JPH02247287A - Production of aromatic-containing solvent - Google Patents

Abstract

PURPOSE:To obtain the subject solvent, having a low mixed aniline point and excellent in solubility at a low production cost by catalytically reforming a kerosene fraction according to a continuous regeneration method and then distilling, separating and recovering a specific fraction from the resultant product. CONSTITUTION:A kerosene fraction or a raffinate obtained after recovering n-paraffins therefrom is catalytically reformed by using a continuous regeneration type catalytic reforming method for circulating a catalyst between a reaction column and regeneration column and repeating reforming reaction and catalyst regeneration and a fraction having the boiling point within the range of 185-220 deg.C is distilled, separated and recovered from the resultant formed oil to afford the objective solvent having <=21 deg.C mixed aniline point.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing an aromatic-containing solvent by reforming a kerosene fraction or the like by a continuous regeneration catalytic reforming method.

[Prior Art] A fraction with a boiling point in the range of 185 to 220°C and mainly consisting of aromatic components is used as a solvent for baking paints using phenolic resins, alkyd resins, urea resins, melamine resins, acrylic resins, etc. It is also used as a thinner, a cleaning solvent for metal parts, an emulsion for agricultural chemicals, an oil compounding agent for machinery, and a solvent for reaction systems. These solvents are required to have a mixed aniline point of 21° C. or lower from the viewpoint of solubility.

Conventionally, this type of solvent has been recovered from coal tar oil, or by mixing ethylene cracker bottoms with 09 heavy oil (a fraction with a carbon number of 9 or more recovered from reformed oil obtained from a naphtha reforming reaction). It is produced by hydrogenation treatment, alkylation of naphthalene, dinuclearization of monocyclic aromatic compounds, etc. These methods generally have the problem of high manufacturing costs.

By the way, it has been reported that catalytic reforming of kerosene fractions produces fractions containing aromatic components [
Journal of the Japan Petroleum Institute, Vol. +3. No. 6 (1970),
P468-474]. However, this report states that 21℃
There is no disclosure that a 185-220° C. fraction having the following mixed aniline points is obtained.

[Problems to be Solved by the Invention] As a result of intensive research in view of the above-mentioned current situation, the present inventor found that when a kerosene fraction is subjected to a reforming reaction, the catalyst deteriorates significantly over time. 18 which has a mixed aniline point below 21°C only for a very short period of time.
A distillate with a boiling point range of 5 to 220°C can be obtained, and in industrial production, the catalyst must be replaced frequently, which is a cost issue. When the catalyst is regenerated, the activity almost completely returns, and it has been found that even with this regenerated catalyst, a fraction having the mixed aniline points can be produced from a kerosene fraction.

The present invention was made based on this knowledge, and aims to solve the above-mentioned problems and produce a high-boiling point, highly aromatic-containing solvent with a mixed aniline point of 21°C or less and excellent solubility at a low manufacturing cost. The purpose is to provide a method.

[Means for solving the problem]- The present invention uses a continuous regeneration type catalytic reforming method in which a catalyst is circulated between a reaction tower and a regeneration tower and a reforming reaction and catalyst regeneration are repeated. Alternatively, it consists of catalytically reforming the raffinate after recovering normal paraffin from a kerosene fraction, and distilling and recovering a fraction in the boiling point range of 185 to 220° C. from the resulting oil.

The continuous regeneration type catalytic reforming method referred to in the present invention means that the particle size is 0.
．． A spherical reforming catalyst of 5 to 4.0 mm is circulated between a reaction tower and a regeneration tower, and it is preferable that both the reaction tower and the regeneration tower are operated using moving beds. In addition, the reaction tower and regeneration tower are
A double tube having a common axis with the base axis and having pores large enough to prevent the catalyst from leaking is provided, and the catalyst is moved between the pores by gravity from top to bottom, and in a direction across the moving catalyst. A structure that allows the reaction fluid to flow is preferable in terms of reaction efficiency. In this case, the regeneration tower has an area where coke is burned with oxygen-containing gas, an area where the catalyst is treated with halogen such as chlorine, and a lower part of the regeneration tower to prevent combustion gas from entering the reaction tower. It is preferable to use a reactor equipped with a degassing region, a reducing region for reducing the catalyst with a reducing gas such as hydrogen, and a device for transferring the catalyst to the reaction tower. In this case, the regeneration is 450 to 550 for coke combustion.
℃, 500-550℃ for chlorination, 380-550℃ for reduction
When carried out in the temperature range of 520℃, it is easy to
It is preferable that it can be completely regenerated. Moreover, the pressure of the regeneration tower is 0.
It is best to do this at 01 to 5 kg/cntG. On the other hand, since the reforming reaction is an endothermic reaction, the reaction tower divides the contact zone of the reaction fluid into about 2 to 4 stages, and heats the outflow from the first stage reaction zone to perform the second stage reaction. It is preferable to adopt a method of causing the reaction by passing through a reaction zone while heating in the following manner.

The kerosene fraction used as raw material oil in the present invention refers to a fraction distilled in a temperature range of 150 to 300°C by distillation separation operation, and includes straight-run kerosene fraction obtained by atmospheric distillation of crude oil. It goes without saying that it is also possible to use fractions of petroleum, such as fractions with the boiling point ranges mentioned above, obtained by thermal cracking, catalytic cracking, hydrocracking, alkylation, and other refining treatments of residues. This kerosene fraction preferably has a sulfur content and a nitrogen content of 50 ppm or less.

