Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Organic compound containing
Reexamination Certificate
2001-05-17
2004-01-13
Bell, Mark L. (Department: 1755)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Organic compound containing
C502S162000, C502S168000
Reexamination Certificate
active
06677269
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a method for alkylating aliphatic or aromatic hydrocarbons with olefins using solid hydrogen fluoride-equivalent catalysts. The process is environmentally safe and represents improved and simplified technology easily adaptable to presently operating commercial hydrogen fluoride alkylation plants.
BACKGROUND OF THE INVENTION
Anhydrous hydrogen fluoride is widely used as a catalyst in the petrochemical industry. It is particularly effective as alkylation catalyst, such as in the production of high-octane gasoline via isoalkane-olefin alkylation. Similarly, detergent alkylates are produced by alkylating aromatic compounds, such as benzene. These technologies have achieved significant application in industry. At the same time, because of the volatility of hydrogen fluoride (HF; boiling point of about 19.6° C.), the environmental and health dangers posed by accidental release from industrial reactors or storage tanks is increasingly unacceptable. To solve this problem, industry has reverted either to the use of sulfuric acid, a less suitable but also less volatile alkylation catalyst, or has operated in a manner that decreases or minimizes the volatility of hydrogen fluoride.
For example, U.S. Pat. No. 5,073,674 discloses the utility of liquid onium polyhydrogen fluoride complexes, containing about 70% to 95% by weight of hydrogen fluoride, as alkylation catalysts. These liquid catalysts, which are not polymer-based, typically have a relatively low molecular weight, optionally contain an additional Lewis acid halide or strong Bronstead acid co-catalyst.
Certain polyhydrogen fluoride complexes, such as polyhydrogen fluoride complexes of pyridine and its derivatives, are liquids which are used as fluorinating agents. For example, anhydrous hydrogen fluoride in the presence of pyridine has been used for fluorinating steroids (R. R. Hirschmann et al.,
J. Am. Chem. Soc.,
1956, 78, 4956). The 30% pyridine-70% hydrogen fluoride system (PPHF) was found to be particularly useful for this reaction (C. G. Bergstrom et al.,
J. Org. Chem.,
1963, 28, 2633) and subsequently was developed (Olah et al.,
J. Org. Chem.,
1979, 44, 3872, and references cited therein) as a general fluorinating agent. The PPHF reagent and subsequently developed related reagents (T. Fukuhara et al.,
Nippon Kagaku Kaish.,
1985, p. 1951) are, however, only suitable as convenient fluorinating agents and are not catalysts for alkylation.
Solid poly-4-vinylpyridinium polyhydrogen fluoride has also previously been utilized for fluorination (Olah et al.,
Synthesis,
1993, p. 693). This solid fluorination agent, which contains only 35% to 60% hydrogen fluoride by weight is not effective as an alkylation catalyst. Acidic metal hydrogen fluorides, such as those of the type M
+
HF
2
−
, as well as most other salts of hydrogen fluoride, also fail to catalyze the alkylation of hydrocarbons.
SUMMARY OF THE INVENTION
This invention is based, in part, on the discovery that certain solid polymeric onium polyhydrogen fluoride complexes can be used to catalyze or facilitate the alkylation of aliphatic or aromatic hydrocarbons with olefins.
One embodiment of the invention relates to a method of alkylating an aliphatic or aromatic hydrocarbon with an olefin, which comprises contacting the aliphatic or aromatic hydrocarbon with the olefin in the presence of a solid polymeric onium polyhydrogen fluoride complex under conditions sufficient for the alkylation of the aliphatic or aromatic hydrocarbon.
Advantageously, polymeric onium polyhydrogen fluoride complexes used in the invention are solid. In a preferred embodiment, the polymeric onium polyhydrogen fluoride complex contains from about 70% to 95% by weight hydrogen fluoride. In another preferred embodiment, the polymeric onium polyhydrogen fluoride complex contains in some or all of its repeat units a nitrogen, phosphorus, or sulfur atom capable of forming an onium fluoride moiety upon reaction or complexation with hydrogen fluoride.
