DE102013202713A1 - Producing synthesis gas, involves gasifying carbonaceous gasification material with oxygen-containing gasification agent, and introducing hot synthesis gas and water-containing coolant into evaporator and high-temperature heat exchanger - Google Patents

Abstract

Producing synthesis gas using a gasification agent, comprises: (a) gasifying a carbonaceous gasification material with an oxygen-containing gasification agent to obtain synthesis gas; (b) introducing hot synthesis gas and a water-containing coolant into an evaporator and a high-temperature heat exchanger; (c) performing a contactless heat transfer from the hot synthesis gas to the coolant; and (d) passing the superheated coolant through oxygen carrier materials for an oxygen removal from a structure and an oxygenation in the coolant. Producing synthesis gas using a gasification agent, comprises: (a) gasifying a carbonaceous gasification material with an oxygen-containing gasification agent to obtain synthesis gas; (b) introducing hot synthesis gas and a water-containing coolant having a mass flow rate, a temperature and a pressure into an evaporator and a high-temperature heat exchanger; (c) performing a contactless heat transfer from the hot synthesis gas to the coolant by thermal conduction, evaporation and superheating of the coolant; (d) passing the superheated coolant through oxygen carrier materials for an oxygen removal from a structure and an oxygenation in the coolant; and (e) introducing the oxygen-enriched coolant as a gasifying agent in a gasification reactor and repeating the steps (a)-(d). An independent claim is included for an apparatus comprising an oxygen reactor with moldings and/or beds of oxygen carrier materials, which are passed through with a cooling medium, where the oxygen is installed and removed oxygen in its structure, a gasification reactor connected to the oxygen reactor for the gasification of carbonaceous fuel with an oxygen-containing gasifying agent containing water vapor, and a steam generator and high-temperature heat exchanger for evaporating and superheating the water-containing coolant by heat transfer from the hot synthesis gas and with a discharge line for the superheated coolant to the oxygen reactor.

Description

The invention relates to a high-temperature gasification process for the production of synthesis gas with integrated provision of the gasification agent water vapor and oxygen. Suitable gasifiers are carbonaceous fuels, in particular coal or carbon dust, into consideration.

State of the art

In the known processes of gasification, carbonaceous (C-containing) gasification substances with gasification agents containing oxygen or consisting predominantly of oxygen are converted at high temperatures to the actual gasification product raw gas and the gasification residues ash and dust. The choice of the gasification agent or of the gasification mixture is dependent on the gas quality to be achieved in the gasification process. For a H ₂ -rich gas, for example a synthesis gas for methanation, steam is used as a component of the gasification agent.

The starting materials (gasification) are solid fuels (eg lignite, hard coal, wood, peat, biomass, etc.), which are reacted with water vapor and air or oxygen at higher temperatures. Apart from CO and H ₂ , other products such as CO ₂ , methane and higher-boiling hydrocarbons are formed, as well as H ₂ S and COS in coal gasification, which can be removed by additional process steps such as distillation, pressure washing (to remove CO ₂ ). Usually, these steps require a prior cooling of the process gas, where its waste heat can be used elsewhere. Thus, the provision of the gasification agent steam usually takes place by steam generators that are operated externally with external energy.

The oxygen for the gasification process is usually produced in air separation plants. Various methods are used, one approach being cryogenic distillation at very low temperatures (Linde method). These cryogenic processes for oxygen production are associated with a very high demand for electrical energy due to the necessary compaction and cooling (liquefaction) of the air and thus reduce the efficiency of the overall process for which the oxygen is to be provided. The energy requirement depends on the degree of purity of the oxygen to be achieved.

Another group of air separation processes is based on non-cryogenic processes, such as air separation using molecular sieve absorbents via the pressure swing adsorption process or using polymeric membranes. These processes operate at ambient temperature, which is why their energy requirements are much lower than with cryogenic processes. However, these processes require the use of clean and dry air. In addition, the system technology is very expensive, whereby the investment costs for such methods are relatively high.

In the trial phase is still the use of membranes, which are permeable to oxygen but not for nitrogen. These allow the enrichment of oxygen in a gas volume.

The DE 10 2005 025 345 A1 describes a power plant with CO ₂ recycling, wherein in the return circuit of the carbon dioxide, a gas separation membrane for oxygen enrichment of the hot gas is arranged. By enriching the residual gas with oxygen before its return to the combustion chamber, the firing temperature and thus the efficiency of the reactor can be increased. The return cycle of the carbon dioxide and in particular the blower are designed high temperature resistant for temperatures up to 500 ° C. By supplying highly heated residual gas to the gas separation membrane advantageously their efficiency and thereby the efficiency of the overall process is increased.

Also the WO 03/035223 A1 discloses a method for oxygen separation and energy recovery wherein a specific oxygen-conducting membrane is used to separate oxygen from a gas stream. This oxygen is then fed to a superheated and pressurized vapor stream. In the partial condensation of this vapor stream energy is transferred to a process fluid whose boiling point is below the condensation temperature of the vapor. From the boiling process fluid energy is then extracted in the form of drive energy.

