Background technology
Development of world economy is rapid at present, and is more and more to the demand of fuel oil.The reserves that world's crude oil has been verified calculate by present produced quantity, can only keep the lasting use in over one hundred year, and oil belongs to Nonrenewable energy resources, are faced with exhausted day by day crisis, press for the exploitation substitute energy like this.The coal reserves of China is very abundant, and coal is mainly by hydrocarbon etc. elementary composition, and therefore using coal production oil fuel is a kind of very effective approach.The major technique of coal system oil comprises DCL/Direct coal liquefaction and ICL for Indirect Coal Liquefaction at present, but these technical sophistications, the cost height is difficult to large-scale promotion.
Coal tar is the byproduct of coking industry, and it is formed based on aromatic hydrocarbons.Along with quick growth international, domestic steel industry, coking industry also develops rapidly thereupon, and the output of coal tar also constantly increases, and the cleaning processing and utilization of coal tar becomes more and more important.Current, the method that more domestic coal tar manufacturing enterprises handle coal tar is mainly Chemicals such as going out phenol, naphthalene through extraction separation behind the acid-alkali refining or as the low-quality fuel oil burning that directly acts as a fuel after burning or the emulsification, not only deficiency in economic performance, and contaminate environment.
Coal tar hydrogenating system clean fuel oil just has research as far back as last century three, the forties, but because reaction pressure is very high, does not all realize industrialization, and the eighties Japan has developed this technology up to last century.The part unit of China has also developed coal tar hydrogenation catalyst, mainly is to make by catalyzer used in the petrochemical complex is improved.
CN1464031A discloses a kind of coal tar hydrotreating process and catalyzer, and this process using hydrofining and hydro-upgrading one-stage serial are by coal tar production high-quality petroleum naphtha and fine-quality diesel oil.This technology has been selected titaniferous Hydrobon catalyst specially, the catalyst for hydro-upgrading that contains titanium oxide and molecular sieve, but because the structure of the water that coal tar hydrogenating generates meeting saboteur sieve catalyst makes the deactivation rate of catalyst for hydro-upgrading fast, running period is short.
US4855037 has introduced the hydroprocessing process of a kind of coal tar or coal-tar pitch, and the coal tar after the hydrotreatment is used for delayed coking is applicable to the preparation Graphite Electrodes with production super acicular coke.This method is mainly used in the pre-treatment of delayed coking, not production purpose product, and the working pressure height, investment is big.
Summary of the invention
The object of the present invention is to provide a kind of coal tar to produce the technology and the method for preparing catalyst of clean fuel oil product, this technology can maximally utilise coal tar raw material, obtain fine lightweight cleaning product, simultaneously catalyzer has long, characteristics such as hydrogenation efficiency is high and running is stable of life-span.
The method of producing clean fuel oil by hydrogenation of coal tar of the present invention comprises that the following step poly-:
(1) coal tar raw material dewater to water content less than 0.05%, remove mechanical impurity then, the coal tar raw material that is purified.Coal tar after the purification is cut into coal tar lighting end and coal tar heavy fractioning through normal pressure distillation and/or underpressure distillation, cut point is 320~360 ℃, from the lightweight distillate, cut 170~210 ℃ of carbolic oil cuts and 210~230 ℃ of naphtalene oil cuts simultaneously, and therefrom extracting phenol and naphthalene, the full cut after remainder and coal tar lighting end, last running and the purification is as the raw material of producing clean fuel oil by hydrogenation;
(2) stock oil of step (1) gained with enter the hydrofining reaction district after hydrogen mixes, with the Hydrobon catalyst contact reacts, remove impurity such as wherein metal, sulphur, nitrogen, oxygen, described Hydrobon catalyst is a loaded catalyst, carrier is an activated alumina, and active ingredient is Co, Mo, the base metals such as W, Ni of VIII family and/or group VIB.Hydrofining reactor is typical fixed-bed reactor, catalyzer adopts classification filling technology, and operation condition is: 300~460 ℃ of average reaction temperature, hydrogen dividing potential drop are 8.0~16.0MPa, the volume ratio of hydrogen oil is 800~3000, and volume space velocity is 0.2~4.0h during liquid
-1Oily for the full cut of coal tar is when reaction raw materials, raw material needed before entering the hydrofining reaction district through changeable hydrogenation protecting reactor, filling hydrogenation protecting agent in the reactor, and number of reactors is 1~4, can be according to the flexible modulation of material characteristic;
(3) effluent in hydrofining reaction district can directly enter separation system, carries out the product cutting, also can enter the hydro-upgrading reaction zone, with the catalyst for hydro-upgrading contact reacts, and like this can be according to the flexible modulation of material characteristic.Described Hydrobon catalyst is to load on the VIII family on the modified kaolin and/or the non-precious metal catalyst of group VIB, and wherein VIII family metal is selected from Co, Ni, and the group VIB metal is selected from Mo, W.Described hydrofining reactor is typical fixed-bed reactor, catalyzer adopts classification filling technology, and operation condition is: 300~440 ℃ of average reaction temperature, hydrogen dividing potential drop are 8.0~16.0MPa, the volume ratio of hydrogen oil is 800~3000, and volume space velocity is 0.2~4.0h during liquid
-1
(4) step (3) gained reaction effluent obtains diesel oil distillate and naphtha fraction through cooling, high-low pressure separation and fractionation.
