Waste Cottonseed Oil Research Articles

Enhanced production of biodiesel using nanomaterials: A detailed review on the mechanism and influencing factors

The deterioration of fossil fuel supplies, combined with growing environmental concerns about fossil fuel extraction and consumption, has prompted worldwide communities to focus on renewable energy. Biodiesel production from various biomass feedstock is identified as an environmentally friendly and sustainable alternative. The application of nanomaterials as catalysts in the synthesis of biodiesel has enhanced the yield due to the selectivity. This review article is focused on the applications of potential nanoparticles in biodiesel production and their mechanism of action. The effect of operating variables, namely nanomaterial type, concentration, temperature, methanol to oil ratio, and water content on biodiesel production have been summarized. Under microwave-assisted transesterification, both sodium hydroxide and strontium oxide catalysts, produced highest yield (99%). For calcium oxide nanocatalyst, the highest biodiesel conversion obtained was 98.2% through microwave-assisted transesterification method of waste cooking oil. The optimal conditions for such a high conversion yield were methanol to oil ratio, reaction temperature, time, and catalyst loading of, 1:8, 65 °C, 76 mins, and 4 wt% respectively. The maximum biodiesel conversion yield achieved using KOH nanocatalyst was 96.44% in a microwave-assisted transesterification of waste cotton-seed cooking oil, at optimum conditions of 9.6 min, 0.65 wt% catalyst loading, and 7:1 methanol: oil ratio, respectively. Future perspectives on nanocatalysis for biodiesel production are explained.

Analysis of RSM Based BBD and CCD Techniques Applied for Biodiesel Production from Waste Cotton-Seed Cooking Oil via Ultrasound Method

Biodiesel was produced from the waste cotton-seed cooking oil with methanol in presence of the calcium oxide catalyst by the ultrasound-assisted transesterification method. The ultrasonication approach was used for biodiesel production as it significantly lower reaction time and is highly energy-efficient. This paper-work focused on the optimization of biodiesel production parameters methanol: oil molar ratio (A), CaO amount (B), process temperature (C) using the two different response surface methodology (RSM) such as box-behnken design and central composite design (CCD). Also a comparison of the results of the box-behnken design (BBD) and central composite design (CCD) has been carried out. Quadratic polynomial equations are obtained by investigating the experimental yield of the transesterification process. The impact of process parameters on biodiesel yield is discussed by various plots. It was found that the foremost influential parameter on biodiesel production was the CaO amount based on both BBD and CCD methods. A critical relationship with experimental results in BBD method R2 value is 97.73%, while within the case of the CCD method R2 value is 99.90%. The Optimized process parameters for the CaO catalyst were determined as Methanol: oil molar ratio: 12:1; CaO amount (w/w)%: 1%; reaction temperature: 50°C; and the corresponding yield: 96.45% for BBD and CCD methods, respectively.

Comparison of RSM Based FFD and CCD Methods for Biodiesel Production Using Microwave Technique

This paper deals with the optimization of reaction parameters of production of biodiesel from waste cotton-seed cooking oil (WCCO) via calcium oxide (CaO) catalyzed microwave irradiated transesterification process. The optimization of factors that affects biodiesel yield is done by applying RSM (Response surface methodology). Design-Expert software version 11 was used for optimization purpose. Present study describes the comparison of optimization results of biodiesel yield by applying RSM based Full Factorial Design (FFD) and Central Composite Design (CCD). The effect of methanol to oil ratio (M: O molar ratio) (A), CaO loading (B) and process time (C) on biodiesel yield was studied. It was found that while applying FFD method, the optimized values are 9.6:1, 1.33 (w/w %) and 9.7 min, for A, B and C respectively whereas while applying CCD method, the optimized values are 9.63:1, 1.34 (w/w %) and 9.87 min for A, B and C, respectively. From perturbation plots of FFD and CCD method analyze that the effect of CaO loading is high on the biodiesel yield. The R2 value for FFD and CCD method is 96.28% and 99.83%, respectively. The statistical analysis show that the CCD method was better than FFD method.

