Heavy oil countercurrent hydrogenation upgrading process method

Abstract

The invention discloses a heavy oil countercurrent hydrogenation upgrading process method, and relates to a heavy oil upgrading process method, which realizes independent or simultaneous operation of a plurality of tubular reactors connected in parallel through a switching valve, and realizes continuous efficient production of catalytic hydrogenation, catalytic desulfurization, catalytic denitrification, catalytic deoxidation and catalyst regeneration. When in use, the method has outstanding characteristics, a countercurrent hydrogenation process is adopted to replace a traditional forward hydrogenation process, the contact area of reactants is increased, and the reaction efficiency is improved; the fixed bed reactor adopts a single-tube multi-bed design, and simultaneously realizes upgrading reactions such as catalytic cracking, catalytic hydrogenation, catalytic desulfurization, catalytic denitrification, catalytic deoxidation and the like; meanwhile, the device can realize continuous production of independent regeneration of the single-tube catalyst, greatly improves the working efficiency, can realize high-efficiency hydrogenation quality improvement of heavy oil such as waste tire pyrolytic oil, oil sand pyrolytic oil, coal pyrolytic oil, waste engine oil, residual oil, wheel engine oil and the like, and has a very strong application prospect.

Description

Technical Field

[0001] The present invention relates to a process method for upgrading heavy oil, and particularly to a countercurrent hydro-upgrading process method for heavy oil. Background Art

[0002] With the increasingly strict environmental protection requirements, the sulfur content limit in fuel oil is becoming more and more stringent. As an important product in the petroleum processing process, heavy oil has a high sulfur content. Traditional hydrodesulfurization methods face many challenges when dealing with heavy oil. Therefore, developing an efficient hydrodesulfurization method for heavy oil has important practical significance.

[0003] Heavy oil, as an important fraction in the petroleum refining process, has complex characteristics such as high boiling point, high viscosity, high aromatic content, and high sulfur content. Traditional hydrodesulfurization processes have exposed many intractable problems when dealing with heavy oil. On the one hand, due to the large and complex molecular structure of heavy oil, the sulfides in it exist in various forms such as thiophene and its derivatives, which greatly increases the mass transfer resistance of the desulfurization reaction, resulting in the desulfurization efficiency of traditional hydrodesulfurization methods never reaching the expected standard and being difficult to meet the current fuel standards.

[0004] The forward hydroprocessing is a relatively traditional process mode for heavy oil hydrodesulfurization. The feedstock oil and hydrogen flow in the same direction, enter together from the reactor inlet, and gradually flow through the catalyst bed to carry out reactions. Its advantages are that the process flow is relatively simple, the equipment layout and operation are relatively easy to control, and the upfront investment cost is relatively low. However, during the process of hydrogen and feedstock oil passing through the catalyst bed, there will be a phenomenon that hydrogen or feedstock oil passes through the catalyst bed alone, which will lead to insufficient reaction and thus reduce the reaction efficiency. Moreover, as the reaction progresses, the concentration of reactants gradually decreases, while the concentration of reaction products continues to increase. In the second half of the reactor, the high-concentration products will inhibit the further deepening of the reaction, resulting in the desulfurization effect being difficult to reach a higher level, which will also lead to a reduction in reaction efficiency.

[0005] Countercurrent hydrogenation exhibits unique advantages, especially in terms of increasing the reaction contact area and enhancing the reaction efficiency. During countercurrent hydrogenation, the feedstock oil enters from the top of the reactor, while hydrogen is injected from the bottom of the reactor. This way, hydrogen and the feedstock oil maintain the maximum contact area in the catalytic bed, which means that reactant molecules have more opportunities to collide and react, and the active sites of the catalyst can be utilized more fully, thereby significantly improving the reaction efficiency. Secondly, this reverse flow pattern makes the concentration gradient distribution in the entire reaction process more reasonable. At the bottom of the reactor, fresh high-concentration hydrogen contacts the heavy oil that is about to complete the reaction and has a relatively low sulfur content, ensuring deep desulfurization; at the top of the reactor, the newly introduced high-sulfur feedstock oil meets the hydrogen that has risen from the bottom, participated in part of the reaction but is still active, and the two quickly start to react. In this way, in all regions of the reactor, there can always be a high concentration difference between reactants, which can also improve the reaction efficiency.

