CN107794083B - Hydrocarbon raw material fixed bed hydrogenation system and method thereof - Google Patents

Abstract

A fixed bed hydrogenation system for hydrocarbon raw materials and a method thereof, comprising a pretreatment reaction zone, a first gas-liquid separation zone, a main reaction zone and a second gas-liquid separation zone, wherein at least one fixed bed is arranged in the pretreatment reaction zone The reactor is filled with at least one hydrogenation protection agent and at least one first hydrogenation demetallization agent in sequence along the flow direction in the fixed bed reactor, and at least one fixed bed reactor is arranged in the main reaction zone, and the fixed bed The reactor is filled with at least one second hydrodemetallizing agent and at least one hydrodesulfurizing agent in sequence along the flow direction. The system provided by the invention has a high iron-holding capacity of the pretreatment reaction zone, and a relatively high capacity of the pretreatment reaction zone to intercept iron. It overcomes the problem of insufficient interception capability for iron-containing compounds in the prior art when the pretreatment reaction zone operates for a long period of time.

Description

A kind of hydrocarbon feedstock fixed bed hydrogenation system and method thereof

technical field

The present invention relates to a hydrocarbon feedstock hydrogenation system and a hydrogenation method thereof, more particularly a fixed bed hydrogenation system for hydrocarbon feedstocks and a hydrogenation method thereof.

Background technique

Reactor pressure drop is one of the main factors restricting the operating cycle of hydrocarbon hydrotreating or hydrotreating units. Taking the fixed-bed residue hydrogenation process as an example, the current operation cycle of the fixed-bed residue hydrogenation unit is generally between one year and one and a half years, while the operation cycle of the fixed-bed residue hydrogenation unit with high raw iron content Generally shorter, the main limiting factor is the pressure drop of the first or second reverse. Different from metals such as nickel and vanadium, which are mainly deposited in the catalyst pores, iron is mainly deposited on the outer surface of the catalyst after generating ferrous sulfide under hydrogenation conditions, while the deposition amount in the catalyst pores is small, which will lead to the porosity of the catalyst bed. Rapid reduction, and rapid reduction of catalyst bed void ratio will lead to a rapid increase in reactor pressure drop and eventually lead to premature shutdown of the unit, resulting in unnecessary economic losses.

Common methods for delaying the rise of pressure drop in industry include: (1) increasing the loading of the protective agent, but this method reduces the loading of the main catalyst. (2) Adopt the protection reactor that can be thrown off, when the pressure drop increases to the design limit, the protection reactor is short-circuited, and the stream directly enters the second reactor, but this method will cause the protection reactor to have half of the cycle unavailable. (3) The moving bed reactor is adopted, but the investment is greatly increased. (4) The switching protection reactor is adopted, the switching process is complicated and the investment is increased.

US6554994B1 adopts an up-flow reactor as a protective reactor, because the up-flow reactor has a slight expansion of the catalyst during normal operation, which can improve the metal-holding capacity of the catalyst. However, when processing raw materials with high iron content, although the pressure drop of the first reaction is not rising fast, iron will be deposited in the rear fixed-bed reactor during long-term operation, resulting in an increase in the pressure drop of the reactor.

CN1322097C discloses a method for hydrotreating heavy hydrocarbons with a switchable protection reactor. The method is provided with a switchable protection reactor system in front of the main reactor to remove heavy metal impurities and easy-to-produce impurities in the raw materials. The coke fouling product achieves the purpose of protecting the main catalyst. The protection reactor in this method needs to be switched to operate under high temperature and high pressure conditions, and the operation risk is relatively high.

CN1335368A discloses a hydrotreating method of heavy residual oil, which adopts a method of using one stage of adsorbent filter bed or one stage of adsorption filter agent bed and one stage of adsorption and filtration catalyst bed to remove suspended particles and rings in heavy residual oil. Ferrous sulfide formed from iron alkanoates. However, in this method, the adsorption filter bed can only remove suspended particles, and the adsorption and filtration catalyst bed needs to be operated under higher pressure, higher temperature and higher hydrogen-to-oil ratio, which is actually equivalent to the main process of residual oil hydrogenation. The method of increasing the loading of the protective agent in the reactor reduces the loading of the main catalyst.

CN201110326424 and CN201110326504 disclose a hydrotreating method of high acid and high calcium heavy crude oil. In the method, the high-acid and high-calcium heavy crude oil is mixed with hydrogen and then firstly enters a low-pressure hydroprocessing system for pretreatment, and the reactor of the pretreatment system is only filled with a hydrogenation protective agent. Studies have shown that iron-containing compounds will still enter the subsequent processing devices, and will still affect the subsequent processing devices, and will not fundamentally remove and effectively intercept iron-containing compounds.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the shortcoming that the pressure drop of the reactor rises faster when the existing hydrogenation method processes the hydrocarbon feedstock with higher iron content, and provides a hydrocarbon feedstock fixed bed hydrogenation system and a hydrogenation method thereof .

The fixed bed hydrogenation system for hydrocarbon raw materials provided by the present invention includes a pretreatment reaction zone, a first gas-liquid separation zone, a main reaction zone and a second gas-liquid separation zone, and the inlet of the pretreatment reaction zone is communicated with the raw material feed line , the outlet of the pretreatment reaction zone is communicated with the inlet of the first gas-liquid separation zone, the first gas-liquid separation zone has a gas-phase flow I outlet and a liquid-phase flow I outlet, and the liquid-phase flow I outlet is communicated with the inlet of the main reaction zone , the outlet of the main reaction zone is communicated with the inlet of the second gas-liquid separation zone, and the second gas-liquid separation zone has a gas-phase flow II outlet and a liquid-phase flow II outlet; the pretreatment reaction zone is provided with at least one fixed bed reactor, In the fixed-bed reactor, at least one hydrogenation protection agent and at least one first hydrodemetallization agent are sequentially loaded along the flow direction, wherein the particle size of the first hydrodemetallization agent loaded at the end of the flow direction is different. If the diameter is greater than 1.3 mm, at least one fixed bed reactor is arranged in the main reaction zone, and at least one second hydrodemetallizing agent and at least one hydrodesulfurizing agent are sequentially loaded in the fixed bed reactor along the flow direction.