Renewable Hydrocarbon Production from Waste Cottonseed Oil Pyrolysis and Catalytic Upgrading of Vapors with Mo-Co and Mo-Ni Catalysts Supported on γ-Al2O3.

In this work, the production of renewable hydrocarbons was explored by the means of waste cottonseed oil (WCSO) micropyrolysis at 500 °C. Catalytic upgrading of the pyrolysis vapors was studied using α-Al2O3, γ-Al2O3, Mo-Co/γ-Al2O3, and Mo-Ni/γ-Al2O3 catalysts. The oxygen removal efficiency was much lower in non-catalytic pyrolysis (18.0%), whilst γ-Al2O3 yielded a very high oxygen removal efficiency (91.8%), similar to that obtained with Mo-Co/γ-Al2O3 (92.8%) and higher than that attained with Mo-Ni/γ-Al2O3 (82.0%). Higher conversion yields into total renewable hydrocarbons were obtained with Mo-Co/γ-Al2O3 (61.9 wt.%) in comparison to Mo-Ni/γ-Al2O3 (46.6%). GC/MS analyses showed a relative chemical composition of 31.3, 86.4, and 92.6% of total renewable hydrocarbons and 58.7, 7.2, and 4.2% of oxygenated compounds for non-catalytic bio-oil (BOWCSO), BOMoNi and BOMoCo, respectively. The renewable hydrocarbons that were derived from BOMoNi and BOMoCo were mainly composed by olefins (35.3 and 33.4%), aromatics (31.4 and 28.9%), and paraffins (13.8 and 25.7%). The results revealed the catalysts’ effectiveness in FFA decarbonylation and decarboxylation, as evidenced by significant changes in the van Krevelen space, with the lowest O/C ratio values for BOMoCo and BOMoNi (O/C = 0–0.10) in relation to the BOWCSO (O/C = 0.10–0.20), and by a decrease in the presence of oxygenated compounds in the catalytic bio-oils.

Production of biodiesel from waste bio-oil through ultrasound assisted transesterification using immobilized lipase

In this study, process intensification was carried out using lipase catalyzed transesterification of waste cottonseed oil (WCSO) with ethanol in the presence of ultrasonication. A maximum conversion of 98.7% was observed for ultrasound assisted transesterification. The optimum process conditions were ethanol to oil molar ratio of 4.5:1, a reaction temperature of 45°C, enzyme loading of 5 wt%, a reaction time of 6 h, ultrasonic amplitude of 40% and the duty cycle of 15 s ON and 15 s OFF. The influence of ultrasound makes the process efficient because of an effective reduction in reaction time to 6 h with the least catalyst dosage and power consumption. Reusability tests of the catalyst were conducted after separating the immobilized Rhizopus oryzae lipase. The regenerated lipase catalyst was found to have better reusability up to the fourth cycle and the produced biodiesel was within the ASTM D6751 standard. Furthermore, the ultrasound assisted process under mild operating conditions did not affect the immobilized enzyme. It was clearly observed that ultrasonication is faster and effective for biodiesel conversion using the immobilized lipase catalyzed transesterification reactions.

Purification and Valorization of Waste Cotton Seed Oil as an Alternative Feedstock for Biodiesel Production.

