JP2001072983A - Method for improving yield of light component in hydrogasification reaction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize a heavy oil component formed as a by-product in the hydrogasification reaction of a hydrocarbon feed and to improve the yield of a light component by recovering the heavy oil component and then subjecting it together with a hydrocarbon feed to hydrogasification reaction. SOLUTION: A hydrocarbon feed (a) and hydrogen (b) are introduced into a hydrogasification apparatus 1 and subjected to hydrogasification reaction at a high temperature under a high pressure of 1 MP or higher, thus forming a product gas (c) and an ungasified raw material residue (d). The product gas (c) is cooled in a cooling apparatus 2 with a high-pressure vapor, and a heavy oil component (e) is recovered. A gas (f) is cooled with water in a cooling apparatus 3, and benzene (g) is recovered. A finally obtained gas (h) is caused to pass through purification steps, such as steps of CO-modification and desulfurization, and a hydrogen separation step and then is taken out as methane. The recovered heavy oil component (e) is charged again into the hydrogasification apparatus 1 to be subjected to hydrogasification reaction together with the hydrocarbon feed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a process for recovering heavy oil as a by-product from methane, benzene and heavy oil produced in a hydrogenation gasification reaction of hydrocarbons, and efficiently converting it into methane and benzene. More specifically, a method of recovering a heavy oil produced from a hydrogenation gasification reaction of a raw material hydrocarbon, recovering the recovered heavy oil component and subjecting the same to a hydrogenation gasification reaction, and subjecting the heavy oil component to a hydrogenation gasification reaction. To improve the yield of lighter methane and benzene.

[0002]

2. Description of the Related Art As shown in FIG. 1, the following methods are known as gasification methods for hydrocarbons (heavy oils such as pulverized coal, naphtha, orinoco tar, sludge, organic waste, etc.). ing.

[0003] For example, there is a method in which a hydrocarbon is gasified with oxygen and steam to produce a synthesis gas (CO + H ₂ ), which is methanated by a contact process (partial combustion-methanation process: see the lower part of FIG. 1). ). Although this gasification technology using oxygen and steam and the catalytic methanation process of syngas are already established methods, gasification must be performed at a temperature of 1500 ° C or higher, and in terms of thermal efficiency, an excellent method is considered. I can't say.

[0004] In the hydrogenation gasification method for hydrocarbons (see the upper part of FIG. 1), the raw material hydrocarbons are heated to a high temperature (700 to 120 ° C.).
0 ° C) and high pressure (1MPa or more) directly react with hydrogen to cause rapid pyrolysis of the raw materials and hydropyrolysis of the pyrolysis products to produce gas with methane as the main product. It has gained. The hydro-gasification process is different from the above method, the reaction temperature is low and the amount of produced CO ₂ is about 20
%, And has the advantage of high environmental compatibility.

In a method for hydrogenating and gasifying hydrocarbons,
Assuming that coal is used as a raw material,
Among fossil fuels, it is a particularly abundant reserve of energy, a widespread energy source worldwide, and relatively stable in price. Therefore, when producing methane by a hydrogenation gasification reaction using coal as a raw material, low-cost coal can be converted to alternative natural gas (city gas) having high commercial value. In other words, the hydrogasification of coal is extremely useful for energy policies that require stable supply and coping with price fluctuations.

Another advantage of the hydrogenation gasification reaction is that useful by-products such as benzene, toluene, and xylene (hereinafter represented by benzene, but also "BTX" as necessary) can be obtained. In particular, benzene is highly useful as a raw material for chemical products and has high added value.
Therefore, the hydrogenation gasification reaction of hydrocarbons is a very useful reaction that can produce both a city gas raw material and a chemical product raw material.

[0007] In the above-mentioned hydrogenation gasification of hydrocarbons, the selectivity of the distribution of the reaction product (methane, benzene) depends on the reaction temperature and the reaction time (reaction product residence time). Therefore, when the size of the reaction apparatus is fixed, the reaction time (reaction product residence time) is not variable, so that only the reaction temperature is a determinant of the distribution selectivity of the reaction product. In order to improve the methane yield in the product, for example, if the operation is performed at a pressure of 7 MPa, a reaction at 900 ° C. or higher is required. On the other hand, if the aim is to improve the benzene yield in the product, 800-900 at a pressure of 7 MPa
Reaction at about ° C is desirable.

