Indirect fired gas turbine integrated with an air separation unit

Gas turbine systems provide a force or shaft or piston-work or performance by the expansion of hot, pressurized gas flows, directly or indirectly by the combustion of solid, liquid or gaseous Fuels were produced, available. A gas turbine system uses one or more air compressors, mechanically connected to a or more expansion turbines are connected to shaft or Kraft work Means of transport, power generation, industrial processes, and many other well-known Applications available deliver.

Gas turbine systems can according to the prior art as fired directly, indirectly fired or combination systems are classified. In a direct-fired gas turbine system is compressed air with a fuel, typically a Gas or light hydrocarbon liquid, burned with the hot, pressurized combustion gases directly into the expansion turbine expand. Hot off the Gas expansion turbine can be regenerated extra work are, for example, by generating steam for expansion in a steam turbine. Direct-fired gas turbine systems are open systems, where the working fluid of the expansion turbine (ie combustion products) after appropriate recovery into the atmosphere is omitted.

in an indirect fired gas turbine system is a working fluid (Typically air) in the gas turbine compressor compresses, by indirect heat exchange with a hot, external gas stream (the one typically by burning of solid, liquid or gaseous received fuel) is heated, so hot yourself, pressurized air yields, and expanded in the expansion turbine, to generate power work. The exhaust steam of the expansion turbine may be used to preheat the combustion air, or can be directly in the introduced combustion step will. Indirectly fired gas turbines offer closed Cycle are operated with a recycled, gaseous working fluid means a fully integrated compressor and an expansion turbine compresses, heated expanded and cooled becomes.

in the Prior art are combined gas turbine systems are known in which fired a direct-fired gas turbine with an indirect Gas turbine is integrated. In such systems, the indirect fired gas turbine be a partially closed system in which a major part of the exhaust steam of the indirect fired turbine cooled and is returned to the compressor.

The summarized above types of gas turbine systems are described in detail in Standard textbooks as The Mechanical Engineer's Handbook, edited by M. Kurtz, John Wiley & Sons, Inc, 1986, Chapter 72, pages 1984-2009 and Marks' Standard Handbook for Mechanical Engineers, published by EA Avallone and T. Baumeister III, McGraw-Hill Book Co., New York, ninth edition (1987), pages 9-118 to 9-123 described.

The Separation of air into its components is by compressing the air, the pretreatment of the compressed air when it is necessary is to eliminate certain impurities and disassembly of the purified, compressed air by known methods of cryogenic distillation, pressure swing adsorption, penetrable polymeric membranes or mixed with ceramic conductor membranes for high Temperatures performed. The energy for compressing the air can by electric motors, Gas or steam turbines, or combinations of electric motors asked and gas or steam turbines driving means available will. The selection of the compressor drive means is supported by numerous Design factors such as the nature of the air separation process, the size of the process plant, the place, the cost of electricity, the availability of fuel and the possibility for the Integration of the air separation process with the compressor drive means dictated. additionally , the air separation system and the compressor drive means be integrated with a process which comprises (s) products) of the air separation process uses.

in a number of air separation process is a gas turbine, the preferred compressor drive means. One of these is the integrated, combined Vergasungszyklus- (integrated gasification combined cycle - IGCC) Process in which coal or other carbonaceous material is gasified with oxygen, wherein the generated gas is cleaned, so that it results in a low-sulfur fuel gas. This fuel gas is used in a direct-fired gas turbine, the generator a drives to electrical power with reduced environmental emissions to create. The oxygen is by air separation by cryogenic generated, wherein some or all of the compressed Lufteinzuführung by the gas turbine compressor to disposal can be provided and the nitrogen-rich byproduct gas kom from the air separation systemprimiert and into the incinerator introduced the gas turbine becomes.

A general overview the current Technology the IGCC power generation systems is of TM in Todd an article entitled "Clean Coal Technologies for Gas Turbines "given that at the GE Turbine State-of-the-art presented 18 - Technology Seminar in July 1993 on pages 1 has been. An overview of various Integration processes and their impact on the GCC economy is in a lecture by AD Rao et al entitled "Integration of Texaco TQ Gasification with Elevated Pressure ASU "given that on the 13th EPRI Conference on Gasification Power Plants, San Francisco, CA, from 19th - 21st October was presented 1994th In a lecture entitled "Improved IGCC Power Output and Economics Incorporating a Supplementary Gas Turbine ", which on the thirteenth EPRI Conference on Gasification Power Plants, San Francisco, CA, from 19th - 21st October was presented in 1994, consider AR Smith et al various Modes of integration between the gas turbine and air separation unit in an IGCC process.

