Sulfuric acid ethylene glycol production

Chlorinated Ethers. Ethylene chlorohydrin reacts with sulfuric acid to form f./T-dichloroethyl ether. It is u byproduct of ethylene glycol production. The chlorines on this ether are inert, making it a good solvent. Further chlorination at 20-30 C gives diethyl ether which hydrolyzes to chloroacclaldehyde and ethylene chlorohydrin. Ethylene and sulfur monochloride react to give /J./i -dichlorodiethyl sulfide (mustard gas), which Is a thioelher. 

Add hydrolysis is usually carried out with sulfuric acid. The reaction products are ethylene glycol and terephthalic acid (Scheme 4.10). 

The phthalic acid and benzoic acid are reacted to form a reaction intermediate. The reaction intermediate is dissolved in sulfuric acid, which precipitates terephthalic acid (TPA). Fifty percent of the TPA is sold as a product and 50 percent is further processed at your facility into polyester fiber. The TPA Is treated with ethylene glycol to form an intermediate product, which is condensed to polyester. 

In a continuous process, ground PET bottles (830 parts) in an aqueous slurry were pumped into an autoclave equipped with a stirrer and maintained at 450-550 psig pressure and 191-232°C. Ammonium hydroxide (300 parts) solution consisting of water (7857 parts), ethylene glycol (493 parts), and ammonium sulfate (918 parts) was introduced into the reactor. The retention time in the reactor varied from 5 to 45 min. The aqueous diammonium terephthalate and edtylene glycol solution was withdrawn from the reactor and filtered while hot to remove solid impurities such as pigments, pieces of metal caps, labels, and cap liners. Hie filtrate was acidified widi sulfuric acid solution to liberate the TPA product. Hie recovered TPA usually had a purity of 99% or higher. 

KOMAROWSKY REACTION. The reaction between certain alcohols and p-hytlroxybenzaldehyde in dilute sulfuric acid solutions to give soluble colored complexes. 1.2-Propylene glycol gives a colored product while ethylene glycol does not. The reaction has also hecn employed to determine eychthexanol in cyclohexanone. 

The reaction chemistry of simple organic molecules in supercritical (SC) water can be described by heterolytic (ionic) mechanisms when the ion product 1 of the SC water exceeds 10" and by homolytic (free radical) mechanisms when <<10 1 . For example, in SC water with Kw>10-11 ethanol undergoes rapid dehydration to ethylene in the presence of dilute Arrhenius acids, such as 0.01M sulfuric acid and 1.0M acetic acid. Similarly, 1,3 dioxolane undergoes very rapid and selective hydration in SC water, producing ethylene glycol and formaldehyde without catalysts. In SC methanol the decomposition of 1,3 dioxolane yields 2 methoxyethanol, il lustrating the role of the solvent medium in the heterolytic reaction mechanism. Under conditions where K klO"11 the dehydration of ethanol to ethylene is not catalyzed by Arrhenius acids. Instead, the decomposition products include a variety of hydrocarbons and carbon oxides. 

The transformation of raw materials into products of greater value by means chemical reaction is a major industry, and a vast number of commercial prod is obtained by chemical synthesis. Sulfuric acid, ammonia, ethylene, propyl phosphoric acid, chlorine, nitric acid, urea, benzene, methanol, ethanol, ethylene glycol are examples of chemicals produced in the United States, billions of kilograms each year. These in turn are used in the large-scale manu ture of fibers, paints, detergents, plastics, rubber, fertilizers, insecticides, Clearly, the chemical engineer must be familiar with chemical-reactor design operation. 

Procedure Place 200 grams of ethylene glycol and 6.4 grams of 98% sulfuric acid into a distillation apparatus, and then distill the mixture at 110 Celsius for 6 hours. During the 6 hours, a distillate containing dioxane, water, and by-products will be obtained in the receiver flask. After the 6 hours, pour the liquid in the receiver flask into a clean beaker, and then add 120 grams of anhydrous calcium chloride. Then thoroughly blend the mixture for 2 hours. After 2 hours, filter-off the calcium chloride, and then place the filtered mixture into a clean distillation apparatus. Then distill at 101 Celsius for 6 hours. After 6 hours, the liquid in the receiver flask will be composed of about 98% dioxane. 

For separation of the olefins, reliance was placed largely on efficient fractional distillation under pressure, using techniques now familiar to the petroleum industry the unusual feature was the low temperature required for concentration of ethylene. The main olefin reactions developed were hydration with sulfuric acid to give the alcohol, which was then dehydrogenated to the corresponding aldehyde or ketone, and conversion to the olefin oxide by reaction with hypochlorous acid. The ready commercial availability of the olefin oxides led to a continuous stream of new products, such as glycols, glycol ethers, and alkanolamines. 

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