DE1045030B - Process for generating flammable gases - Google Patents

Description

GERMAN

The invention relates to a method for generating combustible gases from solid, liquid or gaseous fuels by reacting the fuel in a finely divided state with a free one Oxygen-containing gas and optionally endothermic gasifying agents.

Gasification processes in which the fuel is finely divided with oxygen or an oxygen containing gas is implemented in suspension, are known per se in many modifications. To today this process has generally been carried out in such a way that the reaction between fuel and running the gasification means at substantially constant pressure so that the production gas has to do external work because of the volume increase resulting from the implementation, by which the reaction temperature is lowered.

It has also been proposed that the finely divided fuel with an oxygen-containing gas in to implement the cylinder of an internal combustion engine, the result of the increase in volume resulting pressure increase is used to move the cylinder piston. The consequence of this is that the temperature inside the cylinder also has a decreasing tendency, because in this case too the useful gas generated has to do some external work. This temperature decrease is very undesirable, because the intended gasification reactions proceed faster, the higher the reaction temperatures lie.

It has been found that a better synthesis gas yield can be obtained if the Gasification reactions can take place at constant volume. If the production gas during the Gasification cannot do any external work as a result of its expansion, a higher reaction temperature arises a. Because the specific heat of the reaction products is smaller at constant volume than that at constant pressure is obtained by maintaining the constant reaction volume higher temperatures compared to the procedure in which the pressure is kept constant. The consequence of the higher temperature is a better and faster reaction of the carbon with the endothermic reacting gasification agents, for example water vapor. On the other hand, you can if you can wants to maintain the same degree of carbon gasification as the previous procedure, with less Oxygen get by per kg converted fuel.

The invention accordingly consists essentially in the fact that the volume of the reaction products of a gasification of finely divided fuels with oxygen during the as a result of the reaction on-process for production
flammable gases

Applicant:

Koppers Company, Inc.,
Pittsburgh, Pa. (V. St. A.)

Representative: Dr.-Ing. H. Leithäuser, patent attorney,
Essen, Bertoldstr. 9

Claimed priority:
V. St. v. America dated 2L December 1955

Ernest E. Donath, Pittsburgh, Pa. {V. St. Α.),
has been named as the inventor

the pressure increase that occurs. The intended gasification reactions are running at the practical implementation of the procedure in a closed volume starting with a considerable Increase in pressure as a result of the increase in volume and as a result of the increase in temperature occurs. Only after the gasification reactions have essentially ended are the useful gases generated taken from the previously closed reaction chamber.

The reaction within the closed reaction space is explosive, i. i.e., it is marked due to a very fast and very violent imperfect combustion of the finely divided fuel with the oxygen.

Practically all carbon-containing substances can be used as fuels for the process according to the invention in question. From the group of solid fuels, the bituminous coal, anthracite, lignite, Lignite, lignitic coal, peat, coke, charcoal, wood, etc. From the group of liquid fuels Possible mineral oils, crude oil, gas oil, distillation products of crude oil and crude oil fractions, coal tar, Lignite tar, shale oil, smoldering tar

and the like. Finally, from the group of gaseous fuels that are used for the process according to the invention come into question, methane, ethane, propane, butane or mixtures of these gases, also natural gas, residual gases from synthesis and the like.

The drawing shows two devices for carrying out the method according to the invention.

Fig. 1 shows a device for gasifying a solid fuel during

809 680/269

Fig. 2 a device for gasifying a liquid or gaseous at normal temperature Fuel shows.

In both cases, the entire gas generating device consists of a reaction chamber 2, which is of a jacket 16 is surrounded, which is arranged at such a distance from the wall of the reaction chamber is that a free space is created, which is used for the circulation of a coolant. The coolant, for example water, is introduced through line 10 into the cooling jacket. Of course you can also choose a different coolant. However, water is particularly useful because you can get out of it the water can use steam formed in the gasification reaction. The developing water vapor is withdrawn through line 11 and enters the steam collector 12. The entrained there Water runs back through line 12 & back into the cooling jacket. The useful steam is by conduction 12 α taken.

