Esterification Of Lactic Acid Research Articles

Enhanced upgrading of lignocellulosic substrates by coculture of Saccharomyces cerevisiae and Acinetobacter baylyi ADP1

BackgroundLignocellulosic biomass as feedstock has a huge potential for biochemical production. Still, efficient utilization of hydrolysates derived from lignocellulose is challenged by their complex and heterogeneous composition and the presence of inhibitory compounds, such as furan aldehydes. Using microbial consortia where two specialized microbes complement each other could serve as a potential approach to improve the efficiency of lignocellulosic biomass upgrading.ResultsThis study describes the simultaneous inhibitor detoxification and production of lactic acid and wax esters from a synthetic lignocellulosic hydrolysate by a defined coculture of engineered Saccharomyces cerevisiae and Acinetobacter baylyi ADP1. A. baylyi ADP1 showed efficient bioconversion of furan aldehydes present in the hydrolysate, namely furfural and 5-hydroxymethylfurfural, and did not compete for substrates with S. cerevisiae, highlighting its potential as a coculture partner. Furthermore, the remaining carbon sources and byproducts of S. cerevisiae were directed to wax ester production by A. baylyi ADP1. The lactic acid productivity of S. cerevisiae was improved approximately 1.5-fold (to 0.41 ± 0.08 g/L/h) in the coculture with A. baylyi ADP1, compared to a monoculture of S. cerevisiae.ConclusionThe coculture of yeast and bacterium was shown to improve the consumption of lignocellulosic substrates and the productivity of lactic acid from a synthetic lignocellulosic hydrolysate. The high detoxification capacity and the ability to produce high-value products by A. baylyi ADP1 demonstrates the strain to be a potential candidate for coculture to increase production efficiency and economics of S. cerevisiae fermentations.

Synthesis, characterization and performance evaluation of a nontoxic functional plasticizer for poly(vinyl chloride) derived from sustainable lactic acid

The use of plasticizers is crucial in enhancing the flexibility of engineering plastics. Currently, the primary plasticizers employed in poly(vinyl chloride) materials are nonrenewable phthalates. These exhibit a detrimental impact on the environment and human health owing to their toxic benzene ring structure. Consequently, the development of easily synthesizable, green plasticizers with excellent properties using biobased resources has been a long-standing objective in the field of resin plasticizing. Herein, we synthesized a branched lactic acid ester (BLAE) plasticizer using esterification and acid anhydride end-capping methods. Further, we investigated its application performance and oral toxicity. The abundance of polar ester groups in the oligolactic acid structure enables them to form secondary bonds with polymer chains. This results in a glass transition temperature is 59% less than that of pure poly(vinyl chloride), thereby improving the mechanical properties of the material. The addition of the BLAE plasticizer not only improved the thermal stability of the compound film but also effectively reduced the self-catalytic dehydrochlorination reaction of poly(vinyl chloride). This overcomes the limitations of unmodified poly(vinyl chloride), such as performance deterioration and color variation due to light exposure. Furthermore, the hydrophobicity of the compound film was substantially enhanced, resulting in outstanding antifouling and self-cleaning properties. These findings suggest that lactic acid-based plasticizer exhibits comparable or even superior overall performance when compared to commercially available plasticizers such as dioctyl phthalate and acetyl tributyl citrate. This work not only addresses the gap in the toxicity assessment of lactic acid plasticizers but also demonstrates their nontoxic characteristics in acute oral toxicity tests. This research offers novel insights into the green synthesis and functional development of biobased plasticizers, showcasing considerable potential for the substituting of dioctyl phthalate.

Development of lactic acid based chain extender and soybean oil-derived polyurethanes for ecofriendly sustained drug delivery systems

In the present study, a range of sustainable, biocompatible and biodegradable polyurethanes (PU-1 to PU-4) were synthesized using different combinations of biobased polyol (obtained through the epoxidation of soybean oil, followed by ring opening with ethanol) and polyethylene glycol (PEG) and isophorone diisocyanate. The sustainable chain extender used in this study was synthesized by the esterification of lactic acid with ethylene glycol (EG). The synthesized PU samples were characterized through scanning electron microscopy (SEM), Fourier transformed infrared (FTIR) and nuclear magnetic resonance (1H NMR and 13C NMR) spectroscopy. Wetting ability and thermal degradation analysis (TGA) of the samples were also studied. Subsequently, these PUs were examined as potential drug delivery systems using Gabapentin as a model drug, which was loaded in the polymer matrix using the solvent evaporation method. The drug release studies were carried out in 0.06 N HCl as a release medium according to the method outlined in the United States Pharmacopeia. The maximum drug release was observed for sample PU-P1, which was found to be 53.0 % after 6 h. Moreover, a comparison of different PU samples revealed a trend wherein the values of drug release were decreased with an increase in the PEG content.

