CA1081714A - Process for the manufacture of styrene - Google Patents
Process for the manufacture of styreneInfo
- Publication number
- CA1081714A CA1081714A CA276,229A CA276229A CA1081714A CA 1081714 A CA1081714 A CA 1081714A CA 276229 A CA276229 A CA 276229A CA 1081714 A CA1081714 A CA 1081714A
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- Prior art keywords
- catalyst
- group
- acid
- phenylacetic acid
- benzyl
- Prior art date
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/10—Preparation of carboxylic acids or their salts, halides or anhydrides by reaction with carbon monoxide
- C07C51/12—Preparation of carboxylic acids or their salts, halides or anhydrides by reaction with carbon monoxide on an oxygen-containing group in organic compounds, e.g. alcohols
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
- C07C1/20—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon starting from organic compounds containing only oxygen atoms as heteroatoms
- C07C1/24—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon starting from organic compounds containing only oxygen atoms as heteroatoms by elimination of water
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C15/00—Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts
- C07C15/40—Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts substituted by unsaturated carbon radicals
- C07C15/42—Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts substituted by unsaturated carbon radicals monocyclic
- C07C15/44—Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts substituted by unsaturated carbon radicals monocyclic the hydrocarbon substituent containing a carbon-to-carbon double bond
- C07C15/46—Styrene; Ring-alkylated styrenes
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/132—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group
- C07C29/136—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH
- C07C29/147—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH of carboxylic acids or derivatives thereof
- C07C29/149—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH of carboxylic acids or derivatives thereof with hydrogen or hydrogen-containing gases
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/035—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides with saturated hydrocarbons
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2521/00—Catalysts comprising the elements, oxides or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium or hafnium
- C07C2521/02—Boron or aluminium; Oxides or hydroxides thereof
- C07C2521/04—Alumina
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2521/00—Catalysts comprising the elements, oxides or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium or hafnium
- C07C2521/12—Silica and alumina
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2521/00—Catalysts comprising the elements, oxides or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium or hafnium
- C07C2521/18—Carbon
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2529/00—Catalysts comprising molecular sieves
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- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A process for the manufacture of styrene which comprises:
(a) oxidizing toluene in the presence of an oxidation catalyst, and acetic acid or proionic acid to form an oxygenated product containing benzyl acetate or benzyl propionate;
(b) contacting the oxygenated product formed in step (a) with a gaseous mixture containing carbon monoxide in the presence of a carbonylation catalyst to form phenylacetic acid;
(c) hydrogenating the phenylacetic acid formed in step (b) in the presence of a hydrogenation catalyst to form phenylethyl alcohol; and (d) dehydrating the phenylethyl alcohol formed in step (c) to form styrene.
A process for the manufacture of styrene which comprises:
(a) oxidizing toluene in the presence of an oxidation catalyst, and acetic acid or proionic acid to form an oxygenated product containing benzyl acetate or benzyl propionate;
(b) contacting the oxygenated product formed in step (a) with a gaseous mixture containing carbon monoxide in the presence of a carbonylation catalyst to form phenylacetic acid;
(c) hydrogenating the phenylacetic acid formed in step (b) in the presence of a hydrogenation catalyst to form phenylethyl alcohol; and (d) dehydrating the phenylethyl alcohol formed in step (c) to form styrene.
Description
~ '7~ 4 1 The present invention relates to a novel four-step
2 method for synthesizing styrene by employing toluene as the
3 starting material. More particularly, it pertains to a new
4 method of making styrene at a markedly reduced cost by:
(a) oxidizing toluene to obtain predominantly banzyl acetate;
6 (b) carbonylating said benzyl acetate wi~h a gaseous mixture 7 containing carbon monoxide to form phenylace~ic acid;
8 (c) hydrogenating said phenylacetic acid ~o form phenyl 9 ethanol; and (d) dehydrating said phenyl ethanol to produce styrene.
ll The art is replete with various processes for the 12 production of styrene, see, e.g., Y. C. Yew and T. H. Vanden 13 Bosch, STYRENE (Supplement A, 1973). However, these various 14 methods have centered around the bàsic concept of dehydrogen-ating ethyl benzene to form styrene as follows:
16 ~ CH2CH3 ~ -C~-CH2 17 *-H2 18 ethyl benzene Styrene ~Eq-l) 19 A variety of ma~erials has been tried as starting materials in order to ob~ain ethyl benzene at a lower cos~, 21 which is used as the reactant in the conventional process 22 described in Equation 1. Representatives of them include 23 benzene and its alkyl derivatives, toluene, vinylcyclohexene, 24 ethylfoluene and l,l-dimethylcyclohexane. None of the chem- ~ ~
25 icals listed above, except benzene, has prove~ to be commer- ~ -26 cially feasible due to poor conversion rates and low yields.
. .
27 In view of the above, benzene and ethylene have been most 28 commonly used to first prepare ethyl benzene and then manu-29 facture qtyrene as follows: ~
. :' '' '' "' ' 8~
1 C6H6 ~ ~H~ CH2 ~ C6U5CH2CH3 3 C6HsCH-GH2 ~ H2 2 (EqO 2) 3 During the last decade or so, however, benzene 4 and ethylene have experienced dramatic price increase. Ac-cordingly, in view of the above, the need has existed for an 6 effective commercial process for manufacturing ~tyrene, 7 which commends itself to a wide variety of co~mercial uses 8 such as the manufacture of synthe~ic rubbers and various 9 styrene-based plastics9 at a lower manufa~turing co$t than 10 conventional techniques known ~o the art. -~
11 It has now been discovered that, by taking a route 2 entirely different from conventional methods such as the 3 one de~cr~bed l~ Equation l or 2~ styrene can be p~oduced 4 at a far lower cast. I~ accordance with the present inven- -tion~ styrene is synthesized in four ma~or steps as follow~:
6 ' (a) oxidizing toluene in the presence of an oxidation cata-17 lyst to form an oxygenated product containing benzyl ace-18 ~ate; ~b) con~acting the oxygenated product formed in step 1q ~a) with a gaseous mixture containing carbon monoxide in the presence of a carbonylation catalyst and preferably a 21 halogen promoter to orm phenylacetic acid; (ç) hydr~gen- ~
2? ating the phenylacetic acid so produced in step `(b) in th~ -~3 presence of a hydrogenation ca~talyst to orm phenylethyL
24 alcohol, and (d) dehydrating the phenyl ethyl alcohol formed ~ -in s~ep (c) ko produce styrene. This novel reaction scheme . .
26 is further illustrated in the following equ~tion:
' ~-`'' ' , .
- ~ -- , .~ ~. . .
7~
~ CHO
~ .
benzyl aldehyde CO/H
CH3 CO/H2O ~ CH COOH
2 (Air)> ~ CH2-O-c-cH3 ~ > ~ O ~ 2 H~
J (a) oxida- ~ J ben~yl ace-tate (b) car- ~ ~ (c) hydro-",' tion ~ bonylation phenyl- genation toluene hydrolysis acetic ~ CH20H acid benzyl alcohol ~ CH2C~120H ~H=CH2 ~ (d) dahydration ~ :
phenylethyl Styrene (Eq. 3) alcohol As the first major step, toluene is contacted with air, oxygen or other oxygen sources, and acetic or propionic acid, in either the liquid or the vapor phase, in the presence of an oxidation catalyst and preferably a promoter at a temperature ranging from about 50 to about 400C., preferably from about 80 to about 300C., and more preferably from about 100 to about 200C. and at a pressure ranging from about 1 to about 50 atm., preerably from about 1 to about 30 atm., more preferably from about 1 to about 20 atm. to produce an oxygenated product con- -, .
taining about 0 to about 20 mole % benzyl aldehyde and about - 80 to 100 mole ~ benzyl acetate or benzyl propionate with the - overall conversion of about 50-100 mole % of toluene as follows~
~) .
5CE3 +~1~O2 +CH3COOH----~C6H5CH2--0-C-CH3 + C6H5CHO
~ + 2H2O (Eq- 4~
Variable-valent metals or compounds of variable-valent ;
' : ' :
: - 4 -1 ~ 8~
1 metals such as Tl, Te, Ce, Au, Bi, Pd, Sb, Mn, V, Ga, As, 2 Co, Cu, Se, Cr or Ag may be e~loyed either alone or in com-3 bination as the oxidation catalyst. Prefexred ca~alysts are 4 the organic and inorganic derivatives of Au, Bi, Tl, Ce, Sç, s Te and Pd. Specific examples o:E these preferred catalytic 6 compounds are inorganlc salts such as chlorides, bromides, 7 iodides, sulfates and nitrates; and organic salts such as 8 acetates and propionates o Au, Bi, Tl, Ce, Se, Te and Pd.
