Reflux Temperature Of Methanol Research Articles

Sugar derived hydrochar catalysts for enhanced biodiesel production via esterification

Sugars and sugar alcohols are renewable raw materials which can be used for char production. Their acid-catalyzed hydro-carbonization results in the formation of carbon materials with acidic functional groups on the surface, which makes them suitable to be used as heterogeneous catalysts in esterification reactions. Hydrochars materials were prepared by low-temperature slow carbonization of glycerol, xylitol, sucrose, and glucose in the presence of different amounts of H2SO4 (mass ratios from 1 to 4). The hydrochars were extensively characterized and tested in the methanolysis reaction of oleic acid. All the carbon materials were amorphous with features of polyaromatic sheets with hydroxyl (–OH), carboxylic acid (–COOH), and sulfonic (−SO3H) functional groups. The effect of the oleic acid water content on catalytic performance was studied, showing a strong inhibition effect due to the hygroscopic character of catalysts induced by sulfonic groups and other surface groups with oxygen. Under the conditions evaluated (5 % wt. of catalyst, methanol/oleic acid = 9 M ratio, methanol reflux temperature) the sucrose-derived catalyst prepared with the highest H2SO4 content showed the best performance, leading to methyl oleate yield > 90 % after 2 h of reaction, which is only achieved by the majority of analogous catalysts reported in the literature after 4 to 8 h of reaction. The data showed that there is a correlation between the methyl ester yield and the graphitization of the catalyst, as this makes the catalyst more hydrophobic, which is an advantage in esterification catalysts.

One-Step conversion of high FFA Crude Karanja oil (Pongamia pinnata) to Bio-diesel Using Portland cement as excellent heterogeneous catalyst

Heterogeneous catalyst was prepared from Portland cement. The prepared heterogeneous catalyst was tested for catalytic activity in the transesterification of non-edible, high free fatty acid feedstock, such as crude karanja oil (CKO), for biodiesel production, at methanol reflux temperature. Gas chromatographic (Gc) analysis technique was used to determine the fatty acid methyl ester yield. The preparation of heterogeneous catalyst from low-cost sources, and the use of non-edible feedstock, only at methanol reflux temperature, were all aimed at reducing the cost of biodiesel production. Insight into the catalytic activities of catalyst was obtained by characterizations for their textural properties, using Brunnear-Emmet-Teller (BET) analysis technique, surface scanning electron microscopy (SEM) and electron dispersive x-ray (EDX) for microstructure, surface morphology and chemical composition; x-ray diffraction (XRD) and Fourier-Transform Infra-Red (FTIR) spectroscopy for structural and functional groups analyses, respectively. Differential thermal and thermogavimetric (DTA/TGA) analyses were performed to determine the proper temperature ranges for the dehydration, decomposition, desorption and oxidation of sample via the TGA curves and their melting points and changes in crystal structures via the DTA curves, for effective determination of calcination temperature. The application of Portland Cement-derived heterogeneous catalyst in the transesterification reaction revealed excellent activity in the transesterification of crude karanja oil, with excellent fatty acid methyl ester yield of over 97.87 %. Operational conditions such as methanol/oil mole ratio (1:3 - 18), catalyst loading (3 - 9 % by wt) and reaction time (0.5 – 7 hours), were investigated to obtain the optimum reaction conditions for the feedstock, while the reaction temperature was kept constant at methanol reflux temperature, to minimise cost of production, in line with the objective of this investigation. Calcined heterogeneous catalysts gave over 80% fatty acid methyl ester yields than the raw counterpart, which were attributed to changes in crystal structures and phases of catalysts, observed in the characterization of catalysts, after calcination. Keywords: Portland cement, heterogeneous catalyst, Crude Karanja oil, transesterification reaction, Feedstock

Co-processing lard/soybean oil over Ca-based catalysts to greener biodiesel

Fatty Acid Methyl Esters (FAME) were produced from lard/soybean oil (SBO) mixtures using a calcium-based heterogeneous catalyst. The green catalyst was prepared by scallop shell calcination at a relatively low temperature (800 °C) to minimize energy consumption. Images from Scanning Electron Microscopy showed agglomerates of a few tens micrometers with rhombohedral calcite crystallites studded with lime. X-ray diffractogram of fresh catalyst presented overlapped patterns of calcite and lime In tested conditions (methanol reflux temperature, 5% (fat mass basis), methanol/fat = 12 molar ratio, and 150 min), the FAME yield reached 95% (mass) with SBO. However, only 75% FAME yield was obtained from pure lard since the active sites of the catalyst were partially neutralized by lard acidity. Co-processing lard/SBO mixtures attenuated the undesirable fat acidity drawback allowing FAME yields around 90% for mixtures containing less than 50% (mass) of lard. The low-grade fat content of the processed mixture showed no impact on the glycerin quality. Co-processing lard/SBO is a smart strategy to overcome the low-grade fats acidity in biodiesel production process thus providing a more sustainable biodiesel production route.

