CN114806627A

CN114806627A - Two-phase deferrization method for hydrocarbon raw material

Info

Publication number: CN114806627A
Application number: CN202110123975.3A
Authority: CN
Inventors: 邓中活; 聂红; 邵志才; 戴立顺; 胡志海; 刘涛; 施瑢; 牛传峰; 聂鑫鹏; 任亮; 方强; 张奎; 胡大为; 孙淑玲
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2021-01-29
Filing date: 2021-01-29
Publication date: 2022-07-29

Abstract

A process for dual-phase deferrization of hydrocarbon raw material includes such steps as introducing the hydrocarbon raw material into deferrization reaction zone, sequentially contacting with hydrogenating protecting agent and hydrodemetalizing agent in the absence of hydrogen atmosphere for reaction to obtain the resultant with low S and Fe contents, and controlling the reaction depth to make the S content difference between raw hydrocarbon material and raw hydrocarbon material be not less than 10. The hydrocarbon two-phase deferrization method provided by the invention can be used for removing most of iron-containing compounds in the hydrocarbon raw materials at low cost and providing a feed with low impurity content for a subsequent device, thereby ensuring the long-term operation of the subsequent device and improving the economy.

Description

Two-phase deferrization method for hydrocarbon raw material

Technical Field

The invention relates to a two-phase deferrization method for hydrocarbon raw materials, in particular to a fixed bed two-phase deferrization method for hydrocarbon raw materials.

Background

The iron content of a hydrocarbonaceous feedstock is one of the major factors that limit the run length of a hydrotreating or hydrofinishing unit. Different from the condition that metals such as nickel, vanadium and the like are mainly deposited in catalyst pore channels, iron is mainly deposited on the outer surface of a catalyst after being subjected to ferrous sulfide generation under the hydrogenation condition, the deposition amount in the catalyst pores is small, the void ratio of a catalyst bed layer is rapidly reduced, the rapid reduction of the void ratio of the catalyst bed layer can cause the pressure drop of a reactor to rapidly rise and finally lead a device to be shut down in advance, and unnecessary economic loss is caused.

Common methods for industrial units to retard the pressure drop rise in reactors in response to the high iron content of the hydrocarbon feedstock include, but are not limited to: (1) the loading of the protectant is increased, but the process reduces the loading of the procatalyst. (2) A guard reactor is used which can be thrown off and when the pressure drop increases to the design limit the guard reactor is short circuited and the stream is directed to the second reactor, but this method will cause the guard reactor to be partially cycle unusable. (3) A moving bed reactor is adopted, but the investment is greatly increased. (4) The switching protection reactor is adopted, the switching process is complex and the investment is increased; (5) the low-pressure hydrogenation and de-ironing pretreatment technology is adopted, but the problems of complex technology and the like exist.

US6554994B1 uses an upflow reactor as a guard reactor, which improves the metal-tolerant capacity of the catalyst due to slight catalyst expansion during normal operation of the upflow reactor. However, in the case of processing a high iron content raw material, although the rate of increase in pressure drop is not rapid in the opposite direction, iron is deposited in the rear fixed bed reactor during a long period of operation, resulting in an increase in pressure drop in the reactor.

CN1322097C discloses a method for hydrotreating heavy hydrocarbons with a switchable guard reactor, which is to arrange a switchable guard reactor system in front of a main reactor to remove heavy metal impurities and coking scaling substances in raw materials, thereby achieving the purpose of protecting the main catalyst. The protective reactor in the method needs to be switched to operate under the conditions of high temperature and high pressure, and the operation risk is high.

CN1335368A discloses a heavy residual oil hydrotreating method, which uses a first-stage adsorbent filter bed or a first-stage adsorbent filter bed and a first-stage adsorption filter catalyst bed to remove suspended particles in heavy residual oil and ferrous sulfide generated by iron naphthenate. However, in the method, the bed layer of the adsorption filter can only remove suspended particles, and the bed layer of the adsorption filtration catalyst needs to be operated under higher pressure, higher temperature and higher hydrogen-oil ratio, which is actually equivalent to the method of increasing the loading of the protective agent in the main reactor for residual oil hydrogenation, so that the loading of the main catalyst is reduced.

