Catalytic Transesterification Research Articles

Waste‐Derived Catalyst for Biodiesel Manufacturing in CO2‐Free Manner: Preparation, Catalytic Activity and Reuse Studies

Currently, CaO‐based catalysts for biodiesel manufacturing are produced by calcination of available limestone ore consisting of CaCO3. The production of 1 ton of CaO catalyst resulted in 0.89 tons of CO2 emission, and every ton of the catalyst provided only 20 tons of biodiesel in non‐reusable manner. In this work, a CaO‐based catalyst was obtained by calcination of Ca(OH)2, a large‐tonnage waste from acetylene manufacturing via calcium carbide route (carbide slag), producing H­2O as a by‐product instead of CO2. Amazingly, carbide slag – a waste – was active in catalytic transesterification of soybean oil skipping calcination or any pretreatment steps and provided biodiesel in 28% yield! Moreover, biodiesel was obtained in 98% yield after catalyst calcination at 600 °C for at least 4 times accompanying zero CO2 emission. The obtained catalysts were characterized by XRD, XRF, FTIR, TGA, SEM‐EDX and BET surface area analysis. The best conversion of soybean oil was achieved using 1 wt% CS600, MeOH:oil ratio of 12:1, by boiling at 65 °C for 2 h. The catalyst reuse was found out using two approaches: "catalyst isolation" (5 cycles with yield ≥ 80%) and "fresh start" (up to 7‐10 cycles with yield ≥ 80%).

Sustainable biodiesel production from waste cooking oil using highly effective CaO/hectorite catalyst: Process optimization, kinetic and thermodynamic studies.

Biodiesel production through trans-esterification reaction requires design of efficient solid catalyst for sustainable use. This study reports a newly prepared CaO/hectorite catalyst for trans-esterification reaction of waste cooking oil (WCO). The catalyst material was prepared by wet impregnation method. Material characterization was done using various advanced instrumentation techniques such as FTIR, 1H/13C NMR, XRD NMR, BET, TGA and FE-SEM. The result of FE-SEM characterization shows the surface heterogeneity in catalytic material. Further, an enhanced BET surface area (142.3 m2 g−1) of CaO/hectorite indicated suitability of material for catalytic applications. Kissinger-Akahira-Sonuse (KAS) computational model was used to evaluate thermodynamic parameters. Response surface methodology (RSM) – Box Behnken model/ANOVA was used to draw the 3D-surface plots and 2D-contour plots for estimation of maximum biodiesel yield. The catalytic trans-esterification shows high biodiesel production (95 %) in an optimized reaction condition (10.5:1 methanol:oil molar ratio, 3.5 % catalyst loading, 57.5 °C reaction temperature and 105 min). It was found that the biodiesel produced from WCO has fuel characteristics complied with that of B100. The catalyst could be reused up to seven consecutive cycles operation resulting biodiesel production (>80 % yield) thus indicating future commercial applications in a sustainable manner.

Transesterification of Azadirachta indica seed oil into biodiesel using MgO-supported tri-metallic catalyst– synthesis and characteristic evaluation

Environmentally sustainable biodiesel from non-edible waste Azadirachta indica (neem) seed oil provides an economical alternative to combat issues caused by fossil fuel combustion. The current study reports specifically a bi-functional trimetallic (Ca-Sr-Mo) catalyst delineated across MgO support synthesized via wet impregnation and green synthesis route using Cassia fistula extract. In FTIR analysis, peaks appeared at 992, 1390, 1424 cm−1 represent the C–O stretching, C–H deforming and M–O–M bending deformation vibrations, respectively. The diffraction peaks of all CaO, SrO, MoO2, and MgO in the XRD pattern represent the formation of catalysts. The prepared catalyst is employed in the transesterification reaction to convert A. indica oil into fatty acid methyl ester. The study used the response surface methodology to examine factors that could affect the conversion rate, including oil-methanol molar ratio, reaction time, and catalyst loading. The results were analyzed to determine the best combination of factors that yields the optimal catalytic transesterification process. The highest yield of 89.92 % was achieved under optimum conditions of methanol-to-oil (18:1), catalyst loading (5 wt%), and time (6 h). In FTIR analysis, the new peak appeared at 1160 cm−1, indicating the formation of methyl esters, while 1H NMR analysis confirmed the successful conversion of A.indica oil into FAMEs by the appearance of strong singlet at 3.66 ppm for methoxy proton.1H NMR also indicated a high yield (90.09 %) which is comparable to RSM obtained yield. Additionally, a reaction mechanism has been proposed. Specifically, GC-MS FAME profiles and physicochemical testing confirmed that biodiesel meets ASTMD6751 and EN14214 standards with key fatty acid methyl esters and desirable properties.

