Transesterification Of Cottonseed Oil Research Articles

Utilization of waste from paper industry as a heterogeneous base catalyst for the synthesis of biodiesel

AbstractTo meet the pressing demand for alternative biofuel in the contemporary world, the production cost of biodiesel has to be decreased. Hence, this work addresses the usage of CaCO3‐rich industrial waste produced in a local paper industry in Assam, India for the synthesis of a heterogeneous catalyst for biodiesel synthesis. The collected lime sludge waste was subjected to calcination at 800°C for 3 h producing a CaO‐rich catalyst which was then employed in the transesterification of cottonseed oil. The optimized reaction conditions obtained were 5 wt% catalyst concentration, oil to methanol molar ratio of 1:12 at 65°C temperature, and 3 h of reaction time. The catalyst's reusability was evaluated up to four cycles. Besides, the prepared catalyst has been characterized using Fourier transfer infrared spectroscopy (FTIR), powder X‐ray Diffraction (p‐XRD), Scanning Electron Microscope (SEM), Energy Dispersive X‐ray analysis (EDX), and Brunauer–Emmett–Teller (BET) techniques and its basicity was measured using Hammett indicators. Moreover, the biodiesel obtained was characterized with 1H‐nuclear magnetic resonance (NMR), 13C‐NMR, Gas Chromatography‐ Mass Spectrometry (GC–MS), and FTIR techniques. A biodiesel yield of 98.03% was achieved and the quality of biodiesel formed during the transesterification of CSO also conforms to EN 14214 and ASTM D 6751 standards. Thus, our study highlights the sustainability and the potential for future industrial application of paper industrial waste in the production of biodiesel.

Monitoring of the transesterification reaction by continuous off-line density measurements

The main route for industrial production of biodiesel is through the transesterification reaction of different source of triglycerides. Continuous monitoring of the process is very important in order to optimize operational parameters, foresee troubles and guarantee the quality of final product. In this work, the transesterification of cottonseed oil at 50 °C and 70 °C, with methanol/oil molar ratios of 4.5, 6.0 and 7.5 was carried out, and the oil conversion as a function of reaction time was evaluated by 1H NMR. The density of the reaction mixture, at these experimental conditions, was measured as a function of the reaction time by an off-line methodology. From the density-time and oil conversion-time profiles an operative relationship between conversion, density, alcohol to oil ratio and temperature was established.

Influence of acyl acceptor blends on the ester yield and fuel properties of biodiesel generated by whole-cell catalysis of cottonseed oil

One of the promising alternatives to fossil fuels, biodiesel, is a renewable fuel which can be defined as methyl or ethyl ester of fatty acid made prominently from vegetable oils or animal fat. The present study outlines the observations on the fatty acid alkyl ester generation by transesterification of cottonseed oil using Aspergillus species as whole-cell biocatalyst. Current work also represents the difference in ester yield on the addition of alcohol blends with two different molar ratios (1:4 or 1:6). Further, the fuel properties viz., density, viscosity, gross calorific value, flash point, cloud point and pour point of ethyl-butyl and ethyl-propyl ester were analyzed, as per ASTM 6751. No significant difference was observed in ester yield with both the molar ratio of alcohols. Ester yield up to 91% and 87% was obtained using 1:4 and 1:6 M ratio respectively. By the use of a lower molar ratio (1:4) and whole-cell catalyst, a significant reduction in the cost of production of biodiesel is as expected. Alcohol other than ethanol facilitated only a marginal increase in ester yield with no significant variation from propanol to octanol. The fuel properties showed significant improvement in comparison to standard biodiesel. The use of whole cell bio-catalysis, as demonstrated in present study can be considered as a promising alternative to a chemical catalyst for the generation of long-chain fatty acid esters.