This article is focused on the production of biodiesel from the waste cotton seed oil (WCSO), after purification, as an alternative to fossil fuels. Waste oil was collected from Sodecoton, a factory producing cotton seed oil in the Far North Cameroon. The WCSO was subjected to purification using activated coal, followed by transesterification under basic conditions (potassium hydroxide (KOH)), using methanol and ethanol. Some physico–chemical properties of biodiesel, such as absorbance of waste and purified oil, density, viscosity, water content, acid value, and its energy content were determined. The result of treating the WCSO with activated coal indicated that purification efficiency of activated coal increased with the contact time and the mass of the absorbent. Absorbance results directly proved that activated coal removed unwanted components. In the same way, activated coal concentration and exposure time influenced the level of free fatty acids of WCSO. The yield of methyl ester was 97%, while that of ethyl ester was 98%. The specific gravity at 25 °C was 0.945 ± 0.0601. An evaluation of the lower calorific value (PCI) was done in order to study the energy content of biodiesel. This was found to be a value of 37.02 ± 3.05 MJ/kg for methyl ester and 36.92 ± 7.20 MJ/kg for ethyl ester. WCSO constitutes feedstock for high volume, good quality, and sustainable production of biodiesel, as well as a realistic means of eliminating the pollution resulting from the indiscriminate disposal of waste oils from both household and industrial users.

Transesterification of triglyceride over Ni impregnated Zn/CaO nanocatalysts

A series of Ni loaded Zn/CaO mixed oxides were prepared by wet impregnation process and their catalytic activities were investigated for transesterification of triglyceride. The physico-chemical properties of the catalysts were characterized by powder XRD, SEM, TEM, FT-NMR and temperature programmed desorption (TPD) studies. The prepared catalyst was successfully employed for the transesterification of waste cottonseed oil (WCO) having 4.4 wt% of free fatty acid contents. The catalytic amount of 5 wt% Ni/Zn/CaO catalyst (with respect to WCO), shown higher conversion (∼98%) of biodiesel compared to other wt% of catalysts. The catalyst was recovered from the reaction mixture by simple filtration and reused for three consecutive runs.

Investigation of ultrasound-assisted KOH and CaO catalyzed transesterification for biodiesel production from waste cotton-seed cooking oil: Process optimization and conversion rate evaluation

Development of Ultrasound (US)-assisted biodiesel production from Waste Cotton-seed Cooking Oil (WCCO) is gaining importance due to significantly lower reaction time and high energy-efficiency. In the present novel work, a comprehensive experimental study for KOH and CaO catalyzed transesterification process with detailed process optimization was performed. Kinetic modeling, scalability and energy analysis were performed to confirm the relative importance of US compared to Mechanical Stirring (MS). The optimized process parameters for KOH and CaO catalyst conditions were determined as methanol/oil molar proportion: 6.1:1 and 10.9:1, catalyst amount (w/w) %: 0.46 % and 0.96 %, reaction temperature: 53.2 °C and 48.3 °C, and the corresponding yield: 97.76 % ± 0.03 and 96.16 % ± 0.03 respectively. Box-Behnken model exhibits a significant correlation with experimental results in case of KOH (R2 = 0.98) and CaO (R2 = 0.97) catalyzed conditions. Triglyceride conversion follows pseudo-first-order reaction kinetics. The activation energy calculated for KOH and CaO catalyzed conditions was 21.36 and 33.83 kJ/mol respectively, which is 1.5 – 1.7 times lower as compared to MS process. Energy analysis showed that dissipated energy in US process is higher compared to MS. The scalability effect (with tenfold batch size), and ultrasonic duty cycle analysis showed that the continuous sonication is more effective in comparison to pulse mode. Physicochemical properties of produced biodiesel were observed in accordance with fuel specification as prescribed by ASTM D6751. Outcomes of this study are useful for development of energy-efficient US-assisted biodiesel production process on industrial scale.

Biodiesel production from waste cotton-seed cooking oil using microwave-assisted transesterification: Optimization and kinetic modeling