Effect of stearic and oleic acid-based lipophilic emulsifiers on the crystallization of the fat blend and the stability of whipped cream.

Effect of stearic acid-based lipophilic emulsifiers (sorbitan monostearate (Span-60), sucrose ester S-170, and lactic acid esters of monoglycerides (LACTEM)) and oleic acid-based lipophilic emulsifiers (sorbitan monooleate (Span-80) and sucrose ester O-170) on the crystallization of fat blend and the stability of whipped cream were studied. Span-60 and S-170 possessed strong nucleation inducing ability and good emulsifying properties. Thus, tiny and uniform crystals were formed in fat blends, small and ordered fat globules were distributed in emulsions, and air bubbles were effectively wrapped in firmly foam structures. The crystallization of the fat blend and the stability of whipped cream were slightly modified by LACTEM due to its poor nucleation inducing ability and moderate emulsifying characteristic. Span-80 and O-170 had weak nucleation inducing ability and poor emulsifying properties, therefore, loose crystals were formed in fat blends and some big fat globules were separated in emulsions, thereby decreasing the stability of whipped creams.

Unravelling the potential of non-conventional yeasts and recycled brewers spent grains (BSG) for non-alcoholic and low alcohol beer (NABLAB)

The non-alcoholic beer sector has seen steady growth in recent years and non-conventional yeasts could be a chance to produce this specialty beer. On the other hand, non-alcoholic beer with appreciated aromatic characteristics remains a challenge. In this work, 14 yeast strains belonging to 7 different species were tested to produce low-alcohol or alcohol-free beers using recycled low-sugar wort from brewers spent grains (BSG). The results showed that a strain of Lachancea thermotolerans and a strain of Torulaspora delbrueckii exhibited a fermentation evolution comparable to that of Saccharomyces cerevisiae commercial strain with a reduced ethanol (0.46, 0.57, 1.22 % v/v respectively). L. thermotolerans strains were characterized by lactic acid production and esters formation with the strain DiSVA 322 that exhibited the best aromatic and sensorial performance. T. delbrueckii DiSVA 253 showed an effective analytical profile with a peculiar sensory profile. Although Pichia kluyveri strains did not show significant fermentation evolution, the strains DiSVA 1078 and DiSVA 1079 revealed positive sensorial and analytical traits that significantly distinguished the beers for fruity/esters and sweet notes. The wort from recycled BSG resulted a favourable substrate to produce of non-alcoholic or low alcoholic beers in conjunction with selected non-conventional yeasts.

A facile route for concurrent fabrication and surface selective functionalization of cellulose nanofibers by lactic acid mediated catalysis

Celulose nanofibers are lightweight, recycable, biodegradable, and renewable. Hence, there is a great interest of using them instead of fossil-based components in new materials and biocomposites. In this study, we disclose an environmentally benign (green) one-step reaction approach to fabricate lactic acid ester functionalized cellulose nanofibrils from wood-derived pulp fibers in high yields. This was accomplished by converting wood-derived pulp fibers to nanofibrillated “cellulose lactate” under mild conditions using lactic acid as both the reaction media and catalyst. Thus, in parallel to the cellulose nanofibril production, concurrent lactic acid-catalyzed esterification of lactic acid to the cellulose nanofibers surface occured. The direct lactic acid esterification, which is a surface selective functionalization and reversible (de-attaching the ester groups by cleavage of the ester bonds), of the cellulose nanofibrils was confirmed by low numbers of degree of substitution, and FT-IR analyses. Thus, autocatalytic esterification and cellulose hydrolysis occurred without the need of metal based or a harsh mineral acid catalysts, which has disadvantages such as acid corrosiveness and high recovery cost of acid. Moreover, adding a mineral acid as a co-catalyst significantly decreased the yield of the nanocellulose. The lactic acid media is successfully recycled in multiple reaction cycles producing the corresponding nanocellulose fibers in high yields. The disclosed green cellulose nanofibril production route is industrial relevant and gives direct access to nanocellulose for use in variety of applications such as sustainable filaments, composites, packaging and strengthening of recycled fibers.

