How enriched combustion using solid electrolyte ionic conductor systems

 

(57) Abstract:

The invention relates to the unification of methods of combustion, enhanced oxygen and the separation of oxygen using a solid electrolyte ion conducting membranes. How is that split the flow of the injected gas containing elemental oxygen, oxygen-enriched gas stream and the oxygen-depleted gas stream, in which oxygen-enriched gas stream is used in the combustion chamber, thus carry out the compression of the supplied gas stream, separating the oxygen from the compressed gas stream using an ion transport module, with purified oxygen gas stream is mixed with other gas components on the penetrating side with the formation of oxygen-enriched gas stream, the purge penetrating side of the ion transport membrane at least part of the gas flow of the combustion products, obtained from the combustion in the combustion chamber of a gas stream leaving pronicheva side of the ion transport module. The invention allows to increase economic efficiency, to reduce the emission of harmful substances into the environment after the combustion process. 9 C.p. f-crystals, 4 Il., 3 table.

Up to the present time to separate the desired gases from air and other gas mixtures used many different systems oxygen separation, for example organic polymeric membrane systems. Air is a mixture of gases, which may contain different amounts of water vapor, and sea level this mixture has approximately the following composition (by volume): oxygen (20.9 percent), nitrogen (78%), argon (0,94%) and the balance consisting of traces of other gases. A completely different type of membrane can, however, get some inorganic oxides. Such solid electrolyte membrane is produced from inorganic oxides, typical examples of which are calcium - or yttrium-stabilized Zirconia or similar oxides having the structure of fluorite or perovskite.

Some of these solid oxides have the ability to conduct oxygen ions at high temperatures, when an electric potential is applied across the membrane, thus they are only electrically driven or IITI oxygen ions under conditions of elevated temperatures during the application of the chemical potential. Such is driven by the pressure of the conductors ion and mixed conductors can be used as membranes for the extraction of oxygen from the oxygen-containing gas flows, if accompanied by sufficient partial pressure of oxygen to provide leading chemical potential. Since the selectivity of these materials in relation to oxygen is unconstrained and can be obtained fluxes of oxygen, usually by several orders of magnitude greater than for conventional membranes, created attractive opportunities for obtaining oxygen by use of such ion transport membranes.

Although the potential for such an oxide ceramic materials, such as gas separation membranes, great, there are some problems associated with their use. The most obvious difficulty is that all the known oxide ceramic materials demonstrate appreciable ionic conductivity only at high temperatures. Usually for their good work desired temperature considerably above 500oC, usually in the range of 600-900oC. These restrictions remain, despite numerous studies to find materials that work well at low the HT USA N 5547494, entitled Staged Electrolyte Membrane included in this description by reference for a more complete description of current level of technology.

Combustion processes, however, typically operate at high temperatures, therefore there is the potential for efficient integration of ion transport systems with enhanced oxygen combustion processes, and the present invention includes new integration schemes ion transport systems and combustion processes, reinforced by oxygen.

The most traditional combustion processes use the most convenient and widely used source of oxygen, namely, air. Present in air, nitrogen does not contribute to the combustion process and, Vice versa, can create many problems. For example, nitrogen at temperatures of combustion reacts with oxygen, forming oxides of nitrogen (NOx), which are undesirable polluting products. In many cases, the combustion products must be processed to reduce emissions of nitrogen oxides below environmentally acceptable levels. In addition, the presence of nitrogen increases the volume of flue gas, which in turn increases heat losses in the flue gas and reduces thermal efficiency of the combustion process. For Soderini (ACS). Oxygen-enriched combustion provides several benefits, including reduced emissions (in particular, nitrogen oxides), improved energy efficiency, reduced volume of flue gas, a cleaner and more stable combustion and the possibility of increased thermodynamic efficiency in cycles flow. However, these advantages ACS must match a value of the oxygen, the production of which is necessary for these purposes. Therefore, the market for ACS largely depends on the cost of obtaining oxygen-enriched gas. It has been estimated that for new markets ACS will require approximately 100,000 tonnes of oxygen per day, if the cost of the oxygen-enriched gas will be reduced to approximately $ 15 per ton. It turns out that the processes of gas separation using ion-transport membranes are promising in light of this goal. ACS is described in detail in H. Kobayashi Oxygen Enriched Combustion System Performance Study, Vol. 1: Technical and Economic Analysis (Report N DOE/1D/12597), 1986, Vol. 2: Market Assessment Report N DOE/1D/12597-3), 1987, Union Carbide Company-Linde Division, Reports for the U. S. Dept. of Energy, Washington, D. C.).

The literature on the technology of ion-transport guides for use for separation of oxygen from a gas stream includes:

Kang et al., U.S. patent N 5516359, entitled Integrated High Temperature Method for Oxygen Production, relates to a method for providing oxygen from the heated and compressed air using a solid electrolyte ion conducting membranes, in which the sealed product is again heated and passed through a turbine to generate power.

Mazanec et al., U.S. patent N 5160713, entitled Process for Separating Oxyden from an Oxyden-Containing Gas by Using a Bi-containing Mixed Metal Oxide Membrane, reveals containing bismuth materials that can be used as a conductor of oxygen ions.

