JP2006076895A - Method for producing internal olefin, internal olefin mixture and oil-drilling base oil containing internal olefin mixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an internal olefin in which α-olefin which is a raw material is stably isomerized while suppressing adverse reaction such as skeletal isomerization reaction or heavy reaction of the α-olefin by using an inexpensive catalyst. <P>SOLUTION: In the method for producing the internal olefin by isomerizing a 16-18C α-olefin in the presence of a zeolite and/or montmorillonite catalyst, dried air or nitrogen having ≤-50°C dew point is previously made to flow at ≥150°C and water attached to the catalyst is removed until dew point of outlet gas of a catalyst layer becomes ≤-40°C and the 16-18C α-olefin is isomerized at 70-175°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing an internal olefin in which an α-olefin having 16 to 18 carbon atoms is isomerized in the presence of a zeolite and / or a montmorillonite catalyst, an internal olefin mixture obtained by the method, and a petroleum containing the internal olefin mixture. More specifically, after drilling base oil, dry air or nitrogen having a dew point of −50 ° C. or less is circulated through the catalyst layer in advance to remove moisture adhering to the catalyst until the dew point of the catalyst outlet gas is −40 ° C. or less. , Internal isomerization of α-olefin, catalyst degradation and skeletal isomerization reaction, side reaction such as heavy reaction is suppressed, an efficient method for producing internal olefin, internal olefin mixture obtained by the method, and It relates to an oil drilling base oil containing an internal olefin mixture.

Conventionally, internal olefins are used in various applications, specifically, oil drilling base oils, detergent raw materials, paper sizing agent raw materials, lubricating oil base oils or raw materials, chemical raw materials, and the like.
And when an internal olefin is used for these uses, what is shown below is requested | required with respect to this internal olefin.
For example, in oil drilling base oil applications, internal olefins having 16 or 18 carbon atoms are generally used, but it is required to adjust the pour point, kinematic viscosity, etc. and to have high biodegradability.

As a method for producing such an internal olefin, a technique for internally isomerizing an α-olefin using a catalyst in which Pt, Ru, Ni or the like is supported on a support such as alumina or zeolite, or ferrilite which is a kind of zeolite is known. And has already been implemented industrially.
In general, skeleton isomerization reaction of internal olefins produces tri- or tetra-substituted olefins, which show changes in physical properties such as pour point lower than the original olefins, and biodegradation in the natural environment It is known that the sex decreases.
The use of internal olefins is diverse as described above, and pour point depression is preferred especially when used as an oil drilling base oil. However, due to recent environmental policies, raw materials with low biodegradability are used as detergents and oil drilling base oils. It is becoming virtually unusable for applications that are likely to be released into the natural environment.
Accordingly, there is a need for a catalyst and reaction conditions that can suppress the skeletal isomerization reaction and selectively perform only the internal isomerization reaction.
As a method for suppressing the skeletal isomerization reaction in the internal isomerization reaction of α-olefin using a zeolite catalyst, a method using a pentasil zeolite catalyst containing 1 to 10% by weight of nickel monooxide as a promoter (for example, Patent Document 1) And a method using an aluminophosphate-containing molecular sieve having a one-dimensional pore having a diameter of 3.8 to 5.0 mm as a catalyst is disclosed (for example, see Patent Document 2).
However, in these methods, the isomerization reaction temperature is 180 to 200 ° C. or higher in most cases, and the isomerization conversion rate is slightly low, and the reaction temperature is high. Along with this, there is a problem that the skeletal isomerization reaction and the heavy reaction cannot be ignored when the reaction temperature is raised.
Therefore, a method for producing an internal olefin that stably isomerizes an α-olefin while suppressing a skeletal isomerization reaction or a heavy reaction is desired.

US Pat. No. 6,054,629 US Pat. No. 6,281,404

  Under such circumstances, the present invention provides an internal structure that stably isomerizes an α-olefin while suppressing side reactions such as skeletal isomerization reaction and heavy reaction in the presence of an inexpensive zeolite and / or montmorillonite catalyst. It aims at providing the manufacturing method of an olefin.

