Fatty Acid Methyl Esters Research Articles

Fischer-Speier Esterification and Beyond: Recent Mechanicistic Advances

Over the past 130 years, Fischer-Speier esterification has been established as the benchmark method for synthesizing esters from organic acids and alcohols. The reaction’s versatility, arising from the vast combinations of starting materials and the numerous catalytic alternatives to the traditional H2SO4, has maintained its relevance, with a steady flow of publications addressing new developments. This review highlights the most significant contributions to Fischer-Speier esterification over the past five years, with a particular emphasis on mechanistic advancements and innovative catalytic systems. Both homogeneous and heterogeneous catalytic approaches are discussed, including novel catalysts leveraging hydrogen-bonding interactions and systems offering fresh insights into specific reaction mechanisms and atypical methodologies. Some of these catalytic systems, as ionic liquids or sulfonated heterogeneous catalytic precursors, reached excellent yields (>90%), e.g., in the synthesis of fatty acids methyl esters. Also, classic catalysts such as H2SO4 and para-toluen sulfonic acid were optimized for quantitative conversions (e.g., in the esterification of trans-cinnamic acid with methanol). A consistent number of catalysts was studied with model substrates (as benzoic acid in combination with methanol, ethanol, and ethylene glycol), and new activation pathways were presented.

Enhanced catalytic performance of methanol-tolerant Rhizopus stolonifera immobilized on polyurethane foam with hydrophobic coating for biodiesel production

The limited methanol tolerance and glycerol adsorption tendency of whole-cell catalysts are the main factors contributing to the extended catalytic cycle and limited catalyst reusability in biodiesel preparation. In this study, a 7.5 % methanol-tolerant Rhizopus stolonifera mutant (MTS2) was developed through the atmospheric and room temperature plasma (ARTP), exhibiting a 1.5-fold increase in methanol tolerance compared with the wild type strain (WT-RS), along with a 93.5 % increase in lipases activity. Polyurethane foam PF3 with an average pore size of 0.15 mm and 90 A rigidity is optimal for MTS2 immobilization (MTS2 @PF3), enabling its application in continuous processing for industrial applications. Utilizing soybean oil as a substrate, the catalyst MTS2 @PF3 produced 95.5 % of fatty acid methyl esters (FAME) in 36 hours under optimal conditions (30°C, 180 r/min, catalyst dosage of 15 % g/g oil, 30 % water content, and methanol addition in Scheme 3), achieving over a 50 % reduction in reaction time compared with WT-RS@PF3. To address limitations in catalyst reusability due to glycerol adsorption, various modifiers, including rosin-based modifier (RM), amino silicone oil (ASO), graphene (GRA), betaine and Tween 80 were evaluated. The glycerol adsorption rates experienced substantial reductions (39.3 % with RM and 85.6 % with betaine), and the catalysts maintained above 60 % FAME yield even after 8 reaction cycles. The combination of enhanced methanol tolerance, lipase activity, and reduced glycerol adsorption contribute to enhanced catalytic efficiency and reusability, which can reduce production costs for biodiesel manufacturing. The composite of these attributes makes MTS2 @RM1-PF3 and Betaine-MTS2 @PF3 as promising candidate for industrial biodiesel production, addressing previous limitations in catalyst performance and sustainability. The developed immobilized whole-cell catalysts exhibit promising potential for more sustainable and cost-effective processes in biodiesel manufacturing.

Surfactant-modified ZnFe2O4/CaOPS porous acid-base bifunctional catalysts for biodiesel production from waste cooking oil and process optimization