In the coal tar production process, the difference of dry distillation of coal temperature, coal tar can be divided into coal-tar heavy oil and middle coalite tar.Wherein middle coalite tar density is usually at 1.0g/cm
3Below, aromaticity content is less, and alkane content is more.And the density of coal-tar heavy oil is usually greater than 1.0g/cm
3, asphalt content is up to 50%, even more, alkane content seldom, other main components are many rings and condensed-nuclei aromatics, and contain higher sulphur, nitrogen, metal impurities.Coal tar character composition that the more important thing is the different process by-product also has very big-difference, and complicated various processing to tar of raw material brought very big difficulty.Coalite tar during combination process provided by the present invention can be handled also is fit to more unmanageable coal-tar heavy oil.
Described hydrogenating materials can be<360 ℃ tar lighting end, and can be the full cut of coal tar that purifies, the also coal tar and the mixture of lighting end or dephenolize arbitrarily, naphthalene lighting end arbitrarily.Raw material range has been widened in the mediation of feed composition, utilize the similar compatibility principle simultaneously, utilize the component that is difficult for processing in the high fragrant distillate dilution coal tar, the sulphur in the raw material, nitrogen and metal impurities content had both been reduced, thereby also reduced the hydrogenation difficulty, and, increase economic efficiency to the requirement of hydrogenation unit.
Described hydrogenation conditions is: 300~460 ℃ of hydrofining reactor average reaction temperature, hydrogen dividing potential drop are 8.0~16.0MPa, and the volume ratio of hydrogen oil is 500~2000, and volume space velocity is 0.2~4.0h during liquid
-1300~440 ℃ of hydro-upgrading reactor average reaction temperature, hydrogen dividing potential drop are 8.0~16.0MPa, and the volume ratio of hydrogen oil is 500~2000, and volume space velocity is 0.2~4.0h during liquid
-1Preferred reaction conditions is: 340~410 ℃ of hydrofining reactor average reaction temperature, hydrogen dividing potential drop are 8.0~12.0MPa, and the volume ratio of hydrogen oil is 800~1600, and volume space velocity is 0.5~1.5h during liquid
-1320~400 ℃ of hydro-upgrading reactor average reaction temperature, stagnation pressure are 8.0~16.0MPa, and the volume ratio of hydrogen oil is 800~1600, and volume space velocity is 0.5~1.5h during liquid
-1
Changeable hydrogenation protecting device number of the present invention is 1~4, and preferred 2~3, protective material is acid ore deposit soil and/or zinc oxide etc.
Hydrofining reaction of the present invention district adopts two or more catalyzer grading loadings.Described hydro-upgrading reaction zone can only load a kind of catalyzer, also can be with two or more catalyzer grading loadings.Carry out the upgrading processing to generating oil after hydrofining, further diesel product character has especially improved diesel-fuel cetane number.The hydro-upgrading reactor can replenish cold new hydrogen and reach the reactive hydrogen oil ratio and control the bed temperature of reaction.Carbon residue and metal content height in the coal tar lighting end; too fast for preventing the beds pressure drop; a certain amount of protective material of can packing into before Hydrobon catalyst, with the assurance device long-term operation, the protective material amount of changing over to is 5~30% of a Hydrobon catalyst volume.
