JPWO2010087135A1 - Method of operating middle distillate hydrotreating reactor and middle distillate hydrotreating reactor - Google Patents

Abstract

Method for operating a middle distillate hydrotreating reactor that hydrotreats and hydroisomerizes middle distillate containing components in the boiling range corresponding to diesel oil among FT synthesized hydrocarbons synthesized by Fischer-Tropsch synthesis reaction A step of bringing the middle distillate into contact with a catalyst to hydrotreat and hydroisomerize to obtain a hydrofinished middle distillate, and the hydrogen flowing out from the middle distillate hydrotreating reactor. Measuring the cloud point of the refined middle distillate, and controlling the operating conditions of the middle distillate hydrotreating reactor so that the cloud point becomes a predetermined target value. Operation method of middle distillate hydrotreating reactor.

Description

The present invention relates to a middle distillate hydrotreating reactor that hydrotreats and hydroisomerizes a middle distillate containing components in a boiling range corresponding to light oil among hydrocarbon compounds synthesized by a Fischer-Tropsch synthesis reaction. And a middle distillate hydrotreating reactor.
This application claims priority based on Japanese Patent Application No. 2009-020855 for which it applied in Japan on January 30, 2009, and uses the content here.

In recent years, as one of the methods for synthesizing liquid fuel from natural gas, the natural gas is reformed to produce a synthetic gas mainly composed of carbon monoxide gas (CO) and hydrogen gas (H ₂ ), A hydrocarbon compound (hereinafter referred to as “FT synthetic hydrocarbon”) is synthesized by the Fischer-Tropsch synthesis reaction (hereinafter referred to as “FT synthesis reaction”) using this synthesis gas as a raw material gas. GTL (Gas To Liquids) technology has been developed to produce liquid fuel products such as naphtha (crude gasoline), kerosene, light oil (diesel fuel oil) and wax by hydroprocessing and fractional distillation. .

Here, since the liquid fuel product using the above-mentioned FT synthetic hydrocarbon as a raw material has a high paraffin content and hardly contains a sulfur content, for example, as shown in Patent Document 1, attention is paid to an environmentally friendly fuel.
When this FT synthetic hydrocarbon is fractionated in a rectifying column, an intermediate fraction containing components in the boiling range corresponding to light oil is taken out from the center of the rectifying column. This middle distillate is used as a raw material for light oil. Further, a wax fraction having a large number of carbon atoms is taken out from the bottom of the rectifying column. This wax fraction can be used as a raw material for light oil by being lightened by hydrocracking.

  Here, the middle fraction of the above-mentioned FT synthetic hydrocarbon contains a large amount of normal paraffins, so the freezing point (solidification temperature) tends to increase. The low-temperature characteristics of light oil made from this middle fraction are the products. May not meet the required level. For this reason, the middle distillate distilled from the rectification column is used together with the conversion of oxygen-containing compounds such as olefins and alcohols by-produced in the FT synthesis reaction step to saturated hydrocarbons by hydrorefining. It is necessary to perform hydroisomerization to convert at least a part of normal paraffin to isoparaffin having a low freezing point.

JP 2004-323626 A

In the middle distillate hydrorefining step in which the middle distillate is hydrorefined and hydroisomerized, if the progress of hydroisomerization is insufficient, the resulting hydrofinished middle distillate will have a freezing point. A large amount of normal paraffin having a high content remains, and the low-temperature characteristics of light oil made from this middle distillate are not sufficiently improved. On the other hand, in the middle distillate hydrorefining process, when the hydroisomerization conditions are excessive, the hydrocarbons produced by the decomposition reaction are lightened and become unsuitable as a raw material for light oil, The yield of light oil as a product may be reduced.
For this reason, in order to obtain light oil (diesel fuel oil) from FT synthetic hydrocarbons, it is necessary to appropriately proceed with hydroisomerization in the middle distillate hydrotreating process.

  The present invention has been made in view of the above-described circumstances, and has advanced hydroisomerization in the hydrorefining step of the middle distillate of the FT synthesized hydrocarbon obtained by the FT synthesis reaction appropriately and has been stabilized. An object of the present invention is to provide a method for operating a middle distillate hydrotreating reactor and a middle distillate hydrotreating reactor capable of producing a hydrodistilled middle distillate having properties and obtaining high-quality gas oil. It is said.

In order to solve the above problems and achieve such an object, the present invention proposes the following means.
The method for operating the middle distillate hydrotreating reactor of the present invention comprises hydrotreating middle distillate containing components in the boiling range corresponding to light oil among FT synthesized hydrocarbons synthesized by Fischer-Tropsch synthesis reaction. A method for operating a middle distillate hydrorefining reactor to be hydroisomerized, wherein the middle distillate is brought into contact with a catalyst to hydrotreat and hydroisomerize to obtain a hydrofinished middle distillate Measuring the cloud point of the hydrorefined middle distillate flowing out of the middle distillate hydrotreating reactor, and the middle distillate hydrogen so that the cloud point becomes a predetermined target value. And a step of controlling the operating conditions of the chemical purification reactor.

In the operation method of the middle distillate hydrotreating reactor having the above-described configuration, the cloud point of the hydrofinished middle distillate flowing out from the middle distillate hydrotreating reactor is measured, and this cloud point is a predetermined target. Since the operating conditions of the middle distillate hydrotreating reactor are controlled so as to have a value, the cloud point of the hydrofinished middle distillate produced is stabilized. In addition, a cloud point is temperature at the time of clouding generate | occur | producing as a component (wax) with a high freezing point precipitates as a solid in liquid hydrocarbon (middle distillate). For example, as shown in JIS K 2269, the cloud point can be measured by cooling the sample liquid at a constant rate and measuring the liquid temperature when the sample liquid is clouded.
Here, when the amount of normal paraffin contained in the hydrorefined middle distillate produced is large, the cloud point of the hydrofinished middle distillate becomes high. On the other hand, when the amount of normal paraffin contained in the hydrofinished middle distillate is small, the cloud point of the hydrofinished middle distillate becomes low. That is, by measuring the cloud point of the hydrolysed middle distillate, it is possible to grasp the degree of progress of hydroisomerization in the middle distillate hydrotreating reactor.

