DD285090A5 - PROCESS FOR THE PRODUCTION OF LIGHT ALKYLATES - Google Patents

Abstract

The invention relates to a process for the production of light alkylates. The invention includes a process for the sulfuric acid catalyzed alkylation of alkenes with isobutane with the aim to increase the proportions of light alkylate, especially the Isopentane, at the expense of the 100C boiling alkylate components, especially the nonane fraction and higher boiling fractions, while reducing the consumption of acid. According to the invention, the target is achieved by doping the acid phase with a cationic surfactant in combination with electrolyte in the form of alkali metal or alkaline earth metal sulfate, hydrogen sulfate, phosphate or hydrogen phosphates, the tensioactive compounds such as fatty amines, preferably technical Rofamine, ammonium salts, sulfonium salts or phosphonium salts with a chain length of 12 to 18 carbon atoms or mixtures thereof in concentrations corresponding to 0.5 to 5 times the critical micelle concentration (CMC) and the electrolyte used in concentrations of 0.15 to 1.5 mol per kg of sulfuric acid is {alkylation. light alkylates; Schwefelsaeurekatalyse; surfactant additives; Elektrolytzusaetze}

Description

Characteristic of the known state of the art

It is known that, for the production of light alkylates from isobutane and olefins, preference is given to using butene / propene-type niches as olefin components (J. Weitkamp, S.Maixner, Erdöl, Kohle, Erdgas, Petrolchemie, 38 (11) (1983) 523).

It is also known that isopentane is formed in the HF-catalyzed Alkylierunysprozeß at the expense of the octane fraction when the acid phase relatively high concentrations of long-chain primary amines or quaternary ammonium salts are added (DD-WP 243923, DD-WP 243924).

Finally, it is known that when schv efelsäurekatalysierten alkylation dialkylmethylammonium salts, in combination with sodium sulfate, the proportions of the Cg fraction in the alkylate selectively increase, lead to yield increases and improve the octane number of the alkylate (SU Pat 988328).

Furthermore, various other additives (carboxylic acids, sulfonic acids, amines, alkylphenols) are known to provide positive effects in terms of octane level and reduction of acid consumption (U.S. Patent Nos. 3,555,515,3655,807, 3,865,896, 3,870,765, 3,888,735, 3,654,641, 4,004,100, 4,041,102,405,665) , 4467132, 4544794, 4541795, SU-Pat 825465, 988898, DOS 2422710, 2 541431; GM KRAMER, ACS Symposium Series (Ind. Lab. Alkyl.] 55 (1977) 1-261; Eur. Pat. Appl. 139,504).

It is disadvantageous that the use of propene in the sulfuric acid alkylation process results in an increased acidity and an octane number reduction of the alkylate (J. Weitkamp, S. Maixner, Erdöl, Kohle, Erdgas, Petrolchemie 36 (11) 11983] 523 and there cit. ).

A further disadvantage is that part of the o. G. Dopants due to poor solubility in the acid phase are discharged relatively quickly with the hydrocarbon phase (eg., Alkylcarbonsäuren, alkanesulfonic acids) and that others are economically unfavorable or only limited available (US Pat 3887 635) are degraded relatively quickly or too heavy lead to controllable emulsions.

(DOS 2422710, DOS 2541431, Jpn. Kokai 7664507, SU-Pat 988328).

Object of the invention

The aim of the invention is therefore an economical process for the production of light alkylates from olefins, in particular butenes, pentenes or mixtures thereof and isobutane, the o.g. Disadvantages not showing, but the advantage of a reduction de! Has acid consumption.

