Mass Ratio Of Catalyst Research Articles

<b>Highly active CaO for the transesterification to biodiesel production from rapeseed oil</b>

The catalytic performance of commercial CaO modified by trimethylchlorosilane (TMCS) for transesterification of rapeseed oil and methanol to biodiesel production was studied. It was found that the fatty acid methyl esters (FAME) yield of the modified CaO was greatly enhanced from 85.4% to 94.6% under 65 oC with 15:1 molar ratios of methanol/oil by using 5 wt.% catalyst (weight to oil). The possible reason lies on promoting the absorption of grease to modified CaO surface. Both the characterization of the catalyst and the effects of various factors such as mass ratio of catalyst to oil, reaction temperature and molar ratio of methanol to oil were investigated.KEY WORDS: Biodiesel, Base catalyst, CaO, Modification Bull. Chem. Soc. Ethiop. 2011, 25(1), 37-42.

Nano-porous Composites Based on Heteropolyacid Functionalized Ionic Liquid: Synthesis, Characterization, and Catalytic Performance in Esterification

Functionalized ionic liquid samples (bmim-PW12) were synthesized by 1-butyl-3-methyl-imidazolium bromide (bmimBr) and 12-phosphotungstic heteropolyacid (PW12). The samples were annealed at 100–450°C and were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, thermal gravity-DTG, brunauer emmett teller, and NH3-temperature programmed desorption. The results showed that the bmim-PW12 samples were crystal and maintained intact Keggin structure. The organic parts of those samples were partly decomposed at a temperature more than 350°C. The sample annealed at 400°C exhibited nano-porous structure, strong acidity, and excellent catalytic activity on the esterification of n-butanol with acetic acid. The higher ester yield was obtained when the mass ratio of catalyst over the reactants amount was 5% for bmim-PW12 catalyst annealed at 400°C.

Plastic catalytic pyrolysis to fuels as tertiary polymer recycling method: Effect of process conditions

This paper presents results regarding the effect of various process conditions on the performance of a zeolite catalyst in pyrolysis of high density polyethylene. The results show that polymer catalytic degradation can be operated at relatively low catalyst content reducing the cost of a potential industrial process. As the polymer to catalyst mass ratio increases, the system becomes less active, but high temperatures compensate for this activity loss resulting in high conversion values at usual batch times and even higher yields of liquid products due to less overcracking. The results also show that high flow rate of carrier gas causes evaporation of liquid products falsifying results, as it was obvious from liquid yield results at different reaction times as well as the corresponding boiling point distributions. Furthermore, results are presented regarding temperature effects on liquid selectivity. Similar values resulted from different final reactor temperatures, which are attributed to the batch operation of the experimental equipment. Since polymer and catalyst both undergo the same temperature profile, which is the same up to a specific time independent of the final temperature. Obviously, this common temperature step determines the selectivity to specific products. However, selectivity to specific products is affected by the temperature, as shown in the corresponding boiling point distributions, with higher temperatures showing an increased selectivity to middle boiling point components (C8-C9) and lower temperatures increased selectivity to heavy components (C14-C18).

Sodium phosphate as a solid catalyst for biodiesel preparation

Sodium phosphate (Na3PO4) was chosen as catalyst for biodiesel preparation from rapeseed oil. The effects of mass ratio of catalyst to oil, molar ratio of methanol to oil, reaction temperature and rotation speed on biodiesel yield were investigated. For a mass ratio of catalyst to oil of 3%, molar ratio of methanol to oil of 9:1, reaction temperature of 343K and rotation speed of 600rpm, the transesterification was nearly completed within 20 minutes. Na3PO4 has a similar activity to homogeneous catalysts. Na3PO4 could be used repeatedly for 8 runs without any activation treatment and no obvious activity loss was observed. The concentrations of catalyst in biodiesel ranged from 0.6 to 0.7 mg/g. Compared to Na3PO4, Na3PO4.10H2O was cheaper, but the final yield was 71.3%, much lower than that of Na3PO4 at 99.7%.

H-ZSM-11 and Zn-ZSM-11 zeolites and their applications in the catalytic transformation of LDPE

Low density polyethylene was converted into hydrocarbons over Zn- and H-ZSM-11 zeolite catalysts in a fixed-bed reactor during 20 and 60 min reaction time, 0.5 and 2.0 polymer to catalyst mass ratio at 500 °C. The zeolites were synthesized by conventional techniques and characterized by XRD, pyridine FTIR and N 2 adsorption. The adsorbed pyridine spectra demonstrated that new Lewis sites were formed after Zn exchange, and that the relationship between Lewis and Brönsted sites in the Zn-ZSM-11 zeolite (3.53) was much higher than that in the H-ZSM-11 zeolite (0.09). Thermal analyses confirmed that the temperature of decomposition of the polymer can be decreased in as much as about 145 °C when the catalysts were added. As compared to the thermal degradation, the catalytic conversion produced less solid residues and much higher amounts of gas and liquid hydrocarbons. The catalysts showed different yield profiles: the H-ZSM-11 zeolite yielded more gases, while the Zn-ZSM-11 zeolite yielded more liquid products. Notably over Zn-ZSM-11 zeolite, these liquid products were mainly aromatic, and depending on experimental conditions (higher temperature, longer reaction time, smaller polymer/catalyst relationship), aromatic selectivity could be increased to almost 100%.