The iron in the crude oil after electric desalination is mainly oil-soluble, and the oil-soluble iron includes iron petroleum acid, porphyrin iron and non-porphyrin iron. the difference. The inventors of the present invention have found that, in terms of reaction performance, most of the iron petroleum acid is relatively easy to react, and can also be removed by thermal cracking under non-hydrogen conditions, while the removal of porphyrin iron and non-porphyrin iron It is relatively difficult and requires a higher reaction temperature to achieve a higher removal rate. Under typical hydrotreating conditions, the removal of iron petroleum acid is relatively easy, but if the crude oil as a whole achieves a higher iron removal rate, it must be achieved at a higher reaction temperature.

In the existing fixed-bed residue hydrogenation process, the basic principle of catalyst gradation is that the pore size of the catalyst is from large to small along the flow direction, the content of active components is from low to high, and the particle size of the catalyst is from large to small. However, when the existing fixed bed residual oil hydrogenation catalyst grading technology is directly used in a device with a low hydrogen partial pressure pretreatment zone, since the pretreatment zone needs to operate at a higher reaction temperature and its hydrogen partial pressure is low, the pretreatment zone needs to be operated at a higher reaction temperature. The proportion of thermal cracking reaction in the treatment reactor increases, and the colloid and asphaltene macromolecules are prone to dehydrogenation and polycondensation, resulting in macromolecules with a higher degree of condensation. These highly condensed macromolecules will deposit on the catalyst in the main reactor in the form of coke, resulting in rapid deactivation of the catalyst. Therefore, existing fixed bed catalyst grading techniques cannot be applied to the pretreatment reaction zone of the present invention.

In addition, the industrial application results show that the fixed-bed residue hydrogenation unit with high raw iron content may have a rapid increase in the pressure drop of one or two reverses during the operation. The inventors of the present invention further researched and found that the deposition distribution of iron in different reactors is closely related to the catalyst particle size grading of the fixed bed device. In addition, the uniformity of iron deposition in the reactor has an important influence on the iron-holding capacity. The inventor of the present invention has conducted a multi-level and multi-directional analysis of iron deposition and believes that the reason why the protection reactor of the residual oil hydrogenation unit rises too fast is the inhomogeneity of iron deposition in the axial direction of the reactor and the radial direction of the catalyst particles caused. For example, under the same amount of iron deposition, the more uneven the distribution of iron catalyst particles in the radial direction, the faster the rise in reactor pressure drop.

In order to solve the above problems, the present invention provides a fixed bed hydrogenation system for hydrocarbon raw materials, which includes a pretreatment reaction zone, a first gas-liquid separation zone, a main reaction zone and a second gas-liquid separation zone. At least one fixed bed reactor is arranged in the pretreatment reaction zone, and at least one hydrogenation protection agent and at least one first hydrogenation demetallization agent are sequentially graded in the fixed bed reactor along the flow direction. One hydrodemetallization agent is a combination of 2-4 kinds of first hydrodemetallizers, and the particle size of each first hydrodemetallization agent gradually decreases along the flow direction. The particle size of the demetallizing agent is not more than 1.3 mm. Further preferably, the particle size of the hydrodemetallization agent loaded at the end of the stream direction is not greater than 1.1 mm. In one of the embodiments of the present invention, it is preferred that the hydrogenation protection agent is packed in combination of 2-4 hydrogenation protection agents, and the particle size of each hydrogenation protection agent gradually decreases along the flow direction.

The particle size mentioned in the present invention refers to the maximum value of the distance between any two points on the cross section of the catalyst.

The system provided by the invention not only has a high iron-holding capacity of the pretreatment reaction zone, but also has a relatively high capacity of intercepting iron in the pretreatment reaction zone. It overcomes the problem of insufficient interception capability for iron-containing compounds in the prior art when the pretreatment reaction zone operates for a long period of time.

In a preferred embodiment of the present invention, the active metal component content of the first hydrodemetallizing agent is greater than the active metal component content of the second hydrodemetallizing agent.

Further preferably, the active metal component content of the first hydrodemetallizing agent is 0.1-10% by weight more than the active metal component content of the second hydrodemetallizing agent.

In the present invention, one or more of the hydroprotection catalyst, the first hydrodemetallization agent, the second hydrodemetallization agent, and the hydrodesulfurization catalyst can be loaded respectively. Therefore, the first hydrodemetallization agent The active metal component content of the metal agent is greater than the active metal component content of the second hydrodemetallizing agent means that the average value of the active metal component content of the first hydrodemetallizing agent is greater than that of the second hydrodemetallizing agent The average value of the active metal component content of the metal agent.

In the present invention, based on the whole catalyst in the pretreatment reaction zone, the packing volume fraction of the hydrogenation protective agent is 20% to 95%, and the packing volume fraction of the first hydrogenation demetallization agent is 5% to 80%.

In one embodiment of the present invention, based on the overall catalyst in the pretreatment reaction zone, the packing volume fraction of the hydrogenation protective agent is 20% to 95%, and the packing volume fraction of the first hydrodemetallization agent is 5% to 80%. , wherein the filling volume fraction of the first hydrodemetallizing agent with a particle size not greater than 1.3 mm is 5% to 70%.

In one embodiment of the present invention, based on the overall catalyst in the pretreatment reaction zone, the packing volume fraction of the hydrogenation protective agent is 20% to 95%, and the packing volume fraction of the first hydrodemetallization agent is 5% to 80%. , wherein the filling volume fraction of the first hydrodemetallizing agent with a particle size not greater than 1.1 mm is 5% to 70%.