Hydrobon catalyst of the present invention, its active ingredient NiO, MoO
3, CoO, WO
3One or more, account for 5%~30% of catalyzer total amount, optimum is 10~20%, all the other are active aluminum oxide carrier, the Preparation of catalysts method comprises the steps:
(1) preparing carriers
Activated alumina is the catalyst support material that clear green source, Beijing company produces, and ## pulverizes carrier, gets 20~40 order activated alumina particles, and roasting in 500~850 ℃ of retort furnaces then, roasting finish the back and lower the temperature naturally, and be standby;
(2) Preparation of Catalyst
With a kind of and/or several mixture in Nickelous nitrate hexahydrate, ammonium molybdate, Cobaltous nitrate hexahydrate, the ammonium tungstate, under 20~60 ℃ of conditions, add in the deionized water, adding concentration is 5% ammoniacal liquor adjusting pH value, metal-salt is dissolved fully make solution, under 20~80 ℃ of temperature, adopt the carrier of equi-volume impregnating with this this solution impregnation step (1) preparation, dipping time is 0.5~8h, naturally dry in the shade, roasting in 350~550 ℃ of air atmospheres at last, roasting time is 2~6h, makes catalyzer.Catalyst for hydro-upgrading of the present invention, it is characterized in that catalyzer is made up of carrier and active ingredient: carrier is a modified kaolin, and method of modifying adds acid soak, drying for standby after being 650~1000 ℃ of high-temperature calcinations.Acid is the protonic acid of concentration 1~5mol/L, example hydrochloric acid, sulfuric acid, nitric acid, acetic acid etc.Active ingredient is the VIII transition metal oxide, as NiO, MoO
3, CoO, WO
3One or more, account for 10~35% of catalyzer total mass, carrier accounts for 65~90% of catalyzer total mass, described carrier is a modified kaolin, above percentage number average is in oxide dry basis.The Preparation of catalysts method comprises the steps:
(1) preparing carriers
Purity is greater than 98% kaolin, keep 2~6h oven dry at 120~200 ℃, heat up with segmented program then, at first be warming up to 400 ℃ with 10~20 ℃/min speed, keep 0.5~5h, the back is warming up to 600~1000 ℃ with the speed of 5~15 ℃/min, calcining 0.5~8h, calcining finishes the nature cooling, obtains the kaolin of thermal treatment modification, kaolin after the thermal treatment is carried out acid dipping to be handled, 60~80 ℃ of its bath temperatures, dipping time is 4~10h, flooding used acid is protonic acid, its concentration is 1.0~5.0mol/L, and addition is 25g kaolin/100mL protonic acid;
(2) Preparation of Catalyst
With Nickelous nitrate hexahydrate, ammonium molybdate, Cobaltous nitrate hexahydrate, a kind of and/or several mixture in the ammonium tungstate, under 20~60 ℃ of conditions, add in the deionized water, make solution, under 20~60 ℃ of temperature, carrier with this solution impregnation step (1) preparation, dipping time is 1~10h, after perhaps this solution being used spray saturation method impregnated carrier, leave standstill 1~12h under the room temperature, then it is carried out drying under 60~140 ℃ of constant temperature, be 4~12h time of drying, afterwards, roasting in the air atmosphere under 350~550 ℃ of temperature, roasting time is 2~6h, makes catalyzer.
The shared cover separation system of hydrofining effluent and hydro-upgrading effluent among the present invention, flow process can reduce facility investment again by flexible modulation like this.Can be used as recycle hydrogen behind the hydrogen-rich gas purifying by the separation system gained and use, water is discharged reactive system.
Embodiment
Below in conjunction with accompanying drawing technology provided by the present invention is further detailed.
Accompanying drawing is the schematic flow sheet of producing clean fuel oil by hydrogenation of coal tar combination process provided by the present invention.Some utility appliance among the figure such as interchanger etc. do not mark, but are known to those of ordinary skills.
The flow process of producing clean fuel oil by hydrogenation of coal tar combination process provided by the present invention is as follows:
From the stock oil of pipeline 3 through feedstock pump 4 with enter preheating premixed device 6 from pipeline 1 and after the hydrogen of membrane compressor 2 pressurizations mixes in pipeline 16; after carrying out pre-warm premixing; enter changeable protective material reactor 7 through pipeline 17; enter hydrofining reactor 8 through pipeline 18; this step is decided by feedstock property; raw material impurity content directly enters hydrofining reactor 8 through pipeline 20 behind the warm premixing more in advance; with the Hydrobon catalyst contact reacts; reaction stream is gone out and is entered hydro-upgrading reactor 9 through pipeline 19; with the catalyst for hydro-upgrading contact reacts, hydro-upgrading reactor 9 replenishes the new hydrogen of part by pipeline 1 and keeps the required hydrogen-oil ratio of reaction and reduce reaction bed temperature.Stock oil with also can directly enter reactor 9 after hydrogen mixes and carry out one-stage hydrogenation through pipeline 20 and pipeline 21, this is according to the flexible modulation of stock oil character.The reaction effluent that comes out from reactor 9 enters high-pressure separator 10 through pipeline 22, isolate gas phase 13 and be hydrogen-rich gas, utilize again after the purification, liquid phase enters light pressure separator 11 through pipeline 23 and further separates, separated product enters separation column 12 through pipeline 24, cut out product 14 petroleum naphthas, product 15 diesel oil.Pipeline 5 purges the reaction pipeline during start-stop car for purging nitrogen.
