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Over the year’s world has seen a noteworthy rise in pollution and diminution in fossil fuels as a consequence biodiesel was thought of an auxiliary fuel which could turn down the usage of conventional fossil fuels. The value of FFA in Gossypium (cotton) seed oil to be 1.8% retrieved from titration result. Therefore, single stage transesterification phenomena were used for biodiesel production. Cottonseed crude oil (800 ml) was heated beforehand to 131°F, methanol (molar ratio 9:1) and KOH pellets (4% wt.) were mixed to form potassium methoxide which is a strong caustic. Biodiesel formed was washed once for the removal of any impurities of glycerin. The yield of the result was found to be 93%.Even after considerable edge over the conventional fuel, biodiesel is facing an adverse response because of its poor stability and tendency to get oxidized with the time. Fire point is an important indicator which indicates the tendency of a fuel to support combustion. In this work, efforts have been taken to study the impact of additives like antioxidants and metal adulterants on the fire point of cottonseed biofuel.

This work studied the transesterification reaction of palm kernel oil to produce Biodiesel FAME, using as catalyst KOH incorporated as a potassium methoxide intermediate. The catalytic tests were performed modifying representative variables such as reaction temperature (°C), methanol/oil molar ratio, and catalyst content (%KOH). The experimental data were adjusted to a linear empirical model, finding that the best experimental condition was observed at 50 °C with a methanol/oil ratio of 5.5 and a% KOH of 0.8. Finally, the FAME was characterized by FTIR spectroscopy, gas chromatography, and ASTM quality control techniques for analysis of cold properties, transport properties, and combustion properties. The reaction rate was determined and a reaction mechanism was proposed based on the experimental results.

A formylation of aryl iodides at room temperature using a weaker base KOMe instead of BuLi was developed. The TMS-TMS disilane was discovered to play crucial roles in this formylation. It was found that the MeO− group of KOMe coordinated with two silyl groups of disilane to generate a hypercoordinate silane species. This hypercoordinate silane species reacted with aryl iodide to give an aryl carbanion, which underwent formylation with DMF to give an aryl aldehyde.

Deuterated compounds are of great importance in chemistry and pharmaceuticals. Reductive dehalogenation is one of the most useful methods to incorporate deuterium into molecules. This article briefly discusses the historical development of dehalogenative deuteration reactions that involve transition-metal catalysis, radical halogen abstraction, alkali-metal reductive deuteration, and the recently developed potassium methoxide/hexamethyldisilane-mediated dehalogenation of aryl halides.

During transesterification reactions, catalyst content, free fatty acids (FFA), and water content affect the final ester content, which is also impacted by soap formation that is yet to be completely elucidated. This research aimed to examine the effects of reaction time (0–10 min), FFA content (0.2–1.1 wt%), and potassium methoxide amount (KOCH3 0.5–2.42 wt%) during the transesterification reaction of refined palm oil containing 0.49 wt% FFA. Soap formation occurred during the first few seconds of the reaction, and then, the soap content remained relatively constant. From a microscopic point view, soap should act as a mass-diffusion barrier reducing reactant mass fluxes to the reaction zone. High FFA content in palm oil causes high soap formation. A high-water content leads to soap formation in FAME and RPO. FFA contributes to soap formation due to neutralization and saponification reactions. It was found that the optimal catalyst content to meet biodiesel property standards (i.e., particularly that the ester content is greater than 96.5%) was 1.0 wt% of oil. Catalyst addition below 0.7 wt % resulted in diesel that did not meet the required ester content standard. Catalyst addition exceeding 1% did not improve the conversion further, but it increases the production costs. Regarding the effects of the type of catalyst on the 2nd step transesterification of FAME, the use of potassium hydroxide showed more soap formation than potassium methoxide. The results suggest that the drawbacks associated with high catalyst utilization should be addressed.

