JPS6119676B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method of subjecting petroleum crude oil and various heavy hydrocarbons derived from petroleum crude oil to a thermal decomposition reaction and demetallizing them. Heavy hydrocarbons (hereinafter sometimes simply referred to as heavy oil) usually contain sulfur compounds, nitrogen compounds, high molecular weight organometallic complexes containing nickel and vanadium as metal components, and n-pentane-insoluble asphalt. Substances (asphaltene)
It is included. However, these impurities contained in heavy oil pose a major hindrance to the use of heavy oil as a fuel, and also as a raw material for chemical processing. In particular, metals such as vanadium, nickel, and iron contained in heavy oil are deposited on the catalyst when the heavy oil is hydrotreated, resulting in a sharp decrease in the activity of the catalyst.
Therefore, in order to utilize heavy oil as a more valuable liquid hydrocarbon oil, sulfur, metals and asphaltenes are removed, and the boiling point is adjusted to a distillable range, that is, 550°C or less. It is necessary to make it highly useful. Conventionally, methods for improving the quality of heavy oil containing impurities as described above can be broadly classified into thermal cracking methods and hydrocracking methods. Thermal cracking methods are typified by delade cokers, fluid cokers, etc., and produce gas, distillate oil, and coke, but in this case, there are differences in whether the reaction is carried out in a coking drum or in a fluidized bed. However, both methods have the disadvantage that a large amount of coke with low added value is produced. On the other hand, the hydrocracking method involves reacting at high pressure and high temperature in the presence of a catalyst, and methods such as boiling bed, fixed bed, and moving bed have been proposed, but this method produces high-quality hydrogen-rich products. Although oil is obtained, it has the disadvantage that a large amount of hydrogen is consumed, and since a catalyst is used, metals in the heavy oil are deposited on the catalyst, resulting in a significant deterioration of catalyst activity. There is a problem in that the cost required for the catalyst is large. The inventors of the present invention have conducted intensive research to overcome the drawbacks of the conventional methods as described above, reduce hydrogen consumption, and reduce catalyst costs. The hydrothermal decomposition reaction is carried out in the presence of a hydrogen donor without substantially using hydrogen gas to produce a small amount of pitch-like material, and to produce a small amount of pitch-like material that is contained in heavy oil. 0.1 to 40% by weight, preferably 0.5 to 20% by weight of metals such as vanadium and nickel.
When deposited, this metal-containing pitch-like substance exhibits a catalytic effect and significantly accelerates the thermal decomposition reaction of heavy oil, an unexpected result.
The present inventors have discovered that metals contained in heavy oil are efficiently deposited and concentrated in pitch-like substances, thereby achieving effective demetallization of heavy oil, and have completed the present invention. That is, according to the present invention, heavy hydrocarbons are treated at a reaction temperature of 400 to 550°C and a reaction pressure of 10 to 100 Kg/ ^cm2.
Under the conditions of G, an organic compound that liberates hydrogen under these conditions is used as a hydrogen donor for the reaction system, and is a pitch-like substance obtained by thermal decomposition of hydrocarbons, containing vanadium and/or nickel. The process involves carrying out a hydrothermal decomposition reaction using a substance as a catalyst to lighten the heavy oil, and depositing the metals contained in the heavy oil into the pit-like substance. A benzene-insoluble pitch-like substance containing 0.1 to 40% by weight of metals is separated from the decomposition product oil, and this is recycled to the reaction system, and the benzene-insoluble pitch-like substance is added to the reaction system at a rate of at least 5% by weight. A method for demetallizing heavy hydrocarbons is provided. In the present invention, heavy hydrocarbons include sulfur compounds and nitrogen compounds, as well as metals such as vanadium, nickel, and iron, of which at least 10% by volume is heated to 550°C or higher. It has a boiling point, and its specific gravity at 20℃ is 0.93.