The Use of the nitrogen-rich byproduct stream through compression and introduction in the combustion device of an IGCC system is described in representative Documents US-A-4,250,704; US-A-4,697,415; US-A-5,081,845; US-A-5 406 786 and US-A-5740673 described. Another method of Use of the nitrogen-rich effluent stream in an integrated Air separation gas turbine system is US Patent 3,731,495, in the publications; US-A-4,019,314 and US-A-5 406 786 describes which stream is heated and optionally is introduced directly into the gas expansion turbine without compression.

Of the Use an indirectly-fired gas turbine with a cryogenic air separation system is described in GB-A-1455960. An air separation unit is integrated with a steam generation system in which a nitrogen-richer Effluent stream by indirect heat exchange with hot, compressed air from the main air compressor of the air separation unit heated wherein the nitrogen-rich stream in a fired heater further heated is and the last, hot, nitrogen-rich stream in an associated nitrogen expansion turbine is work expanded. The by this expansion turbine Work produced drives the main air compressor of the air separation unit at. This exhaust steam from the nitrogen expansion turbine and the combustion gases from fired heater are introduced separately into a fired steam generator to causing steam from the expanding part in a steam turbine can to drive the main air compressor of the air separation unit. is from steam generator cooled nitrogen removed and may be used elsewhere if it required becomes. Optionally, the combustion gases from the fired heater in a Turbine expands, which drives a compressor to a separate, fired heater Combustion air available questions to which heats the nitrogen-rich stream prior to expansion. After another option is the exhaust steam from the nitrogen expansion turbine and combining the combustion gases from the fired heater and in the preheater and Luftvorwärmabschnitte the fired steam generator introduced.

On IGCC system an indirectly fired gas turbine is disclosed in US-A-4,785,621, where a fuel gas from the gasifier in a direct-fired gas turbine imported is that energy generated. A separate, indirect-fired gas turbine system provides extracted air for the air separation system, wherein the exhaust gas from the direct-fired gas expansion turbine by the compressed air indirect heat exchange heated and the heated, compressed air in the indirect fired gas expansion turbine is expanded. The oxygen from the air separation unit entirely used in the gasifier. Before the indirect heating and expansion steps is nitrogen-rich effluent gas from the air separation system mixed with compressed air. The exhaust from the fired indirectly The gas expansion turbine is vented to the atmosphere or to additional Heat recovery used. The preambles of the independent claims of this Application based on US-A-4 785,621.

gas turbines are the preferred drive means in the method for air at high Temperatures in mixed with ceramic conductor membrane systems to disassemble. Direct-fired gas turbines for this application are in the documents US-A-4 545 787; US-A-5,516,359; US-A-5,562,754; US-A-5,565,017 and US-A-5657 624.. A direct-fired gas turbine is in a Air separation system with mixed with ceramic conductor membranes used, the oxygen in a direct recovery method for the reduction iron available provides, as described in US-A-5,643,354. Indirect fired Gas turbines for this application are described in US-A-5,035,727 and in an article entitled "Coproduction of Power, Steam, and Oxygen in Coal or Low Quality Fuel Combustion System "in Research Disclosure March 1995 Pages 181-186 explained.

The Expansion turbine of a direct-fired gas turbine requires Generally less maintenance and has in operation a lower operating availability as the expansion turbine of an indirect fired gas turbine. This is because that since the propellant gas fired directly into the includes gas turbine combustion products, water, carbon dioxide, Sulfur compounds and carbon black include, these by-products pollution, erosion and corrosion in Inside the expansion turbine may cause, whereby the operating availability is reduced. The propellant in an indirectly fired gas turbine on the other hand contains no combustion products, so that the expansion turbine therefore with reduced pollution, erosion and corrosion problems work and a higher operating Availability will have. This advantage of an indirect fired gas turbine is by the recuperative not requiring a gas-gas heat exchanger for high temperature balanced in order to heat the fuel gas prior to expansion, which is not required in a direct-fired gas turbine. The higher operating Availability the indirectly-fired gas turbine, however, the selection of a cheap make driving means possible in certain applications.