In this study, research was performed on the interesterification reaction of cotton oil with methyl acetate, using potassium methoxide as catalyst, in the presence of ultrasonic waves. In order to obtain a better understanding of the process variables behavior, a response surface methodology was used along with statistical methods. The experiments were performed with molar ratio varying from 1:8 to 1:24, catalyst percentage of 0.1 to 1.3% (weight), ultrasonic nozzle amplitude varying from 30% to 90% (180 to 540 W) and vibration pulse varying from 50% to 90%. Process variables were optimized with the optimal molar ratio of 1:14.87, catalyst concentration of 1.17%, ultrasonic probe amplitude of 67.64% and vibration pulse of 67.30%. The average conversion of triglycerides was found to be 98.12% at the optimal conditions. The experimental data were adjusted to the second-order irreversible reaction approximation model, under optimized conditions, with temperatures of 30, 40 and 50 ºC. Lastly, in comparison to the conventional methodology, a significant increase of 14% of triglycerides conversion utilizing ultrasonic waves was observed.

s An alternative approach to producing biodiesel from spent coffee grounds (SCGs) has been developed with methanol washing applied as a pretreatment step, followed by in-situ transesterification. Under optimal conditions, methanol washing was able to reduce the high acid value of SCGs to 0.78 mg KOH g−1 with a negligible loss of their oil content, which ended up being 11.43% by mass. Pretreated SCGs were then directly treated with a potassium methoxide solution and isopropanol as co-solvents in the in-situ transesterification process. A central composited rotatable design was applied to determine the optimal conditions for KOH concentration and proportion of isopropanol. The results showed that both KOH concentration and proportion of isopropanol had significant effects on the biodiesel yields, residual triglyceride in the biodiesel, and extraction performance (p-value

Fatty acid methyl esters (FAME) also called and accepted as biodiesel, obtained prominent importance in this new era as an alternate fuel for petro-diesel. Microalgae are identified as few of such feedstock for the production of biodiesel. Higher volumes of production per hectare area, fast growing ability and high oil contents are the major advantages of microalgae over the conventional oil yielding crops. Schizochytrium is one of marine microalgae and high lipid content of this microalga is ideal for production of biofuels. Also, Schizochytrium oil is found to have 0.1% free fatty acid content which is well within the recommended value for one-step alkaline transesterification. In this work, the synthesis of bio-diesel was carried out from Schizochytrium oil with the addition of potassium methoxide (a mixture of methanol and KOH). Aiming at the higher yield of FAME, essential amounts of methanol, catalyst, and reaction time were optimized. The yielding of FAME was confirmed by Gas Chromatography with Mass Spectroscopy (GC-MS) for each trial of experiment. A conversion efficiency of 99.99% was observed through GC-MS analysis for a 30% v/v methanol, 0.4% w/v KOH and 90 min reaction time at reaction temperature of 60°C. The results were complemented by proton nuclear magneto resonance (1H NMR) spectra and it is found that the synthesized fuel properties are well within the limits of ASTM standards.

A study of the soybean oil transesterification reaction with dimethyl carbonate (DMC) catalyzed by potassium methoxide prepared through recrystallization process in presence of methanol was done. Reaction variables were analyzed viz. temperature of 40, 60 and 80 °C, DMC to oil molar ratio of 2:1, 4:1, 6:1, 8:1 and 10:1, and catalyst concentration of 1, 1.5 and 2 wt% in relation to oil, aiming to obtain the best condition for reaction. Triglyceride conversion of 99% was achieved for 6:1 DMC:oil molar ratio, 2.0 wt% of catalyst concentration and 80 °C after 15 min of reaction. Experiments were carried out to investigate methanol effects in DMC/oil medium and also to compare reactions with recrystallized and heterogeneous catalysts. Potassium methoxide recrystallized in presence of methanol achieved a triglyceride (TG) conversion higher than 99% while only a 20% TG conversion was achieved from heterogeneous reaction at same condition. Potassium quantification in biodiesel phase was done in order to investigate the homogeneous pathway catalysis in recrystallized catalyst reaction.

An efficient cobalt catalyst system for the Suzuki–Miyaura cross-coupling reaction of arylboronic esters and aryl halides has been identified. In the presence of cobalt(II)/terpyridine catalyst and potassium methoxide, a diverse array of (hetero)biaryls have been prepared in moderate to excellent yields.

The efficiency of two processes to remove the potassium methoxide catalyst after the chemical interesterification of sunflower oil with methyl acetate was examined in this work. The two processes were acid neutralization and dry washing. Several acids were used as neutralization agents to form potassium salts. Among them, phosphoric acid produced the best results, forming monopotassium phosphate salt as a neutralization product. The influence of the acid to catalyst molar ratio was also studied, determining the final water content to avoid a contamination of subsequent methyl acetate purification processes. Several commercial adsorbents (Filtracel, Magnesol, and bentonite) were used in the potassium removal using dry washing. An initial filtration of the undissolved catalyst improved the adsorption process. The experimental results were modeled using a type III Brunauer isotherm. With the dry washing, the partially esterified glycerol content was not affected, but surprisingly, the water content was incre...