Lewis Acid-Base Site-Assisted In Situ Transesterification Catalysis to Produce Biodiesel

Biodiesel, a potent replacement for petroleum diesel, is derived from fatty acids in biomass through transesterification, which is renewable, non-toxic, and biodegradable and is a powerful replacement for petroleum diesel. Lewis acid has been proven effective for esterification and transesterification. The Lewis base enhances the electrophilic and nucleophilic properties of the molecules that bind to it, leading to the remarkable versatility of the Lewis base catalytic reaction. Many studies have shown that Lewis acid/base catalyzed in situ transesterification is a fast and environmentally friendly method for producing biodiesel. The utilization of Lewis acid-base sites to catalyze transesterification has been shown to enhance their efficiency and utilization of acid-base active sites. This review explores biodiesel production by different catalysts using Lewis acid-base sites, the conditions for catalytic transesterification, the effects of different reaction parameters on biodiesel production, and the biodiesel production process.

Sustainable Biodiesel Production via Biogenic Catalyzed Transesterification of Baobab Oil Methyl Ester and Optimization Process

Biomass diesel is one of the sustainable and renewable sources of energy envisaged to hold a prominent position in the world energy infrastructure. In this study, biodiesel was production from baobab seed oil by transesterification using biogenic heterogeneous catalyst, derived from mixed wastes of white chicken eggshells and banana fruit peels. The production process was analyzed and statistically analyzed using Box-Behnken Design-Response Surface Methodology (BBD-RSM). The influential transesterification reaction parameters investigated with their ranges include reaction time (40–80 min), molar ratio of oil to methanol (1:9–1:15) and catalyst weight (3–5 wt%). The nano-catalyst (CaO-BFP-850 NPs) was prepared by calcination at high temperature of 850 °C for 4 h, and its properties were found to contain majorly the basic elements of Ca and K when investigated with analytical instruments such as SEM, EDS, DSC-TGA, FT-IR, and XRD. The regeneration test of the CaO-BFP-850 NPs conducted showed it could be reused for more than four cycles with less catalytic efficiency reduction. The ideal conditions instituted by BBD-RSM was 75 min of reaction time, 12.8:1 molar ratio of oil to methanol, and 4.08 wt% CaO-BFP-850 at 65 °C and 650 rpm constant temperature and agitation speed respectively, with the validated biodiesel yield of 96.70 wt%. The assessment of the quality of the biodiesel produced showed compliance with the standard specifications of ASTM D6751, EN 14241, and SANS 833.

Strategic approach for converting fat-rich food waste into high-quality biodiesel using black soldier fly larvae for sustainable bioenergy

Food waste (FW) comprises carbohydrates, proteins, lipids, and water, posing technical challenges for effective treatment and valorisation. This study addresses these challenges by using black soldier fly larvae (BSFL) as a bioconversion medium to transform FW into biodiesel (BD). BSFL predominantly consumed the carbohydrates and proteins in FW (81 wt%), while showing a lower preference for lipids (<50 wt% consumed). Notwithstanding the lower consumption of lipids in the FW than that of carbohydrates and proteins, BSFL had a high lipid content (48.3 wt%). The subsequent conversion of the lipids extracted from BSFL into BD was tested via catalytic (acid/alkali) and non-catalytic transesterification processes. The BD yield from catalytic transesterification was lower than that from non-catalytic transesterification because of the low tolerance against free fatty acids (FFAs). BD was also produced from the lipid-concentrated residual FW through non-catalytic transesterification. Although the FW residue extracts contained high amounts of FFAs (49.9 wt%), non-catalytic transesterification displayed a high BD yield (92.4 wt%; yields from catalytic transesterification: < 80.0 wt%). Moreover, blending the BD derived from the BSFL and FW residue extracts enhanced the fuel properties. The BSFL-assisted FW management efficiently reduced FW by 90 wt% while producing a high-quality BD.