Tungsten trioxide-modified zeolite-based catalysts in the esterification of lactic acid: the effect of Si/Al ratio and WO3 loadings

Tungsten trioxide-modified zeolite-based catalysts in the esterification of lactic acid: the effect of Si/Al ratio and WO3 loadings

Poly(lactic acid)/Plasticizer/Nano-Silica Ternary Systems: Properties Evolution and Effects on Degradation Rate

Plasticized nanocomposites based on poly(lactic acid) have been prepared by melt mixing following a two-step approach, adding two different oligomeric esters of lactic acid (OLAs) as plasticizers and fumed silica nanoparticles. The nanocomposites maintained a remarkable elongation at break in the presence of the nanoparticles, with no strong effects on modulus and strength. Measuring thermo-mechanical properties as a function of aging time revealed a progressive deterioration of properties, with the buildup of phase separation, related to the nature of the plasticizer. Materials containing hydroxyl-terminated OLA showed a higher stability of properties upon aging. On the contrary, a synergistic effect of the acid-terminated plasticizer and silica nanoparticles was pointed out, inducing an accelerated hydrolytic degradation of PLA: materials at high silica content exhibited a marked brittleness and a dramatic decrease of molecular weight after 16 weeks of aging.

Determination of E 472b emulsifiers in foamed food formulations by high-performance thin-layer chromatography‒fluorescence detection

E 472b emulsifiers, defined as lactic acid esters of mono- and diacylglycerides, are food emulsifiers widely used in foamed food formulations. So far, only qualitative methods for analyzing E 472b emulsifiers have been published. Thus, a new method was developed for determining E 472b in different foamed food formulations by high-performance thin-layer chromatography with fluorescence detection (HPTLC‒FLD). The proposed method allows simple and fast E 472b emulsifier extraction from the food matrix and points out an analytical approach for quantifying these emulsifiers using a commercial E 472b emulsifier as the reference standard. Limits of decision with 56‒59 ng of E 472b emulsifier/zone and limits of quantification with 172‒179 ng of E 472b emulsifier/zone in three foamed model food formulations, respectively, as well as satisfactory repeatability (n = 6) and reproducibility (n = 6) exposed by low relative standard deviation < 8% proved the method suitable for the sensitive and reliable determination of E 472b emulsifiers. Recoveries between 96 and 109.3% were obtained for all investigated model systems. In commercial foamed food formulations from the German market, the E 472b emulsifier content ranged between 0.1 and 0.6 g/100 g.

Lactic acid esterification of maize starch in solid state: Assistant effect of pullulanase modification on digestibility and physicochemical properties

The current work was the first report to prepare lactate-esterified debranched starch (LEDS) in solid state mode. Normal maize starch (NS) was initially modified by pullulanase enzyme in granule form and then esterified with lactic acid under dry heating for 3 h at 80 °C and presence of 0.2% w/w sodium hydroxide. Physicochemical properties of the treated starches by single and dual treatments were determined and compared with NS. The enzymatic modification could improve reaction efficiency of esterification process up to 75.2% through partial hydrolysis of starch chains. Compared with NS and individual modifications, the combined treatment significantly increased amylose extent, and the amount of resistant starch (RS) while decreased the freeze thaw stability, viscosity, gelatinization temperatures, paste clarity, swelling power, and relative crystallinity. The morphological examination showed dissociation and degradation of starch granules by single and dual treatments. FT-IR confirmed the introduction of ester groups onto the starch molecules through a band at 1715 cm−1. The impact of designed dual treatment on the environment was assessed by applying Eco-scale index, proving the greenness of the method (score: 75). The findings of this study will provide a theoretical background for development of high RS food products.

High-Pressure Depolymerization of Poly(lactic acid) (PLA) and Poly(3-hydroxybutyrate) (PHB) Using Bio-Based Solvents: A Way to Produce Alkyl Esters Which Can Be Modified to Polymerizable Monomers.

