DE1618689B - Process for the preparation of diethylbenzene by disproportionation of ethylbenzene - Google Patents

Claims (1)

1 2 2,528,893 and 2,683,759 are admittedly Claim: formation of other catalysts (HF + BF ₃ , or HF + TiF ₁ ) higher yields of diethylbenzene achieved, Process for the production of diethylbenzene, however, the working conditions are less favorable in several respects due to the disproportionation of ethylbenzene. The used fluorine water increased temperature and in the presence of AlCl ₃ substance is very poisonous, highly aggressive and conditional as a catalyst, thereby gekennzeich- special protective measures in operation, furthermore are net that one from the catalytic ethylbenzene the suggested amounts of catalyst are relatively high. Reforming petroleum in the presence of 3 to 10, as is the case with the United States patent process preferably of 5 percent by weight AlCl ₃ , based on 2 683 759 200 percent by volume HF and 1 mol of TiF ₄ for the amount of ethylbenzene, consumed at a temperature of 1 mol of ethylbenzene.
80 to 100 ° C for about 5 minutes dispro- The process of the invention eliminates all of these portioned. Disadvantage. It's in a very short working time with relative low and non-toxic amounts of catalyst without 15 special protective measures can be implemented in the company. The device required is much simpler than with the known methods. It enables the production of diethylbenzene in The present invention relates to a process for a final yield of 70% with a conversion of the production of diethylbenzene by disproportionate 20 33 ° / ₀ ethylbenzene to diethylbenzene, which is the main production of ethylbenzene at elevated temperature and mainly from a mixture of m- and p- Isomeric presence of AlCl ₃ as a catalyst. with only small proportions of o-isomers. in the There are several methods of making comparisons to U.S. Patents 2,582,893 and Known diethylbenzene. Of these processes, if the 2,683,759 is the capacity of the reactor is much higher. Alkylation of benzene with ethylene in the presence of 25 at the same time are the facilities for its manufacture Aluminum chloride or the alkylation of ethyl from diethylbenzene easier. benzene mentioned with ethylene. The first-mentioned process of the invention for the preparation of driving has the disadvantage that low yields of diethylbenzene are obtained by disproportionation of ethyl-diithylbenzene, since the latter is characterized as a secondary benzene at elevated temperature and in the presence of product in the process for the preparation of ethyl-30 AlCl ₃ as a catalyst that benzene is obtained in addition to other polyethylbenzenes. one ethylbenzene from catalytic reforming The second process mentioned overcomes that of petroleum in the presence of 3 to 10, preferably of the disadvantages of the first-mentioned process, 5 percent by weight of AlCl ₃ , based on the ethylbene, as the main product of the reaction is diethyl zene, at a temperature of 80 to 100 `` C while receiving benzene in an increased yield. This procedure is disproportionate for about 5 minutes,
drive have the disadvantage that a considerable tech- The following example explains the invention, Nical effort is required to produce ethylene on the one hand. . by dehydration of ethyl alcohol or by example To produce pyrolysis of refinery gas and other - in a with a plastic made of phenol-formaldehyde- on the other hand, carry out the alkylation in the presence of aluminum-40 hyd-condensation products lined vessel made of chloride; In addition, plants are required- 100 g of ethylbenzene are produced with a purity of about 98% for diethylbenzene, as is produced in the catalytic reforming of ethylene sources. Petroleum accrues, and 5 g of AICI ₃ introduced. Then it will be It is also known that diethylbenzene can be heated to 100 "C by dis-, with the intimate contact between proportioning of ethylbenzene. After 45 the ethylbenzene and the catalyst by vigorous Liebigs "Annalen der Chemie", Vol. 270, 1892, p. 155 stirring is guaranteed. _{to 159, AlCl 3 is} used as a catalyst for this purpose. After about 5 minutes, an optimal di- There are no further details about the suitable catalyst ethylbenzene concentration in the reaction mass. It is sufficient at temperatures of 100 "C;. This is composed of 22 weight percent benzene, and worked 136 ⁰ C. At 100 C for 10 hours was 50 41 weight percent ethylbenzene, 33 ° / ₀ m- and worked plang, ^r at 136 C of The experiment was interrupted after 2 hours of diethylbenzene, 1.5% o-diethylbenzene and 2.5%. In US Pat. No. 2,528,893, weight percent polyethylbenzenes together. Drying and Fractional use of AlCl ₃ as a catalyst for the disproportionation of the reaction product is obtained m- and p-Di portioning of ethylbenzene to diethylbenzene then 55 ethylbenzene with a purity of above 99% with indicated that when a mixture is treated one Final yield of 70% at a conversion of from 3 moles of benzene and 1.5 mole of diethylbenzene while 33 weight percent of the ethylbenzene employed. for 3 times with AlCl _3, the diethylbenzene to about 50% increase in diethylbenzene yield w earth was converted back to · ethylbenzene. An incentive for finally the polyethylbenzenes together with the expert to use AlCJ ₃ as a catalyst for the dispro · ^6o unreacted ethylbenzene in the disproportionation of ethylbenzene was attributed to the tion stage. As a result of the large difference in boiling point, apart from the long working hours, the benzene formed cannot be given. get pure by a simple rectification and In the US processes, patents can be used for other purposes.