Diesel distillate hydrofining process

FIELD: petroleum processing.

SUBSTANCE: diesel distillates are passed through "filtering" bed composed by ceramic ball bed, which occupies 0.2 to 5.0% of reaction space. Feed is then subjected (i) to hydrofining in presence of catalyst present in the form of contact bed containing alumina-supported molybdenum oxide (2-10%) occupying 0.5 to 10% of reaction space and (ii) to hydrogenation in presence of alumino-nickel-molybdenum and/or alumino-cobalt-molybdenum catalyst. Process is conducted at 340-400 C, pressure 4-10 MPa, volumetric feed supply rate 0.5-3.0 h-1, and hydrogen-containing gas-to-feed volume ratio 400-1200. Invention allows level of sulfur to be lowered to 0.005 wt % or below with amount of polycyclic aromatics being below 11 wt %.

EFFECT: simplified technology and improved quality of product containing negligible quantities of sulfur.

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The invention relates to methods of refining oil distillates, in particular diesel distillates, and can be used in the oil industry.

There is a method of deep hydrogenation of middle oil distillates, allowing you to get from virgin raw materials and distillates of secondary origin deeply dearomatization motor and jet fuel. The hydrogenation process according to the present method is carried out in the presence of sulfide Nickel-tungsten catalyst at a pressure of 25-30 MPa, a temperature of 340-380°C, flow rate of feed of 0.5-1.0 h^-1. (Babikov A.F., Khavkin, VA and other Chemistry and technology of fuels and oils No. 3, 1993, p.34).

The disadvantages of this method is, first of all, the necessity of applying a high pressure of not less than 25 MPa, which significantly increases the cost of the process, namely capital and operating costs, and leads to unnecessarily high costs of hydrogen.

There is a method of refining oil distillates, which consists in the sequential processing of crude oil during Hydrotreating, hydrocracking, hydrodearomatization. The process is carried out at a temperature of 320-380°C, a pressure of 2.5 to 4.5 MPa, the space velocity of the raw material is 1.0-10.0 h^-1, the ratio of hydrogen/feedstock - 300-1000 nm^{3 /m3. The peculiarity of the method is that the ratio of the loading of the catalyst under hydrocracking and hydrodearomatization is 1:9-1:1. The method allows to obtain diesel fuel, characterized by a sulfur content of 0.01 to 0.10 wt.% and aromatic hydrocarbons 5-20 wt.% (Patent RF №2072386, 1997).}

The disadvantages of this method are complex three-stage scheme of processing of raw materials, requiring the use of three different types of catalysts. As the catalyst used in stage Hydrotreating alumina-Nickel(cobalt)-molybdenum contacts containing from 12 to 27 wt.% the molybdate Nickel (cobalt) aluminum oxide; at the stage hydrocracking alumina-Nickel-molybdenum contacts containing from 7 to 20 wt.% the Nickel molybdate on zeolite-containing alumina; at the stage of hydrodearomatization alumina-Nickel-molybdenum contacts, containing from 20 to 35% of the mass. the Nickel molybdate on alumina promoted with phosphorus. Another disadvantage is the relatively low degree of conversion of sulfur compounds (residual sulfur content of below 0.01 wt.%).

Closest to the claimed is a method of obtaining low-sulfur diesel fuel through a three-stage hydrogenation treatment of diesel distillates of various catalysts in the General contour of water is adaderana gas at a hydrogen pressure of 3.0 to 4.8 MPa in the following catalysts: at the stage of hydrogenation of 30-65%, on stage Hydrotreating 10-25%, at the stage of destructive dearomatization 25-45%. (Patent RF №2095395, 1997).