Calcium diglyceroxide as a catalyst for biodiesel production

Calcium diglyceroxide (CaD) was used as the catalyst for biodiesel production through oil methanolysis. It was evaluated its catalytic behavior, its air expo- sure tolerance, and the Ca leaching. CaD catalyst was synthesized from food waste scallop shell derived CaO (obtained by calcination at 900 °C) by contacting with a mixture of equal volumes of glycerin and methanol at 65 °C for 2 h. The CaO obtained by calcination of scallop shell was used as reference catalyst. In standard reaction conditions (2.5 h, methanol reflux temperature, 5 wt% (oil basis) catalyst loading, and methanol:oil = 12:1 moral ratio), CaD presented lower catalytic activity than CaO (FAME yield of 92% against 99%, respectively). 24 h repined CaD presented improved catalytic behavior probably due to the formation of surface Ca −OH groups, achieving 96% of FAME yield. Thermogravimetry (TG) data showed that inorganic residue was larger for biodiesel than for glycerin, being CaD catalyst more soluble than CaO. Data showed that CaD is unstable under reaction conditions, suffering leaching, but the absence of Matter Organic Non-Glycerol (MONG) in the glycerin phase allows to neglect the homogeneous contribution of the leached catalyst. CaD formation during reaction contributes to FAME contamination with Ca and promotes catalyst deactivation thus being an undesired occurrence.

Basic ionic liquid functionalized magnetically responsive Fe3O4@HKUST-1 composites used for biodiesel production

The main purpose of this present work is to fabricate a magnetically recyclable solid catalyst for the production of biodiesel to meet the demand of green and clean production. To accomplish this, the core–shell structured Fe3O4@HKUST-1 composites with a magnetic core and a porous metal-organic framework shell were fabricated by using a versatile Layer-by-Layer assembly method, and then basic ionic liquids were encapsulated within the core–shell magnetically responsive material, resulting in a solid hybrid base catalyst. Various techniques such as XRD, TEM, FT-IR, VSM and nitrogen adsorption–desorption were employed to characterize the as-prepared solid base catalyst. The characterization results revealed that Fe3O4 nanoparticles were well coated with metal-organic framework HKUST-1 with the formation of core–shell structured nanocomposites, and moreover the basic ionic liquid had been successfully encapsulated within the magnetic nanocomposites. Furthermore, the solid base catalysts possessed superparamagnetic behavior and high saturation magnetization, allowing them to be facilely separated from the reaction mixture by using an external magnetic filed. The solid base catalyst appeared to be an efficient and environmentally benign catalyst for the transesterification of soybean oil with methanol for the production of biodiesel, giving 92.3% oil conversion to methyl esters within 3 h with a catalyst loading of 1.2 wt% and a methanol/oil molar ratio of 30:1 at reflux temperature of methanol. The solid catalyst could be readily recovered by simple magnetic decantation and reused for several times without significant degradation in its catalytic activity.

Esterification of Oleic Acid with Methanol Using Zr(SO4)2 as a Heterogeneous Catalyst

AbstractThe influence of reaction parameters like molar ratio of methanol to oleic acid, catalyst amount, and reaction temperatures for oleic acid esterification with methanol by using Zr(SO4)2 as a heterogeneous catalyst was investigated. Nearly complete conversion was obtained when the esterification reaction was carried out under optimized reaction conditions in terms of molar ratio of methanol to oleic acid, catalyst amount, reflux temperature of methanol, and reaction time. Furthermore, the kinetics of the esterification reaction was also investigated. The experimental data supported the validity of the suggested Eley‐Rideal model.

The significance of textural and structural properties of potassium loaded y-alumina catalyst on the final catalytic efficiency in the transesterification of sunflower oil

The preparation of y-Al2O3 catalyst support by the modified hydrothermal method and synthesis of KI/y-AI203 catalyst, as well as the investigations of their activities in the reaction of transesterification of sunflower oil were performed in this study. The effect of various process parameters on the transesterification reaction of sunflower oil with methanol and their impacts on the reaction conversions were examined. The y-Al2O3 support and KI/y-AI203 catalysts were characterized by BET, XRD and SEM methods. The physico-chemical properties (surface, textural, structural and morphological) of the catalyst were correlated with its catalytic efficiency. The obtained results implicate that textural and structural properties of the catalyst and also the catalyst activity in the reaction of transesterification essentially depend on textual and structural properties of the y-Al2O3 support. From the optimization of the process parameters, it was found that the optimal conditions for transesterification reaction are: molar ratio of methanol to oil 12:1; stirring speed 600 rpm; the reflux temperature of methanol; the reaction time 5h; the amount of catalyst in the reaction 3 wt.%.

