Disproportination and Transalkylation of alkyl benzene

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Ayad Idrees SlemanSupervisor by: Dr. Kanaan R .AhmadMAY 2016 2016:AD 2716K 1437HDisproportionation & Transalkylation Of Alkyl benzenes over Zeolite Catalysts

1Disproportionation & Transalkylation Of Alkyl benzenes over Zeolite Catalysts5/12/2016Ayad Idrees

ContentPageThe Aim of Study31.Introduction42.Alkylation53-Disproportionation74-Transalkylation85-Zeolite catalysts 10Reference11

Table Content2Disproportionation & Transalkylation Of Alkyl benzenes over Zeolite Catalysts


Catalytic alkyl-transfer (transalkylation, disproportionation) reactions, reaction conditions, and catalysts of alkylaromatics were studied for the aim of sorting out the principles that governs them.1.The Aim of Study3Disproportionation & Transalkylation Of Alkyl benzenes over Zeolite Catalysts


Transalkylationis a chemical reaction involving the transfer of analkyl groupfrom oneorganic compoundto another. The reaction is most commonly used for the transfer of methyl groups betweenbenzenerings and is widely used in thepetrochemical industryto manufacturep-xylene ,styrene,and otheraromatic compounds. Motivation for using trans alkylation reactions is based on a difference in production and demand for benzene, toluene, and xylenes. During the process of xylene production, a number of reactions such as transalkylation disproportionation, and dealkylation take place. The methyl groups are shifted from one benzene ring to the other via transalkylation and disproportionation to produce mixed xylenes.

1.Introduction:

4Disproportionation & Transalkylation Of Alkyl benzenes over Zeolite Catalysts


2.AlkylationAcid catalysts used for alkylation of aromatic hydrocarbons are Brnsted acids containing acidic protons These include acidic halides such as aluminium chlorides and boron fluoride, acidic oxides and zeolites protonic acids especially sulfuric acid, hydrofluoric acid and phosphoric acid, and organic cation exchange resins. Metal halides usually called Friedel-Crafts catalysts, have been used extensively for aromatic alkylation in the past, they are highly active and allow the reaction to be carried out in liquid phase at low temperatures




Transalyklation as used by the petrochemical industry is often used to convert toluene into benzene and xylenes. This is achieved through a disproportionation reaction of toluene in which one toluene molecule transfers its methyl group to another one. The reaction is not selective, and the xylene produced can be ortho, meta, or para. There is a higher demand for para xylene, so it is often separated out, and the reaction is allowed to produce more para product

3-Disproportionation


Disproportionation & Transalkylation Of Alkyl benzenes over Zeolite Catalysts5/12/2016Ayad Idrees 7

Unlike disproportionation, in Transalkylation one of the alkyl groups is transferred from one Alkylaromatic molecule to another aromatic molecule of a different kind. Transalkylation Is transfer of alkyl group from 1,2,4-trimethylbenzene to toluene to produce xylene 4-Transalkylation8Disproportionation & Transalkylation Of Alkyl benzenes over Zeolite Catalysts

Disproportionation & Transalkylation Of Alkyl benzenes over Zeolite Catalysts85/12/2016Ayad Idrees


Disproportionation & Transalkylation Of Alkyl benzenes over Zeolite Catalysts95/12/2016Ayad Idrees

Zeolites are crystalline and porous materials with an open structure that consist of AlO4 and SiO4 tetrahedral units linked through oxygen atoms. Owing to their unique properties in ion exchange and adsorption capacity and catalytic activity, zeolites have been widely used as adsorbents, molecular sieving agents and catalysts for a variety of different chemical reactions.

5-Zeolite catalysts 10Disproportionation & Transalkylation Of Alkyl benzenes over Zeolite Catalysts


1. Tsai, Tseng-Chang "Disproportionation and transalkylation of alkylbenzenes over zeolite catalysts". Elsevier Science, 1999 https://en.wikipedia.org/wiki/Transalkylation 3. A L K Y L T R A N S F E R ( T R A N S A L K Y L A T I O N ) R E A C T I O N S O F A L K Y L A R O M A T I C S O N S O L I D A C I D C A T A L Y S T S4. Stefanidakis, G.; Gwyn, J.E. (1993). "Alkylation". In John J. McKetta. Chemical Processing Handbook. CRC Press. pp. 80138. ISBN 0-8247-8701-3

Reference 11Disproportionation & Transalkylation Of Alkyl benzenes over Zeolite Catalysts

Disproportionation & Transalkylation Of Alkyl benzenes over Zeolite Catalysts12

Disproportination and Transalkylation of alkyl benzene

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