Presentation of the essence of the invention

The invention has for its object to provide a process for the preparation of alkylates with high levels of hochoktaniger components, especially under 100 ⁰ C boiling high-octane components that are important for the adjustment of the cold start behavior, the number of front octaves and the vapor pressure parameters of carburetor fuels. This object is achieved by the sulfuric acid phase combined additives of a tensioaktive compound such as technical fatty amines eg: Rofamin KD, Rofamin T, Rofamin TD, Rofamin 7 20, Rofamin RD, preferably Rofamin KD and Rofamin TD, technical trimethylammonium salts such as Quats I from the VEB hydrogenation plants Rodleben or primary, secondary or tertiary aliphatic amines or quaternary ammonium salts, sulfonium salts, phosphonium salts and mixtures thereof, in particular amine general formula R ¹ NH ₂ , R ¹ R ² NH, R'R ² R ³ N, wherein R ¹ = C ₆ Hi ₃ to C _n Hn, R ² = Hbzw. CH ₃ DJsC ₄ Hg ₁ R ³ = Hbzw. CH ₃ to C ₄ H ₉ , preferably R ¹ = C ₁₀ H ₂₁ to Ci ₈ H ₃₇ , R ² and R ³ = H or CH ₃ , and at the same time a

Electrolyte are added. Alkali or alkaline earth metal hydrogensulfate or alkali metal or alkaline earth metal sulfate, alkali metal or alkaline earth metal hydrogen phosphate or alkali metal or alkaline earth metal phosphate prove to be particularly suitable as the electrolyte additive. In this case, the Tensld the sulfuric acid phase is preferably added in concentrations corresponding to the 0.6 to Efachen critical Micellbiidungskonzentration (CMC) and the concentration of the electrolyte 0.15 to 1.5 mol per kg of sulfuric acid, preferably 0.6 mol. Among the usual for the sulfuric acid catalyzed alkylation of olefins, preferably butenes, pentenes or mixtures thereof, with isobutane customary process conditions (see J. Weitkamp, S.Maixner, petroleum, coal, natural gas, petroleum 36 (11) [1983] 623 and therezit Lit.), the proportion of isopentane increases mainly at the expense of the nonane fraction and the higher-boiling alkylate fractions, while the acid consumption is reduced by 30-50%.

With the invention, a control of the complex alkylation process with selectivity increase in favor of lighter alkylate components at the expense of heavy components (> C ₈ ) is achieved. Such alkylates are of increasing importance as blending components for unleaded premium gasoline.

exemplary The invention will be explained in more detail by way of examples.

The figure shows a laboratory apparatus. This consists of a KPG stirrer A with cannulated teflon discs with baffles B. The KPG stirrer A is guided via the Teflon guide C. For cooling the hydrocarbon feed mixture, a cooling jacket H is provided. The laboratory apparatus is additionally provided with an acid feed valve F and an alkylate exhaust G.

Under the usual alkylation process parameters (reactor temperature 0-5 ⁰ C, isobutane: butene ratio 10: 1, contact time 10min, acid: hydrocarbon ratio 21) was in a laboratory apparatus consisting of a vertically arranged, thermostatable reactor-settler Combination (see Fig.), Alkylated. The functioning as Settier upper part of the apparatus has to overflow a free space of about 50cm ³ ; the reactor contains 70 cc of 94-96% sulfuric acid. The precooled hydrocarbon feed mixture is introduced via the cochlea E by means of a metering pump via the glass frit D in the reactor bottom at a metering rate of 4 g / min, wherein the Kohlenwassertoff ascend in the acid phase finely distributed; Stirring speed> 1000rpm. The doping of the acidic phase was carried out externally. The feed mixture contained 2.34 kg of isobutane, 0.45 kg of η-butane and 0.23 kg of butenes per kg of n-hexane.

Example 1 (known method)

1.0 kg of the o.g. Feed mixture with the IsobutaniButen ratio 10: 1 were metered under the conditions given above and well emulsified by intensive stirring (> 10OOU / min). After phase separation in the settler, the hydrocarbon phase was taken off at the overflow and analyzed by capillary gas chromatography after neutralization and drying. The alkylate identified in the table corresponds to a distillation cut to 160 ° C; the inert components η-butane and η-hexane are excluded.

