JPS5968391A - Coal liquefaction - Google Patents

Abstract

PURPOSE:To prepare a liquefied oil rich in light oil with a small amt. of hydrogen consumption by reacting a slurry consisting of crushed coal, a catalyst and a solvent in the presence of hydrogen at two specified temperatures. CONSTITUTION:In liquefying coal at a high temp. under a high pressure, a slurry is formed by mixing crushed coal, a catalyst and a solvent. After kept at 380- 430 deg.C for at least 20sec, the slurry is reacted at 440-550 deg.C. The coal to be used is pref. bituminous coal, semi-bituminous coal or brown coal which has been pref. ground to a particle size <80mesh. It is pref. to use liquefied coal oil as the solvent and to recycle it for use. Pref. catalysts include a compd. of a Group VIIIor VI element of the Periodic Table, such as a compd. of Fe, Co, Ni, Mo or W.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for liquefying coal, and more particularly to a method for producing liquefied oil rich in light oil with low hydrogen consumption.

In recent years, with the depletion of petroleum resources and the soaring price of petroleum, the need for alternative energy has been recognized5, and many studies have been conducted on the liquefaction reaction of coal as one of these alternative energies. There is.

By the way, in order to liquefy solid coal, it is necessary to increase the hydrogen atom/carbon atomic ratio, and therefore the addition of hydrogen is essential, and many processes have been proposed that change the method of adding hydrogen. .

However, in this coal liquefaction, high quality fuel I
In order to obtain I/IIJ, gasoline, or light oil that is used as a chemical raw material, the gasification reaction that occurs at the same time inevitably lowers the selectivity for hydrogen liquefaction, making the economics of hydrogen a problem. (・ru. Another problem in coal liquefaction is the presence of asphaltenes contained in the liquid product. In other words, if the amount of asphaltenes is large, the overall viscosity becomes high and the process In the distillation process, the transfer of light fractions to the phototom side increases, and furthermore, the separation in the solid-liquid separation process, which is essential for coal liquefaction, does not become sharp. .

In order to solve these problems, various improvement methods have been proposed, but none of them have been satisfactory.

In order to solve the problems of the conventional technology in coal liquefaction all at once, the present inventors aimed to reduce the amount of asphaltenes to make it lighter, and at the same time suppress gasification and improve selectivity for hydrogen liquefaction. Are you working hard to improve? i7
As a result of repeated research, he discovered that he could easily achieve his goal by dividing the reaction into two stages, and based on this knowledge he completed his invention.

That is, in liquefying coal under high temperature and high pressure, the present invention mixes pulverized coal, a catalyst, and a solvent to form a slurry, and liquefies the slurry in the presence of hydrogen at
After maintaining the temperature VC of 430℃ for more than 20 minutes,
The present invention provides a method for liquefying coal, which is characterized by reacting and stirring at a temperature of ~550°C.

The raw materials used in the method of the present invention include, for example, pulverized coal such as anthracite, bituminous coal, sub-bituminous coal, lignite, lignite, and mixtures thereof, and particularly preferred are bituminous coal, sub-bituminous coal, and lignite, with a particle size of 80 mesh or less. It is preferable to use one that has been crushed.

In addition, in the uninvented method, it is preferable to use liquefied coal oil as a solvent and recycle it, but other solvents may include, for example, coal tar fractions such as creosote oil and anthracene oil, heavy oil, light oil, Petroleum fractions such as kerosene, naphtha, and heavy oil, aromatic hydrocarbons such as naphthalene and tetralin, mixed oils thereof, and oils that have been hydrogenated in advance can also be used. The mixing ratio of these solvents and coal is O-5:1 to 4:1 by weight.
It is desirable to use a range of 1, more preferably l:l (・
It is in the range of 3:1.

Furthermore, the catalyst used in the investigation method is
? Highly active catalyst used for oxidation of coal
Although it may be different, preferred catalysts include compounds of group Xm of the periodic table and compounds of group Ⅰ of the periodic table, such as iron, cobalt, nickel, molybdenum, and tanksten. These compounds may be used alone or in combination of two or more.

