DD145180A3 - METHOD FOR THE PRINTING AND GASIFICATION OF RAW BROWN COAL - Google Patents

Description

 -4-

a) Title of the invention:

Process for pressure deaeration and gasification of crude lignite

b) Field of application of the invention?

The invention relates to a process for Druckent- and gasification of raw lignite, especially lignite, in which the drying of the coal is coupled directly with the Druckent- and gasification process and the energy required for the drying process is minimized. The drying proceeds very gently, so that the direct use of granular lignite coal with a high water content, in particular lignite coal, can take place without a disintegration and degassing affecting grain disintegration

 By applying the method according to the invention, it is possible to gasify grained lignite with a low degree of coalification in the plague bed or in the fluidized bed under pressure, if necessary to produce a granular low-smoke fuel.

c) Characteristic of the known technical solutions

It is already known to use lignite, in particular Y / eich brown coal _s for pressure gasification in a plague bed or in a fluidized bed. This comes in the Pestbettdruckvergasung in Porm of briquettes

it is used in the Pest bed pressure gasification in Perm of briquettes, an elaborate preparation of the same about the Peinkornaufbereitung, drying and compression is necessary in the previously known solutions. At high specific performances of the pressure gasification process, the briquette does not cope with the strong thermal loads and decomposes during the afterdrying and degassing in the gasification reactor, combined with a very high dust discharge by the gasification raw gas. "Furthermore, grains of lignite were used in the pressure gasification process outside of the Gasification plant in tube dryers had been dried.

The pressure gasification process with high specific power and without increased dust discharge has so far been mastered only with use of dry grains of hard lignite and with the use of hard coal. "In dried in tube dryers grains of lignite on the other hand, sustainable dust emissions could be realized with the raw gas only at low specific gasification services. To increase the gasification capacity, lignite is currently used predominantly in the form of briquettes in the Pestbettdruckvergasung. In the briquetting and drying systems a high expenditure on technical equipment, & n operating and maintenance effort is required "Environmental pollution by dust is considerable."

As a result of the dry coal dust forming, the plants are always at high risk of explosion. In the promotion of dry fuels occurs considerable wear. Furthermore, the energy required for drying by the evaporation drying and the associated waste heat losses is high · »

Several proposals have already become known in the past which are intended to eliminate or reduce the disadvantages associated with the use of lignite. So was proposed in DD-PS 26 392, the gasification before and / or in the pressure carburetor so much with

Sprinkle gas water that the gas outlet temperature is lowered from the fuel bed.

In DD-PS 38 791 a method is described in which only a portion of the hot gasification material used for the degassing and drying of the fuel and the residual gas is withdrawn separately.

Similar proposals, which have been described above, also brings the DD-PS 119 814th

 In DD-PS C 10 J / 205 413 it is proposed to control the amount of crude gas for post-drying and degassing so that a predetermined heating rate occurs in certain temperature ranges and a very gentle pre-drying is performed

The patents DD-PS 121 796 and 120 043 recommend to increase the water content of the fuel used, in briquettes to 20 - 24 % and in dry charcoal cartilage up to 45 % ·

The listed proposals have not yet been introduced in practice. Although the decomposition of the fuel in the pressure gasification reactor can be more or less restricted with its implementation, additional process engineering parts and additional loads are associated with it at the same time

 These known proposals are based on the use of briquettes or convection-dried carbon grains, with the lack of inadequate resistance to pressure gassing inherent in them. They also do not change the fact that the production of briquettes and dry grains requires a high level of plant, energy and operating costs. "For example, for the evaporation of water from coal alone, a heat quantity of 3,100-3,300 kJ is achieved / kg of evaporated water needed. , '

Hard lignite is difficult to briquet. On the basis of this knowledge, it was already

50 years a process for drying the hard lignite

This was first described in German Pat. No. 466,617 and known to the inventor as a Flexpress or pressure damping method. In this case, the coal is heated under pressure with saturated steam, whereby the water can not evaporate. Due to the onset of heating of the coal shrinkage and the split off CO ₂ , a portion of the water is expelled in liquid form.

This results in a reduced energy requirement for the deposition of V / assers and a largely uniform heating and shrinkage of the grain, since the separated water does not extract as the evaporation drying the carbon grain constantly the transmitted heat, After the original method described a number of proposals was made who wanted to shape and develop the same. " For example, in the 'Patents DR-PS 520 369, here is used instead of steam hot water as a damping agent, DR-PS 527 021, here, the steam is used superheated, DR-PS 583 907, DE-PS 1049 and 1189 465, OE-PS 185 349, 190 490 and 244 u »a. The main objective of the procedure is to improve the heat economy. " With the inventions underlying DE patent specifications 1201 254 and 1243 109, the aim is to make the process continuous. The procedural expenses for this, however, are very high, so far could not prevail in practice, a continuous process. ·

The advantage of the method of pressure damping of coal lies in the low energy requirement of 1 400 - 1 700 kJ / kg of separated water and in the gentle drying of the coal. "Compared to the convection drying, the wax portion is noted that for drying higher tensioned steam required is. During the relaxation of the pressure-damped coal, part of the water is evaporated at low pressures and in the unpressurized state. This process inevitably leads to a deterioration in

and damage to the coal grain, albeit to a much lesser extent than convection drying. After relaxation, a reabsorption of water by the coal is possible to a small extent. The pressure damping method has hitherto been put into practice when using hard lignite and highly lignitic lignite. Already strongly lignitic brown coal was also conveyed to a pressure gasification plant and gasified in a fixed bed, which had previously been dried in a pressure-reducing plant with steam.