As a result of intensive studies to achieve the above object, the present inventors have previously circulated dry air or nitrogen having a dew point of −50 ° C. or less to the catalyst layer at a predetermined temperature, and the dew point of the catalyst outlet gas is reduced. After removing the water adhering to the catalyst until -40 ° C or lower, by isomerizing the α-olefin, catalyst degradation, skeletal isomerization reaction (branched olefin formation reaction, etc.), heavy reaction (α-olefin) It was found that side reactions such as the dimerization reaction, etc.) were suppressed, and the α-olefin could be stably internal isomerized.
The present invention has been completed based on such findings.
That is, the present invention
1. In the method for producing an internal olefin by isomerizing an α-olefin having 16 to 18 carbon atoms in the presence of a zeolite and / or a montmorillonite catalyst, dry air or nitrogen having a dew point of −50 ° C. or less in advance is added to the catalyst layer. Circulate at a temperature of ℃ or higher, remove the water adhering to the catalyst until the dew point of the catalyst layer outlet gas is -40 ℃ or less, and then isomerize the α-olefin having 16 to 18 carbon atoms at a temperature of 70 to 175 ℃ And a method for producing internal olefins,
2. 2. The internal olefin according to 1 above, wherein the conversion rate of α-olefin is 90% or more, the production rate of the heavy reaction product is 3% by mass or less, and the production rate of the skeletal isomerization product is 2% by mass or less. Manufacturing method,
3. The method for producing an internal olefin according to the above 1 or 2, wherein the zeolite catalyst is MFI type zeolite,
4). The method for producing an internal olefin according to any one of 1 to 3 above, wherein the content of the α-olefin having 18 carbon atoms in the α-olefin is 20 to 35% by mass,
5. An internal olefin mixture having 16 to 18 carbon atoms obtained by the method according to any one of 1 to 4 above,
6). The oil drilling base oil comprising the internal olefin mixture having 16 to 18 carbon atoms as described in 5 above is provided.

  According to the method of the present invention, dry air or nitrogen having a dew point of −50 ° C. or lower in advance is passed through the catalyst layer at a temperature of 150 ° C. or higher, and the zeolite is exhausted until the dew point of the catalyst layer outlet gas becomes −40 ° C. or lower. And / or after removing water adhering to the montmorillonite catalyst, by internal isomerization of the α-olefin having 16 to 18 carbon atoms at 70 to 175 ° C., secondary reactions such as catalyst deterioration, skeletal isomerization reaction, and heavy reaction are performed. The reaction is suppressed, and the internal olefin can be efficiently and industrially advantageously produced stably.

The raw material α-olefin of the present invention is an α-olefin having 16 to 18 carbon atoms.
The ratio (mass ratio) of the α-olefin having 16 carbon atoms and the α-olefin having 18 carbon atoms in the raw α-olefin is not particularly limited, but is usually 20:80 to 35:65, preferably 25:75. ~ 32: 68.
The α-olefin having 16 to 18 carbon atoms is preferably obtained by distilling a low polymer obtained by low polymerization of ethylene using a Ziegler type catalyst.
This low polymer is a mixture of 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-icocene and the like.
Furthermore, the α-olefin used in the present invention can also be obtained by distilling an α-olefin obtained from a catalytic cracker or the like.

Examples of the catalyst used in the present invention include zeolite and montmorillonite catalyst.
Examples of the zeolite catalyst include natural zeolite and synthetic zeolite.
Examples of natural zeolite include chabasite, mordenite, erionite, faujasite, and clinobutyronite.
Examples of the synthetic zeolite include A type, B type, X type, Y type, L type, omega type, and MFI type.
Among these, the MFI type is preferable, and ZSM-5 or the like is preferable as the MFI type.
In the present invention, these zeolite catalysts may be used as they are, or those having acid properties controlled by acid treatment, ammonium ion treatment, ion exchange treatment, etc. may be used as necessary.
In particular, a proton type zeolite in which a part or all of the cation is substituted is preferable, and among them, H-ZSM-5 substituted with a proton is preferable.

