CN111863145B - Low-temperature coal tar full-fraction hydrocracking lumped dynamics model modeling method - Google Patents
Low-temperature coal tar full-fraction hydrocracking lumped dynamics model modeling method Download PDFInfo
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- 239000011280 coal tar Substances 0.000 title claims abstract description 176
- 238000000034 method Methods 0.000 title claims abstract description 81
- 238000004517 catalytic hydrocracking Methods 0.000 title claims abstract description 63
- 239000003054 catalyst Substances 0.000 claims abstract description 109
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 62
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 46
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 41
- 239000011593 sulfur Substances 0.000 claims abstract description 41
- 238000006477 desulfuration reaction Methods 0.000 claims abstract description 39
- 230000023556 desulfurization Effects 0.000 claims abstract description 39
- 230000008569 process Effects 0.000 claims abstract description 39
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 37
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 34
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 28
- 230000000694 effects Effects 0.000 claims abstract description 28
- 239000001301 oxygen Substances 0.000 claims abstract description 28
- 150000001875 compounds Chemical class 0.000 claims abstract description 22
- 238000006243 chemical reaction Methods 0.000 claims description 274
- 239000000047 product Substances 0.000 claims description 89
- 238000012937 correction Methods 0.000 claims description 33
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 19
- 239000001257 hydrogen Substances 0.000 claims description 19
- 229910052739 hydrogen Inorganic materials 0.000 claims description 19
- 230000004913 activation Effects 0.000 claims description 16
- 230000009467 reduction Effects 0.000 claims description 14
- 230000009849 deactivation Effects 0.000 claims description 12
- 239000002994 raw material Substances 0.000 claims description 12
- 239000007788 liquid Substances 0.000 claims description 11
- 238000006392 deoxygenation reaction Methods 0.000 claims description 10
- 239000006227 byproduct Substances 0.000 claims description 9
- 238000007086 side reaction Methods 0.000 claims description 7
- 238000010586 diagram Methods 0.000 claims description 5
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims description 5
- 238000013213 extrapolation Methods 0.000 claims description 4
- 229910017464 nitrogen compound Inorganic materials 0.000 claims description 4
- 239000007795 chemical reaction product Substances 0.000 claims description 3
- 239000003502 gasoline Substances 0.000 claims description 3
- 238000005121 nitriding Methods 0.000 claims description 3
- 230000003647 oxidation Effects 0.000 claims description 3
- 238000007254 oxidation reaction Methods 0.000 claims description 3
- 238000012360 testing method Methods 0.000 claims description 3
- 150000002927 oxygen compounds Chemical class 0.000 claims description 2
- 230000035484 reaction time Effects 0.000 claims description 2
- 238000007670 refining Methods 0.000 claims description 2
- 238000005984 hydrogenation reaction Methods 0.000 abstract description 35
- 239000003921 oil Substances 0.000 abstract description 20
- 230000008859 change Effects 0.000 abstract description 12
- 238000011160 research Methods 0.000 abstract description 9
- 239000000295 fuel oil Substances 0.000 abstract description 3
- 238000003889 chemical engineering Methods 0.000 abstract description 2
- 238000002474 experimental method Methods 0.000 description 16
- 238000002360 preparation method Methods 0.000 description 11
- 230000006872 improvement Effects 0.000 description 8
- LOTCVJJDZFMQGB-UHFFFAOYSA-N [N].[O].[S] Chemical compound [N].[O].[S] LOTCVJJDZFMQGB-UHFFFAOYSA-N 0.000 description 4
- 239000003245 coal Substances 0.000 description 4
- 239000002131 composite material Substances 0.000 description 3
- -1 nitrogen-containing compound Chemical class 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000012795 verification Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000004821 distillation Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000000197 pyrolysis Methods 0.000 description 2
- 238000005987 sulfurization reaction Methods 0.000 description 2
- 229930192474 thiophene Natural products 0.000 description 2
- 150000003577 thiophenes Chemical class 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- PFRUBEOIWWEFOL-UHFFFAOYSA-N [N].[S] Chemical compound [N].[S] PFRUBEOIWWEFOL-UHFFFAOYSA-N 0.000 description 1
- ZQRGREQWCRSUCI-UHFFFAOYSA-N [S].C=1C=CSC=1 Chemical compound [S].C=1C=CSC=1 ZQRGREQWCRSUCI-UHFFFAOYSA-N 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
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- 150000001735 carboxylic acids Chemical class 0.000 description 1
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- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 239000010779 crude oil Substances 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
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- 150000002391 heterocyclic compounds Chemical class 0.000 description 1
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- 230000000704 physical effect Effects 0.000 description 1
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- 239000000376 reactant Substances 0.000 description 1
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- 238000000638 solvent extraction Methods 0.000 description 1
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- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
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- C10G47/00—Cracking of hydrocarbon oils, in the presence of hydrogen or hydrogen- generating compounds, to obtain lower boiling fractions
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Abstract
The invention discloses a method for modeling a lumped dynamic model of low-temperature coal tar full-fraction hydrocracking, and belongs to the technical field of chemistry and chemical engineering. According to the invention, the kinetic research is carried out on the coal tar hydrofining, the established kinetic model considers the attenuation of the catalyst activity and the influence of technological conditions such as temperature, pressure, airspeed and the like on the product property, the hydrofining process has four main targets of definite desulfurization, denitrification, deoxidization and oil product lightening, and the compound in the coal tar can be relatively simply lumped divided during the kinetic research. By establishing a set of HDS dynamic model, HDN dynamic model, HDO dynamic model and fuel oil yield dynamic model in the coal tar hydrogenation process, the sulfur, nitrogen and oxygen contents and the yield of the target product of the hydrogenation product under different airspeed, pressure and temperature parts are accurately predicted, and the change of the product property under long-period operation can be predicted.
Description
Technical Field
The invention belongs to the technical field of chemistry and chemical engineering, and relates to a method for modeling a lumped kinetic model of low-temperature coal tar full-fraction hydrocracking.
Background
The development of the energy industry directly affects the national economic prosperity and long-term security, and determines whether each economic planning and development can be smoothly carried out. Because China has the resource status quo of 'lean oil, less gas and more coal', how to develop the utilization mode of coal resources as much as possible is important. Coal tar hydrogenation technology is an important component in this field. Coal tar becomes an important crude oil substitute, and has great strategic value and practical significance for adjusting and supplementing the energy structure in China aiming at the research of the coal tar hydrogenation technology.
