Showing papers on "Vegetable oil refining published in 2012"

Temperature dependence of density and viscosity of vegetable oils

Abstract: The straight use of vegetable oils as fuel in diesel engines entails adjusting several physical properties such as density and viscosity. By adequately heating the vegetable oil before entering the injection system, its physical parameters can reach values very close to that of diesel fuel. Consequently, by properly adjusting the temperature of vegetable oils used as fuel, it is possible to improve their combustion performance, thus avoiding premature engine aging due to incomplete burning. In this study the density and viscosity of several vegetable oils are studied within a wide variety of temperatures. The optimal range of temperatures at which each vegetable oil should operate in order to adjust its properties to those of automotive diesel and biodiesel is then found. Additionally an empirical relationship between the dependence of viscosity with density is presented. Thus, by means of the above-described relationship, through measuring the density of a given oil, its viscosity can be directly deduced.

Hydroconversion of Triglycerides into Green Liquid Fuels

Abstract: Due to the depletion of crude reserves and the increasing demand for clean hydrocarbon fuels the production of renewable materials-based fuels has emerged to solve at least partially this problem in the past decade and it is expected to continue [1,2]. Green fuels can be classified as naphtha, jet fuel, and diesel. In the case of green diesel, its increasing demand could reach 900 million tons by 2020 [3].

Liquid hydrocarbon fuels from jatropha oil through catalytic cracking technology using AlMCM-41/ZSM-5 composite catalysts

Abstract: Biofuels, the hydrocarbons less than C 18 , produced by catalytic cracking of nonedible vegetable oils are the potential source to battle energy demand and pollution. Among the non edible oils, jatropha is the apt candidate for the production of biofuel. Jatropha oil can be cracked catalytically over solid acid catalysts to yield liquid fuels with superior characteristics. We present here the hydrothermal syntheses of a microporous solid acid catalyst (HZSM-5 with Si/Al = 14), mesoporous materials (AlMCM-41) with varying Si/Al ratios (Si/Al = 18, 41, 72 and 95) and composite catalyst comprising HZSM-5 (as core) and varying coating percentages (5, 10 and 20%) of AlMCM-41 (as shell). All the synthesized catalysts were characterized by using XRD, BET N 2 sorption studies, ICP, TPD and SEM techniques. Herein we report the catalytic activities of all the synthesized catalysts towards the cracking of jatropha oil obtained at the optimized conditions of temperature – 400 °C, WHSV – 4.6 h −1 and reaction time – 1 h. Of all the mesoporous catalysts with varying Si/Al ratios, AlMCM-41 (Si/Al = 18) was found to be the most active catalyst as it converted 65% of jatropha oil yielding 39% of bioliquid fuel with 47% and 36% selectivities towards green diesel and green gasoline respectively. In the core–shell architecture of the composite catalyst, different % coatings of the best active mesoporous material (AlMCM-41, Si/Al = 18) over the best active microporous material (ZSM-5, Si/Al = 14) were done. AlMCM-41/ZSM-5 (25, 15, 10) showed remarkable performance in the conversion of jatropha oil (99%) yielding 70% of bioliquid fuel with very high selectivity (61%) towards green gasoline.

Production of Bio-Hydrogenated Diesel by Hydrotreatment of High-Acid-Value Waste Cooking Oil over Ruthenium Catalyst Supported on Al-Polyoxocation-Pillared Montmorillonite