Production of Biodiesel from Cottonseed Oil over Aminated Flax Fibres Catalyst: Kinetic and Thermodynamic Behaviour and Biodiesel Properties

The transesterification of cottonseed oil in the presence of methanol to fatty acid methyl ester (FAME) using flax-based fibres catalyst modified with an alkaline moiety was studied. The catalyst was prepared by radiation induced grafting (RIG) of glycidyl methacrylate (GMA) onto dignified flax fibres followed by amination with diethylamine (DEA) and treatment with NaOH solution. A maximum FAME conversion of 88.6% was obtained at 60°;C with a catalyst dosage of 2.5 wt%, an oil/methanol ratio of 1:33 and a time of 2 h. The biodiesel quality was verified by nuclear magnetic resonance (1H NMR). Kinetic analysis showed a reaction activation energy of 69.33 kJ·molˉ1 and a rate constant of 0.00349 minˉ1 indicating that the catalytic reaction was kinetically controlled. Thermodynamic analyses revealed that the reaction was reversible, non-spontaneous and endothermic with an enthalpy of 66.62 kJ·molˉ1. The obtained biodiesel showed physical and chemical characteristics complying with ASTM D6751. It can be concluded that the alkaline biopolymer catalyst prepared in the present study is a promising green candidate for biodiesel production.

Effect of reaction parameters on the catalytic transesterification of cottonseed oil using silica sulfuric acid

ABSTRACTTransesterification of refined cottonseed oil was studied in the presence of silica sulfuric acid as a new heterogeneous solid acid catalyst to overcome the drawbacks of homogeneous alkali and acid catalysts. The effect of various reaction parameters, such as oil to methanol ratio, reaction temperature, reaction time, and catalyst amount, was investigated. The highest methyl ester conversion was obtained at 373 K using 5% catalyst amount and 1:20 methanol ratio within 8 h. Silica sulfuric acid was found to be a promising catalyst for cleaner biodiesel production without tedious post treatments for the product purification.

Biodiesel synthesis from cottonseed oil using homogeneous alkali catalyst and using heterogeneous multi walled carbon nanotubes: Characterization and blending studies

The trans-esterification of cottonseed oil using strong alkali catalyst and using multi walled carbon nano tubes as catalyst to produce biodiesel was studied. The interaction effects of various factors such as temperature, amount of alkali used, alcohol to oil ratio and reaction time on yield of biodiesel were studied. The maximum yield of 95% biodiesel was obtained. The biodiesel produced was characterized using FT-IR spectral analysis and GC–MS analysis to ascertain the various functional groups and compounds available in it. The properties of biodiesel using homogeneous alkali catalyst and heterogeneous multi walled carbon nanotubes such as calorific value (36.18MJ/kg, 33.78MJ/kg), flash point (160°C, 156°C) and other properties such as viscosity, cloud point, pour point and density were found to determine the quality of biodiesel produced. The studies were done by blending the biodiesel produced with diesel and properties of blended samples were estimated to ascertain the use of blended samples in internal combustion engines.

Optimization of Lipase-Catalyzed Transesterification of Cotton Seed Oil for Biodiesel Production Using Response Surface Methodology

The aim of this work was to study the biodiesel production from cotton seed oil by lipase produced by Pichia guilliermondii lipase, which was immobilized onto hydrophobic magnetic particles (HMPs). The optimum reaction conditions were determined for lipase dosage, methanol-to-oil molar ratio, temperature and water content. Using response surface methodology, a quadratic polynomial equation was obtained for fatty acid methyl esters (FAMEs) content by multiple regression analysis. Verification experiments confirmed the validity of the predicted model. The optimal conditions for the enzymatic transesterification were temperature of 38.76℃, 31.3% immobilized lipase, 10.4% water content, and a methanol-to-oil molar ratio of 4.715:1. The gas chromatography- mass spectrometry showed that biodiesel was mainly composed of the methyl esters of hexadecanoic, 9,12-octadecadienoic and 9-octadecadienoic acid.

Biodiesel Production from Cottonseed Oil by Micro-Flow System

Currently, continuous synthesis of biodiesel has been widely studied due to a series of problems imposed by biphasic reaction and thermodynamic, as well as to reduce production costs. In this work, transesterification of cottonseed oil to biodiesel was carried out in a microtube reactor with a micromixer. The effects of molar ratio of ethanol to cottonseed oil, reaction temperature and residence time had been experimentally discussed. The optimal result was obtained under the conditions of oil-to-ethanol molar ratio of 1:16, a residence time of 7min, and a temperature of 70°C.

