Biodiesel production from soybean and Jatropha oils using cesium impregnated sodium zirconate as a heterogeneous base catalyst

Cesium modified sodium zirconate (Cs-Na₂ZrO₃) was prepared by ionic exchange from sodium zirconate (Na₂ZrO₃), which was synthesized via a solid state reaction. Both ceramics, i.e., pristine Na₂ZrO₃ and the Cs-Na₂ZrO₃, were used as basic heterogeneous catalysts in biodiesel production. Soybean and Jatropha oils were used as triglyceride sources for transesterification reactions. Parameters, such as catalyst concentration (between 0.5 and 3 wt%), reaction time, different methanol/vegetable oil molar ratios, and temperature of the reaction, were evaluated. The cesium cation influence was evaluated from the basic transesterification reactivity. The results showed that the introduction of cesium significantly modified the catalytic activity in biodiesel production. Cs enhanced the reaction kinetics in obtaining biodiesel and reduced the reaction time in comparison with pristine Na₂ZrO₃. The results showed that Cs-Na₂ZrO₃ as a basic heterogeneous catalyst exhibited the best fatty acid methyl esters (FAME) conversion for soybean oil (98.8%) at 1 wt%, 30:1 methanol/oil ratio, 65 °C, and 15 min. The best conditions for Jatropha oil (90.8%) were 3 wt%, 15:1 methanol/oil ratio, 65 °C, and 1 h. The impregnation of Na₂ZrO₃ with cesium represents a very exciting alternative heterogeneous base catalyst for biodiesel production.     

A green catalyst for biodiesel production from jatropha oil: Optimization study

In this study, a simple and solvent-free method was used to prepare sulfated zirconia-alumina (SZA) catalyst. Its catalytic activity was subsequently investigated for the transesterification of Jatropha curcas L. oil to fatty acid methyl ester (FAME). The effects of catalyst preparation parameters on the yield of FAME were investigated using Design of Experiment (DOE). Results revealed that calcination temperature has a quadratic effect while calcination duration has a linear effect on the yield of FAME. Apart from that, interaction between both variables was also found to significantly affect the yield of FAME. At optimum condition; calcination temperature and calcination duration at 490 °C and 4 h, respectively, an optimum FAME yield of 78.2 wt% was obtained. Characterization with XRD, IR and BET were then used to verify the characteristic of SZA catalyst with those prepared using well established method and also to describe the catalyst characteristic with its activity.     

Fatty acid methyl ester production from wet microalgal biomass by lipase-catalyzed direct transesterification

The aim of this work was to optimize the production of fatty acid methyl ester (FAME, biodiesel) from wet Nannchloropsis gaditana microalgal biomass by direct enzymatic transesterification. This was done in order to avoid the high cost associated with the prior steps of drying and oil extraction. Saponifiable lipids (SLs) from microalgal biomass were transformed to FAME using the lipase Novozyme 435 (N435) from Candida antarctica as the catalyst, and finally the FAME were extracted with hexane. t-Butanol was used as the reaction medium so as to decrease lipase deactivation and increase mass transfer velocity. A FAME conversion of 99.5% was achieved using wet microalgal biomass homogenized at 140 MPa to enhance cell disruption, a N435:oil mass ratio of 0.32, methanol added in 3 stages to achieve a total of 4.6 cm³ g⁻¹ of oil and 7.1 cm³ g⁻¹ oil of added t-butanol, with a reaction time of 56 h. The FAME conversion decreased to 57% after catalyzing three reactions with the same lipase batch. This work shows the influence of the polar lipids contained in the microalgal biomass both on the reaction velocity and on lipase activity.     

Biodiesel production in a serpentine minireactor—Effect of flow distribution

The present work aims to find out the influence of flow pattern on pressure drop and fatty acid methyl ester (FAME) yield in a reactive system. Experiments are carried out with Jatropha oil and methanol by using potassium hydroxide (KOH) as catalyst for biodiesel production in two serpentine minireactors made of glass capillary of 2‐mm internal diameter. One is having a circular cross section, and the other is annulus. Slug flow, slug with droplet flow, and dispersed flow are observed in both the reactors. Effects of flow distribution on pressure drop and FAME yield have been studied. FAME yield of 98.5% is observed in both reactors for a molar ratio 20 (methanol to Jatropha oil), and the time for this yield in the first reactor is 16.6 minutes and that for the second reactor is 7.7 minutes. Higher yield also resulted in lower pressure drop due to lower viscosity of biodiesel in comparison with oil.     