Production of biodiesel through transesterification of soybean oil using ZIF-8@GO doped with sodium and potassium catalyst

One pot encapsulating (hydrothermal) method was used to synthesize ZIF-8@GO hybrid nanocomposites. Na/ZIF-8@GO doped with potassium were synthesized by the hydrothermal treatment of ZIF-8@GO precursor with a 10 M alkali solution containing both NaOH and KOH. The final product (KNa/ZIF-8@GO) was characterized by FTIR, XRD, BET, TGA, and SEM. The structure of graphene oxide remains intact following various modifications, as shown by absorption–desorption analysis, while spectral techniques indicate successful immobilization of the neat ZIF-8 between the GO sheets. Furthermore, soybean oil has been used as the feedstock in the preparation of biodiesel by KNa/ZIF-8@GO-catalyzed transesterification process. The effects of various reaction parameters, including methanol/oil molar ratio, reaction time, catalyst mass, and reaction temperature were investigated. A remarkable conversion of 98% was obtained using a 8% (wt/wt oil) of KNa/ZIF-8@GO catalyst, methanol/oil molar ratio of 18 : 1, and reflux temperature of methanol over a period of 8 h. The solid catalyst can be reused over at least three cycles under mild reaction conditions.

Nanorice-shaped mesoporous V/RSM as an efficient and reusable catalyst for biodiesel production from soybean oil

Sol–gel method was used to synthesize a nanorice-shaped mesoporous V/RSM, which was characterized by FTIR, XRD, BET, UV–Vis and TEM. The mesostructure of silica remains intact after following vanadium modification, as shown by absorption–desorption analysis, while spectral techniques indicate the successful immobilization of the neat vanadium oxide inside the porous silica support. Furthermore, soybean oil was has been used as the feedstock in the preparation of biodiesel by V/RSM-catalyzed transesterification process. Various reaction parameters, including methanol/oil molar ratio, reaction time, catalyst mass and reaction temperature, were studied investigated with regard to their effect on the reaction. A remarkable conversion of 94 % was obtained achieved using a 8 % (wt/wt oil) of V(4.8)/RSM catalyst, methanol/oil molar ratio of 12:1 and reflux temperature of methanol during 8 h. The solid catalyst can be reused over at least six cycles under mild conditions.

Biodiesel production with nanotubular sodium titanate as a catalyst

Sodium titanate nanotubes (STNT) with a chemical formula Na2Ti3O7·nH2O were synthesized and tested as a heterogeneous catalyst in the transesterification of soybean oil with methanol. The catalyst was characterized by N2 physisorption, powder XRD, scanning electron microscopy (SEM-EDX), transmission electron microscopy (TEM) and CO2 temperature-programmed desorption (CO2-TPD). It was found that the prepared catalyst had nanotubular structure, high sodium content (10.3wt.%) and attractive textural characteristics (surface area around 200m2/g and total pore volume of 0.61cm3/g). The influence of the catalyst's loading, methanol to oil molar ratio, reaction time and temperature on the biodiesel yield was investigated. High biodiesel yields (97–100%) were obtained with the STNT catalyst at 8h reaction time at methanol reflux temperature with 1–2wt.% of the catalyst and 40:1 methanol:oil molar ratio. Increase in the reaction temperature to 100–120°C had a positive effect on the biodiesel yield. In this case, 99–100% yields were obtained with a lower catalyst loading (∼1wt.%) and methanol to oil molar ratio (20:1). In addition, it was found that the STNT catalyst does not require high temperature thermal pre-treatment (activation) before the transesterification reaction. The reuse of the same catalyst in the transesterification reaction three times showed a decrease of about 10% in the catalytic activity.

Production of biodiesel by transesterification of soybean oil using calcium supported tin oxides as heterogeneous catalysts

The main objective of this work was to develop an environmentally benign process for the production of biodiesel by using a stable solid base catalyst. To this purpose, different heterogeneous CaO–SnO2 catalysts have been prepared by means of impregnation methods. Various techniques such as X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were applied for the catalyst characterization. The transesterification of soybean oil with methanol, to produce biodiesel, was carried out under batch conditions at refluxed methanol over the CaO–SnO2 catalysts. The catalytic activity is found to be highly dependent on the Ca/Sn ratio and calcination temperature. The solid catalyst with the Ca/Sn molar ratio of 4:1 and calcined at a temperature of 973K, performed the best activity, reaching the conversion to methyl esters of 89.3% after 6h of reaction at methanol reflux temperature (343K) when a methanol/oil molar ratio of 12:1 and catalyst dosage of 8wt.% were employed. Further, the solid catalyst is proved to be stable and durable for the transesterification reaction.

