An improved method of obtaining a linear alpha - olefins (options)

 

(57) Abstract:

Usage: petrochemistry. The inventive ethylene will oligomerized to linear alpha-olefins using catalyst system containing a transition metal compound, organophosphorus sulphonate ligand and optionally the activator of the catalyst dissolved in the polar organic liquid selected from the group consisting of sulfolane, ethylene glycol, 1,4-butanediol and ethylene carbonate resulting and containing about 1-10 wt.% water. The technical result of the increase in the purity of alpha-olefins, lower distribution constants of the Schulz-Flory. 2 S. and 3 C.p. f-crystals, 6 PL.

Linear olefins are one of the most important classes of hydrocarbons used as raw materials in the petrochemical industry, and among them, linear alpha-olefin - non-branched olefins, whose double bond is located at the end of the chain, form an important subclass. Linear alpha-olefins can be converted into a linear primary alcohols by the reaction of hydroformylation (oxazines); alcohols with the number of carbon atoms less than eleven used in the synthesis of plasticizers, whereas those in which the number of carbon atoms more than eleven, use the s as the main products, which, in turn, can be oxidized for the production of synthetic fatty acids, especially with an odd number of carbon atoms used in the manufacture of lubricants. Linear alpha olefins are also used in the most important class of detergents for domestic use, namely linear alkylbenzenesulfonate, which is obtained by reaction of the Friedel-and benzene with linear olefins and subsequent sulfonation.

Another important field of application of the alpha-olefin is a radical of hydrobromide, which formed the primary bromaline, which is an important intermediate compounds in the production of thiols, amines, amine oxides and Quaternary ammonium compounds. The direct sulfonation of alpha-olefins formed sulfonates, alpha-olefin, a mixture of isomeric alkanesulphonic acids and Alisultanov that are effective cleaning agents even in hard water and at low concentrations. Linear alpha-olefins, especially those containing eight carbon atoms or less, also used as comonomers in the production of high density polyethylene and linear low density polyethylene.

Although linear olefins JW is popular olefins. Largely receiving alpha-olefins based on the oligomerization of ethylene, which is characterized by the fact that the resulting alpha-olefins have an even number of carbon atoms. Processes for the oligomerization of ethylene based mainly on the use as catalyst organoaluminium compounds or transition metals. When using catalytic amounts, for example, triethylaluminum, the oligomerization reaction of ethylene takes place at temperatures below 200oWith the formation of a mixture of alpha-olefins, whose number of carbon atoms obeys the distribution Schulz-Flory. In the range FROM6-C10branched alpha-olefins less than 4%, but the degree of branching increases to about 8% with increasing chain length up to 18. The modified process, the so-called ethyl method gives a high conversion of ethylene to alpha-olefin with a more controlled distribution, but the product quality is deteriorating, especially in the content of branched olefins. Thus, linear alpha olefins in the range FROM14-C16make up only about 76% of the product.

Significant progress in this area is associated with the use of transition metals as kataliticnijih catalysts allowed to obtain essentially 100% of monoolefins with more than 95% as alpha-olefins, less than 3% as of branched olefins, and less than 3% as intramolecular olefin. As catalysts insoluble in the hydrocarbon oligomerization in the presence of catalytic systems based on transition metals is usually carried out in a polar solvent to dissolve the catalyst. Ethylene and its oligomers have limited solubility in the used polar solvents. Accordingly, this type of oligomerization is associated with a 3-phase system: phase polar liquid solvent containing the catalyst, the second liquid hydrocarbon phase (consisting of the obtained oligomers), immiscible with the polar liquid phase and ethylene in the vapor phase. This system allows for continuous oligomerization, since ethylene can be entered in the polar phase and the products of oligomerization can be output as the hydrocarbon phase.

In the oligomerization of ethylene formed of alpha-olefins with the distribution of the Schulz-Flory, which depends on the catalyst and, at least for catalysts, representing in this case the greatest interest, to a lesser extent depends on the temperature. Class of catalysts containing component of the transition metal, i.e. a. See also U.S. patent 4 668 823. The use of such catalysts in the conditions when the distribution constant Schulz-Flory is in the range 0.55-0.65, gives the product of oligomerization, whose distribution of alpha-olefin in the range FROM6-C16particularly desirable from an economic point of view. Oligomerization in such conditions also provides about 10% of oligomers containing 20 or more carbon atoms (C20+), which are at ambient temperature waxy solid with limited solubility in the hydrocarbon phase of the oligomerization process described above, and which tend to separate in the form of waxy solids associated with this plugging of the reactor. The solution to this annoying problem described in the U.S. patent 5 523 508.