Herein, aiming at optimization of the polymerization process leading to a family of hole- and electron-conducting 1,1,2,2-ethenetetrathiolate-based polymers, such as poly(nickel-1,1,2,2-ethenetetrathiolate), poly[Kx(Ni-ett)], we investigated transformations of the monomer precursor 1,3,4,6-tetrathiapentalene-2,5-dione (TPD) occurring under polymerization conditions. We found that only one ring of TPD opens upon its reaction with potassium methoxide under inert conditions at room temperature which leads to the formation of potassium 2-oxo-1,3-dithiol-4,5-dithiolate (K2[3]). Heating of K2[3] under reflux in methanol solution under inert conditions opens the second ring, however the resulting product is not potassium ethenetetrathiolate (K4[2]), the product of an exhaustive methanolysis of TPD, but potassium tetrathiooxalate (K2[4]), the product of the decarbonylation of K2[3]. Preliminary experiments reveal that the involvement of K2[4] in the polymerization process is beneficial for reproducible formation of high quality 1,1,2,2-ethenetetrathiolate-based polymers suitable for thermoelectric applications.

It was stated that initiation in ring opening polymerization of styrene oxide depends on the kind of potassium alkoxide activated by 18-crown-6 used. In the presence of potassium methoxide the oxirane ring opening occurs exclusively in the β-position and not in the β or α position, i.e., contrary to the previous data. A similar result was obtained in the systems initiated with potassium t-butoxide, 2-methylpropoxide and 1-phenylethoxide. Unexpectedly, potassium i-propoxide and 1-methylpropoxide open the oxirane ring in the β or α position. In all polymerizations, deprotonation of methine group in the monomer takes place under the influence of the initiator and in chain transfer reaction to the monomer. It leads to the formation of macromolecules with unsaturated starting group. However, deprotonation of methylene group in the monomer does not occur. Applying of potassium hydroxyalkoxides, i.e., monopotassium salt of dipropylene glycol or tripotassium salt of 2,2,6,6-tetrakis(hydroxymethyl)cyclohexanol it was possible to synthesize PSO-diols and PSO-pentols without unsaturation. Molar masses of polymers (M n = 1700–4800 Da) are much higher than reported in literature for other anionic systems. Dispersity of polymers is rather low (M w/M n = 1.07–1.15) indicating relatively high rate of initiation and cation exchange reaction.

Dialkyl carbonates were found to regio- and stereoselectively add to terminal alkynes in the presence of catalytic amounts of potassium methoxide. Various synthetically meaningful aryl- and heteroaryl-substituted (E)-β-alkoxyacrylates were thus obtained in high yields and with near-ideal atom economy.

Cerbera Odollam (sea mango) is a proven promising feedstock for the production of biodiesel due to its high oil content. Fatty acid methyl esters (FAME) were produced as the final reaction product in the transesterification reflux condensation reaction of sea mango oil and methyl acetate (MA). Potassium methoxide was used as catalyst to study its reacting potential as a homogeneous base catalyst. The initial part of this project studied the optimum conditions to extract crude sea mango oil. It was found that the content of sea mango sea mango oil was 55%. This optimum amount was obtained by using 18 g of grinded sea mango seeds in 250 ml hexane. The extraction was carried out for 24 hours using solvent extraction method. Response surface methodology (RSM) was employed to determine the optimum conditions of the reaction. The three manipulated variables in this reaction were the reaction time, oil to solvent molar ratio, and catalyst wt%. The optimum condition for this reaction determined was 5 hours reaction time, 0.28 wt% of catalyst and 1:35 mol/mol of oil: solvent molar ratio. A series of test were conducted on the final FAME product of this study, namely the FTIR test, GC-FID, calorimeter bomb and viscometer test.

The catalytic activity of glycerol-enriched calcium oxide for the alcoholysis reaction between avocado oil and ethanol was investigated. The calcium oxide was derived from Mytilus Galloprovincialis shells. This study systematically examined the influence of temperature, ethanol-to-oil molar ratio, and the catalyst amount on the variation in the concentration of triacylglycerols and biodiesel with reaction time. The interaction between the reaction variables (ethanol-to-oil molar ratio and catalyst amount), their influence on the ethanolysis process, and the optimum variables affecting the process were determined through the response surface methodology. A previously developed mathematical model was applied for the current ethanolysis process, and the model parameters were determined. The ethanolysis reaction occurred between the surface chemisorbed ethoxide ions and oil molecules in the liquid phase, while, the overall process was controlled by the ethanol-adsorption step. The physico-chemical properties of biodiesel, produced using potassium methoxide catalyst, were additionally measured.

