DE1543140A1 - Process for the alkylation of hydrocarbons - Google Patents

Description

PATENTANWÄLTE 1 E / ο -ι / η

I θ4 J I 4 U

DR. DIETER THOMSEN - DIPL INQ. HARRO TIEDTKE

8000 Munich 25 »May 7, 1965 Case P / 509.20 rod

Telephone 0811/744158 Telegram address ί Thopatent

The Iummus Comp New York, N.Y. (U&A.) '

Process for the alkylation of hydrocarbons

The invention relates to an improved process for the alkylation of hydrocarbons, and more particularly to a process for the alkylation of aryl compounds with the formation of n-alkylaryl hydrocarbons, and also the sulfonic acids and salts thereof.

The method according to the invention relates in particular to the production of n-alkyl hydrocarbons, in particular n-Alkylbenzene hydrocarbons, which are then sulfonated to form n-alkylbenzenesulfonic acids; the the latter, when neutralized with an alkali, such as caustic soda, lead to known types of biodegradable wetting agents, surface active agents

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and detergents, namely sodium n-alkyl benzene sulfonates.

Previously, in the manufacture of sodium n-alkylarylsulfonates, an alkyl hydrocarbon fraction has been utilized which has been derived from a petroleum hydrogen distillate which has a boiling range within the kerosene range. This hydrocarbon fraction was chlorinated, and the resulting alkyl chloride was with benzene, toluene, xylene or the like. condensed in the presence of a Friedel-Crafts catalyst, for example anhydrous aluminum chloride. If such an alkyl fraction is chlorinated and the chlorides are condensed with benzene, the result is alkylaryl hydrocarbon compounds which have become known as "kerylbenzenes".

Subsequently, benzene and propylene tetramer are used as starting materials used for the production of dodecylbenzene; this is then processed further, whereby dodecyl sulfonate is formed. While it is known That the alkylbenzenesulfonates are useful detergents has only recently been observed that the above named materials are not degraded by sewage flora or microorganisms and therefore accumulate in the groundwater. This problem occurs particularly when the alkyl group is branched, as for example in the Sodium tetrapropylene benzene sulfonates. Accordingly, there is interest in the industry in the manufacture of straight chain Benzenesulfonates, directed by the formula

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CK ₃ CCR ₂ ) _n Cii; CH ₂ ) _n Cfl ₃

may be illustrated, where M is alkali metal (or a quaternary nitrogen cation), in particular Sodium and m and η are integers such that the following relationship holds:

6 m + η 14

It is known that the n-alkylbenzenesulfonates, which at The best biodegradable are those who are taking the Phenyl group located near the end of the alkyl chain (n / m 1) is located. However, such materials are poor detergents. An example is sodium 1-tridecylbene sulfonate almost completely insoluble in water, although it can be solubilized by making it soluble with other alkyl benzene sulfonates is mixed, which contain the Phenylgrxppe arranged along the alkyl chain. So they contain the most effective detergents placed the phenyl group near the middle of the alkyl chain (n / m 1). In the production of synthetic detergents on the hunt for a compromise accordingly, for an optimal product it has been suggested that no more than 25% of the alkali be the phenyl group have substituted on the 2-carbon atom, further substituted £ 50 on the 2- and 3-carbon atoms.

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Furthermore, with reference to the formula given above, a mixture of homologues with not only results different values of m and n, but also different values of m + η, the most desirable detergents. A suitable homolog distribution of n-alkylbenzenes, useful in making detergents is illustrated in Table I below.

Table I.

Typical homolog distribution for percent alkylbenzenes

m + η

7 2

8 10

9 ₍ 20

10 40

11 25 11 3

As indicated above, the isomers are with the aryl groups near the end of the chain (n / m 1) easily biodegradable, while the isomers with the aryl groups near the middle of the chain (n / n 1) lead to detergents which have the best washing effect. It can be seen that for each value πι + η there is an optimal distribution of n / m. In the past it has been found that under all known conditions n / m has been too small. In particular, the content of 1- and 2-aryl-n-alkanes is too high

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It is an object of the invention to provide a method for achieving an optimal distribution of n / m isomers in the case of n-alkylaryl hydrocarbons with any Distribution of m + n.

Another object of the invention is to provide a new process for the alkylation of an aryl compound, giving rise to a smaller concentration. of 1 and 2-aryl-n-alky! Compounds.