The concept of lumped dynamics is to consider a complex reaction system as a virtual lumped component of pure compounds, and then to build up these virtual lumped reaction networks and kinetic models. The prior literature has few lumped dynamic researches on coal tar hydrogenation, mainly focuses on the hydrogenation research of medium-low temperature coal tar of cut fractions, and the lumped division is limited on the idea of fixed distillation range division. In the past research on hydrocracking, the chemical composition in coal tar has generally been divided into 8 to 16 types of lumped components. For example, dai F et al verify that the equation has good interpretation and prediction ability based on the lumped kinetic equation of carbon number, reactor modeling and coal tar hydrogenation process through experiments. However, the study on the carbon number is complicated and the study object is not obvious.
Because sulfur and nitrogen compounds in coal tar can cause great pollution to the environment, oxygen-containing compounds can reduce the heat value of fuel to cause unstable combustion, and can cause negative effects such as equipment corrosion. Therefore, the research on the removal of sulfur, nitrogen and oxygen impurities in low-temperature coal tar is particularly important, and the establishment of a corresponding kinetic model for further explaining the reaction rule of coal tar hydrocracking is a technical key point and difficulty to be solved urgently in the art.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide a method for modeling a lumped kinetic model of low-temperature coal tar full-fraction hydrocracking. The method can accurately predict the sulfur, nitrogen and oxygen contents of hydrogenation products under different airspeeds, pressures and temperatures and the yield of target products, and can also predict the change of product properties under long-period operation.
In order to achieve the above purpose, the invention is realized by adopting the following technical scheme:
the invention discloses a modeling method of a low-temperature coal tar full-fraction hydrocracking lumped kinetic model, which specifically comprises the following steps:
1) Carrying out lumped dynamic component division on the hydrocracking reaction;
2) Establishing a lumped dynamics model basic assumption;
3) Constructing a hydrocracking total reaction network diagram;
4) Establishing a hydrocracking lumped dynamics model;
5) Determining kinetic parameters of each reaction and determining an objective function;
6) And (3) verifying a model: and the extrapolation performance and the prediction capability of the established low-temperature coal tar hydrocracking kinetic model are verified through experimental comparison.
Preferably, the hydrocracking reaction in step 1) includes a feedstock hydrocracking reaction and a produced oil hydrocracking reaction; the hydrocracking reaction of the raw oil is divided by the sulfur, nitrogen and oxygen compounds after the reaction, and the hydrocracking reaction of the generated oil is divided by the sulfur content and the nitrogen content in the product;
wherein the component division of the lumped dynamics comprises lumped 1-sulfur compounds, lumped 2-nitrogen compounds, lumped 3-oxygen compounds; wherein, the lumped 1, the lumped 2 and the lumped 3 are all compounds in the hydrocracking reaction product.
Preferably, in the step 4), all sulfur-containing compounds in the coal tar are divided into a whole for reaction kinetics modeling, and the conversion degree of the coal tar hydrocracking reaction is reacted by reducing the sulfuration content in the coal tar; namely, the coal tar desulfurization reaction kinetic model HDS is preliminarily expressed as:
in which W is S Representing the mass fraction of sulfur in coal tar; k represents the reaction rate of the coal tar desulfurization reaction kinetic model HDS; n is n s The reaction progression is shown.
Further preferably, in step 4), when the reaction number n is s Not equal to 1 or the reaction series n s At=1, considering the catalyst deactivation factor and the grading effect of the catalyst species, the coal tar desulfurization reaction kinetic model HDS is expressed as:
wherein: w (W) inlet,s And W is outlet,s Respectively representing the mass fractions of sulfur in the feed coal tar and the discharge coal tar;represents hydrogen partial pressure, MPa; LHSV denotes liquid volumetric flow rate, h -1 ；a s Representing a reaction space velocity correction coefficient; b s Representing a pressure correction coefficient; t represents the reaction temperature of desulfurization reaction, K; r represents a pervasive factor, 8.314J/moL; t represents the operation time of the desulfurization reaction device; t is t c,s Shows half life time as a desulfurization catalyst; beta S The correction coefficient of the catalyst life in the HDS reaction of the coal tar; y is i The grading proportion of different catalysts in the desulfurization reaction is shown; e (E) a,si The reaction activation energy corresponding to different catalysts in the desulfurization reaction is shown; k (k) 0,si Indicating the pre-finger factors of the Arrhenius equation for different catalysts in the desulfurization reaction.
Preferably, in the step 4), all nitrogen-containing compounds in the coal tar are divided into a whole for reaction kinetics modeling, and the conversion degree of the coal tar hydrocracking reaction is reacted by reducing the nitriding content in the coal tar; namely, the coal tar denitrification reaction kinetic model HDN is preliminarily expressed as:
in which W is N Representing the mass fraction of nitrogen in the coal tar; k represents the reaction rate of the coal tar denitrification reaction kinetic model HDN; n is n s The reaction progression is shown.
Further preferably, in step 4), when the reaction number n is s Not equal to 1 or the reaction series n s At=1, considering the catalyst deactivation factor and the grading effect of the catalyst species, the coal tar denitrification reaction kinetic model HDN is expressed as:
wherein: w (W) inlet,N And W is outlet,N Respectively representing the mass fractions of nitrogen in the feed coal tar and the discharge coal tar; p is p H2 Represents hydrogen partial pressure, MPa; LHSV denotes liquid volumetric flow rate, h -1 ；a N Representing a reaction space velocity correction coefficient; b N Representing a pressure correction coefficient; t represents the reaction temperature of denitrification reaction, K; r represents a pervasive factor, 8.314J/moL; t represents the operation time of the denitrification reaction apparatus; t is t c,N Shows half life time as a catalyst in denitrification reaction; beta N The correction coefficient of the catalyst life in the HDN reaction of the coal tar; y is i Representing the grading proportion of different catalysts in the denitrification reaction; e (E) a,Ni The reaction activation energy corresponding to different catalysts in the denitrification reaction is represented; k (k) 0,Ni Indicating the pre-pointing factors of the Arrhenius equation for different catalysts in the denitrification reaction.
Preferably, in the step 4), all oxygen-containing compounds in the coal tar are divided into a whole to carry out reaction kinetics modeling, and the conversion degree of the coal tar hydrocracking reaction is reacted by reducing the oxidation content in the coal tar; namely, the coal tar deoxidization reaction kinetic model HDO is preliminarily expressed as:
in which W is O Representing the mass fraction of oxygen in the coal tar; k represents the reaction rate of the coal tar deoxidation reaction kinetic model HDO; n is n s The reaction progression is shown.