The cooling jacket is intended to prevent overheating of the reaction chamber walls and to keep them at a sufficient level Keep the temperature low so that it can withstand the attacks of both oxygen and the Implementation formed sulfur compounds can withstand. There have been coolant temperatures between about 93 and 260 ° C or even slightly higher proved to be advantageous. At these temperatures the water vapor used as a gasifying agent is not yet condensed, and besides, the Steam obtained in the cooling device at such a pressure that it is necessary for the gasification reaction or can also be used as carrier vapor.

Before using the gasifier for the first time, the very powerful pressure vessel is used 2 first brought to a temperature of about 200 to 210 ° C by passing water vapor through 10 is introduced into the cooling jacket. Of course, you can also use the reaction space on others Way to heat up to the starting temperature. Thereafter, the heated reaction chamber is expediently rinsed and filled with steam, which is fed through line 1 and optionally can flow out of the reaction chamber again through line 13. After the steam valve in the pipe 1 is closed, the finely divided solid fuel, e.g. B. finely ground bituminous coal, with relatively high speed from the boiler 5 by means of a carrier gas through the line 8 introduced into the reaction space. The carrier gas is primarily a gas containing free oxygen, which can optionally be saturated or enriched with water vapor. The boiler 5 is the one to be gasified Fuel has already been supplied through line 4 beforehand. The blown gas is by pipe 6 is passed into the boiler 5 and blows the solid fuel therefrom through line 8 into the reaction chamber 2 a.

As soon as the desired initial pressure is reached in the reaction chamber, which is approximately in the range between 2 and 20 atm, advantageously about 3 to 10 atm, the valve 7 in the line 8 is closed. The one in that The suspension of gaseous and vaporous fractions located in the reaction space is then by means of the Spark plug 9 ignited, which is operated electrically in a known manner. There are other possibilities as well given the ignition of the mixture, for example by means of an electrical resistance heater or by means of the introduction of self-igniting chemicals or the like. The reaction between the gasification components begins before the suspension has the opportunity to settle at the bottom of the reaction chamber 2 to discontinue. This reaction is usually from 0.1 to 5 seconds, and in most cases from 0.5 to 2 seconds completely to an end, so that from this point on the temperature begins to drop to a value at which practically no more reactions take place.

At the high temperature resulting from the initial reaction, the endothermic reaction takes place between the water vapor and the fuel decreases particularly quickly. As a result of the gasification reactions, which are associated with an increase in volume, the pressure rises about ten times or even

¹ S to a higher multiple of the initial pressure. As the cooling becomes noticeable, the pressure drops again. After a certain time, about 5 seconds to 5 minutes, in particular after about 10 to 60 seconds, the gas mixture in the reaction chamber has cooled to such an extent that it can be discharged through the valve 14 into the synthesis gas line 15 without the risk of corrosion the valves. Since the synthesis gas pressure is usually considerably above normal pressure, approximately between 5 and 50 atmospheres, in particular 10 to 25 atmospheres, a certain part of the gases generated remains in the reaction chamber after the valve 14 has been opened and the reaction products have flown out of the reaction chamber return. This residual gas can either be expanded to normal pressure and then compressed and mixed with the synthesis gas, or this residual gas can also be flushed out of the reaction chamber by means of additional steam. If large-volume gasifiers are used, the synthesis gas can be displaced from the reaction chamber in a simple manner by spraying water into the reaction chamber 2, which evaporates violently and then displaces the synthesis gas. After valve 14 is closed, the excess water vapor can be removed through line 13, thereby making the device ready to repeat the gasification cycle.

