Aliphatic hydrocarbon alkylation process

Details Aliphatic hydrocarbon alkylation process Aliphatic hydrocarbon alkylation process

1999-08-23

2001-05-22

Johnson, Jerry D. (Department: 1764)

Chemistry of hydrocarbon compounds

Saturated compound synthesis

By condensation of a paraffin molecule with an olefin-acting...

C508S383000, C508S383000

Reexamination Certificate

active

06235959

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a process of using a catalytic composition, generally ionic and at least partially liquid, for the production of paraffinic hydrocarbons by addition of at least one olefin, preferably a low reactivity olefin such as ethylene, to at least one isoparaffin.
BACKGROUND OF THE INVENTION
A large number of acidic, liquid or solid catalysts are known for carrying out alkylation of isoparaffins such as isobutane and/or isopentane, using olefins such as propylene, 1-butenes and 2-butenes and isobutene. Industrially, the most frequently used catalysts are concentrated sulphuric acid and hydrofluoric acid, used alone or mixed with Lewis acids such as boron trifluoride. Using hydrofluoric acid in such processes is a problem because of its toxicity and high volatility. The use of sulphuric acid in such processes causes a problem due to high consumption of the catalyst necessitating expensive re-treatment. For this reason, the use of solid catalysts or catalysts which are supported on solids such as aluminosilicates or metal oxides such as zirconia treated with sulphuric acid has been recommended. However, solid catalysts have been proved to have low selectivity and low activity. Such catalysts are of particularly low activity with low reactivity olefins such as ethylene. Further, the catalysts usually used in industry react with ethylene to form stable esters. The use of aluminium chloride has been studied and proposed.
French patent application FR-A-2 626 572 and European patent application EP-A-0 576 323 have proposed the use of liquid ionic complexes which are formed by aluminium halides with certain quaternary ammonium halides or with certain amine hydrohalides, possibly with copper, to catalyse the paraffinic alkylation reaction. Such complexes, known as “molten salts”, have been described by C. H. Hussey in “
Advances in Molten Salts Chemistry
”, vol. 5, p. 185, Elsevier, N.Y., 1985, and by C. A. Angell and J. W. Shuppert in J. Phys. Chem. 84, 538, 1980. Such catalysts are particularly simple to use.
SUMMARY OF THE INVENTION
We have now discovered that the addition of at least one group IVB metal compound, in particular at least one group IVB metal halide, to one of the above salts, constituted by at least one aluminium halide and at least one quaternary ammonium halide and/or at least one amine hydrohalide, improves the reactivity of the catalyst and can enable the alkylation of low reactivity olefins with paraffins to be carried out with good conversions.
More precisely, the invention covered by the parent patent provides a catalytic composition comprising at least one aluminium halide, at least one quaternary ammonium halide and/or at least one amine hydrohalide and at least one group IVB metal compound. In the present case, the invention provides a process for alkylation of at least one isoparaffin by at least one olefin, in which the paraffins and olefins are brought into contact with the catalytic composition and the olefins are preferably selected from low reactivity olefins such as ethylene.
The aluminium halide for use in the present invention is preferably selected from the group formed by aluminium chloride and aluminium bromide.
The quaternary ammonium halide for use in the invention has already been described in French patent application FR-A-2 626 572, a description of which is repeated below. Thus the quaternary ammonium halide, which is acyclic or forms part of a cycle, has one of the following general formulae:
where R
1
, R
2
, R
3
, R
4
or R
5
, which may be identical or different, each represent hydrocarbyl residues generally containing 1 to 12 carbon atoms, for example alkyl, cycloalkyl, aryl, or aralkyl, R
5
also possibly being hydrogen or substituted hydrocarbyl residues containing at least one other atom such as nitrogen. Radicals such as R
6
may unite two of the above molecules to form, for example, R
1
R
2
N
+
═CR
3
—R
6
—CR
3
═N
+
R
1
R
2
(X
−
)
2
, R
6