With the US 6,173,663 B1 A method for burning coal dust is presented in which the dust is first mixed with an oxygen-enriched gas and this mixture is then ignited. The enrichment of the gas takes place on a membrane with specific conductivity for oxygen ions, at which a second gas stream oxygen is removed.

In the US 5,964,922 A discloses a process for producing a gas stream having defined oxygen and vapor content, wherein oxygen is withdrawn from a heated gas stream at a first side of an oxygen scavenging membrane. On a second side of the membrane is this oxygen is added to a vapor stream to produce a gas stream containing vapor and oxygen. A first part of this mixture is fed directly to an oxygen-consuming process. A second part of the stream is deprived of water by condensation. The oxygen-containing stream thus produced is mixed with the first part of the mixture in order to be able to set the ratio of oxygen to steam in a targeted manner.

The DE 10 2008 010 928 A1 refers to a process for burning carbonaceous materials for energy production, where the combustion takes place in an oxygen-rich atmosphere, which was previously generated by means of an oxygen-separating membrane. In order to increase the efficiency of the membrane, this is arranged in or above the combustion chamber in order to use the process heat. An optimization of the central combustion process is achieved only by providing the additional oxygen. Additional measures for targeted adjustment of the reaction conditions on the membrane are not mentioned in the document.

Also known are processes in which oxygen-binding solids are first loaded in an oxygen-rich atmosphere and release the bound oxygen in a second step to a low-oxygen atmosphere.

That's how it describes AU 2006 2008 24 A1 an apparatus and method for providing an oxygen-enriched and nearly nitrogen-free gas stream for a process with oxygen consumption. In this case, an oxygen-specific reactor of Perowskitmaterialien is first flowed through at temperatures above 300 ° C with air, wherein oxygen is incorporated into the reactor. Subsequently, the oxygen-poor gas product of the central reaction process is passed through the reactor where it is enriched with oxygen. This gas stream is then fed again to the central process, wherein its relative nitrogen content and thus the amount of nitrogen compounds formed in the central process are advantageously reduced. The process should thus enable the provision of heat with recycle of the gas product produced in the central process.

The US 2010/029997 A1 describes a process for the production of synthesis gas by gasification of carbonaceous gasification agents, wherein an oxygen-enriched solid by contacting with a carrier gas increases its oxygen content and the oxygen-enriched carrier gas is then used for gasification of a carbonaceous gasification agent. The resulting synthesis gas is then initially depressurized, whereby an energy withdrawal from the system is possible, and then also fed to the oxygen-enriched solid to catalyze further reactions, eg. From carbon monoxide to carbon dioxide. The reduced solid is then contacted with an air stream to again reach a maximum oxygen content. The use of a heat exchanger is not explicitly described in the document.

In summary, the provision of the gasification agent usually requires a high energy requirement and / or a high apparatus-technical effort and / or extensive measurement and control technology and / or high investment costs.

The object of the invention is to propose a gasification process in which the provision of the gasification agent is integrated and requires no or only low energy or technical equipment additional investments. The process should continue to be easy to control and long-term stability in the implementation.

• a) Vergasung von kohlenstoffhaltigen Vergasungsstoffen zu Syntheserohgas mit einem sauerstoffhaltigen Vergasungsmittel enthaltend Wasserdampf,
• b) Einleiten des heißen Syntheserohgases sowie eines wasserhaltigen Kühlmittels des Massestroms m, der Temperatur T und des Drucks p in einen Verdampfer und Hochtemperatur-Wärmeübertrager,
• c) darin kontaktfreier Wärmeübergang vom heißen Syntheserohgas auf das Kühlmittel durch Wärmeleitung, dadurch Verdampfung und Überhitzung des Kühlmittels,
• d) Über- und/oder Durchleiten des überhitzten Kühlmittels durch Sauerstoffträgermaterialien, Sauerstoffausbau aus deren Gefüge und Sauerstoffanreicherung im Kühlmittel,
• e) Einleitung des sauerstoffangereicherten Kühlmittels als Vergasungsmittel in einen Vergasungsreaktor und Wiederholung der Schritte a) bis d).

According to the invention, the object is achieved by a method for producing synthesis gas with integrated provision of the gasification agent, comprising the process steps

• a) gasification of carbonaceous gasification materials to synthesis gas with an oxygen-containing gasification agent containing water vapor,
• b) introducing the hot synthesis raw gas and a water-containing coolant of the mass flow m, the temperature T and the pressure p into an evaporator and high-temperature heat exchanger,
• c) therein non-contact heat transfer from the hot synthesis gas to the coolant by heat conduction, thereby evaporation and overheating of the coolant,
• d) passing and / or passing the superheated coolant through oxygen carrier materials, oxygen removal from their microstructure and oxygen enrichment in the coolant,
• e) introducing the oxygen-enriched coolant as a gasification agent into a gasification reactor and repeating steps a) to d).

The invention relates to a process for the integrated provision of the gasification agent, comprising water vapor and oxygen, in the production of synthesis gas by gasification of carbonaceous gasification materials to synthesis gas. In the gasification of carbonaceous gasification hot synthesis gas is produced at temperatures of about 800 ° C, preferably above 900 ° C, more preferably above 1000 ° C. According to the invention this occurs over a Crude gas from the gasification reactor and is introduced into a steam generator and high-temperature heat exchanger.