Fe-doped TiO2 nanocrystals as highly efficient catalysts for heterogeneous catalytic transesterification of coconut oil

BackgroundThe impact of Fe doped TiO2 nanocatalyst on the heterogeneous catalytic transesterification reaction of coconut oil into biodiesel has been investigated. MethodsThe nanocatalyst was prepared by sol-gel method using titanium isopropoxide as TiO2 precursor and Fe(NO3)3 as iron (Fe) source. Several conditions of Fe-TiO2 were synthesized, each with Fe concentration of 0.5 %, 1 %, and 1.5 %, and calcined at 500 °C. The nanocatalyst's physical and chemical characteristics including phase crystallinity and morphology were examined. Significant findingsWe found that the biodiesel conversion efficiency increases with the increasing of Fe content in the Fe-TiO2 nanocatalyst and optimum at the Fe concentration of 1.5 % (w/w). The optimal Fe-TiO2 nanocatalyst could yield biodiesel output as high as 30.8 %, under at a relatively low temperature of 60 °C. Furthermore, the presence of the nanocatalyst effectively reduced the free fatty acid content in the biodiesel product by 1.43 %. Moreover, the acidity of the produced biodiesel was exceptionally low, at 0.02 %, primarily attributed to lauric acid. These exceptional performances are believed to be attributed to the enhanced surface chemistry properties of the Fe-TiO2 nanocatalyst. The Fe-TiO2 system is expected to find extensive application in the cost-effective production of biodiesel.

Lipase grafted on magnetic and CO2 dual-responsive Janus nanoparticles for interfacial catalyzed transesterification

Enzyme-loaded Pickering emulsions are a promising system for biphasic catalytic reactions. The monodisperse core-shell Janus nanoparticles (JNPs) P[xMAOAAO-yDEAEA]@RF@Fe3O4-CRL with magnetic and CO2 dual-responsiveness were synthesized by the wax/water emulsion. The catalysts can perfectly steady the oil/methanol Pickering emulsion and produce biodiesel by static transesterification of soybean oil. There is a synergistic effect between the interfacial activation of CRL realized by amphiphilic Janus supporters and the stability of the Pickering emulsions. Under optimal reaction conditions, the Pickering interfacial biocatalyst exhibits excellent enzymatic activity, reaching a biodiesel yield of 87.33 %. Furthermore, magnetic absorption and introduction of CO2 separate the catalyst P[2MAOAAO-DEAEA]@RF@Fe3O4-CRL from the system, and the biodiesel yield is 86.3 % after 6 cycles.

Micelle-modulated ribonuclease-like activities of oxo-bridged binuclear copper(ii) complexes with novel imidazole derivatives

Three bis-tridentate imidazole derivatives as ligands and their alkoxo-bridged binuclear copper(II) complexes (1, 2 and 3) were synthesized and characterized. Single crystals show that furan or thiophene moiety of 2 or 3 is free without a coordination with the central copper. Five-coordinated structure of 1 is constructed via two Cu-N and three Cu-O coordination bonds involving the participation of phenolic oxygen, alkoxo-bridged oxygen and the one carboxylate oxygen. Furthermore, catalytic reactivity of the as-synthesized binuclear complexes was evaluated for the transesterification of classic RNA model HPNP (2-hydroxypropyl-4-nitrophenyl phosphate). Overall, three complexes displayed the almost similar activity in both non-micellar and micellar solutions. HPNP transesterification achieved more obvious acceleration in micellar solutions of three kinds of cationic surfactants. All of three complexes obtained relatively good reactivity in CTAB micellar solution, respectively achieving approximately 804-fold (for 1), 762-fold (for 2) and 785-fold (for 3) rate enhancement compared to background rate of HPNP spontaneous cleavage. The as-synthesized binuclear complexes displayed approximately two times dominative activity in CTAB micellar solution over that in the non-micellar system. However, to some extent the introduction of amphoteric n-lauroylsarcosine sodium (LSS) and non-ionic polyoxyethylene lauryl ether (Brij35) inhibited the catalytic transesterification of HPNP. This study is beneficial to the design and application of novel mimic esterolases.

Artificial Neural Network and Response Surface Methodology for Predicting and Maximizing Biodiesel Production from Waste Oil with KI/CaO/Al2O3 Catalyst in a Fixed Bed Reactor.