Abstract: Waste cooking oil with a high-acid-value (28.7 mg-KOH/g-oil) was converted to bio-hydrogenated diesel by a hydrotreatment process over supported Ru catalysts. The standard reaction temperature, H2 pressure, liquid hourly space velocity (LHSV), and H2/oil ratio were 350 °C, 2 MPa, 15.2 h–1, and 400 mL/mL, respectively. Both the free fatty acids and the triglycerides in the waste cooking oil were deoxygenated at the same time to form hydrocarbons in the hydrotreatment process. The predominant liquid hydrocarbon products (98.9 wt%) were n-C18H38, n-C17H36, n-C16H34, and n-C15H32 when a Ru/SiO2 catalyst was used. These long chain normal hydrocarbons had high melting points and gave the liquid hydrocarbon product over Ru/SiO2 a high pour point of 20 °C. Ru/H-Y was not suitable for producing diesel from waste cooking oil because it formed a large amount of C5–C10 gasoline-ranged paraffins on the strong acid sites of HY. When Al-polyoxocation-pillared montmorillonite (Al13-Mont) was used as a support for the Ru catalyst, the pour point of the liquid hydrocarbon product decreased to −15 °C with the conversion of a significant amount of C15–C18 n-paraffins to iso-paraffins and light paraffins on the weak acid sites of Al13-Mont. The liquid product over Ru/Al13-Mont can be expected to give a green diesel for current diesel engines because its chemical composition and physical properties are similar to those of commercial petro-diesel. A relatively large amount of H2 was consumed in the hydrogenation of unsaturated C=C bonds and the deoxygenation of C=O bonds in the hydrotreatment process. A sulfided Ni-Mo/Al13-Mont catalyst also produced bio-hydrogenated diesel by the hydrotreatment process but it showed slow deactivation during the reaction due to loss of sulfur. In contrast, Ru/Al13-Mont did not show catalyst deactivation in the hydrotreatment of waste cooking oil after 72 h on-stream because the waste cooking oil was not found to contain sulfur-containing compounds.

Evaluation of the impacts of biodiesel and second generation biofuels on NO(x) emissions for CARB diesel fuels.

Abstract: The impact of biodiesel and second generation biofuels on nitrogen oxides (NO(x)) emissions from heavy-duty engines was investigated using a California Air Resources Board (CARB) certified diesel fuel. Two heavy-duty engines, a 2006 engine with no exhaust aftertreatment, and a 2007 engine with a diesel particle filter (DPF), were tested on an engine dynamometer over four different test cycles. Emissions from soy- and animal-based biodiesels, a hydrotreated renewable diesel, and a gas to liquid (GTL) fuel were evaluated at blend levels from 5 to 100%. NO(x) emissions consistently increased with increasing biodiesel blend level, while increasing renewable diesel and GTL blends showed NO(x) emissions reductions with blend level. NO(x) increases ranged from 1.5% to 6.9% for B20, 6.4% to 18.2% for B50, and 14.1% to 47.1% for B100. The soy-biodiesel showed higher NO(x) emissions increases compared to the animal-biodiesel. NO(x) emissions neutrality with the CARB diesel was achieved by blending GTL or renewable diesel fuels with various levels of biodiesel or by using di-tert-butyl peroxide (DTBP). It appears that the impact of biodiesel on NO(x) emissions might be a more important consideration when blended with CARB diesel or similar fuels, and that some form of NO(x) mitigation might be needed for biodiesel blends with such fuels.

Performance evaluation of a diesel engine fueled with methyl ester of castor seed oil

Abstract: Diesel engines are widely used as power sources in medium and heavy-duty applications because of their lower fuel consumption and lower emissions of carbon monoxide (CO) and unburned hydrocarbons (HC) compared with gasoline engines. Rudolf Diesel, the inventor of the diesel engine, ran an engine on groundnut oil at the Paris Exposition of 1900. Since then, vegetable oils have been used as fuels when petroleum supplies were expensive or difficult to obtain. With the increased availability of petroleum in the 1940s, research into vegetable oils decreased. Since the oil crisis of the 1970s research interest has expanded in the area of alternative fuels. The difficulties associated with using raw vegetable oils in diesel engines identified in the literature are injector coking, severe engine deposits, filter gumming problems, piston ring sticking, and injector coking and thickening of the lubricating oil. The high viscosity and low volatility of raw vegetable oils are generally considered to be the major drawbacks for their utilization as fuels in diesel engines. Castor methyl ester (CME) blends showed performance characteristics close to diesel. Therefore castor methyl ester blends can be used in CI engines in rural area for meeting energy requirement in various agricultural operations such as irrigation, threshing, indistries etc.

Biodiesel as an alternative fuel for direct injection diesel engines: A review

Abstract: Biodiesel is an alternative fuel to diesel engine that can replace or reduce the use of petroleum diesel. Biodiesel is derived from vegetable oils, animal fats, and waste cooking oils through transesterification reaction. This paper reviews the optimization of transesterification process for different varieties of biodiesel by considering the factors such as alcohols, fatty acid content, molar ratio of alcohols to oil, catalyst concentration, reaction temperature, and reaction time. The review also addresses various technical aspects of biodiesel usage in diesel engine to improve the cold flow properties, performance, combustion characteristics and reduce the emission characteristics, particularly nitric oxide and smoke compared to diesel through either modifying engine parameters like fuel injection pressure and timing or fuel modification by blending with alcohols, diesel, and metal based additives.

