JPH06102785B2 - Coal liquefaction method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a coal liquefaction method for producing a liquid fuel from coal.

[Prior Art] The history of the development of a coal liquefaction method is a process of searching for low-temperature and low-pressure reaction conditions using a catalyst and a solvent for relaxing the reaction conditions from liquefaction under high-temperature and high-pressure reaction conditions. The NEDOL method, which is currently a typical coal liquefaction method, uses 450 ° C and 20 MPa.
It is liquefied using an iron catalyst under the temperature and pressure of.

The two-stage liquefaction method, which is being researched and developed in the United States, is a process aiming at a high oil yield by combining molybdenum-based highly active catalysts under more mild reaction conditions.
However, with the current coal liquefaction technology, there is no technology that has reached the point where it can economically compete with petroleum, and it must be said that the road to achieving that purpose is far away. In other words, the biggest challenge in putting coal liquefaction technology to practical use is improving its economic efficiency. As means for improving economic efficiency, in the direction of reducing manufacturing costs, reaction conditions are moderated by new catalysts to reduce fixed costs, catalyst consumption and utility usage to reduce operating costs, etc. There is an improvement in hydrogen use efficiency.

In addition, in order to increase the profit of the whole process, the quality and yield of the produced oil are improved and the processing speed is increased by optimizing the catalyst and reaction conditions, and research is needed to solve these problems.

[Problems to be Solved by the Invention] At present, in the primary liquefaction process of coal, except for the two-stage liquefaction method in the United States, a method of using a powdered iron sulfide catalyst obtained by sulfurizing synthetic iron sulfide or ground iron oxide is the mainstream. Regarding the function of the iron-based catalyst, the smaller the particle size is, the better the activity and the dispersibility in the reactor. Regarding the amount of catalyst used, 3% by weight is added to coal. Assuming an oil production capacity of 100,000 barrels / day as the scale of a practical plant, the amount of treated coal will be about 30,000 tons per day, and the amount of catalyst required for it will reach 900 tons per day. Attempting to obtain this amount of highly active catalyst by the grinding method requires a considerable amount of energy. In addition, there is a problem in economics regarding the synthetic method.

The present invention was obtained as a result of research based on a novel viewpoint, without being caught by the existing concept of the function expression of the catalyst, does not require the above-mentioned pulverization and synthesis, and has a catalytic activity equal to or higher than that of the powder catalyst. While dynamically expressing and maintaining
And it aims at providing the method of liquefying coal.

[Means for Solving Problems] The coal liquefaction method of the present invention that achieves the above-mentioned object is an average particle size of 0.5 to 20 m of iron-based particles such as metallic iron particles and iron alloy particles.
In a packed bed formed by packing m, the packing is vibrated so that these iron-based particles collide, and the packed bed is liquefied under the conditions of 350 to 450 ° C. and an initial hydrogen pressure of 10 to 20 MPa. It is characterized by supplying hydrogen, sulfur, a solvent and coal to liquefy the coal while producing an iron sulfide catalyst on the spot.

In the vibration field, the fillings collide with each other or the fillings collide with the wall surface violently. As a result of this collision, changes in lattice defects, lattice irregularity / amorphous structure, specific surface area, and surface energy occur, and the activity of solid is improved. These changes on the solid side are called mechanochemical effects. The present invention utilizes this effect as a mechanochemical catalyst. As the mechanochemical catalyst effect, not only the above-mentioned activity improving effect but also the effect of preventing the activity deterioration due to the constant renewal of a new fracture surface or the regeneration effect is expected as a secondary effect.

The iron-based particle shape forming the catalyst packed bed in the present invention is
It may be a sphere, a rod, or an irregular shape. As the catalytically active metal, iron, molybdenum, cobalt, nickel, a mixture thereof or the like is used. Further, catalyst particles in which the surfaces of the inert particles are coated with an active metal are also used. The packed bed can also be formed by mixing ceramic spheres, glass spheres, and catalyst particles.

Regarding the average particle size of iron-based particles, in order to increase the collision force,
If it is too small, it is unsuitable, and if it is too large, the number of collisions per unit volume decreases, so 0.5
It is in the range of -20 mm, preferably in the range of 1-5 mm.

As a method of vibrating the filling, it is possible to vibrate the entire container, or use the electromagnetic induction to vibrate only the filling. The vibration frequency is 10 Hz or higher, preferably 20 Hz or higher because the number of collisions is also a function of the vibration frequency, and the more collisions the more the mechanochemical catalytic effect is exhibited.

For heating the packed bed, existing technology such as external heat or internal heat is applied, and the method for supplying hydrogen, sulfur, solvent, and coal is a usual method.

It is also possible to improve the reaction results by optimizing the reaction conditions of each compartment as a multi-stage reactor in which each compartment is filled with different catalyst particles as the packing container, and each compartment is filled with different catalyst particles.