Biodiesel from waste oil is produced using heterogeneous catalyzed transesterification in a fixed bed reactor (FBR). Potassium iodide/calcium oxide/alumina (KI/CaO/Al2O3) catalyst was prepared through the processes of calcination and impregnation. The novel catalyst was analyzed with X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometer (EDX). The design of experiment (DoE) method resulted in a total of 20 experimental runs. The significance of 3 reaction parameters, namely catalyst bed height, methanol to waste oil molar ratio, and residence time, and their combined impact on biodiesel yield is investigated. Both the artificial neural network (ANN) based on artificial intelligence (AI) and the Box-Behnken design (BBD) based on response surface methodology (RSM) were utilized in order to optimize the process conditions and maximize the biodiesel production. A quadratic regression model was developed to predict biodiesel yield, with a correlation coefficient (R) value of 0.9994 for ANN model and a coefficient of determination (R2) value of 0.9986 for BBD model. The maximum amount of biodiesel that can be produced is 98.88 % when catalyst bed height is 7.87 cm, molar ratio of methanol to waste oil is 17.47 : 1, and residence time is 3.12 h. The results of this study indicate that ANN and BBD models can effectively be used to optimize and synthesize the highest %yield of biodiesel in a FBR.

Microstructure and mechanical properties of a statistical aromatic-aliphatic copolyester synthesized by catalytic transesterification

Copolymerising polyethylene terephthalate (PET) and polycaprolactone (PCL) could provide a cost-effective method to recycle PET waste into a compostable plastic. In this work we investigated the relationship between formulation, microstructure, and mechanical properties during catalytic transesterification. It was found that the wt.% PCL was most effective in reducing the average PET block length and determining the copolymer's microstructure at equilibrium. Catalytic transesterification is a random process and can only give a narrow distribution when the average homopolymer block length is less than three, as determined by 1H NMR spectroscopy. A statistical copolymer marks reaction equilibrium where the average PCL block length is greater than one, contradicting the theoretical limit of a single PCL block length. It was proposed that the number of PCL ester groups available for reaction diminishes as transesterification progresses, leading to a favouring of the more abundant PET ester groups to undergo neutral or reverse reactions, resulting in equilibrium. As a result of the imbalance in the availability of PET and PCL ester groups at equilibrium, secondary factors, such as increasing the catalyst amount, were ineffective in further propagating transesterification. Copolymers formed in this study were either amorphous or semi-crystalline. The mechanical properties had minimal correlation with crystallinity and instead was mainly influenced by the ratio between the “hard” (PET) and “soft” (PCL and copolymer) segments in the microstructure and the molecular mass. In this study it was demonstrated that the microstructure of aromatic-aliphatic copolymers, synthesized through catalytic transesterification, can be manipulated to tailor physical properties to meet application requirements.

Extraction and Purification of Squalene from Virgin Olive Oil via Catalytic Transesterification and Molecular Distillation

Squalene, a highly valuable compound abundant in various natural sources, shows great potential in pharmaceutical, cosmetic, and nutraceutical applications. This research article outlines a comprehensive methodology for extracting and purifying squalene from virgin olive oil, a rich source of the compound. The extraction process begins with degumming, which involves heating the olive oil to 60-70°C to reduce viscosity, followed by the addition of 2-3% warm water to hydrate phospholipids. Food-grade phosphoric acid is then added to react with the phospholipids, forming precipitates. The mixture is stirred for 20-30 minutes and allowed to rest for an additional 20-30 minutes, enabling impurities to settle. The upper layer of degummed oil is separated via decantation or centrifugation and washed with warm water for pH adjustment. Next, transesterification is performed by mixing 100 ml of virgin olive oil with 25% methanol (w/w) and a catalyst (0.5% sodium methoxide or PTSA), and heating the mixture to 80-90°C under reflux for 1-2 hours. Following transesterification, the solvent and acetone are distilled out, and acetone precipitation is repeated 2-3 times to remove unsaponified matter, which is then filtered and evaporated. The concentrated oil undergoes molecular distillation at 180°C and 0.0033 bar pressure for 1 hour, yielding the distillate and residue for further analysis. Qualitative analysis using Thin Layer Chromatography (TLC) involves Merck TLC plates with silica gel 60 F254 and a hexane: chloroform (9:1) mobile phase. Spots are developed with a 10% HCl solution, confirming the presence of squalene with an RF value of 0.93. Quantitative analysis via High-Performance Thin-Layer Chromatography (HPTLC) employs Merck TLC plates with cyclohexane as the mobile phase and CAMAG at 254 nm and 366 nm wavelengths, revealing a squalene purity of 67% and a recovery rate of 69.8%. The initial purification through transesterification facilitated the conversion of ester groups, yielding squalene-rich fractions, while acetone precipitation effectively removed saponified matter. Molecular distillation further enhanced squalene purity. TLC analysis confirmed the qualitative presence of squalene, and HPTLC provided precise quantitative measurements. The obtained squalene purity of 67% significantly enriches the initial content in virgin olive oil, though further optimization could enhance purity and yield. Complementary techniques like GC-MS or HPLC could validate the purification process. This study presents an efficient, replicable procedure for extracting and purifying squalene from virgin olive oil, with significant implications for pharmaceutical, cosmetic, and nutraceutical industries. The findings support a sustainable and ethical shift towards vegetable-derived squalene, meeting market demands while ensuring high-quality production.

