RU2737261C1 - Method of increasing activity of regenerated catalyst for hydrofining of hydrocarbon material - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: invention relates to methods of increasing catalyst activity, spent mileage, unloaded and subjected to regeneration of a catalyst for hydrofining oil stock. Disclosed is a method of increasing activity of a regenerated catalyst for hydrofining hydrocarbon material by impregnating the regenerated catalyst with an organic carboxylic acid solution with two additives, further aging under vacuum for 1–36 hours at temperature of 30–150 °C, subsequent drying in inert gas at 100–150 °C for 1–16 hours and calcination (if necessary) in inert gas at 400–600 °C for 1–5 hours.EFFECT: technical result is obtaining an activated hydrotreating catalyst with activity of more than 98 %, high strength and long service life.4 cl, 4 tbl, 2 ex

Description

The invention relates to methods for increasing the activity of a catalyst that has spent its run, unloaded and passed the catalyst regeneration procedure.

During the hydrotreating of crude oil, the catalyst is gradually deactivated. The main role in this process is played by sulfur compounds, resinous-asphaltene substances and metals. A deactivated catalyst can be either reversible or irreversible. Metals inevitably poison the catalyst. Polycyclic aromatic hydrocarbons and resinous-asphaltene substances in the process of hydrotreating condense and turn into coke-forming substances, which are deposited on the catalyst, deactivating it. These substances can be removed by burning off coke - carrying out regeneration of catalysts.

Regeneration of catalysts allows you to restore the activity of the catalyst to 85% of the fresh one. In order to increase the activity of the regenerated catalysts, after the regeneration, the process of increasing the activity of the catalysts is carried out, characterized by the treatment of the regenerated catalyst with various activating agents, followed by drying or calcination.

From the existing technical level known method RU No. 2035223 "Method of reactivation of spent catalyst for hydrotreating of petroleum fractions". The spent hydrotreating catalyst is calcined in a rotary drum furnace in the presence of 10-15% water vapor, at 500-600 ° C for 2 hours, with its further treatment with nitric or acetic acid at pH 2.5-5.0.

The disadvantage of this method is the absence of a drying and calcining stage after the treatment with nitric and acetic acid, which leads to a loss of strength, destruction and rapid loss of activity during the subsequent operation of the catalyst.

The closest to the claimed technical solution is the method RU No. 2351634, in which an unregenerated hydrotreating catalyst containing a Group VIB metal oxide and a Group VIII metal oxide is regenerated in the first stage in an oxygen-containing gas at a temperature of 100 to 370 ° C. At the second stage of regeneration, the catalyst is calcined from 300 to 650 ° C, the layer thickness is 1-15 cm. The regenerated catalyst is directed to impregnation of a mixture of acid and organic additive with a boiling point of 80-500 ° C. The product is then subjected to an aging step for 1, 2 or 6 hours (aging time is a function of temperature). If necessary, the catalyst is dried to remove excess moisture.

The disadvantage of this method is the insufficiently high hydrodesulfurizing and hydrogenating activity of the catalyst. This is due to the fact that when the catalyst is dried in the presence of an organic additive, in oxygen flows, the initial structure of modifying additives changes. Due to the long duration of the aging process, there is a loss of strength characteristics of the catalyst and a subsequent decrease in its service life.

The objective of the present invention is to develop a method for increasing the activity of a regenerated catalyst for hydrotreating petroleum products with increased hydrodesulfurizing and hydrogenating activities, maintaining the strength characteristics and service life of the catalyst.

This problem is solved by a method of increasing the activity of the regenerated catalyst for hydrotreating hydrocarbon feedstock, by impregnating the regenerated catalyst with an acid solution with several additives, further aging in an isolated state under vacuum for 1-36 hours (6 hours, preferably 12 hours, preferably 18 hours, depending on the type catalyst) at a temperature of 30-150 ° C, followed by drying in an inert gas at 100-150 ° C for 1-16 hours and (or) calcining in an inert gas at 400-600 ° C for 1-5 hours.

Regeneration of catalysts to remove coke from spent catalyst can be accomplished in any convenient manner. During regeneration, the catalyst is in contact with a gas containing oxygen at elevated temperatures. Depending on the type of catalyst and the type of regeneration, temperatures from 300-350 ° C to 450-500 ° C are preferred.

The regenerated catalyst is impregnated with a mixture of acid and additives. Organic acids are the preferred class of complexing agents for use in the impregnation solution.

Organic acids suitable for our invention are organic compounds whose molecules contain one or more carboxyl groups, COOH. These substances are most strongly acidic.

