US1285117A - Process for the manufacture of phthalic anhydrid, phthalic acid, benzoic acid, and naphthaquinones. - Google Patents

Description

San Francisco,

* invented a new and useful Process 30 sulfate and that naphtha 40 frequentl I mixture, forcing the HARRY D. GIBBS, OF SAN FRANCISCO, CALIFORNIA,

AND COURTNEY CONOVER. or

PHILADELPHIA, PENNSYLVANIA.

PROCESS FOR THE MANUFACTURE OF P HTHALIC AN HYBRID,

PHTHALIC ACID, BEN ZOIC ACID, AND N APHTHAQUINON ES.

N 0 Drawing.

Specification of 146MB Patent. Patented Nov. 19, 1918. Application filed February 17, 1917. Serial No. 149,361.

(DEDICATED TO THE PUBLIC.)

To all whom it may concern:

Be it known that we, HARRY D. GIBBS and COURTNEY CoNovEn, citizens of the United States of America, residing in the city of county of San Francisco, State of California, and in the city of Philadelphia, county of Philadelphia, State of Pennsylvania, respectively, (whose ostoflice address is Washington, D. (1,2 ave 'or the Manufacture of Phthalic Anhydrid, Phthalic Acid, Benzoic Acid, and N aphthaquinones. This application is made under the act of March 3, 1883, chapter 143 (22 Stat, 625), la and the invention herein described and claimed may be used by the Government of the United States or any of its ofiicers or employees in prosecution of work for the Government, or any person in the United States, without payment to us or any royalt ' gur invention relates to a process for the manufacture of phthalic anhydrid, phthalic acid, benzoic acid and naphthaquinones from 25 naphthalen It is well known that phthalic anhydrid and phthalic acid are commonly produced by the oxidation of naphthalene by means of sulfuric acid in the presence of mercury uinones are produced by the oxidation 0 naphthalene by various oxidizing agents in liquid form and that benzoic acid is commonly produced from toluene. To manufacture phthalic anhydrid, phthalic acid, benzoic acid, and the methods commonly naphthaquinones by employed in general requires the employment of costly oxidizing reagents. In addition products obtained by these methods are produced in forms which make them di cult to separate and purify. The object of our invention is to provide a process for the manufacture of the materials named which will be free from the objec- 46; tionable features of the processes employed at resent. V

ur invention consists in the production of phthalic anhydrid, phthalic acid, benzoic acid and napthaquinones from naphthalene 50 by heating the naphthalene until it passes into the vapor phase, mixing this naphthalene vapor with anoxygen-containinggas mixture of gases into close contact with finely divided oxids of from 250 C. to 650 C., under which treat ment the naphthalene is oxidized to form the valuable products named, together with carbon dioxid and water.

The temperature and range of 250 to 650 C. is that range in which the reaction producing phthalic anhydrid progresses to a practical degree. The preferred temperature is between 350 and 550 (3., for the reason that the yield of phthalic anhydrid is greater at this range.

To illustrate the practical operation of our process we shall describe in detail the preferred procedure. Naphthalene is melted and is caused to flow continuously at a measured rate into a heated chamber where it is volatilized. This vapor of na hthalene is then mixed with air in excess 0 the proportion theoretically required to oxidize naphthalene to phthalic anhydrid, the mixture containing preferably at least four times the amount of air theoretically required. The mixture of air and naphthalene vapor is passed into a reaction chamber maintained at a temperature ranging from 350 to 550 C., the preferred temperature being 500 C. In this chamber the gas mixture is forced into. close contact with oxids of vanadium in the form of a fine powder. This powder is supported on trays where by means of baflie plates, the current of mixed gases is forced through it. The gases are kept under pressure onlysuflicient to cause them to flow continuously throu h the reaction chamber. The roduets of t e reaction, consisting of pht alic anhydrid and other oxidation products of na hthalene, are condensed, together with unchanged naphthalene, by well-known processes. Phthalic anhydrid, together with small portions of other oxidation products, is separated from the unchanged naphthalene by fractional sublimation.

We have discovered that the process as above described may be varied in many ways and yet will produce one or all of the oxidation products named. Thus, oxy en may be substituted wholly or in part or air, or air may be mixed with .a gas which is relatively inert under the conditions obtaining in the process. The oxids of vanadium may be mixed wiiii oii cr SHiDSiIIUQQES, sucis. as magnesium ouid, oikoiinc corih uuids other mciaiiic ouids osil-csios, OI iuci'i uiuccriois. The gas miuiuic may be iorougiii in couioci; with or forced through the coiuiysi iu mung difici'eut ways. Tho proportioned uu giiiiiuions vapor to tho oxygcu-couisiuiug gas mixtuic may be varied Within wide iimiis And tile reaction products may inc scpui'oicd by voi'ious-wcii-knowu moons Thus thc acid constituents may be dissolved in oikuiinc soiuiious and subsequently freed from their suits icy the addition of suiiuiic or phosphoric acid and thou suioiiiucd. @T the reaction products may Too ii coicd "with ammonia gas or aqueous soiuiions 'oi ommouiu or i'uiious mnii is *zo produce other uscfui mud vaiuubic compounds;

Having thus dcsciibsd our invention We ciuim- Ii. A process for the manufacture of phiiioiic auiiydrid, phtiiuiic acid, iosuzoic ucid and uopiiiiuiquiuoucs, which process cousisis iu suoicciiug uu oiiiiiuicuc gusoous siccs u d iuixcd cuygoucontaining uiixouir "1c iiis u-c'iiou diiifczrmg iioui ills fractional su imiutiou mentioned ubovo.

i'uuudium oxids hsaicd to tciupcruiurss rungiugiii-om 350 io 55%? csniiguudc.

25.. A process fox the manufacture of 'piusimiic ouiuyduid, piotixsiic acid, ioenzoic acid and uupiiihuquiuouss, which process consists iu subjecting uuphtimicuc iii ti c