Mar 12, 2012 - FOREIGN PATENT DOCUMENTS ... patent is extended or adjusted under 35. _. _. _ ... The zeolite catalyst is an X-type zeolite modi?ed.
USOO8697593B2
(12) United States Patent
(10) Patent N0.:
Al-Khattaf et al. (54)
(45) Date of Patent:
ZEOLITE CATALYST FOR THE
4,463,204 A *
ALKYLATION OF TOLUENE WITH ,
_
(73)
£91 at al~
,
1u
4,613,720 A
502m
............................... ..
9/1986 BonifaZ et al.
4,752,596 A *
Inventors: Sulalman S. Al-Khattaf, Dhahran (SA);
Apr. 15, 2014
7/1984 Liu ............................. .. 585/437
2 *
METHANOL
(75)
US 8,697,593 B2
5,063,433 A
6/1988
Bergna et a1. ................. .. 502/64
11/1991 Barthomeuf et a1,
Hideshi Hattori, Sapporo (JP);
6,114,268 A *
9/2000 Wu et a_l. ....................... .. 502/74
Balkrishna B. Tope, Dhahran (SA);
7,011,811 B2
3/2006 Eloman
Assignees: King FahdMI University of Petroleum
FOREIGN PATENT Pelati DOCUMENTS et
and Minerals, Dhahran (SA); King
DE
33 30 790 A1
3/1985
AbdulaZIZ City for Science and
JP
57_68144
4/1982
Technology, Riyadh (SA)
_
_
* Cited by examiner
(*)
Notice:
Subject to any disclaimer, the term of this patent is extended or adjusted under 35
U_S_C_ 154(b) by 107 days_
_
_
_
Primary Exammer * Elizabeth Wood (74) Attorney, Agent, or Firm * Richard C Litman
(21) App1.No.: 13/418,202 (22) Filed: (65)
Mar. 12, 2012
(57)
Prior Publication Data Us 2013 /023773 5 A1 Sep 12 2013 '
(51) Int_ CL BO1] 29/06 (52) us CL
(58)
’
(200601)
ABSTRACT
The zeolite catalyst is provided for the alkylation of toluene With methanol to selectively produce styrene and ethylben zene. The zeolite catalyst is an X-type zeolite modi?ed
sequentially, ?rst by ion-exchange With alkali metals, such as cesium, to replace all exchangeable sodium from the zeolite, and then by mixing the modi?ed zeolite With borate salts of a
USPC ................. .. 502/73; 502/60; 502/65; 502/66;
metal such as lanthanum, zirconium, copper, zinc orthe like
502/74; 502/75; 502/79 Field of Classi?cation Search USPC ______________________ __ 502/60, 65, 66, 73, 74, 75s 79 See application ?le for complete search history,
The initial zeolite composition has a Si to Al molar ratio of approximately 1 to 10, and is preferably either zeolite X or zeolite 13X. The zeolite composition is ion-exchanged With cesium to replace at least 50% of the exchangeable sodium in
the zeolite composition. The ion-exchanged zeolite compo (56)
References Cited U.S. PATENT DOCUMENTS 4,115,424 A 4,140,726 A 4,429,174 A
9/1978 Unland et al. 2/1979 Unland et al. 1/1984 Teng et a1.
sition is then mixed With a borate salt to form the zeolite
catalyst for the alkylation of toluene With methanol for the
selective production of styrene and ethylbenzene. 2 Claims, No Drawings
US 8,697,593 B2 1
2
ZEOLITE CATALYST FOR THE ALKYLATION OF TOLUENE WITH METHANOL
styrene and ethylbenzene. The zeolite catalyst is an X-type zeolite that is modi?ed sequentially, ?rst by ion-exchange with alkali metals, such as cesium, to replace all exchange able sodium from the zeolite, and then by mixing with borate
BACKGROUND OF THE INVENTION
salts of metals, such as lanthanum, zirconium, copper, zinc or the like. As used herein, an X-type zeolite (or zeolite X) is a synthetic faujasite zeolite having a silica to alumina molar ratio of about 2 to 3 (a silicon to aluminum molar ratio of about 1 to 1.5). In general, the zeolite catalyst acts as an alkylating agent that alkylates an aromatic compound to pro duce a C8 aromatic product, particularly styrene and ethyl
1. Field of the Invention
The present invention relates the production of styrene, and particularly to a zeolite catalyst for the alkylation of toluene
with methanol to selectively produce styrene and ethylben zene.
2. Description of the Related Art
benzene, with styrene being prominently and selectively
Styrene is a commercially valuable commodity typically produced using benzene and ethylene feeds in a two-step process. The ?rst step is the alkylation of the benzene with ethylene to produce ethylbenzene. In the second step, ethyl benzene is dehydrogenated to form styrene. This reaction occurs at high temperatures (greater than 600° C.) using an iron oxide catalyst. The reaction is highly endothermic and
formed. The initial zeolite composition has a Si to Al molar ratio of approximately 1 to 10, and is preferably either zeolite X or zeolite 13X having a surface area density of between approxi
thermodynamically limited. The production of styrene from ethylbenzene consumes
20
mately 400 m2/g and approximately 600 m2/g. In the zeolite X or zeolite 13X, the charge of the acidic zeolite (containing aluminum) is balanced by the sodium cations, which are typically present in amounts suf?cient to neutralize the nega
ten times more energy than the production of most other
tive charge.
chemicals, and is also a major contributor to the production of harmful greenhouse gases, such as methane gas emissions. The current global production capacity of styrene is near 26 million tons per year and is increasing at a steady rate (~3 .7% per year). Styrene is used as an intermediate chemical in the
The zeolite composition is ion-exchanged with cesium to replace at least 50% of the exchangeable sodium in the zeolite
composition. The ion-exchanged zeolite composition is then 25
lent and trivalent cations of Mg, Cr, Fe, Zn, Mn, Co, Ni, Cu, Cd, Sn, Al, Ga, In, Fe, V, Cr, Ti, Pb, Mn, Co, Rh, Ni, Si or
production of various polymers, mainly polystyrene.
mixtures thereof. The mixture forms the zeolite catalyst for the alkylation of toluene with methanol for the selective pro
There is a need for an alternative technique for the produc
ing styrene that is relatively energy ef?cient and that reduces greenhouse gas emissions. Thus, a zeolite catalyst for the alkylation of toluene with methanol solving the aforemen tioned problems is desired.
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35
The zeolite catalyst for the alkylation of toluene with methanol provides a catalyst and a process for producing styrene that is energy ef?cient and reduces greenhouse gas emissions compared to conventional methods. The zeolite
inert diluent gas may be added to the feed gas mixture. The that the feed gas mixture has a molar ratio of the toluene and methanol mixture to the nitrogen gas of between about 1 to l 40
and about 6 to l . Alternatively, the feed gas mixture may have a molar ratio of the toluene to the nitrogen gas of between about 0.5 to l and about 6 to 1. As a further alternative, the feed gas mixture may have a molar ratio of the methanol to the nitrogen gas of between about 0.2 to l and about 6 to 1.
45
In the following, the percentage of methanol conversion is calculated as [(methanol wt % in the feed gas)—(methanol wt % in the product)>