The formation of linear alpha-olefins by oligomerization of ethylene catalyzed by salts of transition metals such as Ni (11), characterized as the most important from a commercial point of view variable constant distribution Schulz-Flory, because it determines the distribution of the resulting oligomers. Because the required distribution of oligomer varies depending on the market, which implemented a whole the process of oligomerization. The distribution constant of the Schulz-Flory varies depending on the ligand, but to change the ligand to change the value of the approach is questionable, since only a limited number of ligands have commercial value because of its availability, cost and purity of the ligand. The distribution constant of the Schulz-Flory also changes somewhat with temperature, but this temperature dependence is usually insignificant. Thus, variables that can be used to regulate the quantities are very limited from the industrial point of view, and there is a need to introduce additional parameters to control the process of oligomerization.

In U.S. patent 4.711.969 discloses the use of Nickel reaction for the oligomerization of ethylene catalyzed by a catalytic system based on transition metal dissolved in a mixture of methanol and water, and the water content is 0.5-20%. However, the data presented in this patent show that the water reduces the catalytic activity. Therefore, there is a typical compromise between catalytic activity (or conversion) and selectivity.

Although oligomeric olefins, obrazuyetsa undesirable by-products are also formed significant amounts of branched olefins and internal olefins, which reduce the value of the product. Linear alpha olefins are used in the manufacture of detergents or direct sulfonation to the alkyl sulphonates, or by alkylation of an aromatic with subsequent sulfonation for the formation of linear alkylbenzenesulfonates. In any case, the linearity of the alkyl chain is a critical aspect of Biodegradability. When the oligomers are used, for example, to obtain polyethylene, the presence of intramolecular oligomers entails problems of reactivity relative to the formation of polyethylene; the presence of either branched or intramolecular olefin also leads to some differences in the properties of the resulting polyethylene differences, which are usually undesirable. Thus, minimization of the quantities of intramolecular and branched olefins formed by oligomerization of ethylene, characterized by the priority of any way.

Accordingly, it was quite surprising to find that, when the oligomerization of ethylene is carried out in the presence of transition metal compounds as catalyst in the environment sulfolane as the solvent, the presence of water affects this process in several Nepalis unexpected, because traditionally it is believed that the presence of water is negative and that you want to work with possibly more dry sulfolane. Observations also amazing and because of such effects has not been established. What was observed is that the water content in sulfolane solvent increases the purity of the olefin oligomers and leads to the formation of more alpha-olefins due to the reduced quantities of internal and branched olefins, which obviously is a very desirable result. It was also noted that the content of water affects the distribution of the Schulz-Flory, so that if necessary, the temperature increases offset , this offset can be balanced by increasing the concentration of water. Thus, the water content of the organic polar solvent acts as a means of controlling oligomerization of ethylene. Because the number and nature of the methods of process control are limited, it is an important discovery.

It was also found that increasing the concentration of water has a negative impact on the performance of the oligomer. However, in a system where the catalyst is a salt of the transition metal and socialnet balanced at least in part, by increasing the concentration of the catalyst or the concentration of the activator. Thus, the total effects from adding to the reaction system of water are favorable.

The aim of the present invention is to increase the purity of the ethylene oligomers in the process of oligomerization catalyzed by a catalytic systems based on transition metal dissolved in an organic polar solvent. The embodiment of the present invention includes adding water to the organic polar solvent in an amount of from 1 to 10 wt.% the solvent. In another embodiment of the present invention, the polar solvent contains from 2 to 5 wt.% water. In another embodiment of the present invention a catalytic system based on transition metal compound of the transition metal, phosphorus sulfate ligand and optional (but highly desirable) a catalyst activator. In another embodiment, the polar organic solvent is sulfolane.

