JP2931969B2 - Method for desulfurizing coal, heavy oil, crude oil, orinoco tar, polymer using acid catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a desulfurization method for removing a compound containing sulfur from a compound containing sulfur based on a bond between carbon and carbon.

[0002]

2. Description of the Related Art When fuel is used for combustion, sulfur contained in the fuel is converted into sulfur oxides and is discharged as an exhaust gas together with carbon dioxide and water vapor. This sulfur oxide is an air pollutant and has an undesired effect on living environments such as humans, animals, plants, and various buildings. For this purpose, desulfurization methods and desulfurization equipment have been developed. Among fossil fuels, gasoline, diesel oil, and other compounds with relatively low boiling points are subjected to hydrogenation treatment in the presence of NiMo or CoMo catalysts, and sulfur contained in these is removed as a sulfur compound. Used.
If the boiling point is higher than the above, carbon precipitates on the surface of the catalyst or the catalyst is poisoned.Thus, it is difficult to perform the treatment using the catalyst. Removal of sulfur from has been performed.
Although the sulfur in coal was removed by a physical method called coal separation, it was for inorganic sulfur with a different specific gravity, and most of organic sulfur was used as fuel without treatment, and these were found in exhaust gas. The removal of combustion products of organic sulfur has been carried out. Orinoco tar is a reserve-rich carbon-containing organic resource mainly produced in Latin America, but it has a high sulfur content (4-5
%) Is hindering use, and is not even used. By the way, flue gas desulfurization treatment for treating exhaust gas requires a large-scale facility, and also requires a great deal of operation cost. And small boilers are sometimes used without being installed in flue gas desulfurization equipment. For these reasons, there has been a demand for a method for removing a sulfur compound from a fuel such as heavy oil or crude oil, coal, orinoco tar containing a component having a high boiling point. In recent years, sulfur-containing polymers have attracted attention as heat-resistant resins and high-performance resins, and have been actively used. However, no specific method for treating and recycling waste has yet been developed.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to convert a compound based on a carbon-carbon bond containing sulfur into a compound at a relatively low temperature and without using hydrogen in the presence of a catalyst. It is an object of the present invention to provide a method for removing a compound containing sulfur by treating under a low pressure condition.

[0004]

According to the present invention, a compound based on a carbon-carbon bond and containing sulfur therein is converted into trifluoromethanesulfonic acid, hydrogen fluoride,
And in the presence of a catalyst consisting of hydrogen fluoride and boron trifluoride and a liquid hydrocarbon, at a temperature of
A desulfurization method contained in the compound is provided, wherein the sulfur compound is separated by treating at a pressure of ８8 MPa.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION An object to be treated according to the present invention is a compound based on the bond between carbon and carbon and containing sulfur therein. This object is coal, heavy oil, crude oil, orinoco tar, sulfur-containing polymer or polymer composition.

[0006] Coal is mainly composed of polycyclic aromatic structural parts, chain-like and cyclic aliphatic structural parts having different degrees of condensation, and these structural parts are directly or oxygen-containing and sulfur-containing. Alternatively, a structure in which they are bonded to each other via a nitrogen-containing group is employed. Known bond states of sulfur include thiophene type, sulfide type, disulfide type, and oxidized type. In addition, in some cases, sulfur in the form of an inorganic compound that does not participate in bonding is contained. The desulfurization method of the present invention can be applied to any type of coal regardless of the sulfur content in the coal. For example, mekinensa charcoal known for containing a large amount of sulfur (carbon: 63.
(2%, hydrogen: 6.1%, sulfur: 12.0%) can be an object of the present invention, and the desulfurization reaction of the present invention can be sufficiently performed. In order to advance the desulfurization reaction, the coal is mixed with a liquid hydrocarbon. At that time, it is necessary to make sufficient contact with the liquid hydrocarbon, and for that purpose, it is necessary to have a fine granular form.
Generally, it is necessary for the diameter of the grains to be between 0.1 and 1.0 mm, preferably between 0.1 and 0.25 mm. In order to obtain the particle diameter, treatment such as pulverization classification of coal is performed. Sulfur not involved in the bond contained in coal is
It is preferable to remove them prior to the desulfurization reaction. For this purpose, treatment with an inorganic acid is performed. As the inorganic acid for this purpose, nitric acid, hydrochloric acid, sulfuric acid or the like can be used, but it is preferable to use nitric acid in order not to remain on the surface of the coal after the treatment.

