DD147249A1 - METHOD FOR LOADING A CARBON PRESSURE GAS REACTOR - Google Patents

Abstract

The invention relates to a method for feeding a pressurized reactor with a piece of material by means of a periodically operating lock. The aim of the invention is to avoid the caused by covering the lock with raw gas pressure fluctuations in the reactor to prevent the condensation of water and Teerdaempfen in the lock, and to reduce the Verschleisz of piping and fittings. This is done by stringing the lock in two stages. The covering of the lock takes place in the 1st stage with raw gas from the Rohgassammelleitung with a temperature of 20 to 40 degrees C. In the 2nd stage, the remaining covering with raw gas after Vorkuehlung with a temperature of 180 to 200 degrees C or with a other medium which is available under appropriate pressure.

Description

1 70 3

Title of the invention

Method for charging a coal-pressure gasification reactor

Field of application of the invention

 The field of application of the invention is the known process for the pressure gasification of coal in a fixed bed. This process operates at a reactor pressure of 2 to 5 MPa. The coal enters the reactor in lumpy form through a lock upstream of the reactor. This lock is depressurized to atmospheric pressure and then re-pressurized to reactor pressure. The invention relates to such a method for feeding the reactor with coal.

Characteristic of the known technical solutions

Known technical solutions differ primarily in the nature of the gas, which is used for covering the lock. In pressure gasification plants, a portion of the gas generated in the reactor is usually used for covering the lock. The Rohga3 is hereby removed directly from the upper part of the reactor or, as in DD-WP 110 299, after the downstream pre-purification stage. This method has the following disadvantages:

- The discontinuous removal of relatively large amounts of gas leads to pressure fluctuations in the reactor and

thus disturbances of the gasification process.

- In reactors equipped with water jackets and pressure equalization from the water jacket to the reactor interior, these pressure fluctuations cause fluctuations in the aaer production of jacket steam. The generated jacket vapor vsird. usually immediately fed back to the process as gasification steam. Fluctuations in the production of jacket steam therefore lead to disturbances in the gasification process.

- The raw gas, which from the reactor, or after the

downstream washing cooler or waste heat boiler ent. is still has a temperature of 180 to 600 ⁰ C. In the lock, the gas cools down, and it comes to the condensation of water and Teerdämpfen. These condensates promote the formation of pesticide bridges in the lock and hinder the feed of the reactor.

- The raw gas has a high pesticide content immediately after the reactor. The fittings in the pipes, which are required for covering the lock, are thereby subject to high wear.

Hach another method, is used to cover the lock recompressed raw gas. This method has the disadvantage that additional compressor capacity is required for the compression of the raw gas. ^;

According to a further known method, which is described in DE-OS 2607 754, the closing of the lock with an inert gas, such as nitrogen or carbon dioxide. This method also has the disadvantage that additional compressor capacity is required for compressing the inert gas.

Object of the invention

The aim of the invention is to develop a method for feeding a coal-pressure gasification reactor which excludes the disadvantages of the known technical solutions.

Explanation of the essence of the invention

The object of the invention is to find a way to. to secure the covering of the lock, without pressure fluctuations in the reactor and thus disturbances in the gasification process occur. The temperature of the gas used to cover the lock should be lower than the temperature in the lock and further the gas should be free of water and tar fumes. The provision of the gas used for covering the lock should be made without additional compressor capacity. The gas should continue to be free of pesticide particles. The technical reason for the pressure fluctuations in the reactor caused by the covering of the lock is the removal of the gas used for covering the lock directly from the reactor itself, or from a downstream apparatus directly assigned to the individual reactor. This gas still has a temperature of 180 ⁰ C to 600 ⁰ C and therefore causes the aforementioned condensation phenomena in the lock. The gas withdrawn directly from the reactor still has a large proportion of pesticides, which leads to excessive wear of the fittings in the piping systems required for the covering. When using this gas, however, an additional compression is not necessary and the lock can be directly covered to the pressure level of the reactor.

If the raw gas after the cooling stage with a temperature of 20 ⁰ C to 40 ⁰ C used for stringing the lock, it is always a liachverdichtung required because the pressure drop from the reactor to the end of the cooling stage is too large.