Therefore, by measuring the cloud point of hydrorefined middle distillate and controlling the operating conditions of the middle distillate hydrorefining reactor based on this measured value, the hydroisomerization in the reactor is properly controlled. Thus, it is possible to produce a hydrorefined middle distillate having a stable property and to obtain a high quality light oil.
In light oil as diesel fuel oil, normal paraffin precipitates as a wax component when used under cold conditions, and the filter installed in the fuel oil supply system to the diesel engine may become clogged. There is. Therefore, for the purpose of preventing such problems, it is common to manage light oil products so as to have a cloud point of a certain value or less. However, conventionally, the use of the cloud point as an index for operation management has not been performed in a reactor for producing a middle distillate serving as a raw material for light oil.

In the operation method of the middle distillate hydrotreating reactor of the present invention, in the step of measuring the cloud point, the sample of the hydrofinished middle distillate collected is cooled at a cooling rate of 5.0 ° C./min. The cloud point may be measured by cooling under the condition of 15.0 ° C./min or less.
In this case, the cloud point can be measured in a short time by cooling at a cooling rate of 5.0 ° C./min or more and measuring the cloud point. As a result, the cloud point measurement result can be reflected in the control of the middle distillate hydrotreating reactor without a significant time delay after collection of the hydrofinished middle distillate sample. In addition, by measuring the cloud point by cooling at a cooling rate of 15.0 ° C./min or less, it becomes possible to measure the cloud point with high accuracy and appropriately control the middle distillate hydrotreating reactor. Can do.

Moreover, in the operation method of the middle distillate hydrotreating reactor of the present invention, in the step of measuring the cloud point, the collected sample is controlled while the cooling rate is controlled by an electronic cooling unit using a Peltier element. The cloud point may be measured after cooling.
In this case, it is possible to control the temperature of the hydrorefined middle distillate accurately and easily by cooling the middle distillate hydrorefined with an electronic cooling unit using a Peltier device. Thus, the cloud point can be accurately measured.

Further, in the method for operating a middle distillate hydrotreating reactor of the present invention, in the step of controlling the operating conditions of the middle distillate hydrotreating reactor, the middle distillate per unit time, the hydrogen partial pressure, the reaction temperature, At least one of the minute processing amounts may be controlled.
In this case, the degree of progress of hydroisomerization is controlled by controlling at least one of the hydrogen partial pressure, the reaction temperature, and the middle distillate throughput per unit time, which are the operating conditions of the middle distillate hydrotreating reactor. Can be adjusted. In addition, the middle distillate throughput per unit time can be represented by liquid space velocity (LHSV: Liquid hourly space velocity (h ⁻¹ )) as an oil flow rate to the middle distillate hydrotreating reactor.
For example, when the cloud point exceeds the upper limit of the operation management target range, conditions for increasing the hydrogen partial pressure and / or increasing the reaction temperature and / or reducing the middle distillate throughput (LHSV) per unit time As a result, the progress of hydroisomerization can be promoted, and the cloud point of the hydrolyzed middle distillate can be lowered. In addition, when the cloud point is below the lower limit of the operation management target range, the hydrogen partial pressure is reduced and / or the reaction temperature is lowered and / or the middle distillate throughput (LHSV) is increased. By setting it as the conditions to carry out, the progress of hydroisomerization can be suppressed and the cloud point of the middle distillate subjected to hydrorefining can be increased.

  The middle distillate hydrotreating reactor of the present invention is a hydrotreating and hydroisomerization process comprising a middle distillate containing components in the boiling range corresponding to light oil among FT synthesized hydrocarbons synthesized by Fischer-Tropsch synthesis reaction. A middle distillate hydrorefining reactor to be converted, a sampling unit for collecting a sample of the hydrofinished middle distillate to be produced, and a cloud point measuring unit for measuring a cloud point of the collected sample It has.

  According to the middle distillate hydrotreating reactor of this configuration, the cloud point of the hydrofinished middle distillate flowing out from the middle distillate hydrotreating reactor is quickly measured. Then, by controlling the operating conditions based on the results, the degree of progress of hydroisomerization can be adjusted appropriately, and the properties of the hydrorefined middle distillate produced can be stabilized. Thereby, the quality improvement of the light oil manufactured from this middle distillate can be aimed at.

  In the middle distillate hydrotreating reactor of the present invention, the sampling unit is connected to the cloud point measuring unit by a pipe, and the sample is automatically collected and transferred to the cloud point measuring unit. The cloud point measuring unit may automatically measure the cloud point of the transferred sample.

In the middle distillate hydrotreating reactor of the present invention, the cloud point measurement unit cools the collected sample at a cooling rate of 5.0 ° C./min to 15.0 ° C./min. May be provided with a cooling unit capable of.
In this case, since the sample can be cooled at the cooling rate, the cloud point can be measured quickly and accurately.

Furthermore, in the middle distillate hydrotreating reactor of the present invention, the sample provided in the cloud point measuring unit can be cooled at a cooling rate of 5.0 ° C./min to 15.0 ° C./min. The cooling unit may be an electronic cooling unit using a Peltier element.
In this case, the temperature control of the sample can be performed accurately and easily, and the cloud point can be measured with higher accuracy.

  According to this invention, in the hydrorefining step of the middle distillate of the FT synthesized hydrocarbon obtained by the FT synthesis reaction, the progress of hydroisomerization is properly controlled, and the hydrofinished intermediate having a stable property is obtained. A method for operating a middle distillate hydrotreating reactor and a middle distillate hydrotreating reactor capable of producing a distillate and capable of obtaining a high quality light oil (diesel fuel oil) can be provided.

FIG. 1 is a schematic view showing an overall configuration of a liquid fuel synthesis system including a middle distillate hydrotreating reactor according to an embodiment of the present invention. FIG. 2 is a detailed explanatory view around the middle distillate hydrotreating reactor according to the embodiment of the present invention. FIG. 3 is a schematic configuration diagram of the cloud point measuring unit shown in FIG. FIG. 4 is a flowchart showing an operation method of the middle distillate hydrotreating reactor according to the embodiment of the present invention. FIG. 5 is a graph showing the result of the confirmation experiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention (hereinafter, also referred to as “this embodiment”) will be described with reference to the accompanying drawings.
First, with reference to FIG. 1, the whole structure and process of the liquid fuel synthesis system (hydrocarbon synthesis reaction system) in which the operation method of the middle distillate hydrotreating reactor which is this embodiment is used are demonstrated.