The current research focuses on process optimization and kinetic study of microwave-assisted transesterification process using KOH and CaO catalyst from waste cotton-seed cooking oil (WCCO). In order to enhance the biodiesel yield, process parameters: methanol to oil ratio (A), catalyst loading (B) and reaction time (C) were optimized by applying response surface methodology based on full factorial design method. It was found that for KOH catalyzed condition, the optimum values for A, B and C are 7:1, 0.65 (w/w) % and 9.6 min, respectively and the model predicted yield is 96.44%. For CaO catalyzed condition, the optimum values for A, B and C are 9.6:1, 1.33 (w/w) % and 9.7 min, respectively and the predicted yield is 89.94%. Experiments were performed using the optimized parameters and the mean biodiesel yield determined for KOH and CaO catalyzed conditions are 96.55 ± 0.23% and 90.41 ± 0.02%, respectively which shows good agreement with model predictions. Analysis of perturbation plots showed that catalyst loading is the most sensitive variable. Considering pseudo-first-order kinetic, the activation energies were obtained and found to be 13.05 kJ mol-1 and 28.93 kJ mol-1 respectively for KOH and CaO catalyzed conditions. The activation energy observed for microwave-assisted method are significantly lower compared to that of conventional method. The scale-up study (with 10 fold batch-size) and energy analysis have been done for KOH and CaO catalyzed conditions whereas reusability was performed with CaO catalyst. It was observed that up to four cycles the biodiesel yield achieved was more than 90%. In microwave-assisted process, efficency factor found to be higher as compared to conventional method. The produced biodiesel properties fulfill fuel specifications designated as per ASTM D6751 standard. The outcome of microwave-assisted transesterification study enhances biodiesel yield and significantly decreases the reaction time, thus making it energy-efficient technique.

Lithium-doped ceria supported SBA−15 as mesoporous solid reusable and heterogeneous catalyst for biodiesel production via simultaneous esterification and transesterification of waste cottonseed oil

Abstract Lithium doped ceria loaded SBA-15 has been synthesised under normal atmospheric condition (without using hydrothermal treatment) and following wet impregnation route. The catalyst has been characterised by using different techniques viz., BET method for surface area measurements, FE-SEM for surface morphology study, XPS for the determination of catalyst composition and element oxidation state. The catalyst was found to possess both acidic and basic sites and hence, successfully employed for the simultaneous esterification and transesterification of waste cottonseed oil. Under optimized reaction conditions of catalyst concentration 10 wt%, methanol to oil molar ratio of 40:1 at 65 °C, the catalyst was able to give >98% fatty acid methyl ester yield within 4 h of reaction time. The catalyst was recovered and reused during 5 successive runs without any significant loss of activity. The activation energy (Ea) for the reaction was found to be 57.7 kJ mol−1, while ΔH‡, ΔG‡ and ΔS‡ were found to be 59.4 kJ mol−1, +95.9 kJ mol−1and - 0.108 kJ mol−1, respectively. On the basis of thermodynamic parameters, the reaction is expected to be endothermic, non spontaneous and following an associative pathway.

Characterization of high acid value waste cottonseed oil by temperature programmed pyrolysis in a batch reactor

Temperature programmed pyrolysis of high acid value waste cottonseed oil (WCO) was carried out in a batch type reactor. A thermogravimetric analysis (TGA) method, which did not require a carrier gas, was used to study the properties of oil products. Weight loss data were obtained at heating rates (from 5 to 15°Cmin−1) and used to estimate the pyrolysis activation energy. A systematic study of the molecular weight distribution was made for the pyrolysis of WCO and virgin cottonseed oil at different heating rates. The yields of the products including: gases, liquids (collected pyrolytic oil), and solids (residual char) were quantified in this work. The production of pyrolysis gas was estimated during heating. The weight loss results indicated that the optimum pyrolysis rate occurred between 400 and 450°C at a heating rate of 10°Cmin−1 from room temperature to 600°C. Our work indicated that high acid value WCO yields comparatively greater volumes of gases and masses of residual products when compared to virgin cottonseed oil. After the temperature programmed pyrolysis of WCO (acid value 8.66mg KOH g−1), at a heating rate of 10°Cmin−1, the average boiling point of the pyrolytic oil was ∼349°C, which is significantly lower than that of the unprocessed WCO (456°C). The pyrolytic oil produced in this process after esterification with methanol, was found to comply with biofuel specification requirements.