9 These variable-valent metals or their mixtures may be bene-ficially ~upported, especially in the case of the vapor phase oxidation, on such materials as SiO2, Al203, TiO2, 12 ZrO, MgO, acti~e carbon~ kieselg~hr, charcoal and the like.
13 As described in U~S. Patent 3,399,956 (Hirose et al,; 1968), 14 compounds of redox metals such as copper, mercury, chromium, manganese, iron, cobalt ~nd nickel may be prefersbly em-16 ployed, p~rticularly in the case of ~he liquid phasè oxi-17 dation~ alone or together with a halogen ion such as fluor~
18 ide,iodide, bromide or ch~oride in order to promote ~he cat~, 19 lytic e~fect of the variable-valent metallic salts. Xon-~ limiting representatives of such radox metallic d~rivat~ves 21 include inorganic and organic salts, e.g., iodides, bromide~, 22 chlorides, 02ides, nitrates, carbonates and sulfates, and 23 acetates a~d propionates9 o~ the metals lis~ed above. In ;~
24 addition, halides of Groups IA and IIA metals may aleo be beneficially employed as effective promoters for the oæida 26 tion catalystæ. These alkali metal and alkaline earth metal ~7 halides, e.g., chlorides, bromides, iodides and fluorides o~ -28 Li, N~, K, Be, Mg, Sr, B~ and Ca, are known to incre~se the 29 solubility o the v~riable-valent metallic salts in the ~ reaction medium.
: . '
(a) oxidizing toluene to obtain predominantly banzyl acetate;
6 (b) carbonylating said benzyl acetate wi~h a gaseous mixture 7 containing carbon monoxide to form phenylace~ic acid;
8 (c) hydrogenating said phenylacetic acid ~o form phenyl 9 ethanol; and (d) dehydrating said phenyl ethanol to produce styrene.
ll The art is replete with various processes for the 12 production of styrene, see, e.g., Y. C. Yew and T. H. Vanden 13 Bosch, STYRENE (Supplement A, 1973). However, these various 14 methods have centered around the bàsic concept of dehydrogen-ating ethyl benzene to form styrene as follows:
16 ~ CH2CH3 ~ -C~-CH2 17 *-H2 18 ethyl benzene Styrene ~Eq-l) 19 A variety of ma~erials has been tried as starting materials in order to ob~ain ethyl benzene at a lower cos~, 21 which is used as the reactant in the conventional process 22 described in Equation 1. Representatives of them include 23 benzene and its alkyl derivatives, toluene, vinylcyclohexene, 24 ethylfoluene and l,l-dimethylcyclohexane. None of the chem- ~ ~
25 icals listed above, except benzene, has prove~ to be commer- ~ -26 cially feasible due to poor conversion rates and low yields.
. .
27 In view of the above, benzene and ethylene have been most 28 commonly used to first prepare ethyl benzene and then manu-29 facture qtyrene as follows: ~
. :' '' '' "' ' 8~
1 C6H6 ~ ~H~ CH2 ~ C6U5CH2CH3 3 C6HsCH-GH2 ~ H2 2 (EqO 2) 3 During the last decade or so, however, benzene 4 and ethylene have experienced dramatic price increase. Ac-cordingly, in view of the above, the need has existed for an 6 effective commercial process for manufacturing ~tyrene, 7 which commends itself to a wide variety of co~mercial uses 8 such as the manufacture of synthe~ic rubbers and various 9 styrene-based plastics9 at a lower manufa~turing co$t than 10 conventional techniques known ~o the art. -~
11 It has now been discovered that, by taking a route 2 entirely different from conventional methods such as the 3 one de~cr~bed l~ Equation l or 2~ styrene can be p~oduced 4 at a far lower cast. I~ accordance with the present inven- -tion~ styrene is synthesized in four ma~or steps as follow~:
6 ' (a) oxidizing toluene in the presence of an oxidation cata-17 lyst to form an oxygenated product containing benzyl ace-18 ~ate; ~b) con~acting the oxygenated product formed in step 1q ~a) with a gaseous mixture containing carbon monoxide in the presence of a carbonylation catalyst and preferably a 21 halogen promoter to orm phenylacetic acid; (ç) hydr~gen- ~
2? ating the phenylacetic acid so produced in step `(b) in th~ -~3 presence of a hydrogenation ca~talyst to orm phenylethyL
24 alcohol, and (d) dehydrating the phenyl ethyl alcohol formed ~ -in s~ep (c) ko produce styrene. This novel reaction scheme . .
26 is further illustrated in the following equ~tion:
' ~-`'' ' , .
- ~ -- , .~ ~. . .
7~
~ CHO
~ .
benzyl aldehyde CO/H
CH3 CO/H2O ~ CH COOH
2 (Air)> ~ CH2-O-c-cH3 ~ > ~ O ~ 2 H~
J (a) oxida- ~ J ben~yl ace-tate (b) car- ~ ~ (c) hydro-",' tion ~ bonylation phenyl- genation toluene hydrolysis acetic ~ CH20H acid benzyl alcohol ~ CH2C~120H ~H=CH2 ~ (d) dahydration ~ :
phenylethyl Styrene (Eq. 3) alcohol As the first major step, toluene is contacted with air, oxygen or other oxygen sources, and acetic or propionic acid, in either the liquid or the vapor phase, in the presence of an oxidation catalyst and preferably a promoter at a temperature ranging from about 50 to about 400C., preferably from about 80 to about 300C., and more preferably from about 100 to about 200C. and at a pressure ranging from about 1 to about 50 atm., preerably from about 1 to about 30 atm., more preferably from about 1 to about 20 atm. to produce an oxygenated product con- -, .
taining about 0 to about 20 mole % benzyl aldehyde and about - 80 to 100 mole ~ benzyl acetate or benzyl propionate with the - overall conversion of about 50-100 mole % of toluene as follows~
~) .
5CE3 +~1~O2 +CH3COOH----~C6H5CH2--0-C-CH3 + C6H5CHO
~ + 2H2O (Eq- 4~
Variable-valent metals or compounds of variable-valent ;
' : ' :
: - 4 -1 ~ 8~
1 metals such as Tl, Te, Ce, Au, Bi, Pd, Sb, Mn, V, Ga, As, 2 Co, Cu, Se, Cr or Ag may be e~loyed either alone or in com-3 bination as the oxidation catalyst. Prefexred ca~alysts are 4 the organic and inorganic derivatives of Au, Bi, Tl, Ce, Sç, s Te and Pd. Specific examples o:E these preferred catalytic 6 compounds are inorganlc salts such as chlorides, bromides, 7 iodides, sulfates and nitrates; and organic salts such as 8 acetates and propionates o Au, Bi, Tl, Ce, Se, Te and Pd.
9 These variable-valent metals or their mixtures may be bene-ficially ~upported, especially in the case of the vapor phase oxidation, on such materials as SiO2, Al203, TiO2, 12 ZrO, MgO, acti~e carbon~ kieselg~hr, charcoal and the like.
13 As described in U~S. Patent 3,399,956 (Hirose et al,; 1968), 14 compounds of redox metals such as copper, mercury, chromium, manganese, iron, cobalt ~nd nickel may be prefersbly em-16 ployed, p~rticularly in the case of ~he liquid phasè oxi-17 dation~ alone or together with a halogen ion such as fluor~
18 ide,iodide, bromide or ch~oride in order to promote ~he cat~, 19 lytic e~fect of the variable-valent metallic salts. Xon-~ limiting representatives of such radox metallic d~rivat~ves 21 include inorganic and organic salts, e.g., iodides, bromide~, 22 chlorides, 02ides, nitrates, carbonates and sulfates, and 23 acetates a~d propionates9 o~ the metals lis~ed above. In ;~
24 addition, halides of Groups IA and IIA metals may aleo be beneficially employed as effective promoters for the oæida 26 tion catalystæ. These alkali metal and alkaline earth metal ~7 halides, e.g., chlorides, bromides, iodides and fluorides o~ -28 Li, N~, K, Be, Mg, Sr, B~ and Ca, are known to incre~se the 29 solubility o the v~riable-valent metallic salts in the ~ reaction medium.
: . '
- 5 -, .
