Cold Flow Properties Research Articles

Comparision of fuel properties of biodiesel fuels produced from different oils to determine the most suitable feedstock type

Energy, having primary importance in ensuring the prosperity and development of countries, has recently become one of the most strategic parameters in the international arena. Although there is no problem with oil and gas reserves for the next few decades, the issues such as searching for new alternative energy sources, producing and delivering them to consumers will be the most critical issues in energy sector. Today, almost all countries of the world (developed and developing) put in place new energy strategies to increase the share of alternative energy sources in their total energy consumption. Biodiesel is one of the most promising alternative energy sources. Biodiesel can be produced from a lot of different feedstocks such as vegetable oils, waste frying oils and fats, soapstock, algae, etc. However, produced biodiesel’s fuel properties significantly depend on the physico-chemical properties and fatty acid composition of its feedstock. In this study, methyl ester biodiesel fuels were produced by using the same transesterification reaction conditions from ten different vegetable oils including soybean, sunflower, corn, cottonseed, canola, olive, safflower, hazelnut, rapeseed, and algae. These oils’ fatty acid distributions and some critical fuel properties of biodiesel fuels obtained from these oils were detected and compared with each other to determine the best feedstock type for biodiesel production. The highest ester content value was measured for the biodiesel fuels produced from algae (98.7%) and olive oil (98.6%). In addition, cetane numbers of these two biodiesels were the highest (59 for algae biodiesel and 58 for olive oil biodiesel). The best cold flow properties were determined for biodiesel fuels obtained from algae, corn, and canola oils with the cold filter plugging point (CFPP) values of −14 °C, −13 °C and −13 °C, respectively.

Optimization of a diesel engine calibration for operating with a residual glycerol-derived biofuel

The new European directive for the promotion of renewable energy mandates an increase in the share of advanced and waste-based biofuels in the transport sector. In this study, an advanced glycerol-derived biofuel was used as a component of a ternary blend, denoted as o·bio®. This blend included 27.4 %v/v of fatty acid glycerol formal ester, 69.6 %v/v of fatty acid methyl ester and 3 %v/v of acetals obtained as a by-product of the fatty acid glycerol formal ester production process (which were proved to improve cold-flow properties). Finally, o·bio® was blended with diesel fuel at a content of 20 %v/v. Two operating conditions based on usual driving modes were selected, where the engine calibration could be re-optimized after the change of fuel, corresponding to vehicle velocities of 50 and 70 km/h. Since the main effect of the blend used is to reduce particulate matter emissions, exhaust gas recirculation was increased and injection was delayed, so that the initial benefits in particulate matter emissions could be re-distributed into benefits in both particulate matter and nitrogen oxides (NOx) emissions. From a combined analysis of the particulate matter–NOx trade-off and trying to limit the negative effect of delaying injection on fuel consumption, the final proposal was to set an additional 6% exhaust gas recirculation at 50 km/h and an additional 3% exhaust gas recirculation at 70 km/h, while delaying injection 2 °CA after top dead center at both vehicle operating conditions with respect to the original calibration. The use of the blend along with the optimization of the engine calibration is expected to reduce particulate matter and NOx emissions by around 50% with a vehicle speed condition of 50 km/h and to reduce particulate matter and NOx emissions by around 30% and 40% at 70 km/h with respect to diesel fuel emissions.

Correlating the Cold Filter Plugging Point to Concentration and Melting Properties of Fatty Acid Methyl Ester (Biodiesel) Admixtures

Biodiesel is a renewable alternative diesel fuel made from plant oils, waste cooking greases and animal fats. Its’ most common form is fatty acid methyl esters (FAME) from transesterification of lipids and methanol. Biodiesel has physical properties that compare well with conventional diesel fuel (petrodiesel). However, biodiesel has poor cold flow properties that must be monitored in cold weather. In this work, three correlation models are introduced that accurately calculate the cold filter plugging point (CFPP) of biodiesel. The models were developed using measured CFPP data from neat (unblended) biodiesel fuels and 24 binary biodiesel admixtures. The biodiesel fuels studied were from canola, palm and soybean oils and yellow grease (CaME, PME, SME and YGME). The solid-liquid equilibrium (SLE) model required accurate concentration, melting point (MP) and enthalpy of fusion (ΔHfus) data for each FAME species in the mixture. These data were used to infer the SLE phase transition temperature (TSLE) of the ...