As shown in FIG. 1, a liquid fuel synthesis system (hydrocarbon synthesis reaction system) 1 according to the present embodiment is a plant facility that executes a GTL process for converting a hydrocarbon raw material such as natural gas into liquid fuel. The liquid fuel synthesis system 1 includes a synthesis gas generation unit 3, an FT synthesis unit 5, and an upgrading unit 7.
The synthesis gas generation unit 3 reforms natural gas that is a hydrocarbon raw material to produce synthesis gas containing carbon monoxide gas and hydrogen gas.
The FT synthesis unit 5 produces liquid hydrocarbons from the synthesis gas produced in the synthesis gas generation unit 3 by an FT synthesis reaction.
The upgrading unit 7 produces liquid fuel (naphtha, kerosene, light oil, wax, etc.) by hydrotreating and fractionating the liquid hydrocarbon produced in the FT synthesis reaction. Hereinafter, components of each unit will be described.

The synthesis gas generation unit 3 mainly includes a desulfurization reactor 10, a reformer 12, an exhaust heat boiler 14, gas-liquid separators 16 and 18, a decarboxylation device 20, and a hydrogen separation device 26.
The desulfurization reactor 10 is composed of a hydrodesulfurization device or the like, and removes sulfur components from natural gas as a raw material.
The reformer 12 reforms the natural gas supplied from the desulfurization reactor 10 to generate a synthesis gas containing carbon monoxide gas (CO) and hydrogen gas (H ₂ ) as main components.
The exhaust heat boiler 14 recovers the exhaust heat of the synthesis gas generated in the reformer 12 and generates high-pressure steam.
The gas-liquid separator 16 separates water heated by heat exchange with the synthesis gas in the exhaust heat boiler 14 into a gas (high-pressure steam) and a liquid.
The gas-liquid separator 18 removes the condensate from the synthesis gas cooled by the exhaust heat boiler 14 and supplies the gas to the decarboxylation device 20.
The decarbonation device 20 has an absorption tower 22 that removes carbon dioxide gas from the synthesis gas supplied from the gas-liquid separator 18 by using the absorbent, and carbon dioxide is diffused from the absorbent containing the carbon dioxide to absorb the absorbent. And a regeneration tower 24 for regeneration.
The hydrogen separation device 26 separates a part of the hydrogen gas contained in the synthesis gas from the synthesis gas from which the carbon dioxide gas has been separated by the decarbonation device 20.
However, the decarboxylation device 20 may not be provided depending on circumstances.

The FT synthesis unit 5 includes, for example, a bubble column reactor (bubble column hydrocarbon synthesis reactor) 30, a gas / liquid separator 34, a separator 36, a gas / liquid separator 38, and a first rectifying column. 40 is mainly provided.
The bubble column reactor 30 is an example of a reactor that synthesizes liquid hydrocarbons from synthesis gas, and functions as a reactor for FT synthesis that synthesizes liquid hydrocarbons from synthesis gas by an FT synthesis reaction. The bubble column reactor 30 includes, for example, a bubble column type slurry bed in which a slurry in which solid catalyst particles are suspended in liquid hydrocarbon (product of FT synthesis reaction) is accommodated inside a column type container. Consists of a type reactor. The bubble column reactor 30 synthesizes liquid hydrocarbons by reacting carbon monoxide gas and hydrogen gas in the synthesis gas produced in the synthesis gas generation unit.
The gas-liquid separator 34 separates water heated through circulation in the heat transfer tube 32 disposed in the bubble column reactor 30 into water vapor (medium pressure steam) and liquid.
The separator 36 separates catalyst particles and liquid hydrocarbons in the slurry accommodated in the bubble column reactor 30.
The gas-liquid separator 38 is connected to the top of the bubble column reactor 30, the unreacted synthesis gas discharged from the bubble column reactor 30, and the product that is gaseous under the conditions of the bubble column reactor 30. The liquid product to be condensed is separated from the gas component.
The first rectifying column 40 fractionates the FT synthesis reaction product mainly composed of liquid hydrocarbons supplied from the bubble column reactor 30 through the separator 36 and the gas-liquid separator 38 into each fraction. To do.

The upgrading unit 7 includes, for example, a wax fraction hydrocracking reactor 50, a middle fraction hydrotreating reactor 52 according to this embodiment, a naphtha fraction hydrotreating reactor 54, and a gas-liquid separator. 56, 58, 60, a second rectifying tower 70, and a naphtha stabilizer 72.
The wax fraction hydrocracking reactor 50 is connected to the bottom of the first fractionator 40, and a gas-liquid separator 56 is provided downstream thereof.
The middle distillate hydrotreating reactor 52 is connected to the central portion of the first rectifying column 40, and a gas-liquid separator 58 is provided downstream thereof.
The naphtha fraction hydrotreating reactor 54 is connected to the top of the first rectifying column 40, and a gas-liquid separator 60 is provided downstream thereof.
The second rectification column 70 fractionates the liquid hydrocarbons supplied from the gas-liquid separators 56 and 58.
The naphtha stabilizer 72 rectifies the liquid hydrocarbons of the naphtha fraction supplied from the gas-liquid separator 60 and the second rectifying column 70, and discharges butane and lighter components than butane as flare gas, and has a carbon number. Five or more hydrocarbon components are separated and recovered as product naphtha.

  Next, a process (GTL process) of synthesizing liquid fuel from natural gas by the liquid fuel synthesizing system 1 having the above configuration will be described.

The liquid fuel synthesis system 1 is supplied with natural gas (main component is CH ₄ ) as a hydrocarbon feedstock from an external natural gas supply source (not shown) such as a natural gas field or a natural gas plant. The synthesis gas generation unit 3 reforms the natural gas to produce a synthesis gas (a mixed gas containing carbon monoxide gas and hydrogen gas as main components).

First, the natural gas is supplied to the desulfurization reactor 10 together with the hydrogen gas separated by the hydrogen separator 26. In the desulfurization reactor 10, the sulfur content contained in the natural gas is converted into hydrogen sulfide by the action of the hydrodesulfurization catalyst in the presence of hydrogen gas, and is adsorbed and removed by, for example, ZnO.
The desulfurized natural gas is mixed with carbon dioxide (CO ₂ ) gas supplied from a carbon dioxide supply source (not shown) and water vapor generated in the exhaust heat boiler 14, and then the reformer 12. To be supplied. The reformer 12 reforms natural gas using carbon dioxide and steam by the steam / carbon dioxide reforming method to generate high-temperature synthesis gas mainly composed of carbon monoxide gas and hydrogen gas. To do.