These hydrocarbons include petroleum crude oil, heavy oil extracted from tar sands, atmospheric distillation residue oil, vacuum distillation residue oil,
Includes crude oil and various other heavy oils commonly referred to as "black oil." Such heavy oil usually has a content of 100 ppm or more, and in many cases,
Contains 150ppm or more of metals. The method of the present invention is to simultaneously lighten the heavy oil and demetalize it by hydropyrolyzing the heavy oil under special conditions. uses a compound that liberates hydrogen under the reaction conditions (referred to as a hydrogen donor in the present invention) as a hydrogen source in the reaction system without using hydrogen gas, and as a catalyst, it is obtained by thermal decomposition reaction of hydrocarbons. It is necessary to use a pitch-like material containing vanadium, nickel, and/or iron. The hydrogen donor used in the present invention may be any substance that releases hydrogen under the reaction conditions used in the present invention, that is, at 400 to 550°C. and others. Examples of alcohols include methanol, ethanol, propanol, benzyl alcohol,
-Primary alcohols, secondary alcohols, tertiary alcohols, allyl-type unsaturated alcohols such as phenylethanol, 3-fluorobenzyl alcohol, cyclohexanol, 2,3-butanediol, 2-propanol, 2-butanol, etc. Alcohols with less steric hindrance donate hydrogen more easily. As an example of hydrocarbons, tetralin is the most common, but other examples include cyclohexane, 1.6
-dimethyltetralin, cyclohexene, 1.3
- or 1,4-cyclohexadiene, octarine, 6-methyltetraline, anthracene oil, creosote oil and the like. Examples other than the alcohols and hydrocarbons mentioned above include indoline, pyrrolidine, tetrahydroquinoline, piperidine, dioxane, tetrahydrofuran, isopropylamine, N-methylpyrrolidone, formic acid, aromatic aldehydes, aliphatic saturated carbonyl compounds, and amines. , ether, etc. In the present invention, when the pyrolysis reaction of heavy oil is carried out in the presence of the hydrogen donor described above, the heavy oil is thermally decomposed or thermally altered and hydrogenated by hydrogen from the hydrogen donor, resulting in good quality light oil. In addition, sulfur compounds and nitrogen compounds are also removed by hydrogenolysis. It is desirable to regenerate and recycle the hydrogen donor used in the present invention after the reaction, so the basic skeleton remains as it is without being decomposed in the reaction system and supplies only hydrogen, such as tetralin or cyclohexane. It is advantageous to use those which are susceptible to dehydrogenation and hydrogenation reactions such as These substances are dehydrogenated and converted into unsaturated compounds in the reaction system, but after the reaction, they are easily regenerated into the original hydrogen-donating substance by hydrogenation and recycled back into the reaction system. and can be used. The amount of the hydrogen donor added in the present invention is determined mainly by its hydrogen donating ability, but may also be determined depending on the amount to be present in the reaction system in liquid form and the desired degree of hydrorefining of heavy oil. Furthermore, since the hydrogen donor also serves as a diluent for heavy oil, it can be appropriately determined depending on the viscosity and mixing/stirrability of the desired mixing system. Industrially, 10 to 1000 parts by weight per 100 parts by weight of heavy oil,
Preferably, it is applied in a proportion of 50 to 500 parts by weight. When demetallizing heavy oil according to the present invention, the most important thing, as described above, is to have a pitch-like substance containing a metal such as vanadium or nickel that acts as a catalyst in the reaction system.
