Phthalic anhydride from naphthalene

Fumaric acid may be prepared by heating maleic acid, with or without catalysts. It is also obtained as by-product in the manufacture of phthalic anhydride from naphthalene. The acid is a solid melting at 284°C. Fumaric acid is sometimes preferred to maleic anhydride as it is less corrosive, it tends to give lighter coloured products and the resins have slightly greater heat resistance. 

An alternative route to phthalic anhydride is the partial oxidation of naphthalene. The heat of reaction is — 430 kcal/mol. This reaction can be performed using a promoted V2O5 catalyst on silica, much like that considered in Example 9.1. Suppose In(fik) = 31.6800—19,100/T for the naphthalene oxidation reaction and that the subsequent, complete oxidation of phthalic anhydride follows the kinetics of Problem 9.3. Suppose it is desired to use the same reactor as in Example 9.1 but with a,>, = 53g/ m. Determine values for and T aii that maximize the output of phthalic anhydride from naphthalene. 

Extension of the Kunii-Levenspiel bubbling-bed model for first-order reactions to complex systems is of practical significance, since most of the processes conducted in fluidized-bed reactors involve such systems. Thus, the yield or selectivity to a desired product is a primary design issue which should be considered. As described in Chapter 5, reactions may occur in series or parallel, or a combination of both. Specific examples include the production of acrylonitrile from propylene, in which other nitriles may be formed, oxidation of butadiene and butene to produce maleic anhydride and other oxidation products, and the production of phthalic anhydride from naphthalene, in which phthalic anhydride may undergo further oxidation. 

Phthalic Anhydride from Naphthalene. The accepted mechanism for the highly exothermic solid catalyzed oxidation of naphthalene to produce phthalic anhydride is... 

Air, often in the presence of a catalyst. Examples of this method are the preparation of phthalic anhydride from naphthalene by air and vanadium oxide (Wohl s method, page 171), and the analogous oxidation of anthracene to anthraquinone. In the latter case, anthracene which is not entirely pure can be used. 

Phthalic Anhydride from Naphthalene hy Catalytic Oxidation ... 

Phthalic Anhydride. The preparation of phthalic anhydride from xylene is described by Parks and Allard (85) and Levine (65). Phthalic anhydride from naphthalene is discussed by Downs (24), Shreve and Wilborn (106), Ellis (28), Hunter (50), Young (127), and Nash (79). 

Polycarboxylic acid anhydrides by oxidation of aromatic compounds, e.g.—phthalic anhydride from naphthalene or o-xylene and also maleic anhydride from benzene... 

Determine values for Tjn and r aii that maximize the output of phthalic anhydride from naphthalene. 

The manufacture of phthalic anhydride from naphthalene by the fluidized-bed process is outlined in Chapter 9.3.1. 

Theoretical approaches to catalysis in the 1920s drew some criticism from those working at the laboratory bench. One such critic was Charles R. Downs, who had developed vapor-phase oxidation processes for making maleic acid from benzene and phthalic anhydride from naphthalene for Barrett Chemical Co. (20) ... 

During the manufacture of phthalic anhydride from naphthalene and 6>-xylene, small amounts of MA, citraconic anhydrides, and benzoic acid are coproduced.MA comprises 6% of the product.In some cases, after removal of phthalic anhydride by condensation, the exhaust gases are scrubbed with water. In many cases, the aqueous solution of maleic acid is recovered in the form of fumaric acid. Koppers in the United States recovers 10 MM lb of MA from the phthalic plant. ... 

You have recendy joined the TBWS Chemical Corporatiom One of TBWS s major businesses has always been production of phthalic anhydride from naphthalene. Phthalic anhydride production is integrated as part of a large chemical plant, in which naphthalene is produced and in which phthalic anhydride is immediately used to make polyester resins. In recent years, there have been some problems. Some end users have complained about the quality of the resins produced and have taken their business to other companies that produce phthalic anhydride from o-xylene. Therefore, our plant, which had been designed to produce 100,000 metric tons/year of phthalic anhydride from naphthalene, was scaled back to about 80,000 metric tons/year several years ago. We are now forced to scale down production once again due to the loss of another large customer. Marketing informs us that we may lose additional customers. 

Figure C.5 Process Flow Diagram for the Production of Phthalic Anhydride from Naphthalene (Unit 700)...

Although BASF are said to have produced phthalic anhydride by oxidizing naphthalene as early as 1916, the first serious investigations were described by H. D. Gibbs and his associates at the US Bureau of Chemistry. Gibbs and Condover were granted a large number of patents from 1917 for the production of phthalic anhydride from naphthalene. ... 

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