Multiple variations of renal vessels – A case report

The development of the usability of a pure vegetable oil of cottonseed in diesel engines was intended in this paper. With this purpose, piston surface and valves of the test engine were coated with zirconium oxide (ZrO2) ceramic coating material in order to reduce the heat rejected from the mentioned parts. Then waste cottonseed oil was volumetrically blended with petroleum based diesel fuel by 15% cottonseed oil – 85% petroleum diesel (CO15), 35% cottonseed oil – 65% petroleum diesel (CO35) and 65% cottonseed oil – 35% petroleum diesel (CO65). Previously, the petroleum based diesel fuel with number: 2 (D2) fuel was tested in the normal uncoated single cylinder diesel engine. These blend fuels and D2 were then tested in the coated engine. Results were compared with the results of initial test of D2 in uncoated engine operation. The comparison of all the test results showed that the coating process considerably improved the performance of the test engine for all the test fuels. Besides, every measured pollutant emissions were reduced only except for oxides of nitrogen (NOx). This may certify that the coating process is a reasonable method for using pure vegetable oils in diesel engines provided that the injection process runs well for so long.

Application of ceramic coating for improving the usage of cottonseed oil in a diesel engine

The development of the usability of a pure vegetable oil of cottonseed in diesel engines was intended in this paper. With this purpose, piston surface and valves of the test engine were coated with zirconium oxide (ZrO2) ceramic coating material in order to reduce the heat rejected from the mentioned parts. Then waste cottonseed oil was volumetrically blended with petroleum based diesel fuel by 15% cottonseed oil – 85% petroleum diesel (CO15), 35% cottonseed oil – 65% petroleum diesel (CO35) and 65% cottonseed oil – 35% petroleum diesel (CO65). Previously, the petroleum based diesel fuel with number: 2 (D2) fuel was tested in the normal uncoated single cylinder diesel engine. These blend fuels and D2 were then tested in the coated engine. Results were compared with the results of initial test of D2 in uncoated engine operation. The comparison of all the test results showed that the coating process considerably improved the performance of the test engine for all the test fuels. Besides, every measured pollutant emissions were reduced only except for oxides of nitrogen (NOx). This may certify that the coating process is a reasonable method for using pure vegetable oils in diesel engines provided that the injection process runs well for so long.

Lithium zirconate as solid catalyst for simultaneous esterification and transesterification of low quality triglycerides

Alkali metal (Li, Na and K) doped zirconium oxide was prepared (Li/ZrO2, Na/ZrO2 and K/ZrO2) by wet chemical route and used as active heterogeneous catalyst for the transesterification of waste cottonseed oil with ethanol and methanol to produce fatty acid ethyl and methyl esters, respectively. The catalyst characterization supports the formation of lithium zirconate single phase in the case of Li/ZrO2 and it was able to catalyze simultaneous esterification and transesterification of high free fatty acid containing vegetable oils (VOs). The reaction conditions, such as catalyst concentration, reaction temperature, the molar ratio of alcohol/oil and stirring speed, were optimized in the presence of Li/ZrO2 catalyst. The catalyst activity was found to be a function of its basic sites which in turn depends on calcination temperature and lithium content of the catalyst. A pseudo first order kinetic equation was applied to evaluate the kinetic parameters for the transesterification of waste cottonseed oil with methanol and ethanol. The activation energy (Ea) for the Li/ZrO2 catalyzed methanolysis and ethanolysis was found to be 40.8 and 43.1kJmol−1, respectively. The catalyst could be reused up to nine cycles without significant loss of performance as >90% fatty acid alkyl ester yield was maintained.