Such a material can be prepared separately by thermally decomposing hydrocarbon oil to create a pitch-like material, and adding an appropriate amount of a metal component such as vanadium or nickel that has catalytic activity to this material, but in the present invention, Taking advantage of the fact that when heavy oil undergoes a thermal decomposition reaction in the presence of the hydrogen donor described above, a pitch-like substance containing metal is produced, heavy oil is added to the reaction system in advance in a predetermined pitch. It is preferable to carry out a thermal decomposition reaction by circulating the produced oil until such a substance is produced and accumulated, and to prepare it in the reaction system. The amount of this pit-like substance in the reaction solution is 1 to 50% by weight, preferably 5 to 30% by weight, and the metal content is
It is 0.1% by weight or more, usually 0.5 to 40% by weight, preferably 1 to 20% by weight. In addition, the pitch-like substance as used in the present invention is a product obtained by thermal decomposition of heavy oil or other hydrocarbons, with a melting point of about 200°C or higher, and which is substantially soluble in benzene. It means something that doesn't. This compound is presumed to be a polycyclic aromatic compound having a structure identical to or similar to the core of asphaltene. The reaction temperature in the present invention is selected from the range of 380 to 550°C. If it is lower than 380°C, the decomposition reaction will be slow, which is undesirable. On the other hand, if it exceeds 550°C, not only will coke precipitation increase significantly, but also This is not preferable because it causes excessive weight reduction accompanied by gasification. Furthermore, since it is preferable to obtain a reaction solution in which the hydrogen donor and heavy oil are uniformly dissolved in a liquid state, the reaction pressure is selected within a range where the hydrogen donor exists in a liquid state. Generally, it is selected from the range of 15 to 100 Kg/cm ² G. It is clear in principle that any atmosphere can be used as long as it is gaseous under the reaction conditions as the atmosphere for forming the pressurization, but generally hydrogen, nitrogen, steam, Paraffin-based light hydrocarbons and gas produced by decomposition of hydrocarbons are used. The reaction time can be determined appropriately in relation to the reaction temperature, but
Usually 120 minutes or less is sufficient. When heavy oil is hydropyrolyzed according to the present invention, the catalytic effect of the metal-containing pit substance present in the reaction system significantly accelerates the hydropyrolysis reaction, and the heavy oil is efficiently lightened. , At the same time, hydrorefining of heavy oil is achieved. Moreover, since this pitch-like material exhibits excellent adsorption ability for metals contained in heavy oil, efficient metal removal from heavy oil can be achieved. Furthermore, it is advantageous that when heavy oil is pyrolyzed under the above-mentioned conditions, the amount of pitty material produced is small, and this material contains a high concentration of metals and has catalytic activity. , on the contrary, without interfering with the reaction,
Accelerates the reaction and significantly enhances the demetalization effect. According to a preferred embodiment of the present invention, heavy oil is mixed with at least one hydrogen donor selected from cyclohexane, cyclohexene, tetralin, decalin, anthracene and derivatives thereof, or 20% by weight of at least one of these hydrogen donors. The metal content of the resulting product is 0.5 to 0.5%.
40% by weight of the metal-containing pitch-like substance and the dehydrogenated hydrogen donor were separated, and the metal-containing pitch-like substance was recycled to the reaction system as it was, while
A method is provided in which the dehydrogenated hydrogen donor is regenerated into the original hydrogen donor by hydrogenation using hydrogen gas, and then recycled to the reaction system. According to the present invention, since a liquid hydrogen donor is used as a direct hydrogen source in the reaction system without using hydrogen gas, the hydrogen usage efficiency is significantly increased compared to the case where hydrogen gas is used. The method of the present invention can be carried out either batchwise or continuously, and excess pitch-like substances accumulated in the reaction system can be discharged out of the system either continuously or intermittently. can. Next, the present invention will be explained in more detail with reference to Examples. Comparative Example Heavy crude oil having the properties shown in Table 1 below and commercially available tetralin as a hydrogen donor were mixed in a 1:1 (weight ratio)
Use the mixture as raw material, and 100g of it is
It was installed in a 200ml electromagnetic stirring autoclave, the rotation speed was 500rpm, the air in the autoclave was replaced with hydrogen, and the temperature was raised to 430℃ at a rate of 10℃/min, the pressure reached 90Kg/cm ² G, The reaction was allowed to proceed in this state for 120 minutes. During the course of this reaction, formation and accumulation of a pitch-like substance was observed. Table 2 shows the properties of the produced oil obtained as a result of the reaction.

