CN109694732A

CN109694732A - The method for processing heavy diesel

Info

Publication number: CN109694732A
Application number: CN201710994513.2A
Authority: CN
Inventors: 赵广乐; 孟勇新; 李明丰; 任亮; 赵阳; 杨平; 胡志海
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2017-10-23
Filing date: 2017-10-23
Publication date: 2019-04-30
Anticipated expiration: 2037-10-23
Also published as: CN109694732B

Abstract

The present invention relates to refining art, heavy diesel raw material is introduced in hydrofining reactor this method comprises: (1) is in presence of hydrogen and carries out the first haptoreaction by the method for disclosing processing heavy diesel；(2) liquid efflunent in the hydrofining reactor is introduced in separation fractionating system and is separated and be fractionated respectively obtains light hydrogenated diesel oil and weight hydrogenated diesel oil；(3) the part heavy hydrogenated diesel oil is recycled to finishing reactor entrance to carry out first haptoreaction together with the heavy diesel raw material；At least partly described light hydrogenated diesel oil is introduced in hydrocracking reactor simultaneously and carries out the second haptoreaction；(4) liquid efflunent in the hydrocracking reactor is separated and is fractionated to obtain hydro-upgrading diesel oil.Method of the invention can obtain high octane gasoline component and/or BTX industrial chemicals, also, method of the invention has the advantages that the device cycle of operation long.

Description

The method for processing heavy diesel

Technical field

The present invention relates to refining arts, and in particular to a method of processing heavy diesel.

Background technique

With the aggravation of crude oil heaviness, in poor quality process, the quality of catalytic cracking diesel oil is increasingly worse, throughput requirements by Year increases, this partially catalyzed cracked diesel oil accounts for about the one third of Chinese commodity diesel oil share.

Currently, the processing energy of catalytic cracking unit is continuously improved for more light-end products that abstract from crude oil in refinery Power and working depth cause the quality of catalytic cracking diesel oil to be further deteriorated, this is mainly shown as high arene content, sulphur and nitrogen etc. Impurity content is high, and Cetane number is low.At the same time, with increasingly stringent, the state V derv fuel standard requirements 16 of environmental protection legislation Alkane value is not less than 51, and sulfur content is not more than 10 μ g/g, and arene content is not higher than 11%, and requirement will be increasingly stringenter.It is another Aspect, catalytic gasoline proportion is up to 78 weight % in China's gasoline pool at present, causes the alkene of gasoline and sulfur content high, fragrant Hydrocarbon content is low, octane number is relatively relatively low.

Further, since diesel oil consumes stagflation, the factory of Some Enterprises diesel oil is difficult, reduces diesel and gasoline ratio and largely refines as China The trend of factory.

Therefore, heavy inferior diesel oil manufacturing process is enriched, the yield of premium-type gasoline product is improved, is that enterprise is promoted to increase High added value oil product yield, adjustment structure, the effective measures of Improve Efficiency.

The technique of heavy inferior diesel production high added value oil product mainly has hydrofinishing and is hydrocracked two classes.

However, handle catalytic diesel oil using conventional hydrofining technology, although can be effectively removed the sulphur in diesel oil, The impurity such as nitrogen, but diesel product Cetane number increase rate is limited, and diesel oil density variation is also little；It is hydrocracked using traditional Technique processes poor ignition quality fuel, although the diesel product of gasoline products and high-quality can be produced, naphtha cut octane number It is lower, and device lifetime suffers from the influence of heavy inferior raw material, and cycle of oparation is generally only at 1 year or so.

US7384542B1 discloses a kind of method for producing low-sulfur diesel-oil and high-knock rating gasoline.The prior art will be straight It evaporates diesel oil and/or light wax tailings (LCGO) introduces hydrodesulfurization, hydrodenitrogeneration reaction zone, catalytic cracking diesel oil (LCO) enters Hydrocracking reaction area enters cold high score, low point cold after the product mixing of two reaction zones, separates subsequently into fractionating system To antiknock component and low-sulfur diesel-oil.Hydrocracking reaction area uses amorphous or sieves water containing low molecule in the prior art Flat hydrocracking catalyst.The prior art can process straight-run diesel oil and/or LCGO and part boiling range is 149~343 DEG C LCO, the octane number for the heavy naphtha fraction that obtained boiling range is 88~193 DEG C is that the sulphur of 87, > 193 DEG C of diesel oil distillates contains Amount is less than 10ppm, Cetane lndex 46.

CN102311795A discloses a kind of method of hydrotreating by diesel raw material production high octane gasoline component.This is existing The raw material boiling spread of technology is 165~400 DEG C, and first segment diesel raw material falls part by appropriateness plus hydrogen, products therefrom removing After hydrogen sulfide and ammonia, liquid stream fully enters second segment and carries out hydrocracking reaction, obtains high-knock rating gasoline fraction and clear Cleaning diesel oil blend component.