Various alkali metal salts were applied as initiators for e-caprolactone anionic ring-opening polymerization in tetrahydrofuran at room temperature. It was observed that potassium methoxide (MeOK), potassium isopropoxide (i-PrOK) and potassium tert-butoxide (t-BuOK) nonactivated or activated by 18-crown-6 (18C6) initiated polymerization mainly by deprotonation of the monomer. In the case of potassium hydride (KH), its basicity increased with the ability of the ligand for cation complexation. For example, KH without ligand or with weak ligands for K+ as 12C4 reacted exclusively by ring opening. However, in the presence of strong ligands, as 15C5, 18C6 or cryptand C222, basicity of H− increased with the ability of the ligand for cation complexation. In the last case, ~ 32% of the monomer was deprotonated. In these systems, gaseous H2 evolved during the initiation. Deprotonation of the monomer by some initiators resulted in macromolecules with reactive aldehyde group or lactone ring as starting groups. They took part in the reaction with potassium alkoxide active centers of growing chains leading to the formation of branched poly(e-caprolactone)s. Sodium hydride (NaH) was inactive, but in the presence of 15-crown-5 or 18-crown-6 initiated polymerization exclusively by ring opening. MALDI-TOF mass spectrometry supported with 13C NMR and SEC was used for analysis of the polymers obtained. Mechanism of the studied processes was proposed and discussed.

Nucleosides containing ester groups that are sensitive to nucleophiles were incorporated into oligodeoxynucleotides (ODNs) through solid phase chemical synthesis. The sensitive esters are located on a purine nucleobase. They are the esters of ethyl, 2-methoxyethyl, 4-methoxyphenyl and phenyl groups, and a thioester. These esters cannot survive the deprotection and cleavage conditions used in known ODN synthesis technologies, which involve strong nucleophiles such as ammonium hydroxide and potassium methoxide (potassium carbonate in anhydrous methanol). To incorporate these sensitive groups into ODNs, the Dmoc phosphoramidites and linker were used for solid phase synthesis, which allowed ODN deprotection and cleavage to be carried out under non-nucleophilic oxidative conditions. Sixteen ODN sequences containing these groups were synthesized and characterized with MALDI MS. In addition, the synthesis and characterization of three ODNs containing a nucleophile sensitive 6-chloropurine using the same strategy are described.

Herein we describe a general, mild and scalable method for deuterium incorporation by potassium methoxide/hexamethyldisilane-mediated dehalogenation of arylhalides. With CD3CN as a deuterium source, a wide array of heteroarenes prevalent in pharmaceuticals and bearing diverse functional groups are labeled with excellent deuterium incorporation (>60 examples). The ipso-selectivity of this method provides precise access to libraries of deuterated indoles and quinolines. The synthetic utility of our method has been demonstrated by the incorporation of deuterium into complex natural and drug-like compounds.

Fatty acid methyl esters (FAME) were synthesized from the waste cooking oil (WCO) by direct transesterification with methanol. The WCO was pretreated to increase the efficiency of FAME production with 1% of potassium methoxide as a catalyst. The free fatty acid of raw source was reduced using 2% of activated charcoal as adsorbent. The process variables were optimized using Box-Behnken design of Response Surface Methodology (RSM), and developed Artificial Neural Network (ANN) model to predict the FAME yield. The highest percentage of conversion (95%) was achieved at optimum conditions, for the catalyst concentration of 1%, alcohol to oil ratio of 6: 1, temperature of 75 degrees C and time of 60 s. The yield of biodiesel was estimated by higher R-2 values of RSM (0.98) and ANN (0.99), respectively. The produced FAME from pretreated WCO at 75 degrees C by microwave irradiation was examined by proton nuclear magnetic resonance (H-1 NMR), carbon nuclear magnetic resonance (C-13 NMR), Fourier transform infrared (FT-IR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS). The esters exhibited their two characteristically strong absorption bands arising from carbonyl (C=O) at 1741 cm(-1) of fresh oil, and CeO stretching between 1300 and 1000 cm(-1) in the FT-IR spectra. A representative spectrum of (CNMR)-C-13 for the FAME from WCO was confirmed the presence of methyl esters in the biodiesel of ester carbonyl (-COO-) and C=O at 174.2 ppm and 51.4 ppm, respectively. The characteristic peak of 1H NMR at 1.00 ppm of methoxy protons was observed as a singlet at 3.67 ppm, which proved occurrence of the methyl ester (CH3COOR). In addition, a significant weight loss at 139 degrees C was observed through thermogravimetric (TG) analyses of FAME.