The high-temperature synthesis gas (for example, 900 ° C. and 2.0 MPaG) generated in the reformer 12 in this way is supplied to the exhaust heat boiler 14 and cooled by heat exchange with water flowing through the exhaust heat boiler 14. (For example, 400 ° C.). The water heated by the heat exchange becomes high-pressure steam, and the exhaust heat is recovered.
The synthesis gas cooled in the exhaust heat boiler 14 is supplied to the absorption tower 22 of the decarbonation apparatus 20 or the bubble column reactor 30 after the condensed liquid component is separated and removed in the gas-liquid separator 18. The absorption tower 22 separates carbon dioxide from the synthesis gas by absorbing the carbon dioxide contained in the synthesis gas in the stored absorption liquid. The absorption liquid containing carbon dioxide gas in the absorption tower 22 is introduced into the regeneration tower 24, and the absorption liquid containing carbon dioxide gas is heated and stripped by, for example, steam, and the released carbon dioxide gas is removed from the regeneration tower 24. To the reformer 12 and reused in the reforming reaction.

In this way, the synthesis gas produced in the synthesis gas generation unit 3 is supplied to the bubble column reactor 30 of the FT synthesis unit 5. At this time, the composition ratio of the synthesis gas supplied to the bubble column reactor 30 is adjusted to a composition ratio (for example, H ₂ : CO = 2: 1 (molar ratio)) suitable for the FT synthesis reaction.

  The hydrogen separator 26 separates hydrogen gas contained in the synthesis gas by adsorption and desorption (hydrogen PSA) using a pressure difference. The separated hydrogen gas is a variety of hydrogen that undergoes a predetermined reaction using hydrogen gas in the liquid fuel synthesis system 1 from a gas holder (not shown) or the like through a compressor (not shown). Continuously supplied to the reaction equipment (for example, desulfurization reactor 10, wax fraction hydrocracking reactor 50, middle fraction hydrotreating reactor 52, naphtha fraction hydrotreating reactor 54, etc.) .

  Next, the FT synthesis unit 5 synthesizes liquid hydrocarbons from the synthesis gas produced in the synthesis gas generation unit 3 by an FT synthesis reaction.

  The synthesis gas produced in the synthesis gas generation unit 3 flows from the bottom of the bubble column reactor 30 and rises in the slurry accommodated in the bubble column reactor 30. At this time, in the bubble column reactor 30, the carbon monoxide and hydrogen gas contained in the synthesis gas react with each other by the above-described FT synthesis reaction to synthesize hydrocarbons. The liquid hydrocarbon synthesized in the bubble column reactor 30 is introduced into the separator 36 together with the catalyst particles as a slurry.

The separator 36 separates the slurry into a solid content such as catalyst particles and a liquid content containing liquid hydrocarbons. Part of the solid content such as the separated catalyst particles is returned to the bubble column reactor 30, and the liquid content is supplied to the first fractionator 40. Further, from the top of the bubble column reactor 30, an unreacted synthesis gas and a gaseous hydrocarbon produced by the FT synthesis reaction under the conditions in the bubble column reactor 30 are separated into a gas-liquid separator. 38. The gas-liquid separator 38 cools these gases, separates the condensed liquid hydrocarbons, and introduces them into the first fractionator 40. On the other hand, a gas mixture separated by the gas-liquid separator 38, that is, a mixed gas mainly composed of unreacted synthesis gas (CO and H ₂ ) and a hydrocarbon gas having a small number of carbon atoms (C ₄ or less) is used as a bubble column. The unreacted synthesis gas recycled to the mold reactor 30 and included in the mixed gas is again used for the FT synthesis reaction. In addition, for the purpose of preventing high-concentration of gaseous hydrocarbons of C ₄ or less mainly in the FT synthesis reaction system by recycling the mixed gas, a part of the mixed gas is a bubble column reactor. Without being recycled to 30, it is introduced into an external combustion facility (flare stack, not shown), burned, and then released into the atmosphere.

Next, the first rectifying column 40 is an FT synthesis reaction product mainly composed of liquid hydrocarbons supplied from the bubble column reactor 30 through the separator 36 and the gas-liquid separator 38 as described above. Naphtha fraction (boiling point is lower than about 150 ° C.), middle distillate corresponding to kerosene / light oil (boiling point is about 150 to 350 ° C.), and wax fraction (boiling point exceeds about 350 ° C.). ) And fractional distillation.
The wax fraction (mainly C ₂₁ or more) extracted from the bottom of the first rectifying column 40 is transferred to the wax fraction hydrocracking reactor 50 and extracted from the center of the first rectifying column 40. Middle fraction (mainly C _{11 to} C ₂₀ ) is transferred to the middle fraction hydrotreating reactor 52 and extracted from the upper part of the first fractionator 40 (mainly C _{5 to} C ₁₀ ). Is transferred to the naphtha fraction hydrotreating reactor 54.

The wax fraction hydrocracking reactor 50 uses the hydrogen fraction supplied from the hydrogen separator 26 as a wax fraction (approximately C ₂₁ or more) extracted from the bottom of the first fractionator 40. by hydrocracking Te is converted to C ₂₀ or less hydrocarbons. In this hydrocracking reaction, using a catalyst and heat, the C—C bond of a hydrocarbon having a large number of carbon atoms is cut and converted to a hydrocarbon having a small number of carbon atoms. The product containing liquid hydrocarbons hydrocracked in the wax fraction hydrocracking reactor 50 is separated into gas and liquid in the gas-liquid separator 56, and the liquid hydrocarbons are separated from the second fractionator. The gas component including the hydrogen gas transferred to 70 is transferred to the middle distillate hydrotreating reactor 52 and the naphtha distillate hydrotreating reactor 54, and the hydrogen gas is reused.

The middle distillate hydrotreating reactor 52 removes the middle distillate liquid hydrocarbons (generally C _{11 to} C ₂₀ ) extracted from the center of the first rectifying column 40 from the hydrogen separator 26 and the wax distillate. Hydrorefining and hydroisomerization are performed using the hydrogen gas supplied via the hydrocracking reactor 50. The hydrorefined liquid hydrocarbon-containing product is separated into a gas and a liquid by the gas-liquid separator 58, and the liquid hydrocarbon is transferred to the second rectifying column 70, where a gas component (including hydrogen gas) is contained. .) Is reused in the hydrogenation reaction.

The naphtha fraction hydrotreating reactor 54 removes liquid hydrocarbons (generally C ₁₀ or less) of the naphtha fraction extracted from the upper part of the first rectifying column 40 from the hydrogen separation device 26 with a wax fraction. Hydrogen purification is performed using the hydrogen gas supplied through the fraction hydrocracking reactor 50. The hydrorefined liquid hydrocarbon-containing product (hydrorefined naphtha) is separated into a gas and a liquid by the gas-liquid separator 60, and the liquid hydrocarbon is transferred to the naphtha stabilizer 72, and the gas component (hydrogen Gas is reused) in the hydrogenation reaction.