In the steam generator, a water-containing coolant of the mass flow m, the temperature T and the pressure p is further introduced. In the steam generator, the coolant, preferably water, evaporated by heat transfer from the raw gas, without coming into direct contact with them. The heat transfer preferably takes place by means of heat conduction to boundary layers formed by the evaporator and high-temperature heat exchanger. In the high-temperature heat exchanger then takes place by further contact-free heat transfer overheating of the cooling medium. The evaporation and overheating can take place both in one stage, in one process stage, or in two stages.

Subsequently, the superheated coolant, in particular water vapor, passed over or through moldings or beds of oxygen carrier materials, which can put oxygen in their structure and expand. The oxygen carrier materials are preferably in an oxygen reactor. The oxygen input and output is a temperature-dependent process, wherein the oxygen removal takes place at material-dependent, elevated temperatures, preferably at temperatures above 300 ° C, more preferably above 500 ° C. The temperatures necessary for the oxygen expansion are set in the oxygen carrier materials according to the invention by heat transfer from the superheated refrigerant. Since coolant and oxygen carrier materials are in direct contact, heat conduction, convection and thermal radiation can contribute to this heat transfer. Due to the elevated temperatures, the oxygen carrier materials expand oxygen from their microstructure and accumulate it in the flowing coolant.

Thus enriched leaves the coolant, especially water vapor, the oxygen carrier materials and is introduced as a gasification agent in the gasification reactor, where it reacts with carbonaceous gasification materials and these are in turn converted to synthesis gas. In the context of this description of the invention, the coolant is thus preferably a water-containing solution which absorbs enthalpy from the hot raw gas. By the combination of the coolant of the mass flow m and the oxygen removed from the oxygen carrier materials with the mass flow m _O2 , the gasification agent for the gasification process is formed.

By repeating these process steps results in a gasification process with integrated provision of the gasification agent, wherein advantageously the heat of the raw gas for producing a gasification agent containing water vapor and oxygen, is available. The use of steam as a gasification agent can advantageously ensure an autothermal performance of the process and a high hydrogen content of the synthesis product.

Thus, there are advantageously no additional energy costs for the provision of the gaseous gasification agent, since the residual heat of the hot synthesis gas is advantageously used to evaporate and overheat a water-containing coolant and to remove oxygen from a functional ceramic. It should be noted that the raw gas before its further processing, for example. By gas reforming, Fischer drip synthesis, etc., would have to be cooled anyway.

Further advantageous, the gasification process according to the invention with integrated provision of the gasification agent can be driven almost autonomously, since only a few process and operating parameters have to be set as controlled variables in order to ensure a constant gasification process.

Particularly preferably, the operating parameters of the supplied coolant, in particular temperature T, pressure p and mass flow m, selected or fixed at the inlet to the evaporator, that are set with the cooling of the fuel gas and the Enthalpieaufnahme in this exactly the parameters which for the gasification process are needed. Above all, the temperature, the pressure, the mass flow and the H ₂ O / O ₂ ratio in the gasification agent are decisive for the degree of conversion in the gasification process.

The most important control variable is thus the mass flow m of coolant supplied to the overall process, in particular water, which is adapted to the stream of gasification substances m 'constantly supplied in the gasification process and is maintained during evaporation, superheating and oxygen enrichment. Whether and to what extent corrosion of the ceramic materials in the heat exchanger and oxygen reactor by the coolant has not yet been conclusively clarified, but the influence on the coolant mass flow would be marginal.

The temperature T of the supplied coolant is selected so that by means of the heat absorbed by the raw gas and without additional energy supply oxygen is removed from the structure of the oxygen carrier material and enriched in the coolant. It should be noted that the gasification process and thus the temperature of the raw synthesis gas due to the inhomogeneity of the organic gasification materials Are subject to fluctuations. Furthermore, it should be noted that the subsequent heat transfer from the coolant, in particular water vapor, to the fixed bed bed causes a cooling of the steam flow. The outlet parameters of the water vapor from the high-temperature heat exchanger are therefore preferably adjusted so that it does not fall below its condensation point in the subsequent process steps, in particular when flowing over or through the oxygen carrier material with the coolant, in particular water vapor. The coolant, in particular water vapor, should thus be overheated at the outlet of the O ₂ reactor or at least present as saturated steam.

When the gasification process is under pressure, the gasification pressure or the pressure p 'of the gasifying agent necessary for the gasification is another target value. The pressure of the coolant when introduced into the evaporator p is thus adjusted taking into account the pressure losses at the evaporator, heat exchanger, oxygen reactor and other internals, such as pipelines, etc., that the refrigerant in the gasification reactor or in the gasification agent is present at a partial pressure, the corresponds to the pressure required for the gasification process p '.

Advantageously, the setting of the operating parameters pressure p, temperature T and mass flow m of the coolant during the feed can thus advantageously ensure that the stream of coolant and oxygen removed in the reduction cycle leaves the oxygen carrier material in its composition, in particular in its oxygen / water vapor ratio which corresponds to gasification agent for the thermochemical conversion of solid fuels in the gasification reactor.

