JPS59122590A - Liquefaction of coal - Google Patents

Abstract

PURPOSE:To obtain a liquid reaction product in high yield, by hydrogenating primarily in suspension of an iron catalyst, hydrogenating is further secondarily at high temperature, circulating partially the reaction products of the primary and secondary reactions through the primary hydrogenating reaction zone. CONSTITUTION:Coal is hydrogenated primarily in suspension of an iron catalyst at <=440 deg.C, a fraction having >=420 deg.C boiling point is collected, a fraction having 0.65-0.80 FA value is collected from the fraction, and circulated through the primary hydrogenating reaction zone. The residue fraction is hydrogenated secondarily at a higher temperature in suspension of a catalyst, to give the desired liquid reaction product. A fraction having >=420 deg.C boiling point and 0.65-0.80 FA value is collected from the reaction product and circulated through the primary reaction zone.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for liquefying coal, and in particular to a method for obtaining a liquid product from coal in high yield.

It is known to liquefy coal by hydrogenating it.

This technique can be broadly divided into one-stage method and two-stage method. The one-stage method involves slurrying coal together with a catalyst in a hydrocarbon solvent and liquefying it by hydrogenating it at high temperature and pressure for a long period of time. This method has problems in that it requires severe reaction conditions, consumes a lot of hydrogen, and produces a lot of gaseous products. On the other hand, the two-stage method is a method in which coal is first hydrogenated to form a liquefied product rich in heavy components, and then the heavy components are separated from this liquefied product and further hydrogenated. Although the process is complicated, the yield of liquid product is high.

The present invention relates to an improvement of the two-stage process, in which coal is subjected to primary hydrogenation in the presence of an iron-based catalyst to obtain a primary hydrogenation reaction product, from which a fraction with a boiling point of ≠20°C or higher is extracted. In the coal liquefaction method in which the fraction is fractionated and this fraction is further subjected to secondary hydrogenation, the primary hydrogenation is carried out in a suspended state of a catalyst at a temperature below 0°C, and the primary hydrogenation reaction The boiling point of the product is 2θ℃ or higher.”
2, and the fraction with an FA value of 0.65 to O, KO is separated and recycled to the primary hydrogenation reaction zone, and the secondary hydrogenation is carried out at a higher temperature than the primary hydrogenation. The process is carried out with the catalyst in suspension, and a fraction with a boiling point of ≠20°C or higher and an FA value of 0 to 0,000 is separated from the secondary hydrogenation reaction product. It is characterized by being circulated to the subsequent hydrogenation reaction zone.

To explain the present invention in detail, when producing a liquid material by the hydrogenation reaction of coal, generally speaking, when the reaction temperature is raised, the decomposition of the coal will proceed, but the production ratio of gaseous products will increase, so the hydrogen consumption will be reduced. Although the amount increases, the yield of liquid material increases. In order to reduce hydrogen consumption and increase the yield of liquid product, it is necessary to lower the reaction temperature without reducing the reaction rate.

According to the present invention, the reaction is carried out by using an iron-based catalyst and by circulating the fractions with FA values of o, t5 to 0, and 0, separated from the reaction product, to the primary hydrogenation reaction zone. Even at low temperatures, the reaction proceeds well and a liquid product can be obtained in high yield. Examples of the iron-based catalyst used in the primary hydrogenation in the present invention include iron oxide, iron sulfide, converter dust, red mud, iron ore, etc., but preferably finely pulverized iron ore is used. It is used after being modified with sulfur (see Japanese Patent Application No. 1983, T-JO 737). The amount of catalyst used is O1 as iron for anhydrous ash-free coal.
5 to 20% (by weight), preferably /-zO (by weight)%
It is. Incidentally, if desired, molybdenum, cobalt, nickel, etc. may be used in combination with the above-mentioned iron-based catalyst.

The primary hydrogenation reaction is l/-≠θ℃ or less, preferably 4to
o −+ lAo℃, hydrogen partial pressure! ; 0~! ;' 0
0 kg/CI? L.

Preferably 7! ~j 00 kVcri*. The reaction time is j-/20 minutes, preferably i0 to 70 minutes.

Coal is usually pulverized to 0'f 7" mm JJ, and the slurry is separated from the reaction product together with hydrocarbon solvent, circulating fraction, catalyst, etc./!? 0-≠20℃ distillate The amount of solvent used is (solvent + circulating fraction) based on anhydrous ash-free coal, 1.0~≠, O (weight) times, preferably 2.0 to 3.0 (weight) It's double.

