The Acid Catalyzed Reaction of α-Pinene Over Y-Zeolite (original) (raw)

Synthesis of Terpineol from Α-Pinene Catalyzed by Tca/Y-Zeolite

Indonesian Journal of Chemistry, 2011

The hydration of -pinene has been studied in the presence of TCA/Y-Zeolite catalyse. The catalyst was prepared by impregnating trichloroacetic acid (TCA) on support of Y-Zeolite. The TCA/Y-Zeolite catalyst converted -pinene into hydrocarbons, while the TCA/Y-Zeolite catalyst was active and selective for producing alcohols, with a conversion of 66% and showed 55% selectivity for -terpineol at 10 min. The reaction taken place in a solid-liquid mode and most of the -terpineol is extracted out by the organic phase during the course of the reaction. TCA/Y-Zeolite was found as good catalyst for hydration of -pinene to produce -terpineol.

Acetoxylation and hydration of limonene and α-pinene using cation-exchanged zeolite beta

Journal of Molecular Catalysis A-chemical, 2009

Hydration and acetoxylation of limonene and ␣-pinene into terpineol and terpinyl acetate in the liquid phase have been studied using transition metal and rare earth ion-exchanged beta zeolite. These catalysts under optimized reaction conditions showed higher activity and selectivity compared to conventionally used acid catalysts such as H 2 SO 4 and amberlyst-15. Conversions of 9-26% and 58-82% were obtained for limonene the in presence of glacial and aqueous acetic acid, respectively, and the selectivity for major products ␣-terpinyl acetate and terpineol were up to 54% and 65%, respectively. Conversion values in the range of 62-100% and 72-100% were obtained for ␣-pinene in the presence of glacial and aqueous acetic acid, respectively. Virtually no oligomerisation of monoterpenes occurred under studied conditions. From the measured acidity data of these zeolites, it is observed that both hydration and acetoxylation are Brönsted acid-catalysed reactions.

Isomerization of Alpha-pinene Over Acid Treated Natural Zeolite

Chemical Engineering Communications, 2005

In this study, isomerization of a-pinene was studied over several acid-treated natural zeolite catalysts rich in clinoptilolite. Zeolite samples were contacted with HCl at different concentrations at 30 C or at 60 C for 3 and 24 hours and tested in isomerization reaction of alpha-pinene. The catalysts prepared were characterized by XRD, nitrogen adsorption, and acidity studies. Acidity strength and the distribution of Lewis and Brö nsted acid sites of the catalysts were determined, and their catalytic activities in a-pinene isomerization and selectivities to main reaction products, camphene and limonene, were investigated. Acid treatment improved the selectivity of catalyst samples to camphene, decreasing the selectivity to limonene, probably forcing limonene to secondary reactions at high conversions. The kinetics of a-pinene consumption was described by first-order kinetics. Two kinetic models were tested for the reaction mechanism and one model was found to give a good correlation between the theoretical and experimental data. In the models, the key intermediate was the pinylcarbonium ion, which was formed irreversibly from a-pinene. Number and distribution of Lewis and Brö nsted acid sites affect the formation of bicyclic and monocyclic products.

Study of homogeneous acid catalysis for the hydration of α-Pinene

2012

th October, 2012 Homogenous acid was used as catalyst for the hydration of α-pinene using water as hydroxyl donor, which is soluble in aqueous and organic solvents. -pinene is the main component of most turpentine oils. In order to obtain more valuable products, α-pinene in the turpentine can be hydrated in dilute mineral acid solutions to produce α- terpineol, which can be used as perfume, repellent of insect, antifungal and disinfectant. The Highest selectivity of terpineol was 74% with a convertion of 88% after 30 min of reaction at 70 o C.