[0006] To solve the above problems, researchers have carried out a large amount of research work on this technology for decades.

[0007] As disclosed in Chinese Patent CN119020068A, using a two-stage series hydrogenation process, the inferior heavy oil undergoes mild hydrothermal cracking through the first hydrogenation reaction. After the reaction, the product undergoes two gas-liquid separations to obtain light fractions, middle fractions, and heavy fractions. The light fractions and middle fractions undergo hydrorefining through the second hydrogenation reaction. The refined product undergoes two more gas-liquid separations, and the liquid-phase products obtained from the two-stage hydrogenation reactions are combined and fractionated to finally obtain high-quality hydrogenated products.

[0008] Again, as disclosed in Chinese Patent CN111375401B, the carrier of the catalyst of the present invention is an alumina-activated carbon composite carrier. Compared with the existing alumina carrier, it is beneficial to the dispersion of the active metal components, weakens the interaction with the active components, makes its sulfidation more complete, and is easy to form more high-hydrogenation active centers, making the catalyst have higher hydrogenation activity.

[0009] Chinese Patent CN108018074A proposes a heavy oil hydrotreating method for improving the utilization rate of the catalyst. After the heavy oil feedstock is mixed with hydrogen, it first passes through a hydrotreating pretreatment zone to carry out hydrodemetallization and partial desulfurization reactions; the reaction effluent enters the hydrotreating reaction zone to carry out hydrodesulfurization and hydrodenitrogenation reactions; among them, the reaction temperature in the hydrotreating pretreatment reaction zone is higher than that in the hydrotreating reaction zone. This invention mainly removes most of the metals in the material by carrying out the reaction in the hydrotreating pretreatment reaction zone at a higher temperature.

[0010] Chinese Patent CN103059927A discloses a hydrotreating method for heavy oil products. The heavy oil products and hydrogen are successively introduced into a plurality of serially connected hydroreactors and come into contact with a plurality of hydrocatalyst beds in the hydroreactors. According to the flow direction of the heavy oil products, the reactors include a first hydroreactor, a second hydroreactor, and subsequent hydroreactors after the second reactor. When the pressure drop in the first hydroreactor reaches the upper limit of the pressure drop or a hot spot is formed in the reactor, the heavy oil products and hydrogen are directly introduced from the second hydroreactor and flow through the second hydroreactor and subsequent reactors in sequence. Summary of the Invention

[0011] The object of the present invention is to provide a countercurrent hydro-upgrading process method for heavy oil. This method adopts a countercurrent hydrogenation method. By using the countercurrent hydrogenation process, the contact area of heavy oil during the reaction is increased, and the desulfurization efficiency is improved.

[0012] The object of the present invention is achieved through the following technical solutions: A countercurrent hydro-upgrading process method for heavy oil, the method includes the process of introducing hydrogen in a countercurrent manner, and the steps are as follows: Hydrogen is added to the reactor, and hydrogen provides pressure for the reaction system in the reactor; When the pressure in the reactor system reaches the required value, the heavy oil raw material is sprayed into the heavy oil gasification furnace cavity from the feed port. The oil droplets are quickly gasified at high temperature, and the heavy oil, asphaltene, ash residue, etc. that are difficult to gasify are preliminarily separated in the heavy oil gasification furnace; The gasified heavy oil gas enters the fixed bed reactor. First, it passes through the quartz sand heat conduction bed layer, which can effectively buffer the scouring effect of the oil gas on the catalyst, and then passes through the hydro-upgrading catalyst bed layer to achieve hydro-upgrading, desulfurization, denitrification, and deoxidation; The reaction product enters the quench reactor for gas-liquid separation treatment. The liquid product is discharged through the upgraded oil outlet. The gas product first passes through the tail gas processor and then enters the hydrogen booster, and continues to circulate in the reactor; When the sulfur and nitrogen content indexes in the upgraded heavy oil cannot meet the requirements, catalyst regeneration treatment is carried out in a single tube, and multiple fixed bed reaction tubes are operated separately.

[0013] The described countercurrent hydro-upgrading process method for heavy oil, the heavy oil includes one or a mixed oil of oil shale pyrolysis oil, oil sand pyrolysis oil, coal pyrolysis oil, waste oil, residue oil, and turbine oil.