Transesterification of DMC with ethanol over K2CO3/Al2O3: The structure-performance relationship and catalytic mechanism

The transesterification of dimethyl carbonate (DMC) with ethanol to ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) has attracted increasing attention, which could be greatly promoted by heterogeneous solid base catalysts. The K2CO3/Al2O3 solid base catalysts with different active sites such as K2CO3, KAl(OH)2CO3, and KAlO2 were prepared for the transesterification reaction. The active sites of K2CO3 and KAl(OH)2CO3 mainly exist on the surface of KA-200 and KA-300, while K2CO3 and KAlO2 were mainly present on KA-400 and KA-500. The effects of active sites and the phase of support were studied systematically. KAl(OH)2CO3 showed higher activity than K2CO3 and KAlO2. In contrast, K2CO3 and KAlO2 displayed higher stability, with the activity of KA-400 kept stable over 2000 h. The excessive OH group of γ-AlOOH and water in the reaction system have a negative effect on the activity of the K2CO3/Al2O3 catalysts. The catalytic characterizations, transesterification reactions, and DFT calculations suggested that K+ in the KAl(OH)2CO3 species, with higher electron cloud density than that in K2CO3/γ-Al2O3, could efficiently promote the dissociation of ethanol and subsequent replacement of methoxy with ethoxy. The rate-determining step for the transesterification reaction was suggested to be the dissociation of ethanol.

Glycerol Carbonate Synthesis: Critical Analysis of Prospects and Challenges with Special Emphasis on Influencing Parameters for Catalytic Transesterification

Glycerol Carbonate Synthesis: Critical Analysis of Prospects and Challenges with Special Emphasis on Influencing Parameters for Catalytic Transesterification

Effective transesterification of castor oil to biodiesel catalyzed by novel carbon-based calcium composite

A novel carbon-based calcium catalyst was prepared through impregnation-calcination method, and was successfully applied as an effective catalyst for transesterification of castor oil to produce biodiesel. The catalyst prepared through the calcination at 500 °C for 3 h (Ca/C-500–3) exhibited the optimal performance. The prepared carbon-based calcium catalyst had excellent crystallinity and morphology, high basicity and surface area according to the characterization analysis results. Based on the XPS analysis, the combination of CaO and C in Ca/C-500–3 could improve the oxygen ion donating ability, which was beneficial for the reaction of triglycerides with methanol. The optimum composite of carbon-based calcium catalyst (Ca/C-500–3) displayed the excellent catalytic activity in castor oil transesterification, and 95.44 % of biodiesel conversion was obtained with the following conditions: methanol to oil molar ratio of 18:1, catalyst dosage of 5 wt%, reaction temperature of 65 °C and reaction time of 3 h. The TOF indicated that Ca/C-500–3 was an efficiency catalyst. Meanwhile, the calculation results of E-factor and PMI manifested that the transesterification of castor oil to biodiesel catalyzed by Ca/C-500–3 was a green reaction. Ca/C-500–3 could retain its high catalytic activity after five reaction cycles. The LCC cost analysis results suggested that, using Ca/C-500–3 as catalyst, biodiesel production from castor oil as feedstock had lower production cost compared to other biodiesel productions. The various factors affecting the cost of producing biodiesel were investigated using sensitivity analysis. Finally, the possible mechanism of catalytic transesterification reaction using carbon-based calcium composites was revealed.

