CA2075290A1 - Process and device for generating mechanical energy - Google Patents
Process and device for generating mechanical energyInfo
- Publication number
- CA2075290A1 CA2075290A1 CA002075290A CA2075290A CA2075290A1 CA 2075290 A1 CA2075290 A1 CA 2075290A1 CA 002075290 A CA002075290 A CA 002075290A CA 2075290 A CA2075290 A CA 2075290A CA 2075290 A1 CA2075290 A1 CA 2075290A1
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- Prior art keywords
- steam
- exhaust gas
- gas
- combustion
- fuel
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
- C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
- C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
- C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
- F02C3/00—Gas-turbine plants characterised by the use of combustion products as the working fluid
- F02C3/20—Gas-turbine plants characterised by the use of combustion products as the working fluid using a special fuel, oxidant, or dilution fluid to generate the combustion products
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K23/00—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids
- F01K23/02—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled
- F01K23/06—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled combustion heat from one cycle heating the fluid in another cycle
- F01K23/10—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled combustion heat from one cycle heating the fluid in another cycle with exhaust fluid of one cycle heating the fluid in another cycle
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
- F02C3/00—Gas-turbine plants characterised by the use of combustion products as the working fluid
- F02C3/20—Gas-turbine plants characterised by the use of combustion products as the working fluid using a special fuel, oxidant, or dilution fluid to generate the combustion products
- F02C3/30—Adding water, steam or other fluids for influencing combustion, e.g. to obtain cleaner exhaust gases
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/02—Processes for making hydrogen or synthesis gas
- C01B2203/0205—Processes for making hydrogen or synthesis gas containing a reforming step
- C01B2203/0227—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step
- C01B2203/0233—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step the reforming step being a steam reforming step
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/06—Integration with other chemical processes
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/06—Integration with other chemical processes
- C01B2203/066—Integration with other chemical processes with fuel cells
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/08—Methods of heating or cooling
- C01B2203/0805—Methods of heating the process for making hydrogen or synthesis gas
- C01B2203/0811—Methods of heating the process for making hydrogen or synthesis gas by combustion of fuel
- C01B2203/0822—Methods of heating the process for making hydrogen or synthesis gas by combustion of fuel the fuel containing hydrogen
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/08—Methods of heating or cooling
- C01B2203/0805—Methods of heating the process for making hydrogen or synthesis gas
- C01B2203/0811—Methods of heating the process for making hydrogen or synthesis gas by combustion of fuel
- C01B2203/0827—Methods of heating the process for making hydrogen or synthesis gas by combustion of fuel at least part of the fuel being a recycle stream
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/12—Feeding the process for making hydrogen or synthesis gas
- C01B2203/1205—Composition of the feed
- C01B2203/1211—Organic compounds or organic mixtures used in the process for making hydrogen or synthesis gas
- C01B2203/1235—Hydrocarbons
- C01B2203/1241—Natural gas or methane
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E20/00—Combustion technologies with mitigation potential
- Y02E20/16—Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
- Y02P20/129—Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Health & Medical Sciences (AREA)
- Health & Medical Sciences (AREA)
- Inorganic Chemistry (AREA)
- Engine Equipment That Uses Special Cycles (AREA)
- Diaphragms For Electromechanical Transducers (AREA)
- Other Liquid Machine Or Engine Such As Wave Power Use (AREA)
- Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
- Hydrogen, Water And Hydrids (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Saccharide Compounds (AREA)
Abstract
The invention concerns a process for the continuous conversion of energy chemically bound in a starting fuel based on C-H
compounds into useful mechanical energy. For this purpose, a gas turbine is used, and in order to obtain a high mechanical efficiency combustion of at least part of the fuel is carried out with a fuel obtained from the starting fuel by means of an endothermic reaction, the reaction chamber being heated for the endothermic reaction either by means of compressed combustion air heated by the exhaust gases or by means of the hot exhaust gases themselves.
compounds into useful mechanical energy. For this purpose, a gas turbine is used, and in order to obtain a high mechanical efficiency combustion of at least part of the fuel is carried out with a fuel obtained from the starting fuel by means of an endothermic reaction, the reaction chamber being heated for the endothermic reaction either by means of compressed combustion air heated by the exhaust gases or by means of the hot exhaust gases themselves.
Description
The present invention relates to a process for generating mechanical energy as defined in the preamble to patent claim 1, and to an apparatus for carrying out this process.
In most thermal generating stations, in order to generate electrical energy, superheated steam is first produced in boilers by the combustion of fossil fuels; this superheated steam is expanded inside steam tu~bines and converted into mechanical energy thereby. The steam turbines are coupled to electrical generators, so that this mechanical energy is converted into electrical energy. The latter occurs at a level of efficiency that is clearly above 90~. In contrast to this, the degree of efficiency with which the energy that is chemically bound within the fuel that is used into mechanical energy is very modest, for the degree of efficiency of the turbines themselves amounts at most to 37% in the case of large turbines, and losses in the boiler must also be accepted. For this reason, in many instances, up to now only approximately 35~ of the heat that is liberated during combustion can be used effectively for the generation of electricity, whereas approximately 65~ of the waste heat is lost, or could only be used for heating purposes.
