Esterification Of Waste Cooking Oil Research Articles

Adsorption study of isotherms, kinetics modelling, and thermodynamics of immobilized Candida rugosa lipase on metal oxide for esterification of waste cooking oil

The problem regarding improper disposal of waste cooking oil (WCO) can be solved via biotransformation of WCO to value added product using lipases as a biocatalyst. Thus, immobilization method was proposed for the recyclability of the biocatalyst. However, a comprehensive discussion on adsorption study is limited for lipase immobilization. In this study, Candida rugosa lipase (CRL) was immobilized on modified metal oxide (Mg2+/Al2O3) and the support was improved by addition of activating agent (L-lysine/Mg2+/Al2O3). Subsequently, the biocatalysts were used for esterification of WCO in the presence of methanol. Maximum adsorption capacity for the support was improved after addition of L-lysine resulting in 0.262 mg protein/g of support. The equilibrium adsorption data for both systems were fitted to the Redlich Peterson isotherm model while the kinetics study was most fitted with Elovich model, and the adsorption process were influenced by intraparticle and film diffusion mechanisms. Thermodynamic analysis explained that the adsorption process of CRL/L-lysine/Mg2+/Al2O3 was more spontaneous and stronger as compared to CRL/Mg2+/Al2O3. Furthermore, CRL/L-Lysine/Mg2+/Al2O3 exhibited its potential in esterification of WCO by converting 62.95% of free fatty acid (FFA), while CRL/Mg2+/Al2O3 converted lower FFA (53.62%). This study offers a fundamental understanding on designing an effective immobilization system by addition of activating agent to develop a good biocatalyst for biotransformation of WCO.

Corncob-Derived Sulfonated Magnetic Solid Catalyst Synthesis as Heterogeneous Catalyst in The Esterification of Waste Cooking Oil and Bibliometric Analysis

A corncob-derived magnetic solid acid catalyst was synthesized through the sulfonation method and an impregnation process, respectively. In the sulfonation process, the concentrated H2SO4 was utilized as an activation agent to obtain acidic properties. The solution of ferric sulphate-ferrous sulphate was utilized for impregnation to generate the magnetic behaviour of the material. The prepared magnetic acid solid catalyst had a high saturation magnetisation value of 16.48 emu/g and a total acidity of 1.43 mmol/g. The performance of the catalyst was evaluated in the esterification reaction of waste cooking oil. The best result presented 86.12% FFA conversion under reaction conditions of 5% catalyst loading and a 1:15 oil-to-methanol molar ratio at 60oC for 4 h. The catalyst was separated magnetically from the reaction solution and exhibited a good reusability with 61% remaining active after 5 consecutive cycles of reaction. This study resulted in a promising method to obtain magnetic-sulfonated carbon-based catalyst from corncob residue, and it is economical potentially and environmentally friendly for the esterification of low-quality feedstock for biodiesel production.

Biodiesel Production from Waste Cooking Oil via β-Zeolite-Supported Sulfated Metal Oxide Catalyst Systems.