A new heterogeneous acid catalyst for esterification: Optimization using response surface methodology

Studies on heterogeneous acid catalysts for converting free fatty acids into biodiesel have been intensified over the years. This paper focuses on the optimization of a new catalyst system, ferric-alginate as a heterogeneous acid catalyst to esterify lauric acid into methyl laurate. Methanol to lauric acid molar ratio and catalyst amount was optimized using response surface methodology (RSM). The best reaction conditions to achieve methyl laurate yield of 99% was found to be 0.16:1 ferric-alginate to lauric acid mass ratio and 16:1 methanol to lauric acid molar ratio. The reaction time and temperature was fixed at 3h and methanol refluxing temperature, respectively. The optimized reaction conditions were also used to esterify palm fatty acid distillate to give 89% methyl esters conversion. The acid value of palm fatty acid distillate (PFAD) was reduced from 228 to 0.8mg KOH/g PFAD.

Sequential conversion of high free fatty acid oils into biodiesel using a new catalyst system

A sequential esterification and transesterification method was used successfully to convert high free fatty acid oil into biodiesel with almost 100% conversion. The esterification system was catalysed by ferric-alginate beads (0.16:1 ferric-alginate beads to lauric acid mass ratio, 15:1 methanol to lauric acid molar ratio, methanol refluxing temperature (65 °C), reaction time of 3 h) and transesterification was catalysed by boiler ash-calcium oxide mix (3 wt.% boiler ash, calcium oxide according to the stoichiometric amount of water produced in esterification, 15:1 methanol to oil molar ratio, methanol refluxing temperature (65 °C), reaction time of 0.5 h). Calcium oxide played a dual role to absorb the water produced by the esterification of free fatty acid and also as an active species for transesterification of triglycerides. This method was effectively used to convert palm fatty acid distillate to biodiesel with 100% conversion.

Transesterification of Canola Oil Using Marble Dust as a Heterogeneous Catalyst

The transesterification of canola oil with methanol was studied in a heterogeneous system, using marble dust catalyst. Effects of the reaction temperature, catalyst amount, methanol/canola oil molar ratio, and reaction time in biodiesel production were investigated. The results show that the methanol/canola oil molar ratio of 6:1, and the catalyst amount of 3 wt% give the highest FAME yield of 89.32% at a reflux temperature of methanol in 3 h. In order to investigate catalyst stability, the marble dust catalyst was recycled three times. The recovered catalysts provided an 86.71 and 48.95% FAME yield for second and third cycles, respectively.

A new heterogeneous acid catalyst system for esterification of free fatty acids into methyl esters

A new heterogeneous acid catalyst system for production of environmentally friendly fuel, biodiesel was created from ferric sulfate and non-toxic, inexpensive source of biopolymer, sodium alginate. The catalyst, in the form of ferric-alginate beads produced from the reaction of 2wt.% sodium alginate gel with 0.1M ferric sulfate solution gave excellent methyl ester conversion of 98% with mild reaction conditions. The esterification of 0.5g lauric acid was carried out at optimum conditions; 16wt.% of ferric-alginate beads (2.8wt.% Fe) methanol refluxing temperature, 15:1 methanol to lauric acid molar ratio for 3h. The ferric-alginate beads were reusable up to 7 times without any pre-treatment. Characterization of the ferric-alginate beads showed the formation of FeOOH that held the alginate chain in place. Thermal analysis showed that the beads are able to withstand the refluxing temperature without degradation. Iron content was found to be 0.175g Fe/g beads as determined by AAS and 0.189g Fe/g beads as determined by TGA. Easy catalyst separation, reusability and ability of the ferric-alginate beads to esterify lauric acid to give high conversion of methyl laurate makes this catalyst desirable for biodiesel production from high free fatty acid oils.