The polyesters poly(lactic acid) (PLA) and poly(3-hydroxybutyrate) (PHB) used in various applications such as food packaging or 3D printing were depolymerized by biobased aliphatic alcohols-methanol and ethanol with the presence of para-toluenesulphonic acid (p-TSA) as a catalyst at a temperature of 151 °C. It was found that the fastest depolymerization is reached using methanol as anucleophile for the reaction with PLA, resulting in the value of reaction rate constant (k) of 0.0425 min-1 and the yield of methyl lactate of 93.8% after 120 min. On the other hand, the value of constant k for the depolymerization of PHB in the presence of ethanol reached 0.0064 min-1 and the yield of ethyl 3-hydroxybutyrate was of 76.0% after 240 min. A kinetics study of depolymerization was performed via LC-MS analysis of alkyl esters of lactic acid and 3-hydroxybutanoic acid. The structure confirmation of the products was performed via FT-IR, MS, 1H NMR, and 13C NMR. Synthesized alkyl lactates and 3-hydroxybutyrates were modified into polymerizable molecules using methacrylic anhydride as a reactant and potassium 2-ethylhexanoate as a catalyst at a temperature of 80 °C. All alkyl esters were methacrylated for 24 h, guaranteeing the quantitative yield (which in all cases reached values equal to or of more than 98%). The methacrylation rate constants (k') were calculated to compare the reaction kinetics of each alkyl ester. It was found that lactates reach afaster rate of reaction than 3-hydroxybutyrates. The value of k' for themethacrylated methyl lactate reached 0.0885 dm3/(mol·min). Opposite to this result, methacrylated ethyl 3-hydroxybutyrate's constant k' was 0.0075 dm3/(mol·min). The reaction rate study was conducted by the GC-FID method and the structures were confirmed via FT-IR, MS, 1H NMR, and 13C NMR.

Production of ethyl lactate by reactive dividing wall column using analysis of the statics

The sustainable development in separation-reaction processes involves a higher energy efficiency and pollutant reduction. The main interest of the analysis of the statics methodology is developed the optimal qualitative technological scheme with minimal data, the physicochemical information of the system, and the stoichiometry of the reaction. This results in a feasible intensified scheme flowsheet and a reactive distillation column (RD) that are then implemented in a reactive dividing wall column (RDWC) distillation to produce ethyl lactate from the esterification of lactic acid with ethanol. The RDWC configuration showed a reduction of 38% in the save net duty and an increase of 13% in the conversion compared with a conventional direct sequence. The analysis of the statics method presents an alternative in the design stage in a complex column, allowing for a feasible operation in different degrees of process intensification.

Density and Viscosity of Glycolic, Lactic, and Malic Acid Esters

Densities and viscosities were measured as a function of temperature for 12 esters of glycolic, dl-lactic, and dl-malic acids and linear chain alcohols C1–C5. The density and kinematic viscosity were obtained using a pycnometer and a Pinkevitch capillary viscometer in a temperature range of 293.15–363.15 K with accuracies of 0.1 and 0.35%, respectively. The obtained data were used for dynamic viscosity calculation. It was demonstrated that the viscosity–temperature dependence of esters was described by the ASTM D341 model with an average absolute relative deviation of 1%. The temperature dependence of dynamic viscosity was fitted using the Arrhenius-like equation and Vogel–Fulcher–Tammann (VFT) model. It was found that the adjustable parameters A and B have the similar value for compounds in one homologous series. These parameters were taken as constant for each series of esters of the corresponding acids. The dynamic viscosity–temperature dependence of esters was better described by the VFT model than the Arrhenius-like equation. The capabilities of some group-additivity methods for predicting density have been reviewed and compared with experimental results.

Recent advances in the utilization of glycerol for the production of lactic acid by catalysis

AbstractIn this review, the research progress on catalytic conversion of glycerol to lactic acid or lactate esters and the reaction mechanisms with different catalysis systems are summarized. Both homogeneous catalysts, including inorganic bases and metal complexes, and heterogeneous catalysts, including metal oxides, molecular sieves, polyoxometalates and noble and non‐noble metals, are discussed. In particular, the influence of catalyst components, the physical and chemical properties of the catalysts and additives and solvents on the catalytic performances are highlighted. In comparison, nano‐metal particles or bimetal catalysts could achieve good catalytic performance, in which the alloy and synergistic effects might form under certain conditions. For further improvement of the sustainable transformation of glycerol to lactic acid or lactate esters, attention should still be paid to rational design of novel cost‐effective, high‐efficiency and green catalytic systems. © 2022 Society of Chemical Industry and John Wiley &amp; Sons, Ltd.

