RU2035223C1 - Method for reactivation of used catalyst for hydraulic treatment of oil fraction - Google Patents

Abstract

FIELD: oil-producing industry. SUBSTANCE: used catalyst is burnt in rotary drum furnace in presence of 10-15% of water vapor at 500-600 C for 0.5-2.0 h followed by treating it with nitric or acetic acid at pH 2.5-5.0. EFFECT: higher efficiency. 1 tbl

Description

 The invention relates to methods for reactivation (regeneration) of oil refining and petrochemical catalysts.

A known method of regeneration of alumina-cobalt-molybdenum catalyst [1] aimed at removing from the catalyst a plaque of iron and its compounds deactivating the catalyst. The spent catalyst, previously calcined in a stream of a mixture of water vapor and air and cooled, is washed with a stream of water, transferred to mesh baskets, in which it is repeatedly washed cold water until a clean wash water is obtained and the metallic surface of the catalyst returns, then it is dried for 1.5 days in the sun and the catalyst is returned, including 16% of the water in the reactor. For removing water, the catalyst was heated in a nitrogen atmosphere from 25 to 200 ^{° C} for 44 hours to achieve dew point 22 ^{° C} in N _2. The catalyst regenerated in this way is characterized by a specific surface area of 160 m ² / g (fresh catalyst 180 m ² / g), a pore volume of 0.62 ml / g (0.63 mg / l), activity at the hydrogenation stage of 97.8% 300 ^о С . 98.6% and 340 ^C (fresh catalyst was 98.8% and 300 ^{° C} 98.9% 340 ^{° C,} in step desulfurization 97.5% (97.5%) molybdenum content is reduced from 5 to 4; Co from 1.5 to 0.5%, the Co / Mo ratio in the catalyst is from 0.3 to 0.1. The method allows the catalyst to be regenerated with physicochemical characteristics and reactivity not inferior to the catalyst regenerated by a sieve Fe-th separator impurities and further eliminates pollution Fe-waste.

 The disadvantage of this method is the need for repeated washing of the catalyst and a large amount of wastewater.

Known process for regenerating hydrodesulfurization catalysts [2] The exhaust, containing A _l2 O ₃ and Ni and deactivated compounds V hydrodesulfurization catalyst sulfided with H ₂ S 400-700 ^o C (556 ^o C) and supplying H ₂ S ≥ 60 ml / g of catalyst, and -coli then leached at a temperature required to remove an effective amount of V and Ni, and increasing the diameter of pores of the catalyst and its surface (at ¹⁰⁰ ° C for 20 min) the acidic aqueous Fe ⁽³⁺⁾ solution. Better pre-spent catalyst wash solvent, followed by dispersion, drying and calcining at 400 ° ^C.

A known method of regenerating spent industrial Ni-Mo catalyst used for hydrotreating petroleum feeds. It was shown that the controlled calcination of spent catalysts (at Т ≅ 480 ^о С) followed by impregnation with aqueous solutions of Ni (NO ₃ ) ₂ and (NH ₄ ) ₂ MoO ₄ , drying and calcination in air provides good catalyst regeneration and allows obtaining a catalyst with activity approaching the value observed for the starting catalysts [3] The disadvantage of these methods is the inability to remove impurities of sodium and iron.

Known process for regenerating Fe-containing hydrocarbon processing catalyst [4] The spent catalyst containing up to 35% carbon, 30% sulfur, and 1-1.5% of vanadium, was subjected to heat treatment at ≅ 400 ^{° C} for 8 hours in air the presence of metal carbonate (Na, K) to remove coke. This gives a catalyst containing Fe ₂ O ₃ and water-soluble salts of sulfur and vanadium. This catalyst is sent to a water washing step to remove sulfur and vanadium salts. Rinsing is carried out until neutral wash water is obtained. The catalyst is fed to a separator, where solid Fe ₂ O _{3 is} separated and sent for drying, and the liquid is fed for regeneration using CO ₂ to produce metal carbonate. The disadvantages of this method is the presence of a large amount of wastewater and the complexity of the technology.

