JPS5849791A - Gasification of coal - Google Patents

Abstract

PURPOSE:To obtain a synthesis gas in high gasification efficiency, by blending crushed coal with water, a dispersant and a gasifying agent sufficiently to give a highly concentrated slurry, feeding it to a gasification furnace. CONSTITUTION:Raw material coal is previosly granulated into <=about 10mm., and pulverized by the wet type crusher 1 to 200 meshes and a transmittance of about 10-80%. The pulverized coal, a gasifying catalyst, water and a foaming dispersant or a dispersant having an action to reduce slightly the surface tension of water are fed to the blender 2, and kneaded fully, to give a slurry having flow characteristics and a concentation of about 60-90wt% on dry base. The slurry is stored once in the collecting tank 3, and sent by pressure to the gasification furnace 5 by the pump 4. The slurry is jetted together with oxygen and steam, and gasified at about 1,100-1,700 deg.C at about 10-70atm.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention makes raw coal into a slurry with a high concentration of 60 to 90 <, and supplies it to a gasifier after uniformly dispersing a gasification catalyst to obtain synthesis gas with high gasification efficiency. The present invention relates to a coal gasification method that can be used to gasify coal.

Conventionally, in the process of partially oxidizing coal to obtain synthesis gas, a wet feeding method has been proposed in which raw coal is pulverized to prepare a coal/water slurry and then fed to a gasifier.
Since the slur+J- concentration is as low as 50% or less, a large amount of water is evaporated in the gasifier, resulting in a problem of low gasification efficiency.

As a result of extensive research in order to solve the above problems, the present inventors have found that a mixture of pulverized coal and a small amount of water has a foaming dispersant or a surface tension of water slightly (0.1 to 5 d"/ ne/
When a dispersant that has the effect of reducing an) is added and thoroughly mixed, 1. When a foaming dispersant is added, the bubbles generated are interposed in the coal particle layer, resulting in fluidity.
When a dispersant that slightly lowers the surface tension of water is added, the water adheres uniformly to the surface of the coal particles, making it easier for the coal particles to slip on each other, creating fluidity. It has been found that by adding the catalyst, the catalyst can be uniformly dispersed and the gasification efficiency can be improved.

The present invention has been made in view of the above points, and includes a method of supplying coal to a gasifier, partially oxidizing the coal, and obtaining synthesis gas, by thoroughly mixing pulverized coal, water, a dispersant, and a gasification catalyst. Coal 60-90 with gasification catalyst uniformly dispersed
This book attempts to provide a method for gasifying coal with higher gasification efficiency by preparing a highly concentrated slurry of a wide range and supplying this highly concentrated slurry to a gasification furnace.

Hereinafter, the configuration of the present invention will be explained based on the drawings.

FIG. 1 shows an example of an apparatus for carrying out the method of the invention. After raw material coal (either coking coal or non-caking coal) is crushed in advance to about IQgl or less, it is further crushed by a dry pulverizer 1 to a 200 mesh passing rate of about 10 to 80, preferably 30 to . Finely grind to 70%. The pulverized coal, gasification catalyst, water, and a foaming dispersant or a dispersant that has the effect of slightly lowering the surface tension of water are supplied to the kneader 2 and sufficiently kneaded to form a fluid, highly concentrated slurry. prepared. The amount of dispersant added at this time is 0.01 to 3 weight range relative to coal, preferably 0.3 to 1.5 weight range, and the concentration of the slurry (coal content) is 60 to 90 on a dry basis. Weight range, preferably 65-80% by weight
It is. Also, the viscosity of this slurry is 300 to 3000
c, p.

The gasification catalyst used in the present invention includes:

Suitable materials include iron and other group I metals of the periodic table, or 1M potash earth metals of group a of the periodic table.

These metals are added in the form of seminates, chlorides, sulfates or oxides along with water during slurry preparation.

Further, the foaming dispersant used in the present invention is as follows.

γ-ionic, nonionic, cationic surfactants, etc. may be used alone or in combination, and are appropriately selected depending on the type of coal. Specifically, anionic surfactants include alkylbenzene sulfonates, γ-alkyl sulfate ester salts, polyoxyethylene alkyl V (alkylphenol) sulfate ester salts, alkyl phosphate ester salts, dialkyl sulfosuccinate ester salts, acrylic acid or / and maleic anhydride copolymer-polycyclic aromatic group 7
Lephonides or ho-Vmarin compounds are used,
As the cationic surfactant, γ-alkylamine salt-quaternary amine salt, etc. are used, and as the monoionic surfactant, polyoxyalkyl ether 1L/, polyoxyethylene alkylphenol ether, oxyethylene/oxypropylene block, etc. are used. Polymer, polyoxyethylene alkylamine, sorbitan fat, fatty acid ester,
Polyoxyethylene so-V bitane fatty acid esters are used, and as amphoteric surfactants, furkyl betaine and the like are used, and fta1,2.8 monoamines are used.

Amine compounds such as diamines are used. In addition, as the dispersant that has the effect of slightly lowering the surface tension of water used in the present invention, 7-ionic, nonionic, cationic surfactants, etc. may be used alone or in combination, and carbon It is selected appropriately depending on the species. Specifically, anionic surfactants include fatty oil sulfate salts,
Higher alcohol sulfate salts, nonionic ether sulfate salts, olefin sulfate salts, alkylaryl sulfonates, dibasic acid ester sulfonates, dialkyl sulfosuccinates, γ-silsarcosinates, etc. are used. As a surfactant, 1. Polyoxyethylene fatty acid ester.

Aliphatic alcohol polyoxyethylene ether - alkylphenol polyoxyethylene ether.