The gradation scheme of the hydrogenation protection agent and the hydrogenation demetallation agent can be optimized according to the pore structure and catalyst activity of the catalyst, as well as the properties of the raw materials and the hydrogenation operation conditions.

The hydrogenation protective agent contains a carrier and an active component supported on the carrier, the carrier is selected from one or more of alumina, silicon oxide and titanium oxide, and the active component is selected from Group VIB metals and/or Metals of Group VIII, based on the weight of the hydrogenation protective agent, calculated as oxides, the active component is 0-12% by weight, and the balance is the carrier.

The particle size of the hydrogenation protective agent is 3-50.0 mm, and the average pore diameter is 18-4000 nm.

The first hydrodemetallation agent contains a carrier and an active component supported on the carrier, the carrier is selected from one or more of aluminum oxide, silicon oxide and titanium oxide, and the active component is selected from metals in Group VIB and/or Group VIII metals, based on the weight of the first hydrodemetallizing agent, calculated as oxides, the active component is 3-30 wt%, and the balance is the carrier.

The particle size of the first hydrodemetallizing agent is 0.8-3 mm, and the average pore diameter is 10-30 nm.

The number of fixed-bed reactors set in the pretreatment reaction zone of the present invention is not particularly limited, and can be set as one fixed-bed reactor.

In another preferred embodiment of the present invention, 2-4 fixed-bed reactors in parallel are arranged in the pretreatment reaction zone, wherein multiple fixed-bed reactors may be online at the same time or only one fixed-bed reactor may be online at the same time.

The fixed bed reactor set in the pretreatment reaction zone can be either a down-flow reactor, an up-flow reactor, or a counter-flow reactor. The down-flow reactor refers to the reactor in which the material flows from top to bottom; the up-flow reactor refers to the reactor in which the material flows from the bottom to the top; the counter-flow reactor refers to the flow direction of liquid and gas. the opposite reactor.

In the present invention, at least one fixed bed reactor is arranged in the main reaction zone, and at least one second hydrodemetallization agent and at least one hydrodesulfurization agent are sequentially loaded in the fixed bed reactor along the flow direction.

Based on the whole catalyst in the main reaction zone, the packing volume fraction of the second hydrodemetallizing agent is 5% to 70%, and the packing volume fraction of the hydrodesulfurizing agent is 30% to 95%.

The second hydrodemetallation agent contains a carrier and an active component supported on the carrier, the carrier is selected from one or more of aluminum oxide, silicon oxide and titanium oxide, and the active component is selected from metals in Group VIB and/or Group VIII metals, based on the weight of the second hydrodemetallizing agent, calculated as oxides, the active component is 2.9-20% by weight, and the balance is the carrier. Preferably the active metal component is a nickel-tungsten, nickel-tungsten-cobalt, nickel-molybdenum or cobalt-molybdenum combination.

The particle size of the second hydrodemetallizing agent is 0.8-3 mm, and the average pore diameter is 9.9-29.9 nm.

The hydrodesulfurization agent contains a carrier and an active component supported on the carrier, the carrier is selected from one or more of alumina, silicon oxide and titanium oxide, and the active component is selected from Group VIB metals and/or The metal of Group VIII, based on the weight of the hydrodesulfurizing agent and calculated as the oxide, has an active component of 5 to 35% by weight, and the balance is a carrier. Preferably the active metal component is a nickel-tungsten, nickel-tungsten-cobalt, nickel-molybdenum or cobalt-molybdenum combination.

The particle size of the hydrodesulfurizing agent is 0.6-2 mm, and the average pore diameter is 7-15 nm.

More preferably, the bulk density of the catalyst described in the present invention is 0.3-1.2 g/cm ³ , and the specific surface area is 50-400 m ² /g.

According to the hydrogenation system of the present invention, in the main reaction zone along the flow direction, the pore size of the above-mentioned various hydrogenation catalysts gradually becomes smaller, the content of active metal components gradually increases, and the particle size gradually decreases.

In order to increase the impurity removal capability of the hydrogenation system of the present invention, thereby prolonging the operation period of the hydrogenation device, in a more preferred case, the average pore size of the first hydrogenation demetallation agent is larger than that of the second hydrogenation agent The average pore size of the demetallising agent.

In the system of the present invention, the main reaction zone can also be filled with any other conventional residual oil hydrogenation catalyst, such as one of a hydrogenation protection catalyst, a hydrogenation decarbonization catalyst and a hydrogenation denitrification catalyst or Various, the catalysts in the main reaction zone are graded according to conventional methods, that is, in the presence of the above-mentioned hydrogenation catalysts, the main reaction zone is sequentially filled with hydrogenation protection catalyst, second hydrogenation demetallization agent, hydrogenation protection catalyst along the flow direction Desulfurization catalyst, hydrodecarbon residue catalyst and hydrodenitrogenation catalyst.

The system provided by the invention can remove most of the iron-containing compounds in the hydrocarbon feedstock, and has not only a high iron-holding capacity of the pretreatment reaction zone, but also a relatively high capacity of the pretreatment reaction zone to intercept iron. It overcomes the problem of insufficient interception capability for iron-containing compounds in the prior art when the pretreatment reaction zone operates for a long period of time. It provides a good raw material for the subsequent main reaction zone, and can ensure the long-term operation of the main reaction zone, thereby increasing the operating efficiency of the overall system and improving the economy.

In a preferred embodiment of the present invention, the active metal component content of the first hydrodemetallizing agent in the pretreatment reaction zone is increased, so that the pretreatment reaction zone can achieve a higher deferrous rate at a relatively low temperature , reducing the proportion of thermal cracking reaction in the pretreatment reaction zone, thereby effectively reducing the amount of carbon deposits in the catalyst in the main reaction zone, and further extending the life of the catalyst in the main reaction zone.