Publications related to oxygen-enriched or enhanced combustion (ACS) include the above-mentioned reports of the U.S. Department of Energy authors H. Kobayashi and H. Kobayashi, J. G. Boyle, J. G. Keller, J. B. Patton, and R. C. Jain, Technical and Economic Evaluation of Oxygen Enriched Combustion Systems for Industrial Furnace Applications, what are the various technical and economic aspects of enhanced oxygen of combustion systems.

Oxygen-enriched combustion is a commercial process that uses oxygen, which is produced either by way of cryogenic distillation, or non-cryogenic means, such as adsorption when the differential pressure (pressure swing adsorption (PSA)). All of these processes operate at temperatures below 100oC and so they are difficult to thermally combined with combustion processes.

Research in the field of solid electrolyte ionic conductors have been performed for many years. The solid electrolytes used in fuel cells and sensors, as well as for experimental receive small amounts of pure oxygen from the air, taking advantage of unlimited selectivity in relation to oxygen transfer. Electrically driven solid electrolyte membranes are also used for removal of residual oxygen from the flow of inert gases, where the application of a sufficient voltage to the membrane can reduce the activity of oxygen retentate gas stream to very low values. However, many of these materials do not have sufficient conductivity of oxygen ions. Only recently were synthesized materials have sufficiently high conductivity kisani based on these materials commercial methods of separation, purification and enrichment of gases. In the prior art also has not been discussed ways to combine the separation of oxygen to the process of oxygen-enriched combustion.

The inventors are not aware of the disclosure in the prior art configuration of a method for combining ion transport, based on the system of obtaining oxygen, with ACS.

In light of the foregoing object of the invention is the elimination of the need for separately located oxygen generator or system supplies oxygen and ensuring effective United way of enhanced oxygen combustion by thermal and operational consolidation of various operations of the method.

Another object of the invention is to minimize or eliminate the formation of NOxin the process of combustion, and heat losses that occur as a result of heating the nitrogen gas.

Another object of the invention is the recovery of a rich nitrogen gas flow from the module ion transfer for use as a companion product.

Another object of the invention is to regulate the concentration of oxygen in pony supplied gas flow, containing elemental oxygen in oxygen-enriched gas stream and oxygen-depleted gas stream, in which oxygen-enriched gas stream is used in the combustion chamber, thus this method includes the following stages:

a) compress the intake gas flow;

b) separating the oxygen from the compressed gas stream using an ion transport module including an ion transport membrane that has a delay side in proteau side to separate the purified oxygen gas flow at pronicheva side and respectively to the depletion of oxygen at the holding side for receiving the oxygen-depleted gas stream, the cleaned gaseous stream of oxygen mixed with other gas components on pronicheva side with the formation of oxygen-enriched gas stream; and

C) blowing pronicheva side of the ion transport membrane, at least part of the gas flow of the combustion product obtained from the combustion in the combustion chamber of a gas stream leaving pronicheva side of the ion transport module.

In a preferred embodiment of the invention the supplied gas stream is used to purge pronicheva side of the ion transport membrane, includes a reactive gas which reacts with the purified gas stream of oxygen penetrating through the ion transport membrane. In yet another preferred embodiment of the invention the gas flow of the combustion product is cooled before using it to purge pronicheva side of the ion transport membrane. In one preferred embodiment of the invention the gas stream coming from pronicheva side of the ion transport module has an oxygen concentration from about 10% to about 90%. In another preferred embodiment of the invention the supplied gas stream is compressed before feeding it into the ion transport module. In one preferred embodiment of the invention the combustion chamber combined with ion-transport module with pronicheva side of the ion transport membrane.

In another preferred embodiment of the invention, at least part of the gas flow of the combustion product use in processing downstream, and at least part of the gaseous product stream formed in the processing downstream, can be used to purge pronicheva side of the ion transport membrane. In another embodiment of the invention, the oxygen-containing gas obtained by the gas flow is passed through a secondary device for combustion from the combustion of any fuel, remaining in the gas stream of product formed in a downward gas flow. In one preferred embodiment of the invention and the combustion chamber and the process flow together with the ion transport module pronicheva side of the ion transport membrane. In another preferred embodiment of the invention process in a downward flow involves the oxidation of metals, cleaning of metals by oxidation of the impurities present in the metal, or an oven with a blow.

Other objectives, features and advantages of the invention will become obvious to a person skilled in the art from the following description of the preferred variants of the invention and the accompanying drawings, on which:

Fig. 1 is a schematic diagram showing the Association of receipt of the oxygen ion transport method with oxygen-enriched combustion and process downstream;

Fig. 2 is a schematic diagram showing the Association of ion-transport method of obtaining oxygen from the oxygen-enriched combustion and process downstream, just as is shown in Fig. 1;

Fig. 3 is a schematic diagram similar to Fig. 2, where the Cam is thus the process of ion transport, the combustion chamber and the processing downstream merge into a single module.

Hereinafter the invention will be described in detail with reference to the drawings in which the same numerals indicate the same elements.

The invention discloses the configuration of the method, providing attractive from an economic point of view, the Association of ion-transport method of obtaining oxygen from the oxygen-enriched combustion (ACS). Although the methods, driven by pressure, are preferred due to the simplicity of their design, the concept presented in this application is applicable to systems using either an ion-conductive membrane having electrodes and an external circuit to return the electrons, or a mixed conducting membrane.

