Methanolysis Of Palm Oil Research Articles

Optimization of 1,3-propanediol production from fermentation of crude glycerol by immobilized Bacillus pumilus

This study investigates the application of crude glycerol to the production of 1,3-propanediol by immobilized cells of Bacillus pumilus. This is a novel application of a naturally occurring producer obtained from a wastewater storage pond in Thailand. Crude glycerol was obtained through the methanolysis of palm oil, which was catalyzed using rice bran lipase. Ten components of the fermentation medium were screened using a Plackett-Burman design. The statistical significance of the results was determined using multiple linear regression with a backward elimination approach. The significance level was set to 5 % (p < 0.05). Only crude glycerol, (NH4)2SO4, MgSO4, and CaCl2 significantly affected 1,3-propanediol production by immobilized B. pumilus. Furthermore, preliminary screenings of environmental conditions used for 1,3-propanediol production were conducted using a Plackett-Burman design. The results showed that the temperature, time, and quantity of immobilized cells were factors that significantly affected 1,3-propanediol yield. Therefore, the quantities of crude glycerol, (NH4)2SO4, MgSO4, and CaCl2 and the temperature, time, and quantity of immobilized cells were optimized using response surface methodology based on a Box-Behnken design. The model predicted a maximum 1,3-propanediol yield of 45.68 g/L with the following conditions: 60 g/L crude glycerol, 5 g/L (NH4)2SO4, 0.55 g/L MgSO4, 0.05 g/L CaCl2, a fermentation duration of 101 h, and a temperature of 25 °C, with 250 g of immobilized cells. The validation trials confirmed a production level of 44.12 ± 1.81 g/L, indicating a 2.86-fold production increase relative to the control group. Overall, this study demonstrates the potential of using crude glycerol as a substrate to improve the yields of 1,3-propanediol produced by B. pumilus.

Synthesis of magnetic basic palm kernel shell catalyst for biodiesel production and characterisation and optimisation by Taguchi method

This paper illustrated the latest breakthroughs which involved the use of eco-friendly and recyclable magnetic palm kernel shell-derived catalysts (Fe-PKS and Fe-KOH-PKS) for methanolysis of palm oil to produce biodiesel. The magnetic catalyst is obtained from abundant carbon-based biomass, i.e. waste palm kernel shell using pyrolysis. Characterisation of the catalyst with field-emission Scanning Electron microscopy (FESEM), energy-dispersive X-Ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET), vibrating sample magnetometer (VSM), temperature-programmed desorption of CO2 (TPD-CO2) thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FTIR) analysis was conducted to correlate the catalyst characteristic with transesterification activity. The presence of KOH in the catalyst has beneficial effects on the catalyst performance in transesterification. Next, the L-9 orthogonal set-up of experimental factors established by the Taguchi method was employed to determine the optimal operating conditions for Fe-KOH-PKS catalyst. The highest biodiesel yield of 99.43% using Fe-KOH-PKS catalyst was achieved with optimal operating conditions of 7.5 wt% catalyst loading, 9:1 methanol to oil ratio at 65 °C after 2 h. The catalyst was reused for four cycles, with the final run of biodiesel yield of 70.1%. This reflects the synthesised magnetic waste catalyst from palm kernel shell has demonstrated satisfied reusability and good stability in producing biodiesel.

The effects of durian skin ash concentration in methanolysis reaction of palm oil on fatty acid methyl esters concentration

Biodiesel is an alternative fuel made by methanolysis reaction of palm oil. Methanolysis reactions require a catalyst to accelerate the biodiesel formation reaction. The catalyst used in this study was the durian skin ash. This study was conducted to determine the effect of durian skin ash concentration on fatty acid methyl ester content that result in the reaction of palm oil methanolysis. Durian skin ash concentrations were varied to 1%, 2%, 3%, 4% and 5%. The methanolysis reaction was carried out by mixing palm oil, methanol and the ash of calcined durian skin at a temperature of 800°C for 5 hours. The reaction mixture was heated at a temperature of 50 to 70°C for 2 hours. The results of this study showed that the fatty acid methyl esters content increased with the concentration of durian skin ash up to 4% i.e. 90.03%. Fatty acid methyl esters content decreased on the durian skin ash concentration of 5% i.e. 85.66%. These results indicate that the fatty acid methyl esters reached the optimum content in 4% concentration of durian skin ash.

