DE102009035407A1 - Integration of coal mill drying, coal injection and coal gasification for entrained-flow gasification plants - Google Patents

Abstract

In a device for fuel mill drying and fuel feed for an entrained flow gasification plant in which a fuel dust is gasified at a pressure between 0.1 and 1 MPa (1 and 10 bar) to a rich in H and CO containing crude gas, a device (3) for Grinding and drying of the raw fuel to combustible dust, a dust filter (4), a Brennstaubsilo (5), a lock (6 *) with promotion to the pressure of entrained flow gasification plant, a feed tank (9) and an entrained flow gasification plant (10) connected directly in series. In contrast to conventional devices, the process steps of coal preparation and production through integration are minimized and thus the required effort is significantly reduced.

Description

The The invention relates to a device for fuel mill drying and fuel feed for an entrained flow gasification plant, in which a dust at a Pressure between 0.1 and 1 MPa (1 and 10 bar) to a rich in H and CO containing raw gas is gasified.

In order to be able to gasify coal by means of entrainment gasification with dry coal feed, it is necessary to dry and grind the coal and to raise the coal, including conveying gas, to the gasification pressure. This is done according to the current state of the art in the following, essential process steps, see 1 , The raw coal is conveyed via suitable conveyor technology ( 1 ) a raw coal silo ( 2 ) and passes from there into the grinding drying plant ( 3 ). Depending on the water content of the coal, the drying and grinding steps can be combined in the mill or carried out separately using the coal dryer and coal mill. The generated coal dust is filtered through a filter ( 4 ) in a coal dust silo ( 5 ) stored. From there, the coal is conveyed via a pneumatic conveying system ( 6 ) into an intermediate bunker ( 7 ). From there, the coal passes through a lock system ( 8th ), in which the coal is pressurized, into a feed tank ( 9 ), from where the coal in turn pneumatically the air flow gasifier ( 10 ) is supplied.

The process steps ( 1 ) to ( 7 ) run at atmospheric pressure or only slight overpressure to overcome transport pressure losses. The process steps ( 9 ) and ( 10 ) run at high pressures, typically between 1 and 10 MPa (10 and 100 bar). The lock system ( 8th ) works with periodically changing pressures between gasification process pressure and atmospheric pressure of the intermediate bunker ( 7 ).

The entire process chain of coal processing from raw coal to to Flugstromvergaser represents a significant proportion of the effort for one Coal gasification plant. For High rank coal such as hard coal, anthracite, petroleum coke This method also competes with the slurry gasification, wherein the slurry gasification with respect to the investment costs usually at an advantage stands.

The invention is based on the object, the effort for Brennstoffmahltrocknung and fuel feed for a entrained flow gasification plant ( 10 ) significantly reduce.

The The object is achieved by a device having the features of the claim 1 solved.

According to the invention the process steps of the coal preparation and promotion by integration minimized and thus significantly reduces the required effort.

2 shows the main process steps of coal preparation and promotion according to the present invention. Compared to the state of the art, the process step ( 6 * ) while the function of the lock system ( 8th . 1 ) and pneumatic transport ( 6 . 1 ). The intermediate bunker ( 7 . 1 ) completely omitted.

advantageous Further developments of the invention are specified in the subclaims.

The Invention is hereinafter referred to as an exemplary embodiment in a for understanding required extent explained in more detail with reference to figures. Showing:

1 Essential process steps of coal preparation and production for entrainment gasification with dry feed according to the state of the art,

2 Substantial process steps of the coal preparation and conveying for the entrainment gasification with dry feed according to the present invention,

3 the treatment of flash gas and excess gas quantities and

4 the return of the filter cake from the raw gas purification plant in the coal mill drying.

In the same designations denote the same elements.

The main difference between the pneumatic conveying system ( 6 . 1 ) and the combination ( 6 * ) of lock and pneumatic conveying is the pressure. While the pneumatic delivery requires only low pressures - usually 1.5 to 3 bar, the pressure is increased and combined with the gasification process pressure 1 to 10 MPa (10-100 bar), including the pressure loss of the pneumatic conveying this pressure into the feed tank ( 9 ) realized. In addition to the execution of ( 6 * ) as a combination of lock with pneumatic conveying the use of a dust pump is also possible.

A development of the invention is characterized by in 3 Dashed treatment treatment of expansion and / or excess gas given.

Both at the lock release as also due to the pneumatic transport of ( 6 * ) to ( 9 ) must be removed in some cases large amounts of gas. These could conventionally be dedusted in separate filter systems. In the integration of coal mill drying and coal gasification, it is possible, the amount of gas produced in the already existing filter ( 4 ) to dedust and thus save additional effort. For this purpose, the gases, such as nitrogen or carbon dioxide, must be throttled from the process pressure to atmospheric pressure and, depending on the type of gas, temperature conditions and the risk of dew point falls below a gas preheating of the gas quantities.

In a further embodiment of the invention, the filter cake (wholly or partially), which in the raw gas purification ( 11 ) of the gasification process is obtained (dash-dot line) in the raw coal silo 2 recycled. As a result, the plant efficiency can be increased (repeated gasification of unreacted carbon) and disposal costs are minimized.

• – Wegfall des Zwischenbunkers (7, 1)
• – Reduzierung der Bauhöhe des Einspeisesystems
• – Integration von Schleuse und pneumatischer Förderung in einem System (6*)
• – Verkleinerung des Einspeisebehälters (9).

An effort reduction based on the invention is given by:

• - omission of the intermediate bunker ( 7 . 1 )
• - Reduction of the height of the feed system
• - Integration of sluice and pneumatic conveying in one system ( 6 * )
• - Reduction of the feed container ( 9 ).

LIST OF REFERENCE NUMBERS

1

Rohkohlefördertechnik

2

Rohkohlesilo

3

desiccation and grinding the coal (combined or separately)

4

dust filter

5

Kohlestaubsilo

6

pneumatic conveyor system

7

intermediate bunker

8th

lock system

9

feed tank

10

coal gasification

6 *

lock system with integrated pneumatic conveying or dust pump

Claims (7)

Apparatus for fuel mill drying and fuel feed for an entrainment gasification plant ( 10 ), in which a combustible dust is gasified at a pressure of between 0.1 and 1 MPa to a crude gas rich in H and CO, comprising - a device ( 3 ) for grinding and drying of the raw fuel to combustible dust, - a downstream dust filter ( 4 ), - a dust filter downstream of the fuel dust silo ( 5 ), - a lock immediately downstream of the fuel dust silo ( 6 * ) with promotion to the pressure of the entrained flow gasification plant, - a feeder tank downstream of the lock ( 9 ) and - the entrainment tank downstream entrained flow gasification plant ( 10 ). Device according to claim 1, characterized that the lock by a lock system formed with several locks given is. Device according to one of the preceding claims characterized characterized in that the lock a pneumatic conveying having. Device according to Claims 1 to 2, characterized the lock has a dust pump for delivery. Device according to one of the preceding claims, characterized in that the exhaust gases from the lock ( 6 * ) the filter ( 4 ) can be supplied. Device according to one of the preceding claims, characterized in that the exhaust gases from the feed tank ( 9 ) the filter ( 4 ) can be supplied. Device according to one of the preceding claims 5 to 6, characterized in that the exhaust gases to avoid a dew point can be preheated.

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