Recently, it has been possible to achieve a considerable increase in the overall degree of efficiency in that, in order to convert the thermal energy into mechanical energy, a combination of gas turbines and steam turbines is used, the hot combustion gases being first expanded in gas turbines, when the heat from the exhaust gases of these gas turbines is used to generate steam for the steam turbines. Additional possibilities for improvement are that~the expanded steam that flows out of a steam turbine is, in each instance, passed back into the combustion chamber of the preceding gas turbine, thereby generating a greater volume flow to drive the gas turbine. These measures have made it possible to increase the overall degree of efficiency of the conversion of thermal energy into mechanical energy to an order of magnitude of ,.; , ' .
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approximately 48 to 50% in the case of large generating facilities (above 50 MW).
A combined gas/steam turbine process of this kind is described, for example, in DE 33 31 153 Al. Conventional ~'flowing~ fuels, i.e., liquid or gaseous hydrocarbons, are used to generate the required hot combustion gases for gas turbines. In order to avoid the formation of nitrogen oxides to the greatest extent possible, the combustion chamber temperature is lowered by introducing some of the steam that is generated with the heat of the gas turbine exhaust gases into the combustion chamber. At a total power output of 300 MW, the degree of efficiency that can be achieved for this process is said to be 48~.
The journal VGB Kraftwerkstechnik [Power Station Technology], 66, No. 5, May 1988, pp. 451 - 458, describes a combined gas/steam turbine process that is used in conjunction with coal gasification. The combustible gas that is generated in the coal gasification process is burned in part with compressed air in a first combustion chamber after having been scrubbed. One part of the hot combustion gases that are generated by doing this is first used for superheating the steam for the coal gasification and for heating the allothermic coal gasification itselS, before these gases are expanded in a first gas turbine that, in its turn, drives a compressor for the required combustion air. The other part of the combustible gas that is produced during the coal gasification is burned in a second combustion chamber and immediately thereafter is expanded in a second gas turbine that is coupled to an additional compressor for the combustion air that is required in the second combustion chamber and to an electrical~generator to generate electrical energy. The expanded turbine exhaust gas from the second gas turbine is used for steam generation before being passed to the atmosphere together with the expanded exhaust gas from the first gas turbine (c~mpressor drive turbine). This steam is expanded in a ~team turbine that ' ~ ~ .
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lS similarly coupled to a generator, in order to generate electrical energy. After partial expansion, some of the steam is uncoupled from the steam turbine and then, after the previously discussed superheating by the combustion gases from the first combustion chamber, is used for coal gasification.
Coal is used as the initial fuel in these known systems, and this is made useable for a gas turbine process in that it is first gasified. This conversion is urgently required from the technical standpoint because of the ash fraction that is produced during combustion and that would destroy a gas turbine. In contrast to this, fuels that are based on hydrocarbon compounds can be in either liquid or gaseous form, contain no ash fraction and, for this reason, can be used directly in a combined gas/steam turbine process without any problem. A characteristic of these known systems is that the combustion gases move in two sub-flows that are initially completely independent of each other and are used for different sub-processes before they are used together to generate steam at the end of the process. The net degree of efficiency of this apparatus is said to be approximately 42%, with the internal energy requirement for carrying out the process amounting to approximately 7.5%.
Another combined gas/steam turbine process for generating electrical energy, in which, initially, coal gasification i6 carried out, is described in US 4,478,039. Here, the gas that is generated is burned under pressure in a combustion chamber. The resulting~hot combustion gases are then expanded in a gas turbine that drives an electrical generator and a compressor for compressing the combustion air. The expanded turbine exhaust gas is~addltionally used for heating the coal gasification plant and for~generating steam for the steam turbine process. The steam turbine also~drives an electrical generator. This document makes to~;reference to the use of starting fuels that are based on hydrocarbon compounds.
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ln addition, DE 37 40 86~ Al describes a process and an apparatus for recovering hydrogen, a gaseous initial fuel, i.e., a hydrocarbon compound, being converted in steam reformation to a gas that is enriched with and has an absolute heating value that is elevated relative to the mass flow of the initial fuel.
In this context, ~'absolute heat value" is not understood to be a unit of a heating value that is related to a unit of weight, as is usually the case. Rather, what is meant here is the total quantity of combustion heat that is contained in a specific quantity of the initial fuel, or in a quantity of the converted fuel, and which results through the endothermic conv~rsion of the same quantity of initial fuel. In the case of steam reformation, because of the steam fraction that is added during the conversion, the total quantity of the converted fuel is of necessity considerably enlarged relative to the origina} quantity of the starting fuel, so that the heat value that is based on weight is smaller than was previously the case, even through the quantity of heat released during the combustion of the converted fuel has become greater.
The crude gas that is produced by this process according to DE 37 40 865 A1 is treated in a purification stage (e.g. a pressure alternation absorption apparatus) in order to produce a pure hydrogen gas, in which the impurities ~e.g. CO, CO2, H20, non-converted hydrocarbons) are separated off and removed in the form of a flow of exhaust gas. This combustible flow of exhaust gas that, of necessity, also contains certain residual fractions of the hydrogen gas, is burned with compressed air after compression in a compressor to a higher pressure than combustion gas, e.g., in the~heating chamber of the indirectly heated steam reformer.