Biodiesel production from waste cooking oil (WCO) with high acid value is useful for clean energy development and utilization. In this work, ZnFe2O4(5)/CaOPS porous bifunctional catalysts were prepared for catalytic production of biodiesel with the help of surfactants such as PVP, SDS and citric acid, using a sol-gel method. The ZnFe2O4(5)/CaOPS catalysts were characterized using XRD, SEM, EDX, NH3-TPD, and BET. The parameters (reaction temperature, catalyst dosage, methanol-oil ratio and reaction time) for the transesterification reaction to produce fatty acid methyl esters (FAMEs) were optimized for the optimal materials using a one-variable method. Experiments were designed using Response Surface Methodology (RSM) and Artificial Neural Network (ANN) for global optimization to obtain the best process parameters. The final average yield of FAMEs was 96.89% under the optimum reaction parameter of catalyst dosage of 5.06wt%, reaction temperature of 63.69°C, reaction time of 212.22min and methanol-oil ratio of 12.96:1. The prepared biodiesel was characterized using FT-IR, 1H NMR as well as 13C NMR and compared with international standard ASTM D6751. The ZnFe2O4(5)/CaOPS catalyst has excellent stability in biodiesel production and has some free fatty acid tolerance. In addition, a cost analysis and sensitivity analysis were done for the production of WCO biodiesel. It is hoped that the research results in this paper can provide a theoretical basis for biodiesel production from WCO with high free fatty acid content.

Heterogeneization of Biodiesel Production by Simultaneous Esterification and Transesterification of Oleins

The production of biodiesel via simultaneous esterification and transesterification reactions of residual fats such as palm oleins, with variable TG and FFA composition, using methanol and methane sulfonic acid (MSA) or an acid carbon-based structured catalyst (SO3H-C) as homogeneous and heterogeneous catalysts respectively, has been investigated. The influence of various parameters, such as methanol to oil molar ratio, operating temperature, amount of catalyst, or nature and composition of the raw materials on the fatty acid methyl esters (FAME) yield was studied. It was determined that increasing the methanol to oil molar ratio resulted in an increase in the conversion of TG and FFA and a higher FAME yield; besides, reaction temperature has a strong effect. The best conditions tested to obtain the highest FAME yield (99.2%) was a methanol to oil molar ratio of 12:1, 120 °C (12 bar), a reaction time of at least 1 h, and 3% MSA as a homogeneous catalyst. The work demonstrated that an acidic solid catalyst, SO3H-C, homemade prepared, could be used as a heterogeneous catalyst in the simultaneous process under the optimized reaction conditions, achieving a complete esterification conversion with some limitations with respect to the transesterification reaction and a FAME yield close to 90.5%.

Producing and Testing the Properties of Biodiesel Sourced from Hemp Oil

Organic matter is converted into a variety of fuels, including potential replacements for transport fuels. New sources of raw materials are being sought for their acquisition. One such raw material that is currently attracting a growing degree of attention is hemp. The objective of this study was to produce biodiesel from hemp oil to ascertain its selected properties and to compare them with the properties of biodiesel obtained from rapeseed oil and the properties of diesel fuel. A reactor designed for the non-industrial, local conversion of available raw materials into fatty acid esters was used for the manufacture of biodiesel. The properties of hemp oil biodiesel were evaluated in comparison with those of rapeseed oil biodiesel, with properties of diesel fuel, and with the requirements set forth in the EN 14214 standard, pertaining to the specification of fatty acid methyl esters for utilization in compression-ignition internal combustion engines. The kinematic viscosity value of the hemp oil biodiesel yielded just below the upper limit defined in the standard. Furthermore, research has demonstrated that such biodiesel contains a considerable proportion of esters of linoleic and linolenic acids, which are susceptible to oxidation. The content of linolenic acid ester in esters produced from hemp oil is clearly higher than the content of this ester in esters obtained from rapeseed oil. This higher content contributes to the high value of the iodine number, significantly exceeding the standard requirements. The remaining designated properties of hemp oil biodiesel are in accordance with the requirements laid down in the standard and exhibit similarities to those of rapeseed oil biodiesel. Further research is recommended to enhance the characteristics of hemp oil biodiesel and its utilization in compression-ignition engines.

Comparative lipidome and transcriptome provide novel insights into zero-valent iron nanoparticle-treated Fremyella diplosiphon.

