Esterification

Aslam, Mohammad; Torrence, G. Paull; Zey, Edward G.

doi:10.1002/0471238961.0519200501191201.a01

Cited by 4 publications

(5 citation statements)

References 57 publications

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“…The solvents were evaporated under reduced pressure at 40 uC and a white powder was obtained. Because the rate of esterification is enhanced in excess alcohol, 29 1-pentanol was used in an excess of a factor of 20 with regard to the zinc salt.…”

Section: Experimental Synthesis Of Zno Nanoparticlesmentioning

confidence: 99%

Precipitation of monodisperse ZnO nanocrystals via acid-catalyzed esterification of zinc acetate

et al. 2006

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A wet-chemical method to produce zinc oxide nanocrystals of monodisperse size distribution (diameter range of 20-80 nm) is presented. The synthesis starts from zinc acetate dihydrate which is converted to ZnO in the presence of 1-pentanol in m-xylene at 130 uC. We report for the first time catalysis of this reaction by p-toluene sulfonic acid monohydrate (p-TSA), which allows a shorter reaction time and improves both the reproducibility of the particle size distribution and the crystallinity of the particles. The reaction can be scaled up to give multigram quantities of product per batch. Particles were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and photoluminesence (PL) spectroscopy. Room temperature PL spectra of ZnO prepared without catalyst exhibit a strong and sharp UV emission band at ca. 385 nm and a weak and very broad green-yellow visible emission centered at ca. 550-560 nm. However, for nanoparticles precipitated in the presence of p-TSA, the UV emission is enhanced by a factor of 4, which can be correlated with the improvement of crystal perfection. A particle formation mechanism is discussed.

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Section: Experimental Synthesis Of Zno Nanoparticlesmentioning

confidence: 99%

Precipitation of monodisperse ZnO nanocrystals via acid-catalyzed esterification of zinc acetate

et al. 2006

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“…Regarding the kinetics, the presence of a catalyst (typically an acid) is preferable because auto-catalysed reactions through the autoprotolysis reaction of the organic acid are slow and thus not always adequate for industrial purposes (Aslam et al, 2010). Homogeneous mineral acids (sulfuric acid, hydrochloric acid) efficiently promote direct esterification and are therefore typically used in industrial contexts.…”

Section: Introductionmentioning

confidence: 99%

“…There is only a partial conversion of acids to the relevant esters, and the recovery of pure products in an industrial context is complicated by the coexistence of unreacted acids, ethyl esters, water and ethanol in the crude homogeneous reaction mixture, which requires several further expensive unit operations for purification (Aslam et al, 2010). To simplify the recoverability of the products and to promote equilibrium versus higher conversion, the typically adopted approach consists of removing water from the reactive environment in agreement with the principles of process intensification (Stankiewicz and Moulijn, 2000).…”

Section: Introductionmentioning

confidence: 99%

Process intensification for the production of the ethyl esters of volatile fatty acids using aluminium chloride hexahydrate as a catalyst

Bitonto

Menegatti

Pastore

2019

Journal of Cleaner Production

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A new process for obtaining the ethyl esters of volatile fatty acids with ethanol by using aluminium chloride hexahydrate as a catalyst is proposed. Aluminium chloride not only exhibits good activity, composition equilibrium is achieved within 3e4 h at 343 K, but also induces a phase separation with a convenient distribution of the components. In fact, more than 99 %wt of the ethyl esters, together with most of the unreacted acid and ethanol, were found in the upper layer, which was well separated from the bottom phase, which contained the co-formed water and over 97.8 %wt of the catalyst. The intensification of this reaction and separation was thoroughly investigated and the operational conditions optimised. The effects of this separation on the purification of the final ethyl esters is fully investigated. A new configuration of unit operations is designed for the specific production of ethyl acetate, simulated through Aspen Plus V9® and compared with the current industrial process based on sulfuric acid catalysis. The overall production and purification of ethyl acetate is economically competitive, reduces the energy requirements by more than 50%, and is potentially a zero-waste process, resulting in cleaner production.

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“…139 Th ere are also studies on vapor-phase esterifi cation, including in a supercritical CO 2 atmosphere, but they are not commercially viable. 139,141,142 Hydrogenation (hydrogenolysis) of methyl or ethyl acetate is carried out with heterogeneous catalysts in fi xed-bed reactors. Various catalysts have been used for both reactions but at reaction conditions.…”

Section: Methanol To Ethanol Via Acetic Acid Esterifi Cationmentioning

confidence: 99%

“…137,138 Esterifi cation of ethanol and acetic acid is also an equilibrium-limited reaction, but in this case, a ternary azeotrope is present. 101,139 Industrial production of ethyl acetate can be conducted in batch or CSTR reactors along with several distillation columns. 140 Th e same considerations as in the esterifi cation with methanol are applicable (depending on the syngas composition and plant confi guration) normally leads to a net production of H 2 .…”

Section: Methanol To Ethanol Via Acetic Acid Esterifi Cationmentioning

confidence: 99%

Potential routes for thermochemical biorefineries

Haro

Ollero

Perales

et al. 2013

Biofuels Bioprod Bioref

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This critical review focuses on potential routes for the multi-production of chemicals and fuels in the framework of thermochemical biorefineries. The up-to-date research and development in this field has been limited to BTL/G (biomass-to-liquids/gases) studies, where biomass-derived synthesis gas (syngas) is converted into a single product with/without the co-production of electricity and heat. Simultaneously, the interest on biorefineries is growing but mostly refers to the biochemical processing of biomass. However, thermochemical biorefineries (multi-product plants using thermo-chemical processing of biomass) are still the subject of few studies. This scarcity of studies could be attributed to the limitations of current designs of BTL/G for multi-production and the limited number of considered routes for syngas conversion. The use of a platform chemical (an intermediate) brings new opportunities to the design of process concepts, since unlike BTL/G processes they are not restricted to the conversion of syngas in a single-reaction system.Most of the routes presented here are based on old-fashioned and new routes for the processing of coaland natural-gas-derived syngas, but they have been re-thought for the use of biomass and the multiproduction plants (thermochemical biorefinery). The considered platform chemicals are methanol, DME, and ethanol, which are the common products from syngas in BTL/G studies. Important keys are given for the integration of reviewed routes into the design of thermochemical biorefineries, in particular for the selection of the mix of co-products, as well as for the sustainability (co-feeding, CO2 capture, and negative emissions).

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Esterification

Cited by 4 publications

References 57 publications

Precipitation of monodisperse ZnO nanocrystals via acid-catalyzed esterification of zinc acetate

Precipitation of monodisperse ZnO nanocrystals via acid-catalyzed esterification of zinc acetate

Process intensification for the production of the ethyl esters of volatile fatty acids using aluminium chloride hexahydrate as a catalyst

Potential routes for thermochemical biorefineries

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