Yet another object of the invention is to provide a new process for the alkylation of an aryl compound, being an increase in the concentration of n-alkylary! hydrocarbon with substitution taking place near the middle of the chain and a substantial reduction of the branched chain alkylaryl compounds takes place.

Another object of the invention is to provide a new process for the preparation of n-alkylbenzenes, the sulfonates of which have excellent detergent properties and can be broken down by microorganisms.

Furthermore, another object of the invention is to increase the yield of such n-alkylbenzene isomers, useful as detergents by reducing the formation of 1- and 2-phenyl-n-alkyl isomers.

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One method of making long chain normal n-alkylaryl hydrocarbons is by the Friedel-Crafts reaction of ary! compounds, e.g. benzene with n-alkyl chlorides, as illustrated by the equation below:

01

CH ₃ (CH ₂ ) _a CH (CH ₂ ) _b CH ₃ + CgHg ^ CH ₃ (CH ₂ ) _ffl CH (CH ₂ J _n CH ₃

where a and b are integers such that a + b = m + n.

The n-alkyl chloride can be obtained by chlorinating an n-paraffin mixture with a desired molecular weight distribution. Although the isomer distribution a / b by Chlorination is determined more or less arbitrarily, it has been found that the isomer distribution of the alkylbenzenes (m / n) is not determined solely by the isomer distribution of the chloride (a / b). In fact is the isomer distribution the alkylbenzenes that under normal alkylation conditions are formed, compared to the isomer distribution of the alkyl chloride obviously insensitive, so that even if one starts from a single alkyl chloride, a mixture of isomers results from alkylbenzenes; this is similar to the isomer distribution obtained with a chlorinated n-paraffin receives. The isomer distribution of the n-alkylbenzenes, ■ how to obtain them by performing the alkylation of benzenes under normal alkylation conditions is shown by modification of the solvent, varying the concentration of the

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Alkyl chloride in relation to aromatic hydrocarbon or not achieved by varying the catalyst concentrations.

It has been found that the isomer distribution of n-alkylaryl hydrocarbons can advantageously be modified by carrying out an alkylation at a temperature of about -25 ° to ⁰ ° C., ie a greater central substitution of the phenyl groups on n-alkyl hydrocarbons occurs. It has been found that the isomer distribution of the n-alkylaryl hydrocarbon can be improved even further by increasing the reaction temperature of the mixture rapidly to a temperature of about 30 ° to about 10O ⁰ G after the η-alkyl hydrocarbon at temperatures of partially alkylated about -25 ° to 1O ⁰ C. To carry out the alkylation of the n-alkyl chlorides within such a low temperature range, it is necessary that the concentration ratio of aryl compounds, n-alkyl chlorides and paraffin is selected so that the mixture is liquid (ie not frozen above 50 <fo ). The catalyst can be aluminum chloride. A solvent can be used to aid in achieving the low temperatures required for liquid phase alkylation; required sini. Such solvents are, for example, n-kerosene, carbon disulfide, pentane and liquid sulfur dioxide, n-kerosene being partially effective when n-kerosene chlorides are the alkylating hydrocarbons. The preferred ary] compounds are taken from the

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Range of benzene, toluene and xylene selected.

It has been found that the reactivity of 1-chloroalkane during alkylation is substantially less than that of the other chloroalkanes at such low temperatures; accordingly, a large percentage of the 1-chloroalkane is fed to the subsequent sulfonation reaction. However, the Reaktionsgeniisches react by subsequent rapid heating to a temperature of about 30 ° 'to about 100 ⁰ C, preferably 60 ⁰ O, and maintaining the reaction mixture under at such temperature for 4 to 40 minutes 1-Chloroalkane in the reaction mixture with the benzene formation of phenyl-alkanes, where the phenyl groups in the chain direction aif center are distributed. in this Weioe are the resulting compounds in their effects as detergents those materials consider that would be generated when the 1-chloro would directly replaced by a phenyl group.

According to a preferred embodiment of the invention a mixture of η-paraffins is first chlorinated to form n-alkyl chlorides. The mixture of η-paraffins is derived from a petroleum distillate fraction that boils in the kerosene range, the n-paraffins having 9 to 16 carbon atoms Have per molecule, preferably 11-14. It is desirable that the mixture is only partially chlorinated, so that the formation of polychlorides is reduced to a minimum.