Understanding the intricate interplay between nanoparticle-mediated cyanobacterial interactions is pivotal in elucidating their impact on the transcriptome and lipidome. In the present study, total fatty acid methyl esters (FAMEs) in the wild-type (B481-WT) and transformant (B481-SD) Fremyella diplosiphon strains treated with nanoscale zero-valent iron nanoparticles (nZVIs) were characterized, and transcriptome changes analyzed. Comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry revealed a 20-25% higher percentage of FAMEs in nZVI-treated F. diplosiphon strain B481-SD compared to B481-WT. Accumulation of alkanes was significantly higher (> 1.4 times) in both strains treated with 25.6 mg L-1 nZVIs compared to the untreated control. In addition, we observed significantly higher levels of monounsaturated FAMEs (11%) in B481-WT in 3.2 (11.34%) and 25.6 mg L-1 (11.22%) nZVI-treated cells when compared to the untreated control (7%). Analysis of the F. diplosiphon transcriptome treated with 3.2mg L-1 revealed a total of 1811 and 1651 genes that were differentially expressed in B481-SD and B481-WT respectively. While the expression of iron uptake and ion channel genes was downregulated, genes coding for photosynthesis, pigment, and antioxidant enzymes were significantly (p < 0.05) upregulated in B481-SD treated with 3.2 mg L-1 nZVIs compared to the untreated control. This study on essential FAMEs and regulation of genes in nZVI-treated F. diplosiphon strains provides a molecular framework for optimization of metabolic pathways in this model species.

Phycoremediation of rice bran oil processing wastewater and biodiesel production using green microalgae, Scenedesmus obliquus: a green approach to environmental protection and remediation.

The current study investigated the enhancement of biomass in S. obliquus, using rice bran oil processing (RBOP) wastewater in different RBOP wastewater concentrations, while also aiming to produce biofuel and treat the wastewater simultaneously. The strain was grown in Blue Green-11 (BG11) media as well as RBOP wastewater at different wastewater concentrations with distilled water at 10%, 25%, 50%, 75%, and 100% under controlled experimental settings. The study findings demonstrated a notable enhancement in the characteristics of RBOP wastewater during a 16-day growth period. The 75% RBOP wastewater concentration demonstrated superior efficacy as a growth medium for producing biomass as well as lipids, among other wastewater concentrations. Accordingly, physicochemical parameters and heavy metal percent of the RBOP wastewater were assessed. The collected biomass was employed in the production of biodiesel, and the fatty acid methyl esters (FAME) were measured, along with an assessment of its characteristics. Physicochemical analysis indicated that S. obliquus was able to effectively decrease levels of nitrate, phosphate, sulfur, and chemical oxygen demand (COD) in RBOP wastewater. The heavy metal reduction percentages for iron (Fe), zinc (Zn), nickel (Ni), copper (Cu), and arsenic (As) were 69.43%, 72.94%, 72.99%, 90.49%, and 91.5%, respectively, following treatment with S. obliquus. FTIR indicated the existence of various functional groups (including alcohol, carboxylic acid) on the surface of the microalgal biomass. The FAME profile of S. obliquus exhibited a moderate level of saturated and unsaturated fatty acid content. S. obliquus demonstrated significant phycoremediation capabilities and potential for lipid production. This study has indicated that S. obliquus is a potential candidate for the treatment of wastewater.

Bimetallic Rex-Ru/C catalyst for fatty acid esters to diesel-range alkanes under low temperature

ABSTRACT The hydrogenation of bio-based oil into biodiesel is a key strategy in reducing reliance on fossil fuels. However, efficient catalysts are needed to enable low-temperature hydrogenation reactions due to the current high-temperature requirement for bio-based oil hydrogenation. Here, bimetallic catalysts Rex-Ru/C for low-temperature hydrogenation of bio-based oils were prepared. The presence of Re oxides (ReOx) in the catalyst enhances the abundance of weak and medium acid sites, thereby facilitating the adsorption of H2. The DFT calculation shows the introduction of Re also improved the adsorption capacity of the catalyst for fatty acid methyl ester and H2. The Re0.25-Ru/C catalyst exhibits superior conversion, selectivity, and recyclability at low temperatures compared to the previously reported catalysts, achieving 100% conversion of methyl stearate with 100% selectivity toward n-heptadecane (C17) and n-octadecane (C18) (reaction conditions: 150°C, 4 h, 2.5 MPa H2). Moreover, the catalyst also shows excellent hydrogenation activity toward various fatty acids or esters, including methyl palmitate, stearic acid, and palmitate at low temperatures. The Re0.25-Ru/C catalyst showed consistent recycling performance over 9 cycles. The decline in catalytic performance of the catalyst was primarily caused by a reduction in ReOx content, resulting in a decrease in acid site concentration. Consequently, there was reduced adsorption of H2 and oil on the catalyst.