The This invention discloses the use of an indirect fired Gas turbine system to the supply compressed air for to provide an air separation system in applications available, where high availability is the driving means necessary. The invention utilizes the integration an indirect fired gas turbine with an air separation system to produce oxygen with more efficient use of the nitrogen-rich Byproduct.

in its broadest embodiment the present invention provides a process for the production of oxygen to disposal, comprising: <ul><li>(I) compressing air to a first and a second pressurized air stream to disposal deliver;</li><li>(Ii) decomposing the first, in the pressurized air stream an oxygen-rich product stream and a nitrogen-rich Byproduct stream;</li><li>(Iii) heating the nitrogen-rich byproduct stream and the second, under Pressurized airflow to heat exchange by indirect with one or a respective, hot process stream a hot, under to provide pressurized gas stream available to a through the combustion of a fuel in a combustion device produced, hot, to provide pressurized gas stream;</li><li>(Iv) work-producing forming expanding the hot, pressurized Gas stream to a shaft or force-work and an expander outlet stream with reduced pressure to produce; and </li><li>(V) utilizing at least a portion of the force-work to work for the Air compression available to provide, characterized in that the fuel with the Air containing expander outlet stream combusted with reduced pressure is to the hot Process stream available deliver.</li></ul>

Of the first and second, can pressurized air flow through Compressing air and dividing the resultant Air flow into the first and a second pressurized air stream to disposal be provided. Alternatively, the first and second under Pressurized air flows by compressing air in a multistage air compressor, the removal of the compressed air from a final stage of the Compressor to a first pressurized airflow available to filters, and the removal of the compressed air from an intermediate stage of the compressor to a second pressurized air stream to disposal ask to receive. Alternatively, the first and second, pressurized air flows by compressing air in a first air compressor, a first pressurized airflow available to questions and compressing air in a second air compressor, a second pressurized air power available to ask, receive.

Of the oxygen-rich product stream can be used to a carbonaceous gasify the raw material, so that a synthesis gas is produced, the hydrogen and carbon monoxide, wherein a portion of the synthesis gas at least a portion of the fuel for the combustion device to disposal can provide.

The Separation of the first pressurized air stream in a oxygen-rich product stream and a nitrogen-rich byproduct stream can be achieved by cryogenic distillation. The nitrogen-rich Byproduct stream can prior to combining with the second pressurized Airflow is compressed. Optionally, a part of the work-producing expansion of the hot, pressurized be used gas stream resulting force work to electrical to produce energy.

The Decomposition of the first, under pressure set airflow in a oxygen-rich product stream and a nitrogen-rich byproduct stream is accomplished by cryogenic distillation, wherein the nitrogen-rich Byproduct stream before combining with the second pressurized set air stream can be compressed. Part of the force work can be used to produce electrical energy. As fuel for the Combustor of the gas turbine can natural gas or other fuels be used alone or in conjunction with synthesis gas.

A Gas turbine is the preferred compressor drive means for the air separation unit an integrated, combined Vergasungszyklus- (IGCC) process, in the coal or other carbonaceous material with oxygen gassed and the generated gas is cleaned, so that a low-sulfur Fuel gas yields. This fuel gas is fired directly into a used gas turbine which drives a generator to electric to generate power with reduced environmental emissions. The oxygen is produced by air separation at low temperature, with little or all of the supplied, asked compressed air by the compressor of the gas turbine available and the nitrogen-rich Exhaust gas compressed by the air separation system and into the incinerator introduced the gas turbine will.

in recent years have become very energy efficient gas turbines and they approach to 60% for combined Cycles that burn natural gas. This was accomplished by the use of excellent materials and coatings achieved the higher heating temperatures, tighter manufacturing tolerances, better versions of inline burners, staged combustion and large Frame or frame turbines designed specifically for energy production international requirements. These improvements in energy efficiency can however by decreasing output powers in certain conditions and of elevated Maintenance frequency to be accompanied, the availability of the gas turbine for the connected Operating reduced. Higher Operating temperatures of the turbine to increase the opportunity for contamination, said Problem with tighter tolerances in a new, highly efficient System is connected.

