DE630160C - Process for the production of a high-quality industrial and town gas in continuously operated, externally heated chambers with gas purging in direct current with the fuel - Google Patents

Description

Process for the production of a high quality industrial and city gas in continuously operated, externally heated chambers with gas purging in cocurrent the fuel In the field of the production of industrial and town gas from fuels of all kinds, especially from bituminous fuels, are numerous processes have been developed which also make use of the use of purge gases. He follows now the purging in countercurrent to the downward sinking fuel, so come out of the externally heated degassing shaft and from the upper layers (the fuel column the degassing and smoldering products with large amounts of water vapor in practically urized decomposition State out, and when processing bituminous fuels, e.g. B. lignite briquettes, the carbonic acid content of the gas produced rises to 2 "½" and above.

Such a gas could not be used for town gas purposes without using a subsequent carbonic acid wash in order to reduce the carbonic acid content to at least ro%. Furthermore, since the water vapor content of the production gas produced is very high, it is never possible to achieve subsequent splitting of the tar in downstream crevices without prior separation of entrained tar vapors and re-evaporation of the tar To be carried out in the presence of the large amount of water vapor in hot, unfilled spaces provided above the degassing chamber. But in this case too, the carbon dioxide content remaining in the production gas would be well over ro % .

In order to reduce the carbonic acid content, therefore, other methods have been used formed in which the externally heated fuel in cocurrent with the downwardly migrating coal is treated by purge gases. In these cases, provided that the purge gases are present in sufficiently large quantities, the with your gas downwardly led tar vapor in the approximately 80o ° hot cracking zones split up. A partial reduction in carbon dioxide in the same cracking zone is also a pressure reduces the carbonic acid content in the production gas. As already indicated, but must Purge gassing must be carried out with ample amounts of purge gas, otherwise tar build-up, Tar coking and the resulting sticking of the fuel column on the Walls can occur.

When working on town gas with a calorific value of around 4000 kcal the sufficient amount of water gas purging gas can only be added if its calorific value is more than z8oo kcal. Normally operated water gas generators in two-way circuit (Bubbles and gases) work, a gas of generate z8oo kcal / ms; usually the Calorific value r -um -260o keal . lie around, as there are always considerable amounts of nitrogen in the water gas .will.

Water gas produced in externally heated chambers, however, results a stick °, low-carbon gas in addition to lower amounts of carbonic acid, if the temperature the chamber is high enough. But here, too, the calorific value is not constantly increasing Can keep 280o kcal, because the temperature in the heating flues is not kept that high allowed to increase the temperatures inside the gasification chamber and in the gasification coke To bring 90o to iooo °. Such a heated gasification chamber would be in short Time to induce melt flows in the heating flues. Mostly the temperature is in the core the amount of coke to be gasified is only 80o to 90o °, so that here only a gas with around 270o kcal can be generated in continuous operation.

Furthermore, these known methods require in which the degassing chamber separated from the downstream or adjacent coke gasification apparatus is arranged, a so-called Koksaustragsschleuse, whereby in addition to partial attrition of the coke that accumulates in lumps always with a required amount prior to discharge Reduction in temperature of the coke must be expected. However, this causes heat losses that could otherwise benefit the entire process.

The automatic coke discharge lock is already known by a Avoid process that "lets the degassing shaft immerse in a molten salt, which is heated to about iooo °, so that either the resulting coke in a direct Treated gas chamber located under the degassing chamber with water vapor is or the stepping after the lower chamber space filled with molten salt Coke automatically after the one next to it, which is also filled with molten salt Carburetor chambers, in which it is due to its low specific weight rises automatically through the hot melt.

In this case, the gasifier rooms located next to the degassing area are used blown in superheated steam. The water gas generated here was, however, at this known method passed into the lower degassing chamber space, so that the water gas used as purge gas in countercurrent to the downwardly sinking fuel quantities, So flowing upwards, the fuel column flows through. Because in this way purge gas and production gas together with the resulting tar and water vapors in ascending order Currents can be fed to colder zones, as already stated .wurde. no significant tar breakdown and: X. carbonic acid reduction in the fuel column ':take place. You therefore have to add the acidified gas-steam mixture that was described above escapes from the fuel layer, send it through the glowing zones downstream or feed the tar vapors back to a cracking plant after they have condensed, if they are to be used in the gas produced.