Because of the extensive separation of the hydrogen from the crude~gas, the absolute thermal value of the flow of exhaust gas from~the purification stage falls considerably, relative to the absolute thermal value of the crude gas, and still lies beneath .
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that of the starting fuel that is used. For this reason, in many instances it is necessary to burn a partial flow of the starting fuel directly at the same time, when the steam reformer is being heated. After heating the steam reformer, the resulting combustion exhaust gas is passed on, as a moderator gas, to lower the temperature in a combustion chamber in which a part flow of the starting fuel is burned with compressed air. The flow of combustion exhaust gases that emerges from this combustion chamber is then expanded in a gas turbine. The gas turbine provides the compressor drive energy that is required in this process, and also makes it possible to generate electrical energy by means of a generator that is connected to it.
In this known process, the conversion of the starting fuel is effected only because of the fact that the intention is to produce hydrogen that is required for any applications beyond the scope of this process. DE 37 40 865 A1 contains no indications to the effect that such an endothermic fuel conversion could also be advantageous, were the converted fuel to be burned subsequently for purposes of generating mechanical energy. The combustion of the converted fuel that is used in this known process is thus effected only to make use of a secondary product.
In this connection, it is important to emphasize that during the combustion only one part of the original combustible component originally contained in the converted fuel is present, because the hydrogen fraction that accounts for the major part of the absolute thermal value has to a large extent been separated off prior to this. For this reason, the purely theoretical ratio of the generated useable mechanical or electrical energy to the quantity of chemically bound energy contained in the starting fuel that is used, less than lo~, is extremely small.
EP 0 318 122 A2, that forms the generic concept, describes a process and an apparatus for generating mechanical energy from gaseous fuels, in which the mechanical energy, which can be used, . ~ .
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~or example, for generating electricity, is produced by means of a gas turbine alone. This gas turbine, which is provided in particular for a power range of 50-3000 KW, achieves an efficiency of approximately 42% relative to the thermal energy used (the lower thermal value). To this end, provision is made for the fact that combustion air is first compressed in a compressor. The compressed combustion air is then heated in an exhaust gas heat exchanger, passed through a first gas turbine, which drives only the compressor, partially expanded, and then passed to a combustion chamber, within which fuel is burned with this combustion air. The hot exhaust gas that results from this combustion drives a second gas turbine that supplies the mechanical energy that is actually useable. The exhaust gas that flows out of the second turbine, and which is still hot, is used to drive the exhaust gas heat exchanger that is used to heat the compressed combustion air.
Fina}ly, US 31 67 913 describes yet another apparatus, which incorporates a single combustion chamber that is arranged ahead of the compressor turbine, i.e., ahead of the high pressure stagé, of the turbine system. Such high pressure systems require that the combustion chambers be designed to handle high pressures.
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In addition, in order to increase the efficiency o~ the turbine, every~effort is made to achieve high combustion temperatures, with the result that more injurious substances result. Because of the great~compression of the combustion air, there are high temperatures~in~th- compressed combustion air, and these have to be taken~into account when the exhaust gas heat exchanger is being~designed. All of these factors increase not only the cost of the~apparatus~; they also downgrad~ the overall efficiency of the system.
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I~ is the task of the present invention to so develop a process and an apparatus of this kind that the efficiency of the conversion of the energy (lower thermal value) contained in a fuel that is based on C-H compounds into mechanical energy in small plants (50-3000 KW) is greater than 50%, and in large plants is at least 55%. In the following, the expression "efficiency" will always be understood to be the "mechanical"
efficiency, i.e., the ratio of the generated useable mechanical energy from the turbine to the energy of the starting fuel that is used (based on the lower thermal value ~u)~
With respect to this process, this problem has been solved by the distinguishing features of patent claim l. Advantageous developments of this process ~re distinguished by the features of the sub-claims 2 to 13. An installation according to the present inventio~ for carrying out this process incorporates the features set out in patent claim 14, and this can be configured more advantageously by using the distinguishing features set out in sub-claims 15 to 21.
An important innovative step is that the configuration that is known from EP 0 310 122 A2 has been supplemented by a reactor for an endothermic chemical reaction, in which the fuel that is used (starting fuel) is-converted into a higher value fuel that is ultimately burned with the compressed air from the compressor.
When this is done, the thermal energy for operating the reactor is preferably recovered from the exhaust gas heat of tha exhaust gases that flow out of the gas turbine in which the usable `
mechanical energy is produced. However, other flows of hot gas within the process can be used to heat the reactor. In the event that the exhaust gas is used for the reactor, this additionally cooled gas can be use, for example, in an exhaust gas heat exchanger in order to heat the compressed combustion air.
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. ' , s~ 1 ~ s~ j3 The conversion of the starting fuel means that, as in a heat pump, waste heat from the exhaust gas from the gas turbine or another flow of heat can, as it were, be raised to a higher "potential temperature level," so that this heat can b~ better used, technically speaking, than heat at a lower temperature.
This "raising" of the temperature level takes place in the form of an elevated absolute thermal value of the new fuel (e.g., H2 and C0) formed within the reactor from the original fuel ~e.g., natural gas).