Existing commercial processes for the production of oxygen typically operate at temperatures below 100oC. due to such a low temperature, they will not give significant effectiveness when combined with the ACS process. High temperature process (usually higher than 600oC) make the method of ion transfer well suited for integration with high-temperature method, such as burning, which is with to improve the ion-transport membranes. Traditional methods of obtaining oxygen (e.g., PSA, TSA or membrane methods) can not profitable to use flue gases because of their high temperature at the exit of the combustion chamber.

The essence of the configuration of the proposed method is ion-transport membrane, which uses solid conducting oxygen ions or a mixed conducting membrane for separation of oxygen from oxygen-containing gas, usually, but not necessarily, air, and for the utilization of oxygen released in the process of passing the gas stream, including, but not limited to, oxygen-enriched combustion. To reduce the partial pressure of oxygen penetrating the side of the ion transport membrane oxygen-depleted gas (for example, waste gases of the combustion process or any process of passing the gas stream) is used as the purge gas flow. This purge significantly increases the driving force through the ion transport membrane and gives a great oxygen flow and requires lower surfaces of the membranes. These benefits increase, even when the feed gas stream is under relatively low pressure, thereby reducing the system's needs in electricity is estom way since it provides a flow of dilution gas, which is important for regulating the temperature in the combustion chamber and to minimize the formation of NOx(for example, from leaching of nitrogen). The efficiency of this process could also be enhanced by adding fuel to the flue gas flowing in the oxygen separator. This further reduces the partial pressure of oxygen on the penetrating side, resulting in a large flow of oxygen ion transport separator. In some embodiments of the invention the ion transport module can also function as a combustion chamber, thereby eliminating the need for a separate combustion chamber, unless you want the temperature leaving the combustion chamber of the gas stream above 1100oC, which is the maximum operating temperature of many existing ion-transport membranes. It should be noted that the heat necessary to maintain the temperature of the ion transport module needed to work within, may come from various sources, known to experts in the art, including, for example, the heat generated by the secondary device for burning, and recycled hot gotoblas is here much greater than the conductivity of oxygen ions in these operating temperatures, and the whole transfer of oxygen from one side to the other is controlled by the conductivity of oxygen ions. A significant number of potential mixed conductors detected in fluorite, and in perovskite crystal structures. The behavior of ion transport membranes were carefully studied (for example, for fuel cells) and can be accurately modeled. Table 1 presents a partial list of mixed conductors of interest for oxygen.

Fig. 1 is a schematic diagram showing the Association of ion transport process of obtaining oxygen from the oxygen-enriched combustion. During the work process the feed gas stream 1 containing elemental oxygen, usually air, is compressed to a relatively low pressure in the ventilator or compressor 2 to receive the compressed feed stream (3) gas, which is heated in the heat exchanger 33 against the flow 31 of the exhaust gas and flow 37 formed of nitrogen to obtain heated supplied gas stream 4. Thread 28 of the gas can be separated from the heated feed gas stream 4 and use the optional secondary device 26 for combustion, leaving the thread 5 podvergatsya thread 6 of the injected gas then flows from the discharge side of the ion transport module 35, consisting of ion - transport membrane 7 having a retaining side 7a and proteau side 7b. Part of the oxygen in the hot flow of 6 gas return in ion transport module 35, and the output gas stream 8 becomes enriched in nitrogen compared with stream 1 of the injected gas. Proteau side 7b of the ion transport membrane 7 is blown through the thread 9 purge gas containing the combustion products. Thread 10 penetrating gas contains oxygen, and this thread is 10 gas later mixed with stream 11 flue gas. The gas flux 10 optional add thread 12 of the air.

Thread 13 hot gas after passing through the optional present a ventilator (not shown), enters the combustion chamber 14. Optionally or in addition to, the thread 11 of the combustion gas stream 15 flue gas can be fed directly into the combustion chamber 14. If the combustion chamber 14 operates in the regime close to the stoichiometric or some saturation of the fuel, the oxygen concentration in the exhaust gas stream 16 can be maintained at a low level. In this embodiment of the invention, the thread 16 of the exhaust gases from the combustion chamber 14 is divided into two parts, the gas flow 17 and the gas flow 18. Pathology the flow of exhaust gas 20 from the processing downstream 19 can also be divided into two parts, the flow of exhaust gas 21 and the flow of exhaust gas 22. To the flow of exhaust gas 21 you can add the thread 25 of the combustion gases for the formation of the gas stream 38.

The gas stream 38 can be added to the gas stream 17 to form gas stream 9, which enters the ion transport module 35 and is used to purge pronicheva side 17b of the ion transport membrane 7. Although not shown here, the gas stream 17 can be used for heating the heated stream 5 is supplied with gas through a heat exchanger to produce hot thread 6 of the injected gas, instead use the optional heater 34. Thread 22 of the exhaust gas is not necessarily served in the optional secondary device for the combustion chamber 26, where the air stream 27 or gas flow 28 do not necessarily add to produce hot stream 29 exhaust gas. Hot thread 29 of the exhaust gas can be a gas stream 30 or gas stream 31. As indicated above, the gas flow 31 is used in the heat exchanger 33 for heating flow 3 compressed gas supplied to receive the stream 32 exhaust gas. The gas stream 30 may be removed by gas flow-retentate 8, rich in nitrogen if nitrogen is not used as septate 8, apparently, must be at a higher pressure than the flow 30 of the exhaust gas and, it may be necessary to release excess pressure of the gas flow-retentate 8 using expansion valve 23 to receive the stream of gas-retentate 24 before it is mixed with the gas stream 30. If it is desirable that the gas flow - retentate 24 was a product flow with a high nitrogen content gas streams 36 and 30 do not mix.