Screening,optimization and kinetics of Jatropha curcas oil transesterification with heterogeneous catalysts

This work investigates the production of fatty acid methyl esters (FAME) from Jatropha curcas oil using a variety of heterogeneous catalysts: resins, zeolites, clays, hydrotalcites, aluminas and niobium oxide. For this purpose, a catalyst screening was first conducted in a batch reactor at the following operating conditions: oil to methanol molar ratio of 1:9, 6 h of reaction, 5 wt% catalyst, at 333 and 393 K. From the screening step, KSF clay and Amberlyst 15 catalysts were selected to carry out a 2³ full factorial central composite rotatable design so as to elucidate the effects of process variables on FAME yield. The optimum reaction conditions for both catalysts were found to be oil to methanol molar ratio of 1:12, 5 wt% of catalyst, 433 K and 6 h of reaction with a FAME yield of about 70 wt%. A kinetic study was then experimentally performed and a semi-empirical model was built to represent the experimental data. Finally, catalyst re-utilization in five successive batch experiments was evaluated at the optimized conditions.     

Biodiesel preparation from Jatropha oil catalyzed by KF/Red mud catalyst

Biodiesel preparation from Jatropha oil catalyzed by KF/Red mud (KF/RM) was studied. The optimum values of parameters for preparation of Jatropha oil biodiesel were obtained. The conversion rate of transesterification reached 92.2% under the optimum conditions, and the used KF/RM could be regenerated. Catalyst characterization showed that KOH and KFeF₄ were produced in KF/RM catalyst, which was crucial for the transesterification of Jatropha oil with methanol. Red mud was a good support to prepare KF-loaded catalyst, and prepared KF/RM was an excellent catalyst for biodiesel synthesis from Jatropha oil via transesterification reaction.     

Improving the yield of Jatropha curcas's FAME through sol–gel derived meso-porous hydrotalcites

The conversion of fatty acid methyl ester (FAME) from triglycerides using heterogeneous catalysis has gained increasing interest due to the prospect of increased yield at reduced operating costs and reaction conditions. In this paper, meso-porous hydrotalcite was used to catalyze jatropha oil into FAME with relatively higher yield at atmospheric pressure and relatively low reaction temperature. The molar ratio of methanol to oil required was relatively low and the conversion was completed within few hours of reaction time. The reaction was promoted when moderate calcination temperature was applied, the disordered structure of the catalyst was maintained, counterbalance anions was removed, and phase transitions within the oxide lattice was induced. Despite the observed deactivation during successive reaction cycles due to adsorption of residual triglycerides, the catalyst performance was restored effectively by air-re-calcination.     

Transesterification of canola oil as biodiesel over Na/Zr-SBA-15 catalysts: Effect of zirconium content

A series of mesoporous Zr-SBA-15-supported Na catalysts was prepared and applied to the heterogeneous catalysis of canola oil transesterification. The effects of Si/Zr ratio, reaction time, and percentage of Na loading on the conversion to fatty acid methyl esters (FAME) were studied. The dependence of the textural structure and chemical properties of Zr-SBA-15 supports on Zr content was investigated using small-angle X-ray diffraction, Brunauer–Emmett–Teller analysis, transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy. The results obtained from FTIR and TEM indicate that the incorporation of Zr atoms into the SBA-15 structure facilitated the formation of Brönsted acid sites and decreased the particle size of Na species. Catalysts with a higher Zr content enhanced the FAME yield. The optimum conditions determined were as follows: reaction temperature of 70 °C, 15 wt.% Na, reaction time of 6 h, and 12% catalyst content (wt.% oil) with a methanol/oil molar ratio of 6:1. The optimum conditions resulted in a FAME yield of up to 99%.     

