JPS59147082A - Coal liquefaction - Google Patents

Abstract

PURPOSE:Coal liquefaction is effected using coal, a hydrogen-containing gas, an iron catalyst and a specially composed solvent to obtain good quality oil in high efficiency. CONSTITUTION:In the coal liquefaction using coal, a solvent, a hydrogen-containing gas and an iron catalyst under less than 200kg/cm<2> hydrogen pressure, the proportion of the fraction boiling over 350 deg.C is kept lower than 35%, preferably 25% in the solvent. The proportion of fractions are preferably maintained by distilling off a part of the fraction boiling over 350 deg.C as a product out of the system.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the control of a solvent for efficient coal liquefaction in a relatively low-pressure coal liquefaction method using a solvent, hydrogen-containing gas, and iron-based catalyst. It is something.

Conventional technology The principle of coal liquefaction is to add hydrogen to coal to convert it into light and heavy oil components with higher hydrogen content, but the reaction of adding hydrogen to coal is extremely slow. This is usually carried out at a high temperature of 400 to 500° C. and under a hydrogen pressure of 100 to 300 kg/cnt or more.

At this time, various catalysts are used to increase reaction efficiency. As a catalyst, an inexpensive iron-based catalyst is often used, except for the H-coal method in the United States.

This is because in a coal liquefaction reaction system, the lifetime of the catalyst is short due to coking, etc., so it is often used disposable, and it is desirable to use a catalyst that is as inexpensive as possible.

The Bergius-type method using an iron-based catalyst is a method in which an iron-based catalyst, a core agent, and coal are mixed and liquefied under high-pressure hydrogen. As an iron-based catalyst, Fe2 generated from an aluminum field
O3, red mud mainly composed of A6203, iron ore-1-sulfur, dust generated from converters and gasifiers (JP-A-56
-1.05504. Patent Application No. 56799+17) etc. are used. As a solvent, the boiling point of the liquefied reaction product is 2C.
Using a wide range of distillates from 0 to 568°C, the boiling point is 735°C.
All distillates above 0°C are circulated as a solvent.
As a product, 9 relatively light fractions with a boiling point of 35[]0C or less are taken out.

The problem with this Hergius type is that while coal is liquefied, heavy oil with a boiling point of 350°C or higher is lightened to a boiling point of 350°C or higher, so the pressure is relatively high, and at least 20°C is required.
It is necessary to operate the liquefaction equipment under conditions of 0 kg/C11 t or more, and the reaction conditions are severe, which makes it difficult, and the material of the reactor also increases the Ni and Cr content, making it expensive. , there is a risk that hydrogen will be wasted and economic efficiency will be lost.

Therefore, the mainstream of recent liquefaction processes is
This is a method in which liquefaction is carried out using the hydrogen donating property of the solvent under reaction conditions of a reaction pressure of 140 to 200 kg/cm. This includes the United States' E]) S Law, 5RCI, and 5RCII Law. However, in these methods, hydrogen consumption is low and the liquid yield in the first stage is low, probably because they rely on weak catalytic effects such as ash, so like the Bergius method, iron-based catalysts are used, Relatively calm 140-2001tg/cr
There is also an attempt to liquefy at a pressure of d.

140-200kg using iron-based catalyst like this
The problem with the liquefaction method under pressure in /cylt is that if you extract only the fraction below 350°C with the aim of obtaining a high-quality product, as in the case of Lugius-type liquefaction, the boiling point is above 650°C. Since it is not possible to sufficiently lower the heavy fraction to a boiling point of 650° C. or lower, the heavy fraction with a boiling point of 650° C. or higher actually accumulates, which impedes the liquefaction reaction of coal.

Purpose of the Invention The present invention uses such an iron-based catalyst, and the reaction hydrogen pressure is 1
This method improves the problems of coal liquefaction under relatively mild conditions of 40 to 200 kg/m, and innovates heavy oil whose main component is a fraction with a boiling point of 350°G or less at a high yield. The present invention provides a method.

As a result of various tests and research on the accumulation of heavy fractions with a boiling point of 350°C or higher and the liquefaction reaction of coal, Komei Narimoto and others at 4P in November found that the proportion of distillates with a boiling point of 50°C or higher in the solvent was 25%. It was discovered that when the amount exceeds 35%, the liquid yield decreases, and when it exceeds 35%, there is a further decrease, and the present invention was developed based on this discovery.

The present invention uses coal, a solvent, a hydrogen-containing gas, and an iron-based catalyst in a coal liquefaction method carried out at a reaction hydrogen pressure of 200 kg/C1d or less, in which the proportion of fractions with a boiling point of 650°C or higher in the solvent is reduced to 35% or less. A particularly preferred method is to control the liquefaction rate to 25% or less to prevent a decrease in the liquefaction rate.