Further preferably, in step 4), when the reaction number n is s Not equal to 1 or the reaction series n s At=1, considering the catalyst deactivation factor and the grading effect of the catalyst species, the coal tar deoxygenation reaction kinetic model HDO is expressed as:
wherein: w (W) inlet,O And W is outlet,O Respectively representing the mass fractions of oxygen in the feed coal tar and the discharge coal tar; p is p H2 Represents hydrogen partial pressure, MPa; LHSV denotes liquid volumetric flow rate, h -1 ；a O Representing a reaction space velocity correction coefficient; b O Representing a pressure correction coefficient; t represents the reaction temperature of the deoxidation reaction, K; r represents a pervasive factor, 8.314J/moL; t represents the operation time of the deoxidizing reaction apparatus; t is t c,O Indicating the half life time of the catalyst in the deoxygenation reaction; beta O The correction coefficient of the catalyst life in the HDO reaction of the coal tar; y is i The grading proportion of different catalysts in the deoxidation reaction is shown; e (E) a,Oi The reaction activation energy corresponding to different catalysts in the deoxidation reaction is shown; k (k) 0,Oi Indicating the pre-pointing factors of the Arrhenius equation for the different catalysts in the deoxygenation reaction.
Preferably, in step 4), the coal tar is converted into gasoline, diesel and byproducts which are target products in the refining process of the hydrocracking reaction, and the reaction of the target products and the byproducts is adopted to conform to a 1-level reaction dynamics model by considering the grading proportion and the hydrogen partial pressure of the catalyst, so that the target product dynamics model is expressed as:
wherein:represents hydrogen partial pressure, MPa; LHSV denotes liquid volumetric flow rate, h -1 The method comprises the steps of carrying out a first treatment on the surface of the a represents a reaction space velocity correction coefficient; b represents a pressure correction coefficient; beta represents a correction coefficient of catalyst life; y is S 、y N The grading proportion of the catalyst in the HDS reaction section of the coal tar desulfurization reaction kinetic model and the HDN reaction section of the coal tar denitrification reaction kinetic model is respectively; k (k) 1,S ，k 2,S Respectively representing the main reaction rate and the side reaction rate of an HDS reaction section of a coal tar desulfurization reaction kinetic model; k (k) 1,N ，k 2,N Respectively represent the denitrification reaction movement of the coal tarThe main reaction rate and the side reaction rate of the HDN reaction section of the mechanical model; t represents a reaction time; t is t c Shows half life time as denitrification catalyst; c (C) A0 Is the proportion of raw materials at the inlet of the desulfurization section reactor.
Preferably, in step 5), the residual of the test value and the calculated value is used as an objective function of the parameter estimation, and the expression of the objective function is:
wherein Y is ex Representing predicted values,%; y is Y real The experimental values are shown in% (wt.%).
Compared with the prior art, the invention has the following beneficial effects:
the invention discloses a method for modeling a low-temperature coal tar full-fraction hydrocracking lumped dynamic model, which establishes a lumped dynamic model for a low-temperature coal tar hydrocracking reaction process, and experiments prove that the error of the predicted results of an HDS coal tar desulfurization reaction dynamic model, an HDN coal tar denitrification reaction dynamic model and an HDO coal tar deoxidation reaction dynamic model is not more than 4% compared with the predicted results of the experiment results, and the error between the predicted results and the experiment measured values of a target product yield dynamic model is not more than 0.02%. The established kinetic model can well predict the properties of coal tar hydrogenation products under different processes and different operation periods, and can also provide a series of reliable presumption values for the change condition of the catalyst activity under long-period operation. In summary, the modeling method of the low-temperature coal tar full-fraction hydrocracking lumped dynamics model disclosed by the invention has the following advantages:
1. the kinetic model can be suitable for predicting the product properties under various conditions.
2. The model can accurately predict the sulfur, nitrogen and oxygen contents of hydrogenation products under different airspeeds, pressures and temperature components and the yield of target products.
3. Compared with the predicted results of the HDS dynamic model, the HDN dynamic model and the HDO dynamic model, the error of the predicted result of the target product yield and the error of the experimental value are not more than 4 percent. The model can well predict the properties of coal tar hydrogenation products under different processes and different running periods.
4. The model can provide a series of more reliable presumption values for the change of the catalyst activity under long-period operation.
Drawings
FIG. 1 is an ion flow chromatogram of a raw coal tar of the present invention;
FIG. 2 is a graph showing the relationship between the temperature and the sulfur-nitrogen-oxygen content in the product and the yield of the target product;
FIG. 3 is a graph showing the relationship between the pressure and the sulfur-nitrogen-oxygen content in the product and the yield of the target product;
FIG. 4 is a graph showing the relationship between space velocity and sulfur-nitrogen-oxygen content in the product and the yield of the target product;
FIG. 5 is a schematic diagram of the overall reaction network for hydrocracking according to the present invention.
Detailed Description
In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The invention is described in further detail below with reference to the attached drawing figures:
the invention relates to a modeling method of a low-temperature coal tar full-fraction hydrocracking lumped dynamic model, which comprises the following specific processes:
step 1, performing virtual lumped component division on hydrocracking reaction:
the invention performs lumped division from two angles of raw oil and generated oil; dividing raw oil by sulfur-containing, nitrogen-containing and oxygen-containing compounds after hydrocracking; the resulting oil is divided by the sulfur content and nitrogen content of the hydrocracked product. The lumped divisions of the low temperature coal tar hydrocracking lumped kinetic model are as follows: lumped 1-sulfur compounds; lumped 2-nitrogen containing compounds; lumped 3-oxygenates wherein lumped 1, 2, 3 are all compounds in the hydrocracked product.
Step 2, the hydrocracking lumped kinetic model basically assumes:
(1) The reactor was operated as a continuous steady state operation;
(2) The reactor is an adiabatic reactor;
(3) The process of producing the target product and the byproduct by coal tar hydrogenation accords with an ideal parallel reaction form and accords with a 1-level reaction dynamics model;
(4) The raw materials are uniformly distributed on the surface of the catalyst;
(5) The gasification and condensation of raw materials do not exist in the reactor;
(6) The hydrogenation reaction only takes place in the solid phase;
(7) The reactor has no axial back mixing and uniform concentration of radial reactants;
(8) The reaction between the components is irreversible.