Determination of Fuel Properties of Some Alcohols (Bioethanol, Butanol), Biodiesel and Diesel Mixtures Obtained from Anchovy (Engraulis encrasicolus) Oil

In this study, some alcohols (bioethanol, butanol) are mixed with different amounts in volume (M 100 , B 100 , M 75 B 20 E 5 , M 70 B 20 E 10 , M 65 B 20 E 15 , M 75 B 20 BÜ 5 , M 70 B 20 BÜ 10 and M 65 B 20 BÜ 15 ) some physical and chemical fuel properties of diesel, biodiesel and obtained alcohol + biodiesel + diesel blend fuels (Density, Kinematic viscosity, Flash point, Water content, Copper strip corrosion, Cloud point, Pour point, Cold filter block point (SFTN), The thermal value) was determined.According to the results of the research, it was observed that the physical and chemical fuel properties of biodiesel and blended fuels were within the standard fuel properties. The cetane number of M 65 B 20 E 15 fuels was 12% lower than the diesel standard (TS 3082 EN 590). In addition, when cold flow properties were examined, it was determined that ethanol and butanol added to fuels contributed positively.

Effect of winterization and plant phenolic-additives on the cold-flow properties and oxidative stability of Karanja biodiesel

Poor stability and low-temperature operability are among the major hurdles in the commercialization of biodiesel. The presence of polyunsaturated fatty acid esters renders the fuel susceptible to oxidative attack while the long-chain saturated components limit its utility under low-temperature conditions. In this study, an attempt was made to improve these properties of Karanja biodiesel. Karanja biodiesel synthesized via a two-step alkali-catalyzed process exhibited poor stability and cold-flow properties. Karanja biodiesel was winterized to limit the content of long-chain saturates, and it had a favorable effect on the cloud and pour point of the fuel. Removal of long-chain saturated components led to an enrichment of the fuel in unsaturated fractions, and as a result, the stability of the fuel further deteriorated. For improving, the stability of the fuel T. cordifolia stem extract rich in phenolic constituents was added to winterized biodiesel. The combined treatment of winterization and phenolic-rich extract (1000 ppm) had a pronounced effect on fuel quality as it led to a reduction in the cloud (by 7 °C) and pour point (by 6 °C) and substantially improved the stability of the fuel under accelerated oxidative test conditions. The ASTM D6751, IS 15607, and EN 14214 specifications for the minimum induction period for blendstock biodiesel were satisfied. Thus, coupling the use of winterization and natural antioxidants offers novel opportunities in improving the fuel properties and acceptability of biodiesel in an efficient, economical, and environment-friendly manner.

Characterization of the Physicochemical Property of Blend of Butanol and Octanol with Biodiesel

Energy is the major concern around the world not because it is limited availability of petroleum fuel but also due to its environmental effects, greenhouse gas emissions and ozone layer depletion. The compression ignition engine widely used in the agriculture, transportation, electric generation sector which mainly driven by fossil diesel. To counter the cause produce by fossil diesel use and its limited resources, bio-derived fuel may play a major role to fulfill the requirement. But, it has been observed that higher viscosity of biodiesel leads to poor atomization and improper mixing of fuel with air. The poor Combustion, higher viscosity, higher emission of NOx, low break thermal efficiency of biodiesel, the high cost of production are the main impediment in the preferment of the use of bio-diesel. To mitigate the problem of use of biodiesel blending of higher alcohol in biodiesel may offer a potential solution. Hence in this study Jatropha biodiesel has been blended with n-butanol and n-octanol alcohol by volume 10%, 20%, and 30%. i.e. JME90B10, JME80B20, JME70B30, JME90O10, JME80O20, JME70O30 and evaluate the physicochemical properties i.e. Kinematic viscosity, calorific value, cetane index, cold flow property and oxygen stability as per ASTM standard and compare with diesel and biodiesel. However, blends have a higher viscosity than diesel. But this fuel is bio-degradable in nature, help to diminish carbon footprint and has low emission outlines as compared to petroleum diesel. Usage of a combination of bio-fuel will allow a balance to be sought between agriculture, industrialization, transportation and the environment. GC-MS analysis of JME show 29.64% saturated acid and 69.25% of mono unsaturated acid. The properties of biodiesel depend upon the variation of acid percentage. Overall property of blend comparable with fossil diesel it may substitute the diesel.