According to the hydrogenation method of any one of the above systems, wherein the hydrocarbon feedstock is mixed with the first hydrogen-containing gas and then enters the pretreatment reaction zone, and is sequentially contacted with the hydrogenation protection agent and the first hydrogenation demetallization agent for reaction, and the reaction product is After entering the first gas-liquid separation zone, it is separated into a gas-phase stream I and a liquid-phase stream I, and the liquid-phase stream I enters the main reaction zone, and in the presence of the second hydrogen-containing gas, is sequentially mixed with the second hydrodemetallizing agent and hydrodesulfurization. The reagents are contacted to carry out the reaction, and the reaction product enters the second gas-liquid separation zone and is separated into a gas-phase stream II and a liquid-phase stream II, and the hydrogen partial pressure in the pretreatment reaction zone is 0.1 MPa to 4.0 MPa.

The iron content of the hydrocarbon feedstock is higher than 8 μg/g, preferably higher than 15 μg/g.

The hydrocarbon raw material is any iron-containing oil product, selected from one or more of diesel oil, wax oil, atmospheric residual oil, vacuum residual oil, deasphalted oil, coal tar and coal liquefaction heavy oil. Preferred are hydrocarbon feedstocks with an initial boiling point greater than 350°C.

In the present invention, in order to improve the diffusion performance of the hydrocarbon feedstock and increase the uniformity of iron deposition in the radial direction of the catalyst particles, in a preferred embodiment, water is mixed into the hydrocarbon feedstock and enters the pretreatment reaction zone together. The source of the water is not particularly limited, preferably deionized water. The ratio of the hydrocarbon feedstock to water is not particularly limited, preferably, the ratio of the hydrocarbon feedstock to water is 100:1-20, more preferably 100:2-15 by weight.

In another embodiment of the present invention, the water can also be provided by the water generated by the oxygen-rich hydrocarbon feedstock during the reaction process. The hydrocarbon feedstock is mixed with oxygen-rich hydrocarbon feedstock, and the ratio of the hydrocarbon feedstock to the oxygen-rich hydrocarbon feedstock is 100:1 to 30 by weight. The oxygen content of the raw material is 1% to 20%.

The oxygen-rich hydrocarbon raw material of the present invention is a biological oil, preferably a fatty acid chain triglyceride containing 14-18 carbon atoms.

The hydrogen content of the first hydrogen-containing gas is 20% to 100% by volume, preferably 40% to 80% by volume. The first hydrogen-containing gas can be selected from one or more kinds of refinery gas with hydrogen content between 20% and 100% by volume in the refinery, such as catalytic cracking dry gas, coking dry gas, and hydrogenation unit. Low-divided gas or reformed hydrogen, etc.

The hydrogen content of the second hydrogen-containing gas is 70% to 100% by volume, preferably hydrogen production hydrogen and/or reformed hydrogen.

Under the condition that the hydrogen partial pressure is 0.1MPa～4.0MPa, other conditions of the pretreatment reaction zone can be conventional conditions in the field, the reaction temperature of the pretreatment reaction zone is 100～400℃, the liquid hourly volume is empty The speed is 0.10～10.0h ^-1 , and the volume ratio of hydrogen to oil is 10～500. Preferably, the reaction temperature of the pretreatment reaction zone is 200-370° C., the liquid-hour volume space velocity is 0.6-6.0 h ⁻¹ , and the volume ratio of hydrogen to oil is 20-200.

The separation conditions of the first gas-liquid separation zone are well known to those skilled in the art, and the separation pressure in the first gas-liquid separation zone is the same as the pressure in the pretreatment reaction zone.

The reaction temperature of the main reaction zone is 300～460℃, preferably 350～420℃; the reaction pressure is 6～25MPa, preferably 12～20MPa; the liquid hourly volume space velocity is 0.1～1h ⁻¹ , preferably 0.2～20MPa 0.4h ^-1 ; the volume ratio of hydrogen to oil is 250-1500, preferably 300-1000.

The separation conditions of the second gas-liquid separation zone are well known to those skilled in the art, and are conventional hydrogen-liquid separation conditions.

The gas-phase stream II obtained from the second gas-liquid separation zone can be recycled after being processed. The liquid stream II obtained in the second gas-liquid separation zone can be sent to a downstream device, such as a catalytic cracking device, to obtain gasoline, diesel and other products after the catalytic cracking reaction.

Compared with the prior art, the method provided by the invention has the advantages of:

(1) The present invention is a method for removing iron-containing compounds from hydrocarbon feedstocks at a lower pressure and a lower hydrogen-to-oil ratio. In addition, the present invention can also use a low-quality hydrogen source with a lower hydrogen volume fraction, which is comparable to existing ones. Compared with the technology, only a small equipment investment and operating costs are required.

(2) The method of the present invention can effectively intercept the iron-containing compounds in the long-cycle operation by introducing the first hydrodemetallizing agent of small particles at the rear of the pretreatment reaction zone along the flow direction, and the long-term cycle of the main reaction zone The operation treatment provides better feed and improves the economy of the overall system operation.

(3) In the preferred method of the present invention, the introduction of water improves the diffusion performance of the hydrocarbon feedstock, increases the uniformity of iron deposition in the radial direction of the catalyst particles, and further delays the rise of the pressure drop in the pretreatment reaction zone.

Description of drawings

The accompanying drawing is a schematic diagram of the hydrocarbon feedstock fixed bed hydrogenation system provided by the present invention.

Detailed ways

The hydrocarbon feedstock fixed bed hydrogenation system and its hydrogenation method provided by the present invention will be further described below with reference to the accompanying drawings.