Transesterification of Vegetable Oils with Ethanol and Characterization of the Key Fuel Properties of Ethyl Esters

The transesterification reactions of four different vegetable oils (sunflower, rapeseed, olive oil and used frying oil) with ethanol, using sodium hydroxide as catalyst, were studied. The ester preparation involved a two-step transesterification reaction, followed by purification. The effects of the mass ratio of catalyst to oil (0.25 – 1.5%), the molar ratio of ethanol to oil (6:1 – 12:1), and the reaction temperature (35 – 90 °C) were studied for the conversion of sunflower oil to optimize the reaction conditions in both stages. The rest of the vegetable oils were converted to ethyl esters under optimum reaction parameters. The optimal conditions for first stage transesterification were an ethanol/oil molar ratio of 12:1, NaOH amount (1% wt/wt), and 80 °C temperature, whereas the maximum yield of ethyl esters reached 81.4% wt/wt. In the second stage, the yield of ethyl esters was improved by 16% in relation with the one-stage transesterification, which was obtained under the following optimal conditions: catalyst concentration 0.75% and ethanol/oil molar ratio 6:1. The fuel properties of the esters were measured according to EN test methods. Based on the experimental results one can see that the ethyl esters do not differ significantly from methyl esters. Moreover, the results showed that the values of density, viscosity, and higher heating value of ethyl esters were similar to those of automotive and heavy duty engine diesel fuel. However, the CFPP values were higher, which may contribute to potential difficulties in cold starts. On the other hand, the flash points, which were higher than those of diesel fuel constituted a safety guarantee from the point of view of handling and storage.

Oil transesterification over calcium oxides modified with lanthanum

Investigations were conducted on a series of calcium and lanthanum oxides catalyst for biodiesel production. Mixed oxides catalyst showed a superior transesterification activity over pure calcium or pure lanthanum oxide catalysts. The catalyst activity was correlated with surface basicity and specific surface areas. The effects of water and free fatty acids (FFA) levels in oil feedstock, water and CO 2 in air, mass ratio of catalyst, molar ratio of oil to methanol, and reaction temperature on fatty acid methyl ester (FAME) yield were investigated. Under optimal conditions, FAME yields reached 94.3% within 60 min at 58 °C. Mixed CaO-La 2O 3 catalyst showed a high tolerance to water and FFA, and could be used for converting pure or diluted unrefined/waste oils to biodiesel.

Liquid phase selective oxidation of diphenylmethane to benzophenone over ternary hydrotalcites with tert-butylhydroperoxide

Abstract Selective oxidation of diphenylmethane to benzophenone was carried out over M–MgAl ternary hydrotalcites, where M is Cu, Co or Fe, using tert -butylhydroperoxide (TBHP) as an oxidant. Influence of various reaction parameters, such as reaction temperature, reaction time, substrate: catalyst mass ratio, substrate: oxidant mole ratio and nature of solvent on the activity and selectivity for the desired reaction were evaluated. Among the catalysts studied CuMgAl-13 showed a maximum diphenylmethane conversion of 95% with 100% selectivity towards benzophenone, at 65 o C/24 h with TBHP as an oxidant and acetonitrile as a solvent. Redox metal species present in the hydrotalcite structure were thought to be the active centers involved and a reaction mechanism involving free radicals was proposed.

Synthesis, characterization and catalytic application of H3PW12O40/MCM-48 in the esterification of methacrylic acid with n-butyl alcohol

A novel environmental friendly catalyst, H3PW12O40/MCM-48, was prepared by impregnation method. The catalysts were characterized by means of XRD and FT-IR. The synthesis of n-butyl methacrylate catalyzed by H3PW12O40/MCM-48 was studied with methacrylic acid and n-butyl alcohol as reactants. H3PW12O40/MCM-48 is an excellent catalyst for synthesizing n-butyl methacrylate and Keggin structure of H3PW12O40 kept unchanged after being impregnated on surface of the molecular sieve support. Effects of n(methacrylic acid):n(n-butyl alcohol), catalyst dosage, cyclohexane(water-stripped reagent) and reaction time on yields of the product were investigated. The optimum conditions have been found, that is, molar ratio of acid to alcohol is 1:1.6, mass ratio of catalyst used to the reactants is 0.5% and reaction time is 2.0 h. Under these conditions, the yield of n-butyl methacrylate can reach 93.7%.