Harvesting Scenedesmus obliquus via Flocculation of Moringa oleifera Seed Extract from Urban Wastewater: Proposal for the Integrated Use of Oil and Flocculant

The objectives this study were to examine the integrated use of oil–coagulant for the direct extraction of coagulant from Moringa oleifera (MO) with 5% and 10% (NH4)2SO4 extractor solution to harvest Scenedesmus obliquus cultivated in urban wastewater and to analyze the oil extracted from MO and S. obliquus. An average content of 0.47 g of coagulant and 0.5 g of oil per gram of MO was obtained. Highly efficient algal harvest, 80.33% and 72.13%, was achieved at a dose of 0.38 g L−1 and pH 8–9 for 5% and 10% extractor solutions, respectively. For values above pH 9, the harvest efficiency decreases, producing a whitish water with 10% (NH4)2SO4 solution. The oil profile (MO and S. obliquus) showed contents of SFA of 36.24–36.54%, monounsaturated fatty acids of 32.78–36.13%, and polyunsaturated fatty acids of 27.63–30.67%. The biodiesel obtained by S. obliquus and MO has poor cold flow properties, indicating possible applications limited to warm climates. For both biodiesels, good fuel ignition was observed according to the high cetane number and positive correlation with SFA and negative correlation with the degree of saturation. This supports the use of MO as a potentially harmless bioflocculant for microalgal harvest in wastewater, contributing to its treatment, and a possible source of low-cost biodiesel.

Excellent Properties of Dimer Fatty Acid Esters as Biolubricant Produced by Catalyst‐ and Solvent‐Free Esterification

AbstractCurrently most technologies available to produce esters require acid or base catalysts for esterification or transesterification reactions. Production of dimerate esters (DE) exhibiting potential as a biolubricant for low temperature applications using catalyst‐ and solvent‐free approaches is presented in this article. Hydrogenated C36dimer acid and alcohol are reacted under the following conditions: dimer acid/alcohol (1:4.5 molar ratio), 150–200 °C, 24 h, 3Å molecular sieve (15% w/w). The performances of four DE species—dibutyl, dihexyl, di‐(2‐ethylhexyl), and dioctyl dimerate—as lubricant base stocks are evaluated by kinematic viscosity, viscosity index, cloud and pour point (cold flow properties) as well as oxidative stability, and compared with commercial synthetic lubricant base stock and DE, Radialube 7121. High viscosity indexes ranging between 129 and 138 are observed for the synthesized DEs, which are comparable with two commercial base stock, polyalpha olefin (PAO), and polyolester (POE). Significantly low pour point, less than −42 °C, is observed for di‐(2‐ethylhexyl) dimerate attributed to the branching of the side chain. The DEs are categorized as ISO VG 68 based on their viscosity according to ISO 3448 classification and show potential as biolubricant with high viscosity index and excellent cold flow properties.Practical Applications: DFAE obtained have high potential to be used as lubricant base stock for equipment and machinery operating at extremely low temperature.

