-independent mechanism

Halogenated quinones are a class of carcinogenic intermediates and are newly identified chlorination disinfection by-products in drinking water. We found recently that the highly reactive and biologically important hydroxyl radical (^•OH) can be produced by halogenated quinones and H₂O₂ independent of transition metal ions. However, it is not clear whether these quinoid carcinogens and H₂O₂ can oxidize the nucleoside 5-methyl-2′-deoxycytidine (5mdC) to its methyl oxidation products and, if so, what the underlying molecular mechanism is. Here we show that three methyl oxidation products, 5-(hydroperoxymethyl)-, 5-(hydroxymethyl)-, and 5-formyl-2′-deoxycytidine, could be produced when 5mdC was treated with tetrachloro-1,4-benzoquinone (TCBQ) and H₂O₂. The formation of the oxidation products was markedly inhibited by typical ^•OH scavengers and under anaerobic conditions. Analogous effects were observed with other halogenated quinones and the classic Fenton system. Based on these data, we propose that the oxidation of 5mdC by TCBQ/H₂O₂ might be through the following mechanism: ^•OH produced by TCBQ/H₂O₂ may first abstract hydrogen from the methyl group of 5mdC, leading to the formation of 5-(2′-deoxycytidylyl)methyl radical, which may combine with O₂ to form the peroxyl radical. The unstable peroxyl radical transforms into the corresponding hydroperoxide 5-(hydroperoxymethyl)-2′-deoxycytidine, which reacts with TCBQ and results in the formation of 5-(hydroxymethyl)-2′-deoxycytidine and 5-formyl-2′-deoxycytidine. This is the first report that halogenated quinoid carcinogens and H₂O₂ can induce potent methyl oxidation of 5mdC via a metal-independent mechanism, which may partly explain their potential carcinogenicity.     

Synthesis and characterization of vegetable oil derived esters: evaluation for their diesel additive properties

Trans-esterification of four vegetable oils; canola oil, greenseed canola oil from heat-damaged seeds, processed waste fryer grease and unprocessed waste fryer grease, was carried out using methanol, and KOH as catalyst. The methyl esters of the corresponding oils were separated from the crude glycerol, purified, and characterized by various methods to evaluate their densities, viscosities, iodine values, acid numbers, cloud points, pour points and gross heat of combustion, fatty acid and lipid compositions, lubricity properties, and thermal properties. The fatty acid composition suggests that 80-85% of the ester was from unsaturated acids. Substantial decrease in density and viscosity of the methyl esters compared to their corresponding oils suggested that the oils were in their mono or di glyceride form. The lubricity of the methyl esters, when blended at 1 vol% treat rate with ISOPAR M reference fuel, showed that the canola methyl ester enhanced the fuel's lubricity number. From the analyses performed, it was determined that the ester with the most potential for being an additive or a substitute for diesel fuel is the canola methyl ester, whose physical and chemical characteristics are similar to diesel fuel.