Catalytic Fatty Acid Methyl Esters (FAMEs) Synthesis Using Lepidium aucheri Seed Oil and Its Antibacterial Potential

Catalytic Fatty Acid Methyl Esters (FAMEs) Synthesis Using Lepidium aucheri Seed Oil and Its Antibacterial Potential

Microwave Assisted Biodiesel Production from Waste Cooking Oil Using Steel Slags as Catalyst

AbstractAn innovative catalytic system for biodiesel synthesis starting from waste biomass (waste cooking oil, WCO) in the presence of waste material (steel slags) as the catalyst under microwave irradiation is described. The reaction conditions were optimized by using response surface methodology (RSM) based on Box‐Behnken Design (BBD) taking time, temperature, and catalyst weight as factors. The optimum conditions, leading to 97 % conversion of WCO into FAMEs (fatty acid methyl esters) were found to be: 18 min reaction time, 134 °C and 380 mg of catalyst for 1.0 mL of WCO. The recyclability of the catalyst was tested at different experimental conditions, and by increasing the reaction times for subsequent cycles, the catalytic efficiency remained steady. The alkalinity of both as‐received steel slags and steel slags recovered after three reaction cycles was tested with the Hammett indicator method. The steel slags were also characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X‐ray Fluorescence (ED‐XRF), X‐Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), X‐ray Photoelectron Spectroscopy (XPS).

Corrosion Rate of Ship Fuel Pipes Due to the Use of HSD B0 and HSD B30

Pipes are an important part of the world of shipping because most ships use pipes as a medium for transferring liquids from one tank to another or from one place to another. The use of biodiesel B30 as a mixture of diesel fuel high speed diesel (HSD) has an impact on the engine and other components. The method used in calculating the corrosion rate is the loss method which refers to the ASTM G31-71 standard using a test kit flow loop and potentiostat. Corrosion rate obtained by using a test toolflow loop until the 75th day that the B0 corrosion rate was 0.003534 mm/y and the B30 corrosion rate was 0.0047366 mm/y. The corrosion rate obtained by using a potentiostat corrosion testing tool showed that the B0 corrosion rate was 0.00000016 mm/y and the B30 corrosion rate was 0.00000963 mm/y. There is an additional 30%fatty acid methyl ester (FAME) palm crude oil can increase the corrosion rate.

High temperature perturbs physicochemical parameters and fatty acids composition of safflower (Carthamus tinctorius L.)

Future climates will realise increasingly frequent extreme weather events, which will impact on the quantum and quality of crop production. While effects of extreme heat on crop production have been well studied hitherto, there remains a dearth of knowledge pertaining to the impacts of extreme heat on grain quality. As such, our purpose here was to evaluate the effects of terminal heat stress on the physicochemical properties and composition of seed oil of safflower plants. Using two contemporary cultivars with varying genetic tolerance to heat stress (Faraman and Sofeh), we found that exposure to extreme heat reduced grain yield by 53–57%. Four fatty acids (palmitic, stearic, oleic and linoleic acid) comprised 96–99% of total fatty acid methyl esters; relative composition varied in response to heat stress and other environmental conditions. In the first experimental year (2017-18), saturated fatty acids in Sofeh and Faraman cultivars increased by 69% and 18% respectively, while unsaturated fatty acids decreased by 9% and 4%, respectively. In the second experimental year (2018-19), saturated fatty acids increased by 10% in Sofeh and by less than 1% in Farman, while unsaturated fatty acids in both cultivars were not significantly altered. Physicochemical parameters differed across years and cultivars; exposure to high temperature increased chlorophyll and carotenoid content in Sofeh, but decreased the said parameters in Faraman. In 2017-18, effects of heat stress on thiobarbituric acid were variable, but in 2018-19, thiobarbituric acid increased in both cultivars. In all cases, saponification and iodine content increased in response to heat stress. In sum, the fatty acid profile of safflower exposed to terminal heat stress was less affected compared with oil physicochemical parameters, due to greater temperature sensitivity of the latter.