Waste cooking oil (WCO) is a readily available and cheap feedstock for biodiesel production. However, WCO contains high levels of free fatty acids (FFAs), which negatively impact the biodiesel yield if homogeneous catalysts are used. Heterogeneous solid acid catalysts are preferred for low-cost feedstocks because the catalysts are highly insensitive to high levels of FFA in the feedstock. Therefore, in the present study, we synthesized and evaluated different solid catalysts, pure β-zeolite, ZnO-β-zeolite, and SO42-/ZnO-β-zeolite for the production of biodiesel using WCO as feedstock. The synthesized catalysts were characterized by Fourier transform infrared spectroscopy (FTIR), pyridine-FTIR, N2 adsorption-desorption, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy, while the biodiesel product was analyzed using nuclear magnetic resonance (1H and 13C NMR) and gas chromatography-mass spectroscopy. The results revealed that the SO42-/ZnO-β-zeolite catalyst showed excellent catalytic performance for simultaneous transesterification and esterification of WCO, with a higher percentage conversion than the ZnO-β-zeolite and pure β-zeolite catalyst, due to the large pore size and high acidity. The SO42-/ZnO-β-zeolite catalyst exhibits 6.5 nm pore size, a total pore volume of 0.17 cm3/g, and high surface area of 250.26 m2/g. Experimental parameters such as catalyst loading, methanol:oil molar ratio, temperature, and reaction time were varied in order to establish the optimal parameters. The highest WCO conversion of 96.9% was obtained using the SO42-/ZnO-β-zeolite catalyst under an optimum reaction condition of 3.0 wt % catalyst loading, 200 °C reaction temperature, and 15:1 molar ratio of methanol to oil in 8 h reaction time. The WCO-derived biodiesel properties conform to the ASTM6751 standard specification. Our investigation of its kinetics revealed that the reaction follows a pseudo first-order kinetic model, with an activation energy (Ea) of 38.58 kJ/mol. Moreover, the stability and reusability of the catalysts were evaluated, and it was found that the SO42-/ZnO-β-zeolite catalyst exhibited good stability, giving a biodiesel conversion of over 80% after three synthesis cycles.

Synthesis of superacid sulfated TiO2 nanowires for esterification of waste cooking oil

Synthesis of superacid sulfated TiO2 nanowires for esterification of waste cooking oil

소형 디젤기관에서 Waste Cooking Oil 바이오디젤 혼합유가 기관성능 특성에 대한 실험적 분석

The purpose of this study is to evaluate the feasibility of used waste cooking oil as an alternative fuel in diesel engines. In this work, biodiesel was produced from lipase-catalyzed hydrolysis of waste cooking oil (WCO) followed by esterification of the hydrolyzed WCO. The hydrolysis of acylglycerin was carried out at 30°C in sodium and the esterification of WCO was carried out at 40°C with methanol in a solvent hydroxide medium. In this study, waste cooking oil was prepared to waste cooking oil generated from the franchise chicken stores, and applied to a diesel engine to confirm the possibility and cost-effectiveness of biodiesel waste cooking oil. The results showed that WCO is a promising feedstock for use in the production of biodiesel. As a result, biofuels of used waste cooking oil showed slightly higher of specific fuel consumption, and NOx. As carbon monoxide and soot were decreased, also decreased pressure was decreased but the rate of pressure rose.

Optimization studies on esterification of waste cooking oil using sulfated montmorillonite clay acidic catalyst

Currently, refined edible oils are used to produce biodiesel with the help of a base catalyst. The most important problem with the base-catalyzed esterification process is that they produce soap when they have higher free fatty acids (FFA). The present study indicates that montmorillonite (k10) can be a significant catalyst prepared by the impregnation method using H2SO4 in the ratio of 1:5. The prepared novel catalyst was characterized using XRD, FTIR and SEM-EDS techniques. The optimum conditions for esterification have been determined by applying RSM with CCD methodology for each significant variable like oil-methanol molar ratio, catalyst amount, reaction time and temperature. The optimum acid conversion of 80.8% was observed at an oil-methanol molar ratio of 1:12, amount of catalyst 6 wt% and 120 min of reaction time at 55 °C.

Transesterification of Waste Cooking Oil to Produce A Sustainable Rejuvenator for Aged Asphalt

This study examines the merits of esterification of waste cooking oil to reduce its acidic content for use as a rejuvenator for aged asphalt. It further examines how acidic compounds in bitumen increases the moisture susceptibility of bituminous composites made from siliceous stones and bitumen. While some acidic compounds are inherent in bitumen, the recent widespread use of bio-modifiers such as waste cooking (vegetable) oil has further increased the acidic compounds in bio-modified bitumen. Acidic compounds adsorb well to siliceous stones, but they are easily replaced by water molecules, giving rise to moisture damage. It was found that a reduction or removal of the acidic compounds of waste cooking oil via transesterification significantly enhances its resistance to moisture damage. The study results showed that treated waste cooking oil is not only a promising rejuvenator to be used with aged bitumen, but also quite resistant to moisture damage. It was also found that transesterification reduces the acid value of bitumen from 12 to 0.27 (mg KOH/g). This turned a moisture-susceptible bitumen to nearly a moisture-resistant bitumen as evidenced by nearly no change in moisture-induced shear thinning after 24hr water conditioning. The outcome of the study shows significant role of acidic compounds in moisture damage, and the importance of accounting for the acidity of rejuvenators to ensure their durability. The study results confirm the feasibility of tuning waste cooking oil to a sustainable asphalt rejuvenator to promote both resource conservation and asphalt recycling.