As shown in the figure, the present invention provides a fixed bed hydrogenation system for hydrocarbon feedstocks, wherein one embodiment includes a pretreatment reaction zone 1, a first gas-liquid separation zone 2, a main reaction zone 3 and a second gas-liquid separation zone 4, so The inlet of the pretreatment reaction zone 1 is communicated with the raw material feed line 5 and the first hydrogen-containing gas feed line 6, the outlet of the pretreatment reaction zone 1 is communicated with the inlet of the first gas-liquid separation zone 2 through the pipeline 7, and the first gas The gas-phase stream 1 outlet of the liquid separation zone 2 is connected with the gas-phase stream discharge line 8, the liquid-phase stream 1 outlet of the first gas-liquid separation zone 2 is communicated with the inlet of the main reaction zone 3 through the pipeline 9, and the second hydrogen-containing gas feed line 10 communicates with the inlet of the main reaction zone 3 . The outlet of the main reaction zone 3 is connected to the inlet of the second gas-liquid separation zone 4 through the pipeline 11, the gas-phase stream II outlet of the second gas-liquid separation zone 4 is connected to the discharge line 12, and the liquid-phase stream II of the second gas-liquid separation zone is connected. The outlet communicates with the discharge line 13 .

At least one fixed bed reactor is arranged in the pretreatment reaction zone, and at least one hydrogenation protection agent 1-1 and at least one first hydrogenation demetallization agent 1-2 are sequentially loaded in the fixed bed reactor along the flow direction. , wherein the particle size of the first hydrogenation demetallization agent loaded at the end of the flow direction is not greater than 1.3 mm, and at least one fixed-bed reactor is arranged in the main reaction zone, and the fixed-bed reactor is sequentially filled along the flow direction in the fixed-bed reactor. At least one second hydrodemetallizing agent 3-1 and at least one hydrodesulfurizing agent 3-2.

The specific features and use effects of the hydrocarbon feedstock fixed bed hydrogenation system and the hydrogenation method thereof of the present invention are further described below with reference to specific examples, but the present invention is not limited thereby.

The compositions and properties of the catalysts used in the examples and comparative examples are shown in Table 1, wherein G represents a hydrogenation protective agent, M represents a hydrodemetallization agent, S represents a hydrodesulfurization agent, and No. 1 and No. 2 represent different The catalysts such as M1 and M2 represent two different hydrodemetallation agents.

Table 1

The first hydrogen-containing gas used in each embodiment and comparative example is refinery gas, which is formed by mixing hydrogen, methane, ethane and propane in a certain proportion.

Examples 1-2

In Examples 1-2, a pretreatment reaction zone was set, and a single fixed bed reactor was set in the pretreatment reaction zone, and the hydrogenation protection agent and the first hydrogenation demetallization agent were sequentially filled in the reactor from bottom to top, and the catalyst loading ratio was such as As shown in Table 2, the particle size of the first hydrodemetallization agent loaded at the end of the flow direction is not greater than 1.3 mm. The hydrocarbon raw material is mixed with the hydrogen-containing gas and then enters the fixed-bed reactor, and is contacted with the hydrogenation protection agent and the first hydrogenation demetallization agent in turn to react, and the reaction product is extracted from the top of the fixed-bed reactor and enters the first gas-liquid separation. The post-zone is separated into a gas phase stream and a liquid phase stream. The hydrogen content of the hydrogen-containing gas in Example 1 was 50% by volume, and the hydrogen content of the hydrogen-containing gas in Example 2 was 100% by volume. The reaction conditions are shown in Table 3, and the properties of the raw materials and products are shown in Table 4.

As can be seen from the data in Table 4, the pretreatment reaction zone removed most of the iron in the hydrocarbon feedstock, effectively protecting the subsequent main reaction zone.

Example 3

Example 3 The fixed bed hydrogenation system provided by the present invention is adopted, including a pretreatment reaction zone, a first gas-liquid separation zone, a main reaction zone and a second gas-liquid separation zone, and a fixed bed reactor is arranged in the pretreatment reaction zone , set up a fixed bed reactor in the main reaction zone. The specific loading ratio of the catalyst is shown in Table 2. The particle size of the first hydrodemetallizing agent loaded at the end of the flow direction in the pretreatment reaction zone is not greater than 1.3 mm.

The hydrocarbon raw material is mixed with the first hydrogen-containing gas and then enters the first fixed-bed reactor (R-1), and is sequentially contacted with the hydrogenation protection agent and the first hydrogenation demetallization agent for reaction, and the reaction product enters the first gas-liquid The separation zone is followed by separation into a gas phase stream I and a liquid phase stream I. The liquid-phase stream I is mixed with the second hydrogen-containing gas and then enters the second fixed-bed reactor (R-2), and is contacted with the second hydrodemetallizing agent and the hydrodesulfurizing agent successively to react, and the reaction effluent is passed through the second gas. After the liquid separation zone, a gas phase stream II and a liquid phase stream II are obtained. The hydrogen content of the first hydrogen-containing gas was 70% by volume, and the hydrogen content of the second hydrogen-containing gas was 100% by volume. The reaction conditions are shown in Table 3.

The stability test of 8000h was carried out in Example 3, and the properties of raw materials and liquid phase flow II were shown in Table 5, and the iron content in liquid flow I was controlled to be no more than 3 μg/g, and the sulfur content in liquid flow II was no more than 0.2 by weight. %, when the system starts to run, the pressure drop of R-1 is 0.10MPa, and the pressure drop of R-2 is 0.20MPa. After the system runs for 8000h, the pressure drop of R-1 rises to 0.55MPa, the pressure drop of R-2 is 0.30MPa, and the pressure drop of R-2 is 0.30MPa. The reaction temperature of -2 was 410°C.