Next, the second fractionator 70 converts the liquid hydrocarbons supplied from the wax fraction hydrocracking reactor 50 and the middle fraction hydrotreating reactor 52 as described above into hydrocarbons of C ₁₀ or less ( In the kerosene fraction (boiling point about 150-250 ° C.), light oil fraction (boiling point about 250-350 ° C.) and wax fraction hydrocracking reactor 50. It fractionates into a so-called uncracked wax fraction (boiling point above about 350 ° C.) where hydrocracking has not progressed sufficiently. An undecomposed wax fraction is withdrawn from the bottom of the second fractionator 70 and is recycled upstream of the wax fraction hydrocracking reactor 50 and re-supplied to the wax fraction hydrocracking reactor 50. Is done. A kerosene fraction and a light oil fraction are extracted from the center of the second rectifying tower 70. On the other hand, hydrocarbons of C ₁₀ or less are extracted from the top of the second rectifying column 70 and supplied to the naphtha stabilizer 72.

Further, the naphtha stabilizer 72 rectifies C ₁₀ or less hydrocarbons supplied from the tops of the naphtha fraction hydrotreating reactor 54 and the second rectifying column 70 to obtain a high-purity naphtha ( C ₅ -C ₁₀₎ the obtained from the column bottom. On the other hand, from the top of the naphtha stabilizer 72, a gas mainly composed of hydrocarbons of C ₄ or less which is not a product is discharged. This gas is introduced into an external combustion facility (not shown), burned, and then released into the atmosphere.

The process of the liquid fuel synthesis system 1 (GTL process) has been described above. By such a GTL process, natural gas is converted into liquid fuel such as high-purity naphtha (C _{5 to} C ₁₀ ), kerosene (C _{11 to} C ₁₅ ), and light oil (C _{16 to} C ₂₀ ).

Next, the configuration and operation around the middle distillate hydrotreating reactor 52 will be described in detail with reference to FIG.
The middle distillate hydrotreating reactor 52 discharges the supply path 101 connected to the center of the first rectifying column 40 and the middle distillate hydrofinished in the middle distillate hydrotreating reactor 52. Discharge path 102, sampling section 103 that collects a sample of the middle distillate that has been hydrorefined from the discharge path 102, and cloud point measurement that measures the cloud point of the collected sample of the middle distillate that has been hydrorefined And a control unit 104 that controls the operating conditions (hydrogen partial pressure / reaction temperature / middle distillate throughput per unit time (for example, LHSV)) of the middle distillate hydrotreating reactor 52. Yes.

The middle distillate hydrorefining step to which the operation method of the middle distillate hydrotreating reactor of this embodiment is applied is a step of hydrotreating and hydroisomerizing the middle distillate obtained by the FT synthesis reaction. is there. In the FT synthesis reaction, in addition to saturated hydrocarbons as main products, oxygen-containing compounds such as olefins and alcohols containing carbon monoxide-derived oxygen atoms are by-produced, and FT synthetic oil is fractionated. These by-products are also contained in the middle distillate obtained. Hydrorefining in the middle distillate hydrorefining step includes hydrogenation of the olefins to convert them to saturated hydrocarbons (paraffin hydrocarbons), and hydrodeoxygenation of oxygen-containing compounds to obtain saturated hydrocarbons and water. Mainly includes the reaction to convert to As a catalyst effective for this hydrorefining, a catalyst having a metal component having hydrogenation ability as an active site is used.
On the other hand, the hydroisomerization in the middle distillate hydrotreating process is a reaction for converting normal paraffin contained in the middle distillate into isoparaffin. As a catalyst effective for this hydroisomerization, a catalyst comprising a metal component having hydrogenation-dehydrogenation ability and a solid acid component is used. The normal paraffin is first dehydrogenated by the action of the metal component to become an olefin, and this olefin is skeletal isomerized by the action of the solid acid component, and further hydrogenated by the action of the metal component to be converted to isoparaffin.
In the middle distillate hydrorefining step, both a catalyst effective for hydrorefining and a catalyst effective for hydroisomerization may be used. In general, a catalyst effective for hydroisomerization is hydrogen. Therefore, it is efficient and preferable to use a catalyst effective for hydroisomerization.

  Although the form of the middle distillate hydrotreating reactor according to the present invention is not limited, it is preferably a fixed bed continuous flow reactor. The reactor may be a single reactor or a plurality of reactors arranged in series or in parallel. Moreover, the catalyst bed provided in a reactor may be single, and may be divided into plurality.

The catalyst charged in the middle distillate hydrotreating reactor is a catalyst generally used for hydrorefining and / or hydroisomerization in petroleum refining or the like, that is, hydrogenation (-dehydrogenation to an inorganic carrier). A catalyst on which an active metal having an ability is supported can be used.
As the active metal constituting the catalyst, one or more metals selected from the group consisting of metals of Group 6, Group 8, Group 9 and Group 10 of the periodic table of elements are used. Specific examples of these metals include noble metals such as platinum, palladium, rhodium, ruthenium, iridium and osmium, or cobalt, nickel, molybdenum, tungsten, iron, etc., preferably platinum, palladium, nickel, Cobalt, molybdenum and tungsten are preferable, and platinum and palladium are more preferable. These metals are also preferably used in combination of a plurality of types, and preferable combinations in that case include platinum-palladium, cobalt-molybdenum, nickel-molybdenum, nickel-cobalt-molybdenum, nickel-tungsten and the like. Further, when a combination of cobalt-molybdenum, nickel-molybdenum, nickel-cobalt-molybdenum, nickel-tungsten, etc. is used as the active metal, the catalyst may be sulfided with a sulfur compound before being subjected to hydrorefining. Good. Here, the periodic table of elements means a periodic table of long-period elements based on the provisions of IUPAC (International Pure Applied Chemistry Association).

  Examples of the inorganic carrier constituting the catalyst include metal oxides such as alumina, silica, titania, zirconia, and boria. These metal oxides may be one kind or a mixture of two or more kinds or composite metal oxides such as silica / alumina, silica / zirconia, alumina / zirconia, alumina / boria and the like. The inorganic carrier is a composite having solid acidity such as silica / alumina, silica / zirconia, alumina / zirconia, alumina / boria, etc., from the viewpoint of efficiently proceeding hydroisomerization of normal paraffin simultaneously with hydrorefining. A metal oxide is preferred. The inorganic carrier may contain a small amount of zeolite. Furthermore, the inorganic carrier may contain a binder for the purpose of improving the moldability and mechanical strength of the carrier. Preferred binders include alumina, silica, magnesia and the like.