In this work, methyl esters of Pungamia (MEOP), ethyl esters of Pungamia (EEOP), and ethyl esters of Neem (EEON) were primarily produced by means of transesterification process using sodium methoxide (mixture of sodium hydroxide and methanol) and potassium methoxide (mixture of potassium hydroxide and methanol). Further, the fuel properties such as calorific value, flash point, density and viscosity of methyl and ethyl esters were determined using ASTM specified equipment. Also, the association between different blend ratios and fuel type with fuel properties was gauged with an assistance of two-way analysis of variance. The experimental outcomes revealed that the maximum ester content of bio-diesel was witnessed for potassium hydroxide catalyst and the quantity of catalyst used was less than that with sodium hydroxide for the same mass of the feedstock oil. Overall, the statistical analysis disclosed that there is a significant difference in the fuel properties of the different combination of fuel type a...

Anisoles and substituted anisoles are the main precursors in the process industries which prepare important pharmaceuticals and these can be produced from various reactants in liquid–liquid or solid–liquid phase transfer catalytic reaction mechanisms. The solid–liquid phase transfer catalysed reaction between p-chloronitrobenzene and potassium methoxide (CH3OK) using 18-crown-6 as a phase transfer catalyst for the production p-nitroanisole was investigated. Potassium methoxide was present as the solid phase and the PCNB which was dissolved in Benzene taken as the liquid phase and the catalyst was also in the liquid phase. Experiments were conducted to observe the effect of various process parameters such as degree of agitation, temperature, catalyst concentration, and different solvents on the conversion of PCNB. A kinetic model has been developed for the above-mentioned reaction to predict the reaction rate. From the results it has been observed that the reaction was found to follow the first ord...

Biodiesel is a notable alternative to the widely used petroleum-derived diesel fuel since it can be generated by domestic natural sources such as soybeans, rapeseeds, coconuts, and even recycled cooking oil, and thus reduces dependence on diminishing petroleum fuel from foreign sources. The advantages of biodiesel as diesel fuel are its portability, ready availability, renewability, higher combustion efficiency, lower sulfur and aromatic content, higher cetane number, and higher biodegradability. The main disadvantages of biodiesel as diesel fuel are its higher viscosity, lower energy content, higher cloud point and pour point, higher nitrogen oxide emission, lower engine speed and power, injector coking, engine compatibility, high price, and higher engine wear. Therefore, biodiesel production is confronted with two main tasks: cost reduction and ecological restrictions. Also, beside these objectives, the social involvements of biodiesel production and use must not be neglected. The best decisions regarding all these aspects imply solving optimization problems. Biodiesel is defined as a mixture of fatty acid alkyl esters which are commonly produced from triglycerides and alcohol through trans-esterification reaction in the presence of alkali catalysts. In this work, canola oil and methanol were used in this research as the feedstocks, and potassium hydroxide and potassium methoxide were used as different formulations of catalysts. A laboratory-scale continuous-flow reactive distillation column system was simulated at optimum conditions by Aspen HYSYS Software. The homogeneous alkali and acid catalyzed were applied to the system. The non-catalytic reaction, where the absence of catalyst simplifies the purification procedures and the products can be easily separated. The critical operating conditions and high consumption of methanol and energy make it uneconomical. Based on the optimization of energy integration and methanol recovery strategies, optimization strategies were assessed for saving energy and recovery methanol.

Despite the fragile bio-fuel market of the present day, numerous research works are being carried out all over the globe to discover a viable alternate source to fossil fuels. In this regard, the present study enumerates the production of methyl esters of Pungamia oil by transesterification process. Also, the parameters influencing biodiesel production such as the stirrer speed, reaction time, and quantity of catalyst were studied and discussed. In this work, sodium methoxide (mixture of sodium hydroxide and methanol) and potassium methoxide (mixture of potassium hydroxide and methanol) gave good conversion yields and high quality of biodiesel during transesterification process. Also, the maximum ester content of biodiesel was witnessed for potassium hydroxide catalyst and the amount of catalyst used was less than that with sodium hydroxide for the same mass of the feedstock oil.

