DE962922C - Step process for the production of a combustible gas from liquid hydrocarbons and water vapor - Google Patents

Description

The invention relates to the production of combustible gases from hydrocarbons by a process in which the hydrocarbons are in vapor form in conjunction with Water vapor are passed through a catalyst layer at a relatively high temperature (For example, the catalyst may be any of those described in British Patents 648,965 and 666,524 be), which leads to the formation of a gas that can be used as a luminous gas either alone or mixed with coal gas is suitable.

The reaction is endothermic, and it is moreover essential for the process to operate effectively necessary that the temperature in the contact zone of the hydrocarbons and the catalyst should be relatively high. For this purpose it was proposed to heat the catalyst layer, the process being carried out in cycles or in stages. Doing this during part of the cycle of water vapor and evaporated hydrocarbons through the catalyst layer and draw heat out of it, while in the other part of the cycle the supply

drove off by water vapor and hydrocarbons and bite air through the catalyst layer is blown for reheating.

Suitable hydrocarbons for such a process are mineral oils, other hydrocarbons, which are liquid at ordinary temperatures or gaseous hydrocarbons. In the case of using liquid hydrocarbons, it has been suggested to spray them to evaporate on the hot catalyst layer so that it evaporates in contact with the catalyst will.

It has also been proposed to vaporize liquid hydrocarbons by using them with Preheated steam are mixed in a heated zone, so that the liquid hydrocarbons substantially completely evaporated and partially before contact with the catalyst be split.

According to one embodiment of the invention, in a step process for obtaining a flammable gas consisting of liquid hydrocarbons and water vapor on part of the cycle the liquid hydrocarbons mixed with water vapor and partially evaporated. The mixture is then passed through a sieve-like evaporator made of hot inert material, which in the essentially completes the hydrocarbon evaporation, and the mixture then through a Catalyst layer at a relatively high temperature sent to a combustible gas and in another part of the cycle heat is added to the sieve evaporator. The presence of the sieve evaporator ensures that practically all liquid hydrocarbons suitably evaporated before the mixture enters the catalyst bed itself in cases where liquid hydrocarbons are directly in contact with the catalyst layer Chamber can be sprayed.

An advantage of this is that the latent heat of evaporation of the liquid hydrocarbons need not be supplied by the hot catalyst layer, so that in the catalyst layer available heat in its entirety can be used to generate that required for the reaction To deliver heat.

The material of the sieve evaporator must be inert and have a high heat capacity and also one have high thermal conductivity, so that as much of the material as possible can withstand temperature changes is subject to during the cycle.

The method is preferably carried out according to a generation and blowing principle, according to which during the generation period of the cycle during which combustible gas is generated in the catalyst sizing, this gas along with undecomposed water vapor after leaving the catalyst layer through a regenerator which removes and stores heat from the gas and water vapor. While During the blowing period, air is heated by being blown through the regenerator and it is hot Air is passed through the catalyst layer and through the sieve evaporator in order to supply heat there.

During the generation period, carbon and heavy carbonaceous residues can occur deposited on the sieve evaporator and catalyst. Burn during the blowing period the carbon and carbonaceous debris in the hot air under development of heat which is at least partially absorbed by the catalyst layer and the sieve evaporator will. During the blowing period, additional air can get between the catalyst layer and be introduced into the sieve evaporator to ensure there is enough oxygen to burn the coal and the carbonaceous residue deposited on the sieve is present. If the heating of the sieve evaporator should be insufficient, a fuel can also between the catalyst layer and the sieve evaporator for combustion with the air will. The residual heat from the sieve evaporator during the blowing period hot gases can be exploited by passing the hot gases through another regenerator which absorbs and stores heat from these hot gases, the Water vapor is passed through this regenerator in the opposite direction during the generation period, so that it overheats therein will.

It is desirable that the flow of water vapor be brief at the end of the generation period Time should continue, either at the same or a different speed, after the supply of liquid hydrocarbons has been turned off to ensure that any volatiles which are in incomplete Way from the deposited hydrocarbons or hydrocarbon residues are formed, removed from the sieve evaporator and other parts of the system and through the Catalyst layer are supported.