Concerning the pressure damping of mulmiger, brikettierbarer soft lignite the concerns exist that the sludge attack is too high. Although attempts have been made to attenuate such lignite coal, but only with the aim of using the dried coal for briquetting or as a fuel in furnaces «It turns out that a dehydration of the coal under 30 % is only possible with increased effort and the briquetting of the coal is usually worsened by the pressure damping. The increased water content after drying limits the economic transport distance compared to the briquette. For the rational use of waste heat, the pressure damping method requires several pressure vessels coupled together and many connecting pipelines. The dewatered coal must be recovered after damping.

161; be cooled. Due to the discontinuous operation, the technical expenses continue to increase. Thus, materially complex equipment is required for this method, and the operation cost is high. Due to the forming dust, the environment is polluted and the x) caused by coal dust explosions. x) danger

, d) Object of the invention *.

The aim of the invention is therefore to combine the drying of the raw lignite coal directly with the pressure deaeration and gasification process and thus to achieve an extremely gentle drying of the coal, in particular in all soft lignite coals.

The object of the invention is also to reduce the thermal energy requirements5 the plant-technical expenses and the operating effort *

e) Presentation of the essence of the invention:

The invention is based on the object of realizing the object of the invention while avoiding the drawbacks explained above has been particularly disadvantageous in the pressure gasification of lignite, especially lignite coal, as already described, the high dust accumulation in Druckvergasungsrohgas proven · Recent investigations justify the disintegration of the briquette as follows: The briquette is held together by binding forces, triggered by the water contained in the dry coal, the residual binder forces only a loose and very abrasion-sensitive briquetting gasification briquettes, which are known to be pressed from coarse-grained dry coal, decay at high thermal stress particularly light the briquettes are further provided with a temperature of about 303 _e - brought into the gasification reactor 313 K, .from where temperatures 523 - 773 K prevail. This thermal shock leads to uneven heating of the briquettes · The outer briquette layers dry faster, consequently they shrink more and decay-accelerating stresses develop. »Also, the dry-coal grains in the briquette have different water contents, the higher the average water content is Drying of the briquettes in the gasification reactor thus distinctively shrinks these grains, which also leads to a strong loosening of the briquette structure. "The decay of the dry coal grains, in particular that of lignite, is justified as follows? Drying of the grains from lignite is carried out by convection drying, usually in tube dryers,

by evaporation of dea water * This evaporation begins at the outer layers of the grain and begins in the nucleus only greatly delayed. The result is a water content difference in the finished dried grain between shell and core of more than 30 %. As a result of the resulting strong shrinkage of the outer shell compared to the core, the outer shell loosens and is very sensitive to abrasion. The high volume of steam forming during the drying process is prevented by the coal of the grain at the outlet and forcibly seeks a free path by means of the expansion force, whereby the grain is partially destroyed. These grains cool on the way to the generator plant on cac 3P3 - 313 K. from. The carbon grains dried by convection drying must even be cooled in order to avoid self-ignition of the coal. These cold carbon grains are currently exposed to temperatures of 523 - 773 K in the generator. To the interior of the grains, the boiling temperature of the water has reached, abruptly sets of the grain shell beginning to the core a strong shrinking of a which leads to further destruction of the already j_ _n (j _he weakened upstream coal drying plant grains

These phenomena occur when using hard coal and hard lignite in the pressure gasification, due to the already caused by the nature of the shrinkage (coalification) of these coals and the associated low water content not or only to a small extent. It has not yet been recognized that the direct procedural coupling of the pressure damping with the pressure gasification is one of the most harmonious connections in the process technology of coal refinement and this allows _} the known technical solutions adhering to the above defect largely eliminated.

According to the invention the object is achieved in that for the Druckent "and gasification certain granular

Crude lignite, in particular white lignite, with a lignite

9 3

Water content of 55-60 % from a bunker in a known manner by means of a coal lock on pressure and then placed in a damping chamber, the same pressure as possible as the degassing and gasification chamber or,

> 1 MPa, but preferably> 2 MPa. In the tap area, the raw lignite is dewatered and pressure-calcined with a damping agent, preferably with saturated steam. The thus pre-dried hot coal is now «more preferably without pressure release, but in no case with a relaxation to a pressure <1 MPa and preferably without cooling, but in no case with a cooling to a temperature 423 K, introduced into the degassing and gasification. Due to the high heat content, which is pre-dewatered by the pressure damping coal. These are further gently dried in the degassing and gasification chamber and then fed to the degassing and gasification.