The oxygen content of the gasification agent after enrichment is determined in the process according to the invention in particular by the operating parameters of the coolant present in the perovskite reactor. The oxygen removal is dependent on the temperature of the oxygen carrier, which is set by the temperature of the superheated coolant flow. The heating of the functional ceramic is a transient process, whereby the temperature increases as a function of time and thus also varies the oxygen expansion.

Therefore, in a preferred embodiment of the method according to the invention after the oxygen enrichment, the supply of an oxygen-containing gas stream to the gasification agent is provided to compensate for any fluctuations in the H ₂ O / O ₂ ratio and to guarantee the oxygen concentration necessary for the gasification. Furthermore, can be kept constant by supplying an oxygen-containing gas stream with the mass flow m _'O2, the sum of the gasifying agent constituent mass flows m, m _O2 and m' _O2 advantageous in the gasification reactor. This can be compensated in particular fluctuations or Anfahrverläufe the oxygen removal from the oxygen carrier materials. Also preferably, after oxygen enrichment, another heat exchanger is provided to selectively cool or heat the gasification agent prior to gasification to ensure optimum gasification conditions. Further preferably, the gasification agent carbon dioxide can be buried that, apart from a possible conversion to carbon monoxide in a Boudouard reaction during gasification remains largely inert, and thus advantageously allows a detached from the stoichiometric adjustment of the pressure conditions of the gasification agent.

The moldings or beds of oxygen carrier materials are preferably regenerated between the repetitions of gasification, evaporation and overheating and oxygen removal by a gas or gas mixture containing oxygen flows over or through them and thereby new oxygen is incorporated into the structure. The oxygen incorporation and the oxygen removal from the functional ceramics used in the method according to the invention are temperature-dependent processes, the optimum temperature ranges depending on the specific choice of the oxygen carrier material.

In order to ensure the most autarchic overall process, in a preferred embodiment of the process according to the invention, at least two shaped bodies or beds of oxygen carrier materials are alternately overflowed or flowed through with cooling medium and an oxygen-enriched gas, an oxygen-enriched gas mixture or air. This advantageously enables the regeneration of one functional ceramic, while the other provides oxygen for the gasification process. The two shaped bodies or beds of the oxygen carrier materials may be located in two different oxygen reactors or may be arranged together in an oxygen reactor. In the latter case, however, the moldings or beds are preferably separated from each other gas-tight and provided with their own supply and discharge lines.

For the provision of oxygen, the setting of certain operating conditions in the functional ceramic is essential. In particular, elevated temperatures are necessary for the oxygen removal, which are realized by passing the superheated coolant emerging from the heat exchanger into the oxygen carrier material. There, the vapor stream is enriched with oxygen and then fed to the gasification process. Also preferred is an additional heating of the oxygen reactor by means of a heat transfer from the hot synthesis gas.

The expansion of oxygen in the oxygen carrier materials, preferably perovskites or perovskite compounds, is carried out at elevated temperatures> 500 ° C, preferably> 300 ° C and until a certain, material-dependent minimum oxygen concentration is reached. Then a regeneration of the oxygen carrier material is necessary, which can be achieved at lower temperatures below 500 ° C, preferably below 300 ° C, by circulating or flowing through with a gas or gas mixture containing air.

According to the invention, at least one perovskite system in the loaded state is always available. Advantageously, the oxygen incorporation is faster than the oxygen expansion, so that for the overall process already two oxygen storage for a continuous process management are sufficient. The required temperature for oxygen incorporation for the regeneration of the oxygen carrier materials is advantageously achieved by the precise adjustment of the supplied air mass flow. An excessive cooling of the functional ceramic by the overflow with the oxygen-containing stream should, however, be avoided in order to keep the energy costs of the overall process as low as possible and to avoid a condensation point undershooting in the vapor stream. Keeping a certain temperature range in the bed is thus advantageous for the cycle of oxygen incorporation and can also be realized by means of the heat stored in the process gas.

A certain minimum temperature is thus advantageous for increased oxygen incorporation. On the other hand, temperatures that are too high would activate the expansion of oxygen, in that the oxygen partial pressure in the oxygen carrier materials would be higher than in the atmosphere. If the temperatures for an expansion of oxygen, ie temperatures> 300 ° C, preferably> 500 ° C, are reached, then adjusts itself at the phase boundary and it comes to a standstill Sauerstoffein- and -ausbaus. Essential for an efficient process of oxygen incorporation is thus the setting of a temperature in oxygen carrier materials in a fixed range. This can preferably be realized in the industrial application with the aid of an external temperature control. Temperatures between 100 ° C and 600 ° C, preferably between 150 ° C and 400 ° C and more preferably between 250 ° C and 300 ° C are particularly preferably set in the bed.

contraption

The object of the invention is further achieved by a device for producing synthesis gas with integrated provision of a gasification agent containing water vapor and oxygen, comprising an oxygen reactor, with moldings and / or beds of oxygen carrier materials which can be overflowed or flowed through with a cooling medium and oxygen in it Assemble and disassemble structure, connected to the oxygen reactor gasification reactor for gasification of carbonaceous fuels with an oxygen-containing gasification agent containing water vapor and a subsequent to the withdrawal of the gasification reactor steam generator and high-temperature heat exchanger for evaporation and overheating of a water-containing coolant by heat transfer from the hot synthesis gas and with a discharge for the superheated refrigerant to the oxygen reactor.