The procedure and the apparatus according to the present invention make it possible to trap the waste heat that results in the process systematically and use it in an effective manner. In this connection, it is a particular advantage to carry out the endothermic reaction for generating the higher value fuel, which can be carried out in particular as steam reformation, e.g., from natural gas, at a comparatively low temperature. Normally, this steam reformation ls carried out at an industrial scale only at temperatures in the range of 780 - sOoC. According to the present invention, it is more expedient that an upper temperature limit of 760 c, or better still, of 700 or even 650-C, is not exceeded.
The disadvantage that with the lower temperature, one has to accept some downgrading of the conversion rate of the original fuel, which is to say an increase in the proportion of non-converted fuel, is more than made up for by the advantage of improved utilization of the waste heat from the gas turbine or the heat of another flow of hot gas from the process during reactor heating, and the reduction of the temperature of the f~esh steam that is required for the endothermic reaction. ~he reduced temperature level also entails advantages for the costs of a plant according to the present invention, for the thermal d-mands~ on the fuels that are used are lower than in the prior a:rt.
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Also of very great importance is the fact that the combustion of the fuel can be influenced, e.g., by injecting water or water steam into the system's combustion chamber or chambers such that nitrogen oxides are either not formed or else formed in very small quantities. The flame temperature is restricted to values of at most 1700C (adiabatic flame temperature~ and the inlet temperature into the gas turbine is kept to at most 1250-C, so that the operation of the process according to the present invention is possible in a particularly environmentally benign manner without the need for any costly nitrogen removal apparatus. All of this is made possible by the integration of the fuel conversion and the generation of mechanical energy from the heat that is liberated by the combustion of the fuel, as provided for by the present invention. This means that such effective utilization of the waste heat flow is possible that a degree of efficiency previously regarded as unachievable has been achieved. Typical values lie in the range of 50-70%, in which connection smaller facilities are to ~e placed in the lower range, and larger facilities are to be placed in the upper part of the range. The plants according to the present invention are particularly well suited for the decentralized, i.e., local, generation of electricity, and thus offer the additional advantage that losses caused by the transmission of energy over great distances and/or by the transformation of current can be largely avoided. In the case of large generating stations, these losses have been found to amount to approximately 10% of the electrical energy that is produced.
Two main variants are to be regarded as particularly preferred ~for the process according to the present invention. In one of these main variants, as has already been described heretofore, the compressed combustion air is heated in an exhaust gas heat exchanger prior to being introduced into the combustion chamber, the waste gas heat exchanger being supplied with the waste gas f~rom the gas turbine that produces the useable mechanical energy.
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It is preferred that this waste gas heat exchanger be configured as a recuperator.
The greater the quantity of heat per unit time that i5 to be exchanged within this recuperator, the more rapidly the construction volume of this heat exchanger aggregate increases.
In the case of major installations of the kind according to the present invention (in the power range from approximately 50-80 MW), the recuperator is extremely large in comparison to conventional system parts, and is correspondingly costly. For this reason the second main variant of the invention, in which there is no recuperator, is preferred for larger installations.
In the second main variant, the exhaust gas from the gas turbine is used for the production of steam, (optionally after heating the reactor for the fuel conversion). This steam is superheated by means of a flow of hot gas that is present in the process, and then expanded in a steam turbine in order to generate additional mechanical energy, as is known from the so-called "combined cycle" power stations. Certainly, the efficiency of the process in such major installations is somewhat lower than in a version of the installation according to the first main variant, but the installation costs are significantly lower.
The present invention will be described in greater detail below on the basis of examples shown in the drawings appended hereto.
These drawings show the following:
, Figure l:~a system with a recuperator;
~; ~ Figure 2:~a~system w1th a steam turbine.
; In~the~embodiment of the present invention that is shown in figure~l~combustion air is drawn in through a line 9, by a aompressor~;3a of a compressor unit 3 that also incorporates a second~compressor 3b. The compressed combustion air is subjected ,~ :
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to intermediate cooling in a cooler 4 and then compressed to a still higher pressure in a second compressor 3b. ~oth compressors 3a and 3b are coupled mechanically by way of the shafts 24, 25 to a compressor drive gas turbine unit 2. The compressed combustion air is passed from the second compressor 3b through a line 10 into an exhaust gas heat exchanger 8 that is configured as a recuperator and from there it passes through a line 11 into a first combustion chamber 5 after being heated by indirect heat exchange.
Some of the fuel that has been formed from a starting fuel by means of an endothermic reaction passes into the combustion chamber 5 through the fuel feed line 20, and this is then burned in the combustion chamber 5. The resulting hot gas mixture that, in addition to the combustion products, also contains excess combustion air, passes through the hot gas feed line 12 to the compressor drive gas turbine unit 2, where it is partially expanded while giving off the drive energy that is required for the compressor unit 3, and thus cools down somewhat when this is done. Then, this gas mixture, which is still hot, passes through the hot gas feed line 13 into a second combustion chamber 6, into which fuel is also introduced through a branch line off the fuel feed line 20, and is then burned with the excess air, so that the exhaust gas is once again brought to a higher temperature.
The hot exhaust gas that results from this combustion passes through a hot gas line 14 to a gas turbine 1 that generates useable mechanical energy and, after expansion, it passes from there through the exhaust gas line 15. The compressor drive gas turbine unit 2 and the gas turbine 1 can be arranged on a common shaft and, under some circumstances, can even be configured as a ~; singIe turbine aggregate in order to simplify the overall installation. It is also possible to have these driven in part ~ by the gas turbine 1 if there are several compressor ~tages.