Estimation of cold flow properties of biodiesel using ANFIS-based models

ABSTRACT Biodiesel fuel tends to freeze at higher temperatures when compared with the traditional diesel fuel based on petroleum. Characterization and improvement of its poor cold flow properties (CFP) including cloud point (CP), pour point (PP), and cold filter plugging point (CFPP) have become one of the major challenges among researchers. The aim of the study was to develop a methodology to predict the three CFP of a biodiesel sample based on the fatty acid composition of its feedstock. CP, PP and CFPP prediction models based on Adaptive Neuro-Fuzzy Interference System (ANFIS) were developed. Saturated, monosaturated and polyunsaturated fatty acid contents were used as input variables. Seventy-five data sets including fatty acid contents of feedstocks and CFP of their biodiesels were used during training and verification stages. Biodiesel samples were produced from six different feedstocks either by base-catalyzed transesterification or by supercritical methanol transesterification methods in order to inspect the accuracy of the models. CFP of biodiesel samples were determined following the EN and also ASTM standards. It was noted that the CFP estimated by the ANFIS models were in close agreement with the measured values. The R2 values were found as 0.981, 0.985, and 0.981 for CP, PP, and CFPP, whereas the prediction performances of the models in terms of RSME were 1.066, 1.160, and 1.061, respectively. It was noteworthy that the present ANFIS models provided closer estimations than those models reported previously.

Branched Bio-Lubricant Base Oil Production through Aldol Condensation.

Currently, lubricant base oils are derived from petroleum, a nonrenewable feedstock that contributes to greenhouse gas emissions. Bioderived, renewable lubricant base oils can mitigate environmental challenges and offer superior cold flow properties by incorporating branches to the base oil's hydrocarbon backbone with an appropriate synthetic strategy. A strategy was developed to synthesize branched alkanes for lubricant base oil in two steps from 12-tricosanone, obtained from bioderived fatty acids, and furfural, obtained from lignocellulosic biomass. The reaction pathway involves carbon-carbon coupling through aldol condensation followed by hydrodeoxygenation (HDO). Various solvents (non-polar, aprotic and polar, protic) and reaction conditions were screened to achieve a maximum yield of 94.3 % of aldol condensation products, containing the majority of a C33 furan (79.5 %) followed by a C28 furan (14.8 %). Subsequent HDO of aldol condensation products over an Ir-ReOx /SiO2 catalyst produced lubricant-ranged branched alkanes (C28 and C33 ) with 61.4 % yield and small fractions (<11 %) of alkanes with carbon numbers between C15 and C10 . The viscous properties of the produced bio-lubricant base oil were comparable to commercial petroleum-derived Group III and Group IV base oils. This approach serves as a potential stepping-stone to replace petroleumderived base oils and, in turn, reduce greenhouse gas emissions associated with current lubricant production.

Effect of Biodiesel Mixture Derived from Waste Frying-Corn, Frying-Canola-Corn and Canola-Corn Cooking Oils with Various ‎Ages on Physicochemical Properties

Waste frying, corn and canola cooking oil biodiesels were produced through the transesterification ‎process and their properties were measured. Three different mixtures of biodiesel with the same blending ratio, namely, WCME1 (frying-corn biodiesel), WCME2 (frying-canola-corn biodiesel) and WCME3 (canola-corn biodiesel), were prepared. The effect ‎of ‎blending ‎biodiesel with various ages ‎‎(zero months (WCME3), eight months (WCME1), and 30 months (WCME2)) on kinematic ‎viscosity and‎ density was investigated under varying temperature and volume fraction. It was found that the kinematic viscosity of WCME2 remained within the ranges listed in ASTM D445 (‎1.9–6.0‎ mm2/s) and EN-14214‎ (‎3.5–5.0‎ mm2/s) at 30 months. It was also observed that both viscosity and density decreased as the temperature increased for each fuel sample. In order to improve the cold flow properties of the samples, the Computer-Aided ‎Cooling Curve Analysis (CACCA) technique was used to explore the crystallization/melting ‎profiles of ‎pure ‎methyl biodiesel as ‎well their blends. The results show that pure WCME2 has the lowest cold flow properties compared to other samples. Furthermore, 10 ‎correlations ‎were developed, tested and compared with generalized ‎correlations for the ‎estimation of the ‎viscosity and densities of pure biodiesels and their ‎blends. These equations depend on the temperature and volume fraction of pure components as well as the properties of the fuel.