[0014] The described heavy oil countercurrent hydro-upgrading process method, where the catalytic hydro-upgrading is carried out under the conditions of a reaction temperature of 280 - 450 °C, a gas pressure of 1 - 10 Mpa, a liquid hourly space velocity of 0.3 - 10.0 h⁻¹, and a gas / oil volume ratio of 100 - 1000:1 for hydrodesulfurization, hydrodenitrogenation, hydrodeoxygenation, and olefin saturation reactions.

[0015] The advantages and effects of the present invention are: By adopting the countercurrent hydro-upgrading process, the contact area between the feedstock oil and hydrogen is increased, the pressure difference in the reactor is ensured, and the reaction efficiency is improved; The fixed-bed reactor is easy to operate, has a high hydro-upgrading efficiency, can be continuously produced, and can achieve catalytic cracking and catalytic hydrogenation; Quality-improving reactions such as catalytic desulfurization, catalytic denitrogenation, and catalytic deoxygenation are carried out simultaneously, and continuous production is uninterrupted; This process can achieve continuous operation with independent regeneration of single-tube catalysts, greatly improving work efficiency; This process is reasonably designed and operates reliably in terms of technical implementation. Especially by using the heavy oil catalytic hydro-upgrading process, high-efficiency hydro-upgrading of heavy oils such as oil sand pyrolysis oil, coal pyrolysis oil, waste engine oil, residue oil, and turbine oil can be achieved, increasing the contact area between reactants and maintaining a scientific pressure difference in the reactor, thereby improving the reaction efficiency. Since this process can enhance the catalytic efficiency, it can save the cost of desulfurization and quality improvement after heavy oil fractionation, and has strong application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the application of the heavy oil countercurrent hydro-upgrading process of the present invention; Figure 2 It is a schematic diagram of the structure of the fixed-bed reactor in the heavy oil countercurrent hydro-upgrading process of the present invention.

[0017] Among them, the components are: hydrogen inlet 1, heavy oil inlet 2, heavy oil vaporizer 3, fixed-bed reactor 4, quench reactor 5, product oil tank 6, hydrogen pressurizer 7, upgraded heavy oil outlet 8, heavy oil 9, heating furnace 10, quartz sand bed 11, hydro-upgrading catalyst bed 12, upgraded heavy oil 13. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention will be described in detail below with reference to the embodiments shown in the drawings.

[0019] Taking an application of a heavy oil countercurrent hydro-upgrading process as an example, the process flow and operation steps of the present invention are clarified.

[0020] From the attached Figure 1It can be seen that the process design of the heavy oil hydro-upgrading of the present invention includes a hydrogen inlet 1, a heavy oil inlet 2, a heavy oil gasifier 3, a fixed bed reactor 4, a quench reactor 5, a product oil tank 6, a hydrogen pressurizer 7, and a upgraded heavy oil outlet 8. Among them, the hydrogen inlet 1 is located at the top of the hydrogen pressurizer 7, the heavy oil inlet 2 is located at the top of the heavy oil gasifier 3, the heavy oil gasifier 3 is connected to the fixed bed reactor 4, and a quartz sand bed 11 ( Figure 2 ), and a hydro-upgrading catalyst bed 12 ( Figure 2 ). The fixed bed reactor 4 is connected to the quench reactor 5, and the product oil tank 6 is located at the lower end of the quench reactor 5. After separation, the liquid product is discharged through the upgraded pyrolysis oil outlet 8, and the gaseous product, the recycled hydrogen, enters the pipeline through the hydrogen pressurizer 7 to complete the cycle.