This is a commonly used hydrodesulfurization treatment method that uses a catalyst supporting one or more of cobalt, nickel, molybdenum, tungsten, etc. on a support such as alumina or silica-alumina under normal desulfurization conditions. , 250
Use desulfurized oil desulfurized under the conditions of a temperature of ~430°C, a pressure of lO~200kg/ctd, a liquid hourly space velocity (LH3V) of 0.1~l5h, and a hydrogen circulation rate of 50~140ON/'k12. is preferred.

In the present invention, in addition to the above-mentioned kerosene fraction, a raffinate obtained by recovering normal paraffin from this kerosene fraction may be used, and in this case, the reforming reaction conditions can be made mild.

This normal paraffin can be removed using an adsorption separation method using zeolite or a separation method using a urea adduct. It is sufficient that this raffinate is one in which normal paraffin is collected and removed at a recovery rate of about 50 to 95%.

On the other hand, as a catalyst for the reforming reaction, catalysts used in the catalytic reforming method of naphtha fractions include, for example, platinum supported on alumina, or rhenium, germanium, soot, iridium, ruthenium, etc. in addition to platinum. things, or
Zeolite or crystalline aluminosilicate, silica, alumina, zirconia, titania, chromia, solid phosphoric acid, or oxides of indium, lanthanum, manganese, cerium, tin, etc. used in the dehydrocyclization reaction of hydrocarbons, or , acidic refractories containing a mixture of two or more of these, or platinum, palladium,
A material containing or supporting metals such as rhenium can be used.

In addition, the reforming reaction conditions are similar to those of the catalytic reforming method, which is generally used as a method for producing high octane gasoline from naphtha fraction, etc., such as 400 to 550 °C.
temperature, pressure of 1 to 50 kg/Cml, liquid hourly space velocity (L
, HSV)O,i~3h-', hydrogen/oil molar ratio 0.
It is appropriately selected in the range of 5 to 20. In particular, the reaction temperature is 490 to 550°C, and the hydrogen pressure is 1 to 15 kg/cT.
IIC, liquid hourly space velocity (L) (SV) of 0.1 to 1,
If selected in the range of 2h-”, the mixed aniline point will be 21°.
It is possible to increase the yield of a solvent having a boiling point range of 185 to 220° C. and is more preferred.

From the produced oil obtained as above, 185-220
By distilling and collecting fractions in the range of °C,
A solvent with a high aromatic content and a mixed aniline point of 21° C. or lower can be obtained as a product.

The mixed aniline point is measured by the method specified in JISK, 2256 "Petroleum products aniline point and mixed aniline point testing method".

"Example" (Experiment Examples 1 and 2) Using a desulfurized kerosene fraction having the properties shown in Table 1 obtained by hydrodesulfurizing a kerosene fraction and zeolite from this kerosene fraction, 90% by weight of normal paraffin was recovered. Raffinate having the properties shown in Table 1 is used as raw material, and platinum is added to 0.
．． Using a catalytic reforming catalyst with 2% by weight of alumina supported, the reaction temperature was 500°C and the reaction pressure was 8 kg/crl.
The reforming reaction was carried out under the conditions of a hydrogen/raw oil molar ratio of 3. A fraction at 195 to 215°C was distilled and separated from the produced oil on the first day of operation. The properties are shown in Table 2.

Table 1 Table 2 The fraction between 95 and 215°C was separated by distillation, and changes in the yield and mixing point of aniline of this fraction were measured, as well as the amount of coke deposited on the catalyst after the reaction was completed. . These results are shown in Table 3.

Table 3 (Experimental Examples 3 to 4) A reforming reaction was carried out under the same conditions as in Experimental Examples 1 and 2 above for 5 days, and on the 3rd and 5th day, 1 (Experimental Example 5) The catalyst obtained in step 3 was heated at 500 °C in an air atmosphere.
℃ temperature for 4 hours, and then at a temperature of 450℃,
After exposing the system to a chlorine-air mixture gas with a concentration of 0.61% and replacing the system with nitrogen, hydrogen gas was flowed and the temperature was 510°C.
Time was saved. Using this catalyst, a reforming reaction was carried out for 3 days under the same conditions as in Experimental Example 1, using desulfurized kerosene as a raw material.

Table 4 shows the yield and mixed aniline point of the 195-215°C fraction obtained on the third day. Furthermore, the reforming reaction and catalyst regeneration were repeated 10 times using the three-day period as a cycle. The measurement results of the yield and the mixed aniline point on the third day at a predetermined number of times are also shown in Table 4.

Table 4 shows that even deteriorated catalysts can be almost completely regenerated by combustion.

[Effects of the Invention] The present invention uses a continuous regeneration reforming method to perform a reforming reaction on kerosene fractions, etc., so it can be produced at low manufacturing cost and has a high solubility that has a mixed aniline point of 21°C or less. It has the special effect of being able to produce aromatic solvents.

Claims (2)

[Claims] (1) The kerosene fraction is catalytically reformed using a continuous regeneration type catalytic reforming method in which the catalyst is circulated between the reaction tower and the regeneration tower and the reforming reaction and catalyst regeneration are repeated. ~22
A method for producing an aromatic-containing solvent having a mixed aniline point of 21° C. or lower, which comprises distilling and recovering a fraction with a boiling point range of 0° C. (2) Using a continuous regeneration catalytic reforming method in which the catalyst is circulated between the reaction tower and the regeneration tower and the reforming reaction and catalyst regeneration are repeated, the raffinate after normal paraffin has been recovered from the kerosene fraction is catalytically reformed. 185-220 from the produced oil
A method for producing an aromatic-containing solvent having a mixed aniline point of 21° C. or lower, which comprises distilling and recovering a fraction having a boiling point range of 21° C.