7~ ~
I Optionally~ the acetic or propionic acid consumed 2 in the oxidation step represented by Equation 4 can be re-3 covered by hydrolyzing benzyl acetate or benzyl prop~onate ~I to form benzyl alcohol as follows:
5 C6H5cH20cocH3 ~ H20 -- ~ 6~5CH20H + CH3COOH
7~ ~
I Optionally~ the acetic or propionic acid consumed 2 in the oxidation step represented by Equation 4 can be re-3 covered by hydrolyzing benzyl acetate or benzyl prop~onate ~I to form benzyl alcohol as follows:
5 C6H5cH20cocH3 ~ H20 -- ~ 6~5CH20H + CH3COOH
6 (Eq- 5)
7 Acid catalysts which are commonly used in ester hydrolysis ~ -
8 can be employed to obtain a 90% or higher yield of benæyl al-~ cohol in ~he hydrolysis reaction represented by Equation 5.
Among such acid catalysts are included sulfuric acid, hydro ll chloric acid, nitric acid, chloric acid, benzene-sulfonic l~ acid, p-toluenesulfonic acid and cation exchange resin. Sul~
13 furic acid is most widely used. Reaction temperatures ~o be used in this hydrolysis of benzyl aceta~e range from about 5~ to about 300C~, preferably from about 7Q to 250C., 16 and`more preferably rom about 80 to about 200C. In order 17 to carry out the hydrolysis in the liquid phase at a given 1~ temperature, sufficient pressures, e.g., ranging from about 19 1 to about 30 a~m., should be maintained. The hydrolysis Of benzyl aceta~e makes it possible to recover acetic acid 21 for reuse in the oxidation step, thereby reducing the reac~or 22 requirement in the ensuing carbonylation step.
... .... .. .
23 As the second major step, benzyl aldehyde, benzyl 2~l acetate and/or benzyl alcohol derived from the oxidation of 2s toluene as discus~ed above are then carbonylated ~o form 26 phenylacetic acid in the liquid phase with carbon monoxide 27 or a gaseous mixture of hydrogen and carbon monoxide or car-28 bon monoixde with water as follows:
29 C6HsCH0 + ~0 + H2 ~ C6H5CH2COOH (Eq. 6) benzyl aldehyde phenylacetic acid ~ 7~
2 G6H5CH20H + CO -~ C6H5~H2COOH (Eq- 7) benzyl alcohol C6H5CH20COH3 -~ CO + H20----~C6H5CH2COOH + CH3COOH
4 benzyl acetate (Eq~ 8) Widely-known Group VIII metal carbo~ylation cataly~ts, e.g., 6 Co, Ni, Rh, Fe, Pd, Pt, Ir, may be employed with or without 7 a halogen promoter such as iodine, bromine or chlorine~
8 Rhodium or iridium ca~alyst promoted with the halogen ion
Among such acid catalysts are included sulfuric acid, hydro ll chloric acid, nitric acid, chloric acid, benzene-sulfonic l~ acid, p-toluenesulfonic acid and cation exchange resin. Sul~
13 furic acid is most widely used. Reaction temperatures ~o be used in this hydrolysis of benzyl aceta~e range from about 5~ to about 300C~, preferably from about 7Q to 250C., 16 and`more preferably rom about 80 to about 200C. In order 17 to carry out the hydrolysis in the liquid phase at a given 1~ temperature, sufficient pressures, e.g., ranging from about 19 1 to about 30 a~m., should be maintained. The hydrolysis Of benzyl aceta~e makes it possible to recover acetic acid 21 for reuse in the oxidation step, thereby reducing the reac~or 22 requirement in the ensuing carbonylation step.
... .... .. .
23 As the second major step, benzyl aldehyde, benzyl 2~l acetate and/or benzyl alcohol derived from the oxidation of 2s toluene as discus~ed above are then carbonylated ~o form 26 phenylacetic acid in the liquid phase with carbon monoxide 27 or a gaseous mixture of hydrogen and carbon monoxide or car-28 bon monoixde with water as follows:
29 C6HsCH0 + ~0 + H2 ~ C6H5CH2COOH (Eq. 6) benzyl aldehyde phenylacetic acid ~ 7~
2 G6H5CH20H + CO -~ C6H5~H2COOH (Eq- 7) benzyl alcohol C6H5CH20COH3 -~ CO + H20----~C6H5CH2COOH + CH3COOH
4 benzyl acetate (Eq~ 8) Widely-known Group VIII metal carbo~ylation cataly~ts, e.g., 6 Co, Ni, Rh, Fe, Pd, Pt, Ir, may be employed with or without 7 a halogen promoter such as iodine, bromine or chlorine~
8 Rhodium or iridium ca~alyst promoted with the halogen ion
9 is preferred. In addition, Group VIII me als complexed with -0 Group VA compounds such as phosphine, compounds of arsenic and anti ny, may also be beneff cially employ~d. Examp~eQ
12 of s~ch complexes may include the trialkylphosphites, the 13 tricycloalkylphosphites, the ~riarylphosphites, the ~ria~yI-4 phosphines, the triarylstibines, and the triarylargines of, for example, rhodium~ Acetic or propionic acid may be op~
6 tionally employed to provide an acidlc medium to facilitate 7 thc carbonylation. The volume ratio of H2/CO mi~ture em-18 ployed ranges from about 0/l00 to about 80/20, preferably 19 ~rom about 0/l00 to about 70/30, more preferably from about 5/95 to about 65/3~. This carbonylation can be carried out 21 at a temperature ranging from about 100 to about 300C~
22 preferably from about 150 to about 250C., and more prefer- -23 ~ ably ~rom about 150 to about 220C.; and a~ a pressur2 24 ran~ing from about l0 to about 350 atm~, preferably from i5 about 30 to about 300 atm.~ and more prefèrably~from abou~
26 30 to about 200 atm. A number of catalysts which are norm-27 ally used in deriving carboxylic acids from alcohols can be 28 employed in the in~tant carbonylation s~ep~ !s~ratio~s of these catalyst include the rhodium and the iridium metaLs, and ~heir inorganic and organic compounds such as bromides, : ', ' ~ '' ' -:
.; ' l iodides, chlorides, oxides, nitrates~ carbonates, and phenyl ;i ~ compounds. While a more detailed list of the ca~alytic com-3 pounds can be found in, for example, UOS~ Patent 3,813,428 4 (Paulik et al; 1974), specific compounds such as RhBr3, ~hI3, RhBr3 H209 Rh203, Rh(N03)3, Ir~C13~3H20, IrO2 and the like 6 can be beneficially employed~ It is known that the catalyti¢
7 effect of these rhodium or iridium compounds can be greatly 8 enhanced by the presence of a halogen moiety, e~g~, iodide, 9 chloride or bromide. Such compou~ds as hydrogen halide, al-kyl or a~yl halide, metallic halide and the halides of ammon-ll ium, phosphonium, arsonium and stibonium can be employed ~s ~ -12 the source of the halogen promoter.
l3 As the third major step toward the formation of 4 styrene, phenylacetic acid synthesized from benzyl acetate, --benzyl aldehyde and/or benzyl alcohol is then hydrogenated 16 in the liquid phase to form phenyl ethanol as follows: --l7 C6HsCH2cOoH ~ 2H2 ~ ~ C6HsCH2CH20H + a20 18 (Eq- 9) 19 This hydrogenation of phenylacetic acid can be conducte~ at temperatures between about 100 and 350C., preferably be-2l tween about 120 and about 330C~, and more preferably be-22 tween about 130 and about 300C., and at pressures bet~een 23 about 10 and about 400 atm., preferably between about 50 and 24 375 atm., and more preferably between about 100 and 350 atm.
in t~e presence of a hydrogenation catalyst A Cl-Cl2 alkyl 26 alcohol such as methanol, ethanol, propanol and bu~anol may 27 be employed as a promoterlsolvent. Group IIA metallic ions, 28 e.g. Ba+2, Ca+2 and an ammonium radical may also be em ployed a~ a promoter. Catalysts amenable ~o the insta~t hydrogenation step include ~he compounds of Cu, Groups VIB
~ .