It has been shown that the pressure damping of V / eichbraun coal little fines incurred, but only a part of the large. Grains in middle grains decomposes. However, such Zerfallsersclieinung affects the process of Pressure- .und gasification hardly adversely _s since the dehydrated. Grains have a relatively high abrasion resistance. The water dripping from the coal during pressure damping cleans the coal from ultrafine particles and is usually continuously separated in the pressure damping chamber. This cleaning effect can be enhanced by atomizing recycled hot steaming water in the steaming room above the bed of coal. "The continuous demand for fuel in the ent-gasification room also permits the continuous transfer of the pre-dried coal into it. The steam used for pressure damping is saturated at the chosen process pressure and introduced into the pressure damping chamber above the coal bed in such an amount that always a small amount of residual steam is removed together with the gases which are entrained during the carbonization of the coal into the exhaust gas. and gasification room flows «

The water vapor can also be introduced slightly overheated in the gasification chamber. It could be stated that crude lignite, in particular lignite, precipitates the bulk of the water already at the beginning of the damping and it. it is not necessary to carry out the pressure damping until the residual water flow is released at the pressure in question. "The pre-dewatered and heat-soaked coal will withstand the subsequent stresses of after-drying and heating in the removal and drying process. Gasification room without major damage. It is essential that the raw lignite in the pressure damping to approximately the or a higher temperature, which occurs at the prevailing process conditions as the boiling temperature, but at least 423 K, evenly heated and the shrinkage process is uniform but largely completed before the coal into the degassing and gasification room * Even if the coal still has a higher 'water content of z. B. has 35 - 40 % , this is "without significant drawback · The resulting water vapor has only a small fraction of the volume at atmospheric pressure in the final drying in Enttmd Vergasungsrautn and can flow through the coal without their Gefügelockerung," Also takes place at a grain temperature, the between 423 K and the boiling temperature corresponding to the selected process pressure, the transport of the core from the core to the shell of the grain as a port setting of the damping process is predominantly in liquid form since the pre-dried coal passes without cooling and contact with air into the degassing and gasification space The surface of the grain is not oxidized and hardened, but remains plastic, which does not hinder the escape of steam during the after-drying process.Reabsorption of water can not occur.The heat carried by the pressure-damped hot coal into the degassing and gasification chamber is, for example, sufficient to the coal of 35 - 40 % Wasserge to post-dry to the usual water content of 20 % when using briquettes, ie. without additionally extracting heat from the degassing and gasification room * These effects, the

have hitherto not been observed, cause the gentle Hachtrocknung the pre-treated by pressure damping coal in Ent- and Vergasungoraum. The incomplete dewatering of the coal at the pressure damping allows the shortening of the damping time and thus at the same time the reduction of the damping chamber · It was further found that the dehydrated carbon grains survive the Druckentgasung with a low decay compared to the briquette and the coke formed a higher Abrasion resistance "With this, however, it is possible to guide the pressure-dewatered carbon particles largely safely through the pressure degassing zone into the gasification zone.

The damping water produced during the pressure damping is released and the steam produced at atmospheric pressure and optionally the hot water are used to preheat the raw coal to approximately 373 K. The dampening water can also be used for hot water production. It is also possible to use the expanded hot water to hydraulically convey the raw coal to the bunker and the pressurized dampening water to convey the raw lignite from the coal sluice to the damping vessel upstream of the deaerating and gasification reactor. In the latter case already takes place evaporation by the hot water. In order to be able to keep the damping chamber small, it is expedient to prepare the raw lignite in the coal lock by means of a partial flow of the damping agent and / or hot damping water.

When pre-drying the raw lignite coal according to the method of the invention is the heat demand when using the damping mass for heating the raw coal at 363 K only 1 000 - 1 200 kJ / kg deposited at the pressure damping Y / asser and is thus lower than at sepa. Rate pressure damping systems * The advantage derives from the fact that the hot coal after damping is no longer

36O waste heat losses, but this coal

208465 · "ii

heat in the degassing and gasification process or »is fully utilized in the subsequent Abhitzeverwertungsprozeß. Due to the possible continuous operation of the damping process eliminates heat losses by cooling the damping vessel and the discontinuous steam relaxation.

The process-related additional expense is low due to the "integration with the pressure degassing and gasification process." The method according to the invention makes it possible to combine the pressure damping process and the degassing and gasification process in a correspondingly large pressure vessel. Separation of steam into the degassing and gasification process does not require separate addition of steam to the degassing and gasification plant, since it is usually not necessary to use additional steam feed to the gasification and degassing plant because the gasification steam feed can be used In order to protect the outer pressure-bearing outer skin, gas and water vapor usually have a water jacket. The water vapor generated in this water jacket can be used very advantageously for pressure damping in the described method.