The Combustion device in a direct-fired gas turbine less flexible than the incinerator in an indirect fired gas turbine and may frequent Alterations and repairs to be subjected to on the spot. In Ascended Contamination level in the fuel can excessive pollution in the incinerator and cause the expansion turbine. Deterioration, the repair and overhaul the path of the hot Gas in the device (ie, the combustion device and requires the expansion turbine) is referred to as "non-regenerable" and can the ability a plant to meet long-term contractual commitments seriously compromise. The usual Practice to incorporate steam or water into the incinerator, to to reduce the emission of nitrogen oxides and the output power the turbine to increase, also reduces the working life of the components in the hot end.

it is a need in the industry to improve the availability and to prevent the deterioration of gas turbine systems, the are integrated with air separation units, while many of the new advantageous Design features of the gas turbine can be maintained. It is the Object of the present invention, the availability and reliability a gas turbine engine for to improve an air separation unit, while the cost for producing of oxygen through a novel integration of the gas turbine and the air separation unit are reduced.

The present invention provides also a device for the generation of oxygen available to the comprises the features of claim 17th

The The following is a description, by way of example only and with reference to the accompanying drawings of presently preferred embodiments of the invention.

in the drawings:

<figref idrefs="S26">1</figref> is a schematic flow diagram of a first embodiment the method of the present invention;

<figref idrefs="S27">2</figref> is a schematic flow diagram of a second embodiment the present invention;

<figref idrefs="S28">3</figref> is a schematic flow diagram of a third embodiment the present invention;

<figref idrefs="S29">4</figref> is a schematic flow diagram of a fourth embodiment the present invention;

<figref idrefs="S30">5</figref> is a graphical representation of the heat rate over the Turbine inlet temperature for the first embodiment the present invention;

<figref idrefs="S31">6</figref> is a graphical representation of the heat rate over the Turbine inlet temperature for the second embodiment the present invention; and

<figref idrefs="S32">7</figref> is a graphical representation of oxygen content in the gas from the Combustor over the turbine inlet temperature for the first and second embodiment, of the present invention.

On First embodiment the present invention is in <figref idrefs="S26">1</figref> illustrates the integration of a gas turbine engine with an air separation unit (ASU for Air Separation Unit) at elevated pressure shows. The ambient air in line<figref>1</figref> is in a multistage air compressor <figref>3</figref> compressed air with increased pressure in line <figref>5</figref> at 140-490 psia (965-3375 kPa) from the last Stage compressor and air having an average pressure in line <figref>7</figref> at 40-440 psia (275-3025 kPa) of an intermediate stage of the compressor is available to put. compressor<figref>3</figref> can an adiabatic or intercooled his machine. The air with increased Pressure in line <figref>5</figref> at 150 to 1200 ° F (65-650 ° C) is in a heat exchanger <figref>9</figref> by indirect heat exchange with the nitrogen-rich byproduct stream in line <figref>11</figref> (becomes later defined) cooled, so that in line <figref>13</figref> a cooled air feed stream at elevated pressure results. This air supply stream is in an air separation system <figref>15</figref> introduced, the the air in an oxygen product in line <figref>17</figref> with 80 to 99.8 vol .-% oxygen and nitrogen byproduct in line <figref>11</figref> With less than 4 vol .-% oxygen at a pressure in the range of 40 to 440 psia (275-3025 kPa) disassembled. The nitrogen byproduct in line<figref>11</figref> shall in the heat exchanger <figref>9</figref> heated, such as described above, a heated nitrogen-product in line <figref>18</figref> to disposal questions to which air at medium pressure line <figref>7</figref> combined is such that a combined gas stream in line <figref>19</figref> results. Typically, the molar flow ratio of the nitrogen byproduct in line <figref>18</figref> to air at an average pressure of line <figref>7</figref> in the Range 1 to 10

Of the combined gas stream in line <figref>19</figref> is in the heat exchanger <figref>21</figref> by indirect heat exchange with hot Combustion gas in line <figref>23</figref> (Defined later) is heated, that a hot, pressurized gas in line <figref>25</figref> at 1150 to 2600 o F (620 to 1425 ° C) and 40-440 psia (275-3025 kPa) results. This hot Gas stream through the gas turbine expander <figref>27</figref> to perform work expands to produce a force-work used directly is to the mechanically connected, multi-stage air compressor <figref>3</figref> to drive. Optionally, can be used a part of that force work to to drive an electrical generator (not shown). Of the Expander exhaust steam in line <figref>29</figref>, Located in the vicinity of the atmospheric And pressure is typically contains less than 15 parts by volume of oxygen, is if necessary, via management <figref>31</figref> combined with air, wherein the oxygen gas in line <figref>33</figref> with fuel from line <figref>35</figref> in the combustor <figref>37</figref> is burned, so that a hot Combustion gas stream in line <figref>23</figref> results, the combined the Gas stream in line <figref>19</figref> heated as previously described has been. chilled Final exhaust in line <figref>39</figref> is typically released into the atmosphere. The fuel in line <figref>35</figref> may be any gaseous, liquid be or solid carbonaceous fuel.