However, in this hydrogenation gasification reaction, heavy oil components other than methane and benzene are generated.
In particular, as the reaction temperature decreases, the amount of heavy oil produced also increases. This heavy oil is mainly composed of polycyclic aromatics such as naphthalene, phenanthrene and pyrene, but not only is it difficult to separate and purify these polycyclic aromatics from benzene, but also its commercial value is Lower than.

[0009]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a technique for effectively utilizing heavy oil generated in a hydrogenation gasification reaction of hydrocarbons.

[0010]

Means for Solving the Problems The present inventors have conducted research on efficient lightening of heavy oil produced as a by-product in the hydrogenation gasification reaction of hydrocarbon feedstocks. It has been found that when the recovered heavy oil is subjected to a hydrogenation gasification reaction together with a hydrocarbon feedstock, the heavy oil is lightened and the yields of methane and benzene are improved. The present invention has been completed on the basis of such findings, and provides the following method. 1. In a hydrogenation gasification reaction using a hydrocarbon as a raw material, after recovering heavy oil generated as a by-product in a hydrogenation gasification reaction, the recovered heavy oil is supplied to a hydrogenation gasification reaction together with a raw material hydrocarbon. For improving the yield of light components in a chlorination reaction. 2. The method for improving the yield of a trait component according to claim 1, wherein at least one selected from pulverized coal, naphtha, heavy oil, sludge, and organic waste is used as the raw material hydrocarbon. 3. Item 3. The method for improving the yield of light components according to Item 2, wherein pulverized coal is used as the raw material hydrocarbon. 4. By controlling the temperature of the hydrogenation gasification reaction,
Item 4. The method for improving the yield of light components according to Item 1, wherein the degree of lightening of heavy oil is controlled.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to embodiments shown in the drawings.

FIG. 2 is a flow chart showing a conventional hydrogenation gasification reaction process using a hydrocarbon as a raw material.

When the raw material (a) and the hydrogen (b) are introduced into the hydrogenation gasifier 1, a generated gas (c) and a raw material residue (d) that are not gasified are generated. Hydrogen (b) is preheated to a high temperature, and the reaction pressure is a high pressure of 1 MPa or more. This generated gas
(c) is cooled by high-pressure steam in the cooler 2,
Heavy oil (e) is recovered. Next, the gas (f) is supplied to the cooler 3
At which time benzene (g) is recovered. The gas (h) finally obtained is further subjected to a known purification step (not shown) such as CO conversion and desulfurization and a hydrogen separation step.
(Not shown) and is extracted as methane.

FIG. 3 is a flow chart showing a process for hydrogasification of hydrocarbons according to the present invention. This process is substantially the same as the process shown in FIG. 2 except that the generated heavy oil is recovered and added to the hydrogenation gasifier again in the conventional process shown in FIG.

That is, in the method of the present invention, the hydrogenated gasification reaction of the raw material hydrocarbon is carried out in the same manner as in the above-mentioned conventional method, and the heavy oil (e) is recovered in the cooler 2 and then the recovered heavy The oil component (e) is charged into the hydrogenation gasifier 1 again,
A hydrogenation gasification reaction of heavy oil is performed together with the raw material hydrocarbons. Hereinafter, this method may be referred to as an oil recycling method. According to this oil recycling method, the generated heavy oil is always collected and returned to the hydrogenation gasifier 1. According to this process, the generated substances other than the raw material residue can be substantially only useful gas (h) and benzene (g).

In the present invention, gas (h) and benzene (f)
Can be controlled mainly by the reaction temperature and the reaction time (reaction product residence time). That is, in a reactor of a specific scale, the reaction time is constant, so that the ratio of the reaction product can be determined by changing the reaction temperature. For example, if the aim is to improve the methane yield in the product,
At 7 MPa, a reaction at 900 ° C or higher is required. On the other hand, when aiming to improve the yield of benzene in the product,
At a pressure of 7 MPa, a reaction at about 800 to 900 ° C. is desirable. Note that these conditions can be appropriately set as needed, and are not particularly limited.