CN105618111A discloses the preparation method and hydrogenation technique of a kind of catalytic diesel oil hydrogenation conversion catalyst, this is urged Agent is combined into metal component with bimetallic group, and uses the maceration extract of active metal to impregnate Y molecular sieve first to improve active gold Belong to effective rate of utilization and control the whole hydrogenation capability of catalyst, and then improves the hydrogenation reaction selectivity of catalyst and stablize Property.

It needs for catalytic diesel oil to be cut into light catalysis in advance before can be seen that processing catalytic diesel oil raw material from the above prior art Diesel oil and weight catalytic diesel oil, processing raw material to do is restricted, and when higher catalytic diesel oil raw material is done in processing without alleviation The means that polycyclic aromatic hydrocarbon carbon deposit influences catalyst life, device are difficult to ensure operation cycle.Using rich in aromatic hydrocarbons diesel oil as Raw material production BTX or high octane gasoline component technology difficult point be how holding while obtaining high polycyclic aromatic hydrocarbon conversion ratio Higher mononuclear aromatics or BTX selectivity.

Summary of the invention

The object of the present invention is to provide one kind to produce high octane gasoline component and/or BTX chemical industry by heavy diesel raw material The method of hydrotreating of raw material, specifically, the invention aims to solve prior art processing heavy inferior diesel production Gaoxin When alkane value gasoline component and/or BTX industrial chemicals, existing product octane number is low or mononuclear aromatics content is low and device is transported Row period short problem.

To achieve the goals above, the present invention provides a kind of method for processing heavy diesel, this method comprises:

(1) in presence of hydrogen, heavy diesel raw material is introduced in hydrofining reactor and wherein contain plus hydrogen Catalyst for refining carries out the first haptoreaction；

(2) liquid efflunent in the hydrofining reactor is introduced in separation fractionating system and is separated With fractionation to respectively obtain light hydrogenated diesel oil and weight hydrogenated diesel oil, the cut point of the light hydrogenated diesel oil and the heavy hydrogenated diesel oil It is 280~350 DEG C；

(3) by the part heavy hydrogenated diesel oil be recycled to raw material surge tank or the finishing reactor entrance with it is described heavy Matter diesel raw material carries out first haptoreaction together, and weight hydrogenated diesel oil described in remainder is gone out device；Simultaneously will At least partly described light hydrogenated diesel oil, which is introduced in hydrocracking reactor, carries out the with the hydrocracking catalyst that wherein contains Two haptoreactions；

(4) liquid efflunent in the hydrocracking reactor is introduced in separation fractionating system and is separated With fractionation to obtain hydro-upgrading diesel oil,

Wherein, the boiling point of the heavy diesel raw material is 165~450 DEG C.

The method of processing heavy diesel provided by the invention, it is not necessary that catalytic diesel oil (heavy diesel raw material) is fractionated in advance, After the hydrogenated purification of diesel raw material, weight hydrogenated diesel oil part is recycled back to hydrofining reaction area, improves Cetane number and hydro carbons group At product can be used as diesel oil blending component or fcc raw material；Light hydrogenated diesel oil rich in aromatic hydrocarbons enters hydrocracking reaction area and follows Ring conversion, the hydrocracking catalyst have the characteristics that arene content is high in yield of gasoline height and product naphtha cut, can spirit Volume increase high-knock rating gasoline blend component or BTX raw material living.

Under preferable case, two-stage process process of the invention can share separation, fractionating system, and process is simple, Neng Goutuo Wide diesel raw material range extends device operation cycle and increases production high value added product.

Specifically, method of the invention can obtain high octane gasoline component and/or BTX industrial chemicals, also, this hair Bright method has the advantages that the device cycle of operation long.

Detailed description of the invention

Fig. 1 is a kind of process flow of preferred embodiment of the method for processing heavy diesel of the invention.

Description of symbols

1, heavy diesel raw material 2, hydrofining reactor

3, the first liquid efflunent 4, cold high score

5, third liquid stream 6, the first sour water

7, low point of the 8, the 4th liquid stream

9, the second sour water 10, second gas

11, fractionating column 12, light naphtha fraction

13, heavy naphtha fraction 14, remaining light hydrogenated diesel oil

15, weight hydrogenated diesel oil 16, hydro-upgrading diesel oil

17, hydrocracking reactor 18, first gas

19, second effluent 20, circulating hydrogen compressor

21, new hydrogen 22, first circulation hydrogen

23, second circulation hydrogen

Specific embodiment

The endpoint of disclosed range and any value are not limited to the accurate range or value herein, these ranges or Value should be understood as comprising the value close to these ranges or value.For numberical range, between the endpoint value of each range, respectively It can be combined with each other between the endpoint value of a range and individual point value, and individually between point value and obtain one or more New numberical range, these numberical ranges should be considered as specific open herein.

As previously mentioned, the present invention provides a kind of methods for processing heavy diesel, this method comprises:

Wherein, the boiling point of the heavy diesel raw material is 165~450 DEG C.