An efficient and reusable Li/NiO heterogeneous catalyst for ethanolysis of waste cottonseed oil

In order to use ethanol in place of methanol for biodiesel production a series of Li+ impregnated NiO (Li/NiO) was prepared in nano particle form in aqueous medium without adding any organic solvent or templates. The structure of the catalyst was established by powder XRD, surface morphology, and particle size by field emission scanning and high‐resolution transmission electron microscopy studies. Basic strengths of the catalysts were measured by Hammett indicators and found to be maximum in case of catalyst prepared with 5 wt% Li+ in NiO followed by calcination at 600°C (5‐Li/NiO‐600). Catalyst characterization supported the oxidation of Ni2+ into Ni3+ upon lithium impregnation, which impart the enhanced ethanolysis activity to the Li/NiO catalyst. Under optimized reaction condition of 5 wt% catalyst, ethanol‐to‐oil molar ratio of 12:1 and at 65°C reaction temperature, >98% fatty acid ethyl ester yield was obtained in 3 h. The catalyst was found to be effective for the ethanolysis of vegetable oils (VO) having up to 8.3 wt% free fatty acids. During reusability experiments, Li/NiO catalyst was able to catalyze seven reaction cycles without major loss in activity. The ethanolysis of VO was found to follow pseudo first order kinetics and activation energy for the same reaction was found to be 74.2 kJ/mol. Thus, the present work has demonstrated the development of a “greener” and completely renewable biofuel, fatty acid ethyl esters, using waste cottonseed oil as feedstock.Practical applications: Due to high free fatty acid and water contents, homogenous catalysts could not be employed for the transesterification of waste cooking oils. The present study demonstrates the preparation of Li/NiO and its application as reusable solid catalyst for the ethanolysis of waste cottonseed oil to produce fatty acid ethyl esters.The prepared catalyst 5‐Li/NiO‐600 was able to show the ethanolysis of waste cottonseed oil during seven successive catalytic runs. Thus, catalyst was found to be effective for the preparation of renewable diesel fuel substitute, fatty acid ethyl esters.

Potassium Ion Impregnated Calcium Oxide as a Nanocrystalline Solid Catalyst for Biodiesel Production from Waste Cotton Seed Oil

Vegetable oil and animal fat derived fatty acid methyl esters are commonly known as biodiesel and provide an environment friendly and renewable substitute for the conventional diesel fuel. The present work demonstrates an easy preparation of potassium ion impregnated calcium oxide in nano crystalline form (supported by powder X-ray diffraction and transmission electron microscopic studies) and its application as a solid catalyst for the transesterification of waste cottonseed oil with methanol. The catalyst prepared by impregnating 3.5 wt% of potassium in CaO support was found to show the best catalytic activity among the prepared catalysts. The same catalyst was found to be effective for the complete transesterification of less expensive feedstock, waste cotton seed oil, even in the presence of 10.26 wt% moisture and 4.35 wt% free fatty acid contents. The selected catalyst has also been reused successfully for three catalytic cycles. Few physicochemical properties of the prepared biodiesel sample have been studied and found to be within the acceptable limits of EN 14214 standards.

Potassium fluoride impregnated CaO/NiO: An efficient heterogeneous catalyst for transesterification of waste cottonseed oil

Potassium fluoride impregnated CaO/NiO has been prepared by wet impregnation method in nano particle form as supported by powder XRD, scanning electron microscopy, and transmission electron microscopy studies. Brunauer–Emmett–Teller surface area and basic sites measurement studies have been performed to establish the effect of potassium fluoride impregnation on catalyst surface morphology and basic strength. CaO/NiO impregnated with 20 wt% potassium fluoride was used as solid catalyst for the transesterification of waste cottonseed oil having up to 5.8 wt% free fatty acid content. The variables used for the transesterification were, KF impregnated on CaO/NiO, catalyst concentration, reaction temperature, and methanol to oil molar ratio. Reaction parameters have been optimized to achieve the least reaction period for the completion of the reaction. Complete transesterification (>99% FAMEs yield) of waste cottonseed oil with methanol (1:15 molar ratio) required 4 h in the presence of 5 wt% catalyst (with respect to oil) at 65°C. Reusability study suggests that catalyst could be recycled for four successive runs without significant loss in activity. A pseudo first order kinetic equation was applied to evaluate the kinetic parameters and under optimized conditions first order rate constant and activation energy was found to be 0.023 min−1 and 41.2 kJ/mol, respectively. Few physicochemical properties of the prepared biodiesel sample have also been studied and compared with standard values.Practical applications: In India, application of edible vegetable oils for biodiesel production is prohibited to avoid food versus fuel situation. Application of waste cottonseed oil (WCO) for biodiesel production could circumvent this problem. However, homogeneous alkali catalyst could not be employed due to the presence of high free fatty acid contents in such feedstock. In this context present study demonstrates the impregnation preparation of KF impregnated CaO/NiO and its application as reusable solid catalyst for the transesterification of WCO.

