JPH05202365A - Simultaneous liquefaction of coal and plastics - Google Patents

Abstract

PURPOSE:To reduce the by-production of gases and organic residues and produce a liquefied oil rich in the light oil content having a high octane value by simultaneously decomposing coal and plastics in the presence of a catalyst at a specific temperature under a specified pressure in a hydrogen atmosphere. CONSTITUTION:Coal 1 is mixed with a circulated solvent 5 and a catalyst in a slurry state and fed together with hydrogen 3 into a reactor 7 through a preliminary heater 6. Plastics 2 are fed into the slurry which is prepared by mixing the coal 1 with the catalyst 4 and the circulation solvent 5, into a line between the preliminary heater 6 and the reactor 7 or directly into the reactor 7. In the reactor 7 the coal and the plastics are heated at 350-500 deg.C in a hydrogen atmosphere under 50-350 atmospheric pressure, and the liquefied product 8 is distilled to be separated into an oil fraction 9, a mixture 10 of gases with water and organic residues 11. A part of the oil fraction is used as the circulation solvent 5, thereby simultaneously liquefying the coal and the plastics to obtain the fuel having a high octane value and the liquefied oil suitable for chemical raw materials, etc., at low costs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for simultaneous liquefaction of coal and plastics, and more specifically, a liquid oil content suitable as a fuel having a high octane number and a high proportion of a light fraction and an aliphatic carbonization suitable as a chemical raw material. The present invention relates to a method for simultaneous liquefaction of coal and plastics, which makes it possible to obtain a liquefied oil containing a large amount of hydrogen such as alkane and alkene.

[0002]

2. Description of the Related Art The following three methods are conventionally known as methods for liquefying coal or plastics alone. (a) Coal reaction temperature of 400-600 ° C, maximum 700
A method of liquefying by reacting with hydrogen under atmospheric pressure.

(B) A method of liquefying plastics by thermally decomposing them in a nitrogen atmosphere under atmospheric pressure or reduced pressure while raising the temperature. (c) Coal reaction temperature of 800 to 1400 ° C, 20 to 3
A method for producing a synthesis gas by gasifying under a pressure of 0 atm and reacting the synthesis gas to synthesize a hydrocarbon. However, in the above method (a), it is necessary to use a large amount of expensive hydrogen, generate a large amount of gas, organic residue, etc., and have a low oil yield, and to add a large amount of an expensive catalyst. However, there is a drawback that the production cost of liquefied oil increases, and the obtained liquefied oil has a high content ratio of aromatic hydrocarbons when compared with petroleum, and also the hydrogenation reaction of coal with hydrogen. However, since it is an exothermic reaction, there is a drawback that a facility for cooling the liquefaction reactor is required during the reaction.

Next, in the above method (b), aliphatic hydrocarbons such as alkanes and alkenes are obtained as liquefied products, but a large amount of heat is required for the thermal decomposition, and this heat partially converts the raw material plastics. It has to be combusted or supplied from an external heat source, and further, the production yield of oil is low and the proportion of heavy fractions is large, and therefore there is a drawback that the production cost is increased.

Further, in the above method (c), the production yield of the oil component is higher than that in the above method (a), and in the produced liquefied oil, the content ratio of the aliphatic hydrocarbon, particularly alkane or alkene, is high. It is expensive and preferable for use as a chemical raw material, but the production process is complicated because it includes a two-step reaction process of production of synthesis gas and reaction of synthesis gas, and a large amount of gas is required when coal is gasified. Since the oxygen is supplied to partially oxidize the coal, the production cost of the liquid fuel is higher than that of the method (a), and the liquefied oil obtained by the method (c) has a low octane oil content. However, there is a problem in that the octane number must be increased by upgrading such as isomerization and alkylation.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for liquefying coal and plastic at the same time, and in combination with the above-mentioned conventional method for liquefying coal or plastic alone, hydrogen and It is possible to inexpensively produce a liquefied oil containing a large amount of oils and a large amount of aliphatic hydrocarbons, especially alkanes and alkenes, by using a simple production process with a small amount of catalyst and a high octane content and a high proportion of light fractions. It is to provide a possible method.

[0007]

According to the present invention, the above object is to provide coal and plastic at a reaction temperature of 350 to 500.
It is solved by a simultaneous liquefaction method of coal and plastic, which is characterized in that it is simultaneously decomposed in a hydrogen atmosphere in the presence of a catalyst at 50 ° C and a pressure of 50 to 350 atm.