The name is, pressurized gas in line <figref>25</figref>That the propellant fluid for the The gas expansion turbine <figref>27</figref> to disposal is, contains typically a minimum of 85 vol .-% nitrogen, the balance being Oxygen and argon. Unlike the blowing fluid in a direct containing combustion gas turbine the hot, pressurized gas stream in line <figref>25</figref> no combustion products, wherein the gas expansion turbine <figref>27</figref> not the carbon dioxide, Sulfur oxides, water and other components in such combustion products are present, is exposed. This is an important advantage over the integrated gas turbine air separation systems according to the prior art that use direct-fired gas turbines.

The Oxygen product in line <figref>17</figref> can in the syngas generator <figref>41</figref> used be to fuel in line <figref>43</figref> to a synthesis gas product in line <figref>45</figref> convert the hydrogen and carbon monoxide contains. The fuel in line <figref>43</figref> and the fuel in line <figref>35</figref> may be the same be, for example, natural gas, or may have different carbonaceous Components such as liquid Hydrocarbons, petroleum residues, coke his or coal. If desired, synthesis gas in line<figref>45</figref> for the fuel in line <figref>35</figref> be used.

The Air separation system <figref>15</figref> is typically a cryogenic air separation system any type known to the prior art Art. After this embodiment includes air separation system <figref>15</figref> preferably a distillation system with increased Pressure, in a range from 140 to 490 psia (965-3375 kPa) is working. The nitrogen byproduct in line<figref>11</figref> requires typically no compression prior to combustion with the under Pressurized air stream in line <figref>7</figref>, Alternatively, the air separation system <figref>15</figref> a pressure swing adsorption (PSA) or a mixed ceramic pipe membrane method fired in connection with a described above, indirectly use gas turbine system. After such embodiments would be a alternative heat exchange and heat integration steps necessary because PSA process close the ambient temperatures and with ceramic mixed line membrane method at elevated Temperatures work. Each of these alternative embodiments but would use an indirect fired gas turbine.

On alternative embodiment the invention is in <figref idrefs="S27">2</figref> illustrated in which the supply air in compressor <figref>201</figref> is compressed to pressurized Air in line <figref>203</figref> to provide that in two separate streams in the Leitungn <figref>205</figref> and <figref>207</figref> is divided. The pressurized air in line <figref>205</figref> is a indirect heat exchange in the heat exchanger <figref>9</figref> cooled, so that the cooled, pressurized air <figref>13</figref> obtained as previously described has been. The air separation system<figref>209</figref> operates at lower Push as the air separation system <figref>15</figref> from <figref idrefs="S26">1</figref>, in which the byproduct nitrogen in line <figref>211</figref> before heating in heat exchangers <figref>9</figref> in the Nitrogen compressor <figref>213</figref> is compressed. The pressurized set air in line <figref>207</figref> passes through the flow control valve <figref>217</figref> and is with the heated, pressurized nitrogen byproduct in line <figref>219</figref> combined a combined gas stream in line <figref>19</figref> available to ask who in the heat exchanger <figref>21</figref> is heated, as previously described. The remaining features of the embodiment from <figref idrefs="S27">2</figref> are comparable to those of the embodiment of <figref idrefs="S26">1</figref> identical.

On Another embodiment the invention is in <figref idrefs="S28">3</figref> illustrated. After this embodiment the air <figref>301</figref> in compressor <figref>303</figref> compressed by pressurized air in line <figref>305</figref> available to provide that the nitrogen byproduct of line <figref>18</figref> combined is, so that a combined gas stream in line <figref>19</figref> to disposal is provided which in the heat exchanger <figref>21</figref> is heated, as previously described. This embodiment separates the compression performance the compressor <figref>3</figref>, Of the air separation system <figref>15</figref> among Pressurized air is available represents, from the compression power of the compressor <figref>301</figref>. the air pressurized in line <figref>305</figref> provides. Further features of the embodiment from <figref idrefs="S28">3</figref> are comparable to those of the embodiment of <figref idrefs="S26">1</figref> identical.