Copper ferrite spinel oxide catalysts for palm oil methanolysis

Copper ferrite spinel oxide (CuFe2O4) samples with calcination temperatures ranging from 500 to 900°C were synthesized using the sol-gel combustion method with citric-nitrate precursors. Each calcined sample was further characterized and carefully analyzed for its structure, morphology, porosity, magnetic property and reducibility. For the first time, the catalytic performance of the ferrite spinels was examined for palm oil methanolysis. The characterization results from X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) analyses revealed that the major part of the active species was divalent ions of Cu2+ and Fe2+ and that they played a crucial role in the activity of the considered spinel catalysts. The catalytic behaviors strongly depended on the crystallinity of spinel structures and operating parameters, such as the catalyst loading and methanol to oil molar ratio. The CuFe2O4 calcined at 700°C was the most active and selective for methanolysis with palm oil. No activity decline was observed over the catalyst after it was reused for 5 cycles without any post-treatment. Easy and effective catalyst separation could be obtained when magnetization was applied to the magnetic spinel catalysts.

Comparative study of natural dolomitic rock and waste mixed seashells as heterogeneous catalysts for the methanolysis of palm oil to biodiesel

Natural dolomitic rock and waste mixed seashells were investigated as renewable sources for preparing heterogeneous catalysts for the methanolysis of palm oil to biodiesel as fatty acid methyl esters (FAME) at 60 °C and ambient pressure. After calcination at 800 °C, the dolomite as the mixed CaO·MgO catalyst possessed smaller CaO crystallites, a higher thermal stability and higher basicity than the pure CaO catalyst derived from the seashells. Although both catalysts gave the FAME yield >98% (w/w), the calcined dolomite exhibited a faster methanolysis rate and higher stability in use than the likewise calcined seashells. The linear correlation of the FAME yield to the amount of CaO phase containing in both catalysts supported that CaO was the active site. The catalyst deactivation was relevant to the formation of calcium glyceroxides. The presence of MgO dispersed in the CaO matrix was important for the superior physicochemical and catalytic properties of the natural dolomite calcined at 800 °C.

Gel-combusted Ca-based catalysts for methanolysis of palm oil

Gel-combustion technique was applied to synthesize CaO catalysts for effective biodiesel production via palm oil methanolysis. The developed catalyst was a group of submicron-sized bonded CaO particles with meso-to-macro interparticle porous structure. Thus, this structure provided much smaller particle size, higher specific surface area and porosity, compared to the CaO from direct calcination of Ca nitrate or carbonate. Among the catalysts studied, the gel-combusted CaO exhibited the highest amounts of basic site, providing the highest catalytic activity in the methanolysis. The FAME content of >96.5% (Thailand national standard) was obtained over gel-combusted CaO within 90min and at mild reaction temperature of 60°C.

Kinetics of Jatropha oil methanolysis

The effect of temperature, methanol to oil molar ratio and catalyst concentration on Jatropha oil methanolysis were studied in the range from 40 to 60°C, 3 to 12 and 0.2 to 1wt% (NaOH), respectively. 100% Conversion of Jatropha oil and 97% yield to fatty acid methyl esters (FAME) were obtained after 60min of reaction at 60°C, methanol to oil molar ratio 6:1 and 0.6wt% of NaOH. Catalyst concentration increment between 0.2wt% and 0.6wt% had a positive effect on the reaction rate and on the yield to FAME. Furthermore, catalyst concentrations of 0.2wt% did not show catalytic activity at all the temperatures tested. A second order kinetic model that includes the three consecutive reversible reactions involved in triacylglycerol methanolysis and the effect of temperature and catalyst concentration on reaction rate describes adequately Jatropha oil methanolysis, as validated by the Fisher–Snedecor test of unbiased variances. A set of eighteen parameters: six kinetic constants, six activation energies and six parameters related to the catalyst concentration were determined using a Dual Population Evolutionary Algorithm (DPEA). Finally, the kinetic model parameters of Jatropha oil and palm oil methanolysis were compared. Parameters obtained were similar in both reactions.

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

Novel mixed metal oxide catalyst Ca3.5xZr0.5yAlxO3 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.