  The content of the active metal in the catalyst is preferably about 0.1 to 3% by mass as a metal atom based on the mass of the support when the active metal is the above-mentioned noble metal. When the active metal is a metal other than the above-mentioned noble metal, the metal oxide is preferably about 2 to 50% by mass based on the mass of the support. When the content of the active metal is less than the lower limit, hydrorefining and hydroisomerization tend not to proceed sufficiently. On the other hand, when the content of the active metal exceeds the upper limit value, the dispersion of the active metal tends to decrease, and the activity of the catalyst tends to decrease, and the catalyst cost increases.

  The reaction temperature in the middle distillate hydrotreating reactor 52 in the present embodiment is 180 to 400 ° C, preferably 280 to 350 ° C, more preferably 300 to 340 ° C. Here, the reaction temperature is the average temperature of the catalyst layer in the middle distillate hydrotreating reactor 52. If the reaction temperature is equal to or higher than the lower limit temperature, the middle distillate is sufficiently hydrorefined and hydroisomerized, and if it is equal to or lower than the upper limit temperature, it is possible to suppress the simultaneous decomposition reaction of the middle distillate, Moreover, the lifetime reduction of a catalyst is suppressed.

  The pressure (hydrogen partial pressure) in the middle distillate hydrotreating reactor 52 is preferably 0.5 to 12 MPa, and more preferably 1 to 5 MPa. If the pressure of the hydrorefining reactor is 0.5 MPa or more, the crude middle distillate is sufficiently hydrorefined, and if it is 12 MPa or less, the equipment cost for increasing the pressure resistance of the equipment can be suppressed.

Intermediate liquid hourly space velocity in the fraction hydrotreating reactor 52 (LHSV [liquid hourly space velocity ]) is more be preferably from 0.1 to 10 ^-1, is 0.3 to 3.5 ^-1 preferable. If LHSV is 0.1 h ⁻¹ or more, the reactor volume does not need to be excessive, and if it is 10 h ⁻¹ or less, the middle distillate is efficiently hydrorefined and hydroisomerized.

  The hydrogen gas / oil ratio in the middle distillate hydrotreating reactor 52 is preferably 50 to 1000 NL / L, and more preferably 70 to 800 NL / L. Here, “NL” means the hydrogen capacity (L) in the standard state (0 ° C., 101325 Pa). If the hydrogen gas / oil ratio is 50 NL / L or more, the middle distillate is sufficiently hydrorefined and hydroisomerized. If it is 1000 NL / L or less, no equipment for supplying a large amount of hydrogen gas is required. In addition, an increase in operating costs can be suppressed.

  The above reaction conditions in the middle distillate hydrotreating reactor 52 are determined based on the measured cloud point of the hydrofinished middle distillate flowing out from the reactor.

  The sample of the middle distillate hydrorefined in the sampling unit 103 may be manually collected in a container, and the collected sample may be transported to an independent cloud point measuring unit, and the cloud point may be measured manually. . In that case, the sampling part 103 can be comprised, for example by installing a manual valve in the piping branched from the discharge path 102 double.

  On the other hand, the sampling unit 103 and the cloud point measuring unit 110 may be configured to automatically collect the sample and measure the cloud point, regardless of the manual operation. In this case, as the sampling unit 103, for example, a small-diameter pipe that branches off from the discharge path 102 and returns to the discharge path 102, and a plurality of pipes that are installed in the middle of the pipe and that are switched according to time are controlled. And a control mechanism for controlling opening and closing of the valve according to time. In the sampling unit 103, a small amount of a newly-produced hydrolysed middle distillate always circulates, and the sample is periodically collected by switching the valve. . The sampling unit 103 and the cloud point measuring unit 110 are connected by a pipe, and the sample collected by the sampling unit 103 is automatically transferred to the cloud point measuring unit 110. The cloud point measuring unit 110 automatically measures the cloud point of the transferred sample by interlocking the control of the valve of the sampling unit 103 with the control of the cloud point measuring unit 110. When the cloud point measurement is completed, the result is displayed on a display device provided on the control panel of the control unit 104 that controls the operation of the middle distillate hydrotreating reactor 52, for example. In the cloud point measuring unit 110, the hydrofinished middle distillate sample that has been measured is automatically discharged, and preparation for the next measurement is performed.

As shown in FIG. 3, the cloud point measuring unit 110 includes an aluminum container body 111 having a bottomed cylindrical shape, a lid part 112 that closes the opening of the container body 111, and a cooling unit that cools the container body 111. 113, a container temperature sensor 114 for measuring the temperature of the container body 111, a liquid temperature sensor 115 for measuring the temperature of the sample filled in the container body 111, and cloudiness of the sample filled in the container body 111 And a clouding detection unit 116 for detecting the above.
The cooling unit 113 is an electronic cooling unit using a Peltier element (not shown), and has a configuration capable of controlling the cooling rate. Moreover, the cloudiness detection part 116 is comprised with the optical sensor provided with the light projector and the light receiver.

A cloud point measuring method in the cloud point measuring unit 110 will be described.
First, a sample of the middle fraction obtained by hydrorefining is introduced into the container body 111. While the temperature is measured by the container temperature sensor 114 and the liquid temperature sensor 115, the middle distillate hydrorefined by the cooling unit 113 at a predetermined cooling rate is cooled, and the clouding detection unit 116 detects the occurrence of fogging. Let the liquid temperature at that time be the cloud point.
Here, the sample of the hydrotreated middle fraction collected is cooled by the cooling unit 113 under a cooling rate of 5.0 ° C./min to 15.0 ° C./min and the cloud point is measured. Is preferred. In the present embodiment, the cooling rate is 9.5 ° C./min.

Next, the operation method of the middle distillate hydrotreating reactor 52 will be described with reference to the flowchart of FIG.
The crude middle distillate distilled from the central portion of the first rectifying column 40 is supplied to the middle distillate hydrotreating reactor 52 through the supply path 101, and hydrorefined and hydroisomerized (S1). .
At the start-up of the middle distillate hydrotreating reactor 52, the initial operating conditions of the reactor are set. Further, during normal operation, when the cloud point measurement value of the hydrorefined middle distillate in the subsequent step is outside the target range, the operating condition of the reactor is changed (S2).