On Another alternative embodiment the invention is in <figref idrefs="S29">4</figref> illustrated. According to this embodiment be heating and the expansion of the nitrogen byproduct in line <figref>18</figref> and the pressurized air in line <figref>19</figref> performed separately. The two streams be in the heat exchanger <figref>401</figref> by indirect heat exchange with a hot Combustion gas stream in line <figref>402</figref> heated to a hot, under Pressurized air stream in line <figref>403</figref> and a hot, under Pressurized nitrogen byproduct stream in line <figref>405</figref> to disposal deliver. If desired, a part of the pressurized air in line <figref>207</figref> through the valve <figref>400</figref> introduced and with the nitrogen byproduct in line <figref>18</figref> combined will. The hot, expanding the pressurized air and the nitrogen byproduct streams in the gas expansion turbine <figref>407</figref> or. <figref>409</figref>, Of the Expander exhaust steam in line <figref>411</figref> is, optionally after Combined with additional, in line <figref>31</figref> supplied Air, in line <figref>413</figref> in the combustion device <figref>415</figref> introduced fuel <figref>35</figref> to burn, whereby the hot combustion gas stream in management <figref>402</figref> arises. The embodiment of<figref idrefs="S29">4</figref> shall used, when a conventional, air Launch Combustion process in the combustor <figref>415</figref> prefers becomes. The hot Combustion gas stream in line <figref>402</figref> is a higher surplus oxygen having as the hot combustion gas stream in management <figref>23</figref> the above-described embodiments. Other features the embodiment from <figref idrefs="S29">4</figref> are comparable to those of the embodiment of <figref idrefs="S26">1</figref> identical.

The common element of all embodiments of the invention, as described above, the insert is an indirectly heated Driving fluid into the gas expansion turbine, wherein the propellant fluid is a Combination of pressurized air from the compressor of the gas turbine and the nitrogen-rich byproduct gas from the air separation unit is. The hot Motive fluid contains no combustion products, which allow the gas expansion turbine the carbon dioxide to sulfur oxides, water and other components, are present in such combustion products, not exposed to is. This is an important advantage of the present invention over the integrated gas turbine air separation systems according to the prior art.

The availability a process unit is defined as the percentage of time defined in a predetermined period of time during which the process unit is operational. While the remaining percentage of time, the process unit for the Maintenance and for Repairs decommissioned. When two or more process units are integrated into an operating system, the entire availability of System by the lowest availability of the process units certainly. It is therefore desirable the performance of the single unit with the lowest availability to improve the overall availability of the integrated operating system to improve.

The availability a typical cryogenic air separation unit, other than the compressor system is greater than 99%. The availability a gas turbine is generally lower than that of a cryogenic air separation unit, and then the entire Availability an integrated gas turbine / air separation system by the availability the gas turbine system dictates. An indirect fired gas turbine is higher availability than that of a direct-fired gas turbine. Therefore an integrated, indirectly-fired gas turbine / air separation system of the present Invention has a higher availability have an integrated, direct-fired gas turbine / air separation system according to the prior art. It is in certain work situations important availability to maximize an integrated gas turbine / air separation system, for example in situations where downtime very expensive and the maintenance is difficult. In such situations, the use an indirect fired gas turbine with the air separation system, as described by the present invention, compared to the Use of a direct-fired gas turbine is preferred.

example 1

The Balance of heat and material was in a simulation of the integrated gas turbine / Air separation system of <figref idrefs="S26">1</figref> executed. The Air separation unit is a cryogenic distillation system Double Column at an elevated Pressure, as described in the document US-A-5081845, with an oxygen production capacity of 5000 tons of American per day (short tons per day - STPD) (4250 tons per day). The gas turbine unit has a pressure distribution of 12.3 to 1 with an intermediate air extract at a pressure distribution of 6.6 to 1. The incinerator <figref>37</figref> is fired with methane. A summary of the simulation is shown in Table 1 for an inlet temperature the expansion turbine from 1912 ° F (1044 ° C) presented.

example 2

The Simulation of Example 1 was measured using a cryogenic distillation system Double Column repeated based on a method as described in the publication US-A-5 081 845 has been described, but with a lower air supply pressure operates and an oxygen production capacity of 5000 short tons per day (STPD) has (4250 tons per day). A summary of Simulation in Table 2 for presented an inlet temperature of the expansion turbine of 2418 ° F (1326 ° C).