Potassium and 12‐tungstophosphoric acid loaded alumina as heterogeneous catalyst for the esterification as well as transesterification of waste cooking oil in a single pot

AbstractTo prepare the heterogeneous catalyst for the simultaneous transesterification and esterification of waste cooking oil (WO), 12‐tungustophosphoric acid (TPA) and K+ were loaded over alumina. The catalyst structure was confirmed by powder X‐ray diffraction analysis while the catalyst composition and the elemental oxidation state by X‐ray photoelectron spectroscopic study. The surface morphology of the catalyst was established by high‐resolution transmission electron microscopy. The temperature‐programmed desorption study supports the existence of basic and acidic sites over the catalyst surface owing to the presence of potassium oxide and TPA, respectively. Underneath the optimized conditions for reaction, that is, 10 wt% of catalyst with respect to oil, 9:1 methanol to oil molar ratio and 65°C reaction temperature, 97% fatty acid methyl ester (FAME) yield was obtained within 1.25 h of reaction time. The catalyst was recovered from the reaction mixture via centrifugation and reused in four consecutive runs. Moreover, the presence of high moisture (4 wt%) and free fatty acid (7.8 wt%) contents was not found to have any adverse effect on the catalyst activity. To demonstrate the catalyst stability, the metal content in the reaction mixture was analyzed, and total metal content was found to be less than 2 ppm to hold the catalyst stability. The kinetic study suggests that the reaction follows (pseudo) first‐order kinetic equation with the prepared catalyst.

Development of two-step noncatalytic esterification of waste cooking oil for biodiesel preparation

An innovative two-step noncatalytic esterification technique was proposed to synthesize alkyl esters from free fatty acids simulated in waste cooking oil, as a pretreatment process for biodiesel production, without adding any catalyst under normal conditions of pressure and temperature. The effect of methanol:oil molar ratio, reaction time, mixing rate, and reaction temperature were investigated. The results confirmed that the conversion of the reaction was increased when increasing the methanol molar ratio and decreased in prolonged reaction temperature. High conversion (94.545%) was successfully achieved at optimized conditions of 115:1, 65:1 methanol:oil molar ratio in the first step and second step, respectively, other conditions in both steps were found to be 9 s reaction time, 450 rpm mixing rate, and 62 °C reaction temperature by response surface methodology central composite design. Noncatalytic esterification, which eliminates the complications corresponding with catalyst utilization such as additional cost, time-wasting, and separation requirements, could be considered as a promising pretreatment technique to reduce the high acidity of waste cooking oil to the acceptable limit of 1 mg KOH/g oil or less in two steps, for biodiesel synthesize.

Production of biodiesel from waste cooking oil using heterogeneous catalysts KI/γ-Al2O3

Biodiesel is a promising alternative fuel that can be produced from vegetable oil through the esterification process. Conventional homogeneous acid or base catalysts result in a lower biodiesel yield and a longer reaction time and require separation from the product, which lead to inefficient production. This research was aimed at utilising the heterogeneous catalyst potassium iodide (KI)/γ-aluminium oxide (γ-Al2O3) for esterification of waste cooking oil into biodiesel. The catalyst was prepared using the impregnation method in which calcination was conducted at 500°C for 3 h. The esterification operation condition was set to a temperature of 65°C for 3 h and a molar ratio of oil to methanol of 1:14. Moreover, the heterogeneous catalyst was compared with a homogeneous catalyst with respect to the yield of biodiesel. The results showed that at a 2% (g catalyst/g oil) catalyst concentration, the esterification using the catalyst KI/γ-Al2O3 produced a higher yield of biodiesel (88·03%) compared with using γ-aluminium oxide (58·86%) and a conventional catalyst (82·23%). The reusability study of the catalyst KI/γ-Al2O3 showed that after the first reuse, the catalyst could still produce biodiesel with a yield of 61·30%. After the second reuse, the yield of biodiesel was 52·61%, and the third reuse produced a yield of 21·50%.