Catalysts derived from waste sources in the production of biodiesel using waste cooking oil

Catalysts fully derived from waste materials in order to make sustainable chemical reactions have been a recent topic of interest. Calcined (900°C, 2h) calcium oxide (CaO) sourced from waste mud crab shells and cockleshells were mixed in a 1:1 mass ratio to be used for transesterification of waste cooking oil (WCO) at 5wt.% catalyst and a methanol to oil molar ratio of 13:1 for 3h at methanol refluxing temperature to give 98% conversion. Then, boiler ash (BA) from agricultural waste was used to transesterify WCO at 3wt.% catalyst and a methanol to oil molar ratio of 15:1 for 0.5h at methanol refluxing temperature to give 89% conversion. In order to reduce the reaction time (for CaO-catalyzed reaction) and to increase the conversion (for BA-catalyzed reaction) various amounts of BA were added to 5wt.% of mixed CaO and optimized using Central Composite Design (CCD). The optimized conditions predicted by CCD were found to be 3.39wt.% boiler ash, with a reaction time of 32.3min and a conversion of 99.5%. The predicted results agree with the experimental results (3wt.% boiler ash, reaction time of 30min with 99% conversion).

A new catalyst system in transesterification of palm olein: Tolerance of water and free fatty acids

Boiler ash (BA) from oil palm empty fruit bunches used as pseudo-homogeneous base catalyst to transesterify palm olein at mild reaction conditions (3 wt.% BA dried at 105 °C, 2 h; 15:1 methanol to oil molar ratio at methanol refluxing temperature in 0.5 h) yielded 90% methyl esters. However, the catalyst showed low water (0 wt.%) and FFA (1 wt.%) tolerance. Laboratory calcium oxide (Lab CaO, calcined at 900 °C, 2 h) was used as a drying agent and to enhance the FFA tolerance of BA. Transesterification with Lab CaO (5 wt.% Lab-CaO; 13:1 methanol to oil molar ratio) exhibited good tolerance towards 3 wt.% water and 4 wt.% FFA but only 67% methyl esters were produced in 0.5 h. A mixture of BA-Lab CaO (stoichiometric ratio for Ca(OH) 2 formation) catalyzed transesterification yielded 95% methyl esters in 0.5 h and with higher water (3 wt.%) and FFA (4 wt.%) tolerance.

Preparation and Characterization of CaO Nanoparticles/NaX Zeolite Catalysts for the Transesterification of Sunflower Oil

Biodiesel is produced by the transesterification of oil triglycerides with methanol or ethanol, in the presence of a homogeneous or heterogeneous catalyst. This study aims to report the results of the transesterification of sunflower oil with methanol to produce biodiesel using CaO nanoparticles supported on NaX zeolite as catalyst. The effect of the CaO nanoparticles concentration on the NaX zeolite surface was studied in the range of 5−25 wt %. The transesterification reaction was carried out at reflux temperature of methanol, atmospheric pressure, a reaction time of 6 h, and with a 6:1 molar ratio of methanol to sunflower oil. Catalyst characterization was carried out by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. It was concluded that methyl esters content is highly influenced by basicity and that the best catalyst was the one holding 16 wt % CaO nanoparticles. The produced biodiesel was 93.5% methyl esters and was found to fulfill the specifications of Europ...

Preparation of Na doped SiO2 solid catalysts by the sol-gel method for the production of biodiesel from jatropha oil

A new solid catalyst, Na/SiO2, which have come in demand recently due to environmental concerns is prepared using the sol gel method by transesterification of jatropha oil with methanol to produce a biodiesel fatty acid methyl ester. Na/SiO2 with a loading of 50:50 molar ratio Na/Si, calcined at 600 °C exhibited the best catalytic activity for the reaction. The conversion of vegetable oil is found to be 99%. The optimum reaction conditions are achieved at the reflux temperature of methanol (65 °C), with a 1:15 molar ratio of methanol to oil and a catalyst amount of 6 wt%. The catalyst showed high activity under mild conditions and at a relatively short reaction time of 45 min.

Biodiesel synthesis using calcined layered double hydroxide catalysts

The catalytic properties of calcined Li–Al, Mg–Al and Mg–Fe layered double hydroxides (LDHs) were examined in two transesterification reactions, namely, the reaction of glyceryl tributyrate with methanol and the reaction of soybean oil with methanol. While the Li–Al catalysts showed high activity in these reactions at the reflux temperature of methanol, the Mg–Fe and Mg–Al catalysts exhibited much lower methyl ester yields. CO2 TPD measurements revealed the presence of sites of weak, medium and strong basicity on both Mg–Al and Li–Al catalysts, the latter showing higher concentrations of medium and strong base sites; by implication, these are the main sites active in transesterification catalyzed by calcined Li–Al LDHs. Maximum activity was observed for the Li–Al catalysts when a calcination temperature of 450–500°C was applied, corresponding to decomposition of the layered double hydroxide to the mixed oxide without formation of crystalline lithium aluminate phases.