The invention also includes suitable equipment for carrying out the process. Thus, no According to the invention, a system for the extraction of a combustible gas from liquid hydrocarbons and water vapor a gasification chamber, in which the volatile hydrocarbons with Steam mixed and partially evaporated, © inen sieve evaporator from hot inert Material through which the mixture is passed and wherein evaporation is essentially complete is, and a hot catalyst layer through which the mixture after passing through passed through the sieve evaporator and in which the conversion of the mixture into a combustible gas is accomplished.

According to one embodiment of the invention, the sieve evaporator has the shape of a grate or Sheep board masonry or the like made of inert heat

solid material and is separated from the inlet end of the catalyst layer. It can be a lockable Air inlet to the space between the sieve evaporator and the catalyst layer be present, through which air during the Time of heating the sieve can be allowed. There can also be a closable fuel inlet to be present in the same space, so that a fuel for the purpose of combustion with the air ίο can be allowed to add extra heat to be provided for the sieve.

According to another form of the invention, the sieve evaporator provides a layer of inert heat-resistant material Material which is placed on top of the catalyst layer.

The invention can be carried out in various ways and according to a particular installation you, a modification of it and the way in which the plant is operated to a To generate flammable gas from liquid hydrocarbons and water vapor is still to be referred to to be described on the drawings which represent in

Fig. Ι a scheme of a system in which the sieve evaporator has the shape of one of the catalyst layer has a separate grate,

Fig. 2 shows a modification, wherein the sieve evaporator is in the form of a layer of inert, heat-resistant material placed on top of the catalyst layer.

The system shown in the drawings works according to the generation and blowing principle. During the generation period, water vapor is supplied to the bottom of a first vessel 10 through a water vapor inlet 11. It goes up through a heat regenerator 12 made of checkerboard masonry, which during the previous blowing period was heated in a manner to be described to a temperature sufficient to superheat the water vapor. The superheated water vapor passes through a throttle 13 into a gasification chamber 14. Liquid hydrocarbons are introduced into the gasification chamber through a supply line 15 and are at least partially vaporized therein. The heat required for evaporation comes from the water vapor and from the walls of the gasification chamber, which were strongly heated during the previous blowing period. The mixture of water vapor and hydrocarbons leaves the first vessel 10 through a connecting line 16 and enters a chamber 17 at the top of a second vessel 18. More liquid hydrocarbons are introduced into the chamber 17 through a supply line 15 '. At the bottom of the chamber 17 there is a sieve evaporator 19 in the form of a grate or checkerboard masonry made of inert, heat-resistant material of relatively high heat capacity and thermal conductivity. The sieve evaporator is hot after it has absorbed and retained heat during the previous blowing period. The evaporation of the liquid hydrocarbons is stopped at the sieve evaporator. As it emerges below the sieve evaporator, the mixture of water vapor and evaporated hydrocarbons passes through a flat space 20 and then enters the catalyst layer 21. The catalyst layer has been heated vigorously during the previous blowing period. Their temperature and that of the mixture of water vapor and hydrocarbons are sufficient to cause the desired reaction between the water vapor and the hydrocarbons to produce a combustible gas, and the heat content of the catalyst layer is sufficient to maintain this endothermic reaction for an economical time . The gas exiting the catalyst layer is still quite hot and it goes through a checkerboard regenerator 22 and, after having given off heat to this regenerator 22, the combustible gas is evacuated through line 23 as required.

During the generation period, carbonaceous Deposits in the gasification chamber 14, the line 16, the chamber 17, the Sieve evaporator 19, the space 20 and the catalyst layer 21 is formed and some volatiles can in an incomplete manner from these deposits especially in the cooler part of the plant. Hence it is in the end of each generation period, it is desirable to complete the supply of liquid hydrocarbons before the water vapor supply is closed, so that the system is volatile with water vapor from all Components is freed.