Bas inventive method. Claims no additional operating forces «

The hitherto usual, already described high expenditure for.

the separate dry coal production can be omitted. Since a coal dust discharge into the environment is not possible, the process is extremely environmentally friendly. Coal dust explosions can not arise.

Me concerns of increased sludge economy in pressure. Damping of soft lignite is wrong »If you compare the briquette used in the pressure decanting and gasification, so there occur 3 % losses in the briquetting and 10 - 15 % losses due to dust in the pressure gasification process, which predominantly as

The sludge content in the process according to the invention is highly dependent on the design of the individual process steps, but does not exceed that which can be observed in briquette use.

The process according to the invention also permits the use of strongly ash-free coals which otherwise can not be used when the briquetting stage is interposed as a result of the high degree of wear occurring in the pressure-damping process. Part of the ash, particularly finely divided particles, is mixed with the damping agent segregated ·

Compared with the usual use of briquettes for pressure deaeration and gasification, the raw lignite treated by the process according to the invention has a better rolling action. It thus improves the bulk material movement in the generator and avoids the formation of bridges and channels which increase the gasification process Dust discharge and an uneconomical generator operation lead.

The combination of the pressure damping with the pressure deaeration and gasification can be solved in such a way that the puncture of the coal slush and pressure damping of a vessel, as it were by an enlarged coal sluice «. The pressure damping process is carried out discontinuously just like the Kohleschleuseung. According to the invention, the Ent- and gasification reactor associated with several vessels for Eohleschleusung and pressure damping, which supply the ent and gasification reactor alternately with hot pre-dewatered coal.

In this process variant, the disadvantage of the discontinuity and the increased heat energy requirement is equalized by the need not be paid to a uniform bulk material movement in the damping chamber, the damping water separation is easy and the pressure damping with a higher, if necessary

"^ 13

low pressure than in Druckent- and gasification chamber prevails, can be performed. "

If a very dry fuel for the pressure deaeration and gasification process is desired, it is possible to follow after the sub-step of the pressure damping with saturated steam drying with superheated steam · To speed the dewatering process can also work in this variant during the damping process with a higher residual steam · The result is a higher flow velocity of the steam in the coal bed and thus a better heat transfer to the coal * The residual steam amount with the derived COo is used as well as the steam discharged at a pressure damping following drying with superheated steam as a gasifying agent · It is also so far has not yet been recognized that the hot, high water vapor-containing raw gas leaving the Druckent- and gasification process can be used very advantageously as a pressure damping means · The raw gas of the Pestbettdruckvergasung has at the outlet of the reactor after his Saturation a very high water vapor partial pressure, which is several times higher than the partial pressure of the gas when using lignite. Therefore, even after saturation with water vapor and after the cleaning of dust and condensed hydrocarbons, the crude gas still has the required high temperature for carrying out the damping process.

The use of raw gas ink pressure deaeration and gasification process further simplifies the grain-46C combined pressure damping, pressure deaeration and gasification process. The raw lignite, in particular lignite, is placed in a pressure vessel in which the pressure damping · as well as the degassing and gasification process takes place. The raw gas produced in the lowest part of the vessel by partial combustion of coal in a fixed bed flows countercurrently.

to the coal upwards and leads in the building up various zones through the degassing, drying and pressure damping and exits in the upper part of the pressure vessel from this ", The dripping in the pressure damping from the lignite coal saturates the emerging from the post-drying zone raw gas" The of the However, raw lignite, especially when using Y / eich brown coal in the pressure damping emitted amount of water is generally much larger than the amount of water required for saturation of the raw gas. »Depending on the chosen process parameters, a part of this excess water in ITebelform out of the pressure vessel with the raw gas» The remainder passes into the habitat drying and de-gassing zone, where it is evaporated when heat is removed. The latter leads to increased gasification agent and fuel requirements. This can be prevented by adding devices to the water between the pressure-damping zone and the drying zone The separation of damping water recirculated in the circuit in the upper part of the pressure vessel makes possible an increased cleaning of the dust accumulated during the damping process as well as with the raw gas. · The hydrocarbons condensed during the cooling of the raw gas during the damping process improve the bulk material content egung in the damping chamber, whereby the very adverse emergence of bridges or channels is counteracted in the following zones · From the water vapor contained in the raw gas auskonden-Biert only a small part in the pressure damping, so that the raw gas cools only a little it is possible, and useful, to use the raw gas after leaving the reaction vessel, as already known, for waste heat steam generation.

The heat requirement for pre-drying the raw lignite in the pressure damping zone is when using the heat of Dämpfungswassera for preheating the raw coal to 363 K only 550 - 65O kj / kg in the attenuation abgeschiedeßes water, this amount of heat of the waste heat steam generation is withdrawn by the raw gas. As a result, the use of high-pressure steam can be omitted. This finding characterizes the high value of the proposal for the use of raw gas for pressure damping. The comparatively low heating requirement for coal drying is due to the fact that neither the hot coal nor the hot condensate produced during pressure dewatering results in additional heat losses for the process of pressure deaeration and gasification in combination with the pressure damping.