According to the invention, the oxygen reactor, the gasifier and the steam generator and high-temperature heat exchanger form a functional unit which provides the gasification agent necessary for the gasification process or the energy necessary for the provision of the gasification agent

In this functional unit, the synthesis gas produced in a gasification process at a very high temperature is fed via a deduction in the gasification reactor space to a steam generator and high-temperature heat exchanger. In the steam generator, a coolant, preferably an H ₂ -rich coolant, more preferably water, an aqueous solution or water vapor, is vaporized by heat transfer from the hot raw gas to the coolant and thus cooled the synthesis gas. If the coolant is largely or completely water, saturated steam is preferably generated in the steam generator. In the high-temperature heat exchanger, there is again a heat transfer from hot raw gas to the already evaporated coolant, whereby the coolant vapor is overheated.

The high-temperature heat exchanger can be designed in different designs, preferably as a tube bundle heat exchanger or heat pipe (heat pipe) heat exchanger. The use of various energy sources for the thermochemical conversion by gasification creates atmospheres that provide the conditions for coupling heat flows but are very material-hostile for the previously used metallic heat exchangers. These are therefore unstable against the high temperatures and corrosion. But in energy technology just high temperatures have a better energetic Favoring efficiency, ceramic materials are preferred for the heat exchanger, which have a higher temperature and corrosion resistance than steels.

In a preferred embodiment, evaporator and high-temperature heat exchanger are designed as a functional unit, so that the evaporation and overheating takes place in one stage in a module. In a particularly preferred embodiment, the evaporation and overheating of the water takes place in two stages, so that only the superheater must be designed as a high-temperature heat exchanger. This allows a structurally simple solution of the evaporator while saving high-temperature resistant materials that are needed only for the heat exchanger.

Subsequently, the superheated cooling medium, preferably water vapor, fed from the heat exchanger via a feed line to the oxygen reactor. This contains shaped bodies or beds of oxygen carrier materials which are passed through or overflowed with the coolant vapor. According to the invention, the oxygen carrier materials are able to incorporate and remove oxygen from their microstructure, oxygen being removed at elevated temperatures. Depending on the design of the device according to the invention and the type of oxygen carrier material used, moldings and / or fillings can be used. The oxygen carrier materials preferably have an enlarged surface, which can be achieved, for example, by high porosity in the case of shaped bodies or small grain sizes in the case of beds.

The oxygen-enriched coolant vapor, preferably water vapor, is then fed via a feed line to the gasification reactor chamber as gasification agent for the gasification of carbonaceous gasification substances to synthesis gas.

Depending on the capacity of the oxygen carrier materials in terms of the amount of oxygen bound, the operating time of the functional unit for providing the gasification agent is limited. Upon reaching a minimum amount of oxygen in the material, regeneration of the oxidizer becomes necessary. The incorporation of oxygen into the structure of the carrier material takes place in the air stream. Preferably, with the aid of a blower, an oxygen-rich gas or gas mixture, more preferably ambient air, is passed over or through the shaped bodies or the charge.

In a likewise preferred embodiment of the device according to the invention, at least two shaped bodies or beds of oxygen carrier materials are provided in the oxygen reactor, which can be overflowed or flowed through alternately with the cooling medium, preferably water vapor, and an oxygen-rich gas or gas mixture. Thus, the regeneration of one of the moldings or beds is carried out while at the other a cooling medium, preferably water vapor, is enriched with oxygen. For reciprocal operation of the steam generator and heat exchanger, the two gas-tight separate amounts of oxygen carrier materials and the gasification reactor space are provided with mutually switchable leads. Thus, with respect to the steam generator and heat exchanger and the gasification reactor continuous operation can be ensured in which the steam generator and heat exchanger continuously with coolant, preferably water or steam, and the gasifier is continuously fed with oxygen-enriched coolant as a gasification agent, in particular oxygen-enriched water vapor.

According to the invention, the shaped bodies or beds are formed from oxygen carrier materials which are functionally capable of incorporating and expanding oxygen under defined operating conditions. Preferred oxygen carrier materials are perovskites or perovskite compounds of the ABO3-δ type with A = La, Ba, Sr and / or Ca; B = Ti, Cr, Mn, Fe, Co, Ni, Al, Zr, Nb, Al, Sn and / or Ce). Perovskites or the perovskite compounds are functional ceramics, which at elevated temperatures> 300 ° C., preferably> 500 ° C., expand oxygen from the microstructure and, apart from this, are very thermally stable.

Particular preference is given to using perovskite compounds as the oxygen storage material, selected from Ca 0.5 Sr 0.5 Fe 0.5 Nn 0.5 O3-5; Ca0.5Sr0.5Fe0.2Mn0.8O3-5; Ca0.5Sr0.5Fe0.5Mn0.5O3-δ; Sr3Fe2O6 + δ; Sr2.25 Ca0.75 Fe2 O6 + δ, Sr1.5 Ca1.5 Fe2 O6 + δ; Sr0.75Ca2.25Fe2O6 + δ; or Ca 3 Fe 2 O 6 + δ.