EMM-17, a New Three-Dimensional Zeolite with Unique 11-Ring Channels and Superior Catalytic Isomerization Performance.

A new catalytically active zeolite, designated EMM-17 (ExxonMobil Material-17), with a three-dimensional (3D) 11 × 10 × 10-ring topology has been discovered from high throughput experiments while evaluating a family of new organic structure directing agents (OSDAs), 1-alkyl-4-(pyrrolidin-1-yl)pyridin-1-ium hydroxide. The framework structure was determined by model building techniques and confirmed by diffraction calculations. The EMM-17 structure is a random intergrowth of two polymorphs which have a 3D arrangement of intersecting 11 × 10 × 10-ring pores. EMM-17 is stable to calcination to remove the OSDA and can be reproducibly synthesized in the presence of fluoride using common, inexpensive reagents over a wide Si/Al range from 15 to infinity, enabling the catalyst acidity to be tailored to almost any petrochemical application. Unlike OSDAs for many new zeolite structures, the OSDAs for EMM-17 are prepared in one simple alkylation step, making EMM-17 an easy to prepare, highly accessible, catalytically active zeolite. Zeolites containing odd numbered channel sizes are rare, and this is the first confirmed example of a 3D 11-ring aluminosilicate zeolite with a pore size in between those of the commercially important 10- and 12-ring zeolites such as ZSM-5 and Zeolite-Y, respectively. Catalysts prepared from EMM-17 exhibit significantly higher activity for catalytic isomerization with no loss in selectivity than current state of the art catalysts. Catalytic isomerization of linear to branched alkanes is a critical component of commercial dewaxing, allowing for the improvement of cold flow properties of hydrocarbon fuels and lubricants through selective hydroisomerization of normal paraffins.

Comparative evaluation of lubricant properties of biodegradable blend of coconut and mustard oil

Abstract The vegetable oils are preferred over mineral oil as lubricating base oil due to their high biodegradability, renewability and low toxicity. Among vegetable oils, coconut oil as a lubricant exhibits low coefficient of friction at metallic interfaces but high wear rate and pour point compared to mineral oils, limits its application as a commercial lubricant. Mustard oil exhibits better wear resistance. In the present work, the saturated coconut oil was blended with unsaturated mustard oils by varying volume (%) of mustard oil from 10 to 50%. The composition of saturated and unsaturated fatty acids present in the blend was analysed by using gas-chromatograph mass-spectroscopy analyzer. The thermal and oxidative stability tests were performed on the blend using thermogravimetric analysis and differential scanning calorimetry. The physicochemical, thermal, rheological and tribological (using four-ball tester) analyses of the blended oil were carried out and the corresponding properties were compared with those of coconut oil, mustard oil and mineral oil (SAE20W40). The results showed that the tribological performance (in terms of wear) and cold flow properties (in terms of pour point) of the blends were superior to that of coconut oil and the blend (50%) exhibited the best performance. The wear scar diameter and pour point of the blend (50%) were 0.486 mm and −11.6 °C with a reduction of 18.45% and 159.7%, respectively, with respect to those of coconut oil. Compared with coconut oil the kinematic viscosity of the blend (50%) demonstrated an enhancement of 18.18% with a value of 32.88 mm2/s. The thermo-oxidative stability (in terms of on-set temperature) of the blend (50%) was better than that of coconut oil. Also, the friction and wear of the blended oil (50%) were lower than that of mineral oil. As a lubricant, the blend (50%) is the best biodegradable alternative for mineral oil for cleaner production.