If an inert gas, nitrogen or carbon dioxide is used to cover the lock, it is necessary to compress this gas to the pressure level of the reactor in each pass.

According to the invention, the covering of the lock takes place in two successive stages. During the first stage v? Ird the lock with crude gas, which, drawn by the cooling stage from the temperature-Rohgassammelleitung with a 'temperature is withdrawn from 20 to 40 ⁰ C.

Since the gas used for stringing the lock is removed according to the invention from the raw gas manifold after the cooling stage, occur through the covering no pressure fluctuations in the reactor interior. The Temperatur of the raw gas from 20 to 40 ⁰ C excludes any condensation phenomena in the coal lock. After the cooling stage, the raw gas is largely free from contamination. Wear and tear in the pipe system required for covering the lock as well as on the fittings are therefore excluded. Due to the, caused by the apparatus of the cooling stage pressure loss, the crude gas after the cooling stage has a pressure which is about 0.05 to 0.5 MPa below the reactor pressure.

A stringing of the lock up to the level of the reactor pressure is therefore not possible with this gas. The rest of the sluice therefore takes place in a second stage with another stringing gas. .

Pure the rest of the cover can again raw gas after the pre-cleaning stage with a temperature of about 180 to 200 ⁰ C.

be removed. Due to the small difference in pressure and the only small amounts required for the residual covering the mentioned negative properties of this gas removal, such as high moisture content, Kondensationsse.rscheinungen, contamination * and pressure fluctuations are negligible. The residual covering can also be carried out with another gas which is available at a sufficiently high pressure level. Such gases can, for. As nitrogen, carbon dioxide, methane or natural gas.

embodiment

The invention will be explained below using an exemplary embodiment

 A coal pressure gasification plant consists of several reactors 1 with downstream washing coolers 2, waste heat boilers 3 and condensing units 4, which are flowed through by the gas generated in the reactor 1 in succession. After the condensation plants 4, the purified and cooled crude gas of all reactors 1 is fed into the common raw gas manifold 5. The coal used for the gasification passes from the storage bunker 6 via the lock 7 into the reactor. Since the process operates at a reactor pressure of about 2.5 MPa, the lock 7 must be filled in the pressureless state with coal from the bunker 6. Subsequently, it is covered to 'the pressure level of the reactor 1. Subsequently, the coal passes from the lock 7 in the reactor 1. This entire process is cyclical. According to the invention, the covering of the lock 7 takes place in two stages.

In the 1st stage, the sluice 7 is covered with cooled, purified raw gas from the raw gas collecting line 5 via fitting 8. The pressure in the collecting line 5 is approximately 0.05 to 0.5 MPa below the pressure in the reactor 1. BifeS " The lock 7 can. Accordingly, only up to this pressure

be covered. Now the valve 8 is closed · The rest of the sluice 7 takes place via the valve 9 with raw gas, which is removed after the waste heat boiler 3. "This gas has approximately reactor pressure.

1βΟ Contaminants still present in the raw gas at this sampling point. Water and Teerdämpfe are negligible due to the small amount of residual gas used

 Pur the rest of the sluice 7 can be used instead of raw gas and another gas which is at least at reactor pressure. Such gases may be, for example, nitrogen, carbon dioxide or natural gas. If the pressure in the lock 7 has reached the level of the pressure in the reactor 1, the valve 9 is closed again. The coal can then be conveyed from the lock into the reactor.

Claims (3)

invention claim ; · · ':' '' 1. A method for feeding a Kohledruckvergasungsreaktore, characterized in that daa covering the lock is carried out in two stages, wherein the stringing in a first stage with loosened and purified raw gas from the Rohgassammelleitung and the remaining cover in a second stage with ei-.nem other suitable gas is made. 2. The method according to item 1, characterized in that · for the covering in the second stage raw gas after the pre-cooling stage, which has a sufficiently high pressure level, is removed. 3. The method according to item 1, characterized in that for the covering in the second stage another with sufficient high pressure level available gas can be used. For this 1 side drawings