Biodiesel production in a counter-current reactive extraction column: Modelling, parametric identification and optimisation

Reactive extraction is a potential alternative for biodiesel production, in which reaction and glycerol separation are simultaneous, increasing conversion, yield and process productivity. This paper presents a stepwise reaction–separation model for a counter-current reactive extraction column, used in homogeneous-base-catalyzed palm oil methanolysis, and the models’ parameters are identified from the results of a set of experimental tests. In addition, multi-criteria optimisation of the process conditions was performed using an evolutionary algorithm. The optimum conditions provide for palm oil conversion of 97.7%, a yield to FAME of 99.5% and a process productivity of 1.4m3 FAMEh−1m−3 in a single reaction step. Finally, a comparison of the process productivity with co-current and batch processes was made. As the counter-current reactive extraction process does not require the intermediate separation stages required in co-current and batch processes, its productivity is 1.5 and 6.9 times higher than those processes, respectively.

A robust whole-cell biocatalyst that introduces a thermo- and solvent-tolerant lipase into Aspergillus oryzae cells: Characterization and application to enzymatic biodiesel production

To develop a robust whole-cell biocatalyst that works well at moderately high temperature (40–50°C) with organic solvents, a thermostable lipase from Geobacillus thermocatenulatus (BTL2) was introduced into an Aspergillus oryzae whole-cell biocatalyst. The lipase-hydrolytic activity of the immobilized A. oryzae (r-BTL) was highest at 50°C and was maintained even after an incubation of 24-h at 60°C. In addition, r-BTL was highly tolerant to 30% (v/v) organic solvents (dimethyl carbonate, ethanol, methanol, 2-propanol or acetone). The attractive characteristics of r-BTL also worked efficiently on palm oil methanolysis, resulting in a nearly 100% conversion at elevated temperature from 40 to 50°C. Moreover, r-BTL catalyzed methanolysis at a high methanol concentration without a significant loss of lipase activity. In particular, when 2 molar equivalents of methanol were added 2 times, a methyl ester content of more than 90% was achieved; the yield was higher than those of conventional whole-cell biocatalyst and commercial Candida antarctica lipase (Novozym 435). On the basis of the results regarding the excellent lipase characteristics and efficient biodiesel production, the developed whole-cell biocatalyst would be a promising biocatalyst in a broad range of applications including biodiesel production.

Potential use of whole cell lipase from a newly isolated Aspergillus nomius for methanolysis of palm oil to biodiesel

► Highly active whole cell lipase (WCL) from a newly isolated Aspergillus nomius . ► Isolated A. nomius grow better on waste cooking oil than glucose. ► Potential use of A. nomius WCL for methanolysis of palm oil to biodiesel. ► Isolated A. nomius WCL is more active than most WCLs previously reported. ► Stabilization of WCL by immobilizing onto polyurethane foam. A highly active whole cell lipase (WCL) for efficient methanolysis of palm oil (PO) to biodiesel (BD) was prepared by isolation, cultivation and immobilization of lipase producing fungi. Fungi were screened from soil and the best isolate (PDA-6) identified as Aspergillus nomius exhibited maximum WCL methanolysis activity (1.4 g h −1 g −1 ) when inexpensive waste cooking oil was used as carbon source. The maximum BD yield with PDA-6 WCL reached 95.3% after 40 h at a lipase load 10% (w/w) of PO and methanol to PO molar ratio 5:1. The immobilization of PDA-6 cells within biomass suspended particle (BSP) made of polyurethane foam improved the repeated use of WCL and the remaining activity after 10 cycles was 88.2%. The PDA-6 WCL was more active in methanolysis of PO to BD than most WCLs previously reported. The newly isolated A. nomius is not only potential for producing WCL but also utilizing waste cooking oil.

