Method for preparing alkylate

Technical field:

The invention relates to a method for preparing alkylated oil, in particular to a kind of the ionic liquid/superacicd coupling catalytic isobutane/olefin reaction method for preparing alkylated oil.

Background technology:

Isobutane and butylene alkylation reaction is the preparation of alkylated oil to gasoline blending component of the highest, with high-octane, low-sulfur, non-aromatic, non-olefin, low Reid vapor pressure, and the like, with the oil refining industry of "liquid gold". In recent years, with the rapid development of the automobile industry, the increasingly strict fuel specification, high-octane oil rapid increase in demand, and MTBE the rise of the forbidden ethyl alcohol oil , will inevitably increase the dependence of the alkylated oil, promote all countries of the world the progress of the alkylation process.

My gasoline blending component mainly mainly to catalytic gasoline, about 75%, of the high performance serious shortage of the alkylated oil component only 2.7%, far lower than that in the developed countries oil content alkylation of (the United States, for example, alkylated oil accounts for gasoline 13-15%). Catalytic gasoline olefin and sulfur content is relatively high, especially sulfur content is as high as 756 PPM, difficult to meet new environmental protection laws strictly require (National standard IV clearly provides that olefin content of not more than 28%, sulfur content of not higher than 50 PPM). The reformate in the development of indicators by the benzene content in gasoline. Therefore in my vigorously develop the alkylation, the gasoline component in proportion to isoparaffin is to improve the most direct of my oil quality, of the most effective ways.

Because of the serious equipment problems such as corrosion and environmental pollution, traditional alkylation process (concentrated sulfuric acid process and hydrofluoric acid law) have been widely popularized of great restrictions. Alkylation of many have throwing device is in the state of the half-open semi-stop. For example, hydrogen fluoride hypertoxic is easy to form the leakage "aerosol" drifting, several kilometers square of the environment and human lives and great threat. Concentrated sulfuric acid while toxicity and volatility is low, however, an acid consumption is very large, approximately 1 ton of the alkylated oil can consume 100 kg of sulfuric acid. A great deal of waste acid generation and processing, not only to the very serious damage to the environment, is also greatly increases the production cost of the alkylated oil. Sulfuric acid regeneration (in addition to water and heavy hydrocarbons) is the cost of fresh sulfuric acid 2-3 times. Therefore development of a new generation of low pollution low acid consumption of obtained.wh alkylation catalyst has become a very important and urgent problems to be solved the subject of the study.

Around the world in recent years, various countries, including in the Academic and the industry a large amount of manpower, material, hydrofluoric acid and sulfuric acid with a view to resolving the problems in the process. The C4 alkylation reaction is mainly concentrated in the three research direction: advanced liquid acid alkylation technology, solid acid alkylation technology, traditional technological improvement of sulfuric acid and hydrofluoric acid. In recent decades in the solid acid catalyzed alkylation of a great deal of work has been done, but by far the deactivation is quick and regeneration high cost of the catalyst, this "bottleneck" problems have been technical breakthrough. The improvement of the traditional process, can only be modified to the prior art, could not solve the fundamental problem.

Ionic liquid entirely by the positive and negative ions is a kind of a liquid substance at room temperature, due to its unique physical and chemical nature of the: very low vapor pressure, broad liquid temperature range, good dissolving capacity, designability of the particular function, and so on, in the past two decades, an unprecedented in the field of chemical industry caused concern. An acidic ionic liquid catalytic alkylation preparation of alkylated oil has become advanced liquid acid catalysis in recent years the main development direction alkylation technology. Representative work is chlorine aluminum acid ionic liquid catalyst for C4 alkylation technology, Chinese Patent CN1432627A related patents, CN1836780A, such as CN101619010A. chlorine aluminum acid ionic liquid, however, because of its easy and containing electric power stronger compound complex, sensitive to water and oil of the product in question, such as overproof chlorinity, to a certain extent has limited its commercial application. Chinese Patent public number CN101177371A has offered a kind of the sulfonic acid ionic liquid catalyst for C4 alkylation method, the method has the mild reaction conditions, low-corrosion, is easy to be separated, can be recycled, and the like, but the existence of low catalytic activity, selectivity and TMP octane number is low, and the like of the oil.