[0021] When the present invention is applied to a countercurrent hydro-upgrading process for heavy oil, it includes the following steps: 1) Hydrogen raw materials enter the heavy oil gasifier 3 from the hydrogen inlet 1 at a rated rate and in accordance with the designed route, and provide pressure for the reaction system; 2) When the pressure in the reactor system reaches the required value, the heavy oil raw materials are sprayed into the cavity of the heavy oil gasifier 3 from the feed port 2. The oil droplets are quickly gasified at high temperature, and the asphaltene, ash residue, etc. that are difficult to gasify are preliminarily separated in the heavy oil gasifier 3; 3) The gasified heavy oil gas enters the fixed bed reactor 4, first passes through the quartz sand heat-conducting bed 11 ( Figure 2 ), which can effectively buffer the scouring effect of the oil gas on the catalyst, and then passes through the hydro-upgrading catalyst bed to achieve the purpose of hydro-upgrading, desulfurization, denitrification, and deoxidation; 4) The reaction products enter the quench reactor 5 for gas-liquid separation treatment, and the liquid products are discharged through the upgraded oil outlet 8; 5) When the sulfur, nitrogen, and other content indicators in the upgraded heavy oil cannot meet the requirements, the catalyst is regenerated in a single tube, and multiple fixed bed reaction tubes can be operated independently. Example 1

[0022] This example is the application of the catalytic hydro-upgrading process for Panjin oil shale oil, such as Figure 1As shown in the figure, the design of the heavy oil hydro-upgrading process includes a hydrogen inlet 1, a heavy oil inlet 2, a heavy oil gasifier 3, a fixed bed reactor 4, a quench reactor 5, a product oil tank 6, a hydrogen pressurizer 7, and a upgraded heavy oil outlet 8. Hydrogen raw material enters the heavy oil gasifier 3 from the hydrogen inlet 1 at a rated rate and according to the designed route, and provides pressure for the reaction system. When the pressure in the reactor system reaches the required value, the heavy oil raw material is sprayed into the cavity of the heavy oil gasifier 3 from the feed inlet 2. The oil droplets are rapidly gasified at high temperature, and the asphaltene, ash residue, etc. that are difficult to gasify are preliminarily separated in the heavy oil gasifier 3, and then enter the fixed bed reactor 4 through the heavy oil gasifier 3. First, it passes through the quartz sand heat conduction bed layer 11( Figure 2 ), which can effectively buffer the scouring effect of the oil and gas on the catalyst. Then, it passes through the hydro-upgrading catalyst bed layer to achieve the purpose of hydro-upgrading, desulfurization, denitrification, and deoxygenation. The reaction products enter the quench reactor 6 for gas-liquid separation treatment. The liquid products are discharged through the upgraded pyrolysis oil outlet 8, and the gas product, recycled hydrogen, passes through the hydrogen pressurizer 7 to complete the cycle.

[0023] The operating conditions for catalytic hydro-upgrading are: reaction temperature 360 °C, gas pressure 4 Mpa, liquid hourly space velocity 4 h -1 and gas / oil volume ratio 200. The desulfurization efficiency reaches 83%, the denitrification efficiency reaches 63%, and the oil yield is 91%. Example 2

[0024] This example is the application of the catalytic hydro-upgrading process for residue pyrolysis oil. As Figure 1 shown in the figure, the design of the heavy oil hydro-upgrading process includes a hydrogen inlet 1, a heavy oil inlet 2, a heavy oil gasifier 3, a fixed bed reactor 4, a quench reactor 5, a product oil tank 6, a hydrogen pressurizer 7, and a upgraded heavy oil outlet 8. Hydrogen raw material enters the heavy oil gasifier 3 from the hydrogen inlet 1 at a rated rate and according to the designed route, and provides pressure for the reaction system. When the pressure in the reactor system reaches the required value, the heavy oil raw material is sprayed into the cavity of the heavy oil gasifier 3 from the feed inlet 2. The oil droplets are rapidly gasified at high temperature, and the asphaltene, ash residue, etc. that are difficult to gasify are preliminarily separated in the heavy oil gasifier 3, and then enter the fixed bed reactor 4 through the heavy oil gasifier 3. First, it passes through the quartz sand heat conduction bed layer 11( Figure 2 ), which can effectively buffer the scouring effect of the oil and gas on the catalyst. Then, it passes through the hydro-upgrading catalyst bed layer to achieve the purpose of hydro-upgrading, desulfurization, denitrification, and deoxygenation. The reaction products enter the quench reactor 6 for gas-liquid separation treatment. The liquid products are discharged through the upgraded pyrolysis oil outlet 8, and the gas product, recycled hydrogen, passes through the hydrogen pressurizer 7 to complete the cycle; The operating conditions for catalytic hydro-upgrading are: reaction temperature 385 °C, gas pressure 3 Mpa, liquid hourly space velocity 2 h -1The gas / oil volume ratio is 600, the desulfurization efficiency reaches 92%, the denitrification efficiency reaches 77%, and the oil yield is 94%. Example 3