8~
l and VIII metals such as Cr, Mo, W, Co, Ni and mixtures there-2 of r Non-limiting examples of these catalysts include sul-3 fides and oxides of Cu, and Groups VIB and VIII metals, ~ e.g., MoS, NiWS; copper oxide, chrDmium oxide, copper-chrom-ium oxide; and cobalt-molybdenum and copper-chromium metal-6 lic mixturesO In general, support materials such as alumin~, 7 alumina modified with other metallic oxides such as magnesia, ~ kieselguhr, pumice5 carbon, charcoal and silica are prefer-9 ably employed as the carrier of the metallic catalyst. A-o mong the preferred supported catalysts are copper-chromium ll impregnated in an alumina-magnesia carrier, i.e., Cu-Cr/
12 A1203~MgO and molybd~num-sulfur on charcoal~
13 In connection with the carbonylation and the hydro-~ genation steps, publications made by U S~ Bureau of Mines, e.g., I~ Wender et al~, "Homologation of Alcohols," JACS, l6 vol. 71 (1949), pp 4160-61, and another article by the same l7 authors, entitled "Chemistry o~ the Oxo and Related Reac-l8 tions IV. Reductions in the Aromatic Series," appearing l9 on pp. ?656-58 of JACS, vol. 73 (1951), suggest that phenyl-ethyl alcohol may be synthesized by direct homologation of 21 benzyl alcohol~ i.e., addition of a methylene group to benzyl 22~ alcohol. The articles, however, indicate a low yield of ?3 phenylethyl alcohol, e.g., 26%. Accordingly, if the yield 24 from the homologation can be sufficiently improved, e.g~, ;
above 50%, the second and the third steps described above 26 may be alternatively replaced with a homologation step.
27 AB the~fourth and last major step of the overall 28 process for the manufacture of s~yrene from toluene, phenyl ~ ethanol which is synthesized by hydrogenating phenylacetiç -acid as shown in Equation 9 is then dehydrated in the liquid ' : .
,: .
_ 9 _ ' :
, .. -, ~ ,~ . . . . .
1 or optionally in the vapor phaLse at a te~perature ranging 2 from about 100 to about 400~C., preferably from about 150C.
3 to about 350C., more preferably from about 180 to about 4 350C. and at pressures between about 0.2 and 70 atm., pre-ferably between about 1 and 35 atm., and more preferably be-6 tween about 1 and about 20 atm., in order to produce styrene 7 as follows:
C6H5CH2CH20H ~ C6H5CH-CH2 ~ H20 ~Eq. 10~
9 Although thermal, noncataly~ic dehydrations are pos~ible at elevated temperatures impro~ed re~ults can be obtained by -11 employing various dehydration catàlysts known to the ar~.
12 For example, metallic oxides such as titanium, thorium or 13 aluminum oxide may be ben~ficially used. The dehydration 14 of phenyl e~hanol can also be carried out in an inert liquid i5 ~ medium in the presence of an scid and/or a so-called high- -16 surface-area solid dehydration catalyst. Representatives o 17 preferred acid catalysts include a variety of mineral acids 18 such as sulfuric acid, perchloric acid and phosphoric acid;
19 carboxylic acids such as oxalic acid and salicylic acid;
and also such acids as p-toluene-sulphonic acid a~d other ~l aryl sulphonic acids of benzene and its homologs. Sui~able 22 high-surface-area catalys~s are ac~iva~ed carbo~, natural ~ -23 clays, molecular sieves, silica-aluminas and activated alum-24 inas. The term, high-surface-area catalyst, is, as defined -~
~5 in U.S. pa~ent 3,526,674 (Becker et al; 1970), used ~o mea~
26 a catAlys~ having a surface at least in excess of about 15 27 sq. meters per gram of t~e catalyst. A large number of or-28 ganic material can be employed to provide a suitable liquid reaction medium. Some of the suitable materials, as dis-closed in the Becker patent, include high boiling hydrocar- -- .
.::
'~,
12 of s~ch complexes may include the trialkylphosphites, the 13 tricycloalkylphosphites, the ~riarylphosphites, the ~ria~yI-4 phosphines, the triarylstibines, and the triarylargines of, for example, rhodium~ Acetic or propionic acid may be op~
6 tionally employed to provide an acidlc medium to facilitate 7 thc carbonylation. The volume ratio of H2/CO mi~ture em-18 ployed ranges from about 0/l00 to about 80/20, preferably 19 ~rom about 0/l00 to about 70/30, more preferably from about 5/95 to about 65/3~. This carbonylation can be carried out 21 at a temperature ranging from about 100 to about 300C~
22 preferably from about 150 to about 250C., and more prefer- -23 ~ ably ~rom about 150 to about 220C.; and a~ a pressur2 24 ran~ing from about l0 to about 350 atm~, preferably from i5 about 30 to about 300 atm.~ and more prefèrably~from abou~
26 30 to about 200 atm. A number of catalysts which are norm-27 ally used in deriving carboxylic acids from alcohols can be 28 employed in the in~tant carbonylation s~ep~ !s~ratio~s of these catalyst include the rhodium and the iridium metaLs, and ~heir inorganic and organic compounds such as bromides, : ', ' ~ '' ' -:
.; ' l iodides, chlorides, oxides, nitrates~ carbonates, and phenyl ;i ~ compounds. While a more detailed list of the ca~alytic com-3 pounds can be found in, for example, UOS~ Patent 3,813,428 4 (Paulik et al; 1974), specific compounds such as RhBr3, ~hI3, RhBr3 H209 Rh203, Rh(N03)3, Ir~C13~3H20, IrO2 and the like 6 can be beneficially employed~ It is known that the catalyti¢
7 effect of these rhodium or iridium compounds can be greatly 8 enhanced by the presence of a halogen moiety, e~g~, iodide, 9 chloride or bromide. Such compou~ds as hydrogen halide, al-kyl or a~yl halide, metallic halide and the halides of ammon-ll ium, phosphonium, arsonium and stibonium can be employed ~s ~ -12 the source of the halogen promoter.
l3 As the third major step toward the formation of 4 styrene, phenylacetic acid synthesized from benzyl acetate, --benzyl aldehyde and/or benzyl alcohol is then hydrogenated 16 in the liquid phase to form phenyl ethanol as follows: --l7 C6HsCH2cOoH ~ 2H2 ~ ~ C6HsCH2CH20H + a20 18 (Eq- 9) 19 This hydrogenation of phenylacetic acid can be conducte~ at temperatures between about 100 and 350C., preferably be-2l tween about 120 and about 330C~, and more preferably be-22 tween about 130 and about 300C., and at pressures bet~een 23 about 10 and about 400 atm., preferably between about 50 and 24 375 atm., and more preferably between about 100 and 350 atm.
in t~e presence of a hydrogenation catalyst A Cl-Cl2 alkyl 26 alcohol such as methanol, ethanol, propanol and bu~anol may 27 be employed as a promoterlsolvent. Group IIA metallic ions, 28 e.g. Ba+2, Ca+2 and an ammonium radical may also be em ployed a~ a promoter. Catalysts amenable ~o the insta~t hydrogenation step include ~he compounds of Cu, Groups VIB
~ .
8~
l and VIII metals such as Cr, Mo, W, Co, Ni and mixtures there-2 of r Non-limiting examples of these catalysts include sul-3 fides and oxides of Cu, and Groups VIB and VIII metals, ~ e.g., MoS, NiWS; copper oxide, chrDmium oxide, copper-chrom-ium oxide; and cobalt-molybdenum and copper-chromium metal-6 lic mixturesO In general, support materials such as alumin~, 7 alumina modified with other metallic oxides such as magnesia, ~ kieselguhr, pumice5 carbon, charcoal and silica are prefer-9 ably employed as the carrier of the metallic catalyst. A-o mong the preferred supported catalysts are copper-chromium ll impregnated in an alumina-magnesia carrier, i.e., Cu-Cr/
12 A1203~MgO and molybd~num-sulfur on charcoal~
13 In connection with the carbonylation and the hydro-~ genation steps, publications made by U S~ Bureau of Mines, e.g., I~ Wender et al~, "Homologation of Alcohols," JACS, l6 vol. 71 (1949), pp 4160-61, and another article by the same l7 authors, entitled "Chemistry o~ the Oxo and Related Reac-l8 tions IV. Reductions in the Aromatic Series," appearing l9 on pp. ?656-58 of JACS, vol. 73 (1951), suggest that phenyl-ethyl alcohol may be synthesized by direct homologation of 21 benzyl alcohol~ i.e., addition of a methylene group to benzyl 22~ alcohol. The articles, however, indicate a low yield of ?3 phenylethyl alcohol, e.g., 26%. Accordingly, if the yield 24 from the homologation can be sufficiently improved, e.g~, ;
above 50%, the second and the third steps described above 26 may be alternatively replaced with a homologation step.