In the case described above, the fuel and the oxygen-containing gas are simultaneously in the Reaction space has been introduced. This is not absolutely necessary. One can also do the individual Add the gasification components to the reaction chamber one after the other. For example, you can Fill the gasification chamber beforehand with pressurized oxygen and use the preheated coal dust Blow steam into the reaction chamber. Instead of the water vapor, another carrier gas can also be used to get voted. The coal dust can also be introduced into the reaction space by means of a suitable inert gas blow in, in which there is already a mixture of oxygen and water vapor. Finally, you can first fill the gasification chamber with coal dust and oxygen and then blow in additional amounts of oxygen and steam so that the coal dust forms a suspension is whirled up. Finally, it is also possible that the ignition of the mixture is not in each case on End of such a filling causes. For example, if you already have oxygen in the gasification room and water vapor and then blows in the fuel, you can start the ignition effect after only part of the solid fuel is introduced into the reaction chamber. The other Part can be brought in after ignition. In

5 6

In this case one must of course have a higher pressure after the reaction space with water vapor

spend for the carrier gas, because it is filled by the in, through the line 4, at the end of which

A spray nozzle 4 a is located between a spray nozzle 4 a that has run off in the reaction chamber, into the reaction chamber 2

gassing reaction an increase in pressure has occurred. introduced. At the same time, line 6

The oxygen consumption in the case of solid fuel brings the oxygen or the oxygen-containing gas in about 0.31 to 0.87 Nm ³ kg, preferably 0.43. When the desired initial pressure reaches up to 0.62 Nm ³ / kg, solid fuel, when this is off, the valves 7 α and 7 b are closed. Anbituminous coal exists. The reaction takes place, the mixture of fuel, oxygen and C + HO = CO + H ¹⁰ water vapor is ignited by actuating the ignition device according to equations 9, the reactions if

j ^{2 2} , for example, as the simplest representative of the utn

2C + O = 2CO adding fuel selects the methane, according to

² 'run the following equations:

The synthesis gas yield per unit weight of fuel qjt _i_ tr O = CO + 3H

substance is greater in the first reaction than in the 15 _{un (} j 42 2

second. The contribution of the first reaction increases in CH + ¹ O = CO + 2H

the extent to which the heat losses of the gas generator 422 2 ·

lose weight. The heat losses from the gas generator The amount of oxygen that goes into these reactions

again decrease when the volume of gas expended is about 70 to 150%, preferably

producer is lower. While you actually have a 20 80 to 120%, the amount of oxygen that would be necessary,

Satisfactory conversion in a test gas to the entire carbon content of the fuel

producer was able to determine that its volume only converts 3 to into carbon dioxide. 5 was 1, so did the oxygen consumption in this

Case about 35 Nm ³ per 100 Nm ³ useful gas produced Example 1

the end. For a technically usable system one will need 25 A finely ground coal with the following elementary

Therefore, you have to choose larger reaction spaces, the analysis of which:

Volume is greater than 1.5 m ^s and more desirable- ν ui ± α η λ πλάι

^ö .. "1 r 1. · £ β λ * · ι c carbon 74.94%

even larger than 5 to 6 m ³ . You can also use hydrogen 5 03%

operate several such reaction rooms in parallel, _c " _c '" _{no /}

,.,, »,,.,., /, Λ, oxygen 5.70%

so that a better continuity in the gas generation 30 ς h f 1 153 ° /

and in the subsequent cleaning of the synthesis gas ο ,. ,, "i / sQo /

receive. Ash 1121%

In order to ignite the reaction mixture

Easier, one can near the spark plug a whose grain size was chosen so that 90% passed through a combustible mixture of oxygen and a combustible 35 200-mesh sieve, was introduced with high bleeding gas, the combustible gas being velocity A small amount of the synthesis gas produced is blown into a stable pressure vessel made of steel by means of oxygen. The volume of the can turn. You can also import substances, the boiler was 1.4 m ^s . The boiler had a start that catalytically accelerated the combustion. The temperature of 210 ° C. There was already an amount of ignition mixture in the boiler, which is expediently present in water vapor. When introducing the reaction chamber, the pressure inside the boiler of the fuel to be converted depends on the type of fuel. on 3 atü. Approximately 0.561 Nm ^{3 of} oxygen were required. The solid fuel is required in finely divided form and 0.2 kg of steam per kg of coal. The mixture applied. It is expediently so fine that it is then ground up by a spark plug for ignition so that at least 70% is brought through a 200 mesh. After cooling down, pass the reaction sieve through it. It is desirable, however, that the products were drawn off a synthesis gas which, as a whole, has a fuel smaller than the mesh of the following composition:

such sieve. _ΛΓ Carbon dioxide 3.5 percent by volume

As already mentioned, it is advantageous to use the _w , J 'nan

. ,. ,. ' . - · ι_ j. ι.- · · i_ hydrogen 33.9 ,,

gassing reactions in the case of an over-atmospheric 50 ",,,,. ',

S .. ° ,, T ^. τ-, j. . ^{,, r} . . , Carbon monoxide 61.6 ,,

Start printing. But this condition is not un- ". . " ^J '"

to be complied with to a limited extent, because it may also be hydrogen sulfide 0 * 2

possible to start with normal pressure. Essential ' "

is only that the reaction space volume up to 1000 Nm ³ CO + H ₂ were 528 kg coal, 300 Nm ³

Keeps the course of the gasification reactions constant. 55 oxygen and 105.6 kg steam are consumed.

The walls of the reaction chamber must have been obtained from a similar result if one took place

Material must be made which not only consists of the specified hard coal other solid fuels

mechanical strength, but used such as anthracite, lignite, lignite, peat,

also the high temperatures and changing pressure coke, charcoal and wood,

exposed to ken, and chemically not 60

is vulnerable. It has been shown that the Example 2

knew stainless steels or other appropriately finely ground coal of the same type as im

Prepared metals for this purpose use Example 1 with a grain size that 95% through a

can. 200-mesh sieve was passed inside the

For the conversion of a liquid or gas steel boiler with air, the oxygen content of which is 48%

shaped fuel used device after was enriched, and steam in compliance with a

Fig. 2 is implemented in the same way with constant volume in essential points. Before starting the

of the device used for the gasification of a settlement, the pressure in the reaction chamber was 5 atmospheres.

solid rod-shaped fuel according to the invention. Immediately before the start of the reaction, a

is needed. The gaseous or liquid fuel 70 with small amount of the previously generated synthesis gas

Claims (8)