[0007] Petroleum is a mixture of hydrocarbons having different boiling points. These mixtures are mainly composed of liquid hydrocarbons and contain small amounts of sulfur compounds, oxygen compounds, nitrogen compounds and the like. In petroleum refining, naphtha, gasoline gas oil, heavy oil, coal tar and the like are separated and used by distillation. Among them, heavy oils such as heavy oils are difficult to desulfurize by hydrogenation in the presence of a usual catalyst. Such a fraction having a relatively high boiling point or a mixture containing the same is an object of the present invention. Sulfur contained in petroleum is combined with carbon to form a compound like coal.

Orinocotal is a high-viscosity carbon-containing liquid polymer produced in Latin America. Similar to coal and petroleum, it contains a large amount of hydrocarbon compounds. However, because of its high sulfur content, it is one of the resources not yet used as a fuel. Usually, 4 to 5% by weight of a sulfur component is contained. Sulfur contained in orinoco tar, like coal, combines with carbon to form a compound. In the treatment, a pretreatment such as hydrodesulfurization is performed.

[0009] Examples of the sulfur-containing polymer or the sulfur-containing polymer compositions include polymers, such as polyphenylene _et Nirensurufu _i de, and polythiophene. Further, those obtained by crosslinking a polymer by vulcanization are also included. When these polymers or polymer compositions are solid, it is necessary to carry out the treatment after pulverizing and classifying the particles to have a particle size in the range of 0.1 to 1.0 mm as in the case of coal. is there.

In the desulfurization method of the present invention, trifluoromethanesulfonic acid, hydrogen fluoride and a mixture of hydrogen fluoride and boron trifluoride are used as a catalyst. In the desulfurization method of the present invention, these catalysts can be used in a gas or liquid state. The reaction is initiated and continued by confining it in a gaseous state during the reaction or by adding it in liquid form to existing liquid hydrocarbons. The amount of catalyst used is
Generally, it is used in the following range. For coal, 1K coal
The range is 1 to 10 kg, preferably 5 to 6 kg per g. In the case of heavy oil, 0.5 to 1 kg of heavy oil
It is in the range of 7 kg, preferably 5-6 kg. In the case of crude oil, 0.5 to 7 kg, preferably 5 kg / kg of crude oil.
６6 kg. In the case of a sulfur-containing polymer or a sulfur-containing polymer composition, 1 to 8 kg, preferably 4 to 6 kg per 1 kg of the sulfur-containing polymer or sulfur-containing polymer composition.
Kg range. If it is less than these ranges, the effect may not be obtained. In addition, when it exceeds these ranges, there is no special effect and it is not economical. It is considered that these acid catalysts release a proton into the reaction system during the reaction, and this easily bonds with sulfur having a lone electron pair to form a protonated compound. Thereafter, the thiol-type compound that is likely to be generated by cleavage of the protonated compound is easily hydrogenated and cleaved by another proton to form gaseous hydrogen sulfide, which can be discharged out of the reaction system.

[0011] The desulfurization method of the present invention is carried out in the presence of a liquid hydrocarbon. Liquid hydrocarbons are hydrocarbons that are liquid at room temperature and atmospheric pressure, that is, hydrocarbons having a boiling point of room temperature or higher at room temperature and atmospheric pressure. Liquid hydrocarbons include aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbons such as pentane, hexane and octane; alicyclic hydrocarbons such as cyclopentane and cyclohexane; hydrocarbons containing condensed rings; and coal. And products obtained by desulfurizing heavy oil, crude oil, orinoco tar, and sulfur-containing polymer. The used amount of the liquid hydrocarbon is generally used in the following range. In the case of coal, 1 kg per 1 kg of coal.
The range is 5 to 3 kg, preferably 1.7 to 2.0 kg. In the case of heavy oil, 0.5-2.
0 kg, preferably in the range of 1.5 to 1.7 kg.
In the case of crude oil, 0.5 to 2.0 kg per 1 kg of crude oil,
Preferably 1.5-1. . It is in the range of 7 kg. In the case of the sulfur-containing polymer or the sulfur-containing polymer composition, 1.5 kg per 1 kg of the sulfur-containing polymer or the sulfur-containing polymer composition.
To 3 kg, preferably 1.7 to 2.0 kg. If it is less than these ranges, the effect may not be obtained. In addition, when it exceeds these ranges, there is no special effect and it is not economical.