Green Oil Production by Hydroprocessing

Abstract: Owning to GHG emissions control and prospective future of biofuel, it is encouraged to look for a shift to alternate industrial feedstock and green processes to produce these chemicals from renewable biomass resources Besides hydrotreating bio-oil or crop oil to produce second generation bio-fuels, the bio-oil can be co-processed in various refining units and it also may lead to the production of green diesel, which is not only an opportunity but also a challenge for petroleum industry Green oil or green diesel can be produced by co-processing renewable diesel with petroleum oil in present hydroprocressing unit Many researches and works have been done on co-processing process and related catalyst in the hope of figuring out the mechanism and optimizing the co-processing technology with adding amounts vegetable oils or animal fats to the traditional petroleum refining process to produce green oil This is a literature review about green oil production by hydroprocessing and co-processing

Two steps alkaline transesterification of waste cooking oil and quality assessment of produced biodiesel.

Abstract: Biodiesel is an environmentally friendly renewable diesel fuel alternative. In Egypt, millions liters of waste cooking oil (WCO) are discarded annually into sewage systems, pollute water streams and adds to the cost of treating effluents. In an attempt to reduce the cost of biodiesel and pollution caused by WCO, this study aimed to investigate the feasibility of biodiesel production from WCO by applying two steps alkaline transesterification process using methanol, KOH as a catalyst and hot distilled water for purification. The produced biodiesel was physico-chemically characterized. From the results it was clear that the produced biodiesel was within the recommended standards of biodiesel fuel (r > 0.95) and met the criteria required to be a diesel substitute compared with the Egyptian petro-diesel fuel standards (r = 0.999).

Performance and Emission Studies of Castor Bean (Ricinus Communis) Oil Biodiesel and Its Blends with Diesel Fuel

Abstract: An experimental study was conducted to evaluate the use of various blends of castor (Ricinus Communis) oil methyl ester with diesel fuel. Performance and exhaust emissions of castor oil biodiesel with diesel fuel in a commercial compression ignition engine were presented in this study. Biodiesel produced from castor oil was blended with diesel fuel at the volumetric ratios of 5% (B5), 10% (B10), 25% (B25), 50% (B50), and 100% (B100). Fuel properties of castor oil methyl ester and its blends with diesel fuel were stated. The performance results showed that blends of castor oil methyl ester with diesel provided an increase on brake specific fuel consumption and a small decrease on brake power output. Compared with diesel fuel, diesel-castor oil methyl ester blends showed that while the carbon monoxide and carbon dioxide emissions became reduced; the oxides of nitrogen emissions observed higher than diesel fuel emission characteristics. Test results showed that B25 was determined as a suitable alter...

Experimental and Kinetic Modeling Study of 3-Methylheptane in a Jet-Stirred Reactor

Abstract: Improving the combustion of conventional and alternative fuels in practical applications requires the fundamental understanding of large hydrocarbon combustion chemistry. The focus of the present study is on a high-molecular-weight branched alkane, namely, 3-methylheptane, oxidized in a jet-stirred reactor. This fuel, along with 2-methylheptane, 2,5-dimethylhexane, and n-octane, are candidate surrogate components for conventional diesel fuels derived from petroleum, synthetic Fischer–Tropsch diesel and jet fuels derived from coal, natural gas, and/or biomass, and renewable diesel and jet fuels derived from the thermochemical treatment of bioderived fats and oils. This study presents new experimental results along with a low- and high-temperature chemical kinetic model for the oxidation of 3-methylheptane. The proposed model is validated against these new experimental data from a jet-stirred reactor operated at 10 atm, over the temperature range of 530–1220 K, and for equivalence ratios of 0.5, 1, and 2. S...

Emissions of acrolein and other aldehydes from biodiesel-fueled heavy-duty vehicles.