As an application of the present invention, for example, another liquefaction process 1 such as a NEDOL-method primary liquefaction reaction step, a two-stage liquefaction first-stage liquefaction step, etc.
The sub-liquefaction process can be replaced by the present invention.

EXAMPLES Next, the present invention will be described in more detail with reference to examples.

Example 1 A micro autoclave having an inner diameter of 14φ × 180 L was used, on one side of which 3 mmφ iron balls were about 94 g, and on the reference side autoclave, the average particle size was 3 μm, which corresponds to metallic iron 3 wt% with respect to coal.
The liquefaction experiment of Pacific coal was conducted under the reaction conditions shown in Table 1 after filling with the iron oxide catalyst of No. 1. Vibration frequency of autoclave is 1600rp
m, amplitude is 4 mm. The coal / solvent ratio was set to 1.5 / 7, which is much smaller than the usual 3/4 for convenience of product handling. Further, S, which is a co-catalyst, was added in a stoichiometric ratio required for sulfurization of the iron catalyst. Soxhlet reacts with TH
The F-soluble matter, benzene-soluble matter, and hexane-soluble matter were extracted. FIG. 1 shows the transition of the conversion rate to the soluble component in each solvent when the reaction time was changed.

Example 2 Using an autoclave having an inner diameter of 14 mmφ × 325 mmL, 1.2 mmφ
1.5g of iron balls are filled, coal 3g, solvent 7g, hydrogen initial pressure 10MP
The relationship between the amount of catalyst and the reaction rate of coal was investigated at a temperature of 450 ℃. The vibration method was a method in which the center of the autoclave was used as a fulcrum and the bottom of the head vibrated at an angle of 45 ° from the horizontal, and the number of vibrations was 45 rpm for 60 minutes. Powdered iron oxide was used as a reference catalyst. At that time, sulfur was added as a cocatalyst in a stoichiometric ratio required for sulfurization. An experiment was performed in which sulfur was added up to 1.7 g in the iron ball side autoclave filled with 1.5 g of iron balls. For the reaction product, a benzene-soluble content and a hexane-soluble content were obtained by the Soxhlet extraction method, and the reaction rates were calculated.

Fig. 2 shows 1.2m when using powdered iron oxide and sulfur (○)
The results of coal liquefaction when using iron balls of m and sulfur (●) are shown. The horizontal axis of ○ is the addition amount of iron oxide, and the horizontal axis of ● is the reduction amount of iron balls (the amount of catalyst produced as fine particles from iron balls).

From the results shown in FIG. 2, it can be seen that there is no difference in the catalytic effect between the present invention (when using iron balls) and the conventional technique (when using powdered iron oxide). It is considered that this is because iron sulfide was generated on the surface of the iron ball due to the action of hydrogen sulfide generated from the added sulfur, and fine iron sulfide was separated from the surface and acted as a liquefaction catalyst.

[Effects of the Invention] As described above, according to the present invention, the following effects can be obtained.

1) When the reaction time became longer, the mechanochemical catalyst effect was observed to improve the liquefaction reaction result, and the result surpassed that of the powder catalyst.

2) Even if a powder catalyst is not used, the catalytic activity can be expected to be expressed in the active metal packed bed vibration field.

3) The activity can be controlled by changing the number of vibrations and the amplitude.

[Brief description of drawings]

FIG. 1 shows the results of coal liquefaction results obtained by carrying out the present invention. ● indicates the liquefaction result according to the present invention, and ■ indicates the liquefaction result using the existing powdered iron catalyst. FIG. 2 is a result of a coal liquefaction experiment obtained by carrying out the present invention. In FIG. 2, ● indicates the liquefaction result according to the present invention, and ○ indicates the liquefaction result using the existing powdered iron catalyst.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Morio Yumura 1-1, Higashi, Tsukuba-shi, Ibaraki Industrial Technology Institute, Institute of Chemical Technology (72) Inventor Fumikazu Igasaki 1-1-chome, Tsukuba, Ibaraki Industrial Technology Institute of Chemical Technology In the laboratory (72) Inventor Takao Omori 1-1-1, Higashi, Tsukuba, Ibaraki Prefectural Institute of Chemical Technology (56) Reference US Patent 4123348 (US, A) US Patent 3867114 (US, A)

Claims (1)

[Claims] 1. In a packed bed formed of a packing composed of iron-based particles having an average particle size of 0.5 to 20 mm, the packing is vibrated so that the iron-based particles collide, and the packed bed is heated to 350 to 450 ° C.
A method for liquefying coal, which comprises liquefying coal while supplying hydrogen, sulfur, a solvent and coal under the liquefaction condition of an initial hydrogen pressure of -20 Mpa to generate an iron sulfide catalyst on the spot.