The use of depleted oxygen flow purge gas 9 in the ion transport module 35 significantly reduces the partial pressure of oxygen at proteau side 7b of the ion transport membrane 7 and provides quick transfer of oxygen through the membrane 7. The flue gas flows 11, 15 and 25 can be introduced into the process in any or all of the points marked in Fig. 1; a necessary condition for the invention is the use of at least one of flow of the combustion gas. For example, it may be desirable to add a stream of flue gas 25 in the opposite direction to the flow through the ion transport module 35 to dramatically reduce the partial pressure of oxygen at proteau part 7b of the ion-transport, thus partially offset the needs for heating necessary for oxygen transport. In this case, emerging from the ion transport module 35, the gas stream 8 with high nitrogen content can be more hot. This makes more efficient heat transfer in the heat exchanger 33, thereby reducing the surface area required for heat transfer, and potentially eliminating the need for a heater 34, located above the ion transport module 35. Assuming burning enough fuel in the ion transport module 36 for blown or pronicheva side 7b of the ion transport membrane 7 can completely eliminate the need for a separate combustion chamber 14, i.e., ion transport module 35 will serve as a combustion chamber (as shown in Fig. 3). In such situation, you can get significant system simplification and cost reduction.

Reactive purging systems are disclosed in "Reactive Purge for Solid Electrolyte Membrane Gas Separation", U. S. Serial. 08/567,699 filed December 5.1995 and incorporated into this description by reference. The preferred scheme for ion transport modules that use reactive purge is disclosed in "Solid Electrolyte Jonic Conductor Reactor Deseng", U. S who with the combustion chamber 14, working with a mixture of slightly enriched fuel, because it leads to partial oxidation of the fuel added to the gas flow permeate 10, resulting in the flow 16 of the exhaust gas, containing hydrogen and carbon monoxide. As noted above, the gas stream 17 is not necessarily used for purging pronicheva side 7b of the ion transport membrane 7. It should be noted that hydrogen gas is vysokoreaktsionnye gas with a higher reactivity than many other gaseous fuels, and its presence in the ion transport module 35 leads to a very low partial pressure of oxygen at proteau side 7b of the ion transport membrane 7, and this provides a more rapid transfer of oxygen through the ion transport membrane 7. Of course, such results are achieved by the introduction of gaseous hydrogen in the flow of flue gas 25, however, it is not economically advantageous, as for example, the supply of enriched fuel mixture in the combustion chamber 14, since hydrogen gas is a relatively expensive fuel. Supply of enriched fuel mixture in the combustion chamber 14, as described, eliminates the need ISpac part of the cycle of this process. The combustion chamber 14 in the presence of a significant amount of fuel may, however, cause the threads 18 and 22 of the exhaust gas will contain carbon monoxide and hydrogen gas, both gas can simply be released into the atmosphere under the condition of low concentration. As mentioned above, you can however install a secondary combustion device 26 (possibly catalytic), to which is added an excess amount of air 27 for burning carbon monoxide and hydrogen gas, if their concentration is high enough. The gas stream 28 is heated stream 4 of the injected gas can also be added to the secondary device for burning 26 to provide the necessary conditions for the secondary combustion device.

It is interesting to note that due to the advantage of recirculatory products of combustion, such as stream 9 purge gas, as well as through an unrestricted selectivity of ion transport membrane 7 in the case of oxygen, it becomes possible to limit the temperature increase of the gas flow 13 in the combustion chamber 14, precluding the need for an excessive amount of air, and thereby to eliminate the nitrogen from the combustion process that prevent the characteristic of the many variations of the invention.

Typical limits of operating parameters of the ion transport module used according to the invention, the following.

Temperature: usually within 400-1000oC, preferably 400-800oC.

Pressure: the pressure on the winding side is typically 1-3 ATM. The pressure on the inlet side of the gas flow is 1-3 ATM, when nitrogen is not a byproduct, and 1-20 ATM, if nitrogen is a byproduct.

The conductivity of oxygen ions ( i) ion-transport membranes: Typically in the range from 0.01 to 100 S/cm (IS =1/Ohm).

The thickness of the ion-transport membranes: Ion-transport membrane can be used in the form of a thick film or thin film on a substrate of a porous substrate. The thickness (t) of the ion - transport membrane/layer typically less than 5000 microns; preferably less than 1000 microns and most preferably less than 100 microns.

Configuration: the Elements of the ion-transport membrane may be cylindrical or flat.

As mentioned above, asymmetric or composite ion-transport membrane (i.e., driven by pressure) used in the examples discussed in this description. The following characteristics are based on ti is finding. The effective thickness of the membrane: 20 mm

Ionic conductivity, i: 0.5 S/see

Working temperature: 800oC.

