JPS6150995B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for producing low sulfur gas and coke to be supplied to a steam generator from coal.

Unfired or only slightly fired coal is gasified in a chamber under pressure, during which time
It is known that gases with low calorific values are generated (on average less than 2500 kcal/m3). This gas is either combusted as a combustion gas in a steam generator or gas turbine, or purified to synthesis gas by removing certain gas components, or purified to natural gas by separating out the methane component. It is made into a high calorific gas with similar properties. As is known, for gasification it is necessary to apply heat, which in known devices is produced by burning a part of the coal to be gasified with air. You can get it. however,
Since air contains a lot of nitrogen, the calorific value of the gas obtained by gasification is greatly reduced by partially burning the coal.

In order to eliminate this crucial drawback, it is also known to use water vapor as gasification medium instead of air. However, in this case,
It is necessary to supply gasification heat externally.
In this coal gasification method (water gas), the calorific value of the gas produced is low, on the order of 2500 to 3000 kcal/m3. This method has the disadvantage that if the gasifier is small,
It is difficult to supply a relatively large amount of gasification heat from the outside. It is also known to supply the heat of gasification from a high temperature reactor.

In known devices that utilize gas for power generation and gas supply, the individual device parts are connected one after the other and cannot be separated, with the result that if the gas generator is not in operation, the power generation is not possible. There is also no gas supply. Another decisive disadvantage is that the entire amount of gas generated must be desulphurized in order to be able to use the end product, such as the flue gas of a steam generator, which pollutes the environment. . A very particular drawback is that in the known gasification processes only uncalcined or only slightly calcined coal can be used, so that necessarily only a small fraction of the total coal fraction is available. It's nothing more than that.

Starting from these critical drawbacks, such as the inability to separate the equipment parts, the need for a large gas sulfur flow, and the restriction to specific coals, the present invention proposes The object of the invention is to eliminate the above-mentioned conventional drawbacks in a device for producing gas and coke from coal to be fed to a steam generator.

To achieve this objective, an apparatus according to the invention comprises: (a) a device for crushing coal into powder coal, connected to a first pneumatic system using flue gas from a steam generator as carrier gas; a crushing device; (b) a preoxidizer coupled to the crushing device for preoxidizing pulverized coal from the crushing device with hot air; and (c) preoxidizing the pulverized coal from the air from the preoxidizer. An air/air system connected to a pre-oxidizer to separate the pulverized coal
a coal separator; (d) degassing and/or gasification of the preoxidized and separated pulverized coal to be accomplished by heat carrier gas from a gas heater to produce gas and coke; , a reaction chamber connected to an air-coal separator; (e) a gas-coke separator connected to the reaction chamber for mutually separating coke and gas from the reaction chamber; and (f) a gas-coke separator connected to the reaction chamber. (g) an intermediate sump connected to the coke side of the gas-coke separator for receiving the coke separated from the gas in the coke separator; and (g) an intermediate sump for conveying the coke from the intermediate sump to the steam generator. a second pneumatic system using the active gas as a carrier gas; and (h) connected to the gas side of the gas-coke separator for separating tar and residual coke from the gas from the gas-coke separator. a tar and coke separator; (i) a heat exchanger coupled to the tar and coke separator for cooling the gas from the tar and coke separator; and (j) the cooled gas in the heat exchanger. and a hydrogen sulfide washer connected to a heat exchanger for washing off hydrogen sulfide from the heat exchanger.

In summary, the device of the present invention having such characteristics has the following advantages and features (1) to (7).

(1) Sulfur contained in coal transfers as hydrogen sulfide to the gas produced in the reaction chamber and separated from coke in the gas/coke separator, and this gas is subjected to desulfurization, that is, hydrogen sulfide removal. It is not necessary to convert the entire coal to gaseous form for desulfurization. It should be noted that the gas obtained in the reaction chamber of the device according to the invention contains only hydrogen, hydrocarbons, relatively small amounts of carbon monoxide, and hydrogen sulfide.

(2) No special requirements are necessary for coal. Any coal can be used, including lignite.

(3) The steam generator in the device of this invention can be used to drive a steam power generation device of thermal power generation equipment, and in that case, the gas obtained by the device of this invention can be used to drive a gas turbine that can be attached to the steam power generation device. Can be used in the system. This results in thermodynamic advantages of the thermal power plant, resulting in higher efficiencies than can be obtained with conventional thermal power plants, and further reducing their investment costs.

(4) The gas obtained with the device of the invention can be used as an industrial gas, e.g. synthesis gas, in the chemical industry and for the reduction of ores, but it can also be used, in part, as a high-calorific gas, in general It can be fed into the city gas supply network.