27 AB the~fourth and last major step of the overall 28 process for the manufacture of s~yrene from toluene, phenyl ~ ethanol which is synthesized by hydrogenating phenylacetiç -acid as shown in Equation 9 is then dehydrated in the liquid ' : .
,: .
_ 9 _ ' :
, .. -, ~ ,~ . . . . .
1 or optionally in the vapor phaLse at a te~perature ranging 2 from about 100 to about 400~C., preferably from about 150C.
3 to about 350C., more preferably from about 180 to about 4 350C. and at pressures between about 0.2 and 70 atm., pre-ferably between about 1 and 35 atm., and more preferably be-6 tween about 1 and about 20 atm., in order to produce styrene 7 as follows:
C6H5CH2CH20H ~ C6H5CH-CH2 ~ H20 ~Eq. 10~
9 Although thermal, noncataly~ic dehydrations are pos~ible at elevated temperatures impro~ed re~ults can be obtained by -11 employing various dehydration catàlysts known to the ar~.
12 For example, metallic oxides such as titanium, thorium or 13 aluminum oxide may be ben~ficially used. The dehydration 14 of phenyl e~hanol can also be carried out in an inert liquid i5 ~ medium in the presence of an scid and/or a so-called high- -16 surface-area solid dehydration catalyst. Representatives o 17 preferred acid catalysts include a variety of mineral acids 18 such as sulfuric acid, perchloric acid and phosphoric acid;
19 carboxylic acids such as oxalic acid and salicylic acid;
and also such acids as p-toluene-sulphonic acid a~d other ~l aryl sulphonic acids of benzene and its homologs. Sui~able 22 high-surface-area catalys~s are ac~iva~ed carbo~, natural ~ -23 clays, molecular sieves, silica-aluminas and activated alum-24 inas. The term, high-surface-area catalyst, is, as defined -~
~5 in U.S. pa~ent 3,526,674 (Becker et al; 1970), used ~o mea~
26 a catAlys~ having a surface at least in excess of about 15 27 sq. meters per gram of t~e catalyst. A large number of or-28 ganic material can be employed to provide a suitable liquid reaction medium. Some of the suitable materials, as dis-closed in the Becker patent, include high boiling hydrocar- -- .
.::
'~,
- 10 ~
- ~ , . .: .
1 bons, high-boiling petroleum distillates, mineral oils and 2 various high-boiling polar materials. One of the preferred 3 solvents is the high-boiling residue formed during the de-4 hydration reaction. In addition, it is also desirable to s employ low-boiling organic compounds such as methanol, 6 acetic acid, t-butyl alcohol a~d the like. The use of such 7 low-boiling solvents is preferred since they tend to mini-~ mize the polymerization of styrene.
9 The present invention $urther provides an economic method of separating and recovering the phenylacetic acid
- ~ , . .: .
1 bons, high-boiling petroleum distillates, mineral oils and 2 various high-boiling polar materials. One of the preferred 3 solvents is the high-boiling residue formed during the de-4 hydration reaction. In addition, it is also desirable to s employ low-boiling organic compounds such as methanol, 6 acetic acid, t-butyl alcohol a~d the like. The use of such 7 low-boiling solvents is preferred since they tend to mini-~ mize the polymerization of styrene.
9 The present invention $urther provides an economic method of separating and recovering the phenylacetic acid
11 formed at the carbonylation step fro~ the carbonylation cat~-
12 lyst and the carbonylation promoter, i.e., a rhodium or ~3 iridium compound and a halogen promoter. This in~entive em-4 bodiment not only makes it possible to obtain highly purified 'phenylacetic acid but also offers a surprisingly effective 16 means of minimizing the loss of expensive catalyst metals9 17 thereby making the entire process more economically feasible~
18 In accordance with this inventive embodiment~ th~ carbonyla--19 tion product mix~ure containing the phenylacetic''acid3 the " -~ halogen pro ter and the carbonylation catalys~ is irst 21 sent to a separation chamber'of a series of separation ch~m-22 bers in order ~o separate gaseous ~ompounds, e.g~, synthesis 23 gas mixture ~nd other low-boiling compounds, from liquid 24 compounds, e.g., solvent, halogen promoter, rhodium or irld~
- 25 ium compound and phenylacetic acid The synthesis gas mix-26 ture recovered as the tops ef1uent from the separation 27 chamber(s), whi~h may contain traees of halogen moieties '~' 28 and solven~, is first scrubbed with the carbonylation feed-stream conta-.Lning benzyl acetate, benzyl aldehyde and/or benzyl alcohol, and is then recycled to the carbonylation ':
.
7~
I reactor for reuse. The liquicl-phase mixture, discharged as 2 the bottoms effluent from the separation chamber(s), is then 3 collected and chilled to the melting point or to a tempera-~l ture slightly below ~he melting point of phenylacetic acidJ
e.g.9 about 75C. at one atmospheric pressure, in order to crystallize the phenylacetic acid. This crystallization 7 results in the following liquid-solid phase separation: the ~ liquid phase containing the catalyst, the promoter and the 9 solvent; and the solid phase containing mainly the phenyl-0 acetic acid. The crystalline product, if necessary9 is then 11 washed with a solvent, e.g., acetic or propionic acid, or a iquid mixture of the carbonylation reactants, e.g., benzyl
18 In accordance with this inventive embodiment~ th~ carbonyla--19 tion product mix~ure containing the phenylacetic''acid3 the " -~ halogen pro ter and the carbonylation catalys~ is irst 21 sent to a separation chamber'of a series of separation ch~m-22 bers in order ~o separate gaseous ~ompounds, e.g~, synthesis 23 gas mixture ~nd other low-boiling compounds, from liquid 24 compounds, e.g., solvent, halogen promoter, rhodium or irld~
- 25 ium compound and phenylacetic acid The synthesis gas mix-26 ture recovered as the tops ef1uent from the separation 27 chamber(s), whi~h may contain traees of halogen moieties '~' 28 and solven~, is first scrubbed with the carbonylation feed-stream conta-.Lning benzyl acetate, benzyl aldehyde and/or benzyl alcohol, and is then recycled to the carbonylation ':
.
7~
I reactor for reuse. The liquicl-phase mixture, discharged as 2 the bottoms effluent from the separation chamber(s), is then 3 collected and chilled to the melting point or to a tempera-~l ture slightly below ~he melting point of phenylacetic acidJ
e.g.9 about 75C. at one atmospheric pressure, in order to crystallize the phenylacetic acid. This crystallization 7 results in the following liquid-solid phase separation: the ~ liquid phase containing the catalyst, the promoter and the 9 solvent; and the solid phase containing mainly the phenyl-0 acetic acid. The crystalline product, if necessary9 is then 11 washed with a solvent, e.g., acetic or propionic acid, or a iquid mixture of the carbonylation reactants, e.g., benzyl
13 acetate, benzyl aldehyde and/or benzyl alcohol, in order to
14 remove rhodium or iridium moieties remaining in the crystal-line substance Further, if desired, the crystalline pro-6 duct may be remelted, recrystallized and washed in order to maximize the purity of the phenylacetic acid separated and 18 also minimize the catalyst loss. The liquid mixture contain-lq ing ~he catalyst and the solvent recovered ~rom this l~quid-solid phase separation s~ep may be recycled to the carbonyl~
21 ation reactor ~or reuse. The crystalline phenylacetic acid 22 so recovered may be then remelted or dissolved in a Cl-C
23 alkyl alcohol and hydrogenated in accordance with the in-24 stant invention.
25 EXAMPLE 1 ~ ~-~26 - This example is intended to demonstrate that about 27 99% of reacted toluene can be converted in the liquid phase 2~ to the desired oxygenated toluene derivatives.
29 A one-liter ~lask is charged with 450 grams o ~ acetic acid, ~2 grams of ~oluene and a catalyst mix~ure con-:
...~ . , , i .. ~ . ~ . . .... .
~8:~'7~4 l taining 34.1 grams of 5 wt. % palladium on charcoal, 100 2 grams of KOAc and 14 grams of stannous acetate. While the 3 flask containing the reaction mixture is constantly stirred 4 at about 100C., air is contilluously blown through the reac-tion mixture at a rate of about 0.5 liter/min~ measured at 6 25C. and 760 mm Hg for about 9 hours. About 80 mol % af 7 toluene is converted to form approximately 91.5 mol % of n benzyl acetate, 7.5 mol % of benzyl aldehyde and 1 mol % of 9 benzyl diacetate.
ll This example is designed to show that about 90 -12 mole % of toluene reacted can be converted to benæyl acetate l3 by carrying out the oxidation of toluene in the vapor phase.