Esterification of Waste Cooking Oil using Heterogeneous Catalyst from Pearl Shell

Biodiesel is a renewable and environmentally friendly energy source. The process of using a homogeneous catalyst has several disadvantages, such as: removing a lot of waste water from washing the catalyst residue and cannot be reused. This catalyst is also low in corrosion and is more environmentally friendly. The purpose of this study was to study the preparation of heterogeneous catalysts from pearl shells applied to the cooking oil esterification reaction. The oil was then characterized by the XRD, XRF, SEM, and FTIR. The results of GCMS for reaction without catalysts yield only 27.07% by weight of alkyl ester, whereas using a catalyst is 93.4%. The influence of time, in the 60th minute, was the optimal time for the esterification reaction, and the effect of the weight of the catalyst which was 1% the optimal weight. This shows that pearl oyster shell catalyst can act as an esterification catalyst for used cooking oil and can be used as an alternative to a homogeneous catalyst substitute catalyst.

ESTERIFIKASI DAN DEASIDIFIKASI MINYAK JELANTAH PADA PEMBUATAN BIODIESEL MENGGUNAKAN KATALIS ABU TONGKOL JAGUNG

Esterification and deacidification of waste cooking oil using alkali neutralization for biodiesel production using corncob ash as an alternative base catalyst was carried out. This study aimed to attainone of the desired transesterification conditionsby reducing free fatty acids content of waste cooking oil. Esterification was carried out by reacting waste cooking oil and methanol with certain volume ratio and acid catalyst (H2SO4) at 50oC for 4 hours. Deacidification was carried out by adding 0.5 N NaOH solution (15% excess alkali) at 60oC for 30 minutes. Esterification of waste cooking oil using acid catalyst before transesterification with corn cobs ash catalyst significantly increased the efficiency of free fatty acid conversion (92.69%) under volume ratio of 25% methanol /oil and 0.5% acid catalyst for 4 hours reaction. Deacidification of esterified oil with FFA content of 2.29 mg KOH /g oil through alkali neutralization at 55oC using alkaline content of 0.8 N reduces free fatty acid content to 0.47 mg KOH /g oil. Transesterification results showed that biodiesel component of waste cooking oil was dominated by polyunsaturated fatty acids (linoleic acid / C18-2), monounsaturated fatty acids (palmitic acid / C16-1 and oleic acid / C18-1) and saturated acids (palmitic / C16-0 and stearic acid / C18-0). Most of the biodiesel products were similar to those of the diesel physical characters. Biodiesel made of waste cooking oil meets the biodiesel quality standard (SNI 7182: 2015) for such parameters of density, viscosity, acid number, saponification value, iodine number and cetane. Esterification and neutralization process are effective in reducing free fatty acids content of waste cooking oil before being used in transesterification with corn cobs ash catalyst.
 Keywords: esterification, neutralization, alkali, waste cooking oil, biodiesel, corn cobs ash

Esterification of high FFA content waste cooking oil through different techniques including the utilization of cement kiln dust as a heterogeneous catalyst: A comparative study

The aim of this work was to compare two different techniques for the esterification of waste cooking oil having high free fatty acids (FFA) content. The first method was esterification using sulfuric acid as the catalyst, wherein the effect of methanol to oil molar ratio and catalyst loading were studied and optimized via response surface methodology (RSM). The optimum conditions were molar ratio 52:1 and catalyst loading 3.5%, and the observed conversion of FFA to methyl esters was 96.2%, after 1 h, at 65 °C. The second method was heterogeneously catalyzed esterification using cement kiln dust (CKD). In this case, the optimum conditions were: esterification time 6 h, methanol to oil molar ratio 18:1, catalyst loading 2%, and 65 °C leading to 98.8% conversion. A comparison between the two methods revealed that using CKD can be a potentially economical catalyst more than using a homogeneous catalyst.