Two kinds of preferred embodiments of the method for aforementioned processing heavy diesel of the invention presented below:

The first: preferably in step (3), the part light hydrogenated diesel oil being introduced in hydrocracking reactor and it In the hydrocracking catalyst that contains carry out the second haptoreaction, light hydrogenated diesel oil described in remainder is as the hydro-upgrading Diesel oil goes out device, and the liquid efflunent in the hydrocracking reactor in step (4) is introduced in step (2), Fractionation train is separated to be concomitantly introduced into the liquid efflunent in the hydrofining reactor in step (2) to same It is separated and is fractionated in system.

In the first described preferred embodiment, it is introduced to light in the hydrocracking reactor plus hydrogen bavin Oil is 20~50 weight % of the heavy diesel raw material in step (1).

Second: preferably in step (3), all light hydrogenated diesel oils being introduced in hydrocracking reactor and it In the hydrocracking catalyst that contains carry out in the hydrocracking reactor in the second haptoreaction and step (4) Liquid efflunent is from the liquid efflunent in the hydrofining reactor in step (2) respectively in different separation point It evaporates and is separated and be fractionated in system.

The present invention more preferably carries out the processing heavy of the invention using the first aforementioned preferred embodiment The method of diesel oil.

In the method for the invention, in the hydrofining reactor, the heavy diesel raw material is substantially carried out plus hydrogen The reactions such as desulfurization, hydrodenitrogeneration and aromatic hydrocarbons saturation.In the present invention, hydrofining reactor effluent is separated, is fractionated to obtain weight Hydrogenated diesel oil and light hydrogenated diesel oil, wherein light hydrogenated diesel oil has higher mononuclear aromatics content, nitrogen compared with weight hydrogenated diesel oil Content is lower, polycyclic aromatic hydrocarbon content is lower, is more suitable for producing antiknock component as the charging for being hydrocracked section, and adds again Hydrogen diesel oil can be effectively improved its aromatic hydrocarbons by freshening to hydrofining reactor and constitute, and promote polycyclic aromatic hydrocarbon supersaturation, and The high cetane value constituents such as the long chain alkane in diesel oil distillate section, the cycloalkane with long side chain or alkylbenzene can be retained, reached The purpose for improving diesel product Cetane number, improving diesel product quality.

In the method for the invention, in the hydrocracking reactor, the low nitrogen rich in mononuclear aromatics structure gently adds hydrogen Diesel oil carries out the reaction such as selective opening, cracking preferably on adding hydrogen-cracking function catalyst.The cycloalkyl-monocyclics such as naphthane The reaction such as selective opening, cracking occurs for aromatic hydrocarbons；Side chain cleavage reaction occurs for the mononuclear aromatics with side chain such as alkylbenzene, to reach Into diesel oil distillate, mononuclear aromatics is converted into the antiknock components such as the benzene,toluene,xylene in naphtha cut, and improves Naphtha cut yield improves naphtha cut product hydro carbons composition, improves gasoline fraction product octane number purpose.And containing polycyclic Aromatic hydrocarbons and the relatively large number of part weight hydrogenated diesel oil of condensed-nuclei aromatics are then fractionated tower before entering hydrocracking reactor and go out device, The deactivation rate of catalyst in hydrocracking reactor can be significantly reduced, device operation cycle is extended.This part diesel oil due to Molecular weight is relatively large, is more prone to generate gasoline fraction in catalytic cracking conversion, can reduce the yield of liquefied gas, dry gas.

Preferably, total arene content in the heavy diesel raw material is 60 weight % or more, and the bicyclic above aromatic hydrocarbons Content is 40 weight % or more.It is highly preferred that the content of the bicyclic above aromatic hydrocarbons in the heavy diesel raw material is 45 weight % More than.

Under preferable case, the heavy diesel raw material is selected from catalytic cracking light cycle oil, heavy catalytic cycle oil, cycloalkanes At least one of the coker gas oil of base oil, the diesel oil distillate of coal direct liquefaction oil, diesel oil distillate of coal tar.

Preferably, in step (3), it is recycled to the described heavy plus hydrogen bavin of raw material surge tank or the finishing reactor entrance Oil is 5~60 weight %, more preferably 10~40 weight % of the heavy diesel raw material in step (1).

In the present invention, preferably weight hydrogenated diesel oil described in device part as diesel oil blending component or enters catalytic cracking dress out It sets.

According to a kind of preferred embodiment, controls the first catalytic condition and step (2) are obtained The heavy hydrogenated diesel oil in mononuclear aromatics content be 50 weight % or more, nitrogen content is less than 50 μ g/g.More according to another kind Preferred embodiment controls the heavy hydrogenated diesel oil that the first catalytic condition obtains step (2) The content of middle mononuclear aromatics is 60 weight % or more, and more preferable 65 weight % or more, nitrogen content is less than 30 μ g/g.

It was found by the inventors of the present invention that the control first catalytic condition makes the described heavy of step (2) acquisition The property of hydrogenated diesel oil it is of the invention it is aforementioned preferably with preferred specific embodiment within the scope of when, be conducive to voluminous Gaoxin Alkane value gasoline component and/or BTX industrial chemicals, and can guarantee the long-period stable operation of hydrocracking catalyst.