Purification of Crude Glycerine Obtained from Transesterification of Cottonseed Oil

Abstract The objective of this study was to purify glycerine obtained from the transesterification of cottonseed oil, using ion exchange resins. The batch process used strong cation, weak anion and a mixture of its resins. The purified glycerine was characterized as to metal content, colour and glycerol content. The experiments were conducted using the resins individually and in series. In the experiments in series, there was a constant decrease in conductivity. Analyses without the use of charcoal showed that conductivity behaved similarly to that of treatment with charcoal. For conductivity tests using activated charcoal and individual resins, the mixed resin produced the best result when compared to commercial glycerine.Considering the analysis made with activated carbon, when the glycerine solution was treated with individual resins, it was observed that the conditions established for treatment with 10 g of resin, 5 hours of contact with each resin and 50 mL of glycerine, its conductivity decreased to the cation exchange resin, increased to anionic resin and had a variable value with respect to the mixed resin. In serial processing, there was a steady decrease in the conductivity of the glycerine solution. The content of glycerol, after the solution had been passed through activated charcoal, 56% of the compound was recovered. It was also observed that the mixed resin retained a lower amount of glycerol. It can be concluded that ion exchange resins were efficient in treating the glycerine solution in all the tests, since there was little glycerol retention and high undesirable compound retention.

CaO loaded with Sr(NO3)2 as a heterogeneous catalyst for biodiesel production from cottonseed oil and waste frying oil

The transesterification of cottonseed oil and used frying oil to methyl esters (biodiesel) was studied using Sr(NO3)2 loaded onto calcium oxide as heterogeneous catalyst. Reaction parameters such as catalyst concentration, methanol/oil ratio, and reaction time on the conversion of cottonseed oil and used frying oil were investigated. The 35 % m/m Sr(NO3)2 catalyst loaded onto CaO, after being calcined at 750 °C for 6 h, was found to be the optimum catalyst. The quality of the methyl esters was tested according to the European standard ELOT EN 14214. The two types of biodiesel produced seemed to meet all the parameters of the European standard, except oxidation stability.

Liquid-Liquid Equilibrium of Methyl Esters of Fatty Acid / Methanol / Glycerol and Fatty Acid Ethyl Esters / Ethanol / Glycerol: A Case Study for Biodiesel Application

Biodiesel is a fuel commonly produced through the process of transesterification or alcoholysis. In this reaction, triglycerides react with short chain alcohols, producing a mixture of fatty acid esters (biodiesel) and glycerol. Esters of fatty acids and glycerol are partially miscible, forming two liquid phases in the separation of these products. The determination of equilibrium data for liquid-liquid (ELL) for these systems is essential to a better understanding of the reaction process, improving the reaction rate, selectivity, and simulation and optimization of the reactor and the system of separation of products. In this paper we experimentally measured data for ELL pseudo-ternary systems of fatty acid methyl esters (FAME)/methanol/glycerol and fatty acid ethyl esters (FAEE)/ethanol/glycerol at 30, 45 and 60 ° C. The biodiesel used in this work was produced by transesterification of cottonseed oil. The measured experimental data were used to evaluate the prediction of the UNIFAC method for such systems.

Immobilization of Candida rugosa Lipase on MCM-41 for the Transesterification of Cotton Seed Oil

Present study demonstrated the preparation of MCM-41 as a support for the immobilization of Candida rugosa lipase by the physical adsorption technique. The lipase immobilized MCM-41 has been characterized by scanning electron microscopic and FTIR techniques. At pH 6, maximum lipase immobilization (250 mg/g) on MCM support has been observed and the immobilized lipase was employed as biocatalyst for the transesterification of the cotton seed oil with methanol. The pH of the reaction medium, reaction temperature and methanol/oil molar ratio have been optimized to achieve a maximum 98±3% fatty acid methyl esters yield (FAMEs)from cotton seed oil.

Transesterification of Cotton-Seed Oil by Heterogeneous Solid Super Base KF/MgO Catalyst

An environmentally benign process was developed for the production of biodiesel from cotton-seed oil using KF loaded with MgO as a heterogeneous solid super base catalyst. The 20 wt% KF/MgO, after desiccated at 120 oC for 4 h, was found to be the optimum catalyst. Hammett indicator method, XRD, SEM and IR were employed for the catalyst characterization. The results showed the activity of the catalysts was correlated with their basicity. The influence of various reaction variables on the conversion, such as the molar ratio of methanol to cotton-seed oil, the catalyst amount, the reaction time and temperature were also discussed. When the transesterification reaction was carried out at reflux of methanol (65 oC), with a molar ratio of methanol to cotton-seed oil 12 : 1, a reaction time 2.5 h and a catalyst amount 2.5 wt%, the highest conversion of cotton-seed oil reached 99.14%.