The porosity of the substrate: 40%.

To determine the operating parameters of the process shown in Fig. 1, such as the membrane surface area, the supply of electricity and heat at various points, were used standard mathematical models. This example, modeling the process using the circuit of Fig. 1 is presented for illustrative purposes only, there have been no attempts to optimize the process. The main reason why no attempt was made optimization, is that the basis of the optimization are economic considerations, and commercial production of ion-transport membrane systems have not yet entered into force and there is currently no reliable estimates of the cost of such systems.

For this example of Fig. 1 shows that the fuel is added to the process stream 11 flue gas. In addition, do not take into account an optional gas flow 17, i.e., the gas streams 16 and 18 are identical. In addition, nitrogen is undesirable as a companion product, and the gas flow-retentate 36 obtained from the gas flow-retentate 8 last is from a thread 29 of the exhaust gas. However, as a rule, the pressure drop of the gas flow-retentate 8 or adding gas stream 30 to the gas flow-retentate 8 upstream from the heat exchanger is not effective. Because the thread 22 of the exhaust gas does not contain carbon monoxide and hydrogen gas, the secondary combustion device 26 is not set. Basic data for example: processing downstream, requiring heat flow to 5 million BTU /HR (1260 thousand kcal/h).

Fig. 2 is a schematic diagram similar to that shown in Fig. 1, which shows a more efficient version using catalytic secondary installation for combustion. In the process, the thread 41 of the injected gas containing elemental oxygen, usually air, is compressed to a relatively low pressure in the ventilator or compressor 42 for receiving the compressed stream 43 of the injected gas, which is heated in the heat exchanger 73 with countercurrent hot exhaust gas 40 and the flow of 64 products of nitrogen gas to obtain heated thread 44 of the injected gas. The gas stream 70 can be separated from the heated stream 44 of the injected gas and to use the optional secondary combustion device 69, leaving the thread 74 of the injected gas, to the gas to 45 then fed to the feed side of the ion transport module 46, containing ion transport membrane 47, having a retaining side 47a and proteau side 47b of the oxygen in the hot gas stream 45 is removed in the ion transport module 46, and the output stream 48 gas becomes enriched in nitrogen compared with stream 41 of the injected gas.

Proteau side 47b of the ion-transport membrane 47 purge using gas flow to purge 79 containing combustion products. The gas flow of the permeate 50 contains oxygen, and this gas stream 50 is then mixed with stream 51 flue gas. The air flow 52 is not necessarily added to the gas stream 50. Thread 53 of combustion gas after passing through the optional ventilator (not shown) is supplied into the combustion chamber 54. Optionally or in addition to the gas stream 51, the flow of the combustion gas 55 may be directly added to the combustion chamber 54. When the combustion chamber operates at stoichiometric or slightly increased amounts of fuel stream 56 of the exhaust gas can be maintained at a low level.

The thread 56 of the exhaust gas from the combustion chamber 54 can be divided into two parts - gas stream 57 and the gas flow 58. The gas flow 58 is used for processing downstream 59, which require the you can also be divided into two parts - the flow of exhaust gas 61 and the flow of exhaust gas 62. The flow of the combustion gas 65 can be added to the flow of exhaust gas 61 for receiving the gas stream 78. The gas stream 78 can be added to the gas stream 57 for receiving the gas stream 79, which enters the ion transport module 46, and it is used for blowing pronicheva side 47b of the ion-transport membrane 47.

The flow of exhaust gas 62 is not necessarily divided into two parts, the flow of exhaust gas 40 and the gas stream 77. As mentioned above, the flow of exhaust gas 40 is used in the heat exchanger 73 for heating the compressed flow of the injected gas 43 to receive the flow of exhaust gas 74. The gas stream 77 can be mixed with enriched nitrogen gas retentate 48 if the nitrogen is not used as a companion product, and if the temperature of the flow of exhaust gas 77 correspondingly high. The purpose of this stage is the removal of any unreacted fuel in the flow of exhaust gas 62 by combustion in the secondary device for burning 69, as well as generating heat energy to increase the efficiency of the heat exchanger 73. The gas flow-retentate 48, apparently, will be under higher pressure than the flow otruba 48 using the expansion valve 63 for receiving the gas flow-retentate 76 before as it is mixed with the gas stream 77 for receiving the gas stream 80.

The gas flow 80 serves in an optional secondary device for burning 69, where the gas stream 70 does not necessarily add to produce hot exhaust gas flow 39. In this case, you must make sure that the flow of 80 contains sufficient for combustion of the amount of oxygen in order to bring this process to completion. As indicated above, the gas stream 70, taken to a heated flow of the injected gas 44, optional add on a secondary device for the combustion of 69. It should be noted that the volumetric rate of the combined gas stream is increased by mixing the exhaust gas from the ion transport module 46 and processing downstream 59. This increases the coefficient of capacity in the heat exchanger 73 and increases the transfer of heat from the compressed gas stream 43. The gas product stream 64 contains oxygen (used in excess to ensure complete combustion and combustion products if use a secondary device for burning 69, and the gas flow of the product is usually produced as exhaust stream.