Use of hydrodynamic cavitation for esterification of free fatty acids in waste cooking oil

Esterification followed by transesterification process is widely applied for biodiesel production from oil with high free fatty acids (FFA) content to remove the FFA and increase the yield of biodiesel. The aim of this research was to study the esterification of waste cooking oil using the hydrodynamic cavitation apparatus. Waste cooking oil with initial FFA content 4.33% was esterified with methanol using sulfuric acid 1%-w/w as the catalyst. The reaction condition was kept constant for 120 minutes of total reaction time. At the best operating condition i.e. molar ratio of waste cooking oil to methanol 1:10 and reaction temperature 50 °C, the initial FFA of waste cooking oil 4.33% reduced to 0.76%. The experimental results also showed that the hydrodynamic cavitation had better performance than the conventional process using mechanical stirring.

Study on kinetics-thermodynamics and environmental parameter of biodiesel production from waste cooking oil and castor oil using potassium modified ceria oxide catalyst

Abstract Research on biodiesel production from waste material and lignocellulosic biomass using heterogeneous catalyst has been studied throughout the world to achieve a sustainable source of fuel. Heterogeneous base-catalyzed transesterification attracts more attention as it overcomes the flaws regarding homogeneous catalysis. In this study, potassium (K) modified ceria oxide (CeO2) was synthesized via auto combustion method and introduced as the heterogeneous base catalyst for transesterification of waste cooking oil and castor oil. It was found that catalyst having K/Ce atomic ratio 2, activated at 800°C showed highest efficiency of 99.09% and 98.49% FAME (fatty acid methyl ester or biodiesel) conversion in methyl esterification of waste cooking oil (WCO) and castor oil (CO) under moderate reaction condition. A robust base-catalyzed transesterification reaction mechanism was proposed based on FTIR result. The rate constants (kC) of the reaction at five different temperatures 45 to 65°C with 5°C interval were evaluated by mean of respective kinetic plots for methyl esterification of WCO and CO. Activation energy Ea for WCO and CO transesterification were calculated to be 50.1 kJ mol−1 & 48.55 kJ mol−1 with corresponding frequency factor 35.4 × 105 min−1 & 11.9 × 105 min−1. Enthalpy of activation (ΔH#) was obtained to be 47.35 kJ mol−1 and 45.989 kJ.mol−1with corresponding entropy of activation (ΔS#) −128.69 J.K−1. mol−1 and -137.21 J.K−1. mol−1 of methyl ester formation of WCO and CO. The Gibb’s free energy of activation (ΔG#) for both reactions was evaluated to be 90.85 kJ mol−1 and 92.66 kJ mol−1. The positive values of both ΔG# and ΔH# indicates that the reaction followed an endothermic non-spontaneous pathway while the negative ΔS# value informs the reduction in randomness during transesterification. The catalyst showed high turnover frequency and meager value of Environmental-factor which implies the catalyst is well efficient for fast production of biodiesel with minute waste generation.

Aluminum foil waste as catalyst for esterification of waste cooking oil

ABSTRACT In this study, aluminum chloride hexahydrate (AlCl3.6 H2O) was derived from aluminum foil waste as a heterogeneous acid catalyst in the esterification of waste cooking oil. The parameters of catalyst loading (2–8 wt%), ultrasonic frequency (12–40 kHz), and reaction time (15–60 min) were optimized for maximum biodiesel yield production. Under constant condition of methanol to oil molar ratio of 6:1 and temperature of 50°C, a biodiesel yield of 91% was obtained at 2 wt% catalyst loading, 26 kHz ultrasonic frequency, and 40 min reaction time.