possibly being an alkylene residue or a phenylene residue. Cyclic compounds III and IV are constituted by 4 to 10 atoms, preferably 5 to 6 atoms which, in addition to the nitrogen of the quaternary ammonium, may contain carbon atoms or optionally other nitrogen atoms, generally 1 or 2.
The following radicals constitute examples of groups R
1
, R
2
, R
3
, R
4
or R
5
: methyl, ethyl, propyl, isopropyl, butyl, secondary butyl, tertiary butyl, amyl, methylene, ethylidene, phenyl or benzyl; R
6
could be a methylene, ethylene, propylene or phenylene group.
In these formulae X represents a halide ion, preferably selected from the group formed by the bromide ion and the chloride ion.
The quaternary ammonium halide for use in the present invention is preferably selected from the group formed by imidazolium and pyridinium salts, preferred examples being N-butylpyridinium chloride, ethylpyridinium bromide, 3-butyl-1-methyl imidazolium chloride, diethylpyrazolium chloride and 3-ethyl-1-methyl imidazolium chloride.
The amine hydrohalides are preferably selected from the group formed by amine hydrochlorides and hydrobromides. More particularly, the amine hydrohalides are selected from the group formed by amine hydrohalides comprising one or two, preferably one, mole of hydrohalic acid, preferably hydrochloric or hydrobromic acid, per mole of amine. It is also possible to use at least one mixture of at least one amine hydrohalide containing one mole of hydrohalic acid per mole of amine and one containing two moles of hydrohalic acid per mole of amine. The hydrohalide derives from an amine or an acyclic diamine or an amine forming part of a cycle which contains at least one nitrogen atom and which generally has the folloing general formulae:
where R
1
, R
2
and R
3
, which may be identical or different, represent hydrocarbyl residues generally containing 1 to 12 carbon atoms, for example alkyl, cycloalkyl, aryl, or aralkyl. One of these substituents R
1
, R
2
or R
3
can be hydrogen. Cyclic compounds III and IV are generally constituted by 4 to 10 atoms, preferably 5 to 6 atoms, which, in addition to at least one nitrogen atom, can contain carbon atoms bonded by single or double bonds. Cyclic compounds III and IV can be condensed with other cycles and carry substituents such as amine functions, or fluorine, chlorine or bromine atoms.
The following radicals constitute examples of groups R
1
, R
2
and R
3
: methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, amyl, methylene, ethylidene, phenyl and benzyl. Cycles such as IV are generally represented by pyridines, imidazoles, triazines, pyrazoles, pyrimidines, and triazoles.
The amine hydrohalide for use in the invention is preferably selected from the group formed by hydrochlorides or hydrobromides of pyridine, 2-, 3- or 4-picolines, lutidines, 2-ethylpyridine, 3-isopropylpyridine, 2-chloro- or 4-chloro-pyridine, N,N-dimethyl-4-aminopyridine, N-methylimidazole, N-butylimidazole, piperidine and N-methylimidazoline.
The catalytic composition of the invention also comprises, and this constitutes one of the characteristics of the invention, at least one group IVB metal compound, i.e., selected from the group formed by titanium, zirconium and hafnium.
The group IVB metal compound for use in the invention is generally selected from the group formed by an acetate, sulphate, nitrate, perchlorate and the halides. The group IVB metal compound for use in the invention is preferably a halide, which avoids introducing supplemental ions into the reaction medium. More preferably still, the group IVB metal compound for use in the invention is selected from the group formed by zirconium tetrachloride, titanium tetrachloride, titanium trichloride, zirconium tetrabromide, titanium tetrabromide, hafnium tetrachloride and hafnium tetrabromide.
The components of the mixtures defined above are preferably used in a molar ratio of aluminium halide to quaternary ammonium halide and/or amine hydrohalide in the range 1.1:1 to 3.5:1, preferably in the range 1.5:1 to 3:1 and in a molar ratio of aluminium halide to

Affiliated with

Also associated with

Rating

Aliphatic hydrocarbon alkylation process does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Aliphatic hydrocarbon alkylation process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Aliphatic hydrocarbon alkylation process will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2550768