US 5,763,721 A · Hydrodealkylation of C9+ aromatic compounds

Abstract

A catalyst composition and a process for hydrodealkylating a C.sub.9 + aromatic compound such as, for example, 1,2,4-trimethylbenzene to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises an alumina, a metal oxide, a phosphorus oxide and optionally, an acid site modifier selected from the group consisting of silicon oxides, sulfur oxides, boron oxides, magnesium oxides, tin oxides, titanium oxides, zirconium oxides, molybdenum oxides, germanium oxides, indium oxides, lanthanum oxides, cesium oxides, and combinations of any two or more thereof. The process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Claims33

Dependent claims

A process comprising contacting a fluid which comprises a C.sub.9 + aromatic compound with a catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon wherein said catalyst composition comprises a metal oxide-promoted alumina having incorporated therein a silicon oxide and a phosphorus oxide;

the metal of said metal oxide is selected from the group consisting of cobalt, molybdenum, nickel, rhodium, palladium, platinum, chromium, tungsten, and combinations of any two or more thereof;
the weight % of said metal oxide in said catalyst composition is in the range of from about 0.1 to about 60%;
and said catalyst composition is treated with steam for converting said metal to corresponding metal oxide before being contacted with said fluid.

A hydrodealkylation process comprising contacting, in the presence of a hydrogen-containing fluid, a fluid comprising a C.sub.9 + aromatic compound with a catalyst composition under a condition sufficient to effect the conversion of said C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon wherein said catalyst composition is prepared by the steps comprising:

(1) contacting an alumina with an acid site modifier precursor under a condition sufficient to incorporate said acid site modifier precursor into said alumina to form an acid site-modified alumina;
(2) contacting said acid site-modified alumina with a phosphorus-containing compound and a metal compound under a condition sufficient to incorporate said phosphorus-containing compound and metal compound into said acid site-modified alumina to produce a modified alumina;
and (3) treating said modified alumina with steam under a condition sufficient to effect the conversion of said metal compound to its corresponding metal oxide wherein said acid site modifier is selected from the group consisting of silicon-containing compounds, sulfur-containing compounds, boron-containing compounds, magnesium-containing compounds, tin-containing compounds, titanium-containing compounds, zirconium-containing compounds, molybdenum-containing compounds, germanium-containing compounds, indium-containing compounds, lanthanum-containing compounds, cesium-containing compounds, and combinations of any two or more thereof;
and the metal of said metal compound is selected from the group consisting of chromium, cobalt, molybdenum, nickel, rhodium, palladium, platinum, tungsten, and combinations of any two or more thereof.

1 more element

A process for converting a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon comprising contacting, in the presence of a hydrogen-containing fluid, a fluid comprising said C.sub.9 + aromatic compound with a catalyst composition under a condition sufficient to effect the conversion of said C.sub.9 + aromatic compound to said C.sub.6 to C.sub.8 aromatic hydrocarbon wherein said catalyst composition is prepared by the steps comprising:

(1) contacting an alumina with a phosphorus-containing compound, a silicon-containing compound, and a metal compound under a condition sufficient to incorporate said phosphorus-containing compound and metal compound into said alumina to produce a modified alumina;
and (2) treating said modified alumina with steam under a condition sufficient to effect the conversion of said metal compound to its corresponding metal oxide wherein
the metal of said metal compound is selected from the group consisting of chromium, cobalt, molybdenum, nickel, rhodium, palladium, platinum, tungsten, and combinations of any two or more thereof;
said silicon-containing compound is selected from the group consisting of poly(phenylmethylsiloxane), poly(phenylethylsiloxane), poly(phenylpropylsiloxane), hexamethyldisiloxane, decamethyltetrasiloxane, diphenyltetramethyldisiloxane, tetraethyl orthosilicate, tetrabutyl orthosilicate, tetrapropyl orthosilicate, trimethylchlorosilane, chloromethyldimethylchlorosilane, N-trimethylsilylimidazole, N,O-bis(trimethylsilyl)acetamide, N-methyl-N-trimethylsilyltrifluoroacetamide, t-butyldimethylsilylimidazole, N-trimethylsilylacetamide, methyltrimethoxysilane, vinyltriethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, (3,3,3-trifluoropropyl)trimethoxysilane, 3-(2-aminoethyl)aminopropyl!trimethoxysilane, cyanoethyltrimethoxysilane, aminopropyltriethoxysilane, phenyltrimethoxysilane, (3-chloropropyl)trimethoxysilane, (3-mercaptopropyl)trimethoxysilane, (3-glycidoxypropyl)trimethoxysilane, vinyltris(.beta.-methoxyethoxy)silane, (.gamma.-methacryloxypropyl)trimeth oxysilane, vinylbenzyl cationic silane, (4-aminopropyl)triethoxysilane, .gamma.-(.beta.-aminoethylamino)propyl!trimethoxysilane, (.gamma.-glycidoxypropyl)trimethoxysilane, .beta.-(3,4-epoxycyclohexyl)ethyl!trimethoxysilane, (.beta.-mercaptoethyl)trimethoxysilane, (.gamma.-chloropropyl)trimethoxysilane, and combinations of any two or more thereof;
and
said phosphorus-containing compound is selected from the group consisting of phosphorus pentoxide, phosphorus oxychloride, phosphoric acid, P(OR).sub.3, P(O)(OR).sub.3, P(O)(R)(R)(R), P(R)(R)(R), and combinations of any two or more thereof wherein R has one to about 10 carbon atoms and is independently selected from the group consisting of an alkyl radical, an alkenyl radical, an aryl radical, an aralkyl radical, an alkaryl radical, and combinations of any two or more thereof.

3 more elements

Dependencies are inferred from the claim text.

Hydrodealkylation of C9+ aromatic compounds

Life of this patent

Hydrodealkylation of C9+ aromatic compounds

Life of this patent

Abstract

Claims33