Effects of modernized fermentation on the microbial community succession and ethyl lactate metabolism in Chinese baijiu fermentation

Modernized mechanization and intelligent transformation are the trends of Chinese baijiu industry development. However, these changes affect the operational environment, which lead to the decreased metabolism of esters during baijiu fermentation, especially for ethyl lactate. Ethyl lactate is an important flavor compound in most types of baijiu, which is mainly produced by esterification of lactic acid and ethanol. However, considerably less is known about the dynamic microbial succession related to ethyl lactate metabolism during the modernized baijiu fermentation process. In this study, we investigated the lactic acid bacteria, yeast and mold community succession and ethyl lactate metabolism during baijiu fermentation. Results showed that fermentation mode had a significant effect on lactic acid and ethyl lactate metabolism (p < 0.001). Specifically, the accumulation of lactic acid in modernized process was 50% lower than that in traditional process (23.22 ± 7.41 g/kg versus 33.92 ± 2.32 g/kg fermented grains). The accumulation of ethyl lactate in the modernized baijiu fermentation process (9.46 ± 1.78 g/kg fermented grains) was significantly lower than that in traditional baijiu fermentation process (37.10 ± 5.86 g/kg fermented grains). Moreover, Illumina Miseq sequencing showed 11 lactic acid bacteria OTUs, 6 yeast OTUs and 4 mold OTUs were abundant during fermentation. Compared with traditional baijiu fermentation process, modernized process led to more Lactobacillus and Candida, but less Pichia, Aspergillus, Rhizomucor and Rhizopus during fermentation. Based on the redundancy analysis and correlation network analysis, our study showed the metabolism of ethyl lactate mainly related to the activities of Pichia, Aspergillus, Rhizomucor and Rhizopus, especially for Rhizomucor and Rhizopus. This study revealed that the regulation of Pichia, Aspergillus, Rhizomucor Rhizopus and Candida might be an effective orientation for adjusting the metabolism of ethyl lactate during modernized baijiu fermentation.

Low-Temperature Hydrophilic Pervaporation of Lactic Acid Esterification Reaction Media.

Esterification reactions show a limited conversion due to the presence of water, which favors the opposite reaction. The removal of water from the reaction mixture increases the production of the ester. Pervaporation is an effective dehydration technique, usually applied to binary mixtures. The effect on pervaporation of a reactive multicomponent system involving water, ethanol, ethyl lactate and lactic acid with high acid concentration (13.5 wt. %) at relatively low temperatures (40–80 °C) was studied. Three hydrophilic membranes mainly fabricated for dehydration purposes from Sulzer Chemtech were used, i.e., PERVAP™ 3100, PERVAP™ 2216 and PERVAP™ 1131. The last one revealed as the most suitable for the application and it was further characterized with binary and ternary solutions. The membrane showed high affinity for the lactic acid. The acid permeation played a key role in the water/ethanol and water/ethyl lactate selectivity. Lactic acid permeates and crystalizes in the permeate side of the membrane at very low water concentration (below 2 wt. %), causing a drop in flux and membrane selectivity. Ethyl lactate is responsible of the loss of integrity of the membranes.

Ethyl lactate production by reactive distillation - optimization of reaction kinetics and energy efficiency.

Background: Ethyl lactate is an environmentally benign solvent, which could substitute petrol-based volatile organic compounds (VOCs) in many applications if production costs are reduced. It is usually produced by the esterification of lactic acid with ethanol - two important chemical building blocks of biorefineries that are available at industrial scale. Reactive distillation is a promising alternative production process, which utilises process intensification to increase energy efficiency and space-time yield by enhancing the reaction kinetics. Methods: In this work, process intensification of ethyl lactate production by means of distillation was analysed with special focus on the efficient separation of water.Different setups were evaluated. The feedstock requirements were studied and the process was optimized regarding reaction kinetics in experiments on laboratory level. The preparation of anhydrous starting mixtures for ethyl lactate formation was tested in batch experiments and applied to reactive distillation. The simultaneous distillation was optimized and assessed for its energy efficiency. For this purpose, integrated reactive distillation was compared to a simple setup for distillation enhanced esterification. Results: It was found that an optimized serial setup of reactors and distillation steps can offer similar process intensification at a lower distillate rate compared to simultaneous reactive distillation and is therefore more energy efficient. Moreover, the serial setup is more flexible and straight-forward to regulate and scale-up. Conclusions: Based on the experimental results, the optimal setup and parameters of a continuous process for ethyl lactate production by distillation enhanced esterification was presented.