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The resulting n-alkyl chlorides mixed with unreacted η-paraffins are then passed into a reaction zone. An aryl hydrocarbon, for example benzene, is introduced into the reaction zone in an amount of about 2 to 25 moles of the aryl compound per mole of n-alkyl chlorides, preferably 5 to 20 moles. A Friedel-Crafts catalyst, for example aluminum chloride, is added to the Mixture added; the mixture is maintained at a temperature of about -25 ⁰ C to 10 ⁰ C, but above the temperature of the mixture form a solid at the $ 50. The reaction mixture is held for 5 to 60 minutes under such conditions, preferably in a single batch reaction for a time sufficient for the reaction rate to about 10 fi falling down of the initial reaction rate. In a continuous reaction vessel the Yerweilzeit is set so as to be converted 75 to 95 ° of the i n-alkyl chlorides, preferably 85 to 90 1o.

The reaction mixture is then heated .to a temperature of about 30 ° to about 100 ⁰ C, preferably from 6O ⁰ C, and held for 4 to 40 minutes at such a temperature. The temperature is preferably increased rapidly to a higher temperature range, so that the central substitution of the unreacted n-alkyl chlorides is thereby improved.

The products from the alkylation zone are then isolated, for example by distillation and in a known manner

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se sulfonated, for example by the fact that the distilled Bringing n-alkylbenzenes with oleum so that n-Alkylbenzenesulfonsäuren are formed, which then with a aqueous sodium hydroxide solution are neutralized, whereby sodium n-alkylbenzenesulfonate are formed, which more have centrally substituted n-alkanes and less branched-chain sulfonates than previously obtained.

example 1

As an example of the method according to the invention, normal paraffin having a composition as shown in Table II was chlorinated on a steam bath until it had increased in weight by about $ 2.5. The mixture contained 80 grams of alkyl chlorides and 220 grams of unreacted paraffins.

Table II

Composition of normal paraffin niches

^C 12 24 Ί » ° 12 45 i ° ° 12 31 i »

To the reaction mixture were added 150 grams of benzene chloride and 6 grams of aluminum chloride. The reaction mixture was maintained at a temperature of -17.5 ⁰ C for 240 minutes; thereafter the reaction mixture was rapidly raised to temperature

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heated from 6O ⁰ C and 25 minutes held "at this temperature then w ^ rde hydrolyzing the product distilled and analyzed. The analysis is reported as Experiment A in the following Table III Furthermore, in the following Table III as Experiment B. the analysis of a product is given which was obtained by carrying out the alkylation of a similar mixture of n-alkyl chlorides at a temperature of 65 ^° C. Experiment C gives the analysis of that product which is obtained when an alkylation alone at the low level Temperature is performed without post-heating treatment.

Table III Attempt B Attempt C Isomers Attempt a MoIf HoIf KoIf 27 23 2 0 20th 18th 18th 3 0 18th 16 16 A 0 17th 17th 19th 5 0 19 · 19th 23 6.7 0 branched 3 1 chained 1

Although it has been explained that alkylation of the aryl compounds is carried out in the presence of aluminum chloride, other catalysts are also contemplated. Accordingly, the Friedel-Crafts catalysts are generally metal halide catalysts from the Lewis-

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acid type, with corresponding metal halides for example Are aluminum halides, boron halides and iron halides.

Many modifications and variations are permissible within the scope of the invention.

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Claims (1)