In the present invention, the weight ratio of coal to plastic may be arbitrary depending on the types of coal and plastic, but it is preferable that the weight ratio of coal / plastic is 39/1 to 5/35. In principle, it is optimal to mix so that the calorific value of the hydrogenation reaction of coal with hydrogen and the calorific value of the thermal decomposition reaction of plastics cancel each other out.

The reaction temperature and the reaction pressure are somewhat different depending on the kinds of the raw material coal and plastic, but usually 3
It is in the range of 50 to 500 ° C and in the range of 50 to 350 atm. In the present invention, the coal may be bituminous coal, subbituminous coal or brown coal. In the present invention, the plastic is not particularly limited as long as it is a soft or hard solid or foam obtained by fluid-molding a polymerizable material or a polymer material at a specific stage of polymerization or processing, and is discarded. Plastic is also suitable as a target.

An iron-sulfur type catalyst is used as the catalyst, and as the iron-sulfur type catalyst, specifically, FeS ₂ ,
_{Fe 2 O 3 + S, Fe} (OH) 2 + S, red mud + S and iron ore + S, and the like. The amount of these iron-sulfur-based catalysts added is preferably 0.1 to 10 per coal of the raw material.
It is good to set it as wt%.

In the present invention, preferably, a part of the liquefied oil obtained by the liquefaction of coal is alkylated with an alkane or alkenes produced by the thermal decomposition of plastics to obtain a hydrocarbon with a high octane number in the final liquefied oil. In order to increase the content rate, it is effective to use an alkylation catalyst together with an iron-sulfur catalyst depending on the type of plastic.

As the alkylation catalyst, one or more catalysts selected from the group consisting of silica-alumina catalysts, solid phosphoric acid catalysts, aluminum chloride, hydrogen chloride, hydrogen fluoride and alumina are used. The addition amount of the alkylation catalyst is preferably 0.01 to 20 wt% with respect to the plastic as the raw material, but it may be used in the form of a fixed amount enclosed in the reactor.

The steps of the present invention will be described below with reference to the drawings. FIG. 1 is a process diagram showing an example of the method for simultaneous liquefaction of coal and plastic of the present invention. Coal 1
Is mixed with the circulating solvent 5 and the catalyst 4 in a slurry form,
It is sent to the reactor 7 through the preheater 6 together with hydrogen 3.

On the other hand, plastic 2 is coal 1, catalyst 4
And the circulating solvent 5 in the slurry, or the line between the preheater 6 and the reactor 7, or the reactor 7
Directly supplied to. In the reactor 7, coal and plastic are heated to 350 to 500 ° C in a hydrogen atmosphere,
It is pressurized to 50 to 350 atm and liquefied.

The liquefied product 8 liquefied in the reactor 7 and leaving the reactor 7 contains an oil component 9, gas + water 10 and an organic residue 11. Part of the oil content 9 (heavy oil content) is
It is separated by distillation and used as the circulating solvent 5. At this time,
In order to improve the performance of the circulating solvent 5, it is more effective to perform a hydrogenation treatment or a heavy n-alkane content removal treatment.

[0016]

EXAMPLES Examples of the present invention will be given below. Example 1 Coal, FeS ₂ , and a circulating solvent in a weight ratio of 2: 0.06: 6.
In the form of a slurry, and the waste plastic is added to the slurry in a ratio of 2 by weight, and the weight ratio of coal: FeS ₂ : circulating solvent: waste plastic is 2: 0.06: 6:
A mixture slurry of 2 was obtained, and coal, FeS ₂ , circulating solvent and waste plastic were added at 0.2 kg / hr and 0.00, respectively.
It was sent to the reactor through a preheater at flow rates of 6 kg / hr, 0.6 kg / hr and 0.2 kg / hr. Hydrogen was also similarly fed to the reactor at a flow rate of 500 l / hr.

In the reactor having an effective volume of 1 l, the fed coal and waste plastic were continuously decomposed at a reaction temperature of 450 ° C and a reaction pressure of 170 atm. The above operating conditions are shown in Table 1 below.

[0018]

Comparative Example For comparison, coal was liquefied by the conventional method. That is, the weight ratio of coal: FeS ₂ and the circulating solvent is 4 :.
The mixture was mixed in a slurry form at a ratio of 0.12: 6 and sent to the reactor through a preheater at flow rates of 0.4 kg / hr, 0.012 kg / hr and 0.6 kg / hr, respectively. Hydrogen was likewise fed to the reactor at a flow rate of 500 l / hr.

