JP2011219538A - Method for reforming heavy oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for reforming a heavy oil by simply removing sulfur components contained in the heavy oil under mild conditions.SOLUTION: The method for reforming a heavy oil is characterized by removing sulfur components contained in the heavy oil by mixing a saturated or supersaturated electrolyte solution and the heavy oil. By this method, sulfur components contained in a heavy oil such as A-heavy oil, B-heavy oil or C-heavy oil can be effectively removed without using supercritical water to which a metal or metal catalyst which reacts with water in the presence of alkali and generates hydrogen, has been added.

Description

  The present invention relates to a method for reforming heavy oil. More specifically, the present invention relates to a method for reforming heavy oil by simply removing sulfur components contained in heavy oil under mild conditions.

  Heavy oil is important as a resource to meet future energy demand, but in order to effectively use heavy oil as fuel, it is necessary to modify it by removing the sulfur component contained in it. As is well known. Therefore, various methods for desulfurization of heavy oil have been proposed so far, but in recent years, methods utilizing the characteristics of supercritical water have attracted attention. For example, in Patent Document 1, a metal such as iron that generates hydrogen by reacting with water in the presence of alkali is added to the reaction system, and thiophene contained in heavy oil is decomposed by hydrothermal reaction under supercritical water conditions. A method has been proposed. In addition, a method using a hydrodesulfurization reaction under supercritical water conditions in which a metal catalyst such as a NiMo catalyst is added to the reaction system has also been proposed (see, for example, Non-Patent Document 1). However, since the critical temperature of water is 374 ° C. and the critical pressure is 218 atm, there is a restriction that desulfurization of heavy oil using supercritical water requires equipment that can withstand high temperature and pressure. Further, in the methods described in Patent Document 1 and Non-Patent Document 1, it is necessary to add a metal or a metal catalyst that generates hydrogen by reacting with water in the presence of an alkali to the reaction system, so that the treatment process is complicated. become.

JP2002-219350

Masafumi Ajiri, “Supercritical water reforming of heavy oil”, Journal of the Japan Institute of Energy, Vol. 88, No. 3, March 2009, pp. 172-175

  Therefore, an object of the present invention is to provide a method for reforming heavy oil by simply removing sulfur components contained in heavy oil under mild conditions.

  As a result of intensive studies in view of the above points, the present inventors have developed a metal or metal catalyst that reacts with water in the presence of alkali to generate hydrogen when an electrolyte solution having a saturated concentration or higher and heavy oil are mixed. It has been found that sulfur components contained in heavy oil can be effectively removed even under normal temperature and normal pressure conditions without adding or using supercritical water.

The method for reforming heavy oil of the present invention based on the above knowledge is to remove the sulfur component contained in heavy oil by mixing a saturated or supersaturated electrolyte solution and heavy oil as claimed in claim 1. Features.
Further, the heavy oil reforming method according to claim 2 is characterized in that in the heavy oil reforming method according to claim 1, stirring is performed under conditions of normal pressure to normal temperature to 200 ° C.
The reforming method according to claim 3 is the reforming method according to claim 1 or 2, wherein the mixing ratio of the saturated or supersaturated electrolyte solution and heavy oil is 20: 1 to 1:20 (volume ratio). It is characterized by that.

  According to the present invention, it is possible to provide a method for reforming heavy oil by simply removing sulfur components contained in heavy oil under mild conditions.

It is a graph which shows the time transition of the desulfurization rate of the heavy oil inject | poured into the stainless steel pipe | tube in Example 1. FIG. It is a graph in Example 2 same as the above. It is a graph in Example 3 same as the above. It is a graph in Example 4 same as the above. It is a graph in Example 5 similarly. It is a graph in Example 6 similarly. It is a graph in Example 7 similarly.

  The method for reforming heavy oil according to the present invention is characterized in that a sulfur component contained in heavy oil is removed by mixing a saturated or supersaturated electrolyte solution with heavy oil. According to the present invention, heavy oil such as A heavy oil, B heavy oil, C heavy oil, etc., without adding a metal or metal catalyst that generates hydrogen by reacting with water in the presence of alkali or using supercritical water. The sulfur component contained in can be effectively removed.