1543H0 - 13 claims 1) A process for the alkylation of Ary! Compounds with an n-alkyl halide to increase the central substitution on the n-alkane, characterized in that (a) the aryl compound with the n-alkyl halide at a temperature between about -25 ⁰ C and 1O ⁰ C brings in the presence of a Friedel-Crafts catalyst to initiate alkylation of the aryl compound into contact and (b) after the temperature of the Reaktionsgemisc'nes to a value of about 30 ° increased to 100 ⁰ C. 2) Process according to claim 1, characterized in that for the formation of n-alkylaryl hydrocarbons (a) the n-alkyl halides having about 9 to 16 carbon atoms per molecule with an aryl compound at a temperature of about -25 C to 10 C in the presence of one Friedel-Crafts catalyst leads to initiation of alkylation into contact, (b) then heating the reaction mixture to a temperature of about 30 ° to about 100 ⁰ C and (c) n-Alkylarylkohlenwasserstof ~ fe obtained from the resulting reaction mixture. 3) Verfahrennach one of the preceding claims, characterized in that the reaction mixture takes 5 to 60 minutes is held at the lower temperature range for a long time. 4) Method according to one of the preceding claims, characterized characterized in that the reaction mixture at the low 909850 / Ί 54 1 1543U0 Geren temperature is maintained until the reaction rate is about 10 io of the original reaction rate. 5) Process according to one of the preceding claims, characterized in that the reaction mixture is kept at the lower temperature until 75 to 95 $> are converted from the n-alkyl halides. 6) Method according to one of the preceding claims, characterized in that the Ary! Compound is a compound from the series benzene, toluene and xylene is used. 7) "Method according to one of the preceding claims, characterized in that the reaction mixture at a temperature is held within the higher temperature range for 4 to 40 minutes. 8) Method according to one of the preceding claims, characterized in that within the lower temperature range less than 50 $ of the reaction mixture is present as a solid. 9) Method according to one of the preceding claims, characterized in that the reaction mixture is quickly brought to the temperature according to step (b). 10) Method according to one of the preceding claims, 90 90 50 / 15A1 _ 15 - characterized in that n-alkyl chlorides are used as n-alkyl halides with 11 to 14 carbon atoms can be used. 11) Method according to one of the preceding claims, characterized in that a molar ratio of aryl compound to η-alkyl halides of 1: 1 to 25: 1 is used. 12) Method according to claim 11, characterized in that a molar ratio of 5: 1 to 20: 1 is used. 13) Method according to one of the preceding claims, " characterized in that aluminum chloride is used as the Friedel-Crafts catalyst. 14) Method according to one of the preceding claims, characterized in that the alkylation is carried out in the presence of a solvent. 15) Method according to one of the preceding claims, characterized in that the solvent is sulfur dioxide is used.' 16) Method according to one of the preceding claims, characterized in that the formation of n-alkylaryl hydrocarbons as a detergent precursor (a) a mixture of η-paraffin with 9 to 16 carbon atoms per molecule under Formation of η-alkyl halides halogenated, (b) the n-alkyl halides with an aryl compound at a temperature of 909850 / T 54 1 ^{BAD 0R (G |} NAt ■ '. Ί543-Η0 -25 ⁰ C to 1O ⁰ C in the presence of a Friedel-Crafts catalyst. bringing into contact (c) thereafter heating the mixture to a temperature of about 30 ° to about 100 ⁰ C and (d) the n-Alkylary! hydrocarbon from the reaction mixture wins. .17) Method according to spoke 16, characterized in that η-paraffins with 11 to 14 carbon atoms are used. 18) Method according to one of the preceding claims, characterized in that the solvent used is non-chlorinated n-paraffin. 19) Method according to one of the preceding claims, characterized characterized in that the sulfur dioxide used as the solvent is liquid. 20) Method according to one of the preceding claims, characterized in that the mixture used of n-paraffins is derived from a petroleum fraction that boils in the kerosene range. 21) Method according to one of the preceding claims, characterized in that one for the formation of n-alkylbenzene · sulfonates with an increased concentration of centrally substituted sulfonates (a) a mixture of η-paraffins with 9 to 16 Carbon atoms per molecule with formation of n-alkyl chlorides chlorinated, (b) benzene and the n-alkyl chlorides in a molar ratio from 1: 1 to 25 .: 1 in the presence of aluminum ι 909850/1 5 A1 ■. . ■ '15 4 31Λ O Chloride mixes, (c) the temperature of the mixture for the partial alkylation of the benzene with the formation of n-alkylbenzenes • for 10 to 60 minutes at a value * of about -25 ⁰ C to about 10 ⁰ C, (d) then the · temperature increase of the mixture to a "value of 30 ° to 100 ⁰ C, (e) the Reaktionsgeraisch 4
for up to 40 minutes at a temperature range according to stage
(d) holds, (f) extracts the n-alkylbenzenes from the reaction mixture, (g) sulfonates the n-alkylbenzenes according to stage (f), (h) • * the η-alkyl benzenesulfonic acids according to stage (g). neutralized
and (i) n ^ -alkylbenzenesulfonate wins. ORIGINAL INSPECTED 850/1541