Lipase-catalysed production of biodiesel fuel from some Nigerian lauric oils

Fatty acids esters were produced from two Nigerian lauric oils, palm kernel oil and coconut oil, by transesterification of the oils with different alcohols using PS30 lipase as a catalyst. In the conversion of palm kernel oil to alkyl esters (biodiesel), ethanol gave the highest conversion of 72%, t-butanol 62%, 1-butanol 42%, n-propanol 42% and iso-propanol 24%, while only 15% methyl ester was observed with methanol. With coconut oil, 1-butanol and iso-butanol achieved 40% conversion, 1-propanol 16% and ethanol 35%, while only traces of methyl esters were observed using methanol. Studies on some fuel properties of palm kernel oil and its biodiesel showed that palm kernel oil had a viscosity of 32.40 mm2/s, a cloud point of 28 degrees C and a pour point of 22 degrees C, while its biodiesel fuel had a viscosity of 9.33 mm2/s, a cloud point of 12 degrees C and a pour point of 8 degrees C. Coconut oil had a viscosity of 28.58 mm(2)/s, a cloud point of 27 degrees C and a pour point of 20 degrees C, while its biodiesel fuel had a viscosity of 7.34 mm2/s, a cloud point of 5 degrees C and a pour point of -8 degrees C. Some of the fuel properties compared favourably with international biodiesel specifications.     

Direct preparation of biodiesel from rapeseed oil leached by two-phase solvent extraction

A new method which coupled the two-phase solvent extraction (TSE) with the synthesis of biodiesel was studied. Investigations were carried out on transesterification of methanol with oil-hexane solution coming from TSE process in the presence of sodium hydroxide as the catalyst. Biodiesel (fatty acid methyl esters) were the products of transesterification. The influential factors of transesterification, such as reaction time, catalyst concentration, mole ratio of methanol to oil and reaction temperature were optimized. The results showed that the optimal reaction parameters were sodium hydroxide concentration 1.1% by weight of rapeseed oil, mole ratio of methanol to oil 9:1, reaction time 120 min, and reaction temperature 55-60 degrees C. Under these conditions, the TG conversion would rise up to 98.2%. Based on the new method, biodiesel production process could be simplified and the biodiesel cost could be reduced.     

Solubility of multi-component biodiesel fuel systems

Solubility of biodiesel fuel components in fossil diesel fuel-methanol-rapeseed oil methyl ester, fossil diesel fuel-ethanol-rapeseed oil methyl ester and fossil diesel fuel-ethanol-rapeseed oil ethyl ester systems was investigated. The solubility of components in the fossil diesel fuel-ethanol-rapeseed oil methyl ester system at 20 degrees C was substantially higher than in the fossil diesel fuel-methanol-rapeseed oil methyl ester system. The solubility of components in the fossil diesel fuel-ethanol-rapeseed oil ethyl ester system was slightly lower than in the fossil diesel fuel-ethanol-rapeseed oil methyl ester mixture. The moisture content of ethanol had a great influence on mixture solubility. With decrease of temperature, the solubility of components in the fossil diesel fuel-ethanol-rapeseed oil methyl ester system decreased.     

Microbial degradation of palm (Elaeis guineensis) biodiesel

The kinetics of biodegradation of palm-derived fatty methyl and ethyl esters (Elaeis guineensis biodiesel) by a wild-type aerobic bacterial population was measured at 20 degrees C, as the rate of oxygen uptake by a manometric technique. The methyl and ethyl biodiesels were obtained by potassium-hydroxide catalysed trans-esterification of palm oil, respectively. The bacterial flora included the genera Bacillus, Proteus, Pseudomonas, Citrobacter and Enterobacter. The rate of oxygen uptake for palm biodiesel is similar to the quantity observed in the biodegradation of 1.0 mM solutions of simple substrates such as carbohydrates or amino acids. Palm methyl or ethyl biodiesel is subjected to facile aerobic biodegradation by wild-type bacteria commonly present in natural open environments. This result should lessen any environmental concern for its use as alternative fuel, solvent or lubricant.     