  Examples of the electrolyte for preparing a saturated or supersaturated electrolyte solution include alkaline electrolytes such as sodium hydroxide, lithium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, magnesium hydroxide, and calcium hydroxide. Hydroxides may be used, but neutral electrolytes such as lithium chloride, potassium chloride, rubidium chloride, sodium chloride, cesium chloride, magnesium chloride, calcium chloride and other metal chlorides, lithium sulfate, potassium sulfate, rubidium sulfate Use of metal sulfates such as sodium sulfate, cesium sulfate, magnesium sulfate, calcium sulfate, metal carbonates such as lithium carbonate, potassium carbonate, rubidium carbonate, sodium carbonate, cesium carbonate, magnesium carbonate, calcium carbonate, etc. Against Desirable from the point of view of gender. The valence of the electrolyte is not particularly limited, but divalent is preferable to monovalent in that the desulfurization effect is excellent. It should be noted that the electrolyte solution having a saturated or supersaturated concentration may be prepared by dissolving a necessary amount of electrolyte for obtaining a saturated or supersaturated concentration at the treatment temperature in water.

  Mixing of the electrolyte solution with saturated or supersaturated concentration and heavy oil is performed, for example, with stirring (for example, a stirrer of 100 rpm to 100 rpm) at normal pressure (pressure not applied or reduced pressure) at normal temperature (eg, 5 ° C. to 35 ° C.) to 200 ° C. (By rotating at 2000 rpm) is desirable in that desulfurization can be performed effectively in a short time without consuming a large amount of energy. It should be noted that desulfurization can be performed even at room temperature and normal pressure, and the method of the present invention is a metal or metal that reacts with water in the presence of an alkali so far to generate hydrogen. This is fundamentally different from the method using supercritical water to which a metal catalyst is added. The mixing ratio of the saturated or supersaturated electrolyte solution and heavy oil is preferably 20: 1 to 1:20 (volume ratio), for example. If the amount of heavy oil is too small relative to the electrolyte solution having a saturated or supersaturated concentration, the desulfurization efficiency may be inferior. On the other hand, if the amount of heavy oil is excessive, desulfurization may not be performed sufficiently. The stirring and mixing time may be, for example, 10 minutes to 100 hours. After the treatment, desulfurized heavy oil can be recovered by performing oil-water separation. Further, the recovered heavy oil may be desulfurized again by the method of the present invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is limited to the following description and is not interpreted.

Example 1: Investigation using sodium hydroxide as electrolyte (part 1)
Total length: 15cm x outer diameter: 1cm x inner diameter: 0.7cm stainless steel tube (SUS316), 20N (regulation: same as below) sodium hydroxide aqueous solution (saturated concentration solution at 150 ° C) about 5g and heavy oil (heavy oil A) Inject about 0.4 g (volume ratio: about 9: 1), put the rotor, close the screw-type lid, immerse it in an oil bath on a hot stirrer, and heat the rotor to 1500 rpm at 150 ° C. for 48 hours. The sample in the stainless steel tube was stirred and mixed at normal pressure. The time course of the desulfurization rate of heavy oil injected into the stainless steel pipe is shown in FIG. FIG. 1 also shows the results when a 1N aqueous sodium hydroxide solution and a 10N aqueous sodium hydroxide solution were used in place of the 20N aqueous sodium hydroxide solution, respectively. In addition, the desulfurization rate (%) of heavy oil was calculated | required by the numerical formula of (1-sulfur component content wt% after a process / sulfur component content wt% before a process) x100. The sulfur content in the heavy oil before and after the treatment is as follows. Heavy oil (about 2 mg) is precisely weighed in a sample container, introduced into a reaction tube at 900 ° C. to 1000 ° C. with He carrier gas, and the sulfur component in the pyrolyzed heavy oil is oxygenated. Combusted and oxidized with gas and collected in the absorption liquid (SO ₂ , SO ₃ → SO ₄ ²⁻ ), and a fixed amount of the absorption liquid was injected into ion chromatography for quantification, and a calibration curve obtained from a known standard sample was obtained. Based on the calculation.
As is apparent from FIG. 1, when a 20N aqueous sodium hydroxide solution was used, a desulfurization rate of 15% could be achieved by treatment at 150 ° C. for 48 hours. Desulfurization could be carried out even when a 1N aqueous sodium hydroxide solution and a 10N aqueous sodium hydroxide solution were used, respectively, but the degree was extremely low. From the above results, even under conditions that are much milder than the supercritical water condition of 150 ° C., by stirring and mixing a saturated sodium hydroxide aqueous solution and heavy oil, it reacts with water in the presence of alkali. It was found that the sulfur component contained in heavy oil can be effectively removed without adding a metal or metal catalyst that generates hydrogen into the reaction system.