The main carboxylic acids suitable for our invention are monobasic: formic HCOOH, acetic CH ₃ COOH, propionic C ₂ H ₅ COOH, butyric C ₃ H ₇ COOH, valeric C ₅ H ₁₁ COOH, nylon C ₆ H ₁₃ COOH, palmitic C ₁₅ H ₃₁ COOH, stearic C ₁₇ H ₃₅ COOH. The most preferred are dibasic organic acids: oxalic HOOC-COOH, malonic HOOC-CH ₃ -COOH, succinic HOOC- (CH ₂ ) ₂ -COOH, glutaric HOOC- (CH ₂ ) ₃ -COOH, adipic HOOC- (CH ₂ ) ₄ -COOH, pimelic HOOC- (CH ₂ ) ₅ -COOH, suberic HOOC- (CH ₂ ) ₆ -COOH, azelaic HOOC- (CH ₂ ) ₇ -COOH, sebacic HOOC- (CH ₂ ) ₈ -COOH, etc. ... Hydroxy acids having two functional groups: OH (hydroxyl) and COOH (carboxyl) can be used as an acid in the impregnating solution, such as lactic acid CH ₃ -CH (OH) -COOH, malic acid HOOC-CH ₂ -CH (OH ) -COOH, wine HOOC-CH (OH) -CH (OH) -COOH, lemon (HOOC-CH ₂ ) ₂ -C (OH) -COOH, quinine C ₇ H ₁₂ O ₆ .

In the present invention, the additive can be a compound containing from 2 to 10 carbon atoms and 2 oxygen atoms. Compounds such as polyols, glycols and ethers, aldehydes or ketones. Examples of such additives include glyoxal, glycerin, ethylene glycol, triethylene glycol, polyethylene glycol, diethylene glycol, propylene glycol, monoethyl ether, diethyl ether, methylphenyl ether, etc.

Other compounds used as additives are at least two nitro hydrogen atoms and 2-10 carbon atoms: ethylenediamine, propylene diamine, 1,3-diaminobutane, 1,3-pentanediamine, etc.

The third group of additives includes compounds having one oxygen atom and one nitrogen atom, such as: ethanolamine, diethanolamine and triethanolamine, etc.

A distinctive feature of the invention is the presence of two additives and an acid in the impregnating solution. It was found that the use of two additives with acid in one impregnating solution markedly increases its hydrodesulfurizing and hydrogenating activities.

After impregnation with the solution, the aging procedure is carried out for 1-36 hours under vacuum at a temperature of 30-150 ° C, followed by drying in an inert gas at 100-150 ° C for 1-16 hours and (or) calcining in an inert gas at 400- 600 ° C for 1-5 hours.

A distinctive feature of the present invention is the aging of the catalyst under vacuum, as well as drying and calcining the impregnated catalyst in an inert gas, instead of normal air. This makes it possible to increase the hydrodesulfurizing activity of the catalyst, its strength and service life.

For the invention, the following inert gases can be used: nitrogen, argon, and flue gases with a low moisture and oxygen content

The technical result provided by the above set of features is an activated hydrotreating catalyst with an activity of more than 98%, high strength and service life.

The essence of the invention is illustrated by the following examples.

Example 1

The regenerated catalyst has the following characteristics: S - 0.060% by weight; C - 0.309% weight; Specific surface area - 202 m ² / g; Average diameter - 1.33 mm; Average particle length - 2.940 mm; Bulk density 0.88 g / cm ³ ; The pore volume is 0.47 cm ³ / g; Abrasion strength 95.07; Bulk strength 1.37 MPa.

Prepare an impregnating solution

100% oxalic acid at a concentration of 0.08 mol per mole of Al ₂ O ₃ , polyethylene glycol in an amount equal to 4% by weight of the final catalyst and diethanolamine in an amount of 10% by weight of the final catalyst, are mixed with water, thus obtaining a solution for impregnating the regenerated catalyst ...

The catalyst is impregnated with the resulting solution. The impregnated catalyst is aged for 8 hours under vacuum. Heat treatment is carried out: drying in nitrogen at a temperature of 140 ° C for 2 hours. The catalyst is cooled to 30 ° C.

To obtain comparative data, part of the impregnated catalyst after aging is dried in air at 140 ° C for 2 hours. Then it is cooled to 30 ° C.

The activated catalyst, dried in an inert gas, has the following characteristics: S - 0.272% by weight; C - 5.48% by weight; Specific surface area - 200 m ² / g; Average diameter - 1.32 mm; Average particle length - 2.83 mm; Bulk density 0.89 g / cm ³ ; Abrasion strength 96.15% of the mass; Bulk strength 1.38 MPa.