In the present invention, not only coal but also a wide range of organic substances such as heavy oils such as naphtha and orinocotar; sludge; and organic wastes such as plastic waste and rubber waste can be used as hydrocarbons. it can. Since these are all easier to gasify than coal, the method of the present invention can be easily applied.

[0018]

According to the oil recycling method of the present invention,
The heavy oil, which is a by-product of low utility, can be efficiently reduced to methane and benzene with high utility.

[0019]

EXAMPLES Examples and comparative examples are shown below to further clarify the features of the present invention. Comparative Example 1 Table 1 below shows typical verification test conditions and results of the hydrogenation gasification reaction process shown in FIG. As raw material hydrocarbons, finely pulverized coal (200 mesh under 70%) was used. Example 1 Coal was hydrogenated and gasified by the oil recycling method according to the present invention shown in FIG. That is, the same reaction as in Comparative Example 1 was performed except that the recovered heavy oil component was supplied to the hydrogenation gasification reaction process together with the raw coal fines. The results are shown in Table 1.

[0020]

[Table 1]

The yield of the product is indicated by the carbon conversion (the amount of each substance produced based on the amount of carbon in the raw coal). The balance of the product is essentially the raw material residue.

From the results shown in Table 1, according to the method of the present invention in which the recovered heavy oil is again subjected to the hydrogenation gasification reaction,
The total amount of heavy oil is reduced, and the amount of monocyclic aromatics such as methane and benzene increases as compared with the conventional method shown in Comparative Example 1. Thus, it is clear that the method of the present invention increases the economics of the entire reaction process. Example 2 In the method of the present invention, the degree of lightening of heavy oil can be controlled by controlling the temperature during the hydrogenation gasification reaction. An example of the result when the reaction temperature is changed is shown below.

In the oil recycling method according to the present invention shown in FIG. 3, a verification test was conducted with the reaction conditions at a temperature of 950 ° C. and a reaction pressure of 7 MPa. Table 2 shows the results.

[0024]

[Table 2]

As is clear from the results shown in Table 2, by changing the reaction conditions, the lightening of heavy oil can be further promoted, and methane containing only a small amount of CO _x can be obtained in high yield. it can. Comparative Example 2 In the hydrogenation gasification reaction process shown in FIG. 2, a reaction was carried out using orinocotal as a raw material hydrocarbon. Example 3 In the oil recycling method according to the present invention shown in FIG. 3, a demonstration test was performed using orinoco tar as a raw material hydrocarbon. Table 3 shows the reaction conditions and the composition of the product. Table 3 also shows the results of Comparative Example 2.

[0026]

[Table 3]

From the results shown in Table 3, it is clear that the oil recycling method according to the present invention exerts an excellent effect even when a raw material hydrocarbon other than coal is used.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an outline of a typical methane production process using coal as a raw material.

FIG. 2 is a flowchart showing a hydrogenation gasification reaction of coal according to a conventional method.

FIG. 3 is a flowchart showing a hydrogenation gasification reaction of coal according to the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Takayuki Higashi Inventor Osaka Gas Co., Ltd. 4-1-2 Hirano-cho, Chuo-ku, Osaka-shi, Osaka (72) Inventor Masanori Kawamoto Hirano-cho, Chuo-ku, Osaka-shi, Osaka Chome 1-2, Osaka Gas Co., Ltd.

Claims (4)

[Claims] In a hydrogenation gasification reaction using a hydrocarbon as a raw material, after recovering heavy oil generated as a by-product, the recovered heavy oil is subjected to a hydrogenation gasification reaction together with the raw material hydrocarbon. A method for improving the yield of light components in a hydrogenation gasification reaction. 2. The method for improving the yield of a trait component according to claim 1, wherein at least one selected from pulverized coal, naphtha, heavy oil, sludge, and organic waste is used as a raw material hydrocarbon. 3. The method for improving the yield of light components according to claim 2, wherein pulverized coal is used as the raw material hydrocarbon. 4. The progress of lightening of heavy oil is controlled by controlling the temperature of the hydrogenation gasification reaction.
3. The method for improving the yield of light components according to 1.).