Analysis and Characterization of Pericopsis mooniana Seed Oil for Potential Applications in Cosmetics and Nutritional Supplements

Pericopsis mooniana is renowned for wood applications, while its bark and leaves find uses in ayurvedic medicine. The shifting of global cosmetic and nutritional supplement industries towards plant-based oils has led to explore novel sources. No prior studies were done on P. mooniana seed oil. Therefore this study aims to characterize the seed oil of P. mooniana by determining Fatty Acids (FA) composition as their methyl esters, nonpolar constituents in unsaponifiable matter, and other physio-chemcial properties. The oil was extracted using the soxhlet extraction method. Ash and moisture contents of seeds, Acid Value (AV), Iodine Value (IV), smoke point and thermal stability of oil were also determined. Prepared fatty acid methyl esters and chemical constituents in unsaponifiable matter were identified and quantified using Gas Chromatography-Mass Spectrometry method. Results indicated a substantial oil yield of 36.71± 0.01% with moisture content of 5.60 ± 0.19%, ash content of 3.65 ± 0.38%, AV of 2.97 ± 0.40 mg KOH/g, IV of 16.02 ± 0.14 g I2/100g, smoke point of 233.6 ± 8.57°C, decomposition temperature of 409.95 ± 1.74°C and yield of unsaponifiable matter of 1.35 ± 0.01%. The dominant FAs are oleic (41.02%) and linoleic (38.12%) acids. Major unsaponifiable matter constituents are squalene (4.01 mg/g), beta.-sitosterol (2.63 mg/g), stigmasterol (1.23 mg/g), phytol (1.45 mg/g), geranylgeraniol (1.03 mg/g) and amyrin (0.95 mg/g). Based on the finding of this study, it can be concluded that P. mooniana seed oil has the potential to be utilized in both cosmetic and nutritional supplement industries.

Evaluating Biodiesel Properties from Waste Cooking Oil for Sustainable Energy Applications

Biodiesel was synthesized from used vegetable oils collected from local restaurants in Minna, Niger State, Nigeria, using a base-catalyzed transesterification process with methanol and potassium methoxide as the catalyst. The physicochemical properties of the produced biodiesel, such as density, kinematic viscosity, flash point, pour point, cetane number, and calorific value, were evaluated and compared against conventional diesel fuels and biodiesel from other sources like Jatropha, Neem, and Castor oils. Gas chromatography (GC) was used to analyze the fatty acid methyl esters (FAMEs) composition, identifying methyl oleate, methyl linoleate, methyl palmitate, and methyl stearate as the primary components. The produced biodiesel exhibited favourable properties, including a cetane number and flash point within recommended ASTM standards, indicating efficient ignition and safe storage characteristics. Additionally, the calorific value and kinematic viscosity of the biodiesel were found to be comparable to conventional diesel, making it a viable blend for diesel engine applications.

Analysis of the nutritional composition of Bahraini breed camel (Camelus dromedarius) milk: fatty acid, mineral, phenolic, and antioxidant content

Camels live under extremely arid conditions, yet they can produce more milk than any other animal in the desert ecosystem. They also have a longer lactation duration as well as low nutrition requirements. This study aims to determine the fatty acids profile, minerals, antioxidant activity and total phenols/flavonoids content, in camel milk of the species Camelus dromedarius in Bahrain. Gas chromatography was employed to analyze the fatty acid methyl esters obtained after the extraction of fatty acids. Mineral concentrations were measured by an Inductively Coupled Plasma Optical Emission Spectrometer. Antioxidant measurements included total phenolic content by the Folin-Ciocalteu method, total flavonoid contents by AlCl3 colorimetric method, and total antioxidant activity by the ferric reducing antioxidant power assay. The fatty acids analysis (median(interquartile range) %) showed that the most predominant fatty acids were unsaturated fatty acids (50.40(6.76) %), which were slightly higher than saturated fatty acids (49.60(12.17) %). The most abundant saturated fatty acids were C16:0 (26.73(6.73) %), C18:0 (12.32(4.28) %), and C14:0 (10.55(2.86)%). Monounsaturated fatty acid 18:1n9 was 31.5(5.66) %, and 16:1n7 was 12.75(2.19)%, while the major omega-3 was C18:3n3 (3.91(0.71) %). The main omega-6 were C18:2n6 and C18:3n6, accounting for 1.30(0.35) % and 0.94(0.21) %, respectively. The mineral content of camel milk varied, with the presence of macro minerals such as calcium (699.60 mg/L), sodium (855.18 mg/L), magnesium (9.33 mg/L) and potassium (87.09 mg/L). The results showed that camel milk has considerable values of total antioxidant activity (4.75(1.71) mmol/g), total phenolic contents (20.24(11.18) mg GAE/L) and total flavonoid contents (31.74(20.72) mg CE/L). In conclusion, although the (poly)phenol content in camel milk is relatively lower compared to certain plant-based sources, it can represent a good source of antioxidants, in addition to a significant content in unsaturated fatty acids and minerals, further enhancing its nutritional value for human health.