Under preferable case, the first catalytic condition includes: that hydrogen partial pressure is 3.0~13.0MPa, more preferably 4.0~9.0MPa；Reaction temperature is 300~450 DEG C, more preferably 330~410 DEG C；Hydrogen to oil volume ratio is 400~2000Nm³/ m³, more preferably 500~1500Nm³/m³；In terms of fresh material (the heavy diesel raw material as in step (1)), volume is empty when liquid Speed is 0.2~5.0h^-1, more preferably 0.5~3.0h^-1。

Under preferable case, the second catalytic condition includes: that hydrogen partial pressure is 3.0~13.0MPa, more preferably 4.0~9.0MPa；Reaction temperature is 300~450 DEG C, more preferably 330~440 DEG C；Hydrogen to oil volume ratio is 400~2000Nm³/ m³, more preferably 500~1500Nm³/m³；In terms of fresh material (the heavy diesel raw material as in step (1)), volume is empty when liquid Speed is 0.4~8.0h^-1, more preferably 0.7~4.0h^-1。

Hydrobon catalyst and hydrocracking catalyst grading composition are used in the present invention, preferably according to heavy diesel original Expect the filling ratio of arene content and nitrogen content adjustment Hydrobon catalyst and hydrocracking catalyst.Under preferable case, institute State the dress of the Hydrobon catalyst in hydrofining reactor and the hydrocracking catalyst in the hydrocracking reactor Filling out volume ratio is (0.2~5): 1, more preferably (0.5~2): 1.In usual heavy diesel raw material containing higher unsaturated hydrocarbons, Carbon residue or tenor, major catalyst carbon deposit is too fast and bed pressure drop reaches limit value too quickly to prevent, can be in hydrofinishing Filling accounts for 5~30% hydrogenation protecting agent of Hydrobon catalyst volume total amount respectively at the top of catalyst bed, wherein taking off residual Charcoal protective agent and demetalization protective agent admission space account for the 1~20% of Hydrobon catalyst volume total amount, deolefination protective agent Admission space accounts for the 1~20% of Hydrobon catalyst volume total amount.

Nickel oxide containing 1.0~5.0 weight %, 5.5~10.0 weight % in the preferably described hydrogenation protecting agent of the present invention Molybdenum oxide and with diplopore distribution gamma-aluminium oxide carrier.

It under preferable case, is counted by oxide and on the basis of the Hydrobon catalyst, the Hydrobon catalyst In be 1~10 weight % containing carrier and load content on the carrier VIII group non-noble metal j element and/or content For the group vib non-noble metal j element of 10~45 weight %.That is, when non-containing VIII group in the Hydrobon catalyst When precious metal element, preferably the content of VIII group non-noble metal j element is 1~10 weight %；When in the Hydrobon catalyst When containing group vib non-noble metal j element, preferably the content of group vib non-noble metal j element is 10~45 weight %；If containing simultaneously VIII group non-noble metal j element and group vib non-noble metal j element, then the content of VIII group non-noble metal j element is 1~10 weight The content for measuring % and the group vib non-noble metal j element is 10~45 weight %.

Preferably, in the Hydrobon catalyst, the VIII group non-noble metal j element be cobalt and/or nickel, it is described Group vib non-noble metal j element is molybdenum and/or tungsten.

Preferably, in the Hydrobon catalyst, the carrier is aluminium oxide and/or silica.

Under preferable case, containing carrier and as the metallic element tungsten of active component, institute in the hydrocracking catalyst Stating carrier is the mixture containing solid acid component and heat-resistant inorganic oxide, and the solid acid component is silica-alumina And/or y-type zeolite, the heat-resistant inorganic oxide are at least one of aluminium oxide, silica and aluminium oxide-silicon oxide.

Preferably, in the hydrocracking catalyst, on the basis of carrier therein, the content of the solid acid component For 0.5~95 weight %, the content of the heat-resistant inorganic oxide is 5~99.5 weight %；It is highly preferred that being split in described plus hydrogen Change in catalyst, on the basis of carrier therein, the content of the solid acid component is 1~80 weight %, the heat resistant inorganic The content of oxide is 20~99 weight %.

It under preferable case, is counted by oxide and on the basis of the hydrocracking catalyst, the hydrocracking catalyst The content of middle tungsten is 1~50 weight %, more preferably 5~40 weight %, further preferably 8~30 weight %.

According to a kind of preferred embodiment, the solid acid component be y-type zeolite, the y-type zeolite be selected from HY, Rare Earth Y, rare earth HY zeolite, super steady Y, hyperastable Y-type RE zeolite, the Y zeolite of part amorphous, the Y zeolite of titaniferous, phosphorous Y At least one of.

In the present invention, it is preferred to which the y-type zeolite is WY type zeolite, the content of W is in terms of oxide in the WY type zeolite The metallic element tungsten in the hydrocracking catalyst as active component is accounted for WO₃3~80 weight % of the dosage of meter, it is more excellent Select 5~40 weight %.

Preferably, the WY type zeolite is that W is introduced into y-type zeolite and is formed using solid state ion exchange method.