Further, it can also be used by being supported on a carrier such as alumina or silica.

In addition, red mud, iron ore, and nickel ore, which have traditionally been used in coal liquefaction reactions, will also be used.

It is desirable that these catalysts be made into fine particles in order to form a slurry, and although the particle size varies depending on the type of reactor, it is generally preferable that the particle size is 100 meso or less. In addition, the amount of catalyst used depends on the type of coal, solvent, and catalyst used in the liquefaction reaction, or the particle size of the coal and catalyst. When a relatively large amount of catalyst with a cracking capacity or higher was used, a remarkable effect was observed on the reduction of asphaltenes.

Ru. In addition, in the case of non-invention, it is possible to increase the amount of catalyst, especially in iron-based catalysts, which have traditionally been considered to have relatively low activity, and as a result, a sufficient effect is exhibited, resulting in substantial selectivity. Light oil can be obtained.

In the present invention, in addition to the catalyst, an activation aid may be used if necessary.

In the method of the present invention, the pulverized coal, a solvent, and a catalyst are mixed to form a slurry, and the slurry is mixed with hydrogen during a preheating step and a reaction process to perform a liquefaction reaction. Regarding the mixing of this slurry with hydrogen, the position of hydrogen can be arbitrarily selected depending on the type of reactor, etc., and partial hydrogen is also possible. Furthermore, the hydrogen used in the method of the present invention (C) does not have to be pure hydrogen, and may contain a mixture of liquefied reaction gases such as light hydrocarbons, carbon oxides, and hydrogen sulfide. The optimum value varies depending on the reactor model, reaction pressure, etc.
It can be arbitrarily selected depending on the liquefaction reaction conditions.

In the uninvented method, first, the first reaction step - C1, the above-mentioned slurry is maintained in the presence of hydrogen at a temperature of 380 to 430 °C (020 minutes or more, preferably 20 to 120 minutes). At this time, the reaction When the temperature is low (・sometimes the reaction time is long, and when the reaction temperature is high, it is better to take a relatively short reaction time. Although it varies depending on the activity of the catalyst, generally it takes 40 to 120 minutes at a temperature of 380°C, and 20 minutes at a temperature of 430°C.
It takes about 40 minutes (1°C) Next, in the second reaction step, the slurry that has gone through the first reaction step is heated to a temperature of 440 to 550°C.
Preferably it is maintained for 5 to 60 minutes. In this reaction step, as in the first stage reaction, it is preferable that the reaction time is long when the reaction temperature is low, and that the reaction time is relatively short when the reaction temperature is high. As with the first stage reaction, the relationship between reaction humidity and reaction time varies depending on the type and amount of coal and solvent used, the activity of the catalyst, etc.
Generally, it is recommended that the time be 40-120 minutes at a temperature of 440°C, and 5-30 minutes at a temperature of 550°C.

In this second stage reaction, if the reaction temperature becomes less than 440'C or the reaction time is too short, the liquefaction rate will decrease and the amount of light oil will decrease, and the reaction temperature will decrease to 550'C.
If the reaction time is exceeded or the reaction time is too long, the coking reaction and the amount of gas generated will increase.

The reaction pressure in the uninvented method is 50 to 350 K97c
A range of nI is desirable, preferably 100 to 300 K
The range is q/crl.

The product oil thus obtained can be made into a product through distillation and solid-liquid separation steps. This distillation and solidification
The operation of the liquid separation process is 1. In the uninvented method, the liquid viscosity is low, which makes it extremely easy. In addition, the acquisition rate of light oil is generally high in non-invention (・).

In the uninvented method, in the first reaction step, the coal slurry containing the catalyst is allowed to remain in the presence of hydrogen for a relatively long time at a relatively low crystallinity, and in the second reaction step, The feature is that the reaction is carried out at high temperature, and by such an extremely simple operation, the conversion rate of coal and the acquisition rate of light oil are increased, asphaltene content is reduced, gas generation is suppressed, and hydrogen production is increased. Increased selectivity for liquefaction.