INVESTIGATION OF THE CATALYTIC ACTIVITY OF HYDRATED LIME CA(OH)2IN THE PROCESS OF TRANSESTERIFICATION OF VEGETABLE OILS

Currently, humanity is facing two existential problems: the constant reduction of fossil fuel supplies, primarily crude oil, and global climate change, which is a direct consequence of the increasing use of fossil fuels both in industry and in the transport sector[1,2].One of the possible solutions for these problems arebiofuels, fuels obtained from renewable raw materials, as it isbiodiesel [2], which attracted attention due to characteristics such as high degradability, non-toxicity and low emission of carbon monoxide, particulate matter and unburned hydrocarbons, as well as the possibility of being used either in a mixture with fossil with diesel or independently as 100% biodiesel fuel[3,4,5,6].Heterogeneous catalysts in transesterification processes, i.e. biodiesel production, have been an area of significant and extensive research for many years.It is noticeable that there are significantly fewer works in which the application of Ca(OH)2, was investigated, and the published works show conflicting results, both in terms of its catalytic activity and in terms of the achieved yield of fatty acid methyl esters (FAME).The main goal of this work was to analyze the physico-chemical, chemical, mineralogical, morphological and surface characteristics of hydrated lime produced by Stamal Ltd.Kreševo, with the aim of examining the possibility of its application as a catalyst in the process of transesterification of vegetable oils.The obtained results unequivocally show that by using this hydrated lime as a catalyst in the transesterification process of rapeseed oil, it is possible to achieve a yield of methyl esters that meets the minimum limit of 96.5% prescribed by the European standard for biodiesel, EN 14214. KEYWORDS:biodiesel, heterogeneous catalysts, hydrated lime

Research Progress in the Synthesis of N-Acyl Amino Acid Surfactants: A Review

This paper reviews the research progress in the synthesis of N-acyl amino acid surfactants, including chemical synthesis methods, enzymatic synthesis methods, chemo-enzymatic methods, and fermentation methods. Chemical synthesis is currently the main route for laboratory and industrial synthesis, including methods such as direct dehydration condensation of fatty acids, amidation of fatty acid anhydrides, carbonyl addition of fatty amides, amidation of fatty acid activated esters, amidation of fatty acid methyl esters, amidation of oils and fats, hydrolysis of fatty nitriles, and Schotten–Baumann condensation. Enzymatic synthesis has the advantages of mild reaction conditions and being green and pollution-free, but the yield is relatively low. The chemo-enzymatic method combines the advantages of enzymatic and chemical methods, but it has not been widely promoted. Fermentation methods have low production costs and are environmentally friendly but the technology is not yet mature. This paper elaborates on the principles, advantages, and disadvantages of each synthesis method and provides an outlook on future research directions.