Comparative Example 1

The technical process of Comparative Example 1 is the same as that of Example 3, but the catalyst gradation scheme is different. The specific loading ratio is shown in Table 2, and the reaction conditions are shown in Table 3.

The stability test of 8000h was carried out in Comparative Example 1. The properties of the raw materials and the properties of the liquid phase II are shown in Table 5. The iron content in the liquid phase I was controlled not to exceed 3 μg/g, and the heating rate in the pretreatment zone was the same as that in Example 3. , while controlling the sulfur content in liquid stream II to not exceed 0.2 wt%, when the device starts to run, the pressure drop of R-1 is 0.06MPa, and the pressure drop of R-2 is 0.17MPa. After the device runs for 8000h, the pressure drop of R-1 rises At 0.43MPa, the pressure drop of R-2 rose to 0.65MPa, and the reaction temperature of R-2 was 420°C.

It can be seen from the comparison that after running for 8000h in Comparative Example 1, the pressure drop of R-2 is significantly higher than that of R-2 in Example 3, and the reaction temperature of R-2 is also higher than that of Example 3. It can be seen that the system provided by the present invention can effectively intercept iron-containing compounds in the pretreatment reaction zone, provide better raw materials for the long-cycle operation of the main reaction zone, and improve the economy of the entire system.

Example 4

The technical process of Example 4 is the same as that of Example 3, the catalyst grading and loading scheme is shown in Table 2, and the reaction conditions are shown in Table 3.

The stability test of 8000h was carried out in Example 4. The properties of the raw materials and the properties of liquid phase flow II are shown in Table 5. The iron content in the liquid phase flow I was controlled to be no more than 3 μg/g, and the sulfur content in the liquid flow II was controlled to be no more than 0.2 μg/g. % by weight, when the device starts to run, the pressure drop of R-1 is 0.10MPa, and the pressure drop of R-2 is 0.20MPa. After the device runs for 8000h, the pressure drop of R-1 rises to 0.55MPa, and the pressure drop of R-2 is 0.29MPa. The reaction temperature of R-2 was 405°C.

It can be seen from the comparison between Example 3 and Example 4 that the reaction temperature of R-2 in Example 4 is 5°C lower than the reaction temperature of R-2 in Example 3, indicating that by increasing the first hydrogenation in the pretreatment reaction zone The activity of the demetallizing agent can effectively reduce the deactivation rate of carbon deposition in the main reaction zone and prolong the operation period of the main reaction zone.

Example 5

The technical process of Example 5 is the same as that of Example 3, the catalyst grading and loading scheme is shown in Table 2, and the reaction conditions are shown in Table 3.

The stability test of 8000h was carried out in Example 5. The properties of the raw materials and the properties of liquid phase II are shown in Table 5. The iron content in the liquid phase I was controlled to be no more than 3 μg/g, and the sulfur content in the liquid phase II was controlled to be no more than 0.2 μg/g. % by weight, when the device starts to operate, the pressure drop of R-1 is 0.11MPa, and the pressure drop of R-2 is 0.20MPa. After the device runs for 8000h, the pressure drop of R-1 rises to 0.56MPa, and the pressure drop of R-2 is 0.25MPa. The reaction temperature of R2 was 404°C.

Comparative Example 2

The technical process of Comparative Example 2 is the same as that of Example 4, but the catalyst gradation scheme is different. The specific loading ratio is shown in Table 2, and the reaction conditions are shown in Table 3.

Comparative example 2 has carried out the stability test of 8000h, the properties of raw materials and liquid phase flow II are shown in Table 5, and the iron content in liquid flow I is controlled not to exceed 3 μg/g, and the heating rate in the pretreatment zone is the same as in Example 4. , while controlling the sulfur content in liquid stream II to not exceed 0.2 wt%, when the device starts to run, the pressure drop of R-1 is 0.06MPa, and the pressure drop of R-2 is 0.17MPa. After the device runs for 8000h, the pressure drop of R-1 rises When it reaches 0.47MPa, the pressure drop of R-2 rises to 0.62MPa, and the reaction temperature of R2 is 417℃.

It can be seen from the comparison that after running for 8000h in Comparative Example 2, the pressure drop of R-2 is significantly higher than that of R-2 in Example 4, and the reaction temperature of R-2 is also higher than that of Example 4. It can be seen that the system provided by the present invention can effectively intercept iron-containing compounds in the pretreatment reaction zone, provide better raw materials for the long-cycle operation of the main reaction zone, and improve the economy of the entire system operation.

Examples 6 to 7

In Examples 6-7, a pretreatment reaction zone was set, and a single fixed bed reactor was set in the pretreatment reaction zone, and the hydrogenation protection agent and the hydrogenation demetallization agent were sequentially filled in the reactor from bottom to top. The catalyst loading ratio is shown in Table 2. shown. The hydrocarbon raw material, water and hydrogen-containing gas are mixed into the fixed-bed reactor, and then contacted with the hydrogenation protection agent and the first hydrogenation demetallization agent for reaction, and the reaction product is extracted from the top of the fixed-bed reactor and enters the first gas The liquid separation zone is then separated into a gas phase stream and a liquid phase stream. The hydrogen content of the hydrogen-containing gas in Example 6 was 50% by volume, and the hydrogen content of the hydrogen-containing gas in Example 7 was 100% by volume. The reaction conditions are shown in Table 6, and the properties of the raw materials and products are shown in Table 7.

As can be seen from the data in Table 7, the pretreatment reaction zone removed most of the iron in the hydrocarbon feedstock, effectively protecting the subsequent main reaction zone.