Production of Cold-Flow Quality Biodiesel from High-Acidity On-Edible Oils—Esterification and Transesterification of Macauba (<Emphasis Type="Italic">Acrocomia aculeata</Emphasis>) Oil Using Various Alcohols

Biodiesel is an alternative fuel that has been used for partial or total substitution of diesel to reduce its environmental impacts. Prior studies on this topic have focused on the quest for better synthesis process, new catalysts and low-cost non-food and raw materials to improve the economic and sustainable production as well as product quality. In this study, acidic oil from macauba, a palm tree native to South America that has no food uses, was converted into biodiesel. The esterification and transesterification reactions were performed with methanol, ethanol and isobutanol with the goal of improving the cold properties of the biodiesel. The isobutyl ester exhibited the lowest freezing point temperature but underperformed outside of international specifications for kinematic viscosity; it also exhibited a low ester content. The methyl and ethyl esters were within the specifications of the international standards for ester content, density, kinematic viscosity and sulphur content. The ethyl ester produced from macauba oil displayed better properties in cold conditions than methyl and isobutyl esters studied here, with a cold filter plugging point of 0 °C. Its onset crystallisation temperature was reduced from ?5.96 to ?13.41 °C when subjected to fractional crystallisation. The ethyl ester exhibited the best lubricity value among the other esters studied.     

Moringa oleifera oil: a possible source of biodiesel

Biodiesel is an alternative to petroleum-based conventional diesel fuel and is defined as the mono-alkyl esters of vegetable oils and animal fats. Biodiesel has been prepared from numerous vegetable oils, such as canola (rapeseed), cottonseed, palm, peanut, soybean and sunflower oils as well as a variety of less common oils. In this work, Moringa oleifera oil is evaluated for the first time as potential feedstock for biodiesel. After acid pre-treatment to reduce the acid value of the M. oleifera oil, biodiesel was obtained by a standard transesterification procedure with methanol and an alkali catalyst at 60 degrees C and alcohol/oil ratio of 6:1. M. oleifera oil has a high content of oleic acid (>70%) with saturated fatty acids comprising most of the remaining fatty acid profile. As a result, the methyl esters (biodiesel) obtained from this oil exhibit a high cetane number of approximately 67, one of the highest found for a biodiesel fuel. Other fuel properties of biodiesel derived from M. oleifera such as cloud point, kinematic viscosity and oxidative stability were also determined and are discussed in light of biodiesel standards such as ASTM D6751 and EN 14214. The (1)H NMR spectrum of M. oleifera methyl esters is reported. Overall, M. oleifera oil appears to be an acceptable feedstock for biodiesel.     

Acid-catalyzed esterification of Zanthoxylum bungeanum seed oil with high free fatty acids for biodiesel production

A technique to produce biodiesel from crude Zanthoxylum bungeanum seed oil (ZSO) with high free fatty acids (FFA) was developed. The acid value of ZSO was reduced to 1.16mg KOH/g from 45.51mg KOH/g by only one-step acid-catalyzed esterification with methanol-to-oil molar ratio 24:1, H(2)SO(4) 2%, temperature 60 degrees C and reaction time 80min, which was selected as optimum for the acid-catalyzed esterification. During the acid-catalyzed esterification, FFA was converted into fatty acid methyl esters, which was confirmed by (1)H NMR spectrum. Compared with the other two-step pretreatment procedure, this one-step pretreatment can reduce the production cost of ZSO biodiesel. Alkaline-catalyzed transesterification converted the pretreated ZSO into ZSO biodiesel. The yield of ZSO biodiesel was above 98% determined by (1)H NMR spectrum. This study supports the use of crude ZSO as a viable and valuable raw feedstock for biodiesel production.     

Lipase-catalyzed biodiesel production from waste activated bleaching earth as raw material in a pilot plant

The production of fatty acid methyl esters (FAMEs) from waste activated bleaching earth (ABE) discarded by the crude oil refining industry using lipase from Candida cylindracea was investigated in a 50-L pilot plant. Diesel oil or kerosene was used as an organic solvent for the transesterification of triglycerides embedded in the waste ABE. When 1% (w/w) lipase was added to waste ABE, the FAME content reached 97% (w/w) after reaction for 12 h at 25 degrees C with an agitation rate of 30 rpm. The FAME production rate was strongly dependent upon the amount of enzyme added. Mixtures of FAME and diesel oil at ratios of 45:55 (BDF-45) and 35:65 (BDF-35) were assessed and compared with the European specifications for biodiesel as automotive diesel fuel, as defined by pr EN 14214. The biodiesel quality of BDF-45 met the EN 14214 standard. BDF-45 was used as generator fuel, and the exhaust emissions were compared with those of diesel oil. The CO and SO2 contents were reduced, but nitrogen oxide emission increased by 10%. This is the first report of a pilot plant study of lipase-catalyzed FAME production using waste ABE as a raw material. This result demonstrates a promising reutilization method for the production of FAME from industrial waste resources containing vegetable oils for use as a biodiesel fuel.     