CN103059932A discloses a hydrotreating method of high-acid high-calcium heavy crude oil. In the method, high-acid high-calcium heavy crude oil is mixed with hydrogen and then enters a low-pressure hydrotreating system for pretreatment, and only a hydrogenation protective agent is filled in a reactor of the pretreatment system. Research shows that the iron-containing compounds still enter the subsequent treatment device and still affect the subsequent treatment device, and the effects of fundamentally removing and effectively intercepting the iron-containing compounds are not achieved.

CN 107794086A discloses a hydrocarbon low-pressure hydrodeironing system and a method, which realize better iron removing effect by catalyst grading and optimization of process conditions, but the technology still needs a hydrogen system and a separation system, and the cost is higher.

Disclosure of Invention

The invention aims to overcome the defect of higher cost when the existing hydrogenation method is used for processing hydrocarbon raw materials with higher iron content, and provides a two-phase deferrization method for the hydrocarbon raw materials.

The inventor of the invention researches and discovers that the iron in the crude oil after electro-desalting is mainly oil-soluble, the oil-soluble iron comprises iron oleate, porphyrin iron and non-porphyrin iron, and the proportion of the three types of iron is different according to different raw material sources. Under typical hydrotreating conditions, most of the iron petroleate reacts more easily, while the removal of iron porphyrins and non-iron porphyrins is relatively difficult, and higher removal rates need to be achieved at higher reaction temperatures. The inventors of the present invention have further found that the key to increase the iron removal rate of the hydrocarbon feedstock is to provide a certain amount of hydrogen sulfide to promote the iron removal reaction according to the iron content of the hydrocarbon feedstock, and to control the flow velocity in the reactor to facilitate the deposition of ferrous sulfide.

Based on the research, the invention provides a two-phase deferrization method for hydrocarbon raw materials, the hydrocarbon raw materials enter a deferrization reaction zone and are sequentially contacted with a hydrogenation protective agent and a hydrogenation demetalization agent for reaction in the absence of hydrogen atmosphere to obtain reaction effluents with reduced sulfur content and iron content, and the reaction depth is controlled so that the difference value of the sulfur content in the hydrocarbon raw materials before and after the reaction/the iron content in the hydrocarbon raw materials is not less than 10.

In one embodiment of the invention, the depth of the reaction is controlled so that the difference in sulfur content in the hydrocarbon feedstock before and after the reaction/the iron content of the hydrocarbon feedstock is no less than 20.

In the present invention, the "difference in sulfur content in the hydrocarbon feedstock before and after the reaction" means the difference between the sulfur content (mass fraction) in the hydrocarbon feedstock and the sulfur content (mass fraction) in the reaction effluent.

In the present invention, the "difference in sulfur content in the hydrocarbon raw material before and after the reaction/iron content in the hydrocarbon raw material" means a ratio of the difference between the sulfur content (mass fraction) in the hydrocarbon raw material and the sulfur content (mass fraction) in the reaction effluent to the iron content (mass fraction) in the hydrocarbon raw material.

The invention utilizes the hydrogen supply performance of the hydrocarbon raw material, and controls the desulfurization reaction by adjusting the catalyst gradation and the process conditions, thereby providing a certain amount of hydrogen sulfide. The deferrization reaction is further promoted by hydrogen sulfide. Thereby simplifying the process of the prior art and creatively omitting hydrogen. In addition, after the gas phase material flow of hydrogen is omitted, the material flow speed in the reactor is reduced, the deposition of ferrous sulfide is facilitated, and the apparent deferrization rate is further improved. In the invention, after the hydrocarbon raw material passes through the deferrization reaction zone, the iron content in the obtained reaction effluent is obviously reduced, and the reaction effluent can directly enter any downstream hydrogenation device.

In one embodiment of the invention, the hydrogenation protective agent is filled by combining 1 to 4 hydrogenation protective agents, and the particle size of each hydrogenation protective agent is gradually reduced along the material flow direction. More preferably, the hydrodemetallization agent is filled by 1-4 hydrodemetallization agents in a combined mode, and the particle size of each hydrodemetallization agent is gradually reduced along the material flow direction.