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The adiabatic flame temperature can be kept below 1700-C, and the inlet temperature into the gas turbine 1 can be kept to approximately 1250', and in many instances at even lower values of up to 800-C, by injecting water or water steam, for example, into the combustion chambers S and 6; at these temperatures no noteable quantities of nitrogen oxides are formed. In this connection, the present invention also provides a major advantage in that the formation of nitrogen oxide can be significantly reduced in that, in place of the starting fuel, the converted fuel, which has a higher absolute thermal value, which results in the endothermic reaction, is burned in place of the starting fuel. This means that from the very beginning (depending on the air surplus) there is an adiabatic flame temperature that is 300 to 550-C lower than the adiabatic flame temperature during combustion of the starting fuel.
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It is also possible to burn the fuel that is introduced in a single combustion chamber 5, so that the combustion chamber 6 can be eliminated. When two combustion chambers are used, the measures aimed at reducing the flame temperatures can also be ~confined to the second combustion chamber 6, for the nitrogen oxides that are formed in the first combustion chamber will be decomposed to a very great extent by the effect of heat during the subsequent second combustion. This means that, in the first combustion, work can be done with higher exhaust gas temperatures and, because of this, under favourable conditions for the compressor drive gas turbine with respect to the highest possible turblne~efficiency, without this ultimately leading to higher N0 contents.~ The controlled temperature management is thus of particular~importance in the first instance for the last combust~ion~stage.
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Ihe mechanical energy that lS produced during expansion withln the turbine 1 is available for use on the output shaft 26 and can be used, for example, to drive a generator 6 to produce electrical current. The exhaust gas that has been cooled somewhat during expansion, but which is still hot, passes through the exhaust gas line 15 into the hot area of the indirectly heated reactor 7 for the endothermic reaction. `
Because of this endothermic reaction, which can take place as steam reformation, for example, a new fuel with an elevated absolute thermal value is generated from the starting fuel that has a specific absolute thermal value. For the case of steam reformation from natural gas that is introduced, for example, through the fuel feed line 18, a steam feed 19 leading into the reaction space of the reactor 7 is shown.
As a rule, it is useful to mix the steam with the fuel before this. The new fuel that is generated, which consists of a mixture of H2, C0, C02 non-converted CH4 and steam, is passed along the feed line 20 from the reaction chamber and into the combustion chambers 5 and 6, where it is burned, as described above. It is, of course, also possible to mix part of the starting fuel into the higher-value fuel in order to optimize the combustion processes (temperature, mass flow) within the combustion chambers 5 and 6. When this is done, it is most expedient to use a mixture with at least 50~, and preferably even more than 60% of the unconverted fuel. The smaller the amount of unconverted fuel that is contained, the more the efficiency will be réduced, according to tendency. The principle to the effect that--taken all in all--the fuel that is burned has a higher thermal-value than the starting fuel, is maintained in each case.
Some of~the higher value fuel can, of course, be decoupled from the process and used in other processes.
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During the steam reformation of natural gas (essentially CH4) that has been discussed above, the absolute thermal value of the fuel is increased by approximately 30~. In the case of hydrogenation of the starting fuel--toluol--the thermal value increase amounts to approximately 15~. In place of steam reformation, the endothermic reaction can be in the form of de-hydrogenation, for example. In the case of ethane as a starting fuel, this would result in a thermal value increase of approximately 10-20%, and in the case of methanol by approximately 20-30%. A further example for an endothermic reaction is the steam cracking of some hydrocarbon compounds (e.g., biogas, LPG, naphtha and kerosene).
This last-named possibility is interesting because it permits the alternating utilization of a number of different fuels to generate the mechanical energy, without the gas turbine having to be adjusted for a new fuel each time a different fuel is used.
The endothermic reaction is, as far as possible, to be carried out at temperatures below 780C or be~ter still, below 700-C.
The exhaust gas that is used for heating leaves the hot area of the reactor 7 through the exhaust gas line 16, when it i5 still at a relatively high temperature and, according to the present invention, is used, for example, for heating the exhaust gas heat exchanger 8, with which the ~ompressed combustion air is heated.
Finally, the cooled gas passes out of the exhaust gas heat exchanger through the exhaust gas line 17.
In the case of an endothermic reaction in which the use of steam is necessary, the process according to the present invention can be operated as a closed system insofar as this steam can be generated by using the heat that is available in the individual hot volume flows. In order to achieve an even higher overall efficiency for the process, at least one part of the reguired fresh steam can also be introduced from any ~team source, from ' .
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outside the reactor 7. In the lay-out diagra~, steam generators 21, 22, 23 have been drawn in with dashed lines at the locations in question as options, and these can be operated alternatively or simultaneously. The steam generator 21 is installed at the end of the system, in the exhaust gas line 17, and for this reason can only generate steam of a relatively low temperature.
A heat exchanger that is used to pre-heat the starting fuel (or a fuel/steam mixture) or to pre-heat the feed water for the steam generator could also be installed at this point.
A further possible place for the steam generator 22 is between the exhaust gas heat exchanger 8 and the reactor 7 in the exhaust gas line 16.