Another essential feature of the inventive concept is the strong flow through the mixture of steam and the gas components of the raw gas through the mixture of steam, whereby the heating rate of the coal, the chemical process of carbonization and the removal of forming gas constituents and thus the entire process of the lyopolar and capillary Dehydration be accelerated. These advantages also occur when hot, steam-containing, in particular phenol-free, raw gases are used, which are produced in other pressure processes of the partial oxidation of fuels, and are also largely effective if the dewatered coal is used more relaxed after pressure damping *

Since only a small part of the vapor gas contained in the raw gas is required for the pressure damping process, it is possible to use only partial flows of the raw gas generated in the coupled gasification process for the pressure damping. In this case, the raw gas may not have a partial pressure of water vapor of 0.5 MPa during pressure damping.

stride.

It is already known to use for degassing and post-drying of the fuel only a partial stream of the raw gas generated · This is a so-called carbonization and the rest of the gas generated in the gasification is withdrawn as tar-free, so-called clear gas. When using lignite this smoldering gas is low in dust, while the clear gas carries larger amounts of dust. The separation of the raw gas generated in these two streams also allows the use of a variable heating rate in the after-drying and degassing, as it is also known per se, which is advantageous for the gentle further treatment of the fuel, in particular in the degassing zone.

The carbonization gas can be advantageously used by its Dusting low for pressure damping, wherein it is introduced after flowing through the degassing s- and post-drying zone immediately after saturation in the damping chamber and generally flows through the coal bed from bottom to top.

If only the clear gas used for the pressure damping, so there is the advantage that this Klargas.ru with such a high temperature can be withdrawn from the reduction zone, that it is phenol-free and so the resulting damping water does not burden the Entphenolungsanlcge. In this case, the withdrawn clear gas is only then introduced above the coal bed in the damping chamber after it has been cleaned of dust and saturated with water. "When using a common pressure vessel for Druckdämpfungs- and Ent- and gasification process proceeds in this case so that the gas outlet between pressure damping zone and liachtrocknungszone is arranged ·

With separate deduction of smoldering and clear gas it is too

possible to reunite both types of gas for the pressure damping · It is expedient to clean the clear gas before the union or the mixed gas after the union of dust and to saturate with damping water.

To accelerate the dewatering process in the pressure damping and the raw gas or the gas of the respective partial flows can be initiated superheated in the pressure damping chamber

 Furthermore, it is possible to bring a raw gas partial stream to such a high temperature that the attendant phenols are destroyed and this partial stream is used after saturation with water for pressure damping

 Due to the very gentle drying and degassing of the raw lignite coal according to the method of the invention, an undecomposed, abrasion-resistant coke can be withdrawn after pressure degassing. In order to produce a solid smoke-poor fuel, the degassing, after-drying and optionally subsequently the pressure damping is carried out separately from the pressure gasification with hot rinsing gas containing as much water vapor as possible. The degassed fuel is then cooled, relaxed and can be used as coke. The coke produced, or a partial stream thereof, can be used for the pressure gasification carried out in a separate room, the compressed gas produced or a partial flow of this being used for degassing, drying and pressurizing.

f) embodiment:

The invention will be explained in more detail below with reference to four exemplary embodiments.

Example 1:

The raw lignite with a particle size of 5-60 mm, 57 % water content and approx. 293 K is transported to a bunker and heated to cä «363 K by steam and possibly by atomizing pure water * from there the raw lignite reaches the coal sluice. is discontinuously covered to a pressure of 2.5 MPa and slid into the vessel for the pressure damping of the raw lignite coal. In the. Coal sluice, the raw lignite coal is further preheated to 393-423 K with a partial flow of the damping agent or through approximately 490 K hot damping masses In the pressure damping vessel Dampjf with a temperature of 495 K is supplied above the coal bed.

At this temperature of the damping agent, it is possible to dewax the raw lignite at 60-90 minutes steaming time to about 25 % HoO. "By dewatering the raw lignite only up to a residual water content of about * 35%, the damping time can be lowered to 30 - 40 minutes "This allows the pressure damping vessel to be kept relatively small. The water draining from the coal and condensed by the damping agent is separated by a suitable device in the damping vessel. In this process, the fine grain produced is water. «This cleaning effect is intensified by atomizing circulating approx. 490 K hot damping water in the damping vessel. The dehydrated coal is 470 - 500 K.

63O evenly heated and continuously into the pressure vessel for post-drying, degassing and gasification, which has the same pressure of 2.5 MPa promoted. Compared to a previously common feed of a fuel with about 303 K and 20 % H ₂ O become

with the pressure-damped coal ca * 370 kJ / kg dry

20 846 5

coal, based on 20 % H ₂ O, heat more out in the degassing and gasification vessel. This heat is sufficient to dry the Koh0.e of about 35 % to about 20 % H ₂ O without heat extraction from the degassing and gasification process. The drying of the coal then takes place to:

- About 81 % by Y / arms of the pressure damping

• about 66% of which in liquid form in the pressure vessel

• Of which about 15% due to evaporation in the pressure de-and gasification reactor

and

- 19 % by evaporation by means of heat from the pressure deaeration and gasification process.