Examples of the montmorillonite-based catalyst include minerals such as montmorillonite, nontronite, beidellite, heractite and saponite, which are classified as smectite minerals. Among these, montmorillonite is preferably used in terms of catalytic activity.
In the present invention, these montmorillonite-based catalysts may be used as they are, or those subjected to acid treatment, halogenation treatment, cation exchange treatment, and the like as required to control acid properties may be used.

Here, as the acid treatment, for example, the montmorillonite-based catalyst is dispersed in an aqueous solution containing an inorganic acid such as hydrochloric acid, sulfuric acid, phosphoric acid or the like, or an organic solvent liquid such as alcohol. It is possible to use a method of filtering, drying, and further performing a firing treatment if necessary.
In addition, as the halogenation treatment, for example, the montmorillonite-based catalyst is dispersed in an aqueous solution containing a halogen compound such as ammonium fluoride, aluminum fluoride, and aluminum chloride, heated as necessary, and then filtered. For example, a method of drying and further firing as necessary, or a method of filling the reaction tube with the montmorillonite-based catalyst and circulating the fluorohydrocarbon at a temperature of about 500 ° C. can be used.
On the other hand, as the cation exchange treatment, for example, a method of dispersing the montmorillonite-based catalyst in an aqueous solution containing various metal salts, exchanging the cation, filtering, and washing with water can be used.

In the present invention, before carrying out the isomerization reaction, the layer of the zeolite and / or montmorillonite catalyst prepared in this way is previously heated to a temperature of 150 ° C. or higher, preferably 180 ° C. or higher, more preferably 180 to A pre-treatment is performed until 300 ° C and dry air or nitrogen having a dew point of -50 ° C or lower, preferably -60 ° C or lower, and the dew point of the catalyst layer outlet gas is -40 ° C or lower, preferably -50 ° C or lower. Then, the water adhering to the catalyst is removed.
If the removal temperature of water adhering to the catalyst is less than 150 ° C., the activity of the catalyst is reduced, and in order to achieve a predetermined conversion rate, it is necessary to set the reaction temperature high, so that by-products such as oligomers ( α-olefin dimerization reaction product and the like).
Also, when the dew point of air or nitrogen used exceeds -50 ° C., the activity of the catalyst is reduced, and in order to achieve a predetermined conversion rate, it is necessary to set the reaction temperature high, so that by-products such as oligomers ( α-olefin dimerization reaction product and the like).
Furthermore, if the dew point of the gas after pretreatment exceeds −40 ° C., the catalyst life is shortened.

In the present invention, an α-olefin having 16 to 18 carbon atoms is brought into contact with the catalyst from which the adhering moisture has been removed as described above at a temperature of 70 to 175 ° C. to produce an internal olefin. .
In this internal isomerization reaction, α-olefin conversion is generally low at low temperatures, but skeletal isomerization reaction and the like are unlikely to occur, and the product contains an olefin whose double bond position has moved to the β-position or γ-position. Become the subject.
On the other hand, at high temperatures, the conversion rate generally increases with side reactions such as skeletal isomerization reaction and heavy reaction, and the selectivity decreases, and the double bond is transferred to the δ position or the inside thereof. Generation is promoted.
Therefore, in consideration of catalyst life, suppression of skeletal isomerization, and heavy reaction, the reaction temperature is usually selected in the range of 70 to 175 ° C, preferably 100 to 170 ° C in the present invention.
There is no restriction | limiting in particular about the reaction form, Any of a fixed bed flow type and a batch type (a continuous stirring tank is included) may be sufficient.
Since the reaction is not accompanied by a change in molecular weight, the reaction proceeds without problems even at normal pressure, and can be carried out usually at normal pressure to about 5 MPa, preferably at normal pressure to 1 MPa.