Effect of Composition on the Structure and Catalytic Properties of KF/Mg–La Solid Base Catalysts for Biodiesel Synthesis via Transesterification of Cottonseed Oil

A series of solid bases (KF/Mg–La) with different Mg/La mass ratios and varied KF loadings were prepared, and applied to biodiesel synthesis by transesterification of cottonseed oil. ICP, XRD, CO2–TPD, TPDE, and FTIR were employed to characterize the catalysts in order to reveal the correlation of the composition with the structure and the basicity of the solid bases. The catalyst with Mg/La mass ratio of 3% and 30.9% (wt/wt precursor) KF loading possessed the highest catalytic activity. Under the optimal reaction condition of methanol/oil molar ratio of 12:1, reaction for 1 h at 65 °C, and 5% (wt/wt oil) catalyst amount, the TOF on 30.9% KF/M3L could reach 3.28 × 10–2 mol s–1 mol–1. The Arrhenius activation energy was evaluated to be 54.74 kJ·mol–1.

Biocatalytic production of biodiesel from cottonseed oil: Standardization of process parameters and comparison of fuel characteristics

The enzymatic production of biodiesel by transesterification of cottonseed oil was studied using low cost crude pancreatic lipase as catalyst in a batch system. The effects of the critical process parameters including water percentage, methanol:oil ratio, enzyme concentration, buffer pH and reaction temperature were determined. Maximum conversion of 75–80% was achieved after 4 h at 37 °C, pH 7.0 and with 1:15 M ratio of oil to methanol, 0.5% (wt of oil) enzyme and water concentration of 5% (wt of oil). Various organic solvents were tested among which a partially polar solvent ( t-butanol) was found to be suitable for the reaction. The major fuel characteristics like specific gravity, kinematic viscosity, flash point and calorific value of the 20:80 blends (B20) of the fatty acid methyl esters with petroleum diesel conformed very closely to those of American Society for Testing Materials (ASTM) standards.

Effect of frying time on free fatty acid generation and esterification rate in Aspergillus sp.-catalyzed transesterification of cottonseed oil

The present study was carried out to examine the effect of different frying times of edible oil on the extent of transesterification catalyzed by the whole-cell biocatalyst, Aspergillus (RBD01). Cottonseed oil was chosen as a conventional and cost-effective edible oil used commercially in India. The results showed that increased frying time of the oil decreased the extent of the transesterification reaction and hence alkyl ester production. Nearly complete (>98%) transesterification to ethyl alcohol was observed with used oil containing a free fatty acid (FFA) content of 3.7%, whereas beyond an FFA content of 4.0% the yield was reduced. Biocatalyzed hydrolysis (in the absence of the ethyl alcohol acceptor) of used frying oil resulted in decreasing yield of FFA from 84.0% to 27.6% with increasing frying time. With fried oil capable of a hydrolysis yield of 82–41% FFA, transesterification reactions were nearly complete. With the lower hydrolysis yields of 38–27% FFA, the transesterified ethyl ester yield decreased to 61–51%. These observations indicate that factors other than the presence of FFA and moisture influence the biocatalytic transesterification of used cooking oils.

Biodiesel production using tetramethyl- and benzyltrimethyl ammonium hydroxides as strong base catalysts

In recent years, the acceptance of fatty acid methyl esters (biodiesel) as an alternative fuel has rapidly grown in EU. The most common method for biodiesel production is based on triglyceride transesterification to methyl esters with dissolved sodium hydroxide in methanol as catalyst. In this study, cottonseed oil and used frying oil were subjected to the transesterification reaction with tetramethyl ammonium hydroxide and benzyltrimethyl ammonium hydroxide as strong base catalysts. This work investigates the optimum conditions for biodiesel production using amine-based liquid catalysts. Biodiesel ester content was strongly related with the type of feedstock and the reaction variables, such as those of the catalyst concentration, methanol to oil molar ratio, and reaction time. The overall results suggested that the transesterification of cottonseed oil achieved high conversion rates with both catalysts, while the use of waste oil resulted in lower yields of methyl esters due to the possible formation of amides.

