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Maleic from benzene

Process Technology Evolution. Maleic anhydride was first commercially produced in the early 1930s by the vapor-phase oxidation of benzene [71-43-2]. The use of benzene as a feedstock for the production of maleic anhydride was dominant in the world market well into the 1980s. Several processes have been used for the production of maleic anhydride from benzene with the most common one from Scientific Design. Small amounts of maleic acid are produced as a by-product in production of phthaHc anhydride [85-44-9]. This can be converted to either maleic anhydride or fumaric acid. Benzene, although easily oxidized to maleic anhydride with high selectivity, is an inherently inefficient feedstock since two excess carbon atoms are present in the raw material. Various compounds have been evaluated as raw material substitutes for benzene in production of maleic anhydride. Fixed- and fluid-bed processes for production of maleic anhydride from the butenes present in mixed streams have been practiced commercially. None of these... [Pg.453]

Capacities of maleic anhydride faciUties worldwide are presented in Table 7. The switch of feedstock from benzene to butane was completed in the United States in 1985, being driven by the lower unit cost and lower usage of butane in addition to the environmental pressures on the use of benzene. Worldwide, the switch to butane is continuing with 58% of the total world maleic anhydride capacity based on butane feedstock in 1992. This capacity percentage for butane has increased from only 6% in 1978. In 1992, 38% of the total world maleic anhydride capacity was based on benzene feedstock and 4% was derived from other sources, primarily phthaUc anhydride by-product streams. [Pg.458]

Maleic anhydride [108-31-6] M 98.1, m 54 , b 94-96 /20mm, 199 /760mm. Crystd from benzene, CHCI3, CH2Cl2or CCI4. Sublimed under reduced pressure. [Skell et al. J Am Chem Soc 108 6300 7956.]... [Pg.280]

For many years maleic anhydride (MA) was made from benzene by oxidation and loss of two moles of CO2. Even as late as 1978 83% of maleic... [Pg.182]

The oxidation of benzene to maleic anhydride is generally described by the simplified reaction scheme (Scheme 1, p. 198). Complete oxidation products (CO, C02) are mainly formed from benzene and not by combustion of maleic anhydride itself. Therefore, the parallel character of the reaction scheme predominates, which implies that a high initial selectivity enables high yields to be obtained. [Pg.197]

The activity and selectivity of 19 oxides at 400—450°C were investigated by Germain and Laugier [133], The activities are compared with those for the oxidation of toluene in Fig. 8, and show a linear relationship for the major part of the oxides, the toluene oxidation being approximately twice as fast as the benzene oxidation. The only selective catalysts, i.e. those that produce substantial amounts of benzoquinone and maleic anhydride from benzene, and benzaldehyde and benzoic acid from toluene are the oxides of V, Mo and W. Remarkably, these oxides clearly deviate from the average correlation in Fig. 8 and show a much higher tol-uene/benzene activity ratio (about 10/1). The order of activity, maximum yield of maleic aldehyde and initial selectivity with respect to benzoquinone is the same for these oxides V > Mo > W. [Pg.201]

MALEIC ANHYDRIDE, MALEIC ACID AND FUMARIC ACID] (Vol 15) -from benzene [BENZENE] (Vol 4)... [Pg.519]

Unsaturated 1,4-Dicarbonyl Reaction. Bandow et al. [144,145] observed the formation of maleic anhydride from benzene, toluene, and o-xylene possibly arising from the HO-initiated oxidation of the expected 1,4-dicarbonyl (CHO)CH=CH(CHO), i.e ... [Pg.128]

The manufacture of phthalic anhydride (E.P., 249,973) from naphthalene, and maleic anhydride (U.S.P., 1,515,299) from benzene, is carried out by oxidation with air or oxygen in presence of V205 as catalyst. [Pg.247]

Scheme 4 Photochemical formation of a 1 2 adduct from benzene and maleic anhydride. Scheme 4 Photochemical formation of a 1 2 adduct from benzene and maleic anhydride.
In the presence of a second dienophile, the ortho adduct can be trapped. Koltzenburg et al. [43] have added duroquinone to a benzene solution of maleic anhydride and obtained a 1 1 1 adduct formed from benzene, maleic anhydride, and duroquinone. [Pg.8]

Maleic anhydride (melting point 52.8°C, boiling point 202°C, flash point 110°C), formerly made from benzene, is now made from butane (Figs. 1 and 2) a switch in manufacturing method that was very rapid and complete. [Pg.314]

Maleic Anhydride. Prior to 1975, benzene was the feedstock of choice for maleic anhydride manufacture. By the early 1980s, for economic reasons, many producers had switched to the n-butane process described in the section n-Butane Derivatives . By 1988, all of the maleic anhydride produced in the United States came from that process. However, about half of the maleic anhydride produced abroad still comes from benzene oxidation, with a small amount being recovered as a coproduct in phthalic anhydride manufacture. [Pg.395]