Biodiesel production from mixed soybean oil and rapeseed oil

The biodiesel (fatty acid methyl esters, FAME) was prepared by transesterification of the mixed oil (soybean oil and rapeseed oil) with sodium hydroxide (NaOH) as catalyst. The effects of mole ratio of methanol to oil, reaction temperature, catalyst amount and reaction time on the yield were studied. In order to decrease the operational temperature, a co-solvent (hexane) was added into the reactants and the conversion efficiency of the reaction was improved. The optimal reaction conditions were obtained by this experiment: methanol/oil mole ratio 5.0:1, reaction temperature 55 °C, catalyst amount 0.8 wt.% and reaction time 2.0 h. Under the optimum conditions, a 94% yield of methyl esters was reached ∼94%. The structure of the biodiesel was characterized by FT-IR spectroscopy. The sulfur content of biodiesel was determined by Inductively Coupled Plasma emission spectrometer (ICP), and the satisfied result was obtained. The properties of obtained biodiesel from mixed oil are close to commercial diesel fuel and is rated as a realistic fuel as an alternative to diesel. Production of biodiesel has positive impact on the utilization of agricultural and forestry products.     

Synthesis of fatty acid methyl esters via the transesterification of waste cooking oil by methanol with a barium-modified montmorillonite K10 catalyst

The transesterification of waste cooking oil (WCO) with methanol to produce fatty acid methyl esters (FAMEs) in the presence of barium-modified montmorillonite K10 (BMK10) catalyst was investigated in a batch reactor. The influence of the reaction parameters on the yield of FAME was investigated. The highest value of 83.38% was obtained with 3.5 wt% catalyst loading at 150 °C with a methanol: oil molar ratio of 12:1 during a reaction time of 5 h. BMK10 is a promising low-cost catalyst for the transesterification of WCO to produce FAME.     

Synthesis of fatty acid methyl esters via the methanolysis of palm oil over Ca3.5xZr0.5yAlxO3 mixed oxide catalyst

Novel mixed metal oxide catalyst Ca_3.5xZr_0.5yAl_xO₃ was synthesized through the coprecipitation of metal hydroxides. The textural, morphological, and surface properties of the synthesized catalysts were characterized via Brunauer–Emmett–Teller method, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy. The catalytic performance of the as-synthesized catalyst series was evaluated during the transesterification of cooking palm oil with methanol to produce fatty acid methyl esters (FAME). The influence of different parameters, including the calcination temperature (300–700 °C), methanol to oil molar ratio (6:1–25:1), catalyst amount (0.5–6.5 wt%), reaction time (0.5–12 h) and temperature (70–180 °C), on the process was thoroughly investigated. The metal oxide composite catalyst with a Ca:Zr ratio of 7:1 showed good catalytic activity toward methyl esters. Over 87% of FAME content was obtained when the methanol to oil molar ratio was 12:1, reaction temperature 150 °C, reaction time 5 h and 2.5 wt% of catalyst loading. The catalyst could also be reused for over four cycles.     

Optimization of transesterification conditions for the production of fatty acid methyl ester (FAME) from Chinese tallow kernel oil with surfactant-coated lipase

Surfactant-coated lipase was used as a catalyst in preparing fatty acid methyl ester (FAME) from Chinese tallow kernel oil from Sapium sebiferum (L.) Roxb. syn. Triadica sebifera (L.) small. FAME transesterification was analyzed using response surface methodology to find out the effect of the process variables on the esterification rate and to establish prediction models. Reaction temperature and time were found to be the main factors affecting the esterification rate with the presence of surfactant-coated lipase. Developed prediction models satisfactorily described the esterification rate as a function of reaction temperature, time, dosage of surfactant-coated lipase, ratio of methanol to oil, and water content. The FAME mainly contained fatty acid esters of C16:0, C18:0, C18:1, C18:2, and C18:3, determined by a gas chromatograph. The optimal esterification rate was 93.86%. The optimal conditions for the above esterification ratio were found to be a reaction time of 9.2 h, a reaction temperature of 49 °C, dosage of surfactant-coated lipase of 18.5%, a ratio of methanol to oil of 3:1, and water content of 15.6%. Thus, by using the central composite design, it is possible to determine accurate values of the transesterification parameters where maximum production of FAME occurs using the surfactant-coated lipase as a transesterification catalyst.     