14 A mixture of 70 7 wt. % acetic acid, 23.2 wt. %
toluene and 6.1 wt~ % water was first, at the rate of 0.198 16 gm/min O ~ vaporized and then fed into a 3/8" I.D. stainless-17 steel tubular reactor packed with about 4.7 gm. of palladium 1a on alumina support, at 160-170C. and about 30 pslg. The 19 palladium content contained in the supported catalyst was about 2% by weight. After about two hours of continuously 2l running the reaction, the gaseous reaction product was di-22 rectly sent to an on-line G.C. analyzer. The G.C. analysis 23 showed tha~ about 15% of toluene was converted; and that no 24 product other than benzyl acetate was ~ormed from the vapor phase reaction. A check based on the feed/product ma~erial 26 balance indicated that the yield of benzyl acetate was over 2~ go mole % of toluene reacted.
29 This example is intended to show that about 90 mol ~ of benzyl alcohol derive~ from the oxidation of toluene , . ., , ~.
1 can be converted to phenylacet:ic acid.
2 A batch autoclave is charg~d with 213 grams of 3 acetic acid, 108 grams of benzyl alcohol, 0.428 grams of 4 RhC13 3H20 and an aqueous promoter containing 57 wt. % of hydriodic acid (HI~. The autoclave is pressurized with CO
6 to 1,000 psig at 175C until the complete conversion of the 7 benzyl alcohol charged takes place. The selectivity to 8 phenylacetic acid is about 90 mol %O
This example is designed to demonstrate that about 11 91 mol % of benzyl aceta~e can be hydroformylated to form de-12 sirable compounds, i.e., phenylacetic acid and dibenzyl 13 ether Dibenzyl ether so formed can be recycled to the car- -14 bonylation step. --lS An autoclave was charged with 100 grams of benzyl 16 ace~ate, 0.25 gram of aqueous rhodium oxide and 1 gram of 17 iodine. The batch reactor was then pressurized with a syn 18 gas mixture having the volume ratio of H2/CO=60l40 to 1,000 1~ psig at 150DC- The hydroformylation was continued at con~
stant pressure for about 3 hours. The final product was 21 found to contain about 22 mol % of phenylacetic acid and 22 about 69 mol % of dibenzyl ether which can be further carbon-23 ylated to form phenylacetic acid as shown in Example S.
Th-ls example i~ designed to demonstrate that benzyl ~ -`
26 alcohol can be carbonylated by employing a synthesi~ gas to 27 produce a high yield, e.g., abou~ 90% based on benzyl alco-28 hol charged, of phenylacetic acid; and that dibenzyl ether ~ and benzylphenyl acetate may be ormed as precursors ~o phenylacetic acid.
.
.
.. . ~ , . .
8 ~
1 To the same autoclave employed in Example 4 were 2 introduced 30 grams of benzyl alcohol, 0~1 gram of rhodium 3 oxide and 0.3 gram of iodine. The autoclave was then pres-4 surized with a synthesis gas mixture containing about 60 vol % hydrogen and about 40 vol~ % C0 to about 1,000 psig.
6 at about 125C for one hour. G. C. analysis of the reac~ion 7 sample at the moment indicated that about 87~6 mol % of the 8 benzyl alcohol introduced was converted to: 11.1 mol % of 9 phenylacetic acid, 26.5 mol % of dibenzyl ether, 58.1 mol %
lo benzylphenyl acetate and 2.3 mol % of toluene. The carbonyl 11 ation, under the same synthesis gas pressure and the tempera-2 ture, i.e.~ 1,000 psig. and 125C., was then continued for 13 two additional hours. G.C. analysis of the three-hour re-14 action product showed that essentially all o the benzyl al-cohol, dibenzyl ether and about 90% of the benzylphenyl ace~
6 tate which had been detected in the one-hour reaction pro-7 duct were converted to phenylacetic acid, producing phenyl-18 acetic acid in a yield higher than 90% based on benzyl alco-9 hol charged.
~ EXAMPLE 6 21 This example is designed to show that benzyl alde- -22 hyde can be hydroformylated to form phenylacetic acid.
23 ; To the same autoclave employed in Example 4 were 24 introduced 30 grams of benzyl aldehyde, 0.1 gram of rhodium ~5 oxide and 0.3 gram of iodine. The autocLave was ~hen pres-26 surized wlth a synthesis gas mixture having the volume ratio 27 of H2/Co=60t40 to 1,000 psig and 150C.; and was maintained 28 at the operating conditions for about 3 hours. G.C. Analysis of ~he final product indicated that about 70 mol % of ~he benzyl aldehyde was conver~ed to yield 73.3 mol % of p~enyl~
,:
21 ation reactor ~or reuse. The crystalline phenylacetic acid 22 so recovered may be then remelted or dissolved in a Cl-C
23 alkyl alcohol and hydrogenated in accordance with the in-24 stant invention.
25 EXAMPLE 1 ~ ~-~26 - This example is intended to demonstrate that about 27 99% of reacted toluene can be converted in the liquid phase 2~ to the desired oxygenated toluene derivatives.
29 A one-liter ~lask is charged with 450 grams o ~ acetic acid, ~2 grams of ~oluene and a catalyst mix~ure con-:
...~ . , , i .. ~ . ~ . . .... .
~8:~'7~4 l taining 34.1 grams of 5 wt. % palladium on charcoal, 100 2 grams of KOAc and 14 grams of stannous acetate. While the 3 flask containing the reaction mixture is constantly stirred 4 at about 100C., air is contilluously blown through the reac-tion mixture at a rate of about 0.5 liter/min~ measured at 6 25C. and 760 mm Hg for about 9 hours. About 80 mol % af 7 toluene is converted to form approximately 91.5 mol % of n benzyl acetate, 7.5 mol % of benzyl aldehyde and 1 mol % of 9 benzyl diacetate.
ll This example is designed to show that about 90 -12 mole % of toluene reacted can be converted to benæyl acetate l3 by carrying out the oxidation of toluene in the vapor phase.
14 A mixture of 70 7 wt. % acetic acid, 23.2 wt. %
toluene and 6.1 wt~ % water was first, at the rate of 0.198 16 gm/min O ~ vaporized and then fed into a 3/8" I.D. stainless-17 steel tubular reactor packed with about 4.7 gm. of palladium 1a on alumina support, at 160-170C. and about 30 pslg. The 19 palladium content contained in the supported catalyst was about 2% by weight. After about two hours of continuously 2l running the reaction, the gaseous reaction product was di-22 rectly sent to an on-line G.C. analyzer. The G.C. analysis 23 showed tha~ about 15% of toluene was converted; and that no 24 product other than benzyl acetate was ~ormed from the vapor phase reaction. A check based on the feed/product ma~erial 26 balance indicated that the yield of benzyl acetate was over 2~ go mole % of toluene reacted.
29 This example is intended to show that about 90 mol ~ of benzyl alcohol derive~ from the oxidation of toluene , . ., , ~.
1 can be converted to phenylacet:ic acid.
2 A batch autoclave is charg~d with 213 grams of 3 acetic acid, 108 grams of benzyl alcohol, 0.428 grams of 4 RhC13 3H20 and an aqueous promoter containing 57 wt. % of hydriodic acid (HI~. The autoclave is pressurized with CO
6 to 1,000 psig at 175C until the complete conversion of the 7 benzyl alcohol charged takes place. The selectivity to 8 phenylacetic acid is about 90 mol %O
This example is designed to demonstrate that about 11 91 mol % of benzyl aceta~e can be hydroformylated to form de-12 sirable compounds, i.e., phenylacetic acid and dibenzyl 13 ether Dibenzyl ether so formed can be recycled to the car- -14 bonylation step. --lS An autoclave was charged with 100 grams of benzyl 16 ace~ate, 0.25 gram of aqueous rhodium oxide and 1 gram of 17 iodine. The batch reactor was then pressurized with a syn 18 gas mixture having the volume ratio of H2/CO=60l40 to 1,000 1~ psig at 150DC- The hydroformylation was continued at con~
stant pressure for about 3 hours. The final product was 21 found to contain about 22 mol % of phenylacetic acid and 22 about 69 mol % of dibenzyl ether which can be further carbon-23 ylated to form phenylacetic acid as shown in Example S.
