CN108587675B

CN108587675B - Heavy oil viscosity reducing method

Info

Publication number: CN108587675B
Application number: CN201810271695.5A
Authority: CN
Inventors: 宋立纲; 江笑; 朱亚尉; 宋金文
Original assignee: HIGH-TECH RESEARCH INSTITUTE NANJING UNIVERSITY LIANYUNGANG
Current assignee: HIGH-TECH RESEARCH INSTITUTE NANJING UNIVERSITY LIANYUNGANG
Priority date: 2018-03-29
Filing date: 2018-03-29
Publication date: 2020-06-09
Anticipated expiration: 2038-03-29
Also published as: CN108587675A

Abstract

The invention discloses a heavy oil viscosity reducing method, and belongs to the technical field of petroleum processing. Contacting heavy oil components with a catalyst of an alkaline carrier without silicon-aluminum elements in a viscosity reduction reactor, and carrying out cracking, isomerization, pour point depression and viscosity reduction under the conditions of no oxygen and/or reducing atmosphere, wherein the process conditions are that the reaction temperature is 300-550 ℃; the reaction pressure is 0.01-6.0 Mpa; the reaction time is 0.1-5.0 hours, the viscosity of the heavy oil can be obviously reduced, and the heavy oil can be used as a heavy oil fuel or a raw material for further processing and producing oil and gas products after the viscosity of the heavy oil is reduced. The invention utilizes the function of promoting polymerization and coke formation of the acid catalyst, and the function of inhibiting polymerization and coke formation of the alkaline catalyst, adopts the heavy oil viscosity-reducing cracking catalyst without the alkaline carrier of silicon and aluminum, and carries out viscosity reduction under the condition of no oxygen and/or reducing gas, so that the polymerization and coke formation tendency of reaction products can be reduced under the condition of deep viscosity reduction, and the operation severity can be reduced when the effect of deep viscosity reduction is achieved.

Description

Heavy oil viscosity reducing method

Technical Field

The invention relates to a heavy oil viscosity reducing method, and belongs to the technical field of petroleum processing.

Background

Heavy oil viscosity reduction is one of important technologies for heavy oil development and utilization. The early viscosity-reducing technology was a non-catalytic mild thermal conversion process of heavy oil, and its purpose was mainly to reduce the viscosity and pour point of heavy oil, to obtain qualified fuel oil with little or no light oil, or to provide raw material for further lightening of heavy oil. Visbreaking is still one of the important means for heavy oil processing due to simple process, low investment and good benefit. The visbreaking raw material is mainly vacuum residuum, and also can use topping crude oil, atmospheric residuum and heavy crude oil as raw material. The visbreaking products are mainly visbreaking gas, naphtha and residual oil, and the visbreaking residual oil can be further subjected to vacuum distillation to obtain visbreaking vacuum distillate oil and visbreaking vacuum residual oil.

The reaction temperature of visbreaking is usually between 380 and 490 ℃, the pressure is 0.3-1.0MPa, and the reaction time is several minutes to tens of minutes. According to the different processes of Visbreaking, the process is divided into Furnace tube Visbreaking (Furnace tube Visbreaking) and reaction tower Visbreaking (Furnace Column Visbreaking).

For a certain raw material, the conversion depth of visbreaking has a certain limit, and when the conversion depth exceeds the limit, the visbreaking residual oil can generate sediment due to phase separation, so that the requirement on the stability of the visbreaking residual oil can not be met, and if the conversion is further deepened, coking can be caused, so that the device can not normally operate. The early reaction tower is designed in a downflow mode, the start-up period is short, the coking in the reaction tower is serious, and the decoking of the reaction tower needs manual decoking, which takes manpower and time.

In a word, when the existing viscosity reduction technology is used for treating heavy and poor vacuum residue oil or heavy oil raw materials, the process flow is complex, the operation difficulty is high, more coke is generated during deep viscosity reduction, and a new viscosity reduction technology needs to be developed.