The basis of the present invention is the finding that the addition of water to polar organic liquid serving as RA which has a receiving linear alpha-olefin oligomers with a higher degree of purity in comparison with those that are formed in the absence of water. It was also found that the water content of such polar organic solvent affects the distribution of the Schulz-Flory olefin oligomers formed in the oligomerization of ethylene. Thus, the water content in the polar organic liquid serving as a solvent, provides a means for regulating the distribution of olefinic oligomers. Although the performance of the process, i.e. the conversion rate of ethylene in oligomeric olefins in a single pass is reduced by adding water to polar organic solvent, this reduction is balanced by the increase in the concentration of the catalytic system and/or increase the concentration of the activator.

The method of the present invention relates to the oligomerization of ethylene catalyzed by a catalytic systems based on transition metals. Cm. for example, Ulman''s Encyclopedia of Industrial Chemistry, 5thEd., V. A13, pp. 245 et ff., VCH (1989). Especially desirable catalytic system based on transition metal is described in U.S. patent 4 689 437, which is included in the description by reference. It describes a catalytic system based on transition metal is a reaction product of three to the Anda. Other catalytic systems based on transition metals is described, for example, in U.S. patents 3 635 937; 3 637 636; 3 644 563; 3 644 564; 3 647 915; 3 661 803 and 3 686 159. Because catalytic systems based on transition metals for oligomerization of ethylene is well known, there is no need to consider them in detail in the description.

Typical concentrations of the catalyst are in the range from 10 to 1000 hours per million (ppm) by weight of the transition metal in the solvent. Some of the more active catalysts give high-speed response at a concentration of 40 hours per million (ppm), and a wider range of concentrations of the catalyst is from 0.1 to 1000 ppm (million hours). In a preferred embodiment of the present invention the concentration of catalyst range from 15 to 300 hours per million by weight. The authors of the present invention prefer to use the catalytic system described in U.S. patent 4 689 437, which is a reaction product of a transition metal compounds, catalyst and activator of organophosphorus ligand. Nickel is the preferred transition metal, and it was found that especially desirable activator is a borohydride, for example borohydride nutritech systems based on transition metals in General. Because they are described in the prior art, there is no need to consider them in detail in this specification.

Oligomerization of ethylene is a liquid-phase reaction, and the catalyst can either be dissolved in a solvent or suspended in a liquid medium. In an embodiment of particular interest, the catalyst is dissolved in a solvent, which is a polar organic liquid. The solvent should be inert to the components of the reaction and the equipment in the conditions of the process. Examples of suitable polar organic liquids as solvents intended for purposes of illustration, but not limitation, include sulfolane (tetramethylsilane), ethylene glycol, 1,4-butanediol and ethylene carbonate resulting in, as well as mixtures of the aforementioned compounds. In the considered in the description of the embodiment, the solvents that provide rapid phase separation from oligomeric products are preferred from the viewpoint of obtaining the phase of the polar solvent and hydrocarbon phases. The most preferred polar organic liquid as a solvent for the oligomerization of ethylene is sulfolan, in which the catalysts of the infusion is a temperature in the range from 5 to 200oWith the preferred range from 20 to 140oAnd the most preferred range of from 40 to 100oC. the Process can be performed at pressures in the range of 101.3 kPa to 34.6 MPa (from atmospheric pressure to about 5000 psig (350 kg/cm2), although the preferred pressures are in the range from 2.86 to 13.89 MPa (400-2000 psig (28-140 kg/cm2)). These pressures represent the pressure at which the ethylene is fed into the reactor and in which the supported reactor. When the ethylene will oligomerized using the catalyst of the present invention in the temperature range 40-100oWith optimal concentration of water in the polar organic solvent is in the range from 1 to 6 wt.%.

As a result of oligomerization are formed oligomers, which are the prevailing linear alpha-olefins, containing from four to more than 20 carbon atoms and having a low solubility in used polar solvents, especially if the solvent for catalytic systems based on transition metals of the present invention is sulfolan. Therefore, the formation of the oligomer is accompanied by the formation of separate hydrocarbon is engaged in the distribution of the Schulz-Flory. The application of the prior art, the present invention includes maintaining the concentration of water in the polar liquid organic solvent may be a low level, preferably at the level of around million shares (RRT), but certainly not more than a few tenths of a percent of water. The present invention is just the opposite in fact known technical solutions, and in fact is used as a solvent of a polar organic liquid, containing from 1 up to 10 wt.% water, more preferably from 2 up to 5 wt.% water, and most preferably 3 to 4 wt.% water. It was found that sulfolane containing this amount of water is particularly desirable and the preferred option. When the oligomerization of ethylene proceeds with the use of the catalysts of the present invention in the temperature range 40-100oWith the optimum water content is in the range from 1 up to 6 wt.%.

