Recent advances in the industrial alkylation of aromatics: new catalysts and new processes

doi:10.1016/S0920-5861(01)00511-9

Catalysis Today

Volume 73, Issues 1–2, 1 April 2002, Pages 3-22

https://doi.org/10.1016/S0920-5861(01)00511-9 Get rights and content

Abstract

Huge improvements towards the development of environmentally friendly processes have been achieved in the alkylations of aromatics with olefins, since the last four or five decades. Particularly, much efforts have been devoted to the research of solid catalysts adequate to substitute mineral or Lewis acids and free bases traditionally employed as catalysts in the acid or base catalyzed alkylations. Here we review the options industrially worthy of note in the alkylations of benzene and toluene for the production of ethylbenzene (EB), cumene, linear alkyl benzene and cymene. We also discuss features of different zeolites as a function of their activity and selectivity in the reactions considered.

Introduction

The alkylation of aromatic hydrocarbons with olefins is applied on a large scale in the chemical industry [1]. Consider that about 70% of the 29.3 million tonnes accounting the world benzene demand in 1999, were expected to be consumed by acid catalyzed alkylation with ethylene and propylene, 53 and 17%, respectively for the production of ethylbenzene (EB) and cumene. Analogously, p-diisopropylbenzene, C10–C14 linear alkylbenzenes (LABs), cymene, p-ethyltoluene and 4-t-butyltoluene are also important chemical intermediates obtained by acid alkylation of benzene or toluene aromatic ring. Finally, other chemical intermediates, such as 5-(o-tolyl)-pentene-2, isobutylbenzene and t-amylbenzene, are produced by side-chain alkylation of aromatics, catalyzed by base [2].

In many industrial processes these alkylations are still performed with catalysts showing drawbacks. Often such catalysts are strong mineral acids or Lewis acids (e.g. HF, H₂SO₄, and AlCl₃), which are highly toxic and corrosive. They are dangerous to handle and to transport as they corrode storage and disposal containers. Often, the products need to be separated from the acid with a difficult and energy consuming process. Finally, it occurs frequently that these acids are neutralized at the end of the reaction and, therefore, the correspondent salts have to be disposed. Similar problems arise when free bases are used as catalysts.

In order to avoid these problems many efforts have been devoted to the search of solid acid and base catalysts more selective, safe, environmentally friendly, regenerable, reusable and which have not to be destroyed after reaction. The aim of this contribution is to summarize some examples of new industrial processes based on the aforementioned solid catalysts. Only the alkylations accounting for the largest capacity will be discussed.

Section snippets

Ethylbenzene

EB is the key intermediate in the manufacture of styrene, which is one of the most important industrial monomer. Almost all EB is synthesized from benzene and ethylene, the worldwide capacity amounting to around 20 million tonnes per year.

Introduction and traditional process

Cymene (methylisopropylbenzene) production is commercially carried out by alkylation of toluene with propylene (Scheme 3).

m-Cymene and p-cymene are intermediates for the production of m- and p-cresol, by oxidation and acid cleavage. Although the demand for cymene is much lower than for cumene, some commercial units are operating with an installed capacity of around 40 kilo tonnes per year. The alkylation produces a mixture of cymene isomers (i.e. o-, m- and p-). The most preferred isomer

Introduction and traditional processes

Linear alkylbenzene (LAB) is the primary raw material used to produce LAB sulfonate (LAS), a surfactant detergent intermediate. LAB global demand is about 2.7 million metric tonnes per year, its growth being mainly expected in the less developed areas of the world [42].

Traditional processes [43] for LAB production all include an alkylation unit with liquid catalysts, which depending on the process, may implies the following.