Abstract: Aldehyde emissions were measured from two heavy-duty trucks, namely 2000 and 2008 model year vehicles meeting different EPA emission standards. The tests were conducted on a chassis dynamometer and emissions were collected from a constant volume dilution tunnel. For the 2000 model year vehicle, four different fuels were tested, namely California ultralow sulfur diesel (CARB ULSD), soy biodiesel, animal biodiesel, and renewable diesel. All of the fuels were tested with simulated city and high speed cruise drive cycles. For the 2008 vehicle, only soy biodiesel and CARB ULSD fuels were tested. The research objective was to compare aldehyde emission rates between (1) the test fuels, (2) the drive cycles, and (3) the engine technologies. The results showed that soy biodiesel had the highest acrolein emission rates while the renewable diesel showed the lowest. The drive cycle also affected emission rates with the cruise drive cycle having lower emissions than the urban drive cycle. Lastly, the newer vehicle with the diesel particulate filter had greatly reduced carbonyl emissions compared to the other vehicles, thus demonstrating that the engine technology had a greater influence on emission rates than the fuels.

On the feasibility of producing hydrogen with net carbon fixation by the decomposition of vegetable and microalgal oils.

Abstract: The decomposition of vegetable and microalgal oils was herein analysed as a process of high interest for the production of both hydrogen and carbon, which potentially entails the advantage of attaining a negative CO2 balance through carbon fixation. The feasibility of a series of oil decarbonization systems was evaluated by means of energy and CO2 balances, which comprised not only the direct decarbonization process itself but also the cultivation and oil extraction stages. Three potential scenarios were assessed, embracing different options to meet the energy requirements of the systems. For each scenario, a wide range of case studies were evaluated, involving the use of rapeseed, sunflower, soybean, jatropha, Botryococcus braunii and Chlorella vulgaris oils as raw materials. Favourable energy and CO2 balances were found for a variety of crops in different scenarios. In particular, jatropha oil from high seed yield crops and rapeseed oil from high seed yield and high oil content crops were identified as the most promising biomass feedstocks for oil decarbonization since they led to net hydrogen production as well as to negative balances of CO2 emissions, therefore showing a carbon fixation effect. When compared to vegetable/microalgal oil transesterification to produce biodiesel, oil decomposition proved to be a more suitable alternative from a combined energy and environmental approach.

Comparison of Alternative Diesel Fuels with the Composition-Explicit Distillation Curve Method

Abstract: In recent years, environmental considerations, the potential for supply disruptions, and rising fuel prices have led to the development of alternative diesel fuels produced from nonpetroleum feedstocks. It is important to characterize the properties of these fuels in order to assess the degree of departure of the alternative fuels from the petroleum-derived fuels. One of the most important properties to use for this purpose is the volatility, as expressed by the distillation curve. In this paper, we present advanced distillation curve measurements of three prototype alternative diesel fuels and compare the distillation curve, composition, and combustion enthalpy to those of petroleum-derived diesel fuel. We studied two Fischer–Tropsch diesel fuels, one synthesized from coal-derived gas and one produced from natural gas, and one renewable diesel fuel composed of hydrotreated animal and vegetable fats. We found that the distillation curves of the three alternative diesel fuels are similar to those of petrol...

Study of droplet vaporization of various vegetable oils and blends of domestic fuel oil-cottonseed oil under different ambient temperature conditions

Abstract: In this work, the evaporation characteristics of different pure vegetable oils (cottonseed oil, jatropha oil, and rapeseed oil), domestic fuel oil (DFO) and blends of domestic fuel oil and cottonseed oil have been studied using the fibre-suspended droplet evaporation technique. The constants of evaporation of pure products were determined as well as the influence of the proportion of DFO fraction on the mechanisms of vaporization process of cottonseed oil in the temperature range of 578 K-917 K under atmospheric pressure. The results show that the DFO evaporates completely in the range of temperatures considered in contrast to vegetable oils that vaporize completely only for temperatures higher than or equal to 773 K. Above 873 K, the behaviour of vegetable oils becomes similar to a single component product and the d(2) law is respected. At a given temperatures range, constants of evaporation of the three vegetable oils are of the same order of magnitude. The results also show that blends of cottonseed oil and DFO vaporize following a sequential distillation mechanism: DFO is evaporating first, followed by a transient phase, and then cottonseed oil vaporizes following the same trends than observed for pure vegetable oils. For low percentages of cottonseed oil (<= 40%) in the mixture, formation of bubbles can be observed at the end of the process at 684 K. When the concentration of vegetable oil in the droplet increases, the mechanism of pure diffusion becomes predominant. (C) 2012 Elsevier Ltd. All rights reserved.