Preparation of biodiesel from crude oil of Pongamia pinnata

Biodiesel was prepared from the non-edible oil of Pongamia pinnata by transesterification of the crude oil with methanol in the presence of KOH as catalyst. A maximum conversion of 92% (oil to ester) was achieved using a 1:10 molar ratio of oil to methanol at 60 degrees C. Tetrahydrofuran (THF), when used as a co-solvent increased the conversion to 95%. Solid acid catalysts viz. Hbeta-Zeolite, Montmorillonite K-10 and ZnO were also used for this transesterification. Important fuel properties of methyl esters of Pongamia oil (Biodiesel) compare well (Viscosity = 4.8 Cst @ 40 degrees C and Flash point = 150 degrees C) with ASTM and German biodiesel standards.     

Pyrolysis of glycerol for the production of hydrogen or syn gas

Biodiesel has high potential as alternative liquid transportation fuel because it is renewable and CO(2) neutral, and has similar properties as diesel fuel. Glycerol is a by-product obtained during the production of biodiesel. Canadian government has planned to produce 500 million litres of biodiesel by 2010. An increase in biodiesel production would decrease the market price of glycerol. The objective of this study is to pyrolyse glycerol for the production of clean fuels such as H(2) or a feedstock such as syn gas for additional transportation fuel via Fisher-Tropsch synthesis. The pyrolysis of glycerol was carried out at various flow rates of N(2) (30-70 mL/min), temperatures (650-800 degrees C) and types and sizes of packing material in a tubular reactor at atmospheric pressure. The products were mostly gas, essentially consisting of CO, H(2), CO(2), CH(4) and C(2)H(4). It was observed that temperature, carrier flow rates and particle diameter of packing material had profound effects on the conversion of glycerol as well as product distribution. Composition of product gas ranged between syn gas 70-93 mol%, CH(4) 3-15 mol% and C(2)H(4) 2-12 mol% and heating value ranged from 13 to 22 MJ/m(3). This study indicates that the bio-glycerol has potential in making syn gas and medium heating value gases.     

High quality biodiesel production from a microalga Chlorella protothecoides by heterotrophic growth in fermenters

The aim of the study was to obtain high quality biodiesel production from a microalga Chlorella protothecoids through the technology of transesterification. The technique of metabolic controlling through heterotrophic growth of C. protothecoides was applied, and the heterotrophic C. protothecoides contained the crude lipid content of 55.2%. To increase the biomass and reduce the cost of alga, corn powder hydrolysate instead of glucose was used as organic carbon source in heterotrophic culture medium in fermenters. The result showed that cell density significantly increased under the heterotrophic condition, and the highest cell concentration reached 15.5 g L(-1). Large amount of microalgal oil was efficiently extracted from the heterotrophic cells by using n-hexane, and then transmuted into biodiesel by acidic transesterification. The biodiesel was characterized by a high heating value of 41 MJ kg(-1), a density of 0.864 kg L(-1), and a viscosity of 5.2 x 10(-4) Pa s (at 40 degrees C). The method has great potential in the industrial production of liquid fuel from microalga.     