A preferred arrangement is to incorporate the steam generator 23 between the compressor drive gas turbine unit 2 and the second combustion chamber 6, for this arrangement has a positive effect in the sense of reducing the combustion temperature in the combustion chamber 6. If a plurality of steam generators 21 to ~23 i8 installed at the same time, these can be so arranged one behind the other that one (for example 21) generates steam at a relatively low temperature, and this steam i8 then superheated to a higher temperature in another (e.g. 22 and/or 23).
Fundamentally, the waste heat that occurs as a result of intèrmediate~cooling during compres~sion of the combustion air can be used in the cooler 4 to generate steam.
In the~ lay-out diagram shown in figure 1, the reactor 7 is installed in~the exhaust gas line 15, 16 of the gas turbine 1.
Nowever, it is also possible to provide for reactor heating with a~flow of~hot gas that is produced earlier in the process. For this~reason, the~reactor 7 could, in principle, be incorporated in the~lines 11, 12~, 13, or 14. Because of a temperature reduction~;in the~hot~gas flow, the turbine efficiency of the turbines ~I, or~2~r-apaot~valy, is reduced but, however~ NO~
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formation is also reduced at the same time. For this reason, the process parameters must be matched to each other in order to achieve the optimal effect.
In order to make it possible to start the system up from cold, when neither a hot gas flow nor sufficient converted fuel are available for use, as an alternative or simultaneously, provision can be made for the fact that the original fuel (e.g., natural gas) can be introduced in the combustion chamber 5 and the hot area of the reactor 7 and there burned, at least on a temporary basis.
The corresponding separate fuel feed lines (not shown herein) can be switched on briefly should the thermal output that is available in these aggregates be momentarily inadequate. Because of this, the overall operation of the installation is extremely simple to control. In addition, in order to provide better control and to optimize the overall system, provision can also be made for some of the energy produced in the gas turbine 2 for the compressor drive to be utilized as useable mechanical energy outside the system.
Figure 2 is a schematic representation of the second main variant of the process according to the present invention. In this drawing, components of the system that perform the same functions as in figure 1 bear the same reference numbers as in figure 1.
For this reason, the statements made with respect to figure 1 apply to figure 2 as well, so that only the differences between the two variants will be discussed in greater detail below.
The essential difference compared to figure 1 is the fact that the heat exchanger 8, which is configured as a recupterator for pre-heating the combustion air, has been eliminated, and in place of this there is a system to generate superheated steam that is used in a steam turbine 31 in order to produce mechanical energy.
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This steam generating system consists of a boiler 30 and a steam superheater 28.
The steam boiler 30 is heated with the residual heat from the exhaust gases that leave the gas turbine 1, once these gases have passed through the heating chamber of the reactor 7 and given up additional heat in so doing. The steam that is generated passes through the line 37 to the superheater 29 and from there through the line 38 to the steam inlet side of the steam turbtne 31. The expanded steam passes from the steam turbine 31 into a condenser 32. The condensate pump 33 delivers the condensed water into a de-gassing apparatus 34.
From there, the prepared boiler water is moved by the boiler feed pump 35 through a line into the boiler 30. Thus, the steam/water system is a largely closed circulatory system. Water losses that take place are made up by a water feed system (not shown herein).
These water losses occur, in particular, when, as is shown in fi~ure 2 by a dashed line 36, steam is decoupled from the high pressure section of the steam turbine 31 and introduced into the combustion chambers 5 and 6 to control the temperature and increase the mass flow. The line 19, which is also optional, can decouple steam from the circulating system in the same way and introduce this into the reaction chamber of the reactor 7.
However, this steam could be generated in another part of the system, as has already been discussed in connection with figure 1, or else supplied from outside the system. The water that is required to replenish the steam/water circulation system can be obtained by recovering condensate from the exhaust gas line 17.
For purposes of completeness, it should be mentioned that the feed line for introducing th~ compressed combustion air into the first combustion chamber 5 in figure 2 is numbered 27 and the hot gas line from the steam superheater 29 to the second combustion : .-, : . . : - , . ~ . :, , . ' - :, ' '. .. . .:, . :.- ~ .
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chamber 6 is numbered 28. In principle, the fact that the reactor 7 can be incorporated at another location in the hot gas lines also applies to the process variant that is shown in figure 2. A preferred solution for this is that the positions of the reactor 7 and of the steam superheater 2~ can be exchanged with each other.
A further advantageous configuration of the present in~ention (not shown in figures 1 and 2) relates to the utilization of the hot exhaust gas that is expanded in the gas turbine 1. In the normal course of events, this exhaust gas still contains a considerable 2 content because combustion is effected with an excess of 2- For this reason, this can be used, for example, as a cathode gas for the 2 supply of a fuel cell system in which electrical current is generated.
In fuel cell systems of this type, it is advantageous that cathode gas be introduced at a temperature that corresponds to the operating temperature of the fuel cells. Depending on the type of fuel cell system, the operating temperature lies at another level. Accordingly, the fuel cell system i9 incorporated at a suitable point in the exhaust gas line 15, 16, 17, i.e., the cooling of the expanded exhaust gas during heating of other media flows that are required in the process according tc the present invention (air pre-heating, steam generation, reformer heating) is carried out approximately up to the level that corresponds to the operating temperature that is desired in each instance, and then the flow of exhaust gas or a part thereof is introduced into the cathode chamber of the fuel cell system. The fuel cell system can be supplied with fuel by any H2 gas source (e.g., pipeline or gas accumulator). A partial flow of a gas enriched with H2, produced in the reactor 7, could also be introduced into the anode chamber of the fuel cell system.