Next, the invention will be explained in more detail with reference to Examples.

Example: The charcoal in the hood was pulverized to an ioo mesh size or less, and dried in a vacuum dryer (1
50% dried at 10°C until the moisture content is less than 5%
g (ashless anhydrous basis), decrystallized anthracene oil 100.5
', and fine particles of catalyst) 10.7. ! i', (
1-54! into an autoclave, and then this
Hydrogen gas into the toclave reactor at 140 K9/cn
After filling the mixture, it was heated to cause a reaction.

The reaction conditions were a one-stage reaction at Nα1 of 460°C for 60 minutes;
N[l 2 at 400'C, 60 minutes and 460''C, 6
2-stage reaction for 0 minutes, 14 reactions for N[13 at 460° C. for 120 minutes. After the reaction is completed, the reactor is quickly cooled down using a high-speed fan, and the gas and oil components are analyzed.
The results shown in Table 1 were obtained. Nα2 is an uninvented example, and as is clear from Table 1, a reduction in asphaltenic substances and suppression of organic gas by-production were observed.

Example 2 Using Australian lignite, the difference between the first-stage reaction and the second-stage reaction was examined in the same manner as in Example 1, but with different reaction times. The results are shown in FIG. 1. In this case, the reaction temperature for the first stage reaction was 460°C, and for the second stage reaction, it was first heated to 430°C for 30°C.
After that, the temperature was raised to 460°C to conduct the reaction, and the relationship between the reaction time, yield, and hydrogen consumption was examined. In Figure 1, A is the uninvented method, and B is the conventional method. 1, 1 and 2 are the hydrogen consumptions of the method, respectively, and 1' are the yields of light oil, asphaltene, and organic gas by the method of the present invention.

``■'' and ``■'' indicate the yields of light oil, asphaltene, and organic gas, respectively, in the conventional method.

As is clear from this figure, the method of the present invention shows very superior results compared to the conventional one-stage reaction.

Example 3 Horonai coal pulverized to 400 mesh or less, decrystallized anthracene oil, ferrous hydroxide, and sulfur were stirred and mixed to prepare a raw material slurry. The preparation conditions were such that the mixing ratio of coal and de-crystallized anthracene oil was 3 nia in terms of heavy duty ratio, ferrous hydroxide was 3 nya in the form of Fe, and sulfur was equimolar to iron.

Figure 2 shows an example of this small flow-type continuous testing device (
Coal processing capacity 20Kg/day), as mentioned above (・
The strained raw material slurry is introduced into the raw material tank through the supply pipe 1, and then sent to the first stage reaction tower 1 (.C).Meanwhile, hydrogen residue is simultaneously supplied from the supply pipe 3 The raw material slurry is sent to the first stage reaction tower 4.
After being maintained at oc for 50 minutes, the second stage reaction column 5 (・C
The reaction was carried out for 50 minutes at a temperature of 460'C and a pressure of 200Kg/cJ. This reaction mixture is then sent to a gas-liquid separator 6, the gunk is discharged from a gas discharge pipe 7, and the slurry is stored in a product slurry tank 8.

The results thus obtained are shown in Table 2.

Table 2

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between reaction time, yield, and hydrogen consumption in the uninvented method and the conventional method, and FIG. 2 is a flowchart of a small-sized flow-type continuous paper trial apparatus. In FIG. 2, reference numeral 2 is a raw material tank, 4 is a first stage reaction tower, 5 is a second stage reaction tower, 6 is a gas-liquid separator, and 8 is a product slurry tank. Patent applicant Asahi Kasei Kogyo Co., Ltd. Agent A form Akira 1st figure 2

Claims (1)

[Claims] 1. To liquefy coal under high temperature and high pressure, pulverized coal, catalyst, and solvent are mixed to form a slurry, and the slurry is maintained at a temperature of 380 to 430 ° C for 20 minutes or more in the presence of hydrogen. A method for liquefying coal, which is then reacted at a temperature of 440 to 550°C.