Example 1

The influence of water purity linear alpha-olefin.

System reactor continuous action consists of an autoclave with a stirrer, containing a solution of sulfolane and catalyst, and separator. The ethylene fed into the reactor with a speed of 160 g/h at dakoda from the reactor on the second line to the separator; sultanovici solution of catalyst recycle to the reactor, and the mixture product/ethylene output.

The catalyst solution is prepared by adding 1 mol. including sodium salt of 2-diphenylphosphino-1-naphtalenesulfonic acid and 2 hours of tetrafluoroborate Nickel in sulfolane at a total concentration of Nickel 25 hours per million (ppm) Ni. Then add a solution of the activator NaBH4with a ratio of 1 CH borohydride to 4 h of Nickel. Additional ligand,Nickel salt and an activator is added in a dry sulfolane in a molar ratio of 2:4:1 to ensure a degree of conversion of ethylene in the range of 10-50 wt.%. The reaction is carried out at a temperature of 60oC.

Carry out a similar reaction, except that the catalyst solution is prepared by adding 2 hours of tetrafluoroborate Nickel to a solution of 1 wt. % water sulfonate and 1 mol. including sodium salt of 2-diphenylphosphino-1-naphtalenesulfonic acid activator solution containing 1 h NaBH4in a dry sulfolane at a total concentration of Nickel approximately 15 PPT. The ligand of the Nickel salt and the activator is added at a molar ratio of 1:2:1 in sulfolane containing 1 wt.% water, to ensure a degree of conversion of ethylene in the range of 10-50 wt.%.

The degree of purity of LineIn> olefinic fraction. In the absence of water detinova fraction contained 95.05 wt.% the mission-1; in the presence of about 1.0 wt.% water sulfolane detinova fraction contained 95.99 wt.% the mission - 1. The main impurities are presented in table 1.

These results clearly indicate the beneficial effects of water on the purity of the olefin. This is confirmed by the following data, obtained using the same catalytic system with 3.5 wt.% water. System reactor continuous action consisted of an autoclave with a stirrer, containing a solution of sulfolane, and catalyst, and separator. Ethylene was supplied in the reactor with the speed of 405 g/h and the pressure 10,44 MPa (1500 psig). The temperature of the reactor was maintained at about 93oC. the Mixture of the solution of sulfolane, oligomeric product and unreacted ethylene was received from the reactor on the second line in the heated separator; sultanovici solution of the catalyst was recycled to the reactor, and the mixture product/ethylene out of the system. Target linear alpha-olefin and ethylene was further divided, and unreacted ethylene is recycled to the reactor.

The catalyst solution was prepared by adding 2 hours tosilata Nickel and 1 mol. including sodium salt of 2-butylphenylphosphine, contains 3 hours NaBH4when the total concentration of Nickel about parts 25. Additional ligand, Nickel salt and an activator was added in a molar ratio of 1: 2: 3 sulfolane containing 3.5 wt.% water, to achieve the degree of conversion of ethylene in the range of 10-50 wt.%. The results obtained are presented in table 2.

Thus, when using water in the amount of 3.5 wt. % there is an even greater positive effect.

Clearly demonstrating a beneficial effect of added water on the degree of purity of the alpha-olefin was carried out series of experiments to assess the effect of different concentrations of water on the conversion of ethylene, the maximum conversion rate and a constant distribution of the Schulz-Flory.