Optimization of biodiesel production from waste cooking oil using waste bone as a catalyst

This work determined the association between several parameters of biodiesel production from waste cooking oil (WCO) using waste bovine bone (WBB) as catalyst to achieve a high conversion to fatty acid methyl ester (%FAME). The effect of three independent variables was used as the optimum condition using response surface methodology (RSM) for maximizing the %FAME. The RSM analysis showed that the ratio of MeOH to oil (mol/mol), catalyst amount (%wt), and time of reaction have the maximum effects on the transform to FAME. Moreover, the coefficient of determination (R²) for regression equations was 99.19%. Probability value (P < 0.05) demonstrated a very good significance for the regression model. The optimal values of variables were MeOH/WCO ratio of 15.49:1 mol/mol, weight of catalyst as 6.42 wt%, and reaction time of 128.67 min. Under the optimum conditions, %FAME reached 97.59%. RSM was confirmed to sufficiently describe the range of the transesterification parameters studied and provide a statistically accurate estimate of the best transform to FAME using WBB as the catalyst.     

Hydroprocessing of Jatropha oil over NiMoCe/Al2O3 catalyst

The non-sulfided NiMoCe/Al₂O₃ catalyst was developed to produce green diesel from the hydroprocessing of Jatropha oil. The NiMoCe/Al₂O₃ catalysts were prepared by impregnation and characterized by N₂-BET, SEM, XRD and TPD-H_ads techniques. The straight chain alkanes ranging from C15 to C18 were the main components in product oil. The maximum yield of C15-C18 alkanes of 80%, selectivity of 90% and conversion of 89% were obtained at 370 °C, 3.5 MPa and 0.9 h⁻¹. Influence of reaction temperature (280–400 °C) and reaction time (10–163 h) on the composition of product oil were discussed. The experimental results demonstrated that a suitable amount of metal Ce doping on the NiMo/Al₂O₃ catalyst presented stable catalytic performance and enhanced Jatropha oil conversion as well as C15-C18 fraction selectivity.     

Effects of water on the esterification of free fatty acids by acid catalysts

To maximize the production of biodiesel from soybean soapstock, the effects of water on the esterification of high-FFA (free fatty acid) oils were investigated. Oleic acid and high acid acid oil (HAAO) were esterified by reaction with methanol in the presence of Amberlyst-15 as a heterogeneous catalyst or sulfuric acid as a homogeneous catalyst. The yield of fatty acid methyl ester (FAME) was studied at oil to methanol molar ratios of 1:3 and 1:6 and reaction temperatures of 60 and 80 °C. The rate of esterification of oleic acid significantly decreased as the initial water content increased to 20% of the oil. The activity of Amberlyst-15 decreased more rapidly than that of sulfuric acid, due to the direct poisoning of acid sites by water. Esterification using sulfuric acid was not affected by water until there was a 5% water addition at a 1:6 molar ratio of oil to methanol. FAME content of HAAO prepared from soapstock rapidly increased for the first 30 min of esterification. Following the 30-min mark, the rate of FAME production decreased significantly due to the accumulation of water. When methanol and Amberlyst-15 were removed from the HAAO after 30 min of esterification and fresh methanol and a catalyst were added, the time required to reach 85% FAME content was reduced from 6 h to 1.8 h.     

Hydrocracking of Jatropha oil over Ni-H3PW12O40/nano-hydroxyapatite catalyst

The Ni-H₃PW₁₂O₄₀/nano-hydroxyapatite catalyst with H₃PW₁₂O₄₀ (HPW) loading was prepared by impregnation method and performed through hydrocracking of Jatropha oil in a fixed-bed reactor. The catalyst was characterized by N₂ adsorption–desorption, powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption of ammonia (NH₃-TPD), thermogravimetric analysis (TGA). The conversion of Jatropha oil over Ni-HPW (30 wt%)/nHA was 100%, the liquid yield of liquid product was 83.4%, the ratio of i/n-paraffins was 1.64 at 360 °C, 3 MPa, H₂/oil (v/v) = 600 and LHSV = 2 h⁻¹. The pour point of final product oil was −28 °C and the catalyst was used without sulfurization.     