It has now been shown that in the previously mentioned method can avoid existing disadvantages if the water gas from the molten salt and the high-quality water gas as a flushing agent, in the same direction as the downwards Migratory fuel is used.

Compared to the known method in which the water gas either continuously in externally heated chambers or in normally operated water gas generators is produced, has the water gas generated in the known ° manner in the molten salt a much higher calorific value (3ooo kcal), since the molten salt has a temperature of owns about i 100 °. As a result, the degassing according to the present Carry out the invention with far larger amounts of purge gas than when using conventional Water gas with 2.60o to 270o kcal calorific value without having to worry about the calorific value of the city gas drops below 400o kcal.

Furthermore, the temperature of the coke in the degassing shaft (at the level of the cracking zone) increases when it enters the table salt melt zone below it, within the lower part of the chamber and continues to increase when it crosses to the water gas generation chamber, which was intentionally heated to a higher temperature (about i1000).

The advantages of the new combination process compared to the previous ones The methods that have become known are therefore as follows: The water gas generation takes place at a high reaction temperature (about iioo °), without the water gas obtained through Proportions of flue gases is contaminated; therefore, the obtained water gas has a Calorific value of over 280o kcal and only contains very small amounts of undecomposed water vapor, Carbonic acid and nitrogen with it.

This composition of the water gas serving as the flushing gas therefore leaves the generation of a gas derived from bituminous fuels using Far greater amounts of purging gas than is possible with the usual water gas purging process in which the carbonic acid and nitrogen content are also mixed in Smoke gases are large and ultimately also the amount of water vapor carried along as a result insufficient steam decomposition is far greater. These advantages cannot be found in any known Concurrent purging process achieved with respect to the generation of the water gas purging agent will.

On the accompanying drawings is one for performing the procedure suitable system shown for example.

Fig. I shows a schematic of a degassing system for lignite briquettes.

Fig. 2 shows a vertical partial section through the water gas generator.

Fig.3 shows a horizontal section through the water gas generator on a reduced scale.

The bituminous fuel emerges from the storage bunker i after passing through it the automatic or manually moved entry sluice 2 after the intermediate bunker 3, from where the coals are released according to the consumption of the coke in the production of water gas slide off automatically after the degassing chamber 4. This is due to the heating flues 5 heated. At 6 is the amount of fuel in the uppermost part of the chamber Purge gas supplied. In the shaft part 7 is due to the downwardly directed purge gases the drying, smoldering and degassing supported advantageously. In the temperature zone 8, in which about 8oo °. Is reached, finds the required tar vapor splitting and a partial carbonic acid reduction takes place, with one according to Fig. i at 9 the outlet of the gas mixture io can arbitrarily change so that the Move cleavage zone 8 upwards according to the drawn line 8a leaves.

Below the gas outlet 9, the chamber part i i is used for post-degassing of the coke, to about the temperature iooo ° within the molten salt bath in the lowest Chamber part is reached, which is immersed in the melt 12. As a result, it rests the completely degassed coke produced in the degassing chamber partly on the Bottom of the melt pool or the melt pool trough, on the other hand part of the Coke according to the amount consumed in the gasifier cell 13 by the here molten salt brought to about 100 ° because of the significantly lower specific Weight of the coke compared to that of the melt automatically according to its surface.

In this gasification chamber, the floating on the melt, z. Sometimes submerged coke is completely gasified by the superheated water vapor that has been introduced into the melt, which takes on the temperature of the molten salt the lines 14 and 15 are fed to the degassing chamber at 6. Excess water gas can, however, be passed through the lines 14 and 16 to the water gas collector 17. The supply line i8 enables a water gas supply. to the gap chamber i9 serving as a carburator, from which a water-gas gap gas mixture is fed through the lines 2o and 15 for the purpose of purging the chamber 4 to the upper chamber part e. With the appropriate settings of the taps 35, 36, 37, 38, 39, 40, 41 to 45, it is possible to send either the entire amount of water gas or only part of the water gas to the gap, while the remainder is sent through the lines 15, 16 and 22 is supplied to its various destinations.