Characterized in that the coal pieces heated evenly; without

65O latent water content range and without hardened grain surface by the Luftatmosphäreneinfluß get into the degassing and gasification vessel and here at 2.5 MPa (vapor volume only about 1/21 compared to normal atmosphere) are dried, this drying is carried out without significant damage to the carbon grain. The excess approx. 490 K of hot damping water is released to approximately atmospheric pressure. The resulting approx. 373 K hot steam and the equally hot water serve to heat the raw coal used to approx. 363 K.

Water vapor with a saturated steam state at 2.5 MPa and approx. 495 K is used as the damping agent. If the steam present has a higher pressure and a higher temperature, it is depressurised before entering the damping vessel and saturated with damping water.

The heat requirement in the damping vessel is 1 100 kJ / kg

discharged water. The steam supply is controlled so that always flows a small amount of residual steam together with the resulting CO in the Druckinkohlung in the degassing and gasification vessel. The resulting damping water has only a very low phenol content.

Example 2:

The raw lignite with a grain size of 5-60 mm, up to 57 % water content, is hydraulically conveyed to the gasification plant with 370 K of hot dampening water at atmospheric pressure and preheated to 363 K. From the bunker it then passes through a coal sluice in a large pressure vessel, in the lower part of the coal in the fixed bed at a pressure before.- 2.5 MPa is gasified. The gas formed flows upwards in countercurrent to the coal and forms successively the following zones:

Ash zone, oxidation zone, reduction zone, degassing zone, post-drying zone, damping zone.

The dripping in the pressure damping zone from the raw lignite water saturates and supersaturated (mist formation) the rising raw gas. The excess damping water enters the following zones and removes the heat necessary for its evaporation. The evaporation of the damping water can cause disadvantages of the increased oxygen and fuel requirements, the deteriorated decomposition of the gasification steam and the increased COg content in the raw gas. With a high proportion of excess water, these disadvantages can be avoided by installing devices for separating the pressurized water from the coal between the pressure damping zone and the after-drying zone. With the separated damping water, a portion of the dust accumulated during the damping and entrained by the gasification gas is removed

Damping water is decompressed and used for hydraulic transport of the raw coal to the bunker · The lignite is dewatered in the damping room to approx. 35 % water content and subsequently dried in the oak zones, degassed and gasified. The Robgas occurs in the upper part of the pressure vessel and reaches the waste heat steam generation. In this embodiment, the raw gas from the degassing and gasification process of the Pestbettdruckvergasung with 2.5 MPa, ca · 473 K water vapor saturated serves as a damping agent. The saturated

3 raw gas has a water content of 1.6 kg / m iJ, The heat requirement in the damping zone is about 580 kj / kg of separated water.

After damping, the raw gas has a water content of about 1.3 kg / m iJ. and a temperature of approx.

468K up. The heat recovery steam generation (0.5 MPa steam) is limited by the heat given off by the raw gas during the damping by the hot raw gas. Due to the coal bed, raw gas flows continuously, which guarantees a quick warm-up of the coal and an immediate COp discharge. This shortens the damping times. "Hydrocarbons condensed out of the raw gas improve the bulk material movement.

A disadvantage can prove in the present example that the discharged damping water is highly phenolhaltig and leads to an approximately 50 % higher load of Entphenolungsanlage .. From the change in the parameters of the raw gas in the damping zone can be seen that only a small part of the im Raw gas contained vapor is needed for the pressure damping. This makes it possible to use only a partial flow of the raw gas for the damping, resulting in the following variants;

1.A tarry and phenol-free high-temperature clear gas is withdrawn from the reduction zone of fixed-bed pressure gasification. The clear gas is saturated with water, cleaned of dust as necessary, and then introduced into the pressure vessel above the coal bed for pressure damping. It flows in the direction of the coal path through the damping zone and leaves the pressure vessel together with the separately guided carbonization between Druckdämpfungs- and after-drying zone. An increased load on the dephenolization plant due to the dampening water does not occur «

2. When using the dust-free carbonization for pressure damping this flows directly countercurrent to the carbon route from the Uachtrocknungszone in the pressure damping zone, here is saturated by the damping water and leaves the pressure damping zone above the coal bed. The damping water is heavily phenolic. The condensed hydrocarbons improve the bulk material prevalence and are sometimes discharged with washed-out fine dust from the effluent damping water *

Example. 3:

In this embodiment, raw lignite is conveyed with a grain size of 5-12 mm, up to 57 % water content and preheated to 3.63 K from the bunker in alternation in two pressure vessel. The two pressure vessels have the following tasks in chronological order:

Absorption of the coal in the unpressurized state, covering the raw coal with steam to 10 MPa, dewatering of the coal at 583 K in 15 minutes to 35 % water by pressure damping and deposition of the damping water, relaxation to the pressure of the arranged under the pressure vessel degassing vessel of 2.5 MPa and feeding the coal into the degassing vessel. The two pressure vessels supply the pressure degassing in turn

20 8 4 6 5

Fuel.