Polyhydric alcohol fatty acid esters, ethanolamite of fatty acids, etc. are used, and as cationic surfactants, amphoteric ammonium chloride, γV kyldimethylbenzyl ammonium chloride, 7M kylpyridinium salt, etc. are used. As the surfactant, higher γ-alkyl amino acids and the like are used.

The slurry prepared by the mixer 2 is once stored in the collect tank 6, and then pumped by the high-pressure slurry pump 4 at a linear velocity of 0.5 to 5 m/sec, preferably 2 to 4 m/sea.
The water is then pressure-fed to the gasification furnace 5 and gasified while flowing downward inside the oxygen-water sulfurization furnace 5.

The temperature in the gasifier 5 is 1100-1700"C1, preferably 1400-1600°C, and the pressure is 1'0-g
□ ATM Ic is maintained. When the slurry is ejected into the gasifier 5, there is almost no aggregation between coal particles, and it has good dispersibility and quickly mixes with oxygen, gasifying with high gasification efficiency and mainly producing hydrogen and carbon oxides. It is converted into syngas as a component. The main reaction formula at this time is as follows.

C+ 2 H, →CH4 C+ H20→CO+H.

C-4-2H, O→Co, +2H++ c -4-co, →2c.

Co-1-H, O → Co, +L C+0. →CO.

2C+O, → 2c.

Note that 6 is a lock hopper, 7 is a waste heat boiler, and 8 is a settling tank.
9 and 10 are heat exchangers.

FIG. 2 shows another example of an apparatus for carrying out the method of the invention. That is, raw coal is crushed in advance to approximately 1011 particles or less, and then supplied to the wet crusher 11.

At the same time, a water 1 dispersant and a gasification catalyst are added, and the raw coal is pulverized in the wet pulverizer 11, and the raw coal-water 1 dispersant and gasification catalyst are sufficiently kneaded to create a fluidized mixture in which the catalyst is uniformly dispersed. Prepare a highly concentrated slurry. The coal particle size after pulverization is 200 mesh passing rate 10-80% - preferably 30-70%, and the viscosity of the slurry at the exit of the wet pulverizer 11 is 300-aooo
c, p.

The other configurations are the same as in the case of FIG.

Next, embodiments of the present invention will be described.

Example 1 After pre-crushed Australian sub-bituminous coal.

It was ground by a dry grinder. This degree of grinding, water.

Dispersant that lowers the surface tension of water (1.0 for coal
% by weight) and gasification catalyst were supplied to a mixer and kneaded for 10 minutes to prepare a highly concentrated slurry. F as a gasification catalyst
Using S03 -re weight is 0.5% by weight based on coal
It was added so that The properties of the Australian sub-bituminous coal were as follows.

Moisture 7.0 Muscle ash 7.1% Volatile content 26.2 Fixed carbon 59.7% Fuel ratio 2.27 The slurry at the exit of the kneader has a particle size of 1w or less.
25% mesh passing rate, slurry? The JI degree was 70<(dry base), and the viscosity was 14QOc, p. This slurry was then supplied to a gasifier and gasified by blowing in an oxidizing agent and oxygen at a pressure of 25 atm and a temperature of 1400°C. The composition of the resulting gas was as follows.

H, 87, 1 Go 46.8% Co, 16.0% N, 0.4 Curse CH, 0.08 Width H, S 0.18% Example 2 After preliminarily crushing sub-bituminous coal from China , ground by dry grinder. The pulverized coal-water 1 foaming dispersant (1.0% by weight based on the coal) and the gasification catalyst were supplied to a mixer and sufficiently kneaded to prepare a highly concentrated slurry. Fe and O were used as gasification catalysts.

It was added in an amount of 1.0% by weight based on the coal. The properties of the sub-bituminous coal produced in China were as follows.

Moisture 7.2 Ash content 8.9 Volatile matter 28.2 % Fixed carbon 60.0 < Fuel ratio 2.13 The properties of the slurry at the exit of the kneader are 2 with a particle size of 1 jls or less
00 mesh passing rate was 30 times, slurry concentration was 76% (dry base), and viscosity was 890c, p. Next, this slurry was supplied to a gasifier, and the pressure was 10 atm and the temperature was 1
It was gasified by blowing oxygen as an oxidizing agent at 400°C. The composition of the resulting gas was as follows.

H,' 85.2% CO52.1 Go, 12.8% N, 0.30% CH, 0.04% H, SO, 02% As explained above, according to the method of the present invention.

Because the slurry concentration is high, the drop in gasification efficiency due to water evaporation is small, and by adding a gasification catalyst to the water during slurry preparation.

Since the catalyst can be uniformly distributed in the slurry, the gasification efficiency can be increased and the amount of catalyst added can be reduced.

[Brief explanation of drawings]

FIG. 1 is a flow sheet showing an example of an apparatus for carrying out the method of the present invention, and FIG. 2 is a flow sheet showing another example. DESCRIPTION OF SYMBOLS 1...Dry crusher-2...Kneader, 6...Collect tank, 4...High pressure slurry pump, 5...Gasifier. 6... Lock hopper, 7... Waste heat boiler 8...
Sedimentation tank. 9-10...Heat exchanger, 11...Wet crusher Patent applicant Kawasaki Heavy Industries, Ltd.

Claims (1)

[Claims] 1. Pulverized coal in a method of supplying coal to a gasifier and partially oxidizing the coal to obtain synthesis gas. The feature is that a water-dispersant and a gasification catalyst are thoroughly mixed to prepare a highly concentrated slurry of 60 to 90% coal in which the gasification catalyst is dispersed, and this highly concentrated slurry is supplied to a gasification furnace. Coal gasification method.