Step 3, constructing a hydrocracking total reaction network;
the hydrocracking reaction network finally obtains a total reaction lumped dynamic network diagram through reasonable assumption and simplified treatment; FIG. 5 is a schematic diagram of the overall reaction network for hydrocracking according to the present invention; wherein Lump1 represents coal tar feedstock; lump2 represents a sulfur-containing compound; lump3 represents a nitrogen-containing compound; lump4 represents an oxygenate, i.e., the compositional partitioning of lumped dynamics includes lumped 1-sulfur compounds, lumped 2-nitrogen compounds, lumped 3-oxygenates; wherein, the lumped 1, the lumped 2 and the lumped 3 are all compounds in the hydrocracking reaction product.
Step 4, establishing a hydrocracking lumped reaction dynamics model;
(1) Sulfur-containing compounds in coal tar are generally classified into non-thiophenes and thiophenes according to their molecular structure. Wherein, the non-thiophene sulfur-containing compound does not belong to heterocyclic compounds, and the S-C bond energy in the molecular structure is lower, so that sulfur elements in the substances are easier to remove.
All sulfur-containing compounds in coal tar are divided into a whole to consider the reaction kinetic form, and the conversion degree is reacted by reducing the sulfuration content in the coal tar. The HDS kinetic model of coal tar can be initially expressed as:
in the method, in the process of the invention,
W S representing the mass fraction of sulfur in coal tar;
k represents the reaction rate of the coal tar HDS reaction;
n s the reaction progression is shown.
Further, in the above step 4, the above formula can be expressed as follows in terms of two cases of reaction series=1 and +.1:
in the method, in the process of the invention,
W inlet,s and W is outlet,s Respectively representing the mass fractions of sulfur in the feed coal tar and the discharge coal tar.
Further discussion n s Not equal to 1 and n s Two cases =1.
(1) When n is s Not equal to 1, in step 4 above, the coal tar HDS kinetic model can be expressed in the form:
in the method, in the process of the invention,
represents hydrogen partial pressure, MPa;
LHSV denotes liquid volumetric flow rate, h -1 ；
a represents a reaction space velocity correction coefficient;
b represents a pressure correction coefficient;
k 0 a pre-finger factor representing the Arrhenius equation;
E a represents the apparent activation energy of the reaction, J/moL;
t represents the reaction temperature, K;
r represents a pervasive factor, 8.314J/moL.
The preparation method is simplified and the product is obtained,
further, in the above step 4, the influence of the catalyst deactivation factor on hydrodesulfurization is considered. Assuming that the catalyst inactive kinetic form conforms to the time-varying inactive form, the kinetic model reduces to the following form:
in the method, in the process of the invention,
a represents the activity of the catalyst;
t represents the run time of the reaction apparatus;
t c,s shows half life time as a desulfurization catalyst;
β S is a correction factor for catalyst life in coal tar HDS reactions.
The preparation method is simplified and the product is obtained,
different hydrogenation catalysts often have other functions in addition to the main functions in the hydrogenation reaction process. Further, in the above step 4, considering the grading effect of the catalyst types, the coal tar desulfurization reaction kinetic model can be expressed as:
wherein:
y i the grading proportion of different catalysts in the desulfurization reaction is shown;
E a,si the reaction activation energy corresponding to different catalysts in the desulfurization reaction is shown;
k 0,si indicating the pre-finger factors of the Arrhenius equation for different catalysts in the desulfurization reaction.
(2) When n is s When=1, in step 4 above, the coal tar HDS kinetic model can be expressed as follows:
according to the Arrhenius equation:
the preparation method is simplified and the product is obtained,
further, in the above step 4, the influence of the catalyst deactivation factor on hydrodesulfurization is considered. Assuming that the catalyst inactive kinetic form conforms to the time-varying inactive form, the kinetic model reduces to the following form:
the preparation method is simplified and the product is obtained,
different hydrogenation catalysts often have other functions in addition to the main functions in the hydrogenation reaction process. Further, in the above step 4, considering the grading effect of the catalyst types, the coal tar desulfurization reaction kinetic model can be expressed as:
finally, the preparation method of the composite material is obtained,
(2) The nitrogen-containing compound is the most difficult heteroatom-removing compound in coal tar, and the main reason is that nitrogen atoms in the molecular structure of the heterocyclic nitrogen-containing compound often contain carbon-nitrogen double bonds, so that the substances are very stable, and further heteroatom-removing reaction can usually be carried out after the double bonds are opened through hydrogenation saturation reaction.
Further, in the above step 4, all nitrogen-containing compounds in the coal tar are divided into one body to consider the reaction kinetic form thereof, and the degree of conversion thereof is reacted with the reduction of the nitriding content in the coal tar. The HDN kinetic model of coal tar can be initially expressed as:
in the method, in the process of the invention,
W N representing the mass fraction of nitrogen in the coal tar;
k represents the reaction rate of the coal tar HDN reaction;
n s the reaction progression is shown.
Further, in the above step 4, the above formula can be expressed as follows in terms of two cases of reaction series=1 and +.1:
in the method, in the process of the invention,
W inlet,N and W is outlet,N Respectively representing the mass fractions of nitrogen in the feed coal tar and the discharge coal tar.
Further discussion n s Not equal to 1 and n s Two cases =1.
(1) When n is s Not equal to 1, in the above step 4, the coal tar HDN kinetic model may be expressed as follows:
in the method, in the process of the invention,
represents hydrogen partial pressure, MPa;
LHSV denotes liquid volumetric flow rate, h -1 ；
a N Representing a reaction pressure correction coefficient;
b N representing an airspeed correction factor;
k 0,N a pre-finger factor representing the Arrhenius equation;
E a,N represents the apparent activation energy of the reaction, J/moL;
t represents the reaction temperature, K;
r represents a pervasive factor, 8.314J/moL.
Further, in the above step 4, the influence of the catalyst deactivation factor on hydrodenitrogenation is considered. Assuming that the catalyst inactive kinetic form conforms to the time-varying inactive form, the kinetic model reduces to the following form:
in the method, in the process of the invention,
a represents the activity of the catalyst;
t represents the run time of the reaction apparatus;
t c,N shows half life time as a catalyst in denitrification reaction;
β N is a correction coefficient of catalyst life in the HDN reaction of coal tar.
The preparation method is simplified and the product is obtained,
different hydrogenation catalysts often have other functions in addition to the main functions in the hydrogenation reaction process. Further, in the above step 4, considering the grading effect of the catalyst types, the coal tar denitrification reaction kinetic model can be expressed as:
in the method, in the process of the invention,
y i the grading proportion of different catalysts in the denitrification reaction is shown;
E a,Ni the reaction activation energy corresponding to different catalysts in the denitrification reaction is represented;
k 0,Ni indicating the pre-pointing factors of Arrhenius equations corresponding to different catalysts of the denitrification reaction.