Example 8

This example adopts the same fixed bed hydrogenation system and catalyst loading ratio as in Example 3. The hydrocarbon raw material, water and the first hydrogen-containing gas are mixed into the first fixed-bed reactor (R-1), and then contacted with the hydrogenation protection agent and the first hydrogenation demetallization agent to react in turn, and the reaction product enters the first fixed-bed reactor (R-1). The gas-liquid separation zone is separated into a gas-phase stream I and a liquid-phase stream I. The liquid-phase stream I is mixed with the second hydrogen-containing gas and then enters the second fixed-bed reactor (R-2), and is contacted with the second hydrodemetallizing agent and the hydrodesulfurizing agent successively to react, and the reaction effluent is passed through the second gas. After the liquid separation zone, a gas phase stream II and a liquid phase stream II are obtained. The hydrogen content of the first hydrogen-containing gas was 70% by volume, and the hydrogen content of the second hydrogen-containing gas was 100% by volume. The reaction conditions are shown in Table 6.

The stability test of 8000h was carried out in Example 8, and the properties of raw materials and liquid phase flow II were shown in Table 8, wherein the iron content in liquid flow I was controlled to be no more than 3 μg/g, and the sulfur content in liquid flow II was no more than 0.2 by weight. %, when the system starts to run, the pressure drop of R-1 is 0.10MPa, and the pressure drop of R-2 is 0.20MPa. After the system runs for 8000h, the pressure drop of R-1 rises to 0.52MPa, the pressure drop of R-2 is 0.30MPa, and the pressure drop of R-2 is 0.30MPa. The reaction temperature of -2 was 410°C.

In the preferred method provided by the present invention, by introducing water into the hydrocarbon feedstock, the radial distribution of iron in the catalyst particles can be improved, the rise of the pressure drop of the reactor in the low pressure zone can be delayed, and the iron-containing compounds can be further effectively intercepted.

Example 9

This example adopts the same fixed bed hydrogenation system and catalyst loading ratio as in Example 4. The reaction conditions are shown in Table 6.

The stability test of 8000h was carried out in Example 9. The properties of the raw materials and the properties of liquid phase flow II were shown in Table 8. The iron content in liquid flow flow I was controlled to be no more than 3 μg/g, and the sulfur content in liquid flow flow II was controlled to be no more than 0.2 μg/g. % by weight, when the device starts to operate, the pressure drop of R-1 is 0.10MPa, and the pressure drop of R-2 is 0.20MPa. After the device runs for 8000h, the pressure drop of R-1 rises to 0.53MPa, and the pressure drop of R-2 is 0.29MPa. The reaction temperature of R-2 was 405°C.

In the preferred method provided by the present invention, by introducing water into the hydrocarbon feedstock, the radial distribution of iron in the catalyst particles can be improved, the rise of the pressure drop of the reactor in the low pressure zone can be delayed, and the iron-containing compounds can be further effectively intercepted.

Table 2

table 3

Table 4

project Raw material A Example 1 Example 2 Liquid stream I Density (20℃), g/cm³ 0.9687 0.9474 0.9512 Sulfur, wt% 3.37 2.79 3.13 Metal content, μg/g nickel 45.1 40.0 44.6 vanadium 19.6 16.4 18.4 iron 21.8 4.9 6.7

table 5

Table 6

Table 7

project Raw material A Example 6 Example 7 Liquid stream I Density (20℃), g/cm³ 0.9687 0.9476 0.9515 Sulfur, wt% 3.37 2.77 3.10 Metal content, μg/g nickel 45.1 40.1 44.8 vanadium 19.6 16.1 18.5 iron 21.8 4.6 6.4

Table 8

project Raw material B Example 8 Example 9 Liquid Stream II Density (20℃), g/cm³ 0.9734 0.9281 0.9268 Sulfur, wt% 1.75 0.20 0.20 Metal content, μg/g nickel 38.5 7.9 7.1 vanadium 18.9 3.2 2.8 iron 16.4 1.0 0.9

Claims (28)

1. A fixed bed hydrogenation system for hydrocarbon raw materials comprises a pretreatment reaction zone, a first gas-liquid separation zone, a main reaction zone and a second gas-liquid separation zone, wherein an inlet of the pretreatment reaction zone is communicated with a raw material feeding line, an outlet of the pretreatment reaction zone is communicated with an inlet of the first gas-liquid separation zone, the first gas-liquid separation zone is provided with a gas-phase material flow I outlet and a liquid-phase material flow I outlet, the liquid-phase material flow I outlet is communicated with an inlet of the main reaction zone, an outlet of the main reaction zone is communicated with an inlet of the second gas-liquid separation zone, and the second gas-liquid separation zone is provided with a gas-phase material flow II outlet and a liquid; set up at least one fixed bed reactor in the preliminary treatment reaction zone, pack at least one hydrogenation protective agent and at least one first hydrogenation demetallization agent in proper order along the commodity circulation direction in fixed bed reactor, wherein, the particle diameter of the first hydrogenation demetallization agent that packs at commodity circulation direction end position is not more than 1.3mm, set up at least one fixed bed reactor in the main reaction zone, pack at least one second hydrogenation demetallization agent and at least one hydrodesulfurization agent in proper order along the commodity circulation direction in fixed bed reactor.

2. The system of claim 1, wherein the first hydrodemetallization agent is a combination of 2 to 4 first hydrodemetallization agents, the first hydrodemetallization agent has a gradually decreasing particle size along the flow direction, and the first hydrodemetallization agent is filled at the end of the flow direction to have a particle size of not more than 1.3 mm.

3. The system of claim 1 or 2, wherein the first hydrodemetallization agent is charged at the end portion in the direction of flow with a particle size of not more than 1.1 mm.

4. The system according to claim 1, wherein the hydrogenation protective agent comprises a carrier and an active component loaded on the carrier, the carrier is one or more selected from alumina, silica and titanium oxide, the active component is selected from group VIB metals and/or group VIII metals, the weight of the hydrogenation protective agent is taken as a reference, the active component accounts for 0-12 wt% of the oxide, and the balance is the carrier.