[0012] The desulfurization method of the present invention has a temperature of 50-250.
C. and a pressure of 2 to 8 MPa. If it is less than this condition, the desulfurization reaction may not progress, and if it exceeds this condition, there is no particular change from the case below this,
Not economic. In the desulfurization reaction, the sulfur bonded to the carbon changes into gaseous hydrogen sulfide compounds such as hydrogen sulfide, sulfide, thiophene, and the like. Then, these gaseous sulfur compounds are separated from the reaction product. Also, by blowing nitrogen gas or the like into the reaction product taken out of the reactor after the reaction, the catalyst can be separated from the reaction product. Then, the recovered catalyst is neutralized and then discarded. The reaction product from which sulfur has been removed as a sulfur compound by the desulfurization reaction is a polymer containing liquefied carbon, and can be used as a fuel, or can be further treated with hydrogen or the like to produce a chemical reaction raw material or fuel. You can do it. After the desulfurization reaction, after removing the catalyst from the obtained desulfurization product, or in some cases without removing the catalyst, it can be returned to the liquid hydrocarbon and recycled.

[0013]

Next, the contents of the present invention will be described as examples. The content of the present invention is not limited to these. Examples 1 to 7, Comparative Example 1 Mekinensa coal which is a high sulfur content coal produced in Spain (carbon:
63.2, hydrogen: 6.1, sulfur: 12.0 wt%) desulfurization 100 g of mekinensa charcoal is ground to a particle size of 0.25 mm or less, and then treated with a 25 vol% nitric acid aqueous solution to remove inorganic sulfur.
96 g of sample coal (carbon: 53.8, hydrogen: 4.9, sulfur: 8.7%) was obtained. As catalysts, 6.78 g of trifluoromethanesulfonic acid, 5.46 g of hydrogen fluoride, and hydrogen fluoride and boron trifluoride (5.46 g and 1.22 g) were added to 2 ml of toluene and stirred sufficiently. Each of them was mixed with coal and filled into a 100 cc Hastelloy autoclave.
The reaction was performed under a hydrogen-free pressure at 150 to 250 ° C and 2.6 to 6.6 MPa. After the reaction, the autoclave was stirred at 90 to 150 ° C., nitrogen was blown in at 100 ml / min, hydrogen fluoride and boron trifluoride were separated from the product, and transferred to a recovery device directly connected to the autoclave. In the case of trifluoromethanesulfonic acid, after neutralization with an aqueous solution of sodium carbonate, the product was separated from the neutralized product by a filtration method. Quantitative analysis of organic sulfur is based on Heraeus CHN- according to JIS M8813-1976.
Performed gravimetrically using 0-PAPID. In addition, morphological analysis of organic sulfur in the product obtained from Mekinensa charcoal was performed using photoelectron spectroscopy XPS. The results of the desulfurization rate of Mekinensa coal are shown in Table 1 together with the organic sulfur morphological analysis (MQ
2, 4-6). The same processing was performed except that no catalyst was used, and the results are shown in Table 1 as Comparative Example 1 (MQ
1). The desulfurization rate of the product was 15-67%. On the other hand, when reacted with no solvent using hydrogen fluoride, the desulfurization rate was 15%
Increased. When isopentane was used with hydrogen fluoride, the desulfurization rate increased slightly to 22% (MQ3). The desulfurization rate when using trifluoromethanesulfonic acid is 3
5%, and the desulfurization rate is lower than that using hydrogen fluoride (MQ6). Focusing on the change in the form of sulfur, MQ
In -2, sulfide disappeared and thiophene increased remarkably. This suggests that the sulfide is converted into thiophene by ring closure and aromatization without solvent. In the case of no solvent, it can be seen that desulfurization is mainly caused by a decrease in sulfur oxide. Addition of isopentane resulted in a slight decrease in sulfide, and almost all of the sulfide disappeared when toluene was used.
It can be seen that the high desulfurization rate of 52% is mostly due to the reduction of sulfur oxides and sulfides. Next, when toluene was used and a mixed acid of hydrogen fluoride and boron trifluoride was used, the desulfurization rate further increased to 57%. And MQ-4
The difference from (hydrogen fluoride alone) is that not only sulfide but also thiophene is reduced. Mixed acids exhibiting high acidity have been reported to cause ion hydrogenation reactions, but it is believed that thiophene was hydrogenated and converted to sulfide. The above results are shown in FIG. This cyclic sulfide is treated at a reaction temperature of 250 ° C. or higher in the presence of the catalyst of the present invention, whereby
It is cleaved and thus can be removed. Further, desulfurization can be further performed using a conventionally used desulfurization catalyst such as NiMo or CoMo. When the reaction was attempted at 150 ° C and 250 ° C, the desulfurization rate at 150 ° C was 38%, but reached 250% at 69 ° C (NQ7,8). However, the product obtained at 250 ° C. has low solubility in solvents and is found to be unsuitable when used as a liquid fuel and when treated in other processes. From these facts, it is understood that it is optimal to use hydrogen fluoride and boron trifluoride at a reaction temperature of 200 ° C.