A core-shell SO4/Mg-Al-Fe3O4 catalyst for biodiesel production

Catalytic transesterification of triglycerides and esterification of free fatty acids underpins sustainable biodiesel production, wherein efficient heterogeneous catalysts are sought to replace mineral acids. A robust, magnetic core-shell SO4/Mg-Al-Fe3O4 catalyst was synthesised by stepwise co-precipitation, encapsulation, and surface functionalisation. The resulting magnetically-separable catalyst has a surface area of 123 m2 g−1, uniform 6.5 nm mesopores, and a high total acid site loading of 2.35 mmol g-1. Optimum conditions for the (trans)esterification of waste cooking oil (WCO) over the sulfated solid acid catalyst were 95 °C, a methanol:WCO molar ratio of 9:1, and 300 min reaction to achieve 98.5% FAME yield. Esterification of oleic acid to methyl oleate resulted in an 88% yield after 150 min under the same reaction conditions. The magnetic solid acid catalyst exhibited good thermal and chemical stability and enabled facile catalyst separation post-reaction and the production of high quality biodiesel.

Heterogeneous Esterification of Waste Cooking Oil with Sulfated Titanium Dioxide (STi)

In this work, a sulfated titanium dioxide (STi) catalyst obtained from a commercial TiO2 precursor was synthesized and characterized. The catalyst was sulfated by the simple impregnation method with H2SO4 and subsequently calcined at different temperatures. The synthesized catalyst was characterized by X-ray Diffraction (XRD), Energy-Dispersive Spectroscopy (EDS), and Scanning Electron Microscopy (SEM). The sulfated catalyst was thermally treated at different temperatures (100, 200, 400, and 600 °C) and evaluated in oleic acid esterification reactions by varying the concentration of the catalyst during the conversion of oleic acid to methyl oleate. The conversion was measured from the variation of the acid index (AI)° and free fatty acids (FFA) during the reaction. The STi catalyst obtained was compared with two homogeneous catalysts, H2SO4 and ferric sulfate [Fe2(SO4)3], evaluating the reaction time in the conversion, from which improvements in the reaction performance of the catalyst synthesized in this work were observed versus the two homogeneous catalysts mentioned earlier. Catalyst reuse cycles were also evaluated as well as their performance in the esterification of waste cooking oil. The best catalyst yields reached values close to 86% in a reaction time of 6 h.

Esterification of Waste Cooking Oil Using Ultrasonic: Kinetic Study

Waste cooking oil (WCO) have a great potential as an alternative raw material for producing biodiesel. The literatures kinetic of the esterification of WCO in the presence of phosphoric acid catalyst with ultrasonic assisted are rare and most literatures used conventional method. This study aims to determine the optimum condition and the parameters of first and second order kinetics of the WCO esterification which was assisted by ultrasonic bath. Variables that used in this study are methanol/oil mole ratio, acid catalyst concentration and reaction temperature. The highest conversion was 42.08% with methanol/oil mole ratio of 15:1, a catalyst (phosphoric acid) concentration of 9% wt and temperature of 50oC within 90 minutes. The reaction time was reduced to 3 times (minute) compare to conventional method and fatty acid reduced 42%. Kinetic parameters were calculated with assumption that the esterification was the irreversible reaction. The reaction rate constant increasing with temperature. The value of activation energy for esterification of WCO is 42.94 kJ/mol for first order reaction and 35.30 kJ/mol for second order reaction.

Biodiesel Production from Waste Cooking Oil using Electrostatic Method

Biodiesel (methyl ester) produced from trans esterification of waste cooking oil is a potential material to replace diesel fuel. The biodiesel can be obtained by using electrostatic method equipped with fixed distance electrode 1.5 cm and voltage at 12 volts. Coagulation of particle process i.e. glycerin drops in biodieselglycerin mixture was based on electrical field. Reactants used were methanol over KOH catalyst and temperature was set at 60 C. The residence time was varied as well as methanol to waste cooking oil ratio. Analysis result shows the process was able to obtain yield up to 83.3%. The quality of biodiesel produced was tested and satisfy the requirement according to National Standard of Indonesia (SNI), i.e. density 0.8594 mg/mL (compared to SNI: 0.85-0.90 mg/mL), flash point 191 C (SNI min 100 C), water content 0.0342% (SNI max 0.05%) and viscosity at lower limit 2.31 cSt. According to SNI 7182-2015 the above value meets the specified standard.