In one embodiment of the invention, at least one fixed bed reactor is arranged in the deferrization reaction zone, at least one hydrogenation protective agent and at least one hydrogenation demetallization agent are sequentially graded in the fixed bed reactor along the material flow direction, the hydrogenation protective agent is filled by 2-4 hydrogenation protective agents in a combined mode, the particle size of each hydrogenation protective agent is gradually reduced along the material flow direction, the hydrogenation demetallization agent is filled by 2-4 hydrogenation demetallization agents in a combined mode, the particle size of each hydrogenation demetallization agent is gradually reduced along the material flow direction, and the particle size of the hydrogenation demetallization agent filled at the tail end part in the material flow direction is not more than 1.3 mm.

Preferably, the hydrodemetallization agent loaded in the end portion in the direction of flow has a particle size of not more than 1.1 mm.

The particle diameter in the present invention means the maximum value of the distance between any two points on the cross section of the catalyst.

In the invention, the loading volume fraction of the hydrogenation protective agent is 20-95% and the loading volume fraction of the hydrogenation demetallization agent is 5-80% on the basis of the whole catalyst in the deferrization reaction zone.

The grading scheme of the hydrogenation protective agent and the hydrogenation demetallization agent can be optimized according to the pore structure of the catalyst, the activity of the catalyst, the property of the raw material, the operation condition and the like.

In one embodiment of the invention, the hydrogenation protective agent comprises a carrier and an active component loaded on the carrier, wherein the carrier is one or more selected from alumina, silica and titanium oxide, the active component is selected from VIB group metals and/or VIII group metals, and the active component is 0.1-15% calculated by oxides based on the weight of the hydrogenation protective agent.

In one embodiment of the invention, the hydrogenation protective agent has a particle size of 0.5-50.0 mm and a bulk density of 0.3-1.2 g/cm ³ The specific surface area is 50 to 300m ² /g。

In one embodiment of the invention, the hydrodemetallization agent comprises a carrier and an active component loaded on the carrier, wherein the carrier is one or more selected from aluminum oxide, silicon oxide and titanium oxide, the active component is selected from VIB group metals and/or VIII group metals, and the active component accounts for 3-30% of the oxide by taking the weight of the hydrodemetallization agent as a reference.

In one embodiment of the invention, the hydrodemetallization agent has a particle size of 0.2 to 2.0mm and a bulk density of 0.3 to 0.8g/cm ³ The specific surface area is 100 to 250m ² /g。

In the present invention, the number of fixed bed reactors provided in the above-mentioned deferrization reaction zone is not particularly limited, and it is preferable to provide one fixed bed reactor.

The fixed bed reactor arranged in the deferrization reaction zone can be a downflow reactor or an upflow reactor. The downflow reactor refers to a reactor with a material flow flowing from top to bottom; the upflow reactor refers to a reactor with material flow flowing from bottom to top.

In the present invention, the iron content of the hydrocarbon feedstock is above 5. mu.g/g, preferably above 10. mu.g/g.

In one embodiment of the present invention, the sulfur content of the hydrocarbon raw material is not less than 0.1% by weight.

The hydrocarbon raw material is any iron-containing oil product, such as one or more selected from naphtha, diesel oil, wax oil, atmospheric residue, vacuum residue, deasphalted oil, coal tar and coal liquefaction heavy oil.

The reaction conditions of the deferrization reaction zone can be conventional conditions in the field, the reaction temperature of the deferrization reaction zone is 100-400 ℃, and the liquid hourly space velocity is 0.10-10.0 h ^-1 Preferably, the reaction temperature of the deferrization reaction zone is 200-370 ℃, and the liquid hourly space velocity is 0.6-6.0 h ^-1 。

The reaction effluent of the deferrization reaction zone goes to a downstream device. For example, a hydrogenation unit, generally needs to be mixed with hydrogen and then continuously reacted in a subsequent reactor, and the subsequent reactor can adopt a corresponding conventional catalyst grading method and conventional hydrogenation process conditions according to the requirements of the properties of the hydrocarbon raw material and the properties of products. The liquid phase stream may also be passed to other units, such as a catalytic cracking unit.