A newly isolated fungal strain used as whole‐cell biocatalyst for biodiesel production from palm oil

AbstractA strain of Aspergillus niger isolated from atmospherically exposed bread and Jatropha curcas seed was utilized as a whole‐cell biocatalyst for palm oil methanolysis to produce fatty acid methyl esters (FAME), or biodiesel. The A. niger strain had a lipase activity of 212.58 mU mL−1 after 144 h incubation at 25 °C with an initial pH value of 6.5, using 7% polypeptone (w/w on basal medium) as the nitrogen source and 3% olive oil (w/w on basal medium) as a carbon source. The A. niger cells spontaneously immobilized within polyurethane biomass support particles (BSPs) during submerged fermentation. Thereafter, the methanolysis of palm oil was achieved via a three‐step addition of methanol in the presence of BSPs‐immobilized with A. niger cells. The influence of water content, reaction temperature and enzyme concentration on reaction rate was investigated. An 8% water content and a temperature of 40 °C in the presence of 30 immobilized BSPs, resulted in an 87% FAME yield after 72 h.

Continuous Methanolysis of Palm Oil Using a Liquid–Liquid Film Reactor

AbstractA system for the continuous methanolysis of palm oil using a liquid–liquid film reactor (LLFR) was developed and characterized. This reactor is a co‐current, constant diameter (0.01 m), custom‐made packed column where the mass transfer area between the partially miscible methanol‐rich and vegetable oil‐rich phases is created in a non‐dispersive way, without the intervention of mechanical stirrers or ultrasound devices. An increase in contact area between phases enhances reaction rate while the absence of small, dispersed droplets of one phase into the other diminishes the settling time at the end of the reaction. In this study variations on the concentration of catalyst (sodium hydroxide), flow rate of palm oil and normalized length of the reactor (L/Lmax) were explored, keeping constant both the methanol to oil molar ratio and the temperature of the reaction (6:1 and 60 °C). The best experimental results with a reactor of 1.26 m (L/Lmax = 1.0) showed a conversion of palm oil of 97.5% and a yield of methyl esters of 92.2% of the theoretical yield, when the mass flow rate and the residence time of the palm oil were 9.0 g min−1 and 5.0 min, respectively. To determine the mean residence time and the degree of axial mixing in the reactor, a residence time distribution (RTD) study was performed using a step‐function input. The dispersion model appears to fit well the RTD experimental data.

Improved Method for Efficient Production of Biodiesel from Palm Oil

Biodiesel (methyl esters of long-chain fatty acids) can be produced by methanolysis of vegetable oils using lipase as a biocatalyst. However, the lipase, such as immobilized Candida antarctica lipase B (Novozym 435), is poisoned as a result of the contact with insoluble methanol, reducing the lipase activity. To minimize the problem, a salt-solution-based controlled release system for methanol is developed. The developed method can easily minimize the problem by dissolving methanol in the salt solution and keeping an acceptable methanol concentration in vegetable oil, thereby increasing the lipase activity. The results of methanolysis of palm oil in the salt-solution-based methanol release system are compared to those in a salt-solution-free system, where methanol is added by the traditional method of three successive additions of methanol. The maximum biodiesel yields in both systems are the same (97%), but methanolysis in the developed method progresses 4-fold faster than that in the traditional method. It is found that a LiCl-saturated solution stabilizes Novozym 435 against heat-induced inactivation. The results suggest that the salt-solution-based methanol release system can be an acceptable substitution for the traditional method and provides an efficient method for biodiesel production.

Kinetics of Palm Oil Methanolysis

AbstractA kinetics study of palm oil methanolysis was conducted at three different temperatures and three different concentrations of catalyst, sodium hydroxide, keeping constant the molar ratio of methanol to oil and the rotational speed of the impeller (6:1 and 400 rpm). The maximum conversion of palm oil and productivity to methyl esters were obtained at 60 °C and 1 wt% of NaOH based on palm oil, and they were 100 and 97.6%, respectively. The statistical analysis of conversions of palm oil and productivities to methyl esters as functions of temperature and concentration of catalyst, after 80 min of reaction, allowed them to fit second order polynomial equations, which adequately describe the experimental behavior. The experimental data appear to be a good fit into a second order kinetic model for the three stepwise reactions, and the reaction rate constants and the activation energies were determined. In this article we present the kinetic constant and activation energies for the experiments with 0.2% wt of NaOH. The effect of molar ratio on the concentration of products was investigated, while the temperature (55 °C), the concentration of catalyst (0.60 wt% of NaOH), and the rotational speed (400 rpm), were held constant. The results showed that the conversion and the productivity increased due to methanol excess, and were higher for the reactions with a molar ratio of 6:1.