Gaseous products are removed from the reaction product, and then distilled to obtain a light boiling fraction with a boiling point of igo℃ or less, a boiling point of ig'o~4t2θ
℃ solvent fraction etc. is distilled to obtain a fraction with a boiling point of 20℃ or higher, a part of which is used for the secondary hydrogenation reaction, and the other part is used in the primary hydrogenation reaction zone. circulates. This circulating fraction is F
A value must be 0.45-09g0. If a fraction having an FA value outside this range is circulated, the hydrogenolysis of coal will not progress satisfactorily. Therefore, in the primary hydrogenation reaction, the fraction with a boiling point ≠ 20°C or higher separated from the reaction product has an FA value of 0. A! It is preferable to perform this so that i~O0za0. If the FA value of this fraction is outside the range of 0.6~o, go, this fraction is further distilled to obtain FA.
The value is adjusted to 0.6j~o,go and used as a circulating fraction. The usage amount of this circulating fraction is based on anhydrous ash-free coal.
The total amount including the recycled fraction from the second hydrogenation step described later is 0.
i to 3 (weight) times, preferably 0.2 to 2.0 (weight)
It's double. Within this range, it is preferable for the reaction to proceed that the recycled fraction from the first hydrogenation step is larger than that from the second hydrogenation step. Incidentally, the fraction with a boiling point of 4t and 20°C or higher collected from the primary hydrogenation reaction product is usually
After the ash is removed through a deashing process, it is used for various purposes.

Addition is carried out with the catalyst in suspension. As a solvent, boiling point l♂0 fractionated from the reaction product as in the first stage hydrogenation.
-4' It is preferable to use a 20°C fraction. The amount of solvent used is 0.3 to 3.0 (
weight) times, preferably 0. j~! , 0 (weight) times. Further, as the catalyst, an iron-based catalyst similar to that used in the primary hydrogenation is used. The amount of catalyst used is 0° as iron for the fraction with a boiling point of 11-20°C or higher! -,20 (weight)%, preferably /~/θ (weight)%. Note that, as in the case of primary hydrogenation, it is preferable to modify with sulfur, and nickel, molybdenum, cobalt, etc. may be used in combination.

The secondary hydrogenation reaction needs to be carried out at a higher temperature than the primary hydrogenation reaction. As a result, the fraction with a boiling point of 20° C. or higher is easily decomposed and softened. Furthermore, even if the reaction is carried out at such a high temperature, only a small amount of gaseous products are produced. The conditions for the second hydrogenation reaction that are usually adopted are the reaction temperature 'A! ;0~
≠0℃, hydrogen partial pressure jO~SOO, preferably noj
The reaction time is 30 to 720 minutes, preferably 20 to 720 minutes.

Gaseous products are removed from the reaction product of the second hydrogenation reaction, and then distilled to remove light boiling fractions, solvent fractions, etc.
A fraction having a boiling point IA of 20°C or higher is separated and recycled to the primary hydrogenation reaction zone. Note that the FA value of this fraction is 0. Aj′
If the value is outside the range of ~01go, this fraction is further distilled to reduce the FA value to 0~0. It is adjusted so that it becomes zero and is circulated to the primary hydrogenation reaction zone.

According to the present invention, a liquid product can be obtained from coal in high yield.

The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited to the following examples unless it exceeds the gist thereof.

Note that the calculation of the FA value in the present invention is as follows.

Calculation method of FA value Calculate the ratio of carbon to hydrogen (0/H) by elemental analysis of the sample. Further, the ratio of hydrogen bonded to aromatic carbon (Har) is calculated using proton-NMH. From these analysis values, the FA value is calculated using the Braun-Ladner formula below.

[FA value is an index indicating the ratio of aromatic carbon in total carbon] In addition, in the following examples, parts and parts are parts by weight,
Means weight %.

Example 1 Australian Moel coal 700 crushed to 20θ mesh or less
(based on anhydrous ash-free coal), 1 g O part of coal liquefied oil with a boiling point of 10 to 20°C, and 1 t of separately prepared boiling point 20°C or higher F
10 parts of heavy distillate of coal liquefaction with an A value of 0.73, iron ore with an average particle size of 3μ corresponding to 5 parts of iron, and 1 part of iron.
7 and mixed with equimolar sulfur to form a slurry. This was placed in an autoclave, compressed with hydrogen, heated to ≠25°C, and heated to 20°C.
The primary hydrogenation reaction was carried out for 0 minutes at 0 kVcnLG. Gaseous products are removed from the reaction product and further distilled to produce water, boiling point/i, light boiling fraction below 0°C, boiling point/'g'
It was separated into a solvent fraction with a temperature of 0 to 11-20°C and a heavy fraction with a boiling point of 4t and 20°C or higher.