Disclosure of Invention

In order to better solve the problem of heavy oil viscosity reduction, the invention aims to provide a method for reducing the viscosity and the freezing point of heavy oil without blending or blending less gasoline and diesel oil fractions, and the method solves the technical problem that the heavy oil is deeply viscosity reduced and more coke is generated.

The technical scheme of the invention is as follows:

a heavy oil viscosity reduction method comprises the steps of contacting heavy oil components with a catalyst of an alkaline carrier without silicon-aluminum elements in a viscosity reduction reactor, and carrying out cracking, isomerization, pour point depression and viscosity reduction under the conditions of no oxygen and/or reducing atmosphere, wherein the process conditions are that the reaction temperature is 300-; reaction pressure (absolute pressure) 0.01-6.0MPa, preferably 0.2-2.0 MPa; the reaction time is 0.1-5.0 hours, the viscosity of the heavy oil can be obviously reduced, and the heavy oil can be used as a heavy oil fuel or can provide a raw material for further processing and producing oil and gas products after the viscosity of the heavy oil is reduced.

Further, the heavy oil component is one or more of atmospheric residue, vacuum residue, catalytic clarified oil, deasphalted oil, coal tar and super heavy oil.

Furthermore, the catalyst takes alkaline metal oxide without silicon-aluminum element as a carrier, takes nickel, molybdenum, cobalt, tungsten or the combination thereof as an active component, and takes at least one of nonmetal acidic elements such as fluorine, phosphorus, boron and the like as an auxiliary agent.

Further, the catalyst is prepared by the following steps: (1) preparing corresponding solution from at least one or more of soluble calcium salt, magnesium salt, zinc salt, ferric salt and manganese salt, adding polyethylene glycol, drying at 80-150 ℃ for 8-24 h, preferably at 110 +/-10 ℃ for 8-20 h, roasting at 400-600 ℃ for 10-24 h, preferably at 450-550 ℃ for 12-20h, and preparing the alkaline catalyst carrier without silicon-aluminum elements; (2) soluble nickel salt, molybdenum salt, cobalt salt, tungsten salt or their combination as active component, adding at least one of non-metal acidic elements such as soluble fluoride, phosphide, boride, etc. to prepare solution; (3) soaking a catalyst carrier in the solution, and performing soaking, drying, roasting and cooling under the condition of normal pressure to obtain the catalyst, wherein the shape of the catalyst can be strip, granular or powder, the soaking temperature is room temperature-90 ℃, preferably 20-60 ℃, the drying temperature is 60-200 ℃, preferably 80-160 ℃, the roasting temperature is 200-800 ℃, preferably 300-600 ℃, wherein the mass ratio of the active component of the catalyst to the carrier is 2-25 wt%, and the mass ratio of the auxiliary agent to the catalyst carrier is 0.2-5 wt%.

Further, the oxygen-free and/or reducing atmosphere refers to an atmosphere of steam, nitrogen, hydrogen, steam + hydrogen, nitrogen + hydrogen, syngas (H + CO), and preferably an atmosphere of hydrogen, steam + hydrogen, nitrogen + hydrogen, syngas (H + CO), and the like.

Further, the viscosity reduction reactor can adopt a fluidized bed reactor, a suspension bed reactor, a boiling bed reactor, a slurry bed reactor, a moving bed reactor or a combination thereof.

Further, the products after the viscosity reduction reaction can be fractionated as required and cut into dry gas, liquefied gas, gasoline, diesel oil and heavy oil fractions; the heavy oil fraction can be taken as a product out of a device, used as a fuel, or used as a raw material for catalytic cracking, hydrocracking, delayed coking and the like, and can also be taken as a visbreaking raw material to enter a visbreaking reactor for cracking reaction. As fuel oil component, light components <165 ℃ are usually cut off.

Compared with the prior art, the invention utilizes the function of promoting polymerization to generate coke of the acid catalyst, and the function of inhibiting polymerization to generate coke of the alkaline catalyst, and adopts the heavy oil viscosity-reducing cracking catalyst without the alkaline carrier of silicon and aluminum, and carries out viscosity reduction under the condition of no oxygen and/or reducing gas, so that firstly, the polymerization coke-generating tendency of reaction products can be reduced under the condition of deep viscosity reduction, and secondly, the operation severity can be reduced when the deep viscosity reduction effect is achieved, namely, a better viscosity reduction effect can be obtained under lower reaction temperature and hydrogen pressure.