Visbreaking of heavy petroleum oil catalyzed by SO 4 2− /ZrO2 solid super-acid doped with Ni2+ or Sn2+

SO 4 2− /ZrO2 solid super-acid catalysts (SZ) doped with Ni2+ or Sn2+ (Ni2+/SZ, Sn2+/SZ) were prepared for catalytic visbreaking of heavy petroleum oil from Shengli oil field. The visbreaking reactions were carried out at 240°C and 3–4 MPa for 24 h using a heavy petroleum oil to catalyst mass ratio of 100 : 0.05. The effect of water content on viscosity of heavy petroleum oil was also investigated. Both catalysts can promote thermolysis of heavy petroleum oil and the viscosity was reduced from 0.319 Pa·s to 0.135 Pa·s for Ni2+/SZ and 0.163 Pa·s for (Sn2+/SZ) with visbreaking rates of 57.7% and 48.9%, respectively. After visbreaking, the saturated hydrocarbon content increased while aromatics, resin, asphaltene, sulfur and nitrogen content decreased. The presence of water was disadvantageous to visbreaking of heavy petroleum oil.

Direct esterification of cinnamic acids with phenols and imidoalcohols: A simple heteropolyacid-catalyzed procedure

A convenient procedure for the direct esterification of cinnamic acids with phenols or 2-(Nphthalimido)ethanol is described. The method is simple and clean, environmentally friendly and high-yielding for both electron-releasing and electron-withdrawing substituted phenols. The heteropolyacid H6P2W18O62·24 H2O was employed as catalyst, both bulk and supported on silica. No stoichiometric activation of the carboxyl group or condensing reagents is necessary. The effects of temperature, reaction time, amount of the catalyst used and mole ratio of the reactants on the ester yield were checked. Suitable conditions for the reaction include a 1:1 molar ratio of reactants and a 1 mmol % mass ratio of catalyst to reactant. Eighteen aryl and phthalimidoethyl cinnamates were obtained, yields ranged in 84-95% for most of the esters. The catalyst shown to be reusable for at least three times without occurring an appreciable loss of its activity.

Study on reformulation of fluid catalytic cracking gasoline and increasing production of light olefins

The effects of reaction temperature, mass ratio of catalyst to oil, space velocity, and mass ratio of water to oil on the product distribution, the yields of light olefins (light olefins including ethylene, propylene and butylene) and the composition of the fluid catalytic cracking (FCC) gasoline upgraded over the self-made catalyst GL in a confined fluidized bed reactor were investigated. The experimental results showed that FCC gasoline was obviously reformulated under appropriate reaction conditions. The olefins (olefins with C atom number above 4) content of FCC gasoline was markedly reduced, and the aromatics content and octane number were increased. The upgraded gasoline met the new standard of gasoline, and meanwhile, higher yields of light olefins were obtained. Furthermore, higher reaction temperature, higher mass ratio of catalyst to oil, higher mass ratio of water to oil, and lower space velocity were found to be beneficial to FCC gasoline reformulation and light olefins production.

Optimization of Crotonaldehyde Oxidation Catalyst using Response Surface Methodology

AbstractCrotonic acid was produced by oxidation of crotonaldehyde over molybdophosphoric acid supported on activated carbon. The full 23 central composite design was performed and aimed at optimizing oxidation catalysts to maximize the yield of crotonic acid. Response surface methodology was applied to obtain a second‐order polynomial model and to generate the optimum conditions, with a loading of molybdophosphoric acid of 0.25, mass ratio of catalyst to crotonaldehyde of 0.025 and mass ratio of vanadium pentoxide to molybdophosphoric acid of 0.08. The crotonic acid yield was 66.7 % under these conditions. Three experiments were conducted using the same optimum conditions, and therefore, good agreement was observed between the experimental data and the predicted values obtained from the model, by comparison

Calcium Ethoxide as a Solid Base Catalyst for the Transesterification of Soybean Oil to Biodiesel

In this work, calcium ethoxide is proposed as a catalyst for the transesterification of soybean oil to biodiesel with methanol and ethanol. First, calcium ethoxide was synthesized through a calcium reaction with ethanol. Then, its physical and chemical characteristics were determined using instrumental methods such as Brunauer−Emmett−Teller surface area measurements, scanning electron micrographs, and particle size distribution measurements. The effects of the mass ratio of catalyst to oil, the molar ratio of methanol to oil, and the reaction temperature were studied to optimize the reaction conditions. The experimental results showed that the optimum conditions are a 12:1 molar ratio of methanol to oil, the addition of 3% Ca(OCH2CH3)2 catalyst, and a 65 °C reaction temperature. A 95.0% biodiesel yield was obtained within 1.5 h in these conditions, and the activation energy was 54 149 J/mol. It also indicated that the catalysis performance of calcium ethoxide is better than that of CaO. Besides, a 91.8% b...