The two-phase deferrization method for the hydrocarbon raw material can remove most of iron-containing compounds in the hydrocarbon raw material, provide feeding with low iron content for a subsequent device, and ensure long-period operation of the subsequent device, thereby increasing the operation efficiency of the subsequent device and improving the economy.

Compared with the prior art, the method provided by the invention skillfully utilizes the hydrogen supply performance of the hydrocarbon raw material, and supplies the hydrogen sulfide obtained by the hydrocarbon desulfurization reaction to the deferrization reaction by controlling the reaction depth, so that a hydrogen system and a post-separation system can be omitted, and the investment cost and the operation cost of the device are greatly saved. In addition, after hydrogen is omitted, the material flow speed in the fixed bed reactor is reduced, the deposition of ferrous sulfide is facilitated, and the apparent deferrization rate is further improved.

Detailed Description

The process of the present invention is further illustrated below with reference to specific examples, but the invention is not limited thereto.

The catalysts used in the examples and comparative examples were catalysts of the residual oil hydrotreating series developed by the institute of petrochemical engineering science of china and produced by catalyst long distance division, and the catalyst grading used in each example and comparative example is shown in table 1, wherein RG series is a hydrogenation protecting agent, RDM series is a demetallizing agent, and the suffix of catalyst name indicates the particle size of the catalyst, e.g., RG-30B-3.0 represents the number of the hydrogenation protecting agent RG-30B, the particle size thereof is 3.0mm, and RDM-33-1.3 represents the number of the hydrogenation demetallizing agent RDM-33, the particle size thereof is 1.3 mm.

The raw materials used in the examples and comparative examples were the same, and their properties are shown in Table 3.

Examples 1 to 4

A single upflow bed type fixed bed reactor is arranged in the deferrization reaction zone, a hydrogenation protective agent and a hydrogenation demetalization agent are sequentially filled in the reactor from bottom to top, and the filling ratio of the catalyst is shown in Table 1. The hydrocarbon raw material enters from the bottom of the fixed bed reactor, and is sequentially contacted with the hydrogenation protective agent and the hydrogenation demetallization agent for reaction, and the reaction effluent is extracted from the top of the fixed bed reactor. The reaction conditions are shown in Table 2, and the properties of the starting materials and the properties of the reaction effluent are shown in Table 3.

It can be seen from the data in table 3 that the present invention removes most of the iron from the raw material and effectively protects the subsequent processing equipment, while controlling the reaction depth such that the difference in sulfur content between the hydrocarbon raw material before and after the reaction/the iron content in the hydrocarbon raw material is not less than 10.

Comparative example 1

A single upflow bed type fixed bed reactor is arranged in the deferrization reaction zone, a hydrogenation protective agent and a hydrogenation demetalization agent are sequentially filled in the reactor from bottom to top, and the filling ratio of the catalyst is shown in Table 1. The hydrocarbon raw material and hydrogen are mixed and then enter the fixed bed reactor from the bottom, and are sequentially contacted with the hydrogenation protective agent and the hydrogenation demetallization agent for reaction, and a reaction product is extracted from the top of the fixed bed reactor and separated into a liquid phase and a gas phase. The reaction conditions are shown in Table 2, and the properties of the starting materials and the properties of the liquid phase product are shown in Table 3.

From a comparison between comparative example 1 and example 4, it can be seen that, under the same catalyst grading and reaction conditions, although comparative example 1 is a hydrogenation reaction and has a higher sulfur removal content, the iron content of the liquid product is higher than that of the reaction effluent of example 4 because hydrogen increases the flow rate in the reactor and is not favorable for the deposition of ferrous sulfide.

Comparative example 2

The reactor set-up, stream set-up and catalyst grading loading were as in example 4, with the reaction conditions as shown in table 2 and the feedstock properties and reaction effluent properties as shown in table 3.