The coal fed in the reactor having an effective volume of 1 l was continuously decomposed at a reaction temperature of 450 ° C. and a reaction pressure of 170 atm. The operating conditions were the same as the above-mentioned method for simultaneous liquefaction of coal and waste plastic except for the amount of raw material and the amount of catalyst supplied. The operating conditions are shown in Table 3 below.

[0021]

Component composition and heat of reaction of the product produced by the simultaneous liquefaction method of coal and waste plastic of Example 1 above, and component composition and reaction heat of the product produced by liquefaction of coal by the conventional method of the above Comparative Example. Are shown in Table 4 in comparison.

[0023]

From Table 3 above, the simultaneous liquefaction method for coal and waste plastic according to the present invention improves the yield of oil production as compared with the conventional coal liquefaction method.
The production yield of gas + water and organic residue is reduced, the amount of hydrogen consumed during liquefaction is reduced, and the light oil having a boiling point of 220 ° C or less is increased in the produced oil, and fat is reduced. It is clear that the amount of group hydrocarbons, especially alkanes and alkenes, increases and that the reaction heat in the reactor is on the endothermic side (ideally ± 0 is good).

That is, the simultaneous liquefaction method of coal and waste plastic according to the present invention has a H
/ C ratio (hydrogen and carbon content ratio) is 0.6-
1.1, but 1.5-for waste plastic
Since it is as high as 2.0, the amount of hydrogen consumed per liquefied oil produced is small, and the yield of liquefied oil due to thermal decomposition of waste plastic under high temperature and high pressure is higher than that of liquefied oil due to liquefaction of coal. Moreover, since the thermal decomposition of the waste plastic is performed under high temperature and high pressure, the production rate of gas and organic residue can be reduced and the light oil content in the liquefied oil can be increased.
Further, not only the amount of the FeS ₂ catalyst added per liquefied oil produced can be reduced, but also the heat of reaction of coal liquefaction is used for the thermal decomposition of waste plastic, so that the heat of the reactor can be removed.

[0026]

As described above, in the method for simultaneous liquefaction of coal and plastic of the present invention, coal and plastic are
When simultaneously liquefied in the presence of a catalyst, a catalyst such as an iron-sulfur-based catalyst mainly promotes liquefaction of coal, and because the liquefaction reaction of coal is an exothermic reaction, liquefaction of coal causes
Thermal energy is supplied for the thermal decomposition of the plastic, and the plastic is thermally decomposed to produce aliphatic hydrocarbons. And, since this aliphatic hydrocarbon alkylates a part of the liquefied oil generated by the liquefaction of coal, oil with a high octane number and liquefied oil with a high content of aliphatic hydrocarbons, especially alkanes and alkenes, are obtained. Be done. That is, the heat of decomposition required for the thermal decomposition of plastics can be covered by the reaction heat of coal liquefaction, so that the thermal efficiency is high and the economy is excellent. Also, since the thermal decomposition of plastics is performed at high temperature and high pressure, the formation of gas and organic residue is generated. Is reduced, and liquefied oil having a high content of light oil can be produced, and this liquefied oil can be used as a liquid fuel having a high octane number. In addition, aliphatic hydrocarbons, especially alkanes and alkenes, can be used as chemical raw materials if they are separated. Further, in the present invention, coal and plastic can be liquefied at the same time, so that the operating cost of equipment can be reduced. Also, especially, since waste plastic is cheaper than coal, raw material cost can be reduced.

[Brief description of drawings]

FIG. 1 is a process drawing showing an example of the method for simultaneous liquefaction of coal and waste plastic of the present invention.

[Explanation of symbols]

 1 Coal 2 Plastic 3 Hydrogen 4 Catalyst

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Tsukui 1 Yawata Kaigan Dori, Ichihara City, Chiba Mitsui Engineering & Shipbuilding Co., Ltd. Chiba Works

Claims (1)

[Claims] 1. Coal and plastic are reacted at a reaction temperature of 350.
A method for simultaneous liquefaction of coal and plastics, characterized in that they are simultaneously decomposed in a hydrogen atmosphere in the presence of a catalyst at ˜500 ° C. and a pressure of 50 to 350 atm.