The water vapor supply is shut off for blowing and the gas evacuation line 23 is closed and air blown into the bottom of the second vessel 18 through a conduit 24 from a blower 25. This air goes up through the regenerator 22, where it absorbs heat. The hot air flows up through the catalyst layer 21 and the sieve evaporator 19 in chamber 17 and then on through line 16 and gas chamber 14, adding heat in all of them these parts by burning any carbonaceous, 'during the previous one Deposits formed during the generation period. Some of the heat generated is in the Catalyst layer from the sieve evaporator, the walls of chambers 17 and 14 and in the duct 16 absorbed and stored. The hot gases then flow down through the regenerator 12, where they give off more of their heat, and are then passed through a line 26 to a heat exchanger (not shown), which helps to generate steam, and then exhausts to the outside air. ; enter.

Additional air can through a line 27 in the space 20 between the sieve evaporator and the Catalyst layer can be introduced to provide additional oxygen, which is necessary for burning carbon deposits on the sieve evaporator may be necessary. Additive-

Lent air can also be used at other points in the system, for example through a duct, if desired 28 and 29 are introduced. Any or all of these additional air lines can be used with Burners 30, 30 'or 30 ", into which a fuel can be introduced to to provide additional heat during the blowing period. The fuel used is expediently but not necessarily the same liquid hydrocarbon used for the Extraction of the combustible gas is used. In this case, the fuel could be through pipes 31 supplied from the main hydrocarbon supply line branch off.

The admission rates of hydrogen and liquid hydrocarbons during the generation period and air, additional air and fuel during the blowing period can be changed to set or adjust the temperatures to different parts of the system. to adapt to different working conditions of the plant.

In a modification shown in FIG. 2, the sieve evaporator is different from that shown in FIG.

s5 divorced. In this case there is the sieve evaporator 32 from a layer of inert, heat-resistant, layer 21 laid on top of the catalyst Material. The space 20 of Fig. 1 and the burner 30 which leads to it are in this modification dispensable.

Claims (10)

PATENT CLAIMS: 1. Step process for the production of a flammable gas from liquid hydrocarbons and water vapor, wherein for part of the cycle the liquid hydrocarbon is with Water vapor mixed and partially evaporated and then passed through a catalyst layer a relatively high temperature to generate a flammable gas is, characterized in that in this part of the cycle (generation period) the Mixture of water vapor and partially evaporated hydrocarbons by a Sieve evaporator made of hot inert material is passed, which is essentially the hydrocarbon evaporation completed before the mixture is passed through the Kätalysatorsch-icht and that in another part of the cycle (heating or blowing period) heat your sieve evaporator is fed. · 2. Step method according to claim 1, wherein worked after a generation and heating period and during the generation period of the cycle in which combustible gas is in the catalyst layer is generated by this gas after leaving the catalyst layer a regenerator is passed which removes heat from the gas and stores it thereby characterized in that during the heating season the air is blown through the regenerator heated and this hot air through the catalyst layer and through the sieve evaporator is directed. 3. The method according to claim 2, characterized in that during the heating period to- ' additional air is introduced between the catalyst layer and the sieve evaporator. 4. The method according to claim 3, characterized in that that during the heating season a fuel is also between the catalyst layer and introduced into the sieve evaporator for combustion with the additional air. 5. The method according to claim 2 or 3, characterized in that at the end of the generation period the flow of water vapor is continued for a while after the supply has been turned off by liquid hydrocarbons. 6. Plant for performing the method according to one of the preceding claims with a gasification chamber, characterized by a sieve evaporator made of hot inert Material between the gasification chamber and the catalyst layer. 7. Plant according to claim 6, characterized in that the sieve evaporator has the shape a grate or checkerboard masonry or the like. Made of inert heat-resistant material and is remote from the inlet end of the catalyst layer. 8. Plant according to claim 7, characterized in that a closable air inlet to the space between the sieve evaporator and the catalyst layer. Q. Plant according to claim 8, characterized in that that a closable fuel inlet to the space between the sieve evaporator and the catalyst layer is present. 10. Plant according to claim 6, characterized in that the sieve evaporator consists of a Layer of an inert, refractory material placed on top of the catalyst layer. Considered publications: Austrian patent specification No. 117 859. 1 sheet of drawings © 609 706/197 10.56 (609 873 4. 57)