Due to the fact that n-butanol can be obtained from renewable biomass, a factorial design of experiments and a central composite design have been used to optimize the transesterification reaction of esterified oil from Crude Jatropha Curcas Oil (CJCO), choosing 1-butanol as reactive. The chosen response was the Fatty Acid Butyl Ester (FABE) yield while the studied variables were the temperature and the potassium methoxide concentration, which both have significance in the process. The FABE yield is augmented by increasing the temperature and the concentration of potassium methoxide in the transesterification reaction. Also, the transesterification reaction of CJCO was studied with four short-chain alcohols (methanol, ethanol, 2-propanol and n-butanol) at different temperatures (45–60 °C) and potassium methoxide concentrations (0.5–1 wt%). Finally, the transesterification reaction was carried out with methanol, ethanol, 2-propanol and 1-butanol and the most important properties fixed in the UNE-EN Standard were measured for each obtained biodiesel.

Catalysts prepared from potassium hydroxide and methanol were tested for methanol carbonylation with CO in the range of 70-90 o C and 20-25 kg/cm 2 (g). Methyl formate was produced selectively under the studied conditions. Lower temperatures and higher pressures enhanced the conversion of CO. Water in the catalyst solution did not completion removed by molecular sieve type 3A, thus the catalyst activity becomes decreased. The influence of inert gases in the gas mixture will cause the partial pressure of CO decreased and also conversion of CO. The reaction rate was first order with respect to the concentration of CO in the gas phase. The activation energy was found to be 14.95 kJ/mol and frequency collision factor is 0.59 min -1 .

BACKGROUND The valorization of CO2 into added-value products appears to be a promising strategy for reducing CO2 emissions. Dimethyl carbonate (DMC) is an environmentally friendly valuable product, with multiple applications, suggested as a potential gasoline additive. However, DMC has traditionally been produced from hazardous phosgene and CO routes, which encourages the interest in developing new processes. The purpose of this work is to study the influence of the membrane in a filter-press electrochemical cell for the valorization of CO2 by the electrosynthesis of DMC from methanol in the presence of the ionic liquid [bmim][Br] and CH3OK and avoiding the addition of carcinogens. RESULTS The performance of the process has been studied using six different anion exchange membranes in comparison with an undivided configuration and our previous study using a cationic exchange membrane. A significant increase in the initial reaction rate is achieved when no membrane is employed. Regardless of which membrane is used, an additional resistance seems to be introduced. A final concentration of 85 mmol L−1 was obtained up to 48 h without membrane, which is a 6-fold increase over our previous work. CONCLUSIONS Although better results were obtained when no membrane was used, study of the divided cell has provided experimental evidence that can serve as a reference for the evaluation of future improvements in this electrosynthesis. © 2014 Society of Chemical Industry

Due to the rapidly growing demand of vegetable oils for edible purposes, the use of non-edible seed oils are gaining much appreciation for biodiesel production. Biodiesel quality and production is affected by several process parameters. The present work was carried out to optimize the operational variables such as methanol/oil molar ratio (3:1–9:1), catalyst concentration (0.50%–1.30%, in relation to oil mass), temperature (45°C to 70°C), and mixing intensity (350–800 rpm) at fixed reaction time (120 min). Biodiesel was synthesized by transesterification of Thespesia populnea seed oil with methanol, using sodium hydroxide, potassium hydroxide, sodium methoxide, and potassium methoxide as catalysts. The optimum set of transesterifications reaction conditions: 7:1 molar ratio of methanol/oil, 65°C temperature, 0.90% (oil weight basis) NaOCH3 catalyst, and 650 rpm yielded 98.1% Thespesia populnea oil methyl esters (TPOMEs)/biodiesel. In summary, it could be concluded that Thespesia populnea oil as a non-food...

Methanol was replaced by dimethyl carbonate for biodiesel production. In the process, fatty acid methyl ester (FAME) was produced through transesterification of soybean oil with dimethyl carbonate (DMC) using potassium methoxide as a catalyst. This method produced a more attractive by-product, glycerol carbonate (GC). Factors affecting the reaction such as vegetable oil to DMC molar ratio, catalyst concentration, reaction time and reaction temperature were optimized. Triglyceride conversion of 95.8% was obtained at the optimized condition. This process provided an insight into the reactivity of DMC at different temperature. Co-production of FAME and glycerol carbonate (GC) proceeded through carboxymethylation reaction because methoxyl group and carbonyl group are generated which subsequently attacked the carbonyl moiety in glyceride molecules to form the required products.