(5) The ash contained in the coal is combined into the coke produced in the apparatus of the invention and sent to the steam generator. This ash can be removed as a particulate residue, for example, during the combustion of coke in a steam generator.

(6) In the apparatus of the present invention, the steam generator can be constructed so that it can be operated while being disconnected from other components such as the reaction chamber and the hydrogen sulfide scrubber. Therefore, for example, a thermal power generation facility equipped with a steam generator can be built early, taking into account the later introduction of reaction chambers, hydrogen sulfur scrubbers, etc., and can initially be constructed using coal with a low sulfur content. I can drive.

(7) The hydrogen sulfide washed away by the hydrogen sulfide cleaner is
Can be used to produce elemental sulfur. This sulfur can, for example, be conveyed back to the mine together with the granulated coal slag from the steam generator for void filling, in molten state, in granular or pulverized form.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In the embodiment shown in FIG. 1, coal 1 supplied from a coal mine or a coal stockyard is put into a coal reservoir 2, and is then sent to a coal crusher 4 by a coal feeder 3. . A first pneumatic system 6 is connected to this crushing device 4 . The first pneumatic system 6 uses the flue gas discharged from the steam generator 29 of the thermal power generation equipment as a carrier gas, and the flue gas of the first pneumatic system 6 is supplied to the preliminary oxidizer 8 depending on the case. After passing through, it reaches the crushing device 4. The pulverized coal produced by the pulverization in the pulverizer 4 is conveyed to the steam separator 5 by the flue gas of the first pneumatic system 6 . In this case, the moisture contained in the pulverized coal is evaporated by the flue gas into steam, which is separated from the pulverized coal in the steam separator 5 and, together with the flue gas,
As shown by reference numeral 7, it is discharged to the outside.

The powdered coal from which moisture has been separated and removed in the steam separator 5 is
Preoxidation is carried out in a preoxidizer 8, for example an instant oxidizer. This preoxidation is carried out in this embodiment by air 9, which is carried by a blower 33 and heated to a high temperature by an air heater 31 attached to the steam generator 29.
achieved by. Of course, the air heater 31 may be located outside the steam generator 29. An air/coal separator 10 is connected to the preoxidizer 8, and the preoxidized pulverized coal is transferred from the preoxidizer 8 to the air/coal separator 10 by the remainder of the air 9.
The air is separated from the pulverized coal. This separated air is conveyed via passage 11 to the combustion chamber of steam generator 29 . A part of the pulverized coal is guided along with this air, but this pulverized coal is
The separation efficiency of the air-coal separator 10 is not very important since it is burned for steam production in the combustion chamber and therefore there are no losses.

The pulverized coal separated from the air is fed into a reaction chamber 12 connected to an air/coal separator 10. In this reaction chamber 12, a process consisting of degassing and/or gasification of the powdered coal is performed. This process is carried out by a blower 28 passing through a gas heater 30 attached to a steam generator 29 into the reaction chamber 1.
This is achieved by a heat-carrying gas 27 flowing into 2. The gas heater 30 is, of course, the steam generator 2
9 or heating may be achieved by other heat carriers. In the process in the reaction chamber 12, steam can be blown into the mixture of pulverized coal and heat carrier gas when it is necessary to increase the gas yield, ie when a part of the carbon has to be additionally gasified.

In the reaction chamber 12, gas and coke powder are produced by said treatment of the pulverized coal, which are separated from each other in a gas-coke separator 13 connected to the reaction chamber 12. The coke powder separated from the gas in the gas-coke separator 13 is stored in an intermediate reservoir 14 connected to the coke side of the gas-coke separator 13, and is passed from the outlet 15 of the intermediate reservoir 14 to the second pneumatic system. 16,
17 through the coke passage 17 to the steam generator 2
9. In the second pneumatic systems 16, 17, an inert gas, for example a flue gas, is used as carrier gas. If flue gas is used, this flue gas is drawn off behind the electric filter 35;
Through the blower 37 and the passage 16, the outlet 1
5, from which it is used to transport the coke powder along the coke path 17. The quality of separation of gas and coke in the gas-coke separator 13 is decisive for the separation effect in the tar-coke separator 19, which will be described later.