Proposed kinetic mechanism of the production of biodiesel from palm oil using lipase

Experimental determination of the separate effects of palm oil and methanol concentrations on the rate of their enzymatic transesterification was used to propose suitable mechanismic steps and to test the generated kinetic model. The reaction took place in n-hexane organic medium and the lipase used was from Mucor miehei. At a constant methanol concentration of 300 mol m −3, it was found that, initially as the palm oil concentration increased, the initial reaction rate increased. However, the initial rate dropped sharply at substrate concentrations larger than 1250 mol m −3. Similar behaviour was observed for methanol concentration effect, where at a constant substrate concentration of 1000 mol m −3, the initial rate of reaction dropped at methanol concentrations larger than 3000 mol m −3. Ping Pong Bi Bi mechanism with inhibition by both reactants was adopted as it best explains the experimental findings. A mathematical model was developed from a proposed kinetic mechanism and was used to identify the regions where the effect of inhibition by both substrates arised. The proposed model equation is essential for predicting the rate of methanolysis of palm oil in a batch or a continuous reactor and for determining the optimal conditions for biodiesel production.

Lipase-catalyzed methanolysis of palm oil in presence and absence of organic solvent for production of biodiesel

Enzymatic production of methyl esters (biodiesel) by methanolysis of palm oil in presence and absence of organic solvent was investigated using Candida antarctica lipase immobilized on acrylic resin as a biocatalyst. Although, at least molar equivalent of methanol (methanol–palm oil ratio 3:1) is required for the complete conversion of palm oil to methyl esters, lipase catalyzed methanolysis of palm oil in absence of organic solvent was poisoned by adding more than 1/3 molar equivalent of methanol. The use of polar organic solvents prevented the lipase to be poisoned in methanolysis with a molar equivalent of methanol, and tetrahydrofuran (THF) was found to be the most effective. The presence of water in methanolysis of palm oil both in presence and absence of THF inhibited the reaction rate but this inhibition was considerably low in THF containing system. The palm oil-lipase (w/w) ratio significantly influenced the activity of lipase and the optimal ratio in presence and absence of THF was 100 and 50, respectively.

Palm oil trans-esterification with methanol via heterogeneous catalysis

Four different solid catalysts’ catalytic activity was studied in refined palm oil methanolysis: barium hydroxide, calcium oxide, magnesium oxide and tin oxide (IV). The last two presented low catalytic activity; they were thus discarded. The catalysts were used in powder form suspended in the reaction medium. HPLC was used for testing catalytic activity by measuring the glycerol produced at the end of the reaction. Experiments were conducted at different pressures: 75 kPa (the pressure in Bogotá), 760 kPa, 1.800 kPa, 5.900 kPa and 11.400 kPa, 125°C (760 kPa) and 160°C (1,800 kPa). Three different percentages of catalyzer were assayed at 75 kPa and two experiments were done at very high pressure (10.9 psi) around methanol’s critical point (6.900 and 11.400 kPa). Both barium hydroxide and calcium oxide presented high catalytic activity. 75%-80% conversion was obtained with them in 8-10 hours at 63.3°C and 1.5 and 3 hours using calcium oxide and barium hydroxide (respectively) at high temperatures and pressures.

Gas chromatography determination of fatty acid alkyl esters (methyl and ethyl) in the presence of mono-, di- and triglycerides

Determining fatty acid methyl or ethyl esters, in the presence of mono-, di- and tri glycerides, is very important when studying fatty compounds’ methanolysis or ethanolysis, as well as for controlling the quality of petrochemical products. This work presents a useful technique for determining fatty acids methyl or ethyl esters by high temperature gas chromatography in the presence of mono-, di- and triglycerides. Samples were silylated with N, O-bis (trimethylsilyl) tritluoroacetamide (BSTFA) and then passed through a 12 m HT5 column coated with a phenylpolysiloxane-carborane film. Standard methyl and ethyl palmitate, methyl and ethyl oleate, DL-α palmitin, dipalmitin, tripalmitin and triolein solutions were used for calibrating the technique, using tricaprin as internal standard. Retention times and response factors were also determined. The results were employed in following-up palm oil methanolysis and ethanolysis reactions.