Parametric study and optimization of in situ transesterification of Jatropha curcas L assisted by benzyltrimethylammonium hydroxide as a phase transfer catalyst via response surface methodology

In the present work, non-edible oil source, Jatropha curcas oil was used with base catalyzed methanol and ethanol to produce biodiesel using in situ transesterification assisted by Benzyltrimethylammonium hydroxide (BTMAOH) as a phase transfer catalyst (PTC). Experimental investigation showed that base catalyzed in situ transesterification reaction rate was enhanced with the use of BTMAOH as a PTC. During the experiment fast formation of biodiesel was observed in relatively shorter time for PTC assisted reaction as compared to the reaction in the absence of PTC. The effect of individual reaction parameters was investigated using response surface methodology (RSM). Optimum operating conditions were also found statistically. Weight fractions of 89 ± 0.7% fatty acid methyl esters (FAME) yield and 99.4 ± 0.4% fatty acid ethyl esters (FAEE) yield were produced at optimum reaction condition. The fuel quality of FAME and FAEE was investigated against the fuel quality specification set by ASTM D6751 and EN-14214 standards.     

Dimethyl carbonate mediated production of biodiesel at different reaction temperatures

Methanol was replaced by dimethyl carbonate for biodiesel production. In the process, fatty acid methyl ester (FAME) was produced through transesterification of soybean oil with dimethyl carbonate (DMC) using potassium methoxide as a catalyst. This method produced a more attractive by-product, glycerol carbonate (GC). Factors affecting the reaction such as vegetable oil to DMC molar ratio, catalyst concentration, reaction time and reaction temperature were optimized. Triglyceride conversion of 95.8% was obtained at the optimized condition. This process provided an insight into the reactivity of DMC at different temperature. Co-production of FAME and glycerol carbonate (GC) proceeded through carboxymethylation reaction because methoxyl group and carbonyl group are generated which subsequently attacked the carbonyl moiety in glyceride molecules to form the required products.     

Study on the use of MgAl hydrotalcites as solid heterogeneous catalysts for biodiesel production

This paper, reports experimental work on the use of new heterogeneous solid basic catalysts for biodiesel production: double oxides of Mg and Al, produced by calcination, at high temperature, of MgAl lamellar structures, the hydrotalcites (HT). The most suitable catalyst system studied are hydrotalcite Mg:Al 2:1 calcinated at 507 °C and 700 °C, leading to higher values of FAME also in the second reaction stage. One of the prepared catalysts resulted in 97.1% Fatty acids methyl esters (FAME) in the 1st reaction step, 92.2% FAME in the 2nd reaction step and 34% FAME in the 3rd reaction step. The biodiesel obtained in the transesterification reaction showed composition and quality parameters within the limits specified by the European Standard EN 14214. 2.5% wt catalyst/oil and a molar ratio methanol:oil of 9:1 or 12:1 at 60–65 °C and 4 h of reaction time are the best operating conditions achieved in this study. This study showed the potential of Mg/Al hydrotalcites as heterogeneous catalysts for biodiesel production.     

Biodiesel production using gel‐type cation exchange resin at different ionic forms

In this study, a strong acidic‐type cation exchange resin was used in the transesterification of corn oil to fatty acid methyl esters (FAME). The gel‐type cation exchange resin (Purolite‐PD206) was used in H⁺ and Na⁺ forms to utilize ion‐exchange resin as effective heterogeneous catalyst in the production of biodiesel. Effect of ionic forms of ion exchange resin on free fatty acid (FFA) conversion and composition was investigated by using different amounts of ion exchange resin (12, 16, and 20 wt%), various mole ratios of methanol to oil (1:6, 1:12, and 1:18 mol/mol), reaction temperatures (63, 65, and 67°C), and reaction time (24, 36, and 48 h) during transesterification reaction. The highest FFA conversions of 73.5% and 79.45% were obtained at conditions of 20 wt% of catalyst, 65°C of reaction temperature, 18:1 as methanol to oil ratio, and 48 h of reaction time for H⁺ and Na⁺ forms of ion exchange resin, respectively. These results were obtained from regression equations established by using analysis of variance (ANOVA) model according to the experimental results of selected parameters. Gas chromatography analysis revealed that FAME is mainly composed of C16:0 (palmitic), C18:1 (oleic), and C18:2 (linoleic) acids of methyl ester.