The yield of the product was as follows (based on anhydrous ash-free charcoal)
. Moreover, the FA value of the heavy fraction was 0.7/.

Water, - carbon oxide, carbon dioxide 2ta% C1-C5
Hydrocarbon ♂dilight boiling fraction
16 Solvent fraction 2/% Heavy fraction 30% Next, after deashing the heavy fraction, 60% solvent fraction on an ash-free basis and 5% iron ore as iron, and A mixture of equimolar sulfur and iron was placed in an autoclave, hydrogen was injected into the autoclave, and the temperature was 230 kg/pto℃.
cr? A second hydrogenation reaction was carried out with L and G for 60 minutes. The yield of the product was as follows (based on ash-free heavy distillate):
. Furthermore, the F and A values of the heavy fraction were 0.7ta.

Water Otsu Bun C1 to C5 hydrocarbons 12% Light boiling fraction Otsu solvent fraction 27% Heavy fraction jo% From the above results, the heavy fraction separated from the product of the primary hydrogenation reaction Of this, 30 parts are recycled to the primary hydrogenation reaction, the remaining 40 parts are used to the secondary hydrogenation reaction, and the heavy fraction separated from the secondary hydrogenation reaction product is recycled. By recycling the coal in the secondary hydrogenation reaction, all of the coal can be converted into a liquid or gaseous substance that is more than a solvent fraction. The yield of each product at this time is as follows (based on anhydrous ash-free charcoal).

Water, - carbon oxide, carbon dioxide 30% C1-C5
Hydrocarbons L5 light boiling fraction
2 parts% Solvent fraction ≠/% Comparative example 1 Australian Moel coal 700 crushed to 200 mesh or less
(based on anhydrous ash-free coal), 2'i'0 parts of coal liquefied oil (solvent fraction) with a boiling point of igo-ψ20°C, and iron ore with an average particle size of 3μ, which is equivalent to 5 parts of iron, and iron. The same mole of sulfur was mixed to form a slurry. This was put into an autoclave, hydrogen was injected under pressure, and the temperature was 4t2j℃, 200kg/ff.
The primary hydrogenation reaction was carried out at 1 G for 10 minutes.

The reaction results were as follows. The FA value of the heavy fraction was 0.73.

Water, -carbon oxide, carbon dioxide 22%01-C5
Hydrocarbons ﾅLight boiling fraction
10% solvent fraction 0% heavy fraction Next, after deashing the heavy fraction, 50% solvent fraction on an ash-free basis and 5% iron ore as iron, and Mix equal moles of sulfur to iron, charge it into an autoclave, pressurize it with hydrogen, and heat it at 11.30℃ and 230XJ.
When the secondary hydrogenation reaction was carried out for AO minutes at /cffl G, results similar to those of the secondary hydrogenation in Example 1 were obtained.

Therefore, the yields of products obtained by primary and secondary hydrogenation were as follows.

Water, -carbon oxide, carbon dioxide 2 φC1~C5
Hydrocarbons Light boiling fraction
74% Solvent fraction 7g% Heavy distillate 33% Patent applicant Mitsubishi Chemical Industries, Ltd. and others Hirona agent Patent attorney Yo Hase - 1 other person 2-1-1 Uchisaiwai-cho, Chiyoda-ku, Tokyo ■Applicant Japan Lignite Liquefaction Co., Ltd. 8-2 Marunouchi, Chiyoda-ku, Tokyo

Claims (1)

[Claims] (1) Coal is subjected to primary hydrogenation in the presence of an iron-based catalyst to obtain a primary hydrogenation reaction product, from which a fraction with a boiling point of 4L20°C or higher is separated, and this fraction is further processed into a second hydrogenation reaction product. In the coal liquefaction method for secondary hydrogenation, the primary hydrogenation is carried out at a temperature of ≠≠0℃ or lower with a catalyst in suspension, and the boiling point of the 7th hydrogenation reaction product is 1120℃ or higher. and the FA value is o,, t r
~0. separating and recycling the fraction which is O2 to the primary hydrogenation reaction zone; carrying out the secondary hydrogenation at a higher temperature than the primary hydrogenation in suspension of the catalyst; The secondary hydrogenation reaction product has a boiling point of ≠20℃ or higher and an FA value of 0~
A method characterized in that o and go fractions are separated and recycled to a primary hydrogenation reaction zone.