Detailed Description

Example 1

Preparation of basic catalyst support

300 g of magnesium nitrate and polyethylene glycol (polyethylene glycol is added to promote the active components of the catalyst to be uniformly distributed, increase the surface area of the catalyst and increase the number of active centers, and the active centers are decomposed and converted into water and CO in the roasting process₂And removed) 50 g of the active component, completely dissolved in deionized water, fully stirred and mixed, and dried at 110 ℃ (the main purpose of drying is to remove water in the solution, active components in the solution are adsorbed on the inner and outer surfaces of a carrier and are in a solid state, and the physical properties are not changed. Chemical change can occur after roasting, salts are decomposed into oxides) for 8 hours, the obtained product is placed in a roasting furnace, the temperature is uniformly raised to 600 ℃ at the temperature raising speed of 10 ℃, the temperature is kept for 24 hours under the condition of introducing oxygen, and the temperature is uniformly lowered to room temperature, so that the basic catalyst carrier is obtained. Crushing the particles of the catalyst carrier to a size of less than 150 meshes and a specific surface area of 260m²G, pore volume 0.35cm³(ii)/g, the distribution of the most probable pore diameter is 5-80 nm. The catalyst appeared as a white powder. The carrier of the catalystBody ZT.

Example 2

Preparation of basic catalyst

1. Weighing 150.0 g of catalyst precursor ZT, dissolving nickel nitrate, ammonium molybdate and boric acid in deionized water to prepare a mixed aqueous solution, preheating the aqueous solution to 60 ℃, adding the prepared catalyst carrier, impregnating, continuously stirring for 1.5 hours, standing for 12 hours, heating to 120 ℃ after impregnation, drying, and drying at constant temperature of 120 ℃ for 12 hours; after drying, uniformly heating to 500 ℃, roasting for 8 hours, and cooling to room temperature to obtain the catalyst CAT-C of the alkaline carrier. MoO in catalyst₃The content of (B) was 10.6 wt%, the content of NiO was 3.6 wt%, and the content of B was 2.5 wt%.

Example 3

Evaluation of hydro application of heavy oil + catalyst

The evaluation device of the catalyst is a 1000ml stainless steel kettle type magnetic sealing stirring device, and the catalyst CAT-C25 g, the heavy oil 500 g, the fraction at 380-600 ℃, the condensation point 86 ℃, the total sulfur content 2.65 wt%, and the viscosity at 100 ℃ of 920mm are taken²Adding a catalyst and heavy oil into a reactor, replacing a reaction system for 3 times by using nitrogen after sealing and pressure testing are qualified, starting to heat up at the heating rate of 10 ℃/min to 150 ℃, starting a stirring device at the rotating speed of 400rpm, supplementing hydrogen to the reaction system to 3.0MPa, continuously uniformly heating to 450 ℃, controlling the reaction pressure to be 6.0MPa, stabilizing for 3 hours, cooling to 60 ℃, reducing the pressure to normal pressure, taking out a reaction product, and fractionating, wherein the gas product is 2.1 wt%, the gasoline fraction is 12.3 wt%, the diesel fraction is 24.8 wt%, the heavy oil fraction is 60.8 wt%, the freezing point is-6 ℃, and the viscosity is 28mm at 100 DEG C²/s。

Examples 4 to 8

Catalysts of examples 4-8 the same catalysts as in example 3 and comparative example 2 were a silica-alumina U-Y molecular sieve

The visbreaking heavy oil has the characteristics of raw material properties, the density of the visbreaking heavy oil at 20 ℃ is 1.0991g/cm3, the kinematic viscosity of the visbreaking heavy oil at 100 ℃ is 1304.5mm2/s, the condensation point is 65 ℃ and the sulfur content is 1.92 weight percent. The evaluation method was the same as in example 3, and the evaluation conditions and results are shown in Table 1.