The y-type zeolite provided by the invention, the especially described WY type zeolite, has the function of excellent selective cracking, Moderate Hydrogenation has good selection to reactions such as the fracture of mononuclear aromatics side chain, naphthane selective opening and disconnected side chains Property, making to modify the mononuclear aromatics in diesel oil distillate occurs the high octane gasoline components such as selective cracking reaction generation benzene, toluene, It can avoid antiknock component supersaturation simultaneously, reaching improves naphtha cut hydro carbons composition, increases octane number, improves BTX The purpose of raw material arene content.

It is pungent that aforementioned hydrogenation catalyst for refining and hydrocracking catalyst provided by the invention improve conventional catalyst production Mononuclear aromatics selectivity in alkane value gasoline component or BTX technical products, so that the naphtha product obtained has high octane number Or mononuclear aromatics content, performance are obviously improved.

A kind of preferred embodiment of the method for processing heavy diesel of the invention is provided below in conjunction with Fig. 1:

Heavy diesel raw material 1 is mixed with first circulation hydrogen 22, subsequently into hydrofining reactor 2, heavy diesel raw material 1 Desulfurization, denitrogenation and part aromatic hydrocarbons saturated reaction preferably occurs under the action of Hydrobon catalyst with recycle hydrogen 22, comes from The first liquid efflunent 3 in the hydrofining reactor 2 and the second effluent 19 1 from hydrocracking reactor 17 It rises to enter in cold high score 4 and carries out Oil-gas Separation.The first gas 18 at cold 4 top of high score enters in circulating hydrogen compressor 20, circulation After the exit gas of hydrogen compressor 20 is mixed with new hydrogen 21, it is recycled to and adds respectively as first circulation hydrogen 22 and second circulation hydrogen 23 The entrance of hydrogen finishing reactor 2 and hydrocracking reactor 17；The bottom of cold high score 4 obtains the first sour water 6；And cold height The third liquid stream 5 for dividing 4 lower parts to isolate, which enters in low point 7, carries out further Oil-gas Separation, what low point 7 top was isolated The second sour water 9 that second gas 10 and bottom are isolated goes out device, and the 4th liquid stream 8 isolated enters fractionating column 11.12 ejector of light naphtha fraction that 11 tower top of fractionating column is isolated, and by 13 withdrawing device of heavy naphtha fraction；It obtains Light hydrogenated diesel oil in part as hydro-upgrading diesel oil 16 go out device, be fractionated tower 11 fractionation also obtain gasoline fraction (not shown), the remainder in the light hydrogenated diesel oil obtained by fractionating column 11 is as remaining light hydrogenated diesel oil 14 and recycle hydrogen one It rises and enters hydrocracking reactor 17, hydrocracking reaction occurs in hydrocracking reactor 17, is obtained after hydrocracking reaction The second effluent obtained is introduced in cold high score 4 by pipeline to be separated.In the weight hydrogenated diesel oil 15 obtained by fractionating column 11 A part goes out device, and remainder freshening is into hydrofining reactor 2.

The method of processing heavy diesel provided by the invention also has the advantages that following specific:

(1) present invention uses two sections of part circulation process, shares separation fractionating system.Hydrofining reaction area effluent is first The relatively large number of heavy hydrogenated diesel oil of first that molecular weight is larger, polycyclic and condensed-nuclei aromatics content separates, boiling range is relatively light, be rich in monocycle The light hydrogenated diesel oil of aromatic hydrocarbons enters hydrocracking reaction area, and conversion and cycle is antiknock component.

Since weight hydrogenated diesel oil does not enter hydrocracking reaction area, the heavy diesel that height is done is can be processed in the present invention Raw material avoids hydrocracking catalyst due to the coke precursors such as relatively large number of polycyclic and condensed-nuclei aromatics in heavier boiling range diesel oil Carbon deposit increases catalyst deactivation rate, the shortening of the caused cycle of operation.

The present invention has effectively widened the boiling range range of device raw material, is not needing individual fractionating device to heavy diesel original Under the premise of expecting prefractionation, the processing to wide boiling range range diesel raw material is realized.

Briefly, the heavy constituent in heavy diesel raw material is carried out in process flow of the invention adds hydrogen-decarburization route, gently Component is carried out entirely plus the purpose of diesel oil distillate producing high-octane gasoline component is realized in hydrogen route, two lines complementation.

2) weight hydrogenated diesel oil part is recycled back to hydrofining reaction area, its polycyclic aromatic hydrocarbon can be promoted further to add hydrogen full With improve Cetane number and hydro carbons and constitute, also the mononuclear aromatics in fresh feed can be inhibited to be saturated to a certain extent, played Retain the effect of mononuclear aromatics.

The molecule of weight hydrogenated diesel oil is relatively large, mononuclear aromatics content is high, and the low feature of sulphur, nitrogen content is suitble in catalytic cracking Unit is converted into high-knock rating gasoline fraction, and reduces the yield of dry gas, liquefied gas.

Light hydrogenated diesel oil molecule is small, mononuclear aromatics content is high, increases production the excellent of high octane gasoline component and BTX industrial chemicals Matter raw material.And since fraction is relatively light, polycyclic and condensed-nuclei aromatics content is low, has on hydrocracking catalyst lower Coke forming property can effectively extend device operation cycle.