Reaction kinetics analysis of branched-chain alkyl esters of palmitic acid and cold flow properties

Preparation of methyl palmitate, isopropyl palmitate, isobutyl palmitate, and isoamyl palmitate was carried out using pyridine n-butyl bisulfate ionic liquid as catalyst in a self-designed reactor to catalyze esterification reaction of palmitic acid with methanol, isopropanol, isobutanol, and isoamyl alcohol, respectively. According to the single-factor experimental results, an orthogonal test of four factors and three levels was carried out for branched-chain alkyl esters of palmitic acid under different reaction time, reaction temperature, and catalyst dosage. Verification test was conducted under the optimal conditions, and the conversion in all the cases was up to 97%. Analysis of the reaction kinetics of methyl palmitate, isopropyl palmitate, isobutyl palmitate, and isoamyl palmitate was carried out by the integral method. Reaction order, frequency factor, activation energy, and reaction kinetic model were determined. Compared to methyl palmitate, the kinematic viscosity of the branched-chain alkyl esters of palmitic acid was slightly higher; however, the solidifying point (SP) and cold filter plugging point (CFPP) decreased with increasing degree of branched-chain. The CFPP reduced by up to 15 °C. Therefore, the use of branched-chain alcohol instead of methanol ester exchange descaling method can effectively reduce the SP and CFPP of biodiesel to improve its cold flow properties.

Multiple-trait selection of soybean for biodiesel production in Brazil

Soybean (Glycine max (L.) Merrill) is an important source of oil for biodiesel production in Brazil. However, the traits related to oil content and fatty acid profile are not targeted by soybean breeding programs. Developing methods to increase oleic and reduce linolenic fatty acid content within soybean genotypes will increase the use of soybeans for food and feed, as well as biodiesel production. Biodiesel produced with high polyunsaturated fatty acids (PUFAs) content has a high tendency to undergo oxidation, making storage difficult and overall quality reduced. On the other hand, oils with high levels of monounsaturated fatty acids (MUFAs) are preferred for biodiesel production because oxidation is not increased, improve cold flow properties significantly and nitrogen oxide emissions are decreased. In addition, soybean oil with high concentration of PUFAs causes low oxidative stability, resulting in rancidity, a rapid decline of optimal flavor and reducing storage time of manufactured food products. 242 recombinant inbred lines (RILs) were evaluated in six locations in Brazil for grain yield, oil content, oil production, and fatty acid composition. A multi-trait index based on factor analysis and ideotype-design (FAI-BLUP index) was applied to identify genotypes best related with the ideotype for biodiesel production. This method is based on mixed models, with genotype and environment effects being considered as random and fixed, respectively. In addition, the best linear unbiased prediction (BLUP) method was used to predict the genetic values. Six RILs outperformed both parents and can be selected as genotypes more suitable for biodiesel production. Genetic selection reduced linolenic fatty acid content by 14%. Results indicated the presence of genetic variability for fatty acid composition. The significant increases in oleic and reductions in linolenic contents may be easily achieved with the introduction of mutant FAD2-1A and FAD2-1B genes through breeding programs or biotechnological strategies.

Synthesis and physicochemical properties of novel lauric acid capped estolide esters and amides made from oleic acid and their evaluations for biolubricant basestock

Vegetable oils have been used as environmentally friendly biolubricants because of their inherent biodegradability, good lubricity, higher viscosity index and low evaporative loss. However, their use is limited due to significantly poor cold flow properties and inferior oxidative stability. This paper presents an approach to modify vegetable oil derivatives namely oleic acid to yield biolubricant with good cold flow properties and oxidation stability. Oleic acid was converted to polyhydroxy estolide through reaction with only hydrogen peroxide, which is considered a ‘green’ oxidant. The synthesized polyhydroxy estolide was further reacted with appropriate amount of lauric acid to end-cap its hydroxy groups, which yielded lauric acid capped estolide as the product. Subsequently, the prepared lauric acid capped estolide was reacted with branched and straight chain alcohols as well as secondary amines to afford estolide esters and amides. In general, most of the prepared samples showed improved cold flow properties as compared to vegetable oil-based lubricants, where the best pour point (−41 °C) was achieved by 4-methyl-2-pentyl estolide ester. Meanwhile, estolide amides exhibited the best oxidative stability among samples evaluated with an oxidation onset temperature of 205 °C, which is significantly higher than vegetable oil-based lubricants. Generally, the oxidative stability, viscosity index and anti-wear properties of prepared estolide esters and amides were found to be comparable to the properties of commercial samples used as benchmark.