Th-ls example i~ designed to demonstrate that benzyl ~ -`
26 alcohol can be carbonylated by employing a synthesi~ gas to 27 produce a high yield, e.g., abou~ 90% based on benzyl alco-28 hol charged, of phenylacetic acid; and that dibenzyl ether ~ and benzylphenyl acetate may be ormed as precursors ~o phenylacetic acid.
.
.
.. . ~ , . .
8 ~
1 To the same autoclave employed in Example 4 were 2 introduced 30 grams of benzyl alcohol, 0~1 gram of rhodium 3 oxide and 0.3 gram of iodine. The autoclave was then pres-4 surized with a synthesis gas mixture containing about 60 vol % hydrogen and about 40 vol~ % C0 to about 1,000 psig.
6 at about 125C for one hour. G. C. analysis of the reac~ion 7 sample at the moment indicated that about 87~6 mol % of the 8 benzyl alcohol introduced was converted to: 11.1 mol % of 9 phenylacetic acid, 26.5 mol % of dibenzyl ether, 58.1 mol %
lo benzylphenyl acetate and 2.3 mol % of toluene. The carbonyl 11 ation, under the same synthesis gas pressure and the tempera-2 ture, i.e.~ 1,000 psig. and 125C., was then continued for 13 two additional hours. G.C. analysis of the three-hour re-14 action product showed that essentially all o the benzyl al-cohol, dibenzyl ether and about 90% of the benzylphenyl ace~
6 tate which had been detected in the one-hour reaction pro-7 duct were converted to phenylacetic acid, producing phenyl-18 acetic acid in a yield higher than 90% based on benzyl alco-9 hol charged.
~ EXAMPLE 6 21 This example is designed to show that benzyl alde- -22 hyde can be hydroformylated to form phenylacetic acid.
23 ; To the same autoclave employed in Example 4 were 24 introduced 30 grams of benzyl aldehyde, 0.1 gram of rhodium ~5 oxide and 0.3 gram of iodine. The autocLave was ~hen pres-26 surized wlth a synthesis gas mixture having the volume ratio 27 of H2/Co=60t40 to 1,000 psig and 150C.; and was maintained 28 at the operating conditions for about 3 hours. G.C. Analysis of ~he final product indicated that about 70 mol % of ~he benzyl aldehyde was conver~ed to yield 73.3 mol % of p~enyl~
,:
- 15 - ~
~ ~ 8 ~ ~ ~ 4 1 acetic acid, 7.1 mol ~/O of tol~ene and 19.6 mol % of heavy-2 boiling product which was mainly dibenzyl ether 4 This example is designed to show that a high yield, ~.g., about 95.2 mol %, of ph~!nyl ethanol can be obtained 6 from the hydrogenation of phenylacetic acidO
7 A 50 c.c. volume batch reactor was charged with 20 8 grams of phenylacetic acid (0.147 mole~, 30 grams o~ ethanol, 9 and 5 grams of molybdenum-sulfur on charcoal as catalyst.
lo This reactor was then pressurized with hydrogen to 3,000 psig 11 at 300C. for about 8 hours. G.C~ analysis of the product 12 showed that 17.1 grams (0.140 mole) of phenyl ethanol was 13 formed~ Another product was identified as ethylbenzene.
14 The selectivity to phenyl ethanol was about 95~2 mol %. ;~
EXAMæLE 8 .... _.
~ ~ 8 ~ ~ ~ 4 1 acetic acid, 7.1 mol ~/O of tol~ene and 19.6 mol % of heavy-2 boiling product which was mainly dibenzyl ether 4 This example is designed to show that a high yield, ~.g., about 95.2 mol %, of ph~!nyl ethanol can be obtained 6 from the hydrogenation of phenylacetic acidO
7 A 50 c.c. volume batch reactor was charged with 20 8 grams of phenylacetic acid (0.147 mole~, 30 grams o~ ethanol, 9 and 5 grams of molybdenum-sulfur on charcoal as catalyst.
lo This reactor was then pressurized with hydrogen to 3,000 psig 11 at 300C. for about 8 hours. G.C~ analysis of the product 12 showed that 17.1 grams (0.140 mole) of phenyl ethanol was 13 formed~ Another product was identified as ethylbenzene.
14 The selectivity to phenyl ethanol was about 95~2 mol %. ;~
EXAMæLE 8 .... _.
16 Example 8 is designed to illustrate that styrene
17 can be obtained in high yields by dehydrating phènyle~hyl
18 alcohol.
19 Phenylethyl alcohol was introduced, at a rate of ~`~
1.38 gm~/min., into a one-inch O.D. stainless-steel ~ubular 21 reactor packed wi~h 162 c.c. of aluminum catalyst (Alcoa ~- -22 15L). The reactor9 which was operated at 345C~, was al~o 23 charged wi~h nitrogen at the rate o~ about one s~andard cu.
24 ft~/hr~ G.C. analysis of the dehydration produc~ showed .
that over 98DL of the phenyl ethanol introduced was converted ~` ~6 to fonm: 94.0 mol 7O of styrene, 0.8 mol % of ethylbenzene 27 and traces of toluene and diphenylethyl ether. Accordingly, - ~8 the yield of styrene based on phenyl ethanol reacted was ~ ~ about 95.6%. `
.. .
.:
- ~ - 16
1.38 gm~/min., into a one-inch O.D. stainless-steel ~ubular 21 reactor packed wi~h 162 c.c. of aluminum catalyst (Alcoa ~- -22 15L). The reactor9 which was operated at 345C~, was al~o 23 charged wi~h nitrogen at the rate o~ about one s~andard cu.
24 ft~/hr~ G.C. analysis of the dehydration produc~ showed .
that over 98DL of the phenyl ethanol introduced was converted ~` ~6 to fonm: 94.0 mol 7O of styrene, 0.8 mol % of ethylbenzene 27 and traces of toluene and diphenylethyl ether. Accordingly, - ~8 the yield of styrene based on phenyl ethanol reacted was ~ ~ about 95.6%. `
.. .
.:
- ~ - 16
Claims (20)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the manufacture of styrene which comprises:
(a) oxidizing toluene in the presence of an oxidation catalyst, and acetic acid or propionic acid to form an oxygenated pro-duct containing benzyl acetate or benzyl propionate;
(b) contacting the oxygenated product formed in step (a) with a gaseous mixture contain-ing carbon monoxide in the presence of a carbonylation catalyst to form phenylacetic acid;
(c) hydrogenating the phenylacetic acid formed in step (b) in the presence of a hydrogena-tion catalyst to form phenylethyl alcohol;
and (d) dehydrating the phenylethyl alcohol formed in step (c) to form styrene.
(a) oxidizing toluene in the presence of an oxidation catalyst, and acetic acid or propionic acid to form an oxygenated pro-duct containing benzyl acetate or benzyl propionate;
(b) contacting the oxygenated product formed in step (a) with a gaseous mixture contain-ing carbon monoxide in the presence of a carbonylation catalyst to form phenylacetic acid;
(c) hydrogenating the phenylacetic acid formed in step (b) in the presence of a hydrogena-tion catalyst to form phenylethyl alcohol;
and (d) dehydrating the phenylethyl alcohol formed in step (c) to form styrene.
2. A process according to claim 1 which comprises:
(a) oxidizing toluene in the presence of (i) a variable-valent metallic catalyst; (ii) a redox metallic promoter; (iii) a halogen ion;
and (iv) acetic acid or propionic acid to form an oxygenated product containing benzyl acetate or benzyl propionate;
(b) contacting the oxygenated product formed in step (a) with a gaseous mixture containing carbon monoxide in the presence of a Group VIII metallic catalyst, and a halogen pro-moter to form phenylacetic acid;
(c) hydrogenating the phenylacetic acid formed instep (b) in the presence of a hydrogen-ation catalyst selected from the group con-sisting of copper, Group VIB and Group VIII
metals and mixtures thereof, and a C1-C12 alkyl alcohol to form phenylethyl alcohol;
and (d) dehydrating the phenylethyl alcohol formed in step (c) to form styrene.
(a) oxidizing toluene in the presence of (i) a variable-valent metallic catalyst; (ii) a redox metallic promoter; (iii) a halogen ion;
and (iv) acetic acid or propionic acid to form an oxygenated product containing benzyl acetate or benzyl propionate;
(b) contacting the oxygenated product formed in step (a) with a gaseous mixture containing carbon monoxide in the presence of a Group VIII metallic catalyst, and a halogen pro-moter to form phenylacetic acid;
(c) hydrogenating the phenylacetic acid formed instep (b) in the presence of a hydrogen-ation catalyst selected from the group con-sisting of copper, Group VIB and Group VIII
metals and mixtures thereof, and a C1-C12 alkyl alcohol to form phenylethyl alcohol;
and (d) dehydrating the phenylethyl alcohol formed in step (c) to form styrene.