Production of olefins via steam cracking of vegetable oils

Abstract: Vegetable oils (in Europe particularly rapeseed) are the favoured raw material for production of methyl esters to be used as biodiesel. This paper discloses a possibility of their alternative utilization as crude oil substitute via vegetable oil steam cracking to produce short alkenes to be used in polyolefins production industry. During thermal decomposition under conditions matching those of gas-oil steam cracking (short residence time, temperature over 800 °C) vegetable oils form similar products as traditional crude-oil-based feedstocks. The yields of major pyrolysis products of various vegetable oils were determined using the apparatus employed previously to laboratory research of hydrocarbon pyrolysis and they were compared to yields obtained by cracking traditional feedstocks. Also the effects of hydrocarbon chain length and saturation of acyls forming the oils were analyzed in detail. The possibilities of processing vegetable oils by co-cracking in mixture with crude oil feedstocks are discussed and supported by experimental data.

Experimental Investigation of Cotton Seed Oil and Neem Methyl Esters as Biodiesel On Ci Engine

Abstract: In a modern day world alternative source of energy are given importance due to gradual depletion of fossil fuels reserves vegetable oils can be used as an alternative to diesel in CI engines. The use of vegetable oils in CI engine results in low CO and HC emissions compared to conventional diesel fuel. The present study covers the various aspects of biodiesels fuel derived from cottonseed oil. Cottonseed oil is converted to cottonseed oil methyl esters by transesterification process An experimental investigations were carried out on C.I.engine with Bio Diesel blends of cotton seed Methyl Esters and Neem Oil Methyl Esters .The engine used for the experiments was single cylinder Four Stroke water cooled, constant speed diesel engine . cotton seed Methyl ester (CSOME) and Neem oil methyl ester (NOME) are derived through transesterification process and parameters of transesterification were optimized. The blends of various proportions of the CSOME & NOME with diesel were prepared, analyzed and compared with diesel fuel, and comparison was made to suggest the better option among the bio diesel. Various Tests have been carried out to examine properties, performance of different blends (C05, C10, C15, and C20) of CSOME and NOME in comparison to diesel. From the experimental Results it is indicated that C20 have closer performance to diesel. However, its diesel blends showed reasonable efficiencies. From the experimental results it is observed that cotton seed methyl ester gives better performance compared to Neem methyl esters and also the emissions and smoke for these diesel blends are less as compare to the pure diesel.

Measurements and Modeling Study on a High-Aromatic Diesel Fuel

Abstract: The increasing cost of diesel fuel, potential for supply disruptions, and environmental concerns have resulted in a great deal of research to improve the performance and efficiency of diesel engines. This includes significant efforts in the reformulation of conventional diesel fuels and the development of renewable diesel fuels. An integral part of work on diesel fuels has been the measurement and modeling of the thermophysical properties of the fuels; this knowledge is critical to effective design and application. In this paper, we present the development of a model for thermodynamic and transport properties for a conventional diesel fuel based on our measurements of chemical composition, density, viscosity, and volatility. This information, along with the cetane number and heat of combustion, was used to develop surrogate mixture models. The models contain constituent fluids representative of those found in the fuel and were designed to represent thermophysical properties (density, viscosity, and volati...

Feedstocks for advanced biodiesel production.

Abstract: This chapter presents the most frequent vegetable-based feedstocks for biodiesel production. It introduces first generation biodiesel and focuses on second generation biodiesel with emphasis on low-cost raw materials. Vegetable oils from non-edible plants, frying oils and animal fats constitute the most extensively studied raw materials for second generation biodiesel. In this chapter, other raw materials such as soapstocks or oils for green diesel production are reviewed. Finally, feedstocks for advanced biodiesel production, such as microbial oils (also named single cell oils) or microdiesel are studied, as they are considered to be among the promising raw materials for third generation biodiesel production. The chapter finishes with a brief overview about the biorefinery concept.

Experimental Investigation of Performance of Diesel Engine Working On Diesel and Neem Oil Blends

Abstract: The depletion of oil resources as well as the environmental regulation has led to the development of alternate energy sources. In this present work the performance characteristics of a single cylinder diesel engine when fulled with blends of neem oil and diesel are evaluated. Experiments were conducted with different blends (B10&B20) of neem oil and diesel as various loads. The results show that the brake thermal efficiency of diesel is slightly higher at all loads followed by blends of neem oil and diesel, it has been established that 20% of neem oil biodiesel can be use as a substitute for diesel without any engine modification thus neem oil as non-edible oil can be a good renewable raw material for biodiesel production.