. На 2-й стадии проводят нагрев до температуры 650-815^оС и выдерживают при этой температуре в течение 1-5 ч с целью увеличения среднего размера пор. Удельная поверхность регенерированного таким образом катализатора составляет 20-200 м²/г, удельный объем пор 0,2-0,8 см³/г, средний диаметр пор 50-200

, причем 50% объема пор приходится на поры с диаметром 60-300

. Недостатком известного способа является недостаточная глубина удаления соединений железа и натрия.The closest known solution to a similar problem in terms of technical nature and the achieved effect is a method for regenerating a hydrotreating catalyst [5]. A method for regenerating a spent hydrotreating catalyst is proposed, which is a 2-stage process, after which a regenerated catalyst can be used in hydrotreating of metal-containing oils. At the 1st stage, the spent catalyst (coked with Mo, W, Ni or Co deposited on Al ₂ O ₃ ) is heated to a temperature of 370-540 ^о С in an oxygen-containing atmosphere in order to remove coke deposits. This gives a material characterized by the following data: specific surface area 50-300 m ² / g, specific pore volume 0.2-1.0 cm ³ / g, average pore diameter 40-150

. In the 2nd stage heating is conducted to a temperature of 650-815 ^C and maintained at this temperature for 1-5 hours to increase the average pore size. The specific surface area of the catalyst thus regenerated is 20-200 m ² / g, the specific pore volume is 0.2-0.8 cm ³ / g, the average pore diameter is 50-200

moreover, 50% of the pore volume falls on pores with a diameter of 60-300

. The disadvantage of this method is the insufficient depth of removal of compounds of iron and sodium.

 The main objective of the proposed solution is the complete burning of residual coke due to calcination in the presence of water vapor, removal of iron and sodium compounds, which leads to an increase in the stable activity of the catalyst.

The proposed method for reactivating spent hydrotreating catalyst comprises petroleum fractions catalyst calcination in a rotary drum furnace in the presence of 10-15% water vapor at a temperature of 500-600 ^{° C} for 0.5-2.0 hours followed by treating it with nitric acid or acetic acid at pH 2.5-5.0.

 In this case, the best contact of the surface of the granules with the oxidizing medium occurs. Calcination is carried out in a drum furnace with dividing sections. After the calcination zone passes, the catalyst through the system of hoppers, conveyors and elevators can be returned to the drum furnace to repeat the operation. The purpose of processing the catalyst granules with a solution of nitric or acetic acid is to restore the active phase of the metals. When processing catalyst granules with an acid solution at pH 2.5-5.0, the specific surface area of the catalyst increases due to a more complete removal of residual coke from the narrow pores of the granules.

Comparative analysis of the inventive solutions with the prototype shows that the proposed method differs from the known fact that the reactivation of the spent hydroprocessing catalyst alyumonikelmolibdenovogo performed by calcining it in a rotary drum furnace at a temperature of 500-600 ^{° C} for 0.5-2.0 hours followed by treatment with granules with nitric or acetic acid at pH 2.0-5.0. Thus, the claimed method meets the criteria of the invention of "novelty."

PRI me R 1. Spent catalyst (NiO 4.5% MoO ₃ 13.0% Na ₂ O 1.2% Fe ₂ O ₃ 1.3% specific surface 90 mg / g, K _pr 1.8 kg / mm) in an amount of 100 kg is dried in a rotary drum dryer to wipe the granules against each other. In this case, iron compounds are removed from the outer surface of the granules. Then stepwise temperature in the dryer was increased to 500 ° ^C under a steam flow of 12% for 2 hours. After burning out the residual catalyst coke treated with nitric acid at pH 2.5 and dried with warm air at ¹⁰⁰ ° C for 4 hours. The reactivated the catalyst is screened out from dust and crumbs and packaged in barrels.

PRI me R 2. The spent catalyst is reactivated according to example 1, however, the supply of water vapor is carried out in an amount of 10% at 600 ^about C for 0.5 h and the treatment with acetic acid is carried out at pH 5.0.

PRI me R 3. The spent catalyst is reactivated according to example 1. However, the supply of water vapor in the amount of 15% is carried out at 560 ^about C for 1.0 h and treatment with nitric acid is carried out at pH 3.5.

The obtained catalyst samples were analyzed for the content of iron, sodium and coke, as well as the specific surface was measured and the catalytic activity was determined during the hydrotreatment of diesel fuel (fr. 180-360 ^о С, sulfur content 0.85%) at a pressure of 3.5 MPa volumetric feed rate of 4.0 h ^-1 and a temperature of 360 ^about C. The results are shown in the table.

 From the test results it is seen that the implementation of the reactivation of the proposed method allows to reduce the content of harmful impurities in the catalyst (iron and sodium), remove coke from the surface of the granules and thereby restore the activity of the catalyst sample.

Claims (1)

METHOD OF REACTIVATION OF THE WASTE CATALYST OF HYDROCHINING OIL FRACTIONS by calcining it at elevated temperature, characterized in that the calcination of the catalyst is carried out in a rotary drum furnace in the presence of 10 15% water vapor at 500 600 ^o C for 0.5 2.0 hours followed by its processing nitric or acetic acid at a pH of 2.5 to 5.0.

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