Comparative example 1, the raw materials and evaluation method of example 4, 3, no catalyst, evaluation conditions and results are shown in Table 1.

Comparative example 2, the raw materials and 4, catalyst for silicon aluminum molecular sieve, evaluation method and 3, evaluation conditions and results are shown in Table 1.

As can be seen from Table 1, the catalyst and the method of the present invention can greatly reduce the condensation point and the viscosity of the heavy oil, and the viscosity-reduced heavy oil can be used as a heavy oil fuel without or with less light oil components; at a higher visbreaking depth, compared with the silicon-aluminum molecular sieve catalyst, the catalyst containing no silicon-aluminum alkaline carrier has more polymerization coke formation in the visbreaking reaction of the silicon-aluminum molecular sieve catalyst, and the polymerization coke formation in the visbreaking reaction of the catalyst containing no silicon-aluminum alkaline carrier is not obvious.

The above examples are merely illustrative of the present invention and are not intended to limit the embodiments of the present invention. Many different forms of modifications or variations may be made by those skilled in the art.

Claims

1. A heavy oil viscosity reduction method comprises the steps of contacting heavy oil components with a catalyst of an alkaline carrier without silicon-aluminum elements in a viscosity reduction reactor, and carrying out cracking, isomerization, pour point depression and viscosity reduction under the conditions of no oxygen and/or reducing atmosphere, wherein the reaction temperature is 300-550 ℃; the reaction pressure is 0.01-6.0 Mpa; the reaction time is 0.1 to 5.0 hours;

the catalyst takes alkaline metal oxide without silicon-aluminum element as a carrier, takes nickel, molybdenum, cobalt, tungsten or the combination thereof as an active component, and takes at least one of fluorine, phosphorus and boron as an auxiliary agent;

wherein, the mass ratio of the active components of the catalyst to the carrier is 2-25%, and the mass ratio of the auxiliary agent to the catalyst carrier is 0.2-5%.

2. The method of claim 1, wherein the reaction temperature is 380-450 ℃; the reaction pressure is 0.2-2.0 MPa.

3. The method of claim 1, wherein the heavy oil component is one or more of long residue, short residue, catalytic decant oil, deasphalted oil, coal tar, and extra heavy oil.

4. The process of claim 1 or 3, wherein the catalyst is prepared by: (1) preparing corresponding solution from at least one or more of soluble calcium salt, magnesium salt, zinc salt, ferric salt and manganese salt, adding polyethylene glycol, drying at 80-150 ℃ for 8-24 h, and roasting at 400-600 ℃ for 10-24 h to prepare the alkaline catalyst carrier without silicon-aluminum elements; (2) soluble nickel salt, molybdenum salt, cobalt salt, tungsten salt or the combination of the nickel salt, the molybdenum salt, the cobalt salt and the tungsten salt are used as active components, and at least one of fluoride, phosphide and boride is added to prepare solution; (3) and (3) soaking a catalyst carrier in the solution obtained in the step (2), and performing soaking, drying, roasting and cooling under the condition of normal pressure to obtain the catalyst, wherein the soaking temperature is room temperature to 90 ℃, the drying temperature is 60 to 200 ℃, and the roasting temperature is 200-800 ℃, wherein the mass ratio of the active component of the catalyst to the carrier is 2 to 25 percent, and the mass ratio of the auxiliary agent to the catalyst carrier is 0.2 to 5 percent.

5. The method of claim 1, wherein the oxygen-free and/or reducing atmosphere is steam, nitrogen, hydrogen, steam + hydrogen, nitrogen + hydrogen, syngas H₂+ CO atmosphere.

6. The method of claim 1, wherein the oxygen-free and/or reducing atmosphere is hydrogen, steam + hydrogen, nitrogen + hydrogen, syngas H₂+ CO atmosphere.

7. The method of claim 1, wherein the reaction product is used as a heavy oil fuel or to provide a feedstock for further processing to produce oil and gas products.