(2) When n is s When=1, in the above step 4, the coal tar HDN kinetic model can be expressed as follows:
further, in the above step 4, the influence of the catalyst deactivation factor on hydrodenitrogenation is considered. Assuming that the catalyst inactive kinetic form conforms to the time-varying inactive form, the kinetic model reduces to the following form:
the preparation method is simplified and the product is obtained,
different hydrogenation catalysts often have other functions in addition to the main functions in the hydrogenation reaction process. Further, in the above step 4, considering the grading effect of the catalyst types, the coal tar denitrification reaction kinetic model can be expressed as:
finally, the preparation method of the composite material is obtained,
(3) The oxygenate content in the coal tar is very high and in some coal tar may even exceed the oxygenate content of the hydrocarbon compounds. Although the content of the oxygen-containing compound is huge, the oxygen-containing compound is easier to remove along with the increase of the hydrogenation reaction depth. Among the oxygenates of coal tar, alcohols, carboxylic acids and ketones are relatively susceptible to hydrodeoxygenation reactions to produce water and the corresponding hydrocarbonaceous materials.
Further, in the above step 4, all the oxygenates in the coal tar are divided into one body to take into consideration the reaction kinetic form thereof, and the conversion degree thereof is reacted with the reduction of the oxidation content in the coal tar. The HDO kinetic model of coal tar can be initially expressed as:
in the method, in the process of the invention,
W O representing the mass fraction of oxygen in the coal tar;
k represents the reaction rate of the coal tar HDO reaction;
n s the reaction progression is shown.
Further, in the above step 4, the above formula can be expressed as follows in terms of two cases of reaction series=1 and +.1:
in the method, in the process of the invention,
W inlet,O and W is outlet,O Respectively representing the mass fractions of oxygen in the feed coal tar and the discharge coal tar.
Further discussion n s Not equal to 1 and n s Two cases =1.
(1) When n is s Not equal to 1, in the above step 4, the coal tar HDO kinetic model may be expressed as follows:
in the method, in the process of the invention,
represents hydrogen partial pressure, MPa;
LHSV denotes liquid volumetric flow rate, h -1 ；
a O Representing a reaction pressure correction coefficient;
b O representing an airspeed correction factor;
k 0,O a pre-finger factor representing the Arrhenius equation;
E a,O represents the apparent activation energy of the reaction, J/moL;
t represents the reaction temperature, K;
r represents a pervasive factor, 8.314J/moL.
Further, in the above step 4, the influence of the catalyst deactivation factor on hydrodeoxygenation is considered. Assuming that the catalyst inactive kinetic form conforms to the time-varying inactive form, the kinetic model reduces to the following form:
in the method, in the process of the invention,
a represents the activity of the catalyst;
t represents the run time of the reaction apparatus;
t c,O indicating the half life time of the catalyst in the deoxygenation reaction;
β O is a correction coefficient of catalyst life in the HDO reaction of coal tar.
The preparation method is simplified and the product is obtained,
different hydrogenation catalysts often have other functions in addition to the main functions in the hydrogenation reaction process. Further, in the above step 4, considering the grading effect of the catalyst species, the coal tar deoxygenation reaction kinetic model may be expressed as:
in the method, in the process of the invention,
y i the grading proportion of different catalysts in the deoxidation reaction is shown;
E a,Oi the reaction activation energy corresponding to different catalysts in the deoxidation reaction is shown;
k 0,Oi indicating the pre-pointing factors of the Arrhenius equation for the different catalysts in the deoxygenation reaction.
(2) When n is s When=1, in the above step 4, the coal tar HDO kinetic model can be expressed as follows:
further, in the above step 4, the influence of the catalyst deactivation factor on hydrodeoxygenation is considered. Assuming that the catalyst inactive kinetic form conforms to the time-varying inactive form, the kinetic model reduces to the following form:
the preparation method is simplified and the product is obtained,
different hydrogenation catalysts often have other functions in addition to the main functions in the hydrogenation reaction process. Further, in the above step 4, considering the grading effect of the catalyst species, the coal tar deoxygenation reaction kinetic model may be expressed as:
finally, the preparation method of the composite material is obtained,
(4) Coal tar is converted into gasoline and diesel oil in the hydrofining process, which is a main target product, and the generation of byproducts such as pyrolysis gas, water and the like is unavoidable. The gradation ratio of HDS to HDN catalyst is defined as y S And y is N 。
In the step 4, in the desulfurization section reactor, the kinetic models of the raw material, the target product and the byproducts have the following expression forms:
C A,S ＝C A0 exp[-y s (k 1,s +k 2,s )(LHSV) a ]
in the method, in the process of the invention,
y S 、y N the gradation ratio of the HDS catalyst and the HDN catalyst is respectively;
k 1,S 、k 2,S respectively representing the main reaction rate and the side reaction rate in the HDS reaction section reactor;
C A0 the ratio of the raw materials at the inlet of the desulfurization section reactor;
C A,S 、C B,S 、C C,S the content of the raw material, the main product and the by-product at the outlet of the HDS reactor are respectively shown.
Further, in the step 4, the main product dynamics model has the following expression form in the denitrification reactor:
C A,N ＝C A0 exp[-y s (k 1,s +k 2,s )(LHSV) a ]exp[-y N (k 1,N +k 2,N )(LHSV) a ]
further, in step 4, since both stages of the reactor produce product, the reactor produces a main product yield C B ＝C B,S +C B,N . Because the temperature, pressure, and the run time of the catalyst device all affect the reaction during the reaction. Considering the effect of the hydrogen partial pressure, the above formula can be expressed as:
k in the formula 1,S ,k 2,S ,k 1,N ,k 2,N Can be expressed in the following form:
in the method, in the process of the invention,
T S ，T N the reaction temperatures of the HDS stage reactor and the HDN stage reactor are respectively shown;
k 1,S ，k 2,S the main reaction rate and the side reaction rate in the HDS segment reactor are respectively shown;
k 1,N ，k 2,N respectively representing the main reaction rate and the side reaction rate in the HDN segment reactor;
t represents the run time of the reaction apparatus;
t c shows half life time as denitrification catalyst;
y S 、y N the gradation ratio of the HDS catalyst and the HDN catalyst is respectively;
C A0 the ratio of the raw materials at the inlet of the desulfurization section reactor;
E a,S1 ,E a,S2 representing the reaction activation energy in the first and second stages of the HDS reactor, respectively;
E a,N1 ,E a,N2 the reaction activation energy in the first section and the second section of the HDN reactor are respectively shown;
k 0,S1 ,k 0,S2 representing the reaction activation energy in the first and second stages of the HDS reactor, respectively;
k 0,N1 ,k 0,N2 the reaction activation energy in the first and second stages of the HDN reactor are shown, respectively.