3. The process of claim 2 wherein the variable-valent metallic catalyst employed in step (a) is selected from the group consisting of thallium, tellurium, cerium, gold, bismuth, palladium, antimony, manganese, vanadium, gallium, arsenic, cobalt, copper, selenium, chromium, silver, and mixtures thereof.
4. The process of claim 3 wherein thc redox metallic promoter employed in step (a) is selected from the group consisting of copper, mercury, chromium, manganese, iron, cobalt and nickel.
5. The process of claim 4 wherein the oxida-tion of said toluene in step (a) is conducted in the pres-ence of a metallic halide selected from the group consisting of the halides of Group IA and Group IIA metals.
6. The process of claim 5 wherein the oxida-tion of said toluene in step (a) is conducted at a tempera-ture within the range of from about 50° to about 400°C. and at a pressure within the range of from about 1 to about 50 atm.
7. The process of claim 6 wherein the benzyl acetate or benzyl propionate formed in step (a) is hydro-lyzed to form benzyl alcohol and wherein said benzyl alco-hol is then carbonylated in step (b).
8. The process of claim 7 wherein said hydroly-sis is conducted at a temperature within the range of from about 60° to about 300°C. and at a pressure within the range of from about 1 to about 30 atm. and in the presence of a hydrolysis catalyst selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, chloric acid, benzenesulfonic acid, p-toluenesulfonic acid and a cation exchange resin.
9. The process of claim 1 wherein said gaseous mixture employed in step (b) contains carbon monoxide and hydrogen.
10. The process of claim 1 wherein said con-tacting in step (b) is conducted in the presence of water.
11. The process of claim 1 wherein the carbony-lation catalyst employed in step (b) is selected from the group consisting of cobalt, nickel, rhodium, iron, palladium, platinum and iridium.
12. The process of claim 2 wherein the carbon-ylation of the oxygenated product in step (b) is conducted in the presence of a carbonylation catalyst selected from the group consisting of rhodium and iridium and a halogen promoter selected from the group consisting of bromine, chlorine and iodine.
13. The process of claim 1 wherein the car-bonylation of the oxygenated product in step (b) is con-ducted at a temperature within the range of from about 100°
to about 300°C. and at a pressure within the range of from about 10 to about 350 atm.
to about 300°C. and at a pressure within the range of from about 10 to about 350 atm.
14. The process of claim 1 wherein the hydro-genation catalyst employed in s tep (c) is selected from the group consisting of copper, chromium, molybdenum, tungsten, cobalt, nickel and mixtures thereof.
15. The process of claim 14 wherein the hydrogen-ation catalyst is supported on a carrier selected from the group consisting of alumina, magnesia, alumina modified with magnesia, kieselguhr, pumice, carbon, charcoal and silica.
16. The process of claim 1 wherein the hydro-genation catalyst is a copper-chromium mixture supported on an alumina-magnesia carrier.
17. The process of claim 1 wherein the hydro-genation of the phenylacetic acid is conducted in the pres-ence of a promoter selected from the group consisting of Group IIA metallic ions and an ammonium radical.
18. The process of claim 1 wherein the hydro-genation of the phenylacetic acid in step (c) is conducted at a temperature within the range of from about 100° to about 350°C. and at a pressure within the range of from about 10 to about 400 atm.
19. The process of claim 1 wherein the dehydra-tion of the phenylethyl alcohol in step (d) is conducted in the presence of a high-surface-area catalyst selected from the group consisting of activated carbon, natural clays, molecular sieves, silica-aluminas and activated aluminas.
20. The process of claim 1 wherein the car-bonylation catalyst employed in step (b) is recovered from the phenylacetic acid formed in step (b) by:
(1) separating the gaseous mixture containing carbon monoxide from the liquid mixture contain-ing the phenylacetic acid and the carbonylation catalyst;
(2) lowering the temperature of the liquid mix-ture, separated in step (1), containing the phenyl-acetic acid and the carbonylation catalyst to a temperature not higher than the melting point of the phenylacetic acid in order to crystallize sub-stantially all of the phenylacetic acid contained in the liquid mixture; and, thereafter, (3) separating the crystalline phenylacetic acid formed in step (2) from the liquid mixture, there-by recovering the carbonylation catalyst remaining in the liquid mixture.
(1) separating the gaseous mixture containing carbon monoxide from the liquid mixture contain-ing the phenylacetic acid and the carbonylation catalyst;
(2) lowering the temperature of the liquid mix-ture, separated in step (1), containing the phenyl-acetic acid and the carbonylation catalyst to a temperature not higher than the melting point of the phenylacetic acid in order to crystallize sub-stantially all of the phenylacetic acid contained in the liquid mixture; and, thereafter, (3) separating the crystalline phenylacetic acid formed in step (2) from the liquid mixture, there-by recovering the carbonylation catalyst remaining in the liquid mixture.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US68505776A | 1976-05-10 | 1976-05-10 | |
| US685,057 | 1976-05-10 | ||
| US75524576A | 1976-12-29 | 1976-12-29 | |
| US755,245 | 1976-12-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1081714A true CA1081714A (en) | 1980-07-15 |
Family
ID=27103482
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA276,229A Expired CA1081714A (en) | 1976-05-10 | 1977-04-15 | Process for the manufacture of styrene |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS52136133A (en) |
| AU (1) | AU506781B2 (en) |
| BR (1) | BR7703000A (en) |
| CA (1) | CA1081714A (en) |
| DE (1) | DE2719840A1 (en) |
| FR (1) | FR2351072A1 (en) |
| GB (1) | GB1583091A (en) |
| NL (1) | NL7705003A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53147039A (en) * | 1977-05-30 | 1978-12-21 | Ube Ind Ltd | Preparation of carboxylic acid ester of hydroxymethyl-substituted aromatic compound |
| JPS5519247A (en) * | 1978-07-28 | 1980-02-09 | Sumitomo Chem Co Ltd | Preparation of high-purity styrene by dehydration reaction of alpha-phenylethyl alcohol |
| JPS61293936A (en) * | 1985-06-21 | 1986-12-24 | Kureha Chem Ind Co Ltd | Liquid-phase dehydration of alcohol having aromatic side-chain at alpha-site |
| AU2003263197A1 (en) | 2002-08-06 | 2004-02-25 | Shell Internationale Research Maatschappij B.V. | Process |
| CN113274996A (en) * | 2021-05-13 | 2021-08-20 | 山东齐鲁华信高科有限公司 | Catalyst for preparing styrene by alpha-phenethyl alcohol gas phase dehydration |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB981987A (en) * | 1962-02-03 | 1965-02-03 | Bayer Ag | A process for the production of organic acetates |
| DE1235879B (en) * | 1964-03-17 | 1967-03-09 | Basf Ag | Process for the production of alcohols by catalytic hydrogenation of carboxylic acids |
| US3526674A (en) * | 1968-08-05 | 1970-09-01 | Halcon International Inc | Process for the dehydration of aralkanols |
| DE2107913C3 (en) * | 1971-02-19 | 1979-10-04 | Bayer Ag, 5090 Leverkusen | Process for the production of benzyl acetate |
-
1977
- 1977-04-14 GB GB1554477A patent/GB1583091A/en not_active Expired
- 1977-04-15 AU AU24320/77A patent/AU506781B2/en not_active Expired
- 1977-04-15 CA CA276,229A patent/CA1081714A/en not_active Expired
- 1977-05-04 DE DE19772719840 patent/DE2719840A1/en not_active Withdrawn
- 1977-05-06 NL NL7705003A patent/NL7705003A/en unknown
- 1977-05-09 BR BR7703000A patent/BR7703000A/en unknown
- 1977-05-09 FR FR7714114A patent/FR2351072A1/en active Granted
- 1977-05-09 JP JP5300377A patent/JPS52136133A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| DE2719840A1 (en) | 1977-11-24 |
| BR7703000A (en) | 1978-02-08 |
| AU506781B2 (en) | 1980-01-24 |
| FR2351072B1 (en) | 1983-10-14 |
| AU2432077A (en) | 1978-10-19 |
| FR2351072A1 (en) | 1977-12-09 |
| GB1583091A (en) | 1981-01-21 |
| NL7705003A (en) | 1977-11-14 |
| JPS52136133A (en) | 1977-11-14 |
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