Metal hydroxides and alkoxides are popular base catalysts for production of fatty acid methyl esters (FAME). Hydroxides dissolved in alcohols produce water. Some of that water reacts with triacylglycerols (TAGs) to produce free fatty acids instead of desired FAME, thus decreasing the yield of the transesterification reaction. Metal alkoxides are expensive, their production is hazardous and energy intensive, therefore, less expensive safer and more efficient catalysts for transesterification are desirable. Glycerol derived non-toxic alkoxide base catalysts were synthesized by heating KOH solution (50 wt%) and glycerol at three different mole ratios (KOH: glycerol, denoted KGly, at 1:1, 2:1, and 3:1) under four different vacuum pressures. Transesterification reactions were conducted. The reaction rate and yield of FAME synthesis from TAG achieved by catalyst prepared at 3:1 mole ratio of KOH: glycerol achieved superior or similar FAME yield to conventional potassium methoxide catalyst under same reaction conditions. At 120 s after adding catalyst, the reactions achieved satisfactory yield (74.3–78.9%) which was similar to that of KOCH3 catalyst (77.9%). The reactivity of catalyst at initial stage of the reaction was in the following order: KGly (1:1)

BACKGROUND The electrochemical valorization of CO2 into added-value products appears a promising strategy for reducing CO2 emissions and mitigating climate change. Dimethyl carbonate (DMC) is an environmentally friendly valuable chemical, with multiple applications, and has been suggested as a potential gasoline additive. However, DMC has traditionally been produced from hazardous phosgene and CO routes, which encourages the interest in developing new processes. The aim of this work is to study the valorization process for the direct electrosynthesis of DMC from CO2 and methanol using CH3OK and the ionic liquid 1-butyl-3-methylimidazolium bromide, avoiding the addition of carcinogenic compounds. RESULTS The evolution of the concentration of DMC was studied in a filter-press electrochemical cell with anodic and cathodic compartments separated by a Nafion 117 membrane, operating for 48 h. A final DMC concentration of 15.07 mmol L−1 was observed. Analysis of the by-products obtained in the process revealed the formation of tetramethyl orthocarbonate and dimethoxymethane, which were detected and quantified in the liquid phase. A simplified reaction scheme was also proposed based on the results obtained. CONCLUSION Unlike all previous work that used an undivided cell, the new experimental results of this study using a divided cell can serve as a reference for further research to overcome current limitations. © 2014 Society of Chemical Industry

Due to the limitation of resource, non-edible feedstock has been gaining more attraction as the future feedstock for bio-based industries. Spent coffee grounds (SCGs) are the waste from coffee process which contained various high value products. The purpose of this study is to investigate the possibility of utilizing wet SCGs completely through three processes, antioxidant extraction, biodiesel production, and bio-char production. A semi-continuous process, with four extraction column reactors and peristaltic pumps, was used for extracting antioxidants from wet SCGs with methanol as solvent. Subsequently, potassium methoxide was fed into the reactors containing SCGs residue remaining after antioxidant extraction to produce biodiesel via in-situ transesterification. The defatted SCGs obtained after biodiesel production was further transformed to bio-char via slow pyrolysis. Antioxidant compounds with phenolic content of 10.3 mg gallic acid equivalents/g dried SCGs and antioxidant activity of 48.8 mg butylated hydroxyanisole equivalents/g dried SCGs could be extracted. Moreover, free fatty acid and moisture contents were reduced to levels suitable for in-situ transesterification. A biodiesel yield of 131.1 mg biodiesel/g dried SCGs was achieved, which was exceeded the maximum yield based on calculation. The bio-char produced from defatted SCGs had a heating value of 26.0 kJ/g and was smokeless, which satisfies the Thai community product standard (Per 238/2547). According to inventory analysis, the heat energy from bio-char product was far sufficient to support the whole processes.