Step 5, determining kinetic parameters of each reaction and determining an objective function;
in the invention, the model fitting solving method is an LM algorithm in MATLAB software, the parameters corresponding to the dynamic model are solved by adopting the principle of a damping least square method, the residual error of a test value and a calculated value is adopted as an objective function of parameter estimation, and the expression of the objective function is as follows:
in the method, in the process of the invention,
Y ex representing predicted values,%;
Y real experimental values,%;
step 6, model verification;
and the extrapolation performance and the prediction capability of the established low-temperature coal tar hydrocracking kinetic model are verified through experimental comparison.
The above model will be described by way of specific examples.
Example 1
(1) The invention takes 360 ℃ front distillate oil of coal tar obtained by a reduced pressure distillation mode as a raw material, and the coal tar is a byproduct obtained by low-temperature pyrolysis of the Shanxi long flame coal at 550 ℃. The catalyst used in this experiment was Ni-Mo-P 0.8 /γ-Al 2 O 3 A catalyst. Before the coal tar hydrogenation experiment starts, the catalyst is vulcanized by wet vulcanization, and when the presulfiding is finished, the reaction condition is regulated to the reference process condition: the reaction temperature is 360 ℃; the reaction pressure is 10MPa; space velocity of 0.5h -1 The method comprises the steps of carrying out a first treatment on the surface of the The hydrogen-oil ratio is 1600:1.
The relevant properties of the raw material coal tar used in the experiment are shown in table 1 and fig. 1, and the relevant physical properties and composition distribution of the raw material coal tar of the invention can be known.
Table 1 basic properties of raw coal tar
(2) The low-temperature coal tar lumped dynamics model is divided from two angles of raw oil and generated oil; dividing raw oil by sulfur-containing, nitrogen-containing and oxygen-containing compounds after hydrocracking; the resulting oil is divided by the sulfur content and nitrogen content of the hydrocracked product. The lumped divisions of the low temperature coal tar hydrocracking lumped kinetic model are as follows: lumped 1-sulfur compounds; lumped 2-nitrogen containing compounds; lumped 3-oxygenates wherein lumped 1, 2, 3 are all compounds in the hydrocracked product.
(3) Model experimental data
The experiment examines the influence of hydrogen partial pressure, airspeed and cracking bed temperature on the hydrocracking reaction network of the low-temperature coal tar. The experiment adopted a hydrogen-oil ratio of 1600:1, and during the running process of the device, 27 groups of effective data were collected in total, and experimental conditions and results are shown in Table 2.
Table 2 data of long period run experiments for hydrofining of coal tar
(4) Model parameter fitting
According to the reaction temperature of 360 ℃, the reaction pressure of 10MPa and the reaction space velocity of 0.3h -1 Data obtained at a hydrogen oil volume ratio of 1600:1. The LM method is used for fitting each kinetic parameter, and the parameters of the desulfurization kinetic model, the denitrification kinetic model and the deoxidization kinetic model are calculated, and the parameters of the target product yield model are shown in Table 3.
TABLE 3 desulfurization reaction kinetic model parameters
(5) And (5) model verification.
And the extrapolation performance and the prediction capability of the established low-temperature coal tar hydrocracking kinetic model are verified through experimental comparison.
Five experimental results were collected after 1176 hours of operation of the device to verify the product properties deduced from the established kinetic model, and the verification results are shown in table 4. The predicted results of the HDS dynamics model, the HDN dynamics model and the HDO dynamics model are not more than 4% in comparison with the experimental results, and the error between the predicted result of the yield dynamics of the target product and the experimental measurement value is not more than 0.02%. The established kinetic model can be used for well predicting the properties of coal tar hydrogenation products under different processes and different running periods.
TABLE 4 comparison of predicted and experimental results under different reaction conditions
a: the condition of experiment 1 is 13MPa, and the airspeed is 0.3h -1 The denitrification section reaction temperature is 633K, and the operation time is 1200h;
the condition of experiment 2 is 15MPa, airspeed is 0.3h -1 The denitrification section reaction temperature is 633K, and the operation time is 1224h;
the condition of experiment 3 is 13MPa, and the airspeed is 0.4h -1 The denitrification section reaction temperature is 633K, and the operation time is 1248 hours;
experiment 4 has a condition of 13MPa and a space velocity of 0.3h -1 The denitrification section reaction temperature 653K and the operation time 1272h;
experiment 5 has 13MPa and airspeed of 0.3h -1 The denitrification section reaction temperature is 633K, and the operation time is 1296 hours.
The law of change of the product property along with the increase of the denitrification section reaction temperature from 613K to 653K is shown in figure 2. The trend of the product properties as the reaction pressure increased from 11MPa to 15MPa is shown in FIG. 3.
With the increase of the reaction temperature, the contents of sulfur, nitrogen and oxygen in the coal tar hydrocracking product are gradually reduced, and the oxygen content is obviously reduced compared with the contents of sulfur and nitrogen, which indicates that the high temperature is favorable for hydrodeoxygenation. When the reaction temperature of the HDN section is higher than about 631K, the sulfur content in the product is lower than the nitrogen content, which shows that the promotion effect of increasing the reaction temperature on increasing the HDN of the coal tar is more obvious than the promotion effect on HDS. In the pressure range of 11-15 MPa, the improvement of the reaction pressure has positive significance on the reduction of the sulfur and nitrogen contents of the product and the improvement of the yield of the target product, and particularly has obvious deoxidizing effect.
Product properties with the reaction space velocity from 0.2h -1 Growing to 0.4h -1 The trend of the change in (c) is shown in fig. 4.
Within this space velocity range, a decrease in space velocity has positive implications for a decrease in product sulfur nitrogen content and an increase in target product yield. While at low airspeeds (less than about 0.3 h) -1 ) The reduction of the space velocity has less influence on the yield of the target product of the product, and the oxygen content in the product is the highest, and then the sulfur content and the nitrogen content are the highest, while the reduction of the space velocity in the higher space velocity range has more influence on the yield of the target product, and the oxygen content in the product is the highest, and the nitrogen content and the sulfur content are the second highest.