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The effectiveness of the process according to the present invention is described in greater detail below, on the basis o~
an embodiment. A system diagram that corresponds to figure 1 has been used in order to do this. The heat exchanger 21 was used to generate steam and to pre-heat natural gas, whereas the heat exchanger 22 served to superheat the steam/natural gas mixture, before this mixture was passed to the steam reformer 7. The natural gas that was used as the starting fuel was at a line pressure of 20 bar and the water that was used was at a temperature of approximately 15C. The steam~carbon [sic] ratio (mol/mol) amounted to 2Ø For the remainder, the process parameters were selected in accordance with the following tabular compilation. In the interests of clarity, the same reference numbers are used here as in figure 1.
- Low pressure compressor (3a) inlet temperature 15 D C
Outlet temperature 1~0C
Outlet pressure 4.5 bar - High pressure compressor (3b) inlet temperature 25C
Outlet temperature 203~C
Outlet pressure 20 bar - Recuperator (8) Temperature rise in the combustion air 357C
Temperature drop of the exhaust gas 327C
- Combustion chamber (5) Temperature rise during combustion 6~0C
- Compressor drive turbine (2) Inlet temperature 1250C
Pressure ratio at the turbine 2.8 Outlet temperature 970-- Combustion chamber (6) Temperature rise during combustion 280OC
- Gas turbine (1) Inlet temperature 1250'C
Pressure ratio at the gas turbine 6.4 ' ~- ' ' .
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- Generator (6) to generate electrical currPnt; power output 3200 KW~
- Steam reformer (7) Inlet temperature of superheated fuel/
steam mixture 550 C
Outlet temperature of the exhaust gas 647 C
Outlet temperature of the product gas 720-C
- Fuel/steam superheater (22) Inlet temperature fuel/steam mixture 249 C
Outlet temperature of the exhaust gas 610 n C
- Fuel pre-heater/steam generator (21) Outlet temperature of the exhaust gas 227-C
During the steam reformation of the natural gas that consists essentially of methane, some 12~ of the methane fraction was not converted and was burned in the combustion chambers 5 and 6 in its original form. With the exception of the energy for compression of the natural gas, which was available at sufficient line pressure, the total energy requirement for the process was covered by the process itself, so that there was no additional energy brought in from outside the system. The overall efficiency achieved thereby, i.e., the ratio of the generated electrical energy to the quantity of energy used from fuel on th~
basis of the lower thermal value amounted to 65%, and was thus was at an order of magnitude not previously achieved. When this was done, the exhaust gas that was discharged into the environment was characterized by a very low content of nitrogen oxides, without any additional nitrogen removel measures being required in order to achieve this.
The major advantage that is achieved by the present invention is the fact that it not only makes possible a drastic increase in efficiency during the generation of mechanical energy, using fuels that are based on hydrocarbon compounds, but also the fact .
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that this can be connected with a reduction in the content of injurious substances in the exhaust gas that i5 generated. In addition, there is the fact that, because of the special suitability of systems according to the present invention for decentralized generation of electricity, the losses that are incurred by moving electrical energy over long distances, using conventional technology of the sort found in large generating stations, and during the transformation of the current, are largely avoided.
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In most thermal generating stations, in order to generate electrical energy, superheated steam is first produced in boilers by the combustion of fossil fuels; this superheated steam is expanded inside steam tu~bines and converted into mechanical energy thereby. The steam turbines are coupled to electrical generators, so that this mechanical energy is converted into electrical energy. The latter occurs at a level of efficiency that is clearly above 90~. In contrast to this, the degree of efficiency with which the energy that is chemically bound within the fuel that is used into mechanical energy is very modest, for the degree of efficiency of the turbines themselves amounts at most to 37% in the case of large turbines, and losses in the boiler must also be accepted. For this reason, in many instances, up to now only approximately 35~ of the heat that is liberated during combustion can be used effectively for the generation of electricity, whereas approximately 65~ of the waste heat is lost, or could only be used for heating purposes.
Recently, it has been possible to achieve a considerable increase in the overall degree of efficiency in that, in order to convert the thermal energy into mechanical energy, a combination of gas turbines and steam turbines is used, the hot combustion gases being first expanded in gas turbines, when the heat from the exhaust gases of these gas turbines is used to generate steam for the steam turbines. Additional possibilities for improvement are that~the expanded steam that flows out of a steam turbine is, in each instance, passed back into the combustion chamber of the preceding gas turbine, thereby generating a greater volume flow to drive the gas turbine. These measures have made it possible to increase the overall degree of efficiency of the conversion of thermal energy into mechanical energy to an order of magnitude of ,.; , ' .
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approximately 48 to 50% in the case of large generating facilities (above 50 MW).
A combined gas/steam turbine process of this kind is described, for example, in DE 33 31 153 Al. Conventional ~'flowing~ fuels, i.e., liquid or gaseous hydrocarbons, are used to generate the required hot combustion gases for gas turbines. In order to avoid the formation of nitrogen oxides to the greatest extent possible, the combustion chamber temperature is lowered by introducing some of the steam that is generated with the heat of the gas turbine exhaust gases into the combustion chamber. At a total power output of 300 MW, the degree of efficiency that can be achieved for this process is said to be 48~.