In another embodiment, the method may further comprise contacting the aliphatic or aromatic hydrocarbon and the olefin with a Lewis acid halide or a strong Bronstead acid. When added, the co-catalyst is preferably present in an amount from about 0.1% to 10% by weight of the polymeric onium polyhydrogen fluoride complex.
Another embodiment of the present invention relates to a process for forming a solid polymeric onium polyhydrogen fluoride complex, which comprises contacting a homopolymer or copolymer including, in at least one repeat unit, an atom, preferably nitrogen, phosphorus, or sulfur, capable of forming an onium fluoride moiety upon reaction or complexation with a source of hydrogen fluoride, preferably anhydrous hydrogen fluoride, under conditions sufficient to form the solid polymeric onium polyhydrogen fluoride complex.
Still another embodiment relates to a process for removing hydrogen fluoride from an alkylation product of the invention by contacting it with a solid homopolymer or copolymer including, in at least one repeat unit, an atom, preferably nitrogen, phosphorus, or sulfur, capable of forming an onium fluoride moiety upon reaction or complexation with a source of hydrogen fluoride, under conditions sufficient for the solid homopolymer or copolymer to complex hydrogen fluoride. In a preferred embodiment, the alkylation process does not necessitate any caustic or aqueous washing steps.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is based on the unexpected discovery that certain environmentally-friendly, solid polymeric onium polyhydrogen fluoride complexes can, in fact, catalyze the alkylation of aliphatic or aromatic hydrocarbons with olefins.
As used herein, the term “solid polymeric onium polyhydrogen fluoride complex” refers to any solid polymeric or oligomeric material containing in some or all of its repeat units an atom, preferably nitrogen, phosphorus, or sulfur, more preferably nitrogen, capable of forming an onium (e.g., preferably ammonium, phosphonium, or sulfonium) fluoride moiety with hydrogen fluoride. Suitable solid polymeric onium polyhydrogen fluoride complexes include, but are not limited to, complexes and/or reaction products of hydrogen fluoride and polymers such as, but not limited to, poly(vinylpyridine) and poly(aminomethyl styrene), as shown below:
as well as mixtures or copolymers containing same, wherein “n” denotes the number of repeat units. With appropriate amounts of anhydrous hydrogen fluoride, the polymers or oligomers can form corresponding stable poly(hydrogen fluoride) salts. Examples of the prepared solid polyhydrogen fluoride complexes include, but are not limited to, polyvinylpyridinium polyhydrogen fluoride (PVPHF) or poly(4-aminomethyl)styryl polyhydrogen fluoride (PAMSHF), as shown below:
as well as mixtures or copolymers containing same, wherein m is such that the resultant polymeric onium polyhydrogen fluoride complex can catalyze an alkylation reaction. The range of values for m for each polymeric onium polyhydrogen fluoride complex may depend on the repeat unit weight of the non-complexed polymers, and is preferably such that the solid polymeric onium polyhydrogen fluoride complex contains from about 70 to about 95 weight percent hydrogen fluoride, with the polymeric component being present in an amount from about 30 to about 5 weight percent. For example, m can be from about 5 to about 200, or from about 10 to about 100. The solid polymeric onium polyhydrogen fluoride complexes thus formed can serve as solid equivalents of anhydrous hydrogen fluoride, facilitating alkylation reactions at their surfaces and/or providing hydrogen fluoride in low concentrations to hydrocarbons with which they come in contact.
The use of solid polymeric onium polyhydrogen fluoride complexes to effect alkylation has other significant advantages. For example, their reduced volatility reduces accidental atmospheric release of gaseous hydrogen fluoride. The polymeric onium polyhydrogen fluoride complexes can also be efficie
Bell Mark L.
Pasterczyk J.
Pennie & Edmonds LLP
LandOfFree
Environmentally safe alkylation of aliphatic and aromatic... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Environmentally safe alkylation of aliphatic and aromatic..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Environmentally safe alkylation of aliphatic and aromatic... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3200081