Unveiling the innovation: Optimized biodiesel production from emerging Acer truncatum Bunge seed oil using novel and highly effective alkaline ionic liquid catalyst

Herein, three novel alkaline ionic liquids (ILs) with nitrogen-containing heterocycles were prepared via a two-step method, which were then utilized as excellent catalysts for biodiesel synthesis through transesterification of emerging Acer truncatum Bunge seed oil (ATBSO) and methanol. The alkaline ILs exhibited favorable catalytic performance, with 1-(2,3-dihydroxy)-propyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene) hydroxide ([DPTD][OH]) exhibiting the highest catalytic efficiency among them. Furthermore, the effect of the independent variables and their interactions on biodiesel yield were assessed and optimized using response surface methodology (RSM). Under the optimal parameters, which consisted of a reaction temperature of 71 °C, a reaction time of 137 min, a substrate molar ratio of methanol to ATBSO of 12:1, and a catalyst loading of 1.3 wt%, the biodiesel yield reached a maximum of 97.3 %. The catalytic transesterification of ATBSO for the preparation of biodiesel exhibited an activation energy (Ea), enthalpy (ΔH), entropy (ΔS) and the Gibbs free energy (ΔG) of 35.14 kJ·mol−1, 32.37 kJ·mol−1, −178.80 J·mol−1·K−1 and 93.70 kJ·mol−1 at 343 K, respectively. It is worth noting that, after the reaction, an automatic phase separation between biodiesel and the catalyst occurred, minimizing the processes of product isolation and purification. Additionally, [DPTD][OH] exhibited favorable reusability over the four reaction cycles, providing a sustainable and environmentally friendly approach for biodiesel production. The biodiesel obtained from ATBSO demonstrated excellent physicochemical properties, such as good cold flow property and flash point, which conform to the biodiesel standards outlined in ASTM D6751 and EN 14212.

The potential of biochar derived from banana peel/Fe3O4/ZIF-67@K2CO3 as magnetic nanocatalyst for biodiesel production from waste cooking oils

Using biomass-based catalysts in biodiesel production can make the process more economical and environmentally friendly. In this study, a new magnetic nanocatalyst was developed using banana peel biochar, ZIF-67, Fe3O4, and K2CO3, and then utilized in a catalytic transesterification process to convert waste cooking oils (WCO) into biodiesel. The level of free fatty acids of the treated WCO (WCOT) was reduced to generate a biodiesel with more suitable characteristics. The physicochemical aspects of the magnetic nanocatalyst were characterized by Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) and map techniques. In the transesterification process, the effect of temperature, methanol-to-oil ratio, process time, and nanocatalyst weight on the potential of nanocatalyst to produce biodiesel from WCO and WCOT was explored. The highest yield of biodiesel from WCO (96.82%) and WCOT (99.18%) was attained at 65 °C, nanocatalyst weight of 3 wt %, methanol-to-oil ratio of 19:1, a processing time of 3 h, and a mixing rate of 600 rpm. Based on thermodynamic studies, the biodiesel production process was endothermic and non-spontaneous. The regeneration of the nanocatalyst was studied using various solvents and n-hexane had a good ability to recover the catalyst (90% up to 5 stages). The results of the 1H NMR test revealed that the desired nanocatalyst had a high potential to generate biodiesel from WCO and WCOT. The properties of produced biodiesel met ASTM D6751 and EN 14214 standards.

Optimization and kinetic study of biodiesel production from Jatropha curcas oil in supercritical methanol environment using ZnO/γ-Al2O3 catalyst

AbstractIn this study, the conversion of crude Jatropha curcas oil into biodiesel through transesterification was investigated in the presence of heterogeneous solid catalysts under supercritical methanol environment. The principal impetuses catalyzing the expansion in optimal biodiesel production are primarily attributed to the increasing demand for sustainable energy sources, the availability of raw materials, and innovations in production methodologies. To maintain the optimization, 6 wt% and 10 wt% of zinc oxide (ZnO) were incorporated into gamma-alumina (γ-Al2O3) through a wet impregnation method followed by calcination at 900 °C. Furthermore, the study examined the effect of alcohol/oil molar ratio, reaction temperature, and reaction time on the process to achieve maximum biodiesel production. The study revealed that a catalyst consisting of 10 wt% ZnO on γ-Al2O3 exhibited exceptional performance with a biodiesel yield of 95.64% under the reaction conditions of a molar ratio of 1:40 oil to methanol, a temperature of 300 °C, a pressure of 9 MPa, and a residence time of 3 min compared to the yield of 100% under same condition at residence time of 9 min. After thorough investigation, the kinetics of the catalytic transesterification reaction were elucidated, and suitable kinetic parameters were proposed.