In the degassing vessel gentle post-drying and degassing is carried out by purge gas, which is produced by a fluidized bed pressure gasification. The coke produced in this way passes metered to the fluidized bed gasification process.

The generated gas is used for the utilization of the sensible and latent heat after the cleaning of dust partly as purge gas the degassing process and partly the waste heat »use.

Example 4ί

In the fourth embodiment, raw lignite with a particle size of 40 - 60 mm, preheated to 58% water content in a bunker to 363 K, conveyed in coal locks "covered with hot water and alternately introduced into a pressurized water flow of 3 MPa and 500 K.

By means of the pressurized water, it is conveyed to a pressure-reducing vessel and pre-dewatered to 48 % water content during hydraulic delivery. In the pressure damping vessel, the coal is separated from the pumped liquid and steamed with saturated steam of 2.5 MPa to 35 % water content. The damping water flows together with the pumped liquid at a temperature of about 485 K from. From this hot water, a partial stream is separated with the fine grain in a hydrocyclone. The upper section of the hydrocyclone is returned to the parameters 3 MPa and 503 K via a pressure booster pump and a heat exchanger and used again for the hydraulic conveyance of the raw coal. The pre-dried coal to 35 % Y / assergehalt passes from the pressure damping vessel in the pressure degassing vessel, is here gently dried by purge gas and degassed to a temperature of 1 000 K. The coke produced is cooled, relaxed and recovered as a low-smoke fuel.

Claims (32)