In order to prevent excessive cooling of the water vapor on the oxygen carrier materials and to facilitate the achievement of the temperatures necessary for the expansion of the oxygen, the shaped bodies or beds of oxygen carrier materials are preferably provided with an additional tempering device.

With regard to oxygen incorporation, it is essential that a temperature range in the bed is recorded. Oxygen incorporation into the perovskite is only possible at low temperatures below 500 ° C., preferably below 300 ° C., since at too high temperatures the competing process of oxygen expansion would be activated. At the same time, too much cooling of the oxygen reactor should be avoided in order to avoid the energetic To keep costs of the subsequent oxygen expansion low.

The tempering device, which advantageously serves to adjust the temperature during oxygen introduction and removal, is preferably designed as a heat exchanger in which heat is withdrawn from the hot synthesis crude gas. Particularly preferably, the oxygen reactor is double-walled and designed with switchable valves for the passage of hot synthesis gas through the wall. A fine adjustment of the temperature takes place by mixing with ambient air.

Furthermore, the device according to the invention preferably has measuring devices with which the oxygen concentration of the cooling or gasifying agent after the oxygen enrichment can be determined. Thus, the oxygen enrichment actually carried out can be advantageously determined on the basis of the temperature-dependent oxygen expansion from the oxygen carrier materials. If appropriate, the oxygen concentration required for the gasification process can then be readjusted, for example by supplying a separate oxygen-containing gas stream. Also preferred is a measuring device for the pressure of the gasification agent and means for supplying carbon dioxide.

Further preferably, between the moldings or beds of oxygen carrier materials and the gasification reactor, a measuring device for determining the temperature of the gasification agent and particularly preferably a further heat exchanger is provided. This is used, as needed, the cooling or heating of the gasification agent before gasification. Thus, it is advantageously possible to achieve a high temperature of the coolant in the perovskite system and thus a high oxygen expansion, and then to reduce the temperature to values suitable for the gasification.

The invention likewise relates to the use of a synthesis gas produced by gasification of carbonaceous gasification substances, in particular the heat or exergy stored therein, for evaporating and overheating a cooling medium and for removing oxygen from the structure of a shaped body or beds of oxygen carrier materials.

An essential feature of the invention is the provision of oxygen as a gasification agent for the gasification process of solid fuels using process-internal heat in a sub-system, which apparatus and control technology requires no major expense. The efficiency of the overall process is greatly increased by this process combination. The process management is almost self-sufficient. With the use of perovskites and the use of water vapor generated in the combustion gas cooling as a heat transfer medium for the activation of oxygen removal from the perovskites a self-contained system is created, which is not yet used in this way.

embodiment

Based on the following illustrations, embodiments of the invention will be explained in more detail. Showing:

1 a circuit diagram of a preferred embodiment of the method according to the invention for the production of synthesis gas with integrated provision of the gasification agent and one-stage evaporation and superheating,

2 a circuit diagram of a preferred embodiment of the method according to the invention for the production of synthesis gas with integrated provision of the gasification agent and two-stage evaporation and superheating,

3 Representation of sample mass, sample temperature and system pressure measured during a thermogravimetric process during oxygen incorporation into a perovskite sample.

4 Representation of sample mass, sample temperature and system pressure measurements during oxygen build-up in a perovskite sample determined in a thermogravimetric method.

According to the in 1 shown block diagram is a carburetor 1 in operative connection with a steam generator and high-temperature heat exchanger 2 and a functional ceramic unit 3 ,

For the oxygen supply is a bed 3.1 consisting of perovskites loaded with oxygen, arranged in a fixed bed reactor, with according to the process pressure in the gasifier 1 superheated steam overflows, allowing a condensation of water vapor in the bed 3.1 can be excluded. The oxygen is released from the bed according to the temperatures in the reactor 3.1 expanded, attached to the steam and leaves it in a mixture with the water vapor. This mixture can then be used directly or with the addition of further oxygen, in the gasification process, which is supplied to a constant stream of gasification agent, as a gasification agent. The mass flow of water vapor in the high-temperature heat exchanger 2 is generated, is constant and depends on the required water vapor mass flow as part of the gasification agent.

The gasification process can be carried out in a fixed bed reactor 1 or a fluidized bed reactor 1 will be realized. In the gasification process, a synthesis gas is generated, which must be cooled before its further use, for example in a synthesis. The physical heat of the synthesis gas is then used to generate water vapor and its overheating, which is used as a carrier gas for the oxygen supply. Depending on the gasification process, in particular on the quality of the gasification substances, the quality and quantity of the raw gas can vary. For the process circuit described here, essentially the mass flow and the temperature of the raw gas are decisive. Since the mass flow of water vapor is a fixed process variable, the temperature of the water vapor upon entry into the Perowskitfestbettreaktor 3 vary.

In the carburetor 1 Become solid C-containing fuels with oxygen and water vapor thermochemically at high temperatures and in the pressure mode (about 30 bar) in a raw gas, which is to be used after its preparation as synthesis gas. The corresponding entry temperature into the synthesis is in a high-temperature heat exchanger 2 set downstream heat exchanger. As a cooling medium, for example, air can be used here. The amount of cooling air depends on the inlet temperature of the raw gas, which, due to the constant water vapor mass flow in the high-temperature heat exchanger 2 , varies.