A tar-coke separator 19 and a waste-heat heat exchanger 20 are connected in sequence to the gas side of the gas-coke separator 13, preferably via a waste-heat steam generator 18. The gas separated in the gas-coke separator 13 is preferably cooled in a waste heat steam generator 18 to a temperature range favorable for tar separation before reaching the tar-coke separator 19. In the tar and coke separator 19, tar and residual coke are separated from the gas, and if the separated tar and residual coke are not used for product formation, they are passed through a passage 39 to a steam generator 29.
transported to. The gas from which tar and residual coke have been removed in the tar/coke separator 19 is further cooled in the waste heat exchanger 20 . Waste steam generator 18 and waste heat exchanger 20
The heat removed from the gas in is transferred to the steam power generation device 43 of the thermal power generation facility.

The heat exchanger 20 is provided with a gas compressor 21 .
A hydrogen sulfide washer 22 is connected, and the gas cooled by the heat exchanger 20 is compressed by a gas compressor 21 and then reaches the hydrogen sulfide washer 22 . here,
Hydrogen sulfide is separated from the gas by scrubbing and is converted to sulfur in the Claus device 23. This sulfur is granulated by a sulfur granulator 24 and then sent to a sulfur reservoir 25. In this way, gas with low sulfur content can be obtained from the hydrogen sulfide scrubber 22.

The gas obtained from the hydrogen sulfide scrubber 22 is sent to a device 26 for separation of relatively high-grade hydrocarbons, if necessary.
After doing this, you can use it freely. This gas can be removed as synthesis gas or methane, as shown at 48, or for conversion to another substance by steam and heat. This gas can also be fed to a directly coupled turbine system consisting of an air compressor 44, a combustion chamber 45 and a gas turbine 46. In the combustion chamber 45 of this turbine system,
A portion of the gas is combusted and the remaining gas enters the steam generator 29 through passage 47, with a large amount of excess air remaining which is fed into the turbine system.

The ash separated in the electric filter 35 attached to the steam generator 29 is fed back into the steam generator 29 through the passage 38 and is melted in its melting chamber (not shown), after which it is It is extracted in the form of granules as is customary. This granular ash passes through a reservoir 41 and, as shown at 42,
Together with the granular sulfur from the sulfur reservoir 25, it is returned to the mining site of the mining site. In addition, 32 is a feed water heater,
34 is a condensate heater, and 36 is a flue gas outlet.

[Brief explanation of the drawing]

FIG. 1 is a diagram representing an embodiment of the device of the invention. In the figure, 4 is a crushing device, 6 is a first pneumatic system, 8 is a preliminary oxidizer, 9 is high temperature air, 10 is an air/coal separator, 12 is a reaction chamber, 13 is a gas/coke separator, and 14 is a Intermediate reservoir, 16 and 17 are the second pneumatic system,
19 is a tar coke separator, 20 is a heat exchanger, 22 is a hydrogen sulfide scrubber, 27 is a heat carrier gas,
29 is a steam generator, and 30 is a gas heater.

Claims (1)

[Claims] 1. In an apparatus for producing a gas with a low sulfur content and coke supplied to a steam generator from coal, (a) flue gas from the steam generator 29 is used as a carrier gas; (b) a pulverizer 4 for pulverizing coal into powdered coal, connected to the first pneumatic system 6 used; (b) for pre-oxidizing the pulverized coal from the pulverizer 4 with hot air 9; (c) an air-coal separator 10 connected to the preoxidizer for separating preoxidized pulverized coal from the air from the preoxidizer 8; and (d) degassing and/or gasifying the pre-oxidized and separated pulverized coal using a gas heater 30.
(e) a reaction chamber 12 connected to the air-coal separator 10 for producing gas and coke by means of a heat-carrying gas 27 from the reaction chamber 12; (f) a gas-coke separator 13 connected to the reaction chamber for separating the coke from the gas;
an intermediate sump 14 connected to the coke side of the coke separator; (g) a second pneumatic transfer station 16 using an inert gas as carrier gas for conveying coke from the intermediate sump 14 to the steam generator 29; 17 and (h) from the gas from the gas-coke separator 13,
a tar-coke separator 19 connected to the gas side of the gas-coke separator for separating tar and residual coke; (i) a tar-coke separator 19 for cooling the gas from the tar-coke separator 19; a heat exchanger 20 connected to the coke separator; and (j) a hydrogen sulfide scrubber 22 connected to the heat exchanger for scrubbing hydrogen sulfide from the gas cooled in the heat exchanger 20. A gas and coke production device characterized by: 2. The manufacturing apparatus according to claim 1, wherein the gas heater 30 is attached to the steam generator 29. 3 The second pneumatic systems 16 and 17 are connected to the steam generator 2
3. The production device according to claim 1, wherein the flue gas from 9 is used as carrier gas.