Rational biodiesel production from oxidation stability perspective: Evaluation of lipid-soluble carbonyl compound formation in the seed oil and biodiesel with long-term storage

The exploration of appropriate feedstock and catalytic transesterification hinders the practical application of biodiesel. Here, we introduced rational biodiesel production from oxidation stability perspective and evaluated the lipid-soluble carbonyl-containing oxidation products in long-term stored biodiesel samples that prepared from different oil source, catalyst for production, and ester bond type. A stable isotope labeling method based on liquid chromatography-high resolution-mass spectrometry (SIL-LC-HRMS) detection is established using a pair of labeling reagents namely1-(2-hydrazinyl-2-oxoethyl)pyridin-1-ium chloride (GP) and [2H5]1-(2-Hydrazinyl-2-oxoethyl)pyridin-1-ium chloride ([2H5]GP) for lipid-soluble carbonyl-containing oxidation products, including aldehydes and ketones. The main benefits of SIL-LC-HRMS are its sensitivity, selectivity, and feature coverage towards carbonyl-containing compounds and realized their non-targeted screening and relative quantification from complex matrices. Using SIL-LC-HRMS analysis, it was estimated the distribution and formation of 131 carbonyl compounds in three different kinds of second-generation feedstock and biodiesels with one-year storage in the dark. Double bond equivalent (DBE)-number of carbon (nC) plots and hierarchical clustering heatmap analysis reveal the effect of the oil source, catalyst type, and alkyl ester bond type on the variance in carbonyl compound formation during long-term biodiesel storage, arguably the most crucial factor oxidation stability in rational biodiesel production. The carbonyl formation and their variations in biodiesel samples are also discussed by theoretically calculating the bond dissociation energy for the primary constituent of seed oil and biodiesel.

Methyl ester production from cotton seed oil via catalytic transesterification process; characterization, fatty acids composition, kinetics, and thermodynamics study

In this study, Cotton seed methyl ester (CSME) was produced from extracted Cotton seed oil (CSO) through transesterification process that involves two steps. The CSO obtained from solvent extraction was first esterified using an acid catalyst to obtain the FAME, which was then used in the based catalysed transesterification process that produced the CSME. The physicochemical properties and fatty acids composition of the extracted CSO and produced CSME were evaluated according to the ASTM approved standards. Also, the percentage conversion, activated energy, kinetics, and thermodynamics of the transesterification process were studied. The results also indicate that increase in time and temperature has a positive effect on the percentage conversion of CSO to CSME. The highest percentage conversion (95.48%) was achieved at 65 °C and 150 min. The reaction rate constants obtained for the irreversible pseudo first and second order models were within the range of 4.59 × 10−2 min−1 to 6.77 × 10−2 min−1 and 9.50 × 10−2 dm3mol−1min−1 to 2.27 × 10−1 dm3mol−1min−1, respectively. However, the R2 values indicate that the CSO transesterification reaction was best described by the irreversible pseudo second order model. The activation energy obtained was 18.98 kJ/mol and 43.17 kJ/mol for the pseudo first and second order models, respectively. ∆H, ∆S, and ∆G values for irreversible pseudo first and second orders models, are 13.89 KJ/mol, − 0.158 KJ/mol, and 20.43 – 23.56 KJ/mol and 35.92 KJ/mol, − 0.165 KJ/mol, and 85.21 – 88.31 KJ/mol, respectively. The cetane number, kinematic viscosity, calorific value, flash point, and acid value obtained for the CSME were 53.1, 4.81 mm2/s, 43,690 kJ/kg, 154 ℃, and 0.1 mg KOH/g oil, respectively. The CSME produced has physicochemical properties comparable to those of petroleum-derived diesel.