1.
Alkylation of benzene with olefins C10–C14 in the presence of HF.
2.

Conclusions

For the aromatic alkylations accounting the largest productions, new solid catalysts and new processes conforming the environmental and safety concerns are currently available. Various solid catalysts based on different zeolites have been developed for the production of EB and cumene up to the industrial scale. The data available do not allow to easily ascertaining which the best catalyst is. However, to our knowledge and according to molecular mechanics calculations, it seems that the

References (57)

Calculations computed by means of Outkumpu HSC Chemistry® for Windows, Chemical Reactions and Equilibrium Software with...
S.-H. Wang, Styrene, PEP Report 33C, Supplement C, Process Economics Program, SRI International, March 1993, p. 4-2 and...
L. Forni et al.
Appl. Catal. A
(1995)
J.C. Cheng, T.F. Degnan, J.S. Beck, Y.Y. Huang, M. Kalyanaraman, J.A. Kowalasky, C.A. Loehr, D.N. Mazzone, Science and...
J.C. Cheng, A.S. Fung, D.J. Klocke, S.L. Lawton, D.L. Lissy, W.J. Roth, C.M. Smith, D.E. Walsh, US Patent 5,453,554 to...
C. Perego, S. Amarilli, R. Millini, G. Bellussi, G. Girotti, G. Terzoni, Microporous Mater. 6 (1996) 395;...
G. Girotti, O. Cappellazzo, E. Bencini, G. Pazzuconi, C. Perego, European Patent 847,802A1 to EniChem...
C. Perego et al.
Microporous Mesoporous Mater.
(1999)
H. Fiege, Ulmann’s Encyclopedia of Industrial Chemistry, Vol. A8, 1987, p....
B. Wichterlova et al.
J. Catal.
(1994)

K.S.N. Reddy et al.

Appl. Catal. A

(1995)

A.B. Halgeri et al.

Appl. Catal. A: Gen.

(1999)

M.J. Schlatter et al.

J. Am. Chem. Soc.

(1953)

D.M. Roberge et al.

Appl. Catal. A: Gen.

(2001)

D. Buhl et al.

Appl. Catal. A: Gen.

(1999)

Chem System, Process Evaluation Research Planning (93S10), Tarrytown, New York,...

J.L. Berna Tejero, A.M. Danvila, US Patent 5,146,026 to Petroquimica Espanola, S.A. Petresa...

C. de Castro et al.

J. Catal.

(2000)

S. Amarilli, C. Perego, unpublished...

H.G. Franck, J.W. Stadelhofer, Industrial Aromatic Chemistry, Springer, Berlin,...

J.S. Beck, W.O. Haag, in: G. Ertl, H. Knoezinger, J. Weitkamp (Eds.), Handbook of Heterogeneous Catalysis, VCH,...K. Tanabe et al.

Appl. Catal. A: Gen.

(1999)

A.A. O’Kelly et al.

Ind. Eng. Chem.

(1947)

P.B. Venuto et al.

J. Catal.

(1966)

N.Y. Chen et al.

Catal. Rev. Sci. Eng.

(1986)

C.G. Wight, US Patent 4,169,111 to Union Oil Company of California...

R.A. Innes, S.I. Zones, G.J. Nacamuli, US Patent 4,891,458 to Chevron USA Inc....

F. Cavani, V. Arrigoni, G. Bellussi, European Patent 0432814 A1 to Eniricerche, EniChem, Snamprogetti...

G. Bellussi et al.

J. Catal.

(1995)

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Recent advances in the industrial alkylation of aromatics: new catalysts and new processes

Abstract

Introduction

Section snippets

Ethylbenzene

Introduction and traditional process

Introduction and traditional processes

Conclusions

Appl. Catal. A

Microporous Mesoporous Mater.

J. Catal.

Appl. Catal. A

Appl. Catal. A: Gen.

J. Am. Chem. Soc.

Appl. Catal. A: Gen.

Appl. Catal. A: Gen.

J. Catal.

Appl. Catal. A: Gen.

Ind. Eng. Chem.

J. Catal.

Catal. Rev. Sci. Eng.

J. Catal.