In United States Patent US3778489 in, Parkert have referred to a wide variety of strong acid catalyst can be used as the catalytic olefin and isobutane alkylation reaction, including three halo methanesulfonic acid, trifluoromethane sulphonic acid, for example, and can be made by adding a proper amount of water, alcohol, thiol, ether to improve the catalytic activity of the material. In subsequently the United States Patent US4118433 in, triflic acid alone Innes referred to using the catalytic olefin alkylation its catalytic activity is poor, however, the mixing HF alkylation is greatly improved, and the yield of the quality of the oil and oil products. AppliedCatalysis   A the: General, VOl46 (1), 1996,107-117 in the literature, triflic acid is that Olah C4 alkylation of very fine catalyst, the addition of the trifluoroacetic acid or water can be adjusted and the acidity of a catalytic system for the catalytic activity.

Content of the invention

The purpose of this invention is to provide a with ionic liquid/superacicd coupling system is a catalyst, to isobutane and C4 olefin as raw materials for preparing alkylated oil.

The invention relates to method for preparing alkylated oil, with ionic liquid/superacicd coupling system as the catalyst, to isobutane and olefin as raw materials, the in -20 the [...] -80 within [...] , the reaction pressure is 0.1-1.6 MPa, than for the alkane is thin 1-200, the reaction time is 0.1-60 minutes.

In the above-mentioned method, the catalyst is an ionic liquid/superacicd coupling catalyst. In the coupling system which is characterized in that the cation can be a quaternary amine, imidazole, pyridine, containing sulfonic acid base class function cation, in the structure of cationic proton hydrogen such as one, two or more than two kinds of mixed composition, the anion can be a SbF₆^-, PF₆^-, BF₄, CF₃ SO₃^- one kind of structure, two or more than two kinds of mixed composition.

In the above-mentioned method, a plurality of super-coupling catalyst in halogenated hydrocarbon sulfonic acid, such as trihalogen methanesulfonic acid, five perfluoroethylene sulfonic acid, sulfonic acid, seven fluorine third , preferably trifluoromethyl sulfonic acid, in the whole catalyst in a proportion of 0.1-99.9%. Characterized in that after the liquid lies in adding ions, coupling the catalytic activity of the catalyst is, the solubility of the raw material for alkylation, product selectivity and the yield is greatly improved.

In the above-mentioned method, coupling catalyst in the ionic liquid, can be a neutral ionic liquid or an acidic ionic liquid. Characterized in that the cation can be quaternary amine, imidazole, pyridine, containing sulfonic acid base class function in the structure of cationic such as one or more than two, the anionic can be SbF₆^-, PF₆^-, BF₄^-, CF₃ SO₃^- in the structure of such as one or more than two. Wherein the ionic liquid is one-step acid-base neutralization, or season amine, the two-step synthesis ion exchange method.

In the above-mentioned method, the alkylation reaction is isobutane and C4 the reaction of olefins, wherein the C4 olefin is 1-butene, 2-butene, isobutene, two or more than two kinds of the above-mentioned butene mixture.

In this invention the raw materials of the alkylation reaction, olefin is 1-butene, 2-butene, isobutylene or the above-mentioned mixture, alkane is isobutane, the octane number of the product is the main component of C8 isoparaffinic. The reaction temperature can be -20 the the [...] -80 within [...] , preferably the 0-40 [...]. The reaction pressure can be controlled within 0.1-1.6 MPa, preferably 0.3-0.6 MPa. Isobutane and the proportion of olefins 1-200 range, preferably 5-15 between. The reaction time is 0.1-60 minutes, preferably 0.2-30 minutes. The reaction can be intermittent high pressure autoclave with stirring device or industrial use by the sulfuric acid alkylation reaction is carried out in the continuous production of the device.

Ion of the present invention liquid/superacicd coupling method for preparing alkylated oil, has the following advantages: 1) can improve the solubility of the isobutane in the catalyst, and the reactant contact of the catalyst, thereby reducing alkane alkene ratio , reducing the circulating quantity of isobutane, the energy consumption is reduced. 2) low volatility, low corrosivity, and easy separation of the product 3) to the water, air stable, overcomes the ionic liquid acrylic chlorine aluminum the shortcoming of the sensitive to water. 4) in the alkylate oil C8 selectivity is high, can be up to 80% or more; C8 oil of high octane number of the high selectivity of TMP, can be up to 7 above, basic industrial hydrofluoric acid and the level of the concentrated sulfuric acid alkylation process.