Preparation and characterization of bio-diesels from various bio-oils

Methyl, ethyl, 2-propyl and butyl esters were prepared from canola and linseed oils through transesterification using KOH and/ or sodium alkoxides as catalysts. In addition, methyl and ethyl esters were prepared from rapeseed and sunflower oils using the same catalysts. Chemical composition of the esters was determined by HPLC for the class of lipids and by GC for fatty acid compositions. The bio-diesel esters were characterized for their physical and fuel properties including density, viscosity, iodine value, acid value, cloud point, pure point, gross heat of combustion and volatility. Methyl and ethyl esters prepared from a particular vegetable oil had similar viscosities, cloud points and pour points, whereas methyl, ethyl, 2-propyl and butyl esters derived from a particular vegetable oil had similar gross heating values. However, their densities, which were 2 7% higher than those of diesel fuels, statistically decreased in the order of methyl approximately 2-propyl > ethyl > butyl esters. Butyl esters showed reduced cloud points (-6 degrees C to -10 degrees C) and pour points (-13 degrees C to -16 degrees C) similar to those of summer diesel fuel having cloud and pour points of -8 degrees C and -15 degrees C, respectively. The viscosities of bio-diesels (3.3-7.6 x 10(-4) Pa s at 40 degrees C) were much less than those of pure oils (22.4-45.1 x 10(-4) Pa s at 40 degrees C) and were twice those of summer and winter diesel fuels (3.50 and 1.72 x 10(-4) Pa s at 40 degrees C), and their gross heat contents of approximately 40 MJ/kg were 11% less than those of diesel fuels (approximately 45 MJ/kg). For different esters from the same vegetable oil, methyl esters were the most volatile, and the volatility decreased as the alkyl group grew bulkier. However, the bio-diesels were considerably less volatile than the conventional diesel fuels.     

<Emphasis Type="Italic">Fremyella diplosiphon</Emphasis> as a Biodiesel Agent: Identification of Fatty Acid Methyl Esters via Microwave-Assisted Direct In Situ Transesterification

Increasing concerns on environmental and economic issues linked to fossil fuel use has driven great interest in cyanobacteria as third-generation biofuel agents. In this study, the biodiesel potential of a model photosynthetic cyanobacterium, Fremyella diplosiphon, was identified by fatty acid methyl esters (FAME) via direct transesterification. Total lipids in wild type (Fd33) and halotolerant (HSF33-1 and HSF33-2) strains determined by gravimetric analysis yielded 19% cellular dry weight (CDW) for HSF33-1 and 20% CDW for HSF33-2, which were comparable to Fd33 (18% CDW). Gas chromatography-mass spectrometry detected a high ratio of saturated to unsaturated FAMEs (2.48–2.61) in transesterified lipids, with methyl palmitate being the most abundant (C16:0). While theoretical biodiesel properties revealed high cetane number and oxidative stability, high cloud and pour point values indicated that fuel blending could be a viable approach. Significantly high FAME abundance in total transesterified lipids of HSF33-1 (40.2%) and HSF33-2 (69.9%) relative to Fd33 (25.4%) was identified using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry, indicating that robust salt stress response corresponds to higher levels of extractable FAME. Alkanes, a key component in conventional fuels, were present in F. diplosiphon transesterified lipids across all strains confirming that natural synthesis of these hydrocarbons is not inhibited during biodiesel production. While analysis of photosynthetic pigments and phycobiliproteins did not reveal significant differences, FAME abundance varied significantly in wild type and halotolerant strains indicating that photosynthetic pathways are not the sole factors that determine fatty acid production. We characterize the potential of F. diplosiphon for biofuel production with FAME yields in halotolerant strains higher than the wild type with no loss in photosynthetic pigmentation.     

A novel enzymatic route for biodiesel production from renewable oils in a solvent-free medium

A new enzymatic route for biodiesel production from soybean oil was developed using methyl acetate as a novel acyl acceptor. Novozym 435 (immobilized Candida antarctica lipase) gave the highest methyl ester (ME) yield of 92%. The optimum conditions of the transesterification were 30% enzyme based on oil weight; a molar ratio of methyl acetate/oil of 12:1; temperature 40 °C and reaction time 10 h. Since no glycerol was produced in the process, this method is very convenient for recycling the catalyst and by-product triacetylglycerol showed no negative effect on the fuel property.     

Synthesis,spectroscopic and chromatographic studies of sunflower oil biodiesel using optimized base catalyzed methanolysis

Methyl esters from vegetable oils have attracted a great deal of interest as substitute for petrodiesel to reduce dependence on imported petroleum and provide an alternate and sustainable source for fuel with more benign environmental properties. In the present study biodiesel was prepared from sunflower seed oil by transesterification by alkali-catalyzed methanolysis. The fuel properties of sunflower oil biodiesel were determined and discussed in the light of ASTM D6751 standards for biodiesel. The sunflower oil biodiesel was chemically characterized with analytical techniques like FT-IR, and NMR (¹H and ¹³C). The chemical composition of sunflower oil biodiesel was determined by GC–MS. Various fatty acid methyl esters (FAMEs) were identified by retention time data and verified by mass fragmentation patterns. The percentage conversion of triglycerides to the corresponding methyl esters determined by ¹H NMR was 87.33% which was quite in good agreement with the practically observed yield of 85.1%.     