In addition, excess water gas can be collected and also ever If required, water gas to flush the upper chamber part 7 and the lower chamber part. i i can be used, and that would be free of cracking gas through lines 15 and 22 Water gas can be supplied. The purge gas passed through line 22 enters 24 into the chamber zone ii.

By setting the valve taps shown in Fig. 1 accordingly but it is also possible - in the gas collector 26, in the chambers at 6 and 24 and furthermore, unmixed cracked gas through line 2i in the finished production gas to send or even mixtures of cracked gas and water gas in any necessary or desired composition.

The method thus allows the upper and lower chambers to be flushed with purer water gas, with mixtures of water gas and cracked gas or with pure gas Carry out cracked gas, also pure water gas, pure cracked gas or mixtures thereof after the collection container and from there to other consumption points conduct.

In addition, the method provides the possibility of tar cracking or carburizing within the gas space of the molten salt or in the water gas generator. In Fig. 2 and 3, the position of the water gas generator next to the degassing shaft and the heating rooms for the molten salt can be seen, as well as the steam supply to the molten bath of the gasification chambers. The degassing shaft ii placed in the middle in this example shows the two gasification chambers 13 with the steam superheater chambers 30 and the steam supply lines 31 as well as the two longitudinal heating chambers 28 with the flue gas ducts 2g on the right and left. The molten salt quantities contained in all the chambers, which are heated from the chambers 28, are connected to one another through the common melting tank. The immersion depth of the partition walls or the connecting paths between the chambers are designed so that the individual gas spaces are separated from one another, although the coke emerging from the degassing chamber ii can automatically pass to the gasification chambers 13.

-The splitting of the substances used for carburizing can be done in the gas chamber the gasifier or the molten salt take place. Here, however, one must prevent that the product in the gas space overheats by staying too long and too largely is dismantled. For this reason, i i introduced a dip tube 32, which from the outside through the above the molten salt 12 in the chambers 13 stored hot water gas is heated. Inside the immersion tube 32 is arranged vertically movable a second tube 33, through which the for Cracking used carburizing agents introduced under pressure or with the addition of steam depending on the carburizing agent used and the desired Degree of decomposition the middle movable tube 33 to the necessary distance of the surface of the melt standing in the pipe 32 is adjusted.

The carburizing agent is introduced through the nozzle 3q., and the cracked gas generated emerges from that located between the tubes 32 and 33 Annular space at 32 'to be derived from here -from to the individual points of use to become.

Just like with the well-known degassing and smoldering processes below The molten salt is also used in the concurrent flushing process for the processed Ent- and gasification material avoided an automatically and mechanically moved discharge sluice. The temperature of the material fed from the intermediate bunker to the degassing shaft increases from the outside temperature on its way up to the complete gasification up to the gasification taking place at iioo ° steadily increases, with the entire fuel in usable gas is converted. It goes without saying that those in the products and amounts of heat present in the exhaust gases for, for example, outside the Degassing chamber laid gap or. Carburizing process and for steam generation are largely exploited.

Claims (3)

PATENT CLAIMS: i. Process for the production of a high quality industrial and town gas from bituminous fuels in continuously operated, externally heated Chambers below aligned with the downward moving column of fuel Gas flushing by means of high quality water gas, characterized in that the water gas from the coke of the degassing zone in one of these below, to about 100 ° heated molten salt bath into which the gasification chambers extend. 2. The method according to claim i, characterized in that the calorific value of the water gas increased by admixing a cracked gas generated outside the degassing shaft will. 3. The method according to claim i, characterized in that the carburization of the water gas is made by fission gases within the gas space of the molten salt will.