1 MS 03 oxygen injected into the reaction chamber. Then the mixture was ignited. For the gasification, about> 0.579 Nm3 of oxygen and 0.15 kg of steam were required per kg of coal. The degree of carbon gasification "is 85%. The synthesis gas produced had the following composition: Carbon dioxide .......... 2.7 percent by volume hydrogen 26.3" carbon oxide 46, 6 "nitrogen 24.2" * e hydrogen sulfide 0.2 "After conversion of the carbon dioxide by means of steam to hydrogen and carbon dioxide and removal of the carbon dioxide and sulfur as hydrogen, the largest gas is suitable for the ammonia synthesis. In Example 1 · βο steam was gasified in a StaW vessel with oxygen, but the volume of the steel vessel was 5.6 ms. When the reaction components were introduced, the temperature of the steel vessel was 223 ° C. The pressure was initially 4: a1) above Only 0.499 Nm3 of oxygen and 0.2 kg of steam were used per kg of coal. The result was a carbon four-gasification rate of $ 0%. The synthesis gas produced had the following composition: 3 ° carbon dioxide 3.1 percent by volume hydrogen 35.2 coals oxide 60.8 "nitrogen, 0.7 hydrogen sulfide .0.2 per 1000 Im8 CO + H2, 49.6 kg coal, 250 Nm3 oxygen and 99.2 5 cg steam were required. Instead of water vapor, carbon dioxide can also be used in the gasification reactions. The synthesis gas produced then has an essential content of carbon dioxide rather than carbon dioxide. EXAMPLE 4 The 1.4 ni3 holding tank is filled with a mixture of water vapor and oxygen, so that the partial pressure of the water vapor is 1.5 at and that of the oxygen is 3.5 at. The temperature of the reaction space is 210 ° C. A heavy fuel oil is injected into the reaction vessel under a pressure of 200 atmospheres, in an amount of 14.4 kg per Nm3 of oxygen. The mixture is ignited after about 40% of the total amount of oil required for conversion has been introduced. The rest of the oil is injected after ignition. Almost all of the heating oil is converted into synthesis gas. After a cooling period of 25 seconds, the outlet valve is opened and water is injected into the reaction chamber. The gas is flushed out by the developing water vapor. The resulting synthesis gas has the following composition: carbon dioxide 2.7 percent by volume hydrogen 46.4 carbon oxide 48.3 nitrogen 0.8 hydrogen sulfide 0.5 methane 1.3 "35 Similar results are obtained if the largest part of the (steam - replaced by carbon dioxide. EXAMPLE 5 The steel kettle is loaded with water vapor and oxygen Sn in such a way that the partial pressure of the water vapor is 1 at 'and that of the' oxygen is 4 at. at about 226 ° C. From a special high pressure boiler, natural gas is injected into the gasification boiler in an amount of 2 parts by volume of natural gas per part of oxygen. Immediately after ignition, a mixture of 1 part oxygen and 1 part previously produced is produced. Synthesis gas' through an auxiliary nozzle into the "reaction vessel near the spark plug." NaOh - the ignition propagates - the reaction propagates through the whole mixture, 1WODeI a practically complete conversion of the methane takes place. The cooling of the synthesis gas and the subsequent process steps are the same as in Example 4. The synthesis gas has the following composition: carbon dioxide 2.2 volume percent hydrogen 65, 2 carbon oxide 30.1 nitrogen 1.3 methane 1 , 2 Instead of part of the natural gas, you can also use liquid fuels, such as crude oil, petroleum, petroleum distillates, coal tar, brewing tar, residual oils, smoldering tar or other hydrocarbons such as ethane, propane, butane or the like, in the reaction chamber to form synthesis gas -zen. Patent to ρ r ü οηέ ·. 1. Process for the production of flammable gases from solid, liquid or gaseous fuels by converting the fuels in a finely divided state and floating with a free one Oxygen-containing gas and optionally endothermic gasifying agents, thereby marked that the volume of reaction pr-otMcte -during -the pressure increase occurring as a result of the implementation kept constant -will. 2. The method according to claim 1, characterized in that a suspension of the finely divided Fuel in the oxygen-containing gas in brought to reaction in a closed reaction chamber - and there in a superatmospheric condition Pressure maintained at constant volume until the reaction products are removed from the chamber will. 3. The method according to claim 1 or 2, characterized in -that -the initial pressure of the reaction 2 to 20 atmospheres, preferably 3 to 10 atmospheres, amounts to. 4. The method according to any one of claims 1 to 3, characterized in that the suspension according to Introduced into the reaction chamber by an ignition device, e.g. B. a spark plug ignited will. 5. The method according to claim 4, characterized in that in addition in the vicinity of the ignition device a small amount of a mixture of Oxygen and fuel gas are introduced into the reaction chamber for the duration of the ignition process will. 6. The method according to any one of claims 1 to 5, characterized in that the oxygen-containing Gas pure oxygen, air with increased oxygen content or air can be used. 7. The method according to any one of claims 1 to 6, characterized in that the endothermic reacting Gasifying agent steam, carbon 10 dioxide or a mixture of both is used. 8. The method according to any one of claims 1 to 7, characterized in that the reaction chamber rinsed with steam after the reaction products formed during the reaction have been removed will. 1 sheet of drawings