As for the variant of the invention shown in Fig. 1, using Obedinenie oxygen pronicheva side 47b of the ion-transport membrane 47 and provides quick transport of oxygen through the membrane 47. The flue gas flows 51, 55 and 65 can be entered in the scheme of process in any or all of the points marked in Fig. 2, which is an advantage of the invention, and it is important for the invention is the use of at least one of flow of the combustion gas. As before, it may be desirable to add a flow of the combustion gas 65 is opposite to the flow of ion transport module 46 so that substantially reduce the partial pressure of oxygen at pronicheva side 47b of the ion-transport membrane 47. As a result, some of the heat generation in ion - transport module 46 due to fuel combustion, partially satisfying, therefore, needs heat energy required for the transport of oxygen. In this case, facing enriched nitrogen gas stream 48 from the ion transport module 46 can be made more hot that will make the heat transfer in the heat exchanger 73 is more efficient due to this, it is possible to reduce the surface area required for heat transfer, it is also potentially eliminates the need for the heater 75 is higher ion transport module 46. If burned enough fuel in the ion transport module 46 on pronicheva side 47b of the ion-transport mže can serve as a combustion chamber (as shown in Fig. 3). In such situation, you can get a significant simplification of the system and economic benefits.

In a variant of the invention shown in Fig. 1, can be advantageous when the combustion chamber 54 operates with a mixture of slightly enriched fuel, as this may cause partial oxidation of the fuel added to the gas flow permeate 50 that gives the flow of exhaust gas 56, containing hydrogen and carbon monoxide. As noted above, the gas stream 57 is not necessarily used for purging pronicheva side 47b of the ion-transport membrane 47 and the presence of gaseous hydrogen in the ion transport module 46 leads to a very low partial pressure of oxygen at pronicheva side 47b of the ion-transport membrane 47, it also provides a more rapid transfer of oxygen through the ion transport membrane 47. The use of rich fuel stream supplied to the combustor 54, leads to the formation of gaseous hydrogen, which is part of the technological cycle. As stated above, you can install a secondary device for burning 69 (possibly catalytic) for complete combustion of carbon monoxide and hydrogen gas, if their concentration to etenia, in which the combustion chamber combined with ion transport module, i.e. when the ion transport module itself performs the function of the combustion chamber. In the way the flow of the injected gas 81 containing elemental oxygen, usually air, is compressed to a relatively low pressure in the ventilator or compressor 82 for receiving the supplied compressed gas stream 83, which is heated in the heat exchanger 113 with countercurrent flow of hot exhaust gas 116 and the finished product nitrogen 93, while receiving heated gas stream 95. The gas stream 110 can be separated from the stream of heated gas 95 and use the optional secondary device for combustion 109, leaving the flow of the injected gas 84, which is optionally heated in the heater 114 to produce hot feed flow gas 85. The hot gas stream 85 is then fed to the inlet side of the ion transport module - combustion chamber 86 containing ion transport membrane 87 having a retaining side 87a and proteau side 87b. Some of the oxygen in the hot gas stream 85 is removed in the module 86 ion transport - the combustion chamber, and the exit gas stream 88 becomes enriched in nitrogen compared with stream supplied gas 81.

the 89, containing combustion products and fuel. The gas flow of the permeate 90 contains oxygen, and the air flow 92 does not necessarily add to the gas flow 90 to obtain a gas stream 98. During operation of the ion transport module - combustion chamber 86 in conditions close to stoichiometric or slight saturation of the fuel, the oxygen concentration in the flow of exhaust gas 90 can be maintained at a low level. The gas stream 98 is used in the processing of downstream 99, which requires heat, and relatively cooler flow of exhaust gas from 100 processing downstream 99 also divided into two parts - the flow of exhaust gas 101 and the flow of exhaust gas 102. The flow of the combustion gas 105 is preferably added to the flow of exhaust gas 101 for receiving the gas stream 89, which enters the module 86 ion transport - the combustion chamber and is used to purge pronicheva side 87b ion - transport membrane 87.

The flow of exhaust gas 102 is not necessarily divided into two parts - the hot stream of exhaust gas 116 and the gas stream 115. As noted above, the hot stream of exhaust gas 116 is used in the heat exchanger 113 to heat the compressed flow of the injected gas with 83 receiving stream is not from use as a companion product, and if the temperature of the flow of exhaust gas 115 correspondingly high. The purpose of this stage is to remove any unreacted fuel in the flow of exhaust gas 102 by combustion in the secondary combustion device 109, as well as generating heat to increase the efficiency of the heat exchanger 113. The gas flow-retentate 88 apparently is at a higher pressure than the flow of exhaust gas 115, and may be

you must release the excess pressure of the gas flow-retentate 88 using the expansion valve 103, receiving the gas flow-retentate 118 prior to its mixing with the gas stream 115 for receiving the gas stream 119.

The gas stream 119 is served in the optional secondary combustion device 109, where the gas flow 110 does not necessarily add to produce hot exhaust gas flow 93. In this case, you must ensure that the stream 119 contains enough oxygen to bring the combustion to completion. As indicated above, the gas stream 110, taken from the warm flow of the injected gas 95, optional add in the secondary combustion device 109 to ensure complete combustion. It should be noted that the volumetric rate of the combined flow is increased due to the mixing of exhaust gas from an ion-crabmania 113 and increases the heat transfer to the compressed gas stream 83. The gas flow 94 contains oxygen (used in excess to ensure complete combustion and combustion products, if you use the secondary combustion device 109, and the gas flow 94 is normally destroy as exhaust gas.