The hydrolysed middle distillate flowing out from the middle distillate hydrotreating reactor 52 through the discharge path 102 is sampled (S3).
The cloud point of the sampled hydrofinished middle distillate is measured by the cloud point measuring unit 110 described above (S4).
Then, the measured value of the cloud point is compared with the operation management target value, and it is determined whether or not the measurement value is within the operation management target range (S5).
If the cloud point is within the operation management target range, the operation condition of the middle distillate hydrotreating reactor 52 is maintained without being changed (S6). Even when the cloud point is within the operation management target range, the operation condition may be slightly changed for the purpose of bringing the cloud point closer to the operation management target center value, for example.
Then, the middle fraction that has been hydrorefined again after a predetermined time is sampled (return to S3), and the subsequent steps are repeated, whereby the stable state can be confirmed and maintained.
On the other hand, if the cloud point is outside the operation management target range, the control unit 104 determines the operation conditions of the middle distillate hydrotreating reactor 52 (hydrogen partial pressure / reaction temperature / middle distillate throughput per unit time (for example, , LHSV)) (return to S2).
Then, the middle fraction that has been hydrorefined again after a predetermined time is sampled (S3), and the subsequent steps are repeated. Thereby, it becomes possible to confirm the effect of changing the operating conditions of the middle distillate hydrotreating reactor 52 in S2.

Regarding the change of the operation conditions of the middle distillate hydrotreating reactor 52 in S2, specifically, when the cloud point exceeds the upper limit of the operation management target range, the hydrogen partial pressure is increased and / or the reaction temperature. And / or reducing the middle distillate throughput per unit time (LHSV) to promote hydroisomerization and lower the cloud point of the hydrofinished middle distillate. In addition, when the cloud point is below the lower limit of the operation management target range, the hydrogen partial pressure is reduced and / or the reaction temperature is lowered and / or the middle distillate throughput (LHSV) is increased. By adjusting the conditions, hydroisomerization is suppressed, and the cloud point of the hydrorefined middle distillate is raised. In particular, by changing the reaction temperature, the cloud point of the middle distillate effectively hydrorefined can be changed.
The control unit for controlling the operating conditions such as the hydrogen partial pressure of the middle distillate hydrotreating reactor 52, the reaction temperature, the middle distillate throughput per unit time, and the like controls general reactor operation control. It may be.

When the cloud point of the hydrorefined middle distillate flowing out from the middle distillate hydrotreating reactor 52 is outside the operation control target range, the reactor is adjusted so that the cloud point is within the operation control target range. Change the operating conditions, but treat the hydrorefined middle distillate that flows out until it is confirmed that the cloud point of the hydrofinished middle distillate that is flowing out is within the operation control target range Is not particularly limited.
When the cloud point of the hydrorefined middle distillate flowing out from the middle distillate hydrotreating reactor 52 is below the lower limit of the operation control target range, the middle distillate can be obtained by the increase of the light component due to the simultaneous decomposition reaction. The middle distillate product obtained through the fractionation in the second rectification column 70 may satisfy the product specification even if there is a problem in efficiency such as a reduction in the rate. The portion may be transferred to the second rectification column 70 and taken out as a product.
On the other hand, when the cloud point of the hydrorefined middle distillate flowing out from the middle distillate hydrotreating reactor 52 exceeds the upper limit of the operation control target range, the hydrofinished middle distillate is It may be transferred to the slop tank without being transferred to the two rectification tower 70. Alternatively, after temporarily storing in another storage facility, this was separately returned to the middle distillate hydrotreating reactor 52 and reprocessed to confirm that the cloud point was within the operation management target range. It may be transferred to the second rectifying column 70 and taken out as a product.
The second fractionator 70 includes not only the middle fraction hydrotreated from the middle fraction hydrotreating reactor 52 but also the hydrocracked product from the wax fraction hydrocracking reactor 50. Is also supplied. Therefore, even if the cloud point of the hydrorefined middle distillate flowing out from the middle distillate hydrotreating reactor 52 exceeds the upper limit of the operation management target range, it is obtained from the second rectification column 70. In some cases, the cloud point of a middle distillate product that meets the product specifications. Therefore, when it is estimated that the hydrolysed middle distillate is transferred to the second rectification column 70 and fractionated, and it is estimated that the obtained middle distillate satisfies the product specifications, this is taken out as a product. Also good. When the cloud point of the product exceeds the upper limit of the product specification, the product may be returned to the middle distillate hydrotreating reactor 52 and reprocessed.

  According to the middle distillate hydrotreating reactor 52 and the operation method of the middle distillate hydrotreating reactor 52 of the present embodiment configured as described above, from the middle distillate hydrotreating reactor 52, The cloud point of the produced hydrorefined middle distillate is measured, and the operation conditions of the middle distillate hydrotreating reactor 52 are controlled based on this cloud point. The degree of hydroisomerization in the hydrotreating reactor 52 is kept constant. Therefore, the properties of the hydrorefined middle distillate produced will be stabilized, and the quality of light oil (diesel fuel oil) produced using this hydrofinished middle distillate as a raw material will be greatly improved. be able to.

  Further, when measuring the cloud point, the cloud point was measured by cooling the middle distillate hydrorefined by the cooling unit 113 composed of an electronic cooling unit using a Peltier element, so that it was hydrorefined. It becomes possible to control the cooling rate of the middle distillate accurately and easily. In this embodiment, the cooling rate is 5.0 ° C./min or more and 15.0 ° C./min or less, more specifically, 9.5 ° C./min. And it becomes possible to carry out quickly. Thereby, control of the operating conditions by the control unit 104 can be performed at an appropriate timing, and the operation of the middle distillate hydrotreating reactor 52 can be stabilized.

As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included. For example, the cloud point measurement unit has been described as including a cooling unit composed of an electronic cooling unit using a Peltier device, but the present invention is not limited to this. For example, as shown in JIS K 2269, hydrorefining The resulting middle distillate may be cooled stepwise using a cooling bath to determine the cloud point.
Moreover, about the operating conditions, such as an upgrade unit, it is not limited to the range described in embodiment, You may change suitably according to a condition.
Further, the configurations of the synthesis gas generation unit 3, the FT synthesis unit 5, and the upgrading unit 7 are not limited to those described in the present embodiment, and the middle distillate of the FT synthetic hydrocarbon is the middle distillate. Any structure may be used as long as it is supplied to the hydrotreating reactor 52.

  Below, the result of the confirmation experiment performed in order to confirm the effect of this invention is demonstrated.