【table】

[Table] * Example 1 containing tetralin The produced oil obtained in Comparative Example 1 was filtered, and the obtained benzene-insoluble pitch-like substance was added at a ratio of 5% by weight to the heavy crude oil shown in Comparative Example. The reaction was carried out in the same manner as in the comparative example. Table 3 shows the properties of the resulting oil. The demetalization rate in this produced oil increased from 55% in the comparative example to 70%. Furthermore, compared to the comparative example, the specific gravity of the produced oil also decreased, indicating that thermal decomposition was further promoted.Furthermore, despite the addition of benzene-insoluble pitch-like substances, the newly produced benzene-insoluble matter 2.5% by weight
Therefore, it is recognized that the cyclic use of benzene-insoluble pitch-like substances does not have a particular effect on the by-product of pitch-like substances. In addition, instead of recycling the benzene-insoluble pitch-like substance separated from the produced oil, when recycling the distillation residue obtained by distilling the produced oil as it is, it is possible to use a coke-like benzene-insoluble pitch-like substance containing a lot of carbonaceous matter. Significant amounts of substances are produced as by-products, and the catalytic effect that is seen when adding benzene-insoluble pitch-like substances separated from the produced oil cannot be obtained.

[Table] Example 2 of insoluble matter in SUS 2 A mixture of heavy crude oil and tetralin in a weight ratio of 1:1 shown in the comparative example was mixed with hydrogen gas into a continuous reactor made of SUS316 with a diameter of 1 inch and a length of 3 m. At the same time, a benzene-insoluble pitch-like substance was separated from the resulting product oil and circulated. In this case, at the start of the reaction, 5% by weight of the benzene-insoluble pitch-like substance shown in Example 1 (vanadium content 0.95% by weight) is added to the raw material mixed oil in advance, and the reaction is carried out. After the reaction reached steady state, the addition was stopped and the pits separated from the product oil were recycled. In addition, when carrying out this reaction, the reaction temperature is 415℃, the reaction pressure is 30Kg/cm ² G, the superficial velocity is 1, the raw material mixed oil supply rate is 240c.c./hour, and the hydrogen supply rate is 72/hour. Set. As a result of the above-mentioned reaction, the amount of circulating pitch-like material is
After 120 hours, the amount of vanadium reached 5.5% by weight and after 240 hours, it reached 5.8% by weight, and the amount of vanadium contained in the circulating pitch material was 2.3% by weight after 120 hours.
After 240 hours, the amount increased to 3.5% by weight.

Claims (1)

[Claims] 1. Heavy hydrocarbons are treated at a reaction temperature of 400 to 550°C and a reaction pressure of 10 to 100 Kg/cm ² G, and an organic compound that releases hydrogen under these conditions is used to donate hydrogen to the reaction system. A benzene-insoluble pitch-like substance obtained by the thermal decomposition reaction of hydrocarbons and containing vanadium and/or nickel is used as a catalyst to carry out a hydrogen thermal decomposition reaction. The process consists of lightening the heavy hydrocarbons and depositing the metals contained in the heavy hydrocarbons into the pit-like substance, and removing 0.1 to 40% by weight of the metals from the resulting thermal decomposition product oil. A method for producing heavy hydrocarbons, which is characterized in that a benzene-insoluble pitch-like substance containing the substance is separated and recycled to the reaction system, so that the benzene-insoluble pitch-like substance is present in the reaction system in a proportion of at least 5% by weight. Demetallization method. 2. The method according to claim 1, wherein the reaction pressure is adjusted using at least one selected from hydrogen, nitrogen, steam, paraffinic light hydrocarbons, and decomposed gas of hydrocarbons. 3. Claim 1, in which at least one selected from cyclohexane, cyclohexene, tetralin, decalin, anthracene, and derivatives thereof, or a mixture containing at least one of these in an amount of 20% by weight or more is used as a hydrogen donor. Method of Section 2.