Biodegradation of diesel/biodiesel blends by a consortium of hydrocarbon degraders: effect of the type of blend and the addition of biosurfactants

Biodegradation experiments for diesel/biodiesel blends in liquid cultures by-petroleum degrading microbial consortium showed that for low amendments of biodiesel (10%) the overall biodegradation efficiency of the mixture after seven days was lower than for petroleum diesel fuel. Preferential usage of methyl esters in the broad biodiesel concentration range and diminished biodegradation of petroleum hydrocarbons for 10% biodiesel blend was confirmed. Rhamnolipids improved biodegradation efficiency only for blends with low content of biodiesel. Emulsion formation experiments showed that biodiesel amendments significantly affected dispersion of fuel mixtures in water. The presence of rhamnolipids biosurfactant affected stability of such emulsions and altered cell surface properties of tested consortium.     

Biodiesel production from crude Jatropha curcas L. seed oil with a high content of free fatty acids

A technique to produce biodiesel from crude Jatropha curcas seed oil (CJCO) having high free fatty acids (15%FFA) has been developed. The high FFA level of JCJO was reduced to less than 1% by a two-step pretreatment process. The first step was carried out with 0.60 w/w methanol-to-oil ratio in the presence of 1% w/w H(2)SO(4) as an acid catalyst in 1-h reaction at 50 degrees C. After the reaction, the mixture was allowed to settle for 2h and the methanol-water mixture separated at the top layer was removed. The second step was transesterified using 0.24 w/w methanol to oil and 1.4% w/w NaOH to oil as alkaline catalyst to produce biodiesel at 65 degrees C. The final yield for methyl esters of fatty acids was achieved ca. 90% in 2 h.     

Optimization of direct conversion of wet algae to biodiesel under supercritical methanol conditions

This study demonstrated a one-step process for direct liquefaction and conversion of wet algal biomass containing about 90% of water to biodiesel under supercritical methanol conditions. This one-step process enables simultaneous extraction and transesterification of wet algal biomass. The process conditions are milder than those required for pyrolysis and prevent the formation of by-products. In the proposed process, fatty acid methyl esters (FAMEs) can be produced from polar phospholipids, free fatty acids, and triglycerides. A response surface methodology (RSM) was used to analyze the influence of the three process variables, namely, the wet algae to methanol (wt./vol.) ratio, the reaction temperature, and the reaction time, on the FAMEs conversion. Algal biodiesel samples were analyzed by ATR-FTIR and GC-MS. Based on the experimental analysis and RSM study, optimal conditions for this process are reported as: wet algae to methanol (wt./vol.) ratio of around 1:9, reaction temperature and time of about 255 °C, and 25 min respectively. This single-step process can potentially be an energy efficient and economical route for algal biodiesel production.     

Aerobic Biodegradation of Liquid Motor Fuels under Extreme Acidic Conditions

Microbiology - Biodegradation of liquid petroleum motor fuels and fuel mixtures containing biodiesel fuel (methyl ethers of rapeseed fatty acids) by aerobic acidophilic actinobacteria Mycobacterium...     

Transesterification of soybean oil using combusted oyster shell waste as a catalyst

Transesterification of soybean oil catalyzed by combusted oyster shell, which is waste material from shellfish farms, was examined. Powdered oyster shell combusted at a temperature above 700 degrees C, at which point the calcium carbonate of oyster shell transformed to calcium oxide, acted as a catalyst in the transesterification of soybean oil. On the basis of factorial design, the reaction conditions of catalyst concentration and reaction time were optimized in terms of the fatty acid methyl ester concentration expressed as biodiesel purity. Under the optimized reaction conditions of a catalyst concentration and reaction time of 25wt.%. and 5h, respectively, the biodiesel yield, expressed relative to the amount of soybean oil poured into the reaction vial, was more than 70% with high biodiesel purity. These results indicate oyster shell waste combusted at high temperature can be reused in biodiesel production as a catalyst.