Characterisation of Biodiesel Derived From Waste Cotton Seed Oil and Waste Mustard Oil

Biodiesel, an alternative fuel is derived from the fats of animals and plants. As energy demand increases and fossil fuels are limited, research is directed towards alternative renewable fuels. Properties of waste oil (cotton seed oil and mustard oil) have been compared with the properties of petrodiesel, showing a comparable regime for satisfactory optimized blend which is to be selected for the better performance of a C.I. engine with biodiesel. The work presented in this paper is the study of characteristics of biodiesel prepared from vegetable oils (waste cotton seed oil and waste mustard oil). The characteristics of biodiesel are to be checked at different blends(B10, B15, B20) and select the optimum blend based on these characteristics. The characteristics include free fatty acid value, density, viscosity, flash point and fire point, cloud point and pour point, carbon residue content and ash residue content.

Ethanolysis of waste cottonseed oil over lithium impregnated calcium oxide: Kinetics and reusability studies

A series of Li/CaO catalysts has been prepared by impregnating 0.5–5.0 wt% Li in CaO by wet chemical method. Prepared Li/CaO catalysts have been characterized by powder X-ray diffraction, scanning electron and transmission electron microscopy and Brunauer–Emmett–Teller (BET) surface area studies, in order to establish the structure and surface morphology of the catalyst. Hammett indicator test study was performed to determine the basic strength of the Li/CaO catalysts. The prepared Li/CaO catalysts have been employed as a heterogeneous catalyst for the transesterification of waste cottonseed oil (having 2.8 wt% free fatty acid contents) with ethanol. Under optimal reaction conditions viz., ethanol/oil molar ratio of 12:1, catalyst to oil weight fraction of 5% and 65 °C reaction temperature, 98% fatty acid ethyl ester yield was obtained in 2.5 h of reaction duration. Under the optimized reaction conditions, the pseudo first order constant and Arrhenius activation energy were found to be 0.03 min−1 and 70.0 kJ mol−1, respectively. Further Li/CaO catalyst was also found to be effective for the ethanolysis and methanolysis of vegetable oils having up to 3.4 wt% free fatty acids. The use of 3-Li/CaO catalyst is advantageous considering that it not only utilizes waste cottonseed oil as a feedstock, but also renewable and nontoxic alcohol, ethanol, for the biodiesel production.

Preparation of solid acid catalyst from glucose–starch mixture for biodiesel production

The aim of this work is to study the catalyst prepared by glucose-starch mixture. Assessment experiments showed that solid acid behaved the highest esterification activity when glucose and corn powder were mixed at ratio of 1:1, carbonized at 400°C for 75 min and sulfonated with concentrated H(2)SO(4) (98%) at 150°C for 5 h. The catalyst was characterized by acid activity measurement, XPS, TEM and FT-IR. The results indicated that solid acid composed of CS(0.073)O(0.541) has both Lewis acid sites and Bronsted acid sites caused by SO(3)H and COOH. The conversions of oleic acid esterification and triolein transesterification are 96% and 60%, respectively. Catalyst for biodiesel production from waste cottonseed oil containing high free fatty acid (FFA 55.2 wt.%) afforded the methyl ester yield of about 90% after 12h. The catalyst deactivated gradually after recycles usage, but it could be regenerated by H(2)SO(4) treatment.