Examples 8 to 11 Heavy oil (bitumen, carbon: 85.4%, hydrogen: 8.91%, sulfur:
2.5% by weight), orinoco tar (carbon: 83.7%, hydrogen: 10.2,
(Sulfur: 4.0% by weight), polyphenylene sulfide and the like were treated in the same manner as in Example 1 to carry out a desulfurization reaction. Table 1 shows the reaction conditions of each sample. When heavy oil (bitumen), orinocotal, polyphenylene sulfide, etc. were reacted in the presence of toluene using hydrogen fluoride as a catalyst, a desulfurization rate of 30-40% was obtained as shown in Table-2. Was done.
Bitumen and orinocotal could not be analyzed by XPS measured in high vacuum due to the large amount of volatile components remaining. Therefore, the form of sulfur is not clear, but it is considered that this desulfurization rate is probably due to the form of sulfur. On the other hand, 70% of sulfur was removed from the high-molecular-weight polyphenylene sulfide in which all the sulfur was a sulfide type.

[0015]

[Table 1]

From the above, it was clarified that when each sample was treated with toluene as an aromatic solvent in the presence of hydrogen fluoride, most of the sulfide or sulfur oxide was removed at 200 ° C. Trifluoromethanesulfonic acid also exhibited a similar effect, although the desulfurization rate was inferior, and it was confirmed that hydrogen fluoride / boron trifluoride was also effective in removing thiophene. These super-strong acid catalysts are effective for organic resources such as heavy oil and orinoco tar irrespective of coal. It has also been found that the method can be applied to sulfur removal treatment related to the disposal of sulfur-containing polymers whose production volume will continue to increase in the future.

[0017]

According to the desulfurization method of the present invention, it is possible to desulfurize organic resources such as coal, heavy oil, orinoco tar and waste plastics containing sulfur under mild reaction conditions without using hydrogen.

[Brief description of the drawings]

FIG. 1 is a view showing an organic sulfur form in a desulfurization product of mekinensa coal.

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁶ identification code FI C08J 11/18 ZAB B01D 53/36 D (58) Field surveyed (Int.Cl. ⁶ , DB name) C10G 29/10 C10G 31 / 06 C10L 9/00 B01D 53/86 C08J 11/10 C08J 11/18

Claims (6)

(57) [Claims] 1. A catalyst comprising trifluoromethanesulfonic acid, hydrogen fluoride, hydrogen fluoride and boron trifluoride, and a compound comprising a carbon-carbon bond containing sulfur therein. 50 to 2 in the presence of hydrogen
A method for desulfurizing sulfur contained in a compound, comprising treating at a temperature of 50 ° C. and a pressure of 2 to 8 MPa to separate a sulfur compound. 2. A compound based on a carbon-carbon bond and containing sulfur therein, comprising a compound comprising trifluoromethanesulfonic acid, hydrogen fluoride and a catalyst comprising hydrogen fluoride and boron trifluoride. 50- in the presence of hydrocarbons
A method in which a treatment is performed at a temperature of 250 ° C. and a pressure of 2 to 8 MPa to separate a sulfur compound and a catalyst, and then a part of a product is added to a liquid hydrocarbon to continue the treatment. 3. A desulfurization method according to claim 1 or 2, wherein the compound containing sulfur as a carbon is a coal. 4. A desulfurization method according to claim 1 or 2, wherein the compound containing sulfur as a carbon and containing sulfur therein is heavy oil or crude oil. 5. A desulfurization method characterized in that the compound based on the bond between carbons according to claim 1 or 2 and containing sulfur therein is orinocotal. 6. A desulfurization method characterized in that the compound based on the bond between carbon and carbon according to claim 1 or 2 and containing sulfur therein is a polymer.