-to- 2 0 8 4 6 Srfindungsansprueh 1 · A process for pressure deaeration and gasification of Lignite, especially lignite, characterized in that granular lignite in a known manner in a pressure damping chamber with a pressure> 1 MPa, introduced here by a damping agent 'partially dehydrated and druckinkohlt viird, and approximately uniformly a temperature> 423 K is heated and the pretreated coal passes without relaxation to a pressure <0.5 MPa and without cooling the coal ^{to a} temperature <423 K, in the Ent- and Verga-8ungsreum in which the coal by their high heat content is further gently dried and then in a known V / iron the Druckentgaeung and pressure gasification takes place. 2. The method according to item 1, characterized in that the pressure damping chamber always has the same pressure as the pressure-degassing and gasification chamber and the pretreated carbon is continuously from the pressure damping chamber in the pressure deaeration and gasification chamber · 3 · Method according to item 1, characterized in that prevails in the pressure damping chamber during the pressure damping a preferably higher, possibly also lower pressure than in the degassing and gasification space _. However, at least one pressure of> 1 MPa is present and after the pretreatment of the coal the pressure damping chamber on the pressure of the degassing and gasification vessel and / or is covered and the coal discontinuously reached the degassing and gasification chamber 4. The method according to item 1 and 3 », characterized in that the pressure damping takes place in a vessel or in several vessels and the vessel or the vessels at the same time the coal, from the pressureless bunker in the pressurized Ent- and gasification vessel slid and thereby in the pressure damping chamber in a predetermined rhythm, a relaxation to atmospheric pressure, absorption of the raw lignite, a stringing on damping pressure, a pressure damping and water separation, making the pressure equalization to Druckent- and -gasification space and the emptying of the partially dewatered coal in the degassing and gasification · Method according to points 1 and 4, characterized in that the coal pre-dewatered by pressure damping is after-dried with superheated steam. 6. The method according to item 1, 4 and 5 », characterized in that the pressure loss in the Kohiesschüttung leaving residual steam with the discharged GOo and at a Uachtrocknung the coal with superheated i. Steam effluent steam is used as a gasifying agent. 7th method according to item 1 and 2, characterized in that the pressure damping and the pressure deaeration and gasification is carried out in a common pressure vessel · Process according to items 1 to 7, characterized in that the water dripping from the coal in the damping chamber purifies the coal from the very small amount of finest particles and that the attenuating water returned to the reactor is atomized above the carbonisation in the damping chamber to enhance this effect · 9 · Method according to item 1 to 8, characterized in that the damping water is deposited continuously in the damping chamber and a steam or hot water production is supplied. 10 «method according to item 1 to 9, characterized in that the damping water is expanded to atmospheric pressure Bird and the resulting steam and / or hot water is used to preheat the lignite coal. 11. The method according to item 1 to 10, characterized in that the expanded hot water for hydraulic conveying of the raw lignite to the process upstream bunker is used with simultaneous heating of the raw lignite β 12. Method according to items 1 to 3 and 7 to 9 », characterized in that the damping water deposited under pressure is used for the hydraulic promotion of the raw lignite coal from the coal lock to the pressure damping chamber and in this case already a pre-damping of the coal. 13 · Process according to items 1 to 3, 7 to 10 and 12, characterized in that the raw lignite coal in the coal sluice by a partial flow of the damping means and / or by hot steam ungsviasser heated in advance 14 · Method according to points 1 to 13, characterized in that for pressure damping saturated, possibly slightly superheated steam is passed into the damping chamber « 15. The method according to item 1 to 14 », characterized in that steam is introduced as damping means, which is saturated at the selected damping pressure with Dämpfungsviasser, in such an amount in the damping chamber above half of the coal bed, that always a small amount of residual steam together with at the carbonification of the coal produced gases flows into the degassing and gasification room » 16. Method according to items 1 and 2, ie 7 to 15, characterized in that the jacket steam produced in the water jacket of the pressure degassing and gasification drum serves preferably for pressure damping. 17 · Process according to item 1 to 13, characterized in that the pressure damping of the granular crude lignite with hot, saturated or only slightly superheated steam containing gases of partial oxidation of fuels under pressure with a partial pressure of water vapor> 1 MPa, wherein the hot water vapor-containing gas to draining coal constantly flows through and condenses only as much of the gas entrained steam in the pressure damping that a water vapor partial pressure of 0.5 MPa is not exceeded and that the water vapor-containing gas in the Druckinkohlung resulting gases from the .Druckdämpfungsraum and the process of lyopolaren and accelerated capillary water release. 18 · Method according to item 1, 2, 7 and 17, characterized in that the pressure damping, gentle Hachtrocknung, degassing and gasification takes place in a pressure vessel s wherein the crude gas generated in the lower part of the vessel by pressure gasification flows upwards in countercurrent to the coal and thereby in the coal charge in directly merging zones the degassing, gentle 'drying and pressure damping performs. 19. The method according to item 1, 2, 7, and 17, 18, characterized in that by means of the raw gas, a part of the votes in the pressure damping of the raw lignite coal water in the form of fine droplets from the pressure vessel is performed. 20. The method according to item 1, 2, 7 to 13 and 17 to 19, characterized in that between the damping and Hachtrocknungszone the dripping water is separated by suitable devices. Method according to item 17, characterized in that the water vapor-containing gas of the partial oxidation of fuels before being fed into the damping chamber saturated and purified by entrained dust and condensed hydrocarbons. 22. The method according to item 17 to 21, characterized in that the water vapor-containing raw gas used for pressure damping is saturated by the deposited in the pressure damping of the carbon water and cleaned of dust. 23 "process according to .Punkt 17 and 19 to 22, characterized in that when using hot water vapor-containing gases of the partial oxidation of fuels that are phenol-free, and when using superheated steam containing gases introduced above the Kohles'pfüttung in the damping chamber« earth , i 24th method according to item 17 to 20, characterized in that only a partial flow of the raw gas produced in the degassing and gasification room is used in the degassing and gasification for further gentle drying and degassing of the pre-dewatered by pressure damping grains. 25 »Process according to item 17 to 20, 22, and 24, characterized in that the partial gas stream, with which the gentle Hachtrocknung and degassing is performed, and which has only a low dust content and many hydrocarbons, then used for pressure damping of the raw carbon grains becomes· 26. The method according to item 17, 19 to 23, characterized in that a partial stream of the raw gas produced in the degassing and gasification chamber is withdrawn from the reduction zone as tar-free clear gas and then used after saturation and, if necessary, cleaning of dust for pressure reduction of the lignite coal '' 27 · Method according to item 17, 19 and 20, 22 and 23 and 26, characterized in that the clear gas in a such a temperature is withdrawn from the reduction zone or a crude gas partial stream is brought to a high temperature such that the vapor accompanying the gas before being introduced into the damping zone is phenol-free 28. The method according to item 17, 19, 21 to 23 and 25 to 27, characterized in that after the pressure damping of the granular lignite coal with hot water-vapor-containing gases of the partial oxidation of fuels, 'the dehydrated grains relaxed and intestines are further used as required'. 29. The method according to item 1 to 6, 8 to 17, 19bis 21, 22, ä3, 26 and 27, characterized in that the pressure gasification process is carried out separately by a metering device or in a separate vessel from the processes of pressure damping, post-drying and degassing · 30. The method according to item 1 to 6, 8 to 17, 19 to 21, 22, 23, 26, 27 and 29, characterized in that 990 'the coke obtained after the pressure degassing process is cooled and relaxed and recovered as low-smoke fuel * 31. The method according to item 1 to 6, 8 to 17, 19 to 21, 22, 23, 26 _} 27, 29 and 30, characterized in that the coke produced or only a subset for separate, carried out pressure gasification and the generated hereby Gas or a partial flow of this is used as purge gas for degassing, ITachtrocknung and pressure damping * 32. The method of item 1 to 6, 8 to 17, 19 to 21, 22, 23, 26, 27 and 29 to 31, characterized in that "part of the ash is removed from the coal during the pressure damping.