The present invention illustrates with following embodiment, but the present invention is not limited to following embodiment, under the scope of described aim, changes and implements to be included in the technical scope of the present invention before and after not breaking away from.
The stock oil character that embodiment uses sees Table 1 (wherein wt% is weight percentage).1# stock oil is the full cut of coal tar, from certain coal chemical enterprise; 2# stock oil is the coal tar<360 ℃ tar lighting end parts except that phenol and naphthalene; The 3# stock oil mixed fraction that to be 1#, 2# stock oil obtain by 1: 1 mass ratio.
Hydrobon catalyst A used in the example is the self-control Hydrobon catalyst, with the activated alumina is carrier, one or more of Mo, Ni, Co, W are the catalyzer of reactive metal, catalyst for hydro-upgrading B, C, D be homemade be carrier with the modified kaolin, one or more of Mo, Ni, Co, W are the catalyzer of reactive metal, and concrete proportioning sees Table 2.
Embodiment 1
With a kind of coal-tar heavy oil is raw material; note is made 1# stock oil; its character sees Table 1; pre-treatment removes and anhydrates and mechanical impurity; with enter 2 sections hydrogenation protecting reactors after high pressure hydrogen mixes; pre-hydrogenation is after hydrofining reactor and hydro-upgrading reactor reaction, and operational condition sees Table 3, and product property sees Table 4.Protective material is acid ore deposit soil and 7: 3 by volume mixed packings of zinc oxide, and Hydrobon catalyst and catalyst for hydro-upgrading are respectively A, B, forms to see Table 2.
Embodiment 2
With a kind of coal-tar heavy oil is raw material; note is made 1# stock oil; its character sees Table 1; pre-treatment removes and anhydrates and mechanical impurity; with enter 3 sections hydrogenation protecting reactors after high pressure hydrogen mixes; pre-hydrogenation is after hydrofining reactor and hydro-upgrading reactor reaction, and operational condition sees Table 3, and product property sees Table 4.Protective material is acid ore deposit soil and 7: 3 by volume mixed packings of zinc oxide, and Hydrobon catalyst and catalyst for hydro-upgrading are respectively A, B, forms to see Table 2.
Embodiment 3
With the coal tar<360 ℃ tar lighting end except that phenol and naphthalene partly is stock oil, and note is made 2# stock oil, and its character sees Table 1, and after pre-treatment removed and anhydrates, through hydrofining reactor and hydro-upgrading reactor reaction, operational condition saw Table 3, and product property sees Table 4.Hydrobon catalyst and catalyst for hydro-upgrading are respectively A, C, form to see Table 2.Catalyzer is taked grading loading in the hydrofining reactor, and the hydrogenation protecting agent of its volume 15% of filling before Hydrobon catalyst, hydrogenation protecting agent are acid ore deposit soil and 7: 3 by volume mixed systems of zinc oxide.
Embodiment 4
With the coal tar<360 ℃ tar lighting end except that phenol and naphthalene partly is stock oil, and note is made 2# stock oil, and its character sees Table 1, and after pre-treatment removed and anhydrates, through hydrofining reactor and hydro-upgrading reactor reaction, operational condition saw Table 3, and product property sees Table 4.Hydrobon catalyst and catalyst for hydro-upgrading are respectively A, C, form to see Table 2.Catalyzer is taked grading loading in the hydrofining reactor, and the hydrogenation protecting agent of its volume 15% of filling before Hydrobon catalyst, hydrogenation protecting agent are acid ore deposit soil and 7: 3 by volume mixed systems of zinc oxide.
Embodiment 5
With the coal tar<360 ℃ tar lighting end except that phenol and naphthalene partly is stock oil; note is made 2# stock oil; its character sees Table 1; pre-treatment removes and anhydrates and mechanical impurity; with enter 1 section hydrogenation protecting reactor after high pressure hydrogen mixes; pre-hydrogenation is after hydrofining reactor and hydro-upgrading reactor reaction, and operational condition sees Table 3, and product property sees Table 4.Hydrobon catalyst and catalyst for hydro-upgrading are respectively A, D, form to see Table 2.Catalyzer is taked grading loading in the hydrofining reactor, and the hydrogenation protecting agent of its volume 15% of filling before Hydrobon catalyst, hydrogenation protecting agent are acid ore deposit soil and 7: 3 by volume mixed systems of zinc oxide.