According to the in 2 shown block diagram is a carburetor 1 in operative connection with a steam generator 2.1 and high-temperature heat exchangers 2.2 and two beds of a functional ceramic unit 3 ,

In the implementation of the method according to the invention according to 2 will that in a carburetor 1 produced raw gas with a temperature of 920 ° C, a pressure of 30 bar and a mass flow of 284 kg / MWh initially on a ceramic high-temperature heat exchanger 2.2 guided, where it transfers its physical energy to a previously in a steam generator 2.1 saturated steam generated at a temperature of 246 ° C, which converts the saturated steam to that for the oxygen uptake in the perovskite reactor 3.1 required parameters, in particular to a temperature of 500 ° C, a pressure of 37 bar and a mass flow of 86 kg / MWh, is overheated.

The cooled to 842 ° C raw gas then leaves the high-temperature heat exchanger 2.2 and flows through the steam generator 2.1 by transferring its heat to water, that of the steam generator 2.1 with a temperature of 20 ° C, a pressure of 37bar and a mass flow of 86 kg / MWh is supplied. As a result, the raw gas cools to 496 ° C and must be in an in 2 not shown further heat exchangers are cooled to synthesis entry conditions.

The structural design of the heat exchanger 2.2 can be done in different versions (tube bundle, heat pipe). In the heat exchanger 2.2 the cooling medium is superheated under pressure conditions corresponding to the required inlet pressure of the gasifying agent into the gasifier 1 guarantee. It must be the pressure losses of the heat exchanger 2.2 , fixed bed perovskite reactor 3 and the plant components used, such as pipes, bends, tees, fittings, etc., are taken into account. To compensate for these losses, which vary depending on the output size and process structure, is the admission pressure of the cooling medium at the steam generator 2.1 adjust accordingly.

Overheating in the heat exchanger 2.2 must in any case be done so far that it in the subsequent functional ceramic unit 3.1 does not come to the condensation of water vapor with the perovskite for the O ₂ supply. At temperatures> 300 ° C, the functional ceramic becomes 3.1 O ₂ expanded and in the carrier medium water vapor from the reactor 3 discharged and the mixture of a mass flow of oxygen at 68 kg / MWh and a mass flow of water vapor at 86 kg / MWh as a gasifying agent to the carburetor 1 fed.

In 3 and 4 The results of laboratory investigations were carried out by means of thermo-gravimetric analysis (TGA), in which a defined amount of sample was steam-bathed under a pressure of 37 bar and heated. The mass loss (Δm = f (θ, t)) occurring during the oxygen evolution was recorded and is in 3 shown. In 4 The measurements of the mass increases (Δm = f (θ, t)) of the perovskite during oxygen incorporation are shown. For this purpose, the perovskite was overflowed in the TGA under pressure reduction with air and recorded the resulting increase in mass.

As in 3 As shown, an oxygen-saturated perovskite mass of 3.1304 g was subjected to a thermo-gravimetric analysis. The system pressure was initially raised to 18.5 bar in an argon atmosphere. Target parameters were 37 bar, which can only be reached after a very long time without heating. The sample and system were then heated under argon at a heating rate of 20 K / min to a temperature of 246 ° C. This temperature corresponds to the Boiling temperature of water vapor at 37 bar. The pressure build-up takes place much faster with increasing temperature in the system. The temperature was raised further to 330 ° C before the addition of steam, so as to exclude condensation phenomena to 100%. Upon reaching this temperature, the atmosphere was switched from argon to steam. In the TGA, the mass of the sample is recorded as a function of temperature, pressure and time. In the process of oxygen expansion, the mass of the specimen will be expected to become smaller.

In 3 For example, two functions are shown for the sample mass, one being the measured mass and the other being the corrected mass. The correction of the measured values of the sample mass is necessary because a force acts on the sample body as a result of the overpressure and the temperature change in the system. For the analysis of the oxygen expansion, only the corrected sample mass is considered.

The first in 3 The decrease in the corrected mass associated with the increase in the system temperature is solely due to the changes in the conditions in the TGA. Increasing the temperature helps build up pressure in the system. In addition to the volume of the overflowed body, the fluid density of the circulating medium is included in the correction calculation of the sample mass. As the temperature increases, the density of argon decreases, increasing with increasing pressure. The superposition of these effects gives the in 3 shown. Functional course of the measured sample mass.

A decrease in mass due to oxygen evolution is evident in both functions, the measured and the corrected sample mass. The oxygen expansion is activated from a temperature of 250 ° C. For the quantitative evaluation of the process, an equation for the oxygen expansion rate is determined in evaluation of the function, which provides a basis for the design of the process of providing oxygen and thus allows a statement about the addition in the process, specifically in the gasification agent to be supplied amount of oxygen ,

In 4 is a TGA evaluation of the process of regeneration of the perovskite, ie the process of loading with oxygen, shown. For this process, the system was relaxed and turned off the heating. The sample body was overflowed with an argon / oxygen mixture with an Ar / O ₂ ratio of 3.7: 1. Oxygen incorporation is characterized by an increase in mass of the sample.