Light hydrogenated diesel oil fraction in hydrocracking reaction area conversion and cycle, can according to the yield of naphtha cut or it is light plus The internal circulating load for being hydrocracked severity and light hydrogenated diesel oil is adjusted flexibly in the quality of hydrogen modification diesel product.

It below will the present invention will be described in detail by example.

In following instance, the trade names of Hydrobon catalyst A are RS-1000, the commodity board of hydrocracking catalyst B Number be RHC-5, by Sinopec Group's catalyst Chang Ling branch company produce.

The preparation process of hydrocracking catalyst C is as follows:

Taking butt is 100.0 grams of the USY type zeolite (catalyst Chang Ling branch company, 24.43 angstroms of lattice constant) of 85 weight % It grinds, be uniformly mixed in mortar with 5.9 grams of tungsten oxides；It is subsequently placed in tube furnace flat-temperature zone, under hydrogen and steam atmosphere (hydrogen: vapor volume ratio=30:1) is handled 4 hours in 450 DEG C, obtains the modified USY type molecule of W of solid phase exchange process preparation Sieve WUSY2.

Weigh 128.6 grams of the boehmite (catalyst Chang Ling branch company) and WUSY2 (132.4 that butt is 70 weight % Gram) be uniformly mixed, it is 1.6 millimeters of three leaf bar shapeds that circumscribed circle diameter is extruded on banded extruder, dry 3 hours in 120 DEG C, 600 DEG C roasting obtains catalyst carrier Z in 4 hours.

100g carrier Z is taken, contains WO respectively with 83 milliliters₃(174.2 grams per liter), P₂O₅The ammonium metatungstate of (29.0 grams per liter) and Phosphoric acid mixed solution impregnates 1 hour, dries in 120 DEG C 2 hours, and 450 DEG C roast 3 hours, obtain catalyst C.

For the Hydrogenation for giving full play to catalyst, above-mentioned catalyst carries out at presulfurization before formally contact raw material Reason.In comparative example and embodiment set forth below, the method for pre-sulphuration of each catalyst is identical.

Feedstock oil D used in embodiment and feedstock oil E is catalytic cracking diesel oil, and property is listed in table 1.

Embodiment 1

Feedstock oil D is handled using technique shown in Fig. 1.

Feedstock oil D finishing reactor hydrogenated first is contacted with Hydrobon catalyst A, boiling point adding again higher than 320 DEG C Freshening is to hydrofining reactor after hydrogen diesel oil distillate is mixed with hydrogen, and wherein mononuclear aromatics content is 66 weight %, recycle ratio Example accounts for the 20 weight % of feedstock oil D.Light hydrogenated diesel oil fraction of a part of boiling point less than 320 DEG C enters after mixing with recycle hydrogen and adds Hydrogen cracker is contacted with hydrocracking catalyst C, and circulation ratio accounts for the 35 weight % of feedstock oil D, hydrocracking reactor Effluent is separated, is fractionated to obtain light naphthar, gasoline fraction and hydro-upgrading diesel oil.Specific reaction condition is as shown in table 2, Product yield and property are as shown in table 3.

Comparative example 1

Feedstock oil D is handled using single hop serial flow.

Specifically, feedstock oil D mixed with hydrogen successively in hydrofining reactor Hydrobon catalyst A and add hydrogen Hydrocracking catalyst C contact in cracker, products therefrom separated, be fractionated to obtain light naphthar, gasoline fraction, light Hydrogenated diesel oil fraction and weight hydrogenated diesel oil fraction.Specific reaction condition is as shown in table 2, and product yield and property are as shown in table 3. As can be seen from Table 2, heavy diesel raw material all enters in hydrocracking reactor after hydrogenated purification, hydrocracking catalyst The deactivation rate of agent significantly improves.

Embodiment 2

Feedstock oil E is handled using technique shown in Fig. 1.

Feedstock oil E finishing reactor hydrogenated first is contacted with Hydrobon catalyst A, boiling point adding again higher than 330 DEG C For freshening to hydrofining reactor, freshening ratio accounts for the 15 weight % of feedstock oil E after hydrogen diesel oil distillate is mixed with hydrogen.A part Light hydrogenated diesel oil fraction of the boiling point less than 330 DEG C enters hydrocracking reactor and hydrocracking catalyst after mixing with recycle hydrogen C contact, circulation ratio account for the 25 weight % of feedstock oil E, and hydrocracking reactor effluent is separated, is fractionated to obtain pumice brain Oil, gasoline fraction and hydro-upgrading diesel oil.Specific reaction condition is as shown in table 2, and product yield and property are as shown in table 3.

Embodiment 3

Feedstock oil E is handled using technique shown in Fig. 1.