If the reaction mode is a fixed bed flow, alpha-olefin conversion and considering the productivity, etc., LHSV (liquid hourly space velocity) is generally about 0.1 to 10 ^-1, preferably 1～4H ^-1 Selected by range.
Moreover, when the reaction format is a batch type, the amount of zeolite and / or montmorillonite-based catalyst used is usually 1 to 60 parts by mass, preferably 10 to 50 parts by mass, with respect to 100 parts by mass of the raw α-olefin. Preferably it is chosen in the range of 20-40 mass parts.
In this case, the reaction time depends on the reaction temperature, the desired α-olefin conversion rate, etc., and cannot be determined in general, but usually about 30 minutes to 20 hours is sufficient, preferably about 1 to 10 hours. is there.
Thus, by using a zeolite and / or montmorillonite catalyst from which adhering moisture has been removed, α-olefin is internally isomerized at a conversion rate of 90% or more, preferably 94% or more, under relatively mild conditions. Can do.
In addition, since undesirable side reactions such as catalyst deterioration, skeletal isomerization reaction products, and heavy reaction can be suppressed, a desired internal olefin can be selectively obtained.
Moreover, the production rate of the skeletal isomerization reaction product is usually 3% by mass or less, preferably 2% by mass or less, and the production rate of the heavy reaction product is usually 2% by mass or less, preferably 1.5% by mass. % Or less.
In addition, since the reaction product solution can be made into a product without being purified by distillation, a distillation column for removing heavy reaction products and the like is not necessary, which is highly economical.
In addition, since the zeolite and / or montmorillonite-based catalyst used in the present invention is generally inexpensive, a sufficiently economical process can be designed even if the catalyst is replaced.
Furthermore, although the activity of the catalyst used in the present invention is usually reduced due to the attachment of the heavy reaction product, it can be regenerated by calcination at 400 to 500 ° C. under an air flow. The nature becomes even higher.

  The internal olefin mixture having 16 to 18 carbon atoms of the present invention obtained as described above has a straight chain ratio as high as 90%, preferably as high as 92% or more, has a controlled double bond distribution, and is used for oil drilling. It is suitably used as a base oil.

EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited at all by these examples.
Example 1
A stainless steel reaction tower (length: 1.1 m, inner diameter: 10 mm) having a diameter of 12 mm is filled with 50 ml of HMFI-90 (manufactured by Zude Chemie, proton-type MFI zeolite catalyst), and nitrogen gas is allowed to flow at 100 ml / min. Pretreatment was performed for 24 hours to remove water adhering to the catalyst.
At this time, the dew point of nitrogen gas at the inlet of the reaction tower was −60 ° C., and the dew point of nitrogen gas at the outlet of the reaction tower at the end of pretreatment was −40 ° C.
Next, after setting the temperature of the reaction tower to 100 ° C., a mixture of 70% by mass of α-olefin having 16 carbon atoms / 30% by mass of α-olefin having 18 carbon atoms was supplied in an upward flow at 100 ml / hour.
The reaction was continued while raising the reaction temperature as the catalyst activity decreased so that the conversion of α-olefin was 93 to 95% or more.
The reaction was stopped because the reaction temperature rose to 175 ° C. when 400 hours had elapsed from the start of the supply of the α-olefin mixture.
The double bond isomerization conversion rate of α-olefin at the end of the reaction was 94.5%, the production rate of the heavy reaction product was 1.8% by mass, and the production rate of the skeletal isomerization product was 0. It was 9 mass%.
Moreover, the linear ratio (ratio of linear olefin) of the production | generation internal olefin was 92%, and the difference with raw material alpha-olefin was not seen.
The linearity was quantified by gas chromatography after hydrogenating the reaction product.

Example 2
After the reaction of Example 1 was stopped, the catalyst was extracted from the reaction tower and calcined using air at about 400 ° C. for 24 hours in a muffle furnace.
The regenerated catalyst was charged again into the reaction tower of Example 1, and the reaction was performed in the same manner as in Example 1 except that the dew point of the nitrogen gas at the outlet of the reaction tower at the end of the pretreatment was -45 ° C.
When 420 hours had elapsed from the start of the supply of the α-olefin mixture, the reaction temperature was 175 ° C., so the reaction was stopped.
The double bond isomerization conversion rate of α-olefin at the end of the reaction was 94.8%, the production rate of the heavy reaction product was 1.9% by mass, and the production rate of the skeletal isomerization product was 1. It was 0.0 mass%.
Moreover, the straight chain ratio of the produced | generated internal olefin was 92%, and the difference with the raw material alpha olefin was not seen.