Among the disadvantages of this process is a complex system loaded catalysts: on stage hydrogenation using alumina-cobalt-molybdenum (AKM) and alumina-Nickel-molybdenum (AMN) catalysts, representing two sequentially loaded catalyst consisting of cobalt oxide (Nickel) in an amount of 3-6 wt.%, molybdenum oxide in the number of 16-19 wt.% and alumina - else, on stage Hydrotreating using a catalyst containing 2-5 wt.% oxide of cobalt, 13-20 wt.% molybdenum oxide on alumina; at the stage of destructive dearomatization use a catalyst containing 15-25 wt.% Nickel oxide, 30-50 wt.% molybdenum oxide, 8-15 wt.% silicon oxide, 5-15 wt.% oxide of rare earth elements, aluminum oxide - rest. Only 3 types of catalysts, each of which requires the selection of its implementation process, what complicates the management process. Another disadvantage is the relatively low degree of conversion of sulfur compounds - known method allows to obtain diesel fuel with sulfur content below 0.05 wt.%. In the modern world standards specified content should not exceed 0.005 wt.% and in the future is 0.001 wt.% depending on the type diesel Topley is and. The content of aromatic compounds according to the specified method is less than 20 wt.% (up to 10 wt.%).

The objective of the invention is to develop a method for hydrogenation refining of diesel distillates, allowing for a lower cost to deepen the desulfurization reaction raw materials.

The problem is solved by a method for hydrogenation refining of diesel distillates, including stage Hydrotreating and hydrogenation of the raw material is carried out at elevated temperature and pressure in the presence of a catalyst. The method differs in that the pre-raw materials pass through a "filter" layer, which is a layer of ceramic balls, occupying 0,2-5,0% of the reaction volume, and at the stage Hydrotreating using a catalyst comprising a contact layer containing 2-10 wt.% molybdenum oxide on alumina and occupying 0.5 to 10% of the reaction volume.

Moreover, the process is performed at a pressure of 4-10 MPa, a temperature of 340-400°C, flow rate of feed of 0.5-3.0 hours^-1, the ratio of hydrogen gas/raw 400-1200 rpm./about. using on-stage hydrogenation of alumina-Nickel-molybdenum (AMN) and/or alumina-cobalt-molybdenum (AKM) catalyst.

As catalytic hydrogenation using a catalyst containing 2-5 wt.% oxide of cobalt (or Nickel) and 13-20 wt.% oxide mo is ebden, the rest is aluminum oxide. You can also use both catalyst loading them consistently: AKM - 20% loading and AMN - 80% loading.

Using "filter" layer provides the prior distribution and processing of raw materials (removal of the coke forming compounds, parts of sulfur compounds, solids), and as a "filter" layer apply a much cheaper and affordable material, as compared with the catalysts used in the method according to the prototype of the ceramic balls. As Hydrotreating catalyst used is also relatively inexpensive contact containing 2-10 wt.% molybdenum oxide. The latter is a produced in industry broad porous tablets cheap hydrogenating catalyst. After passing through the catalyst bed Hydrotreating feedstock passes through the core layer catalyst hydrogenation, which is used as the AKM and/or AMN, where the process of deep hydrogenation refining of raw materials.

The method is as follows: raw materials - oil fractions, wikipaedia at temperatures up to 360°C, after heating and mixing with the circulating hydrogen-containing gas into the reactor, where gasasira a mixture of pre-pass "filter" layer - layer to rumichaca balls (diameter of the balls from 6 to 20 mm), occupying 0,2-5,0% of the reaction volume, and then through a bed of Hydrotreating catalyst, which occupies 0.5 to 10% of the reaction volume. Then gasasira mixture layer is the main catalyst for the hydrogenation, which represents an alumina-Nickel-molybdenum and/or alumina-cobalt-molybdenum catalyst.

The proposed method of hydrofining of diesel distillates, you can replace a complex scheme that uses three different types of catalyst, at a cheaper and affordable scheme, instead of using three of expensive catalysts inexpensive filter layer, a relatively inexpensive catalyst for Hydrotreating and catalytic hydrogenation. The method allows to deepen the desulfurization reaction to the level of 0.005 wt.% and less, while the amount of polycyclic aromatic compounds is less than 11 wt.%, which corresponds to the modern requirements for diesel fuel.

The following are specific examples of implementation of the proposed method.

Example 1.