Feedstock oil E finishing reactor hydrogenated first is contacted with Hydrobon catalyst A, boiling point adding again higher than 330 DEG C For freshening to hydrofining reactor, freshening ratio accounts for the 15 weight % of feedstock oil E after hydrogen diesel oil distillate is mixed with hydrogen.A part Light hydrogenated diesel oil fraction of the boiling point less than 330 DEG C enters hydrocracking reactor and hydrocracking catalyst after mixing with recycle hydrogen B contact, circulation ratio account for the 25 weight % of feedstock oil E, and hydrocracking reactor effluent is separated, is fractionated to obtain pumice brain Oil, gasoline fraction and hydro-upgrading diesel oil.Specific reaction condition is as shown in table 2, and product yield and property are as shown in table 3.

Table 1

Feedstock oil	D	E
			Density (20 DEG C)/(g/cm³)	0.9484	0.9625
Sulfur content/(μ g/g)	3800	6200
			Nitrogen content/(μ g/g)	950	500
Cetane number	16.5	18.3
			Total aromatic hydrocarbons/%	77.9	88.6
The bicyclic above arene content/weight %	51.6	72.4
			Boiling range (ASTM D-86)/DEG C
Initial boiling point	194	186
			50%	303	282
The end point of distillation	405	385

Table 2

	Embodiment 1	Comparative example 1	Embodiment 2	Embodiment 3
					Feedstock oil	D	D	E	E
Hydrotreating/hydrocracking catalyst	A/C	A/C	A/C	A/B
					Catalyst packing volume ratio	60:40	60:40	55:45	55:45
Weight hydrogenated diesel oil cut point/DEG C	320	/	330	330
					Hydrofining reaction area:
Hydrogen partial pressure, MPa	7.0	7.0	6.0	6.0
					Reaction temperature, DEG C	370	370	380	380
Volume space velocity, h^-1	2.0	2.0	2.5	2.5
					Hydrogen to oil volume ratio, Nm³/m³	800	800	1000	1000
Hydrocracking reaction area:
					Hydrocracking catalyst deactivation rate/(DEG C/day)	0.07	0.12	0.07	0.07
Hydrogen partial pressure, MPa	7.0	7.0	7.5	7.5
					Reaction temperature, DEG C	390	400	395	395
Volume space velocity, h^-1	3.0	3.0	2.0	2.0
					Hydrogen to oil volume ratio, Nm³/m³	1100	1100	1200	1200

Table 3

Hydrocracking catalyst can be significantly reduced using the method for the present invention it can be seen from catalyst deactivation rate in table 2 The deactivation rate of agent；As can be seen from Table 3, high using gasoline fraction octane number obtained by the method for the present invention, and weight hydrogenated diesel oil evaporates Mononuclear aromatics content is high in point.

The result of comparative example 2 and embodiment 3 can be seen that the preferred class of catalyst that method of the invention provides The quality for the sulfur product for enabling to method of the invention to obtain significantly improves.

The preferred embodiment of the present invention has been described above in detail, and still, the present invention is not limited thereto.In skill of the invention In art conception range, can with various simple variants of the technical solution of the present invention are made, including each technical characteristic with it is any its Its suitable method is combined, and it should also be regarded as the disclosure of the present invention for these simple variants and combination, is belonged to Protection scope of the present invention.

Claims

1. A method for processing heavy diesel oil, the method comprising:

(1) in the presence of hydrogen, the heavy diesel raw material is introduced into the hydrotreating reactor to carry out the first contact reaction with the hydrotreating catalyst contained therein;

(2) introducing the liquid effluent from the hydrotreating reactor into a separation fractionation system for separation and fractionation to obtain light hydrogenated diesel oil and heavy hydrogenated diesel oil, respectively, the light hydrogenated diesel oil and the heavy hydrogenated diesel oil The fractionation point of hydrogenated diesel oil is 280～350℃;

(3) recycle a part of the heavy hydrogenated diesel oil to the feedstock buffer tank or the inlet of the refining reactor to carry out the first contacting reaction with the heavy diesel feedstock, and the remaining part of the heavy hydrogenated diesel oil At the same time, at least part of the light hydrogenated diesel oil is introduced into the hydrocracking reactor to carry out a second contact reaction with the hydrocracking catalyst contained therein;

(4) introducing the liquid effluent from the hydrocracking reactor into a separation and fractionation system for separation and fractionation to obtain hydro-upgraded diesel oil,

Wherein, the boiling point of the heavy diesel raw material is 165-450°C.

2. The method according to claim 1, wherein, in step (3), a part of the light hydrogenated diesel oil is introduced into a hydrocracking reactor to carry out a second contact reaction with the hydrocracking catalyst contained therein, The remaining part of the light hydrogenated diesel oil is taken out of the device as the hydro-upgraded diesel oil, and the liquid effluent in the hydrocracking reactor in step (4) is introduced into step (2) to be combined with step (4). The liquid effluent from the hydrofinishing reactor in (2) is introduced together into the same separation and fractionation system for separation and fractionation.

3. The method of claim 2, wherein the light hydrogenated diesel oil introduced into the hydrocracking reactor is 20-50 wt% of the heavy diesel feedstock in step (1).