(Relationship between cloud point and degree of hydroisomerization)
Experiments were conducted to confirm the relationship between the degree of hydroisomerization in the middle distillate hydrotreating reactor and the cloud point (CP) of the hydrofinished middle distillate produced. The operating conditions of the middle distillate hydrotreating reactor were changed to produce a plurality of hydrofinished middle distillates having different cloud points, and samples of each hydrofinished middle distillate were collected. The cloud point of each hydrorefined middle distillate was measured at a cooling rate of 9.5 ° C./min by the cloud point measuring unit in the above-described embodiment. The degree of hydroisomerization in the middle distillate hydrotreating reactor when each hydrofinished middle distillate sample was obtained was about 19 or more carbon atoms in each sample determined by composition analysis. The normal paraffin content (n-C ₁₉₊ amount) was used as an index. The result of plotting n-C ₁₉₊ amount and CP is shown in FIG.

As shown in FIG. 5, there is a strong correlation between the cloud point of the hydrorefined middle distillate and the amount of n-C ₁₉₊ . Here, the amount of n-C ₁₉₊ serves as an index representing the degree of hydroisomerization. From this, it was confirmed that the degree of hydroisomerization in the middle distillate hydrotreating reactor can be determined by measuring the cloud point of the hydrofinished middle distillate.

(Measuring method of cloud point)
Next, when the method based on JIS K 2269 is used, and when the method of cooling the sample at a high cooling rate by the electronic cooling unit using the Peltier element shown in the present embodiment is hydrorefined. The measurement accuracy of the cloud point of the middle distillate and the time required for the measurement were confirmed.
Three types of liquid hydrocarbon samples (samples 1 to 3) having a boiling point range equivalent to diesel oil were prepared, and these samples were manufactured by Sosei Co., Ltd. Automatic pour point / cloud point / clogging point tester RPCF-03CML (product) No.) was measured by a measuring method based on JIS K 2269, and Examples 1 to 3 were obtained.
The above sample was cooled at a cooling rate of 5.0 ° C. by the cloud point measuring unit (specifically, an automatic pour point / cloud point tester model MPC-102 manufactured by Tanaka Scientific Instruments Manufacturing Co., Ltd.). / Min, 7.0 ° C./min, and 9.5 ° C./min. In Examples 1 to 12, the same cloud point measurement was repeated four times. The results are shown in Table 1.

  As shown in Table 1, the cloud point measured according to JIS K 2269, and the cloud point measured at each of the cooling rates of 5.0 ° C./min, 7.0 ° C./min, and 9.5 ° C./min Then, in the same sample, it agree | coincides with the error within 2 degreeC. Here, the error in JIS K 2269 is set to be within 2 ° C. in the same test apparatus and within 4 ° C. in different test apparatuses. Then, the error within 2 ° C. between Examples 1 to 3 and Examples 4 to 12 is within the allowable range in JIS K 2269, and the cooling rate is 5.0 ° C./min, 7.0 ° C. It was confirmed that even in Examples 4 to 12 measured under the respective conditions of / min and 9.5 ° C./min, the cloud point could be measured with the same accuracy as JIS K 2269.

In addition, in Examples 1 to 3 based on JIS K 2269, the measurement time was 60 to 90 minutes, whereas the cooling rates were 5.0 ° C./min, 7.0 ° C./min, 9.5. In Examples 4 to 12 measured under the respective conditions of ° C./min, measurement was possible in a short time of 6 to 21 minutes.
Therefore, it was confirmed that by measuring the cloud point as in Examples 4 to 12, the middle distillate hydrotreating reactor can be controlled reliably and more quickly.

  According to the method for operating a middle distillate hydrotreating reactor and the middle distillate hydrotreating reactor of the present invention, the hydrogenation in the hydrotreating step of the middle distillate of the FT synthesized hydrocarbon obtained by the FT synthesis reaction. The isomerization can be appropriately advanced to produce a hydrorefined middle distillate having a stable property, and a high quality light oil can be obtained.

DESCRIPTION OF SYMBOLS 1 Liquid fuel synthesis system 7 Upgrading unit 40 1st fractionator 52 Middle distillate hydrorefining reactor 103 Sampling part 104 Control part 110 Cloud point measuring part 113 Cooling part 116 Cloudiness detection part

Claims (8)

Method of operating a middle distillate hydrotreating reactor that hydrotreats and hydroisomerizes middle distillate containing components in the boiling range corresponding to diesel oil among FT synthesized hydrocarbons synthesized by Fischer-Tropsch synthesis reaction Because
Contacting the middle fraction with a catalyst to hydrotreat and hydroisomerize to obtain a hydrofinished middle fraction;
Measuring the cloud point of the hydrorefined middle distillate flowing out of the middle distillate hydrotreating reactor;
Controlling the operating conditions of the middle distillate hydrotreating reactor so that the cloud point becomes a predetermined target value;
Method of operating a middle distillate hydrotreating reactor equipped with   In the step of measuring the cloud point, the collected sample of the hydrofinished middle distillate is cooled at a cooling rate of 5.0 ° C./min or more and 15.0 ° C./min or less to obtain a cloud point. The method for operating a middle distillate hydrotreating reactor according to claim 1, wherein   3. The cloud point is measured in the step of measuring the cloud point by cooling the collected sample while controlling a cooling rate by an electronic cooling unit using a Peltier device. Of middle distillate hydrotreating reactor.   The process for controlling operating conditions of the middle distillate hydrotreating reactor controls at least one of hydrogen partial pressure, reaction temperature, and middle distillate throughput per unit time. The operation method of the middle distillate hydrorefining reactor as described in any one of these. A middle distillate hydrotreating reactor for hydrotreating and hydroisomerizing middle distillate containing components in the boiling range corresponding to light oil among FT synthesized hydrocarbons synthesized by Fischer-Tropsch synthesis reaction, ,
A sampling unit for collecting samples of the hydrofinished middle distillate to be produced;
A cloud point measuring unit for measuring the cloud point of the collected sample;
A middle distillate hydrotreating reactor. The sampling unit is connected to the cloud point measuring unit by piping, and the sample is automatically collected and transferred to the cloud point measuring unit,
6. The middle distillate hydrotreating reactor according to claim 5, wherein the cloud point measuring unit automatically measures the cloud point of the transferred sample.   The said cloud point measurement part is equipped with the cooling part which can cool the extract | collected said sample with the cooling rate of 5.0 degrees C / min or more and 15.0 degrees C / min or less. Middle distillate hydrotreating reactor.   The middle distillate hydrotreating reactor according to claim 7, wherein the cooling unit is an electronic cooling unit using a Peltier element.

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