In a variant of the invention according to Fig. 3 heat of reaction formed in the ion-transport and combustion module 86, delete from or use in the combustion chamber to the convection and/or radiation the transfer of heat.

For example, ion-transport membrane 87 may be formed in the shape of a cylinder, inside of which flows the stream of reactive purge gas 89. Because of the heat generated in the winding side 87b ion-transport membrane 87 formed in the shape of a cylinder, the cylinder temperature is high and they will act as heating elements. Cylinders ion-transport membrane 87 will radiate heat to keep the side 87a or proteau side 87b during the flow of processes such as glass melting or annealing of metals. Also part of the heat formed in the ion transport module 86 can be used for preheating the compressed feed gas stream 85 and flow producing the lubricant of the furnace will be in this case pronicheva side 87b ion-transport membrane 87 (i.e., on the side with oxidizing groove).

You can also combine ion-transport combustion module with internal circulation furnace gas furnace gas). If the furnace and ion-transport combustion module operate at approximately the same temperatures (e.g., 800-1200oC), then the ion - transport combustion module can be placed directly into the oven under the condition that the atmosphere of the furnace "clean", i.e. does not contain any substances that are harmful to the ion transport membrane. One way of implementing this idea is shown in Fig. 4, in which the process of ion transfer, combustion chamber and processing downstream combined into a single unit. The feed stream 132, such as heated air, is directed through the cathode side of the membrane 120a 120 for receiving hot hypoxic retentate 134, such as nitrogen. Processing downstream 130 (e.g., a furnace) is shown in pronicheva or anode side 120b of the ion-transport membrane 120. In this scheme, the flow of the combustion gas 121 serves close to the surface pronicheva side 120b, thereby driving and/or effectively consuming the oxygen transported through the ion-transport membrane 120. The combustion products in the hot zone 138 of mogli, it is shown in Fig. 4, the flow of products of combustion 146, preferably obtained from the furnace 130, as shown by the dotted line flow 146a, and the flow of the combustion gas 121 is not necessarily served through the layer of porous fuel distributor 122, adjacent to pronicheva side 120b of the ion-transport membrane 120. Preferably, the layer of the distributor 122 define at least one passage or fully for a more uniform distribution of fuel through the membrane 120.

Reacted permeate 136 containing oxygen and combustion products are directed into the furnace 130 through the hot zone 138. Preferably, part of the hot nitrogen 140 is directed through the valve 142 to provide an inert atmosphere in the whole furnace 130. If you want, you can add additional 133 fuel into the furnace 130.

In another design, ion-transport membrane 120 is part of a separate module that is external to the furnace 130. Both external and joint designs, you can install a two-stage system of ion migration, in which an anode side of the first stage purge flow retentate from the first stage to obtain a diluted oxygen permeate, while the anode side of the second stage reaction product to propylsilane hot streams of nitrogen retentate in the atmosphere of the furnace.

When the peak value of the temperature of the furnace is much higher than the temperature of the ion transfer, you can choose the area of the furnace with the "correct" temperature for the ion transfer (for example, the preheating section or furnace continuous reheating), or you can make a special camera with the right bends heat for temperature control. For example, in steam boilers or heaters for oil, can be used in a furnace charging device for heating (pipes for water or oil) to create a zone of optimum temperature for ion transport module. Through this zone provide circulation of a large amount of flue gas to the constant blowing of oxygen to maintain an oxygen concentration at a low level. Low oxygen concentration and a strong circulation furnace gas provide synergies with the way dilute oxygen combustion.

The combined method according to the invention has many advantages. For example, the oxygen for the ACS can be extracted from the feed flow low pressure gas using the flow of exhaust gas for purging, it gives low energy consumption for separation of oxygen.

Pascalc the CMOS purge gas is not added no nitrogen. Even if in the mixture for combustion of the injected air, either intentionally (for example, an optional gas stream 12), or as a result of leakage, the fraction of nitrogen in the mixture of combustion will be very small. This minimizes or eliminates the formation of NOxin the combustion chamber.

In addition, by suitable mixing of the exhaust gas taken before and after processing downstream, it is possible to control the inlet temperature of the exhaust to get for the ion transfer. This can eliminate the need for separate pre-heating the purge gas.

Moreover, if the combustion of the total amount of fuel can be performed in the ion transport module, a separate block of the combustion chamber can be eliminated. This will give a significant simplification of the overall system cost savings. Further, if the ion transport module remove enough oxygen from the flow of the injected gas, then enriched nitrogen stream retentate from the ion transport module can be used as a product. This will be the most attractive, if you add some fuel, for example, the flow of the combustion gas 11. If you want to get nitrogen as a companion productsthe product. However, in this case, the gas flow - retentate from the ion transport module can not be mixed with the flow of exhaust gas from the processing downstream. In this case, you can either install a separate heat exchanger for recovering heat from a flow of exhaust gas, or do any attempts by heat recovery, because usually the flow of exhaust gas is much smaller and colder than the gas flow-retentate.