4. The method according to claim 1, wherein, in step (3), all of the light hydrogenated diesel oil is introduced into the hydrocracking reactor to carry out a second contact reaction with the hydrocracking catalyst contained therein, And the liquid effluent in the described hydrocracking reactor in the step (4) and the liquid effluent in the step (2) from the hydrorefining reactor are separated and separated in separate fractionation systems. Fractionation.

5. The method according to any one of claims 1-4, wherein the total aromatics content in the heavy diesel feedstock is more than 60% by weight, and the content of aromatics above the bicyclic ring is more than 40% by weight; preferably ,

The content of aromatic hydrocarbons above bicyclic in the heavy diesel raw material is 45% by weight or more.

6. The method according to any one of claims 1-5, wherein the heavy diesel feedstock is selected from the group consisting of catalytic cracking light cycle oil, catalytic cracking heavy cycle oil, coker diesel oil of naphthenic crude oil, direct coal liquefaction At least one of the diesel fraction of oil and the diesel fraction of coal tar.

7. The method according to any one of claims 1-4, wherein, in step (3), the heavy hydrogenated diesel oil circulated to the raw material buffer tank or the inlet of the refining reactor is step (1) 5 to 60 wt % of the heavy diesel raw material in the medium, preferably 10 to 40 wt %.

8. The method according to any one of claims 1-4, wherein the condition of controlling the first contact reaction makes the content of monocyclic aromatic hydrocarbons in the heavy hydrogenated diesel oil obtained in step (2) to be 50% by weight % or more, the nitrogen content is less than 50 μg/g; preferably,

The conditions of the first contact reaction are controlled such that the content of monocyclic aromatic hydrocarbons in the heavy hydrogenated diesel oil obtained in step (2) is more than 60% by weight, and the nitrogen content is less than 30 μg/g.

9. The method according to any one of claims 1-4 and 8, wherein the conditions for the first contact reaction include: a hydrogen partial pressure of 3.0-13.0 MPa, preferably 4.0-9.0 MPa; a reaction temperature of 300～450℃, preferably 330～410℃; hydrogen oil volume ratio is 400～2000Nm ³ /m ³ , preferably 500～1500Nm ³ /m ³ ; liquid hourly volume space velocity is 0.2～5.0h ^-1 , preferably 0.5～3.0h ^-1 .

10 . The method according to claim 1 , wherein the conditions for the second contact reaction include: the partial pressure of hydrogen is 3.0-13.0 MPa, preferably 4.0-9.0 MPa; the reaction temperature is 300-450° C., preferably 330° C. 11 . ～440℃; the volume ratio of hydrogen to oil is 400～2000Nm ³ /m ³ , preferably 500～1500Nm ³ /m ³ ; the liquid hourly volume space velocity is 0.4～8.0h ^-1 , preferably 0.7～4.0h ^-1 .

11. The method of any one of claims 1-4, wherein the ratio of the packing volume of the hydrotreating catalyst in the hydrotreating reactor to the hydrocracking catalyst in the hydrocracking reactor It is (0.2-5):1, Preferably it is (0.5-2):1.

12 . The method according to claim 1 , wherein, in terms of oxides and based on the hydrotreating catalyst, the content of the carrier contained in the hydrotreating catalyst and the content of the carrier supported on the carrier is 1-10 . 13 . % by weight of group VIII non-noble metal elements and/or content of 10-45% by weight of group VIB non-noble metal elements.

13. The method of claim 12, wherein the group VIII non-noble metal element is cobalt and/or nickel, and the group VIB non-noble metal element is molybdenum and/or tungsten.

14. The method according to claim 1, wherein the hydrocracking catalyst contains a carrier and metal element tungsten as an active component, and the carrier is a mixture containing a solid acid component and a heat-resistant inorganic oxide, The solid acid component is silica-alumina and/or Y-type zeolite, and the heat-resistant inorganic oxide is at least one of alumina, silica and alumina-silica.

15. The method according to claim 14, wherein, in the hydrocracking catalyst, based on the carrier therein, the content of the solid acid component is 0.5-95 wt%, the heat-resistant inorganic oxidation The content of the material is 5 to 99.5% by weight; preferably,

In the hydrocracking catalyst, based on the carrier therein, the content of the solid acid component is 1-80% by weight, and the content of the heat-resistant inorganic oxide is 20-99% by weight.

16. The method according to claim 14 or 15, wherein the content of tungsten in the hydrocracking catalyst is 1 to 50% by weight, preferably 5% by weight, calculated as oxide and based on the hydrocracking catalyst. -40% by weight, more preferably 8 - 30% by weight.

17. The method according to claim 14, wherein the solid acid component is a Y-type zeolite, and the Y-type zeolite is selected from the group consisting of HY, rare earth Y, rare earth HY zeolite, ultrastable Y, rare earth ultrastable Y zeolite, At least one of partially amorphized Y zeolite, titanium-containing Y zeolite, and phosphorus-containing Y.

18. The method according to claim 14 or 17, wherein the Y-type zeolite is a WY-type zeolite, and the content of W in the WY-type zeolite accounts for the amount of oxide in the hydrocracking catalyst as an active component. The amount of the metal element tungsten calculated as WO ₃ is 3-80% by weight, preferably 5-40% by weight.