Recovery of polyols from flexible polyurethane foam by “split-phase” glycolysis: Study on the influence of reaction parameters

The general purpose of polyurethane chemical recycling is to recover constituent polyol, a valuable raw material. Among suitable processes, glycolysis, especially in two phases, allows better quality products. Potassium octoate a compound derived from cycloaliphatic carboxylic acids shows suitable catalytic activity. A detailed study of the main reaction parameters affecting the reaction and properties of the recovered polyol has been carried out. They include carboxylate catalyst concentration, reaction temperature and mass ratio of treated foam to the glycolysis agent. An increase in the reaction temperature and catalyst concentration enhances the degradation rate, however, it also affects the process negatively by promotion of secondary reactions and contamination of the polyol phase. Related to the glycolysis agent amount, the minimum quantity required to split the phases has been determined, as well as the optimal ratio.

Calcium methoxide as a solid base catalyst for the transesterification of soybean oil to biodiesel with methanol

In this study, physical and chemical characterizations of calcium methoxide were investigated to assess its performance as an excellent solid base catalyst using some instrumental methods, such as BET surface area measurement, scanning electron micrographs and particle size distribution. Then, it was used to catalyze transesterification of soybean oil to biodiesel with methanol. The effects of various factors such as mass ratio of catalyst to oil, reaction temperature and volume ratio of methanol to oil were studied to optimize the reaction conditions. The results showed that calcium methoxide has strong basicity and high catalytic activity as a heterogeneous solid base catalyst and it was obtained a 98% biodiesel yield within 2 h in this reaction. Besides, the recycling experiment results showed it had a long catalyst lifetime and could maintain activity even after being reused for 20 cycles.

Aromatization Reactions of Three Gasoline Fractions

Using a confined fluidized bed reactor and aromatization catalysts (LBO-A and LBO-16), three fluid catalytic cracking (FCC) narrow fraction gasoline (Lanlian gasoline, Shandong gasoline, and Fushun gasoline) at 420°C has been studied. The results reveal that at 420°C and a mass ratio of catalyst to oil of 5, the olefin content is remarkably reduced from about 20 to 30% (by mass) over 75% LBO-A and 25% LBO-16, and the octane number is kept at a high level after the aromatization reaction, at the same time the nine lumps model of aromatization reaction is put forward based on the corresponding mechanism. The method obtained can provide the technical instruction for the petroleum chemical plant.

Transesterification of soybean oil to biodiesel using CaO as a solid base catalyst

In this study, transesterification of soybean oil to biodiesel using CaO as a solid base catalyst was studied. The reaction mechanism was proposed and the separate effects of the molar ratio of methanol to oil, reaction temperature, mass ratio of catalyst to oil and water content were investigated. The experimental results showed that a 12:1 molar ratio of methanol to oil, addition of 8% CaO catalyst, 65 °C reaction temperature and 2.03% water content in methanol gave the best results, and the biodiesel yield exceeded 95% at 3 h. The catalyst lifetime was longer than that of calcined K 2CO 3/γ-Al 2O 3 and KF/γ-Al 2O 3 catalysts. CaO maintained sustained activity even after being repeatedly used for 20 cycles and the biodiesel yield at 1.5 h was not affected much in the repeated experiments.

Catalytic oxidation of isophorone to ketoisophorone over ruthenium supported MgAl-hydrotalcite

Abstract Selective oxidation of α-isophorone to ketoisophorone was carried out over Ruthenium supported MgAl-hydrotalcite in the temperature range 40–100 °C using acetonitrile as a solvent and tert -butyl hydroperoxide as an oxidant. The influence of various reaction parameters, such as reaction temperature, reaction time, substrate: catalyst mass ratio, substrate:oxidant mole ratio, and nature of solvent was studied. A maximum conversion of 60% KIP with 100% selectivity in 48 h was observed with a substrate: catalyst mass ratio of 10:1 at 60 °C.

Transesterification of soybean oil to biodiesel using SrO as a solid base catalyst

Abstract In this study, transesterification of soybean oil to biodiesel using SrO as a solid base catalyst was studied. The reaction mechanism was proposed and the separate effects of reaction temperature, molar ratio of methanol to oil, mass ratio of catalyst to oil and repeated experiments were investigated. The results showed that the yield of biodiesel produced with SrO as a catalyst was in excess of 95% at temperatures below 70 °C within 30 min. SrO had a long catalyst lifetime and could maintain sustained activity even after being repeatedly used for 10 cycles. The results proved that transesterification of soybean oil to biodiesel using SrO as a catalyst is a commercially viable way to decrease the costs of biodiesel production.