Example 2

1, Okg of the feed mixture were reacted and worked up analogously to Example 1, wherein previously the sulfuric acid phase with 0.688 · 10 ~ ^? kg (3CMC) of cetylamine and 0.008 kg of sodium bisulfate per kg of sulfuric acid was doped. The composition of the resulting alkylate is shown in the table.

Example 3 (inventive method)

1.0 kg of the starting mixture were reacted and worked up analogously to Example 1, the sulfuric acid phase having been previously doped with 0.668 × 10 ^-3 kg (3 CMC) of cetylamine and 0.065 kg of sodium hydrogensulfate per kg of sulfuric acid.

Example 4

1.0 kg of the starting mixture were reacted and worked up analogously to Example 1, the sulfuric acid phase having been previously doped with 0.587 × 10 ^-3 kg of Rofamin TD and 0.069 kg of sodium hydrogenphosphate per kg of sulfuric acid. The composition of the alkylate is shown in the table.

Dio shown illustration serves to illustrate the context of the invention and does not belong to the subject of Property right.

Table: Alkylate ordeno.g, feed mixtures having an ieobutane: butene ratio of 10: 1, H ₂ SO ₄ 96% (mass fractions in%)

fractions 1 8.47 2 8.20 example 3 4 8.71 8.18 17,02 15.06 ic ₆ 9.73 6.42 8.41 8.34 Σ0, 49.84 57.14 6.49 7.28 Σ0 ₇ 23.26 20,05 49.34 50.09 IC, 89.9 91.9 18.72 19.23 Z> C ₈ 88.5 90.3 91.8 91.6 RON 57.6 62.6 90.0 89.9 MOZ 42.4 37.4 61.8 62.1 % <160 ° C 38.2 37.9 % <160 ° C acid concentration 90.2 92.1 after 1 kg of coal 93.0 92.9 hydrogen throughput

Claims (1)

A process for the preparation of light alkylates by sulfuric acid-catalyzed alkylation of olefins, especially butenes, pentenes or mixtures thereof, with isobutane, characterized in that under the usual process conditions of Schwofeiaäurephase technical fatty amines such as Rofamin KD, Rofamin T, Rofamin TD, Rofamin T20, Rofamin RD , preferably Rofamin KD and Rofamin TD, technical trimethylammonium salts such as Quats I from the VEB Hydrierwerke Rodleben or primary, secondary or tertiary aliphatic amines or quaternary ammonium salts, sulfonium salts, phosphonium salts and mixtures thereof, in particular amines of the general formula R ¹ NH ₂ , R ¹ R ² NH, R ¹ R ² R ³ N, wherein R ¹ = C ₆ H ₁₃ to C ₂₀ H ₄ I, R ² = H or CH ₃ to C ₄ H ₉ , R ³ = H or CH ₃ to C ₄ Hg, preferably R ¹ = C ₁ OH ₂ I to C ₁₈ H ₃₇ , R ² and R ³ = H or CH ₃ , are added in concentrations of 0.5 to 5 times the critical micelle concentration (CMC) of the Amines or Am ingemisches in sulfuric acid, preferably 3 · CMC, and that at the same time an addition of electrolytes from 0.15 to 1.5 mol per kg of sulfuric acid, preferably 0.6 mol · alkali or alkaline earth metal hydrogen sulfate or alkali or alkaline earth metal sulfate, alkali or alkaline earth metal hydrogen phosphate or Alkaline or alkaline earth metal phosphate per kg sulfuric acid takes place. Field of application of the invention The invention relates to a process for the production of light alkylates from olefins, in particular butenes, pentenes or mixtures thereof and isobutane under sulfuric acid catalysis at known process conditions, wot oi the proportions of for the cold start behavior and the frontoktanzahl of carburetor fuels important low-boiling, high-octane isopentanes are increased so that its value increases as mixed components for carburettor fuels.