Fuels properties, characterizations and engine and emission performance analyses of ternary waste cooking oil biodiesel–diesel–propanol blends

Application of biodiesel synthesized from waste-based raw materials with numerous solvents (higher chain alcohols) in diesel engines is a topic of great interest. This article examines the effect of biodiesel–diesel–propanol ternary blends. Physio-chemical properties, fatty acids composition (FAC), FT–IR, TGA, DSC, NMR along with some selected engine and emissions performance parameters were examined. Biodiesel was produced from waste cooking oil and exhibits excellent FAC that yields kinematic viscosity, cetane number, oxidation stability, higher heating value and iodine value of 3.93 mm2/s, 58.88, 7.43 h, 39.45 MJ/kg and 64.92 g/100 g. Propanol blended biodiesel depicted an affirmative improvement in cold flow properties and decremented density. FT–IR and NMR results confirms the existence of biodiesel–diesel–propanol and prove their qualities as reliable methods. DSC and TGA results confirm that propanol reduces the onset and crystallization temperatures of the blends. Engine and emissions performance revealed that propanol addition further increased brake specific energy consumption (BSEC) and brake specific fuel consumption (BSFC) and reduced carbon monoxide (CO), exhaust gas temperature (EGT), nitrogen oxides (NOx) and smoke. This study proves the feasibility of the ternary blends with rewarding benefits in cold flow properties and densities besides acceptable engine and emissions performance results.

Kinetics and the fluidity of the stearic acid esters with different carbon backbones

Abstract In this work, stearic acid esters were prepared using [HPY][HSO4] ionic liquids as catalysts and different kinds of alcohols and stearic acid as reactants in a self-designed reactor. Catalytic esterification, kinetics analysis and low temperature fluidity of the esters were studied. Through single-factor experiment, the optimal reaction conditions were determined for methyl stearate, ethyl ester, propyl ester, butyl ester, and amyl ester. The conversion rates under the optimized conditions were all above 97%. The kinetics of the reaction process of all five esters was analyzed by the integral method, and the activation energy, pre-exponential factor and kinetic model were obtained for the five esters. Finally, the low temperature fluidity of all esters was tested and the best value was observed for amyl alcohol. Therefore, these esters would be useful additives for reducing the condensation and cold filter plugging points of biodiesel, thus improving the cold flow properties of biodiesel.

Pretreatment methods to improve the kinematic viscosity of biodiesel for use in power tiller engines

Biodiesel is an environmentally friendly fuel that can replace diesel in compression ignition engines without changing the engine structure. Biodiesel is typically manufactured from vegetable oils and animal fats, which give the fuel its oxidation stability and cold-flow properties, respectively. However, the kinematic viscosity of biodiesel can cause engine performance problems such as incomplete combustion and sludge formation due to insufficient fuel atomization. To address these problems, in this study, a pretreatment technology that lowers the kinematic viscosity of biodiesel made from blended animal fat and vegetable oil was developed. The results of application of the pretreated fuel to a single-cylinder power tiller engine indicated that it produced 88.3–99.8 % of the brake power produced by conventional diesel. In addition, although the pretreated biodiesel exhaust included increased amounts of nitrogen oxides and carbon dioxide emissions, the proposed fuel also decreased the amounts of hydrocarbon and carbon monoxide emissions compared with conventional diesel emissions.

P-3-10 Effective parameters on cold-flow properties of biodiesel and fossil diesel blends

P-3-10 Effective parameters on cold-flow properties of biodiesel and fossil diesel blends