(6) Model analysis
Influence of temperature and pressure
The improvement of the denitrification section temperature has positive significance on the reduction of the sulfur-nitrogen-oxygen content of the product and the improvement of the yield of the target product along with the change rule range of the denitrification section reaction temperature from 613K to 653K. When the reaction temperature of the HDN section is higher than about 631K, the sulfur content in the product is lower than the nitrogen content, which shows that the promotion effect of improving the HDN of the coal tar by improving the reaction temperature is more obvious than the promotion effect of HDS; the oxygen content is obviously higher than the sulfur and nitrogen content, which indicates that the improvement of the reaction temperature is more favorable for the hydrodeoxygenation reaction. The product property is in the range of the change trend of the reaction pressure from 11MPa to 15MPa, and the improvement of the reaction pressure has positive significance on the reduction of the sulfur, nitrogen and oxygen contents of the product and the improvement of the yield of the target product. The increase of the pressure can increase the hydrogen amount in the reactor on one hand and promote hydrogen molecules to enter the oil phase on the other hand, so that the increase of the reaction pressure has positive effects on HDS, HDN, HDO in the coal tar hydrogenation process and coal tar lightening. From the figure it can be seen that the effect of pressure on coal tar HDS, HDN and HDO is almost simultaneous, since both reactions require the participation of hydrogen and increasing the pressure has the same effect on increasing both reactions.
Influence of airspeed
Product properties with the reaction space velocity from 0.2h -1 Growing to 0.4h -1 In the range of the variation trend of (2), the reduction of the airspeed has positive significance on the reduction of the sulfur, nitrogen and oxygen content of the product and the improvement of the yield of the target product. While at low airspeeds (less than about 0.3 h) -1 ) The reduction of the space velocity has less influence on the yield of the target product of the product, and the sulfur content of the product is higher than the nitrogen content, while the reduction of the space velocity in the higher space velocity range has more influence on the yield of the target product, and meanwhile, the oxygen content in the product is highest, and the sulfur content and the nitrogen content are inferior.
Influence of yield of target product
The modeling method of the low-temperature coal tar full-fraction hydrocracking lumped dynamic model disclosed by the invention can be suitable for predicting the product properties under various conditions, has a certain guiding significance on site based on the dynamic parameters calculated by the 1200h experimental result in the embodiment, and has a certain reference value by utilizing the dynamic model and the experimental result calculated by the parameters when predicting the product properties generated under the process parameters deviating from the too large experimental conditions in the research. The most valuable predicted value provided by the dynamic model is the change of the product property under the long-period running of the device. With a reference condition: the reaction temperature of the desulfurization section is 320 ℃, the denitrification reaction temperature is 380 ℃ and the space velocity is 0.3h -1 For example, the reaction pressure is 13MPa, the yield of the target product is reduced by 7.22% after the catalyst system is used for two years, and the sulfur content, the nitrogen content and the oxygen content of the product are respectively increased by 118%, 176% and 198%.
In the invention, distillate oil with the temperature of coal tar less than 360 ℃ is used as a raw material, and hydrofining experiments are carried out on four-pipe serial fixed bed hydrogenation reactors. Based on the experimental results of 1200h, a set of four lumped dynamic models is established, and the following conclusions are obtained through researches:
(1) According to the comparison of the experimental result and the calculation result, the error of the dynamic model for predicting the S, N, O content of the product is less than 4%, and the error for predicting the yield of the target product is less than 0.04%.
(2) The four lumped dynamic models can well predict the influence of the process conditions on the change of the product yield and the property, and can also provide a series of reliable presumption values for the change of the catalyst activity under long-period operation.
(3) Through dynamic calculation, compared with the initial operation period after the device is operated continuously for one and a half years, the fuel oil yield is reduced by about 5.30%, the sulfur content is improved by about 75.49%, the nitrogen content is improved by about 111.67%, and the oxygen content is improved by about 132.5%.
In summary, according to the experimental data of 1200 hours completed on the coal tar hydrogenation pilot plant, the invention carries out kinetic study on coal tar hydrofining on a four-tube series fixed bed hydrogenation device. The established dynamic model considers the attenuation of the catalyst activity and the influence of the technological conditions such as temperature, pressure, airspeed and the like on the product property.
The hydrofining process has four main targets of definite desulfurization, denitrification, deoxidation and oil product lightening, so that the compounds in the coal tar can be simply and intensively divided during the kinetic study. By establishing a set of HDS dynamic model, HDN dynamic model, HDO dynamic model and fuel oil yield dynamic model in the coal tar hydrogenation process, the sulfur, nitrogen and oxygen contents and the yield of the target product of the hydrogenation product under different airspeed, pressure and temperature parts are accurately predicted, and the change of the product property under long-period operation can be predicted.
The above is only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited by this, and any modification made on the basis of the technical scheme according to the technical idea of the present invention falls within the protection scope of the claims of the present invention.