Hydrogenation refining the distillate is subjected to West-Siberian oil with 1 wt.% sulfur, wikipedi in the temperature range 190-355°C. the Specified raw materials after mixing with hydrogen-rich recycle gas pre-flow through "filter" layer, which is a layer of ceramic balls with a diameter of 6 mm, occupying 0.2% re is clonage volume, and a layer of catalyst Hydrotreating representing the contact, containing 2 wt.% molybdenum oxide on alumina and occupying 10% of the reaction volume. Then the raw material goes through a layer of a hydrogenation catalyst containing 2 wt.% oxide of cobalt, 14 wt.% molybdenum oxide, the rest is aluminum oxide.

Process for hydrogenation refining is carried out at a pressure of 4 MPa, a temperature of 400°C, flow rate of feed of 0.5 h^-1, the ratio of hydrogen gas/raw material 400.about.

The result is a diesel fuel containing less than 0.005 wt.% sulfur and less than 11 wt.% polycyclic aromatic hydrocarbons, which corresponds to the modern requirements for diesel fuel.

Example 2.

Hydrogenation refining the distillate is subjected to sulfur Eastern oil content of 1.4 wt.% sulfur, wikipedi in the temperature range 180-350°C. the Specified raw materials after mixing with hydrogen-rich recycle gas pre-flow through "filter" layer, which is a layer of ceramic balls with a diameter of 20 mm, occupying 5% of the reaction volume, and a layer of catalyst Hydrotreating representing the contact, containing 10 wt.% molybdenum oxide on alumina and occupies 0.5% of the reaction volume. Then the raw material goes through a layer of a hydrogenation catalyst containing 3 the AC.% Nickel oxide, 15 wt.% molybdenum oxide, the rest is aluminum oxide.

Process for hydrogenation refining is carried out at a pressure of 7 MPa, a temperature of 370°C, space velocity of the raw material 1 hour^-1the ratio of hydrogen gas/raw material 600.about.

The result is a diesel fuel containing less than 0.001 wt.% sulfur and less than 11 wt.% polycyclic aromatic hydrocarbons, which corresponds to the modern requirements for diesel fuel.

Example 3.

Hydrogenation beautification is subjected to a mixture of distillate West Siberian oil and light gas oil catalytic cracking with the content of 1.6 wt.% sulfur. Specified raw materials after mixing with hydrogen-rich recycle gas pre-flow through "filter" layer, which is a layer of ceramic balls with a diameter of 12 mm, occupying 2% of the reaction volume, and a layer of catalyst Hydrotreating representing the contact, containing 5 wt.% molybdenum oxide on alumina and occupying 5% of the reaction volume. Then the raw material goes through a layer of a hydrogenation catalyst containing 4 wt.% Nickel oxide, 20 wt.% molybdenum oxide, the rest is aluminum oxide.

Process for hydrogenation refining is carried out at a pressure of 10 MPa, a temperature of 340°C, space velocity of the raw materials 3 h^-1the ratio vodorazdelnaya/raw 1200 rpm./about.

The result is a diesel fuel containing less than 0.005 wt.% sulfur and less than 11 wt.% polycyclic aromatic hydrocarbons, which corresponds to the modern requirements for diesel fuel.

Example 4.

Carried out under the conditions of example 2 except that the hydrogenation catalyst, which is used as two sequentially loaded catalyst: AKM (20% loading) and AMN (80% load).

The result is a diesel fuel containing less than 0.005 wt.% sulfur and less than 11 wt.% polycyclic aromatic hydrocarbons, which corresponds to the modern requirements for diesel fuel.

1. Method for hydrogenation refining of diesel distillates, including stage Hydrotreating and hydrogenation of the raw material is carried out at elevated temperature and pressure in the presence of a catalyst, characterized in that the pre-raw materials pass through a "filter" layer, which is a layer of ceramic balls, occupying 0,2-5,0% of the reaction volume, at the stage Hydrotreating using a catalyst comprising a contact layer containing 2-10 wt.% molybdenum oxide on alumina and occupying 0.5 to 10% of the reaction volume, and at the stage hydrogenation using aluminumalloy and/or allocability catalyst.

2. The method according to claim 1, characterized those who, the process is carried out at a pressure of 4-10 MPa, a temperature of 340-400°C, flow rate of feed of 0.5 to 3.0 HR^-1, the ratio of the hydrogen-containing gas:raw=400-1200 rpm./about.