Examples 2-5

The effect of different concentrations of water

The same pilot plant described in example 1 (without adding water), worked with 95oC. Ethylene was applied to the reactor with a speed of 160 g/h at a pressure 10.44 MPa (1500 psig). The catalyst solution was prepared by adding 2 hours tosilata Nickel and 1 mol. including sodium salt of 2-butylphenylphosphine-4-methylbenzenesulfonic acid to the solution in sulfolane with an activator solution containing 3 h NaBH4, with the added different amounts of water in the range of 0.7 to 5 wt. %. The components of the catalyst was mixed for approximately one hour. The reaction was carried out without further addition of catalyst to until the reaction rate was reduced to an insignificant level. After complete addition of the catalyst was measured by the change in the rate of conversion of ethylene in time. The value of purity and alpha product is also measured as a function of time. Performance was calculated by comparing the total amount formed during the experiment, the target linear alpha-olefin to the total number entered at the beginning of the experience of the ligand.

The above data suggest that water generally reduces the degree of conversion of ethylene. A similar conclusion can be drawn when comparing the degree of conversion of ethylene at a constant reaction time, in this case, 4 h, as shown in table 4.

You should pay attention that there is detected a slight additional negative effect of water on the conversion of ethylene above about 2 wt.%.

Table 5 presents data on the performance (as defined above) at various concentrations in water.

Here again a slight on the 6 shows the effect of increasing concentrations of water on the distribution of the Schulz-Flory.

In contrast to the influence of water on the maximum conversion of ethylene and performance it turns out that the distribution constant Schulz-Flory reduced throughout the range of concentrations used water.

1. An improved method for the oligomerization of ethylene for the formation of linear alpha-olefins catalyzed by a catalytic system based on transition metal dissolved in the polar organic liquid containing water, wherein the use of a catalytic system containing a transition metal compound, organophosphorus sulphonate ligand and optionally the activator of the catalyst, use of the polar organic liquid is selected from the group consisting of sulfolane, ethylene glycol, 1,4-butanediol and ethylene carbonate resulting, with the specified polar liquid contains about 1-10 wt. % of water.

2. An improved method according to p. 1, characterized in that the polar organic liquid contains 2-5 wt. % of water.

3. An improved method according to p. 2, characterized in that the polar organic liquid contains about 3-4 wt. % of water.

4. An improved method according to any of paragraphs. 1-3, characterized in the Jena for the formation of linear alpha-olefins using the catalyst systems based on transition metal, includes stage

(a) introducing ethylene at a temperature oligomerization 40-100oWith the polar phase consisting essentially of a solution of catalyst systems based on transition metal in a polar organic liquid phase containing water;

(b) oligomerization of ethylene in the specified aqueous polar liquid phase with the formation of oligomers consisting essentially of linear alpha-olefins, separating these oligomers, forming a hydrocarbon phase, and

C) continuous removal of the specified hydrocarbon phase, wherein the use of a catalytic system containing a transition metal compound, organophosphorus sulphonate ligand and optionally the activator of the catalyst, use of the polar organic liquid is selected from the group consisting of sulfolane, ethylene glycol, 1,4-butanediol and ethylene carbonate resulting, with the specified polar liquid contains about 1-10 wt. % of water.

 

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FIELD: regeneration of heat and extraction of impurities.

SUBSTANCE: the invention is pertaining to the method of regeneration of heat and extraction of impurities from the area of the heat-producing reaction in the fluidized flow, conducted for conversion into light olefins of oxygenates present in the flow of the oxygenate (oxygen-containing) raw. raw. The offered method includes the new system of a two-stage quick chilling intended for extraction at the first stage of water from the outgoing from the reactor flow and regeneration of heat of this flow for the purpose, at least, of the partial evaporation of the raw flow due to indirect heat-exchange between the oxygenated raw and the flow of the upper product of the first stage or the flow of recirculation of the first stage. The flow of purification being withdrawn from the first stage, contains the large share of impurities and the high-boiling oxygenates. In the second stage besides conduct extraction of water from the products flow containing light olefins, and produce the flow of the purified water, which requires only the minimum evaporation of the water for production of the water flow of the high degree purification. The method allows to concentrate the impurities in a rather small flow and ensures the significant saving of power and money resources at production of a flow of the vaporous raw guided into the area of realization of the heat-exchange reaction in the fluidized flow.

EFFECT: the invention ensures concentration of the impurities in a rather small flow and the significant saving of power and money at production of the flow of the vaporous raw directed into the area of realization of the heat-exchange reaction in the fluidized flow.

19 cl, 3 tbl, 4 dwg, 5 ex

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