Claims (6)
1. The modeling method of the low-temperature coal tar full-fraction hydrocracking lumped kinetic model is characterized by comprising the following steps of:
1) Carrying out lumped dynamic component division on the hydrocracking reaction;
2) Establishing a lumped dynamics model basic assumption;
3) Constructing a hydrocracking total reaction network diagram;
4) Establishing a hydrocracking lumped dynamics model;
5) Determining kinetic parameters of each reaction and determining an objective function;
6) And (3) verifying a model: the extrapolation performance and the prediction capability of the established low-temperature coal tar hydrocracking dynamic model are verified through experimental comparison;
the hydrocracking reaction in the step 1) comprises a raw oil hydrocracking reaction and a produced oil hydrocracking reaction; the hydrocracking reaction of the raw oil is divided by the sulfur, nitrogen and oxygen compounds after the reaction, and the hydrocracking reaction of the generated oil is divided by the sulfur content and the nitrogen content in the product;
wherein the component division of the lumped dynamics comprises lumped 1-sulfur compounds, lumped 2-nitrogen compounds, lumped 3-oxygen compounds; wherein, the lumped 1, the lumped 2 and the lumped 3 are all compounds in the hydrocracking reaction product;
in the step 4), all sulfur-containing compounds in the coal tar are divided into a whole for reaction kinetics modeling, and the conversion degree of the coal tar hydrocracking reaction is reacted by the reduction of the sulfur content in the coal tar; namely, the coal tar desulfurization reaction kinetic model HDS is preliminarily expressed as:
in which W is S Representing the mass fraction of sulfur in coal tar; k represents coal tar desulfurization reaction kinetic modelReaction rate of HDS; n is n s Representing the reaction progression;
in step 4), when the reaction number is n s Not equal to 1 or the reaction series n s At=1, considering the catalyst deactivation factor and the grading effect of the catalyst species, the coal tar desulfurization reaction kinetic model HDS is expressed as:
wherein: w (W) inlet,s And W is outlet,s Respectively representing the mass fractions of sulfur in the feed coal tar and the discharge coal tar;represents hydrogen partial pressure, MPa; LHSV denotes liquid volumetric flow rate, h -1 ；a s Representing a reaction space velocity correction coefficient; b s Representing a pressure correction coefficient; t represents the reaction temperature of desulfurization reaction, K; r represents a pervasive factor, 8.314J/moL; t represents the operation time of the desulfurization reaction device; t is t c,s Shows half life time as a desulfurization catalyst; beta S The correction coefficient of the catalyst life in the HDS reaction of the coal tar; y is i The grading proportion of different catalysts in the desulfurization reaction is shown; e (E) a,si The reaction activation energy corresponding to different catalysts in the desulfurization reaction is shown; k (k) 0,si Indicating the pre-finger factors of Arrhenius equations corresponding to different catalysts in the desulfurization reaction;
in the step 4), coal tar is converted into target products of gasoline, diesel and byproducts in the refining process of the hydrocracking reaction, and the grading proportion and the hydrogen partial pressure of the catalyst are considered, and the reaction of the target products and the byproducts accords with a 1-level reaction dynamics model, so that the target product dynamics model is expressed as:
wherein:represents hydrogen partial pressure, MPa; LHSV denotes liquid volumetric flow rate, h -1 The method comprises the steps of carrying out a first treatment on the surface of the a represents a reaction space velocity correction coefficient; b represents a pressure correction coefficient; beta represents a correction coefficient of catalyst life; y is S 、y N The grading proportion of the catalyst in the HDS reaction section of the coal tar desulfurization reaction kinetic model and the HDN reaction section of the coal tar denitrification reaction kinetic model is respectively; k (k) 1,S ，k 2,S Respectively representing the main reaction rate and the side reaction rate of an HDS reaction section of a coal tar desulfurization reaction kinetic model; k (k) 1,N ，k 2,N Respectively representing the main reaction rate and the side reaction rate of the HDN reaction section of the coal tar denitrification reaction kinetic model; t represents a reaction time; t is t c Shows half life time as denitrification catalyst; c (C) A0 Is the proportion of raw materials at the inlet of the desulfurization section reactor.
2. The method for modeling the lumped kinetic model of the full-fraction hydrocracking of the low-temperature coal tar according to claim 1, wherein in the step 4), all nitrogen-containing compounds in the coal tar are divided into a whole for reaction kinetic modeling, and the conversion degree of the hydrocracking reaction of the coal tar is reflected by the reduction of the nitriding content in the coal tar; namely, the coal tar denitrification reaction kinetic model HDN is preliminarily expressed as:
in which W is N Representing the mass fraction of nitrogen in the coal tar; k represents the reaction rate of the coal tar denitrification reaction kinetic model HDN; n is n s The reaction progression is shown.
3. The method for modeling the lumped kinetic model of the whole fraction hydrocracking of the low-temperature coal tar according to claim 2, wherein in the step 4), when the reaction progression n is s Not equal to 1 or the reaction series n s When=1, consider the catalyst deactivation factor and the stage of the catalyst typeThe coordination, coal tar denitrification reaction kinetics model HDN is expressed as:
wherein: w (W) inlet,N And W is outlet,N Respectively representing the mass fractions of nitrogen in the feed coal tar and the discharge coal tar; p is p H2 Represents hydrogen partial pressure, MPa; LHSV denotes liquid volumetric flow rate, h -1 ；a N Representing a reaction space velocity correction coefficient; b N Representing a pressure correction coefficient; t represents the reaction temperature of denitrification reaction, K; r represents a pervasive factor, 8.314J/moL; t represents the operation time of the denitrification reaction apparatus; t is t c,N Shows half life time as a catalyst in denitrification reaction; beta N The correction coefficient of the catalyst life in the HDN reaction of the coal tar; y is i Representing the grading proportion of different catalysts in the denitrification reaction; e (E) a,Ni The reaction activation energy corresponding to different catalysts in the denitrification reaction is represented; k (k) 0,Ni Indicating the pre-pointing factors of the Arrhenius equation for different catalysts in the denitrification reaction.
4. The method for modeling the lumped kinetic model of the full-fraction hydrocracking of the low-temperature coal tar according to claim 1, wherein in the step 4), all oxygen-containing compounds in the coal tar are divided into a whole for reaction kinetic modeling, and the conversion degree of the hydrocracking reaction of the coal tar is reacted by the reduction of the oxidation content in the coal tar; namely, the coal tar deoxidization reaction kinetic model HDO is preliminarily expressed as:
in which W is O Representing the mass fraction of oxygen in the coal tar; k represents the reaction rate of the coal tar deoxidation reaction kinetic model HDO; n is n s The reaction progression is shown.
5. According toThe modeling method of the lumped kinetic model for the full-fraction hydrocracking of the low-temperature coal tar as claimed in claim 4, wherein in the step 4), when the reaction level number n is s Not equal to 1 or the reaction series n s At=1, considering the catalyst deactivation factor and the grading effect of the catalyst species, the coal tar deoxygenation reaction kinetic model HDO is expressed as:
wherein: w (W) inlet,O And W is outlet,O Respectively representing the mass fractions of oxygen in the feed coal tar and the discharge coal tar; p is p H2 Represents hydrogen partial pressure, MPa; LHSV denotes liquid volumetric flow rate, h -1 ；a O Representing a reaction space velocity correction coefficient; b O Representing a pressure correction coefficient; t represents the reaction temperature of the deoxidation reaction, K; r represents a pervasive factor, 8.314J/moL; t represents the operation time of the deoxidizing reaction apparatus; t is t c,O Indicating the half life time of the catalyst in the deoxygenation reaction; beta O The correction coefficient of the catalyst life in the HDO reaction of the coal tar; y is i The grading proportion of different catalysts in the deoxidation reaction is shown; e (E) a,Oi The reaction activation energy corresponding to different catalysts in the deoxidation reaction is shown; k (k) 0,Oi Indicating the pre-pointing factors of the Arrhenius equation for the different catalysts in the deoxygenation reaction.
6. The method for modeling a lumped kinetic model of low-temperature coal tar full-fraction hydrocracking as claimed in claim 1, wherein in step 5), a residual error of a test value and a calculated value is adopted as an objective function of parameter estimation, and an expression of the objective function is as follows:
wherein Y is ex Representing predicted values,%; y is Y real The experimental values are shown in% (wt.%).
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