<img img-content="tb" img-format="tif" he="189" wi="125" file="00170001.tif" />

<img img-content="tb" img-format="tif" he="190" wi="118" file="00180001.tif" />

example 3

The Simulation of Example 1 was for other inlet temperatures the expansion turbine between 1100 ° F (590 ° C) and 1900 ° F (1040 ° C) repeated. The heat rate, by the input to the gas turbine combustor (BTU / h; Kj / h) divided by the gas turbine output at the shaft (KW) is defined, has been for The present invention at various inlet temperatures the expansion turbine determined. The heat rate is a measure of the system efficiency in converting thermal energy into mechanical energy with the units of BTU / KWH (KJ / KWH) wherein a low heat rate higher System efficiency corresponds. For the comparison with the present invention were heat rates a conventional, directly fired gas turbine system (GE 7FA), both for a simple cycle (without a steam generation system for heat recovery and a steam turbine), as well as a combined cycle (with a steam generation system for heat recovery and a steam turbine) determined.

in <figref idrefs="S30">5</figref> shall a graphical representation of the heat rate against the turbine inlet temperature for the above information presented. If for the present invention the inlet temperature is reduced absorbs the heat rate to which the system efficiency decreases. be Lower turbine inlet temperatures of less severe operating conditions for the heat exchanger <figref>21</figref> from <figref idrefs="S26">1</figref> accompanied. At temperatures above 1500 ° F (815 ° C) are typically Components of the heat exchanger required of ceramic or a special metal alloy, whereas at lower temperatures or more conventional materials versions the heat exchanger can be used. In the <figref idrefs="S30">5</figref> show information graphically illustrated that the system of the present invention in the heat rate advantageously with the conventional, direct-fired GE 7FA combined cycle system compare leaves. During the Cycle of the present invention, a heat exchanger with costly Ceramic, or a metal alloy for heating the turbine inlet gas to over require 1500 ° F (815 ° C) would, would the steam generator heat recovery and a steam turbine of the direct-fired, combined cycle system not mandatory. At low turbine inlet temperatures can be fired, the present invention advantageously in heat rate with the right GE 7FA system compare simple cycle (no steam cycle). In all cases would the availability of the system of the present invention may be higher than that of conventional direct-fired system.

example 4

Of the Comparison of Example 3 is by means of the air separation cycle in low pressure of Example 2 was repeated, with the results in <figref idrefs="S31">6</figref> to be introduced. The graphical representation heat rate against the inlet temperature is in this case an approximately less efficient system than that of Example 3, but the conclusions and comparisons of the present invention with the conventional direct-fired gas turbine system are the same.

example 5

The Simulations of examples <figref>1</figref> and <figref>2</figref> were used, around <figref idrefs="S32">7</figref> prepare, which is a graphical representation the oxygen content of the hot Combustion gas from the combustion device <figref>37</figref> (Electricity <figref>23</figref>) against the inlet temperature of the expansion turbine (stream <figref>25</figref>) represents. A minimum oxygen content in the exhaust of the combustion device from about 2 vol .-% is required to complete combustion the fuel in the combustion equipment to be ensured. At lower oxygen concentrations would be a catalytic combustion in the combustion device <figref>37</figref> required. The air separation cycle at elevated Pressure of Example 1 can with turbine inlet temperatures up 1800 ° F (980 ° C) without the Need for catalytic combustion are used. Of the Air separation cycle at low pressure of Example 2 can with Turbine inlet temperatures up to 2600 ° F (1425 ° C) without the need for catalytic combustion are used. <figref idrefs="S32">7</figref> is for design purposes useful, if the turbine inlet temperature is selected.

In order to the present invention uses an indirectly-fired gas turbine system, a compressed air supply for a to provide air separation system in applications available, where high availability is the driving means necessary. The invention integrates a indirectly-fired gas turbine with the air separation system for the production of oxygen with an efficient use of the nitrogen-rich By-product as part of the propellant gas for the indirectly heated gas turbine.

The This invention improves the availability and reliability of gas turbine drive means for air separation systems and is particularly useful in places, where an electric drive means for the air separation system not possible is. In such places, the industrially developed areas may be removed and where a reliable Electric power system is missing, this high availability of the integrated gas turbine / Air separation system particularly important. The invention is also for very large air separation systems useful, for the independent, electric motors and air compressors are not available.