Transesterification is the reaction to produce methyl esters in which this reaction’s catalyst involves coconut shell burnt ash at temperature of 550, 600, 650 °C for 8 hours and uses 1%, 2%, 3% (w/w) of ash. Ash used was dissolved in 75 ml of methanol to obtain potassium methoxide compound and was analyzed by AAS (Atomic Absorption Spectrophotometer) to determine potassium content. Palm oil involved in the processing stage of degumming with the addition of 0,6% (w/w) H3PO4 85% to remove gum then followed by an esterification reaction using 3,0% (w/w) H2SO498% as the catalyst to reduce FFA

Intensification of the interesterification reaction of waste cooking oil with methyl acetate using potassium methoxide as a catalyst has been carried out using ultrasonic horn (frequency of irradiation of 22 kHz and rated power of 750 W). Experiments have been performed at different operating parameters viz. reaction temperature (30, 40 and 50 °C), oil to methyl acetate molar ratio (over the range of 1:4 to 1:14), catalyst concentration (0.5, 1.0 and 1.5% by weight of oil) and amplitude of ultrasound (40, 50, 60 and 70%) with an objective of understanding the effect of important operating parameters on the extent of conversion of waste cooking oil to the ester. It has been observed that maximum yield (90%) of biodiesel from waste cooking oil using sonochemical reactors was observed at a molar ratio of 1:12, catalyst concentration of 1.0% and temperature of 40 °C. It is also observed that higher conversion was obtained in the presence of ultrasound as compared to the conventional method. Kinetic studies have been carried out to determine the rate constant by fitting the obtained experimental data to a second-order rate equation. It has been observed that rate constant increases with an increase in temperature and the activation energy is found to be 56.97 kJ/mol.

Oximes are important functional groups in organic chemistry due to their synthetic utility as protecting groups for carbonyl groups and their ability to form other functionalities, 1�4 and their biological activity. 5 Oximes are commonly prepared by condensing aldehydes and ketones with hydroxylamines. These reactions do not always go to completion and reaction times can be long, and therefore there has been interest in more convenient and efficient methods. To avoid the typical disadvantage, conversion of aldehydes and ketones to the corresponding oximes was accomplished by using various catalysts such as organic acid/bases, 1,2,6 AcONa, alumina, 7 TiO2/SO4 2� , 2 silica gel, 8 Oxone®, 9 NaOH, 10 basic ionic liquid 1-butyl-3-methylimidazolium hydroxide, 11 polyoxometalates, 12 Na2SO4, 13 and CuSO4/K2CO3 14 under the solvent, the solvent-free or the microwave conditions. These are one and more drowbacks such as long reaction time, use of catalysts, inconvenients due to solid-sate reaction, low yields and limitaion of some carbonyl compounds. On the other hand, H. Sharghi, et al., 14 reported the catalysis of the stereoselectivity of CuSO4 and K2CO3 in the oximation of aldehydes and ketones under solvent-free conditions. Although this method show high selectivity, it is inconvenient for the large scale experiments and the industrial process due to the solvent-free condition. Therefore, we attempted to develop a more convenient and efficient solution method. According to the literatures, 15 treatment of potassium carbonate with methanol generates slightly the potassium methoxide, which may be useful for forming the free NH2OH from its salts. We describe the oximation of aldehyde and ketone using NH2OH·HCl/K2CO3 in methanol solvent.

The aim of this work was to investigate the commercial mixture of methanolic potassium methoxide as catalyst in chemical interesterification of sunflower oil with methyl acetate. The presence of methanol significantly enhanced the reaction process because it increased the reaction rate, improved the safety of the process and facilitated the manipulation of the catalyst. The reactions were performed at 50 °C using a methyl acetate-to-oil molar ratio (MAOMR) of 12–48 and a catalyst-to-oil molar ratio (COMR) of 0.1–0.2. The optimum conditions were achieved with the MAOMR of 48 and the COMR of 0.1 and the final product composition was: fatty acid methyl esters (77.0 wt.%), triacetin (12.1 wt.%), diacetinmonoglyceride (4.0 wt.%) and diacetin, monoacetin and glycerol fraction (6.8 wt.%). Finally, technical feasibility of the intermediate diacetinmonoglyceride elimination through the addition of higher amounts of methanol was also evaluated.

The reaction of nitric oxide with benzyl cyanide in the presence of potassium methoxide at low temperature gave the dipotassium salt of a bis-diazeniumdiolate 2 in excellent yield. Two new stereospecific syntheses of E or Z 2-(hydroxyimino)-2-phenylacetonitrile from 2 have been found. The thermodynamics of the E/Z isomerization has been investigated spectroscopically in solution, in the solid state by differential scanning calorimetry (DSC), and theoretically in the gas phase. Evidence of catalysis by NO of E/Z oxime isomerization has been observed.