5. The system of claim 4, wherein the hydro-protectant has a particle size of 3 to 50.0mm and an average pore size of 18 to 4000 nm.

6. The system of claim 1 or 2, wherein the first hydrodemetallization agent has an active metal component content that is greater than an active metal component content of the second hydrodemetallization agent.

7. The system of claim 6, wherein the first hydrodemetallization agent has an active metal component content of 0.1 to 10 wt.% more than the active metal component content of the second hydrodemetallization agent.

8. The system according to claim 1 or 6, wherein the first hydrodemetallization agent comprises a carrier and an active component loaded on the carrier, the carrier is one or more selected from alumina, silica and titania, the active component is selected from a group VIB metal and/or a group VIII metal, the active component accounts for 3-30 wt% of the oxide based on the weight of the first hydrodemetallization agent, and the balance is the carrier.

9. The system of claim 8, wherein the first hydrodemetallization agent has a particle size of 0.8 to 3mm and an average pore size of 10 to 30 nm.

10. The system according to claim 1 or 6, wherein the second hydrodemetallization agent comprises a carrier and an active component loaded on the carrier, the carrier is one or more selected from alumina, silica and titania, the active component is selected from a group VIB metal and/or a group VIII metal, the active component accounts for 2.9-20 wt% of the oxide based on the weight of the second hydrodemetallization agent, and the balance is the carrier.

11. The system of claim 10, wherein the second hydrodemetallization agent has a particle size of 0.8 to 3mm and an average pore size of 9.9 to 29.9 nm.

12. The system according to claim 1 or 2, wherein the hydrodesulfurization agent comprises a carrier and an active component loaded on the carrier, the carrier is one or more selected from alumina, silica and titanium oxide, the active component is selected from group VIB metals and/or group VIII metals, the weight of the active component is 5-35 wt% calculated by oxides based on the weight of the hydrodesulfurization agent, and the balance is the carrier.

13. The system of claim 12, wherein the hydrodesulfurization agent has a particle size of 0.6 to 2mm and an average pore size of 7 to 15 nm.

14. The system of claim 1, wherein the loading volume fraction of the hydrogenation protective agent is 20-95% and the loading volume fraction of the first hydrodemetallization agent is 5-80% based on the pretreatment reaction zone monolithic catalyst.

15. The system of claim 1 or 2, wherein the loading volume fraction of the hydrogenation protective agent is 20-95% and the loading volume fraction of the first hydrodemetallization agent is 5-80%, based on the pretreatment reaction zone monolithic catalyst, and wherein the loading volume fraction of the first hydrodemetallization agent with a particle size of not more than 1.3mm is 5-70%.

16. The system of claim 3, wherein the loading volume fraction of the hydrogenation protective agent is 20-95% and the loading volume fraction of the first hydrodemetallization agent is 5-80%, based on the pretreatment reaction zone monolithic catalyst, and wherein the loading volume fraction of the first hydrodemetallization agent having a particle size of not greater than 1.1mm is 5-70%.

17. The system of claim 1, wherein the packed volume fraction of the second hydrodemetallization agent is 5-70% and the packed volume fraction of the hydrodesulfurization agent is 30-95% based on the total catalyst in the main reaction zone.

18. The system of claim 1, wherein 2-4 fixed bed reactors are arranged in parallel in the pretreatment reaction zone.

19. A method according to any one of claims 1 to 18, wherein the hydrocarbon feedstock is mixed with a first hydrogen-containing gas and then fed into a pretreatment reaction zone, and is sequentially contacted with a hydrogenation protecting agent and a first hydrodemetallization agent to react, the reaction product is fed into a first gas-liquid separation zone and then separated into a gas phase material flow I and a liquid phase material flow I, the liquid phase material flow I is fed into a main reaction zone and is sequentially contacted with a second hydrodemetallization agent and a hydrodesulfurization agent to react in the presence of a second hydrogen-containing gas, the reaction product is fed into a second gas-liquid separation zone and then separated into a gas phase material flow II and a liquid phase material flow II, and the hydrogen partial pressure in the pretreatment reaction zone is 0.1 MPa-4.0 MPa.

20. The process of claim 19, wherein the iron content of the hydrocarbon feedstock is greater than 8 μ g/g.

21. The method of claim 20, wherein the hydrocarbon feedstock is selected from one or more of diesel oil, wax oil, long residue, short residue, deasphalted oil, coal tar, and heavy coal-to-liquid oil.

22. The method of claim 19, wherein the hydrogen content of the first hydrogen-containing gas is 20% to 100% by volume.

23. The method of claim 22, wherein the hydrogen content of the first hydrogen containing gas is between 40% and 80% by volume.

24. The method of claim 19, wherein the reaction temperature of the pretreatment reaction zone is 100-400 ℃, and the liquid hourly space velocity is 0.10-10.0 h^-1The volume ratio of hydrogen to oil is 10-500.

25. The method of claim 19, wherein the reaction temperature of the main reaction zone is 300-460 ℃, the reaction pressure is 6-25 MPa, and the liquid hourly space velocity is 0.1-1 h^-1The volume ratio of hydrogen to oil is 250-1500.

26. The process of claim 19, wherein the hydrocarbon feedstock is admixed with water and passed together into the pretreatment reaction zone in a ratio of hydrocarbon feedstock to water of 100: 1 to 20.

27. The process of claim 26, wherein the ratio of hydrocarbon feedstock to water is 100: 2 to 15.

28. The process of claim 19, wherein the hydrocarbon feedstock is admixed with the oxygen-enriched hydrocarbon feedstock and passed together into the pretreatment reaction zone in a ratio of 100: 1-30 percent of oxygen-enriched hydrocarbon raw material, wherein the oxygen content of the oxygen-enriched hydrocarbon raw material is 1-20 percent based on the weight of the oxygen-enriched hydrocarbon raw material.

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