Embodiment 6
With the coal tar<360 ℃ tar lighting end except that phenol and naphthalene partly is stock oil; note is made 2# stock oil; its character sees Table 1; pre-treatment removes and anhydrates and mechanical impurity; with enter 1 section hydrogenation protecting reactor after high pressure hydrogen mixes; pre-hydrogenation is after hydrofining reactor and hydro-upgrading reactor reaction, and operational condition sees Table 3, and product property sees Table 4.Hydrobon catalyst and catalyst for hydro-upgrading are respectively A, C/D, form to see Table 2.Catalyzer is taked grading loading in the hydrofining reactor, and the hydrogenation protecting agent of its volume 15% of filling before Hydrobon catalyst, hydrogenation protecting agent are acid ore deposit soil and 7: 3 by volume mixed systems of zinc oxide.1: 1 by volume grading loading of hydro-upgrading catalyst reactor C and D.
Table 1 stock oil character
Stock oil |
??1# |
??2# |
??3# |
Density/gcm
-3 |
??1.1189 |
??0.9663 |
??0.9823 |
??C,wt% |
??90.39 |
??92.06 |
??91.25 |
??H,wt% |
??5.37 |
??5.88 |
??5.65 |
Total sulfur content, μ g/g |
??5500 |
??2800 |
??4900 |
Total nitrogen content, μ g/g |
??9600 |
??12900 |
??10000 |
Stock oil |
??1# |
??2# |
??3# |
Carbon residue, wt% |
??25.8 |
??0.78 |
??12.5 |
Mechanical impurity, wt% |
??6.23 |
??<0.1 |
??4.11 |
Metal content, μ g/g |
??128.1 |
??90.5 |
??112.3 |
Aromaticity content, wt% |
??36.7 |
??99.0 |
??75.1 |
Colloid, wt% |
??20.5 |
??- |
??10.1 |
Bituminous matter, wt% |
??38.5 |
??- |
??20.3 |
Table 2 catalyzer is formed (all in oxide dry basis, mass percent)
The catalyzer title |
Carrier |
Active ingredient |
A |
Activated alumina 75% |
MoO
3: 15%, NiO:10%
|
B |
Modified kaolin 74% |
MoO
3: 20%, NiO:6%
|
C |
Modified kaolin 75% |
MoO
3: 16%, NiO:6%., Co:3%
|
D |
Modified kaolin 74% |
MoO
3: 16%, NiO:6%.,CoO:3%,WO
3:1%
|
Table 3 operating procedure condition
|
Embodiment 1 |
Embodiment 2 |
Embodiment 3 |
Embodiment 4 |
Embodiment 5 |
Embodiment 6 |
Stock oil |
??1# |
??1# |
??2# |
??2# |
??3# |
??3# |
The hydrofining condition |
|
|
|
|
|
|
Catalyzer |
??A |
??A |
??A |
??A |
??A |
??A |
Pressure/MPa |
??10 |
??12 |
??10 |
??14 |
??10 |
??15 |
Medial temperature/℃ |
??350 |
??365 |
??350 |
??369 |
??350 |
??370 |
|
Embodiment 1 |
Embodiment 2 |
Embodiment 3 |
Embodiment 4 |
Embodiment 5 |
Embodiment 6 |
Volume space velocity/h
-1 |
??0.5 |
??0.8 |
??0.5 |
??0.6 |
??0.5 |
??0.4 |
Hydrogen to oil volume ratio |
??800 |
??800 |
??800 |
??700 |
??800 |
??700 |
The hydro-upgrading condition |
|
|
|
|
|
|
Catalyzer |
??B |
??B |
??C |
??C |
??D |
??C/D |
Pressure/MPa |
??10 |
??12 |
??10 |
??14 |
??10 |
??15 |
Medial temperature/℃ |
??363 |
??375 |
??360 |
??378 |
??368 |
??380 |
Volume space velocity/h
-1 |
??0.5 |
??0.8 |
??0.5 |
??0.6 |
??0.5 |
??0.4 |
Hydrogen to oil volume ratio |
??500 |
??600 |
??500 |
??700 |
??500 |
??800 |
Table 4 product property
Table 4 product property (continuous table)