As in 4 to recognize immediately takes place an increase in mass. Since the oxygen partial pressure in the atmosphere is much higher than in the perovskite, where it is almost zero when fully discharged, the vacancies in the perovskite are immediately enriched with oxygen. In evaluation of the function, an equation for the reaction rate of oxygen incorporation is derived.

From 3 and 4 derivable reaction rate equations provide information on possible implementations of the overall process, in particular how many reactors have to be integrated into the system. For the provision of oxygen, a perovskite system in the loaded state must be available at all times. Since the process of oxygen incorporation is the faster process, the process can be advantageously carried out already with two reactors. Since there are more degrees of freedom in the process of regeneration with respect to the media streams, in particular the air stream, this sub-process can be easily influenced. For example, can be adjusted by the targeted adjustment of the air mass flow, the required minimum temperature for the oxygen installation.

LIST OF REFERENCE NUMBERS

1

carburettor

2

High-temperature heat exchanger

2.1

steam generator

2.2

High-temperature heat exchanger

3

Festbettperowskitreaktor

3.1

Perwoskitschüttung in endothermic operation

3.2

Perovskite in exothermic operation

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102005025345 A1 [0007]
• WO 03/035223 A1 [0008]
• US 6173663 B1 [0009]
• US 5964922A [0010]
• DE 102008010928 A1 [0011]
• AU 2006200824 A1 [0013]
• US 2010/029997 A1 [0014]

Claims (14)

Process for the production of synthesis gas with integrated provision of the gasification agent, comprising the process steps a) gasification of carbonaceous gasification substances with oxygen-containing gasification agent to synthesis gas, b) introducing the hot synthesis raw gas and a water-containing coolant of the mass flow m, the temperature T and the pressure p into an evaporator and high-temperature heat exchanger, c) contact-free heat transfer from the hot synthesis gas to the coolant by heat conduction, thereby evaporation and overheating of the coolant, d) passing and / or passing the superheated coolant through oxygen carrier materials, oxygen removal from their microstructure and oxygen enrichment in the coolant, e) introducing the oxygen-enriched coolant as a gasification agent into a gasification reactor and repeating steps a) to d). A method according to claim 1, characterized in that the mass flow m according to the gasification supplied mass flow of the gasification material m 'and / or the pressure p are set according to the gasification pressure p'. Method according to one of claims 1 and 2, characterized in that the temperature T is adjusted so that in steps c) to e) falls below the condensation point of the coolant is avoided. Method according to one of the preceding claims, characterized in that after passing over and / or passing through the oxygen carrier materials, the gasification agent is additionally enriched with oxygen and / or tempered. Method according to one of the preceding claims, characterized in that the oxygen carrier materials between the repetitions of steps a) to e) with a gas or gas mixture containing oxygen and / or flowed through and thereby oxygen is incorporated into their structure. Method according to one of the preceding claims, characterized in that at least two shaped bodies or beds of oxygen carrier materials alternately with superheated cooling medium and a gas or gas mixture containing oxygen flows and / or flows through and the steps a) to e) are repeated continuously. Method according to one of the preceding claims, characterized in that the oxygen carrier materials are tempered by means of heat transfer indirectly from the hot synthesis gas. Apparatus for generating synthesis gas with integrated provision of a gasification agent, comprising An oxygen reactor, with shaped bodies and / or beds of oxygen carrier materials which can be overflowed or flowed through with a cooling medium and can incorporate and expand oxygen into their structure, - A connected to the oxygen reactor gasification reactor for the gasification of carbonaceous fuels with an oxygen-containing gasification agent containing water vapor and - A subsequent to the departure of the gasification reactor steam generator and high-temperature heat exchanger for evaporation and overheating of a water-containing coolant by heat transfer from the hot synthesis gas and with a derivative of the superheated refrigerant to the oxygen reactor. Apparatus according to claim 8, characterized in that at least two oxygen reactors are connected to the gasification reactor and the high-temperature heat exchanger, which are alternately over-flowable with coolant or gas or gas mixture containing oxygen or flowed through. Device according to one of claims 8 and 9, characterized in that the oxygen reactors additionally have a tempering device. Device according to one of claims 8 to 10, characterized in that between oxygen reactor and gasification reactor sensors for measuring temperature and oxygen concentration of the gasification agent and / or a heat exchanger and / or means for admixing oxygen are arranged. Device according to one of claims 8 to 11, characterized in that the oxygen carrier materials from Perwoskiten or perovskite compounds selected from Ca0.5Sr0.5Fe0.5Mn0.5O3-5, Ca0.5Sr0.5Fe0.2Mn0.8O3-5, Ca0 .5Sr0.5Fe0.5Mn0.5O3-δ, Sr3Fe2O6 + δ, Sr2.25Ca0.75Fe2O6 + δ, Sr1.5Ca1.5Fe2O6 + δ, Sr0.75Ca2.25Fe2O6 + δ or Ca3Fe2O6 + δ. Device according to one of the preceding claims 8 to 12, characterized in that the high-temperature heat exchanger is formed of ceramic materials. Use of the exergy of a syngas produced by gasification of carbonaceous gasification materials for vaporizing and overheating a cooling medium containing water and for the removal of oxygen from the structure of oxygen carrier materials.

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