[0025] This example is the application of the catalytic hydro-upgrading process for oil sand pyrolysis oil. As Figure 1 shown, the design of the heavy oil hydro-upgrading process includes a hydrogen inlet 1, a heavy oil inlet 2, a heavy oil gasifier 3, a fixed bed reactor 4, a quench reactor 5, a product oil tank 6, a hydrogen pressurizer 7, and a upgraded heavy oil outlet 8. The hydrogen raw material enters the heavy oil gasifier 3 from the hydrogen inlet 1 at a rated rate and follows the designed route, and provides pressure for the reaction system. When the pressure in the reactor system reaches the required value, the heavy oil raw material is sprayed into the cavity of the heavy oil gasifier 3 from the feed port 2. The oil droplets are rapidly gasified at high temperature, and the asphaltenes, ash residues, etc. that are difficult to gasify are preliminarily separated in the heavy oil gasifier 3 and enter the fixed bed reactor 4 through the heavy oil gasifier 3. First, it passes through the quartz sand heat-conducting bed layer 11( Figure 2 ), which can effectively buffer the scouring effect of the oil and gas on the catalyst. Then it passes through the hydro-upgrading catalyst bed layer to achieve the purpose of hydro-upgrading, desulfurization, denitrification, and deoxidation. The reaction products enter the quench reactor 6 for gas-liquid separation treatment. The liquid products are discharged through the upgraded pyrolysis oil outlet 8, and the gaseous product recycle hydrogen passes through the hydrogen pressurizer 7 to complete the recycle.

[0026] The operating conditions for catalytic hydro-upgrading are: reaction temperature 380 °C, gas pressure 3 Mpa, liquid hourly space velocity 2 h -1 and gas / oil volume ratio 600, the desulfurization efficiency reaches 94%, the denitrification efficiency reaches 76%, and the oil yield is 95%.

Claims

1. A process for upgrading heavy oil by countercurrent hydroprocessing, characterized in that, The method includes a process of introducing hydrogen in a reverse flow, and the steps are as follows: (1) Add hydrogen into the reactor, and the hydrogen provides pressure for the reaction system in the reactor; (2) When the pressure in the reactor system reaches the required value, spray the heavy oil raw material into the heavy oil gasification furnace cavity from the feed port. The oil droplets are rapidly gasified at high temperature, and heavy oil, asphaltene, ash residue, etc. that are difficult to gasify are preliminarily separated in the heavy oil gasification furnace; (3) The gasified heavy oil gas enters the fixed-bed reactor. First, it passes through the quartz sand heat-conducting bed layer, which can effectively buffer the scouring effect of the oil gas on the catalyst, and then passes through the hydro-upgrading catalyst bed layer to achieve hydro-upgrading such as hydrogenation, desulfurization, denitrification, and deoxygenation; (4) The reaction products enter the quench reactor for gas-liquid separation treatment. The liquid products are discharged through the upgraded oil outlet. The gas products first pass through the tail gas processor and then enter the hydrogen pressurizer and continue to circulate in the reactor; (5) When the sulfur and nitrogen content indicators in the upgraded heavy oil cannot meet the requirements, single-tube catalyst regeneration treatment can be carried out, and multiple fixed-bed reaction tubes can be operated separately. That's all.

2. The heavy oil countercurrent hydro-upgrading process method according to claim 1, wherein, The heavy oil mentioned above includes one or a mixture of oil shale pyrolysis oil, oil sand pyrolysis oil, coal pyrolysis oil, waste engine oil, residue oil, and turbine oil.

3. A heavy oil countercurrent hydro-upgrading process method according to claim 1, characterized in that, The catalytic hydro-upgrading is carried out under a reaction temperature of 280 - 450 °C, a gas pressure of 1 - 10 Mpa, a liquid hourly space velocity of 0.3 - 10.0 h⁻¹, and a gas / oil volume ratio of 100 - 1000:1 for hydrodesulfurization, hydrodenitrification, hydrodeoxygenation, and olefin saturation reactions.

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