Plasmonic silver nanoparticles decorated surface functionalized Zirconium doped quantum dots - for enhanced photochemical synthesis of lactic acid esters

Lactic acid, or 2-hydroxypropionic acid (CAS 50-21-5), a natural organic acid immensely engaged in agricultural industry, pharmacy, garment and chemical industry with a long history of practice. Lactic acid generated in fermentation necessitates an extra purification step that must be cost-effective. A green and energy derivatization of lactic acid into corresponding esters was carried out under photocatalytic conditions in this study to render them volatile for distillation separation. Esterification reaction was carried out under low energy photocatalytic system under solvent free conditions using a range of Zirconium impregnated-activated Titanium dioxide photocatalysts (1-0.005Ag/1.9-4.4%S-2.5-12.5%Zr@TO). Both physical and chemical events in the reaction grid have been studied and thermodynamic and kinetic parameters have been established expending pseudo-homogeneous (PH), Eley-Rideal (ER) and Langmuir-Hinshelwood-Haugen-Watson (LHHW) models and the different adsorption of components were proposed to fit the intrinsic kinetic data. Reaction mechanism for the process have been proposed based on the kinetic modelling results as well as FT-IR, TGA, Ammonia-TPD and photo-Electrochemical characterizations, as well as radical trapping tests, were also used to effectively support the reaction mechanism. The findings will be beneficial in the design of industrial photo-reactors for low temperature ester synthesis strategies.

Influence of Lactic Acid Surface Modification of Cellulose Nanofibrils on the Properties of Cellulose Nanofibril Films and Cellulose Nanofibril-Poly(lactic acid) Composites.

In this study, cellulose nanofibrils (CNFs) were modified by catalyzed lactic acid esterification in an aqueous medium with SnCl2 as a catalyst. Films were made from unmodified and lactic acid-modified CNF without a polymer matrix to evaluate the effectiveness of the modification. Ungrafted and lactic acid-grafted CNF was also compounded with poly(lactic acid) (PLA) to produce composites. Mechanical, water absorption, and barrier properties were evaluated for ungrafted CNF, lactic acid-grafted CNF films, and PLA/CNF composites to ascertain the effect of lactic acid modification on the properties of the films and nanocomposites. FTIR spectra of the modified CNF revealed the presence of carbonyl peaks at 1720 cm−1, suggesting that the esterification reaction was successful. Modification of CNF with LA improved the tensile modulus of the produced films but the tensile strength and elongation decreased. Additionally, films made from modified CNF had lower water absorption, as well as water vapor and oxygen permeability, relative to their counterparts with unmodified CNFs. The mechanical properties of PLA/CNF composites made from lactic acid-grafted CNFs did not significantly change with respect to the ungrafted CNF. However, the addition of lactic acid-grafted CNF to PLA improved the water vapor permeability relative to composites containing ungrafted CNF. Therefore, the esterification of CNFs in an aqueous medium may provide an environmentally benign way of modifying the surface chemistry of CNFs to improve the barrier properties of CNF films and PLA/CNF composites.

Synthesis and characterization of bio catalyst prepared from dairy waste for lactic acid esterification

Abstract Dairy byproduct is known for its valuable chemical and nutritional content possessing high market potential. Notwithstanding, it is tractable to exploit its utilization. The waste generated is organic and having huge energy potential. The objective of current research is to synthesize novel catalyst from a dairy based solid waste called Ghee Residue by chemical activation process and deploy it for the production of iso-butyl lactate. Surface identity of catalyst was furnished using Brunauer-Emmet Teller (BET) method and Fourier Transform Infrared Spectroscopy (FTIR). Effect of variables like reaction time, temperature of reaction and loading of catalyst on lactic acid conversion were studied. In addition to this, reaction kinetics modelling was performed using 2nd order pseudo-homogeneous approach. It was inferred that, both internal as well as external resistance of mass transfer could not offer any influence on overall rate of reaction in this esterification. Optimum condition for esterification reaction was at 368 K with 3% catalyst loading giving the highest conversion around 74%. The energy of activation for the present system using synthesized catalyst was 41.5 kJ/mol and found to be lower in comparison with the other catalysts. Although, the activity of GRC declined gradually less than 10% from the activity of the several reaction cycle.