Boosting bio-lipids hydrodeoxygenation via highly dispersed and coking-resistance bimetallic Ni-La/SiO2 catalyst

A highly dispersed and coking-resistance bimetallic Ni-La/SiO2 catalyst was prepared for the selective hydrodeoxygenation (HDO) of fatty acid methyl esters (FAMEs) and non-edible bio-lipids to hydrocarbon compounds. Under optimum conditions, full conversion of methyl palmitate (MP) and 97.6% selectivity for pentadecane (PD) were achieved. The catalyst also exhibited high conversion and excellent desired product selectivity for the HDO of various model FAMEs, fatty acids, trilaurin, jatropha oil (JO) and waste cooking oil (WCO). Multiple characterizations show that the embedding effect (metal−support or metal−metal interaction) associated with the introduction of metallic La not only contributes to the formation of well-dispersed Ni particles and abundant active Niδ+−OV−LaOx species, but also prevents the migration and sintering of metallic Ni particles at high temperatures. Furthermore, the mutual transformation of the La2O3 and La2O2CO3 crystal phases effectively inhibits coke deposition on the catalyst surface during the reaction process, resulting in remarkable stability and reusability of the catalyst. A plausible reaction network and mechanism for the catalytic HDO of MP over Ni-La/SiO2 catalyst were proposed. This method of constructing a catalytic system can provide a basis for the development of efficient catalysts for the HDO of non-edible bio-lipids.

Cold-Active Lipase from the Ice Cave Psychrobacter SC65A.3 Strain, a Promising Biocatalyst for Silybin Acylation.

Cold-active lipase from the psychrophilic bacterial strain Psychrobacter SC65A.3 isolated from Scarisoara Ice Cave (Romania) was cloned and characterized as an extremophilic biocatalyst for silybin acylation. Structural analyses highlighted conserved motifs confirming a functional lipase and the presence of primary structure elements for catalysis at low temperatures. The recombinant enzyme (PSL2) heterologously expressed in Escherichia coli was purified in one step by affinity chromatography with a yield of 12.08 ± 1.72 µg L-1 of culture and a specific activity of 20.1 ± 3.2 U mg-1 at 25 °C. Functional characterization of PSL2 showed a neutral (7.2) optimal pH and a high thermal stability up to 90 °C. Also, this lipase was stable in the presence of different organic solvents, with 60% residual activity when using 20% DMSO. Kinetic measurements indicated performant catalytic efficiency of PSL2 for different short and long chain fatty acids, with Km in the mM range. The catalytic activity of PSL2 was assessed for silybin acylation with various fatty acids and fatty acid methyl esters, demonstrating a 90% silybin conversion when methyl decanoate ester was used. This result clearly highlights the biocatalytic capability of this new cold-active lipase.

Exploring Alkali Hydroxide Influence on Calcium Titanate Formation for Application in Biodiesel Catalysts

Biodiesel has been recognized as the most widely utilized biofuel around the world due to its significant role in reducing the consumption of crude oil and lowering environmental pollution levels. By serving as a renewable alternative to fossil fuels, bioethanol helps decrease greenhouse gas emissions and contributes to a more sustainable energy future. Traditionally, alkali hydroxides like NaOH and KOH have been mainstays in biodiesel synthesis. However, their overuse can lead to unwanted byproducts and operational complexities. Since calcium titanate can occur at a strong base condition, it presents an alternative avenue worth exploring. In this study, we investigate the influence of alkali hydroxides, namely LiOH, NaOH, and KOH, on the formation of calcium titanate through hydrothermal methods, with varying heating times. We aim to understand how different hydroxides affect the synthesis process and the resultant properties of calcium titanate. We delve into the vibrational properties of Ca‒O‒Ti and Ti‒O bonds using Fourier transform infrared spectroscopy (FTIR), confirming the presence of calcium titanate (JCPDS No.42-0423) through X-ray diffractometry (XRD). This thorough characterization provides insight into the structural integrity and composition of the synthesized materials. Moreover, scanning electron microscopy (SEM) reveals the intriguing cube-like morphology of calcium titanate, offering visual evidence of its unique structure. The fatty acid methyl ester Iimpressively, our results show that calcium titanate synthesized in 7 M NaOH and KOH solutions, heated for 24 hours, emerges as a promising biodiesel catalyst. We observe fatty acid methyl ester provides the percentages of 63.67% and 90.02%, respectively, indicating the catalytic efficacy of these materials in biodiesel production. These findings not only contribute to the understanding of calcium titanate synthesis but also pave the way for a sustainable future in biodiesel production by introducing efficient and eco-friendly catalysts.