Although there are no particular limitations on the type of coal used in the present invention,
Lignite that is easily liquefied under relatively mild reaction conditions, 111i-f
ffi? Blue coal is suitable. The reaction pressure is 140~2
001=, q/if is about 420 as the reaction temperature
~470°C is good. In addition, there is no particular limitation as a liquefaction catalyst, and conventionally used iron hydroxide, iron oxide, iron sulfide,
Any of red mud, iron ore, pyrite, converter dust, gasifier dust (% patent application No. 56-9917), etc. may be used. As for the amount of catalyst added, the paste liquefaction reaction proceeds with high efficiency, but there is an upper limit to its effectiveness, and adding too much will increase the amount of inorganic substances and substances in the liquefaction residue, leading to troubles in the solid-liquid separation or distillation process. Therefore, it is desirable to have Fe atoms of 05 to 000 per coal.

The means for controlling the proportion of fractions with a boiling point of 350°C or higher in the solvent fraction to 65% or less, preferably 25% or less, is not particularly limited, but a suitable means is to control the fraction with a boiling point of 350°C or higher by distillation. ℃ or higher as a product in small quantities to suppress the accumulation of fractions with boiling points of 650℃ or higher, or alternatively, distill the liquefied product and take out the fraction with a boiling point of 200 to 538℃, and then add hydrogen. The objective is to reduce the amount of distillate at a temperature of 350°C or higher by making it lighter. In addition, after extracting only the fraction above 350℃ and hydrogenating it to make it lighter,
It may be mixed with the 0°C fraction.

For total hydrogenation of fractions, for example, Mo, Ni, Co
.

A403 A403
, S i02゜・I・+02 , 13203 ,
It is used by being coated on a carrier made of oxides such as p, , o, , and MgO. The most common one is Mo-Ni.

Metals from combinations such as Mo-Co and W-Ni are d2
Possible examples include Fe-supported materials, Fe-loaded ores, and dust. The reaction conditions were 350-450°C, hydrogen pressure 5
0~150)cg/C1r! So, the boiling point is 20 [ ] ~ 5
The entire fraction at 38°C may be hydrogenated, or, for example, the fraction with a boiling point of 350 to 538°C may be taken out and partially hydrogenated.

Alternatively, using high pressure steam, 400
The fraction having a temperature of 350''°C or higher may be subjected to one-layer reforming at a temperature of about 600°C.

FIG. 1 shows a schematic flow route for implementing the present invention.

[Example 1] A coal liquefaction experiment was conducted under the following conditions using a coal liquefaction plant with a coal throughput of 1 kg/hr and a 20e scale distillation apparatus.

(2) Coal used The sub-bituminous coal shown in Table 1 was pulverized to a size of 1()D mesh or less, dried under vacuum, and used.

Table 1 ■ Reaction time 1 hour ■ Reaction temperature 450℃ ■ Pressure Reaction hydrogen pressure 190 kg/cr/1 ■ Solvent Boiling point 200-568℃ fraction of coal liquefaction product ■ Solvent ratio Solvent/coal weight ratio 1.5 ■ Catalyst 4
Red mud of wt (anhydrous carbon equivalent) and 1wt% (anhydrous carbon equivalent)
However, there are two methods for extracting the product: method A and method B.
I went by method.

Method A Only the fraction with a boiling point of 650°C or lower is extracted from the system as a product.

Method 11: The fraction with a boiling point of 350°C or higher is extracted from the system in small quantities as a product, so that the fraction with a boiling point of 350°C or higher in the solvent is 25% or less.

Two methods, A and B, were operated continuously for 100 hours each. The results are shown in Figures 2 (a) and (b).

The liquid yield was evaluated by distilling the liquefied product and obtaining a boiling point of 20
It was determined by subtracting the amount of solvent before reaction from the total amount of distillate oil at 0 to 568°C.

As is clear from Figure 2, in method A, the boiling point of the solvent is 3
As the proportion of the two fractions above 50° O increases with time, the liquid yield decreases. On the other hand, in method B, the boiling point is 350°
By extracting fractions of C or higher little by little, the boiling point is 35.
Control the proportion of the fraction above 0°C to about 20 to 25%, and
A stable saliva yield of 7 to 48 (calculated as anhydrous charcoal) was obtained. Table 2 shows the composition of the product oil obtained by Method 13.

Figure 5 shows the relationship between the proportion of fractions with a boiling point of 350°C or higher in the solvent and the liquid yield in Method A. As shown in Figure 6, in order to obtain a liquid yield of 47 cm or more, the boiling point of the solvent must be 3
The fraction at 50° C. or higher should be controlled to 25% or less, and to obtain a liquid yield of 40% or more, the fraction should be controlled to 55% or less.