In addition, the flow of purge gas reduces the oxygen concentration in pronicheva side of the ion transport membrane. Reduced oxygen concentration makes the structure of the ion transport module and processing components downstream (e.g., combustion chamber) on the winding side is much easier from the point of view of materials. In the absence of a bleed stream of essentially pure oxygen can be obtained on pronicheva side of the ion transport membrane. There are security issues associated with the handling of the flow of such pure oxygen, especially at high temperatures.

In addition, the oxygen concentration in the blowdown exhaust gas can be easily controlled with the help of R is knogo gas (increased recycling of combustion products), by changing the temperature of the ion transport module, or using different surface area of the membrane stage ion transfer. These techniques are also effective in the control of the total quantity of oxygen that is separated, and can be used to control loading.

Finally, the use of ion transport separator eliminates the need for separately operating the oxygen generator (e.g., PSA) or in the oxygen system (for example, a reservoir for liquid or evaporators). This should bring significant savings in capital costs and reducing the cost of obtaining oxygen.

It should be noted that there are various modifications of the method, not beyond the ideas and the configuration of the method discussed above. For example, it may be advantageous to use the exhaust gas from the processing downstream for heating the feed gas stream. You can also add a certain amount of air to flow purge gas emerging from the ion transport module. This may be particularly desirable for initial operations or to control the load. In addition, although the described method is suitable for working under Yes the and to the primary ion conductors, driven electrically or under pressure. And finally, while in Fig. 1 shows a method of providing oxygen in counter-current mode, the same process can be performed in mode unidirectional flow or overlapping stream.

As mentioned above, the term "solid electrolyte ionic conductor", "solid electrolyte", "solid Explorer" and "ion transport membrane" is used here mainly to denote any system of ionic type (elektroprivodiv) or a mixed system conductive type (pressurised), unless otherwise indicated.

The term "nitrogen" as it is used herein, generally means oxygen-depleted gas, namely oxygen-depleted in comparison with the supplied gas. As discussed above, ion-transport membrane is only permeable to oxygen. Therefore, the composition of retentate depends on the composition of the injected gas. Of the supplied gas to remove oxygen, but he keeps the nitrogen and other gases (such as argon), which are present in the feed gas. The meaning of the term will be clear to a person skilled in the field of technology in the context in which this term is used in this invention.

As he is another element in the Periodic table. Although usually it is present in the diatomic form of elemental oxygen includes separate oxygen atoms, triatomic ozone and other handicaps, not connected to other elements.

The term "high purity" refers to the flow of the product, which contains less than 5% by volume of unwanted gases. Preferably, the product is clean at least 98,0%, more preferably 99.9%, and most preferably 99.99% pure, where "pure" indicates the absence of undesirable gases.

"Adsorption-induced pressure change" or "PSA" system refers to systems using adsorption materials, selective with respect to gas, usually nitrogen, to separate the gas from the other gases. Such materials include speed-selective PSA materials, which is usually carbon, and nitrogen high pressure and low pressure oxygen, and renovasculature PSA materials that typically contain lithium and provide a low pressure nitrogen and oxygen at high pressure.

Specific features of the invention are represented by one or more of the drawings for convenience only, as each distinctive feature can be combined with another Oh, shown without departure from the substance of the invention. Such modifications may include using layers of adsorption caused by changes in pressure or temperature, or other methods to separate the main quantity of oxygen to ensure the functioning of polymeric membranes discussed above. Alternatives will be clear to experts in the field of technology, and they must be included in the scope of the invention according to the claims.

1. The method of separation of flow of the injected gas containing elemental oxygen, oxygen-enriched gas stream and the oxygen-depleted gas stream, in which oxygen-enriched gas stream is used in the combustion chamber, characterized in that it includes (a) compress the intake gas stream; (b) separating the oxygen from the compressed gas stream using an ion transport module including an ion transport membrane having a holding side and proteau side to separate the purified oxygen gas flow at pronicheva side and respectively holding the oxygen on the retention side for receiving the oxygen-depleted gas stream, when this purified oxygen gas flow spot thread and (C) a blowing penetrating side of the ion transport membrane at least part of the gas flow of the combustion products derived from the combustion in the combustion chamber of a gas stream leaving pronicheva side of the ion transport module.

2. The method according to p. 1, characterized in that the flow of the injected gas is air.

3. The method according to p. 1, characterized in that the gas flow of the combustion products used for blowing pronicheva side of the ion transport membrane, includes a reactive gas which reacts with purified oxygen stream, penetrating through the ion transport membrane.

4. The method according to p. 1, characterized in that it includes a cooling gas flow of the combustion products before using it to purge pronicheva side of the ion transport membrane.

5. The method according to p. 1, characterized in that the gas stream leaving pronicheva side of the ion transport module has an oxygen concentration from about 10% to about 90%.

6. The method according to p. 1, characterized in that it involves the heating of the supplied compressed gas stream before it is served in the ion transport module.

7. The method according to p. 1, otlichuy the second membrane.

8. The method according to p. 1, characterized in that at least part of the gas flow of the combustion products used in processing downstream.

9. The method according to p. 8, characterized in that the combustion chamber and the processing downstream combine with ion transport module with pronicheva side of the ion transport membrane.

10. The method according to p. 8, characterized in that at least part of the gaseous product stream processing downstream use for blowing pronicheva side of the ion transport membrane.

 

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