Phthallc anhydride from naphthalene or o-xylene 1D Maleic 4cld anhydride from benzene... [Pg.577]

A mixture of 34 g. (0.14 mole) of the ketone and 10 g. of zinc dust is heated for 3 hours in a metal bath at a bath temperature of 410°. The material is then heated in a distillation system at 0.4 mm. pressure. The hydrocarbon distilled is recrystallized several times from benzene-ethanol mixture to give 17.2 g. (54%) of 1,2-benzanthracene. Product melting at 155.5-157 is obtained by solution of the 17.2 g. and 1 g. of maleic anhydride in 50 ml. of benzene, refluxing for 3 hours, extraction of the hot solution with aqueous sodium hydroxide solution,... [Pg.33]

Supported vanadla used to promote the selective oxidation of hydrocarbons. Is another example. Vanadia with or without promoters, may be supported on silica (naphthalene oxidation [38]), on tltanla o-xylene oxidation [39]) or on a-alumlna (benzene oxidation [ AO]). It was believed that supports should have open porosity (and associated lower surface area) in order to minimise over oxidation to carbon oxides. However, it was shown that reasonably high activities and selectivitles could be obtained over vanadla supported on high surface area material and it was suggested that low selectivity was, in fact, primarily associated with high acidity on the support [AI]. In agreement with this, vanadla supported on 7-alumina shoved zero selectivity for the production of maleic anhydride from benzene If this Is the case, then a high surface area support with minimal acidity would be desired,... [Pg.48]

Figure 1. Infrared spectra (KBr) of (A) polyimide prepared by photolysis of benzene sobitions of ii,N -hexarnethylenebistnaleirnide (B) polyimi prepared from benzene-maleic anhydride photoadauct (2) and 1,6-hexanediamine and (C) the N,N -bis(n-... Figure 1. Infrared spectra (KBr) of (A) polyimide prepared by photolysis of benzene sobitions of ii,N -hexarnethylenebistnaleirnide (B) polyimi prepared from benzene-maleic anhydride photoadauct (2) and 1,6-hexanediamine and (C) the N,N -bis(n-...
As cited in Chapter 1, the first example of commercial process using an alkane as feedstock, in substitution of the older process starting from benzene, was the synthesis of maleic anhydride from n-butane. Figure 2.66 briefly recalls the reaction scheme on the model surface of the catalyst (vanadyl pyrophosphate) to evidence the... [Pg.180]

Maleic Anhydride. The preparation of maleic anhydride from C4 hydrocarbons is given by Bretton (10). The preparation of maleic anhydride from benzene is described in Faith, Keyes, and Clark (31). Maleic anhydride is an important by-product in the phthalic anhydride process. [Pg.374]

There have been notable shifts in raw materials for the manufacture of maleic anhydride and phenol. Made for many years by the oxidation of benzene, maleic anhydride now is made by a catalytic process from butane. The butane process was found to result in lower costs of operation as well as reduced environmental, safety, and health hazards. Another example is the manufacture of phenol, initially made from benzene or chlorobenzene. Subsequently, however, with large supplies of cumene from the catalytic reaction of benzene and propylene, production came to be dominated by cumene-derived phenol, which, requires a lower capital investment and offers reduced operating expenses as well as reduced environmental and safety problems. A novel... [Pg.410]

In going from benzene to pentacene the largest sum of the free valence of a pair of atoms in a para position increases as does the ease of the diene synthesis in this series. It is well known that maleic anhydride hardly reacts with benzene or naphthalene. A reaction takes place with anthracene and even more readily with naphthacene and pentacene.12... [Pg.191]

The first industrial plant using n-butane to manufacture maleic anhydride was started up by Monsanto in 1984. At the time, 20 per cent of the maleic anhydride production capacity of this company switched from benzene to butane. Since then, three other manufacturers in the United States (Amoco, Ashland and Denka Chemical), and two in Western Europe (Bayer and Huh) have followed a similar procedure, so that ail maleic anhydride produced today in the United States is based on butane feedstock and nearly 50 per cent of worldwide installed capacity operates by this method. The n-butane is oxidized in the vapor phase, in a multi-tube reactor, on a fixed bed of catalyst based on phosphorus, vanadium and iron, deposited on a silica/alumina support... [Pg.304]

Economic data concerning the production of maleic anhydride from benzene, n-butane and olefinic C4 cuts are given in Table 13.4. [Pg.310]


See other pages where Maleic from benzene is mentioned: [Pg.453]    [Pg.453]    [Pg.263]    [Pg.183]    [Pg.577]    [Pg.97]    [Pg.49]    [Pg.9]    [Pg.282]    [Pg.610]    [Pg.577]    [Pg.577]    [Pg.504]    [Pg.12]    [Pg.19]    [Pg.309]    [Pg.377]   
See also in sourсe #XX -- [ Pg.214 ]




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