The activated catalyst, dried in air, has the following characteristics: S - 0.272% by weight; C - 5.48% by weight; Specific surface area - 200 m ² / g; Average diameter - 1.32 mm; Average particle length - 2.83 mm; Bulk density 0.89 g / cm ³ ; Abrasion strength 94.37% of the mass; Bulk strength 1.34 MPa.

The results of testing the activity of the regenerated, activated air-dried and activated inert gas-dried catalyst are shown in Table 1.

According to the results of analyzes and the results obtained, it can be seen that the activity of the activated catalyst in air is 97.0% higher than that of the regenerated one, 92.4%, and the activity of the activated catalyst in an inert gas is 98.4%, which is even higher than in air. The catalyst activation technology according to the technology of this invention made it possible to increase the catalyst activity up to 98.4%

In addition, as can be seen from Table 2, the activation by this invention, by drying and calcining the catalyst in an inert gas, made it possible to maintain the strength after the activation, therefore, to extend its service life.

Example 2

The regenerated catalyst has the following characteristics: S - 0.330% by weight; C - 0.14% by weight; Specific surface area - 189 m ² / g; Average diameter - 1.37 mm; Average particle length - 2.52 mm; Bulk density 0.92 g / cm ³ ; The pore volume is 0.43 cm ³ / g; Abrasion strength 95.04; Bulk strength 1.32 MPa.

An impregnating solution is prepared:

Acetic acid at a concentration of 9 mol / L, diethylene glycol monoethyl ether at a concentration of 2 mol / L and ethanolamine at a concentration of 5 mol / L are mixed with water.

The catalyst is impregnated with the resulting solution. The impregnated catalyst is aged for 12 hours under vacuum. Heat treatment is carried out: drying in nitrogen at a temperature of 150 ° C for 2 hours. The catalyst is cooled to 30 ° C.

To obtain comparative data, part of the impregnated catalyst after aging was dried in air at 150 ° C for 2 hours. Then it is cooled to 30 ° C.

The activated catalyst, dried in an inert gas, has the following characteristics: S - 0.161 wt%; C - 0.07% weight; Specific surface area - 190 m2 / g; Average diameter - 1.32 mm; Average particle length - 2.54 mm; Bulk density 0.43 g / cm3; Abrasion strength 97.16% of the mass; Bulk strength 1.33 MPa.

The activated catalyst, dried in air, has the following characteristics: S - 0.161 wt%; C - 0.07% weight; Specific surface area - 190 m ² / g; Average diameter - 1.32 mm; Average particle length - 2.54 mm; Bulk density 0.43 g / cm ³ ; Abrasion strength 95.45% of the mass; Bulk strength 1.30 MPa.

The results of testing the activity of the regenerated, activated air-dried and activated inert gas-dried catalyst are shown in Table 3.

According to the results of analyzes and the results carried out, it follows that the activity of the activated catalyst in air is 97.8% higher than that of the regenerated one, 90.1%, and the activity of the activated catalyst in an inert gas is 99.9%, which is even higher than in air. The catalyst activation technology according to the technology of this invention made it possible to increase the catalyst activity up to 99.9%. In addition, activation by this invention, by drying and calcining the catalyst in an inert gas, made it possible to maintain the strength after the activation, therefore, to extend its service life. Data on the effect of activation of the regenerated catalyst on its strength are presented in Table 4.

Claims (4)

1. A method of increasing the activity of a regenerated catalyst for hydrotreating hydrocarbon feedstock by impregnating the regenerated catalyst with an organic carboxylic acid solution with two additives selected from compounds containing from 2 to 10 carbon atoms and 2 oxygen atoms, compounds containing 2 nitro hydrogen atoms and 2-10 atoms carbon, and compounds having one oxygen atom and one nitrogen atom, in any combination thereof, further aging under vacuum for 1-36 hours at a temperature of 30-150 ° C, followed by drying in an inert gas at 100-150 ° C for 1-16 hours, followed by calcining (if necessary) in an inert gas at 400-600 ° C for 1-5 hours. 2. The method according to claim 1, characterized in that the aging process is carried out under vacuum for 1-36 hours, after which the drying and calcination processes are carried out. 3. A method according to claim 1, characterized in that a mixture of an acid and two additives is used in the impregnating solution. 4. The method according to claim 1, characterized in that drying and calcining (if necessary) of the catalyst is carried out in an inert gas.