Example 2: Investigation using sodium hydroxide as electrolyte (part 2)
The treatment was performed under the same conditions as in Example 1 except that the treatment temperature was 100 ° C. and a 20N aqueous sodium hydroxide solution (supersaturated solution at 100 ° C.) was used. The results are shown in FIG. As is clear from FIG. 2, it was found that the desulfurization rate was improved at 100 ° C. lower than that of Example 1 by changing the aqueous sodium hydroxide solution to a supersaturated concentration solution at the treatment temperature.

Example 3: Examination of influence of electrolyte difference on desulfurization effect Except for using a 25N sodium hydroxide aqueous solution and a 6N magnesium chloride aqueous solution at a treatment temperature of 150 ° C (both are supersaturated solutions at 150 ° C). The treatment was performed under the same conditions as in Example 1. The results are shown in FIG. As is clear from FIG. 3, it was found that desulfurization can be performed in a shorter time than in Example 1 by changing the aqueous sodium hydroxide solution to a supersaturated concentration solution at the treatment temperature. In addition, since the same result was obtained even when using a supersaturated magnesium chloride aqueous solution, this desulfurization reaction is not limited to the case where an alkaline electrolyte is used, and even when a neutral electrolyte is used. It turned out to be a reaction that takes place. From the above results, the electrolyte solution of saturated to supersaturated concentration provides a reaction field for the removal of the sulfur component contained in heavy oil by the electric field due to abundant ionic charges, and in particular at the supersaturated concentration, the precipitated ionic crystals result. It is presumed that the sulfur component contained in heavy oil is effectively removed even when the interface electric field forms a reaction field suitable for desulfurization, even under milder conditions than supercritical water conditions. It was.

Example 4: Examination of desulfurization effect at normal temperature and pressure using a monovalent neutral electrolyte as an electrolyte Using sodium chloride and cesium chloride, four types of conditions shown in FIG. 4 (treatment temperature: 25 ° C., both of which are electrolyte solutions Is a supersaturated concentration solution at 25 ° C., where Oil is A heavy oil, W is an electrolyte solution, and the ratio is a volume ratio). As can be seen from FIG. 4, a desulfurization rate of 30% or more could be achieved in only 30 minutes after starting the treatment at 25 ° C. (treatment time of cesium chloride was 30 minutes).

Example 5: Examination of desulfurization effect at normal temperature and normal pressure using a divalent neutral electrolyte as an electrolyte Using magnesium chloride and calcium chloride, four conditions shown in FIG. 5 (treatment temperature: 25 ° C., both of which are electrolyte solutions Is a supersaturated concentration solution at 25 ° C., where Oil is A heavy oil, W is an electrolyte solution, and the ratio is a volume ratio). As can be seen from FIG. 5, a desulfurization rate of 35% or more could be achieved in only 30 minutes after starting the treatment at 25 ° C. (calcium chloride treatment time was 30 minutes). Since the desulfurization rate of Example 5 was generally superior to the desulfurization rate of Example 4, it was found that the valence of the electrolyte was more suitable than the monovalence.

Example 6: Investigation using magnesium chloride as an electrolyte (part 1)
When a treatment was performed under the same conditions as in Example 1 except that a supersaturated magnesium chloride aqueous solution was used and the treatment was carried out under the conditions shown in FIG. 6, the treatment was started at 20 ° C. as apparent from FIG. In just 30 minutes, a desulfurization rate of 30% or more was achieved.

Example 7: Investigation using magnesium chloride as an electrolyte (part 2)
When the supersaturated magnesium chloride aqueous solution was used and the treatment was carried out under the same conditions as in Example 1 except that the treatment was carried out under the conditions shown in FIG. 7, the treatment was started at 20 ° C. as apparent from FIG. In just 30 minutes, a desulfurization rate of 30% or more was achieved.

Example 8: Examination of the influence of the presence or absence of stirring on the desulfurization effect When the treatment was performed under the same conditions as in Examples 4 and 5, except that the stirrer was rotated and left for 24 hours without stirring and mixing, In any case, a desulfurization rate of 30% to 35% could be achieved. From the above results, it was found that stirring is not essential for desulfurization but is effective in shortening the treatment time.

  The present invention has industrial applicability in that it can provide a method for reforming heavy oil by simply removing sulfur components contained in heavy oil under mild conditions.

Claims (3)

  A method for reforming heavy oil, characterized in that a sulfur component contained in heavy oil is removed by mixing a saturated or supersaturated electrolyte solution with heavy oil.   The method for reforming heavy oil according to claim 1, wherein the reforming is performed under normal pressure to normal temperature to 200 ° C. under stirring. The method for reforming heavy oil according to claim 1 or 2, wherein a mixing ratio of the electrolyte solution having a saturated or supersaturated concentration and heavy oil is 20: 1 to 1:20 (volume ratio).