From a comparison of comparative example 2 and example 4, it can be seen that in comparative example 2, where the reactor set-up, stream set-up and catalyst grading loading were the same as in example 4, the difference in sulfur content in the hydrocarbon feedstock before and after the reaction/the iron content in the hydrocarbon feedstock was 5.5, with the resulting oil having a significantly higher iron content than the reaction effluent of example 4.

Therefore, compared with the prior art, the method skillfully takes the hydrocarbon raw material as the hydrogen source, and provides the hydrogen sulfide obtained by the hydrocarbon desulfurization reaction for the deferrization reaction by optimizing the catalyst gradation and the process conditions, thereby omitting a hydrogen gas system and a separation system, and obtaining the reaction effluent with low impurity content at low cost.

TABLE 1 catalyst grading Loading

TABLE 2 reaction conditions

TABLE 3 feed and reaction effluent Properties

Claims

1. A process for dual-phase deferrization of hydrocarbon raw material includes such steps as introducing the hydrocarbon raw material into deferrization reaction zone, sequentially contacting with hydrogenating protecting agent and hydrodemetalizing agent in the absence of hydrogen atmosphere for reaction to obtain the resultant with low S and Fe contents, and controlling the reaction depth to make the S content difference between raw hydrocarbon material and raw hydrocarbon material be not less than 10.

2. The process of claim 1 wherein the depth of the reaction is controlled so that the difference in the sulfur content of the hydrocarbon feedstock before and after the reaction is no less than 20 the iron content of the hydrocarbon feedstock.

3. The method of claim 1, wherein the hydrogenation protective agent is loaded by 1-4 hydrogenation protective agents, and the particle size of each hydrogenation protective agent is gradually reduced along the material flow direction.

4. The method of claim 1, wherein the hydrodemetallization agent is a combination of 1-4 hydrodemetallization agents, and the particle size of each hydrodemetallization agent decreases along the flow direction.

5. The method according to any one of claims 1 to 4, characterized in that the hydrogenation protective agent comprises a carrier and an active component loaded on the carrier, wherein the carrier is selected from one or more of aluminum oxide, silicon oxide and titanium oxide, the active component is selected from group VIB metals and/or group VIII metals, and the active component is 0.1-15% calculated by oxide based on the weight of the hydrogenation protective agent.

6. The method of claim 5, wherein the hydrogenation protective agent has a particle size of 0.5 to 50.0mm and a bulk density of 0.3 to 1.2g/cm ³ The specific surface area is 50 to 300m ² /g。

7. The method according to any one of claims 1 to 4, characterized in that the hydrodemetallization agent comprises a carrier and an active component loaded on the carrier, wherein the carrier is selected from one or more of aluminum oxide, silicon oxide and titanium oxide, the active component is selected from group VIB metals and/or group VIII metals, and the active component accounts for 3-30% of the oxide by weight of the hydrodemetallization agent.

8. The method of claim 7, wherein the hydrodemetallization agent has a particle size of 0.2 to 2.0mm and a bulk density of 0.3 to 0.8g/cm ³ The specific surface area is 100 to 250m ² /g。

9. The method according to claim 1 or 2, wherein the loading volume fraction of the hydrogenation protective agent is 20-95% and the loading volume fraction of the hydrogenation demetallization agent is 5-80% based on the whole catalyst in the deferrization reaction zone.

10. The process according to claim 1, characterized in that the iron content of the hydrocarbonaceous feedstock is higher than 5 μ g/g and the sulphur content is not less than 0.1 wt.%.

11. The method of claim 10, wherein the hydrocarbon feedstock is selected from one or more of naphtha, diesel, wax oil, long residue, vacuum residue, deasphalted oil, coal tar, and coal-to-liquid heavy oil.

12. The method according to claim 1, wherein the reaction temperature of the deferrization reaction zone is 100-400 ℃, and the liquid hourly space velocity is 0.10-10.0 h ^-1 。

13. The method of claim 12, wherein the reaction temperature of the deferrization reaction zone is 200-370 ℃, and the liquid hourly space velocity is 0.6-6.0 h ^-1 。