Acetoxylation and hydration of limonene and [alpha]-pinene using cation-exchanged zeolite beta

Journal of Molecular Catalysis A: …, 2009

Hydration and acetoxylation of limonene and α-pinene into terpineol and terpinyl acetate in the liquid phase have been studied using transition metal and rare earth ion-exchanged beta zeolite. These catalysts under optimized reaction conditions showed higher activity and selectivity compared to conventionally used acid catalysts such as H2SO4 and amberlyst-15. Conversions of 9–26% and 58–82% were obtained for limonene the

Isomerization of α-pinene over calcined natural zeolites

Applied Catalysis A: General, 2004

In this work, isomerization reaction of ␣-pinene was studied over several heat-treated natural zeolite catalysts, rich in clinoptilolite, from Balýkesir-Bigadic region in Turkey in a batch slurry reactor under nitrogen atmosphere. Zeolite samples were calcined at different temperatures such as 300, 450 and 600 • C. All catalysts were tested in the isomerization reaction of ␣-pinene and were characterised by nitrogen adsorption experiments, IR, and XRD measurements. Acidity strength and the distribution of Lewis and Bronsted acid sites of the samples were determined. Selectivities to main reaction products, camphene and limonene, and reaction kinetics were investigated. Catalytic activity, that is total conversion of ␣-pinene, of heat-treated samples decreased with increasing calcination temperatures. Selectivity to limonene is dependent on ␣-pinene conversion at high conversion levels while the selectivity to camphene is not. The formation of heavy products increased with treatment temperature. It was seen that ␣-pinene consumption could be described by a first-order kinetics.

Kinetics Modeling of Hydration α-Pinene to α-Terpineol Using Solid Catalyst

α-Pinene is the main component of the most turpentine oils. The hydration of α-pinene with acid catalysts leads to a complex mixture of monoterpenes. By controlling the reaction variables it is possible to make the reaction highly selective towards the desired products, namely α-terpineol. The data on synthesis of α-terpineol from α-pinene in the presence of different catalysts have been studied. The hydration of α-pinene can also be accomplished with catalyst of zeolite H-beta.

Heterogeneous Zeolite-Based Catalyst for Esterification of α-Pinene to α-Terpinyl Acetate

Oriental Journal of Chemistry

The purpose of this study is to determine the most effective type of heterogeneous catalyst such as natural zeolite (ZA), Zr-natural zeolite (Zr/ZA) and zeolite Y (H/ZY) in esterification of α-pinene. α-terpinyl acetate was successfully synthesized from α-pinene and acetic anhydride by their heterogeneous catalysts. The esterification reaction was carried out with reaction time, temperature and zeolite catalysts. The most effective catalysts used in the synthesis of α-terpinyl acetate is catalyst H/ZY with the yield is 52.83% at 40 o C for the time 4 h with a selectivity of 61.38%. The results showed that the effective separation of catalyst could contribute to developing a new strategy for the synthesis of α-terpinyl acetate.

Synthesis of terpineol from α-pinene by homogeneous acid catalysis

Catalysis Today, 2005

Chloroacetic acid was used as catalyst for the hydration of a-pinene using water as hydroxyl donor, which is soluble in aqueous and organic solvents. The highest selectivity was 95.5 with a conversion of 10%, whereas the higher conversion was 99% with selectivity of 70% after 4 h of reaction at 70 8C. Organo-chlorinated compounds were not found in products as in the case of the use of HCl as catalyst, which indicates that the intermediate carbocation formed after alkene protonation is not susceptible to react with the chloroacetic anion. #

Isomerisation of α-pinene over Beta zeolites synthesised by different methods

Journal of Molecular Catalysis A: Chemical, 2005

Liquid-phase ␣-pinene isomerisation at l00 • C in a batch reactor is studied over Beta zeolites synthesised by different methods. It is confirmed that ␣-pinene forms a carbenium ion in an acidic environment, which rearranges without capture by nucleophiles, to form mainly hydrocarbons as camphene, terpinenes, terpinolenes and heavy products. The microporous Beta samples show low activity despite the high acidity most probably because of the hindered intermediate formation. The nature of the enhanced activity of Beta mesopores samples is suggested to be a result from the high accessibility of the acidic sites.