Styrene ethylbenzene

Styrene is manufactured from ethylbenzene. Ethylbenzene [100-41-4] is produced by alkylation of benzene with ethylene, except for a very small fraction that is recovered from mixed Cg aromatics by superfractionation. Ethylbenzene and styrene units are almost always installed together with matching capacities because nearly all of the ethylbenzene produced commercially is converted to styrene. Alkylation is exothermic and dehydrogenation is endothermic. In a typical ethylbenzene—styrene complex, energy economy is realized by advantageously integrating the energy flows of the two units. A plant intended to produce ethylbenzene exclusively or mostly for the merchant market is also not considered viable because the merchant market is small and sporadic. 

The ethylene feedstock used in most plants is of high purity and contains 200—2000 ppm of ethane as the only significant impurity. Ethane is inert in the reactor and is rejected from the plant in the vent gas for use as fuel. Dilute gas streams, such as treated fluid-catalytic cracking (FCC) off-gas from refineries with ethylene concentrations as low as 10%, have also been used as the ethylene feedstock. The refinery FCC off-gas, which is otherwise used as fuel, can be an attractive source of ethylene even with the added costs of the treatments needed to remove undesirable impurities such as acetylene and higher olefins. Its use for ethylbenzene production, however, is limited by the quantity available. Only large refineries are capable of deUvering sufficient FCC off-gas to support an ethylbenzene—styrene plant of an economical scale. 

Commercial polystyrenes are normally rather pure polymers. The amount of styrene, ethylbenzene, styrene dimers and trimers, and other hydrocarbons is minimized by effective devolatilization or by the use of chemical initiators (33). Polystyrenes with low overall volatiles content have relatively high heat-deformation temperatures. The very low content of monomer and other solvents, eg, ethylbenzene, in PS is desirable in the packaging of food. The negligible level of extraction of organic materials from PS is of cmcial importance in this appHcation. 

U.S. petroleum benzene prices since 1974 are Hsted in Table 6 (64). Until 1978, benzene prices were relatively stable and through 1985 they increased considerably, peaking in 1981 because of the increased demand for aromatics in the gasoline pool. At that time, there was also a large surplus of low priced imported benzene and a softening of the ethylbenzene—styrene market. The decline of cmde oil prices in 1986 caused a dramatic drop in domestic benzene prices. In 1987, U.S. benzene production increased 13.9% over 1986, and this rise was largely ascribed to a favorable export market for benzene derivatives... 

There are notable cases where plate columns have been converted to packed columns to gain advantage of the low pressure drop exacted from the vapor stream. More recently the packings have been largely of the stmctured type. Illustrative of this is the trend toward the use of stmctured packing in ethylbenzene—styrene fractionators, some of which have diameters of 10 m or higher. 

Billet and cowodcers [Chem. Jng. Tech., 38, 825 (1966) Jnstn. Chem. Engrs. Symp. Set No. 32, 5, 111 (1969] used the ethylbenzene/ styrene system at 100 torr and a 0.8-m column with 500-mm plate spacing. Two weir heights were used, 19 and 38 mm. Operation was at... 

FIG. 14-42 Overall (Murphree) efficiency and pressure drop data for several devices using the same test mixture (ethylbenzene/styrene). See text for details. [Billet, Conrad, and Giuhh, Instn. Chem. Engrs. Symp. Ser. No. 32, 5, 111 (1979).]... 

Failure and Maintenance Data Analysis at a Chemical process Mean-time-between-maintenance action for five Ethylene plant pumps ethylbenzene styrene 46. 

DATA BOUNDARY Ethylene plant pumps ethylbenzene - styrene monomer plant... 

Data from an existing collection system were analyzed for failure modes and distribution. The results of Pareto analyses indicate the principal causes of failure. A few values of mean times to maintenance action (MTBM) are given for ethylene plant pumps (85 electric driven centrifugal pumps over a 19-month period), and ethylbenzene-styrene monomer plant equipment from 10 months data 4 gas compressors, 3 screw conveyors, 121 pumps, and 235 other items... 

CYCLOHEXANE/HEPTANE CYCLOHEXANE/HEPTANE CYCLOHEXANE/heptane CYCLOHEXANE/HEPTANE I SO-OCTANE/TOLUENE ISO-OCTANE/TOLUENE ETHYLBENZENE/STYRENE ISOBUTANE/N-BUTANE ISOBUTANE/N-BUTANE ISOBUTANE/N-BUTANE DEPROPANIZER... 

Ethylbenzene Styrene + Hydrogen The material balance on the flow reactor,... 

Ethylbenzene plants, 23 330-331 Ethylbenzene-styrene complex, 23 328 Ethylbenzene synthesis molecular sieves in, 16 845 zeolite-based alkylation in, 23 331-333 Ethyl benzoate, 3 635 Ethyl P-D-glucopyranoside, 4 701 7-Ethylbicyclooxazolidine, antimicrobial used in cosmetics, 7 831t Ethyl bromide, physical properties of, 4 351t... 

Ethylbenzene Styrene-related perfumes, synthetic polymers, solvents.fax machines, computerterminals and printers,furniture poish, latex and non-latex caulking compounds, floortile adhesives, carpet tile adhesives. 23 Not classified... 

Ethylene dichloride Vinyl chloride Acetic acid Vinyl acetate Ethylbenzene Styrene Ethylene oxide Ethylene glycol... 

Toluene, ethylbenzene, styrene, etc., produce benzoic acid when heated with strong oxidizing agents. 

Ethylbenzene was first produced on a commercial scale in the 1930s in Germany and the United States. The ethylbenzene-styrene industry remained relatively insignificant until the Second World War, when the demand for synthetic styrene-butadiene mbber prompted accelerated teehnology improvements and tremendous capacity expansion (Coty etal., 1987). 

Problem 11.44 Use + and - signs for positive and negative tests in tabulating rapid chemical reactions that an be used to distinguish among the following compounds (a) chlorobenzene, benzyl chloride and cyclohexyl hloride (b) ethylbenzene, styrene, and phenylacetylene. ... 

EB/SM (ethylbenzene/styrene monomer) process. Styrene can also be made by PO/SM (propylene oxide/styrene monomer) process). This process starts by oxidizing ethylbenzene (C6H5CH2CH2) to its hydroperoxide (C6H5CH(OOH)CH3), which is then used to oxidize propylene (CH3CH = CH2) to produce propylene oxide (CH3CH2CHO) and phenylethanol (C6H5CH(OH)CH3). The phenylethanol is then dehydrated to give... 

Monsanto disclosed the manufacture of ethylbenzene through a different approach by the methylation of toluene in the side chain.318 A cesium-exchanged faujasite promoted by boron or phosphorus is used as the catalyst. Toluene and methanol (5 1) reacting at 400-475°C produce an ethylbenzene-styrene mixture at very high toluene conversion. About 50% of the methanol is converted to carbon monoxide and hydrogen, which is a disadvantage since such a plant should operate in conjunction with a methanol synthesis plant. 

Figure 13.45. Number of stages per meter (reciprocal of HETP), pressure loss per meter and pressure loss per theoretical stage in a 500 mm dia column filled with metal pall rings. Other charts in the original show the effects of packing height and column diameter, as well as similar data for Raschig rings (Billet, 1979). (a) Methanol/ethanol at 760Torr and total reflux in a column 500 mm dia. (b) Ethylbenzene/styrene at 100 Torr and total reflux in a column 500 mm dia.

Epoxy ethylbenzene, Styrene oxide, see Phenyloxirane, 2949b... 

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