Example 3
The reaction was performed in the same manner as in Example 1 except that the dew point of the nitrogen gas at the exit of the reaction tower at the end of the pretreatment was -50 ° C.
When 420 hours had elapsed from the start of the supply of the α-olefin mixture, the reaction temperature was 175 ° C., so the reaction was stopped.
The double bond isomerization conversion rate of α-olefin at the end of the reaction was 94.6%, the production rate of heavy reaction product was 1.7% by mass, and the production rate of skeletal isomerization product was 0. It was 9 mass%.
Moreover, the straight chain ratio of the produced | generated internal olefin was 92%, and the difference with the raw material alpha olefin was not seen.

Comparative Example 1
The reaction was performed in the same manner as in Example 1 except that the dew point of the nitrogen gas at the outlet of the reaction tower at the end of the pretreatment was −30 ° C.
Since the reaction temperature reached 175 ° C. after 270 hours from the start of the supply of the α-olefin mixture, the reaction was stopped.
The α-olefin double bond isomerization conversion rate at the end of the reaction was 95.0%, the production rate of the heavy reaction product was 1.9% by mass, and the skeletal isomerization product rate was 1. It was 0.0 mass%.
Moreover, the straight chain ratio of the produced | generated internal olefin was 92%, and the difference with the raw material alpha olefin was not seen.

Comparative Example 2
The reaction was performed in the same manner as in Example 1 except that the dew point of the nitrogen gas at the exit of the reaction tower at the end of the pretreatment was −10 ° C.
Since the reaction temperature reached 175 ° C. after 200 hours had elapsed from the start of the supply of the α-olefin mixture, the reaction was stopped.
The double bond isomerization conversion rate of α-olefin at the end of the reaction was 94.8%, the production rate of the heavy reaction product was 1.8% by mass, and the production rate of the skeletal isomerization product was 1. It was 0.0 mass%.
Moreover, the straight chain ratio of the produced | generated internal olefin was 92%, and the difference with the raw material alpha olefin was not seen.
The above results are summarized in Table 1.

From Table 1, Examples 1 to 3 have a catalyst life of 1.5 to 2 times that of Comparative Examples 1 and 2 because the dew point of the nitrogen gas at the outlet of the reaction tower at the end of the pretreatment is low.
On the other hand, Comparative Examples 1 and 2 have a short catalyst use period because the dew point of the reaction tower outlet nitrogen gas at the end of the pretreatment is high.

According to the present invention, a product with higher performance than before can be obtained, and the life of the catalyst can be extended, so that production energy is greatly reduced, and energy saving in industrial production is expected.

Claims (6)

  In the method for producing an internal olefin by isomerizing an α-olefin having 16 to 18 carbon atoms in the presence of a zeolite and / or a montmorillonite catalyst, dry air or nitrogen having a dew point of −50 ° C. or less in advance is added to the catalyst layer. Circulate at a temperature of ℃ or higher, remove the water adhering to the catalyst until the dew point of the catalyst layer outlet gas is -40 ℃ or less, and then isomerize the α-olefin having 16 to 18 carbon atoms at a temperature of 70 to 175 ℃ And a method for producing internal olefins.   2. The internal structure according to claim 1, wherein the conversion rate of α-olefin is 90% or more, the production rate of the heavy reaction product is 3% by mass or less, and the production rate of the skeletal isomerization product is 2% by mass or less. Production method of olefin.   The method for producing an internal olefin according to claim 1 or 2, wherein the zeolite catalyst is MFI type zeolite.   The method for producing an internal olefin according to any one of claims 1 to 3, wherein the content of the α-olefin having 18 carbon atoms in the α-olefin is 20 to 35 mass%.   The C16-C18 internal olefin mixture obtained by the method in any one of Claims 1-4. An oil drilling base oil comprising the internal olefin mixture having 16 to 18 carbon atoms according to claim 5.