Continuous production of biodiesel from high acid value oils in microstructured reactor by acid-catalyzed reactions

Acid-catalyzed esterification and transesterification reactions, suitable for biodiesel production from high acid value oils, face a problem of long reaction time. In this study, we developed a two-step process for fast acid-catalyzed biodiesel production from high acid value oil in a microstructured reactor, which was assembled with an SIMM-V2 micromixer connected with a 0.6 mm i.d. stainless steel capillary. Esterification of oleic acid and transesterification of cottonseed oil with methanol were separately carried out to find suitable reaction conditions. The influences of the residence time, the methanol to acid/oil molar ratio, the catalyst concentration, the water/acid concentration and the reaction temperature were examined. The highest oleic acid conversion was obtained when esterification of oleic acid with methanol was carried out at 100 °C with the residence time of 5 min, while the highest yield of fatty acid methyl ester (FAME) was achieved when transesterification of cottonseed oil with methanol was conducted at 120 °C with the residence time of 20 min. Thereafter, a two-step process was developed based on the above reaction conditions with the first and second steps separately conducted under the esterification and transesterification reaction conditions. The results indicated that the acid value of the acid oil was reduced from 160 to 1.1 mg KOH/g with a methanol to acid molar ratio of 30, the H 2SO 4 concentration of 3 wt%, a residence time of 7 min at 100 °C in the first step. The final FAME yield reached 99.5% with a methanol to triglyceride molar ratio of 20, the H 2SO 4 concentration of 3 wt%, a residence time of 5 min at 120 °C in the second step. Therefore, biodiesel production from high acid value oil can be continuously achieved at high yields by acid-catalyzed transesterification in microstructured reactors with total reaction times of less than 15 min.

Fast Synthesis of Biodiesel at High Throughput in Microstructured Reactors

Transesterification of cottonseed oil and methanol with KOH as the catalyst for biodiesel production was carried out in microstructured reactors at residence times of less than 1 min and high flow rates. The reaction system included a micromixer that was connected to either a stainless steel capillary (inner diameter of 0.6 mm) or a PTFE tube (inner diameter of 3 mm, packed with Dixon rings) where the reaction is supposed to take place. The influences of the type of the micromixer, the residence time, the methanol-to-oil molar ratio, the flow rate, the type of delay loop, and reaction temperatures below and above the boiling point of methanol were examined. Flow patterns under different conditions were also examined in transparent microtubes. The results indicated that multilamination micromixers exhibited higher efficiencies in biodiesel production than simple T- and J-type micromixers. A higher yield of biodiesel could be obtained at reaction temperatures above the normal boiling point of methanol. By using the stainless steel capillary as the delay loop, the yield of biodiesel reached 94.8% under the conditions of a methanol-to-oil molar ratio of 8:1, a flow rate of 2.5 mL/min, a residence time of 44 s, and a reaction temperature of 70 °C. Under such circumstances, the pressure drop was 0.8 MPa. By using the PTFE tube packed with Dixon rings as the delay loop, the yield of biodiesel reached 99.5% at the same methanol-to-oil molar ratio and reaction temperature, a flow rate of 10 mL/min, and a residence time of 17 s. The pressure drop was 0.7 MPa. Thus, very fast biodiesel production at high throughput can be achieved in microstructured reactors.

Optimization of Biodiesel Production from Cottonseed Oil by Transesterification Using NaOH and Methanol

In this study, the transesterification of cottonseed oil with methanol was carried out using NaOH. The parameters, such as molar methanol:oil ratio, NaOH %, and temperature effecting the yield and biodiesel quality, were investigated to optimize biodiesel production from cottonseed oil. Below 50°C, transesterification of cottonseed oil was not completed at any molar methanol:oil ratios and catalyst percentages in 1 h. In 3:1 methanol:oil ratio, full conversion was not observed. Optimum conversion was obtained at 6:1 methanol:oil ratio and at temperatures between 50 and 60°C. Above 60°C, some difficulties were encountered in the washing step. Biodiesels that were produced at different molar methanol:oil ratios, NaOH concentrations, and temperatures were tested according to accepted standard methods and the results were compared with standard values.