[Example 2] Coal liquefaction plant with coal processing capacity of 1 to 9/hr scale, 2D
I! Coal liquefaction experiments were conducted under the following conditions using a scale distillation unit and a 21/hr scale continuous hydrogenation unit.

■ Coal used: Same coal as in Example 1 ■ Reaction time: 1 hour ■ Reaction temperature: 450°C (4) Pressure: Reaction hydrogen pressure: 1701 cg/o
rt”ri m 1vIll ratio Solvent/coal ii ratio 1.5 Catalyst Coal iron bath gasifier
164186) and 1.2 w+% of elemental sulfur (in terms of anhydrous coal).
Although a fraction of °C was used, the method for preparing the solvent was
Two methods were used: method and method D.

Method C: Of the liquefied product, a portion of the fraction with a boiling point of 650°C or less is extracted as a product, and the remainder is used as a solvent. Therefore, all products are 58 points below 650°C.

■) Method Among the liquefied products, a part of the fraction with a boiling point of 350°C or less is extracted as a product, and then part or all of the remaining part (the fraction with a boiling point of 200 to 538°C) is hydrogenated to lighten it. After extracting the naphtha with a boiling point of 200°C or lower, the fraction with a boiling point of 350°C or higher is reduced to 25% or lower, and then recycled as a solvent. Note that hydrogenation was performed under the following conditions.

■TlH8V 1'(hr') ■Reaction temperature
420°C ■Pressure Reaction hydrogen pressure 1o o kg,/cr
T! (2) Catalyst Mo N+ -A40s Continuous operation was performed for 100 hours each using the above-mentioned methods C and D.

The results are shown in Figure 4 (a) and (b).

As is clear from Figure 4, in method C, the boiling point of the solvent is 6
The proportion of the fraction at 50°C or higher increases with time, and the liquid yield decreases accordingly1. On the other hand, in method D, the hydrogenated fraction M
By lightening with VC, the proportion of fractions with a boiling point of 350'C or higher in the solvent is controlled to 25% or less, and 47 to 4
A stable liquid yield of 8% (calculated as anhydrous charcoal) is obtained.

FIG. 5 shows the relationship between the proportion of fractions with a boiling point of 650° C. or higher in the solvent and the liquid yield in Method C. As can be seen from Figure 5, a liquid yield of 45% or more was obtained ((=boiling point 6 in the solvent).
The fraction at 50° C. or higher should be controlled to 25% or less, and to obtain a liquid yield of A0 or more, the fraction should be controlled to 65% or less.

Table 6 shows the composition of typical product oils obtained by method (1).

As described above, it can be seen that high yield and high quality products can be obtained by hydrogenating the solvent. Note that the product oil may be extracted before or after hydrogenating the solvent.

Effects of the Invention According to the present invention, heavy oil with a boiling point of 650° C. or lower can be obtained in high yield at a low pressure of 140 to 2001 cg/Cr/l, similar to the Bergius type.

[Brief explanation of drawings]

FIG. 1 is a schematic flowchart for implementing the present invention. FIG. 2 is a diagram showing the results of the coal liquefaction experiment of Example 1,
(a) is the case where method A is used, and (b) is the case where method 13 is used. FIG. 3 shows the relationship between the proportion of fractions with a boiling point of 650° C. or higher in the solvent and the liquid yield in Method A. FIG. 4 is a diagram showing the results of the coal liquefaction experiment of Example 2,
(a) is the case when the C method was used, and (b) is the case where the D method was used. FIG. 5 shows the relationship between the proportion of fractions with a boiling point of 50'C or higher in the solvent and the liquid yield in Method C. In addition, FIG. 2 and FIG. 4 show the proportion of fractions with a boiling point of 650° C. or higher in the solvent and the liquid yield when the solvent is used. Agent Patent Attorney Shun Tetsu Sasaki Figure 1 ↑ H: L Figure 2 (A) Operating sound (LV) Figure 2 (O) Open when operating (- Figure 3 Suki offing boil, Wataru 350'C or more Distillate ratio (%) Figure 4 Figure 4 (b) Darkness (hr)

Claims (4)

[Claims] (1) In a coal liquefaction method that uses coal, a solvent, a hydrogen-containing gas, and an iron-based catalyst and is carried out at a reaction hydrogen pressure of 2001 cg/cnt or less, the proportion of fractions with a boiling point of 550°C or higher in the solvent is reduced to 35% or less. Coal liquefaction method characterized by control. (2) The method according to claim 1, wherein the proportion of the fraction having a boiling point of 650° C. or higher is 25% or less. (3) Method 9 according to claim 1, in which the proportion of the fraction is controlled by extracting a part of the fraction with a boiling point of 350° C. or higher from the liquefied product out of the system as a product. (4) The method according to claim 1, wherein the proportion of the fraction in the liquefied product is controlled by hydrogenating part or all of the fraction with a boiling point of 200 to 568°C.