Ethyl acetate (systematically, ethyl ethanoate, commonly abbreviated EtOAc or EA) is the organic compound with the formula CH3COOCH2CH3. This colorless liquid has a characteristic, pungent smell (similar to pear drops) like certain glues or nail polish removers, in which it is used. Ethyl acetate is the ester from ethanol and acetic acid; it is manufactured on a large scale for use as a solvent.
It can also be prepared through Tishchenko reaction, by combining two equivalents of acetaldehyde in the presence of an alkoxide base as catalyst. This way is a commercial method of producing ethyl acetate.
Catalysts for dehydrogenation include copper, operating at an elevated temperature but below 250 °C. The copper may have its surface area increased by depositing it on zinc, promoting the growth of snowflake, fractal like, structures. This surface area can be again increased by deposition onto a zeolite, typically ZSM-5. Traces of rare earth metals or alkalies, such as that of sodium and potassium, have also been found to be beneficial to the process. Byproducts of hydrogenation include diethyl ether (thought to primarily arise due to aluminum sites in the catalyst), acetaldehyde, acetaldehyde aldol products, higher esters and ketones. Acetaldehyde and MEK complicate conversion and purification as ethanol forms an azeotrope with water, as does ethyl acetate with ethanol and water and MEK with both ethanol and the acetate. To obtain a high purity product, these azeotropes must be "broken", and this can be achieved by making use of pressure swing distillation.
The composition of the distillate removed from the conversion products is biased towards acetate at atmospheric pressure and ethanol at increased pressure. First, the raw product is fed into a high pressure column where the bulk of the contaminating ethanol is removed. By then feeding the ethanol depleted distillate into a low pressure column, the acetate can be removed from the remaining ethanol azeotrope.
MEK forms during the conversion process from 2-butanol. The latter fails to form an azeotrope with the acetate and so MEK can be removed by hydrogenation of the contaminated product over nickel and further distillation to strip away 2-butanol. This provides the simultaneous benefit of removing the acetylaldehyde contaminant by returning it to an ethanol form and is easily accomplished as hydrogen is a byproduct of the initial dehydrogenation process.
It may also be possible to break the azeotropes with the use of membrane distillation, molecular sieves, an entrainer or absorption medium.
The distilled ethanol and rehydrogenated contaminants can then be recycled into the raw feedstock.
In the laboratory, mixtures of ethyl acetate and other solvents are commonly used in chromatography. It is also used as a solvent for extractions. Ethylacetate is rarely selected as a reaction solvent because it is prone to hydrolysis.
Like most simple esters, ethyl acetate has a fruity smell. Ethyl acetate is present in confectionery, perfumes, and fruits. In perfumes, it evaporates quickly, leaving but the scent of the perfume on the skin.
To obtain high yields, it is preferable to use a stoichiometric amount of strong base, such as sodium hydroxide. This reaction gives ethanol and sodium acetate, which is not able to react with ethanol any longer:
Some industrial plants use Ethylene----> Acetic Acid in the presence of an tungstasilic acid on a silica support. This is the catalyst and the Exothermic reaction is cooled by water/ethanol/acetic acid.
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