The journal VGB Kraftwerkstechnik [Power Station Technology], 66, No. 5, May 1988, pp. 451 - 458, describes a combined gas/steam turbine process that is used in conjunction with coal gasification. The combustible gas that is generated in the coal gasification process is burned in part with compressed air in a first combustion chamber after having been scrubbed. One part of the hot combustion gases that are generated by doing this is first used for superheating the steam for the coal gasification and for heating the allothermic coal gasification itselS, before these gases are expanded in a first gas turbine that, in its turn, drives a compressor for the required combustion air. The other part of the combustible gas that is produced during the coal gasification is burned in a second combustion chamber and immediately thereafter is expanded in a second gas turbine that is coupled to an additional compressor for the combustion air that is required in the second combustion chamber and to an electrical~generator to generate electrical energy. The expanded turbine exhaust gas from the second gas turbine is used for steam generation before being passed to the atmosphere together with the expanded exhaust gas from the first gas turbine (c~mpressor drive turbine). This steam is expanded in a ~team turbine that ' ~ ~ .
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lS similarly coupled to a generator, in order to generate electrical energy. After partial expansion, some of the steam is uncoupled from the steam turbine and then, after the previously discussed superheating by the combustion gases from the first combustion chamber, is used for coal gasification.
Coal is used as the initial fuel in these known systems, and this is made useable for a gas turbine process in that it is first gasified. This conversion is urgently required from the technical standpoint because of the ash fraction that is produced during combustion and that would destroy a gas turbine. In contrast to this, fuels that are based on hydrocarbon compounds can be in either liquid or gaseous form, contain no ash fraction and, for this reason, can be used directly in a combined gas/steam turbine process without any problem. A characteristic of these known systems is that the combustion gases move in two sub-flows that are initially completely independent of each other and are used for different sub-processes before they are used together to generate steam at the end of the process. The net degree of efficiency of this apparatus is said to be approximately 42%, with the internal energy requirement for carrying out the process amounting to approximately 7.5%.
Another combined gas/steam turbine process for generating electrical energy, in which, initially, coal gasification i6 carried out, is described in US 4,478,039. Here, the gas that is generated is burned under pressure in a combustion chamber. The resulting~hot combustion gases are then expanded in a gas turbine that drives an electrical generator and a compressor for compressing the combustion air. The expanded turbine exhaust gas is~addltionally used for heating the coal gasification plant and for~generating steam for the steam turbine process. The steam turbine also~drives an electrical generator. This document makes to~;reference to the use of starting fuels that are based on hydrocarbon compounds.
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ln addition, DE 37 40 86~ Al describes a process and an apparatus for recovering hydrogen, a gaseous initial fuel, i.e., a hydrocarbon compound, being converted in steam reformation to a gas that is enriched with and has an absolute heating value that is elevated relative to the mass flow of the initial fuel.
In this context, ~'absolute heat value" is not understood to be a unit of a heating value that is related to a unit of weight, as is usually the case. Rather, what is meant here is the total quantity of combustion heat that is contained in a specific quantity of the initial fuel, or in a quantity of the converted fuel, and which results through the endothermic conv~rsion of the same quantity of initial fuel. In the case of steam reformation, because of the steam fraction that is added during the conversion, the total quantity of the converted fuel is of necessity considerably enlarged relative to the origina} quantity of the starting fuel, so that the heat value that is based on weight is smaller than was previously the case, even through the quantity of heat released during the combustion of the converted fuel has become greater.
The crude gas that is produced by this process according to DE 37 40 865 A1 is treated in a purification stage (e.g. a pressure alternation absorption apparatus) in order to produce a pure hydrogen gas, in which the impurities ~e.g. CO, CO2, H20, non-converted hydrocarbons) are separated off and removed in the form of a flow of exhaust gas. This combustible flow of exhaust gas that, of necessity, also contains certain residual fractions of the hydrogen gas, is burned with compressed air after compression in a compressor to a higher pressure than combustion gas, e.g., in the~heating chamber of the indirectly heated steam reformer.
Because of the extensive separation of the hydrogen from the crude~gas, the absolute thermal value of the flow of exhaust gas from~the purification stage falls considerably, relative to the absolute thermal value of the crude gas, and still lies beneath .
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that of the starting fuel that is used. For this reason, in many instances it is necessary to burn a partial flow of the starting fuel directly at the same time, when the steam reformer is being heated. After heating the steam reformer, the resulting combustion exhaust gas is passed on, as a moderator gas, to lower the temperature in a combustion chamber in which a part flow of the starting fuel is burned with compressed air. The flow of combustion exhaust gases that emerges from this combustion chamber is then expanded in a gas turbine. The gas turbine provides the compressor drive energy that is required in this process, and also makes it possible to generate electrical energy by means of a generator that is connected to it.
In this known process, the conversion of the starting fuel is effected only because of the fact that the intention is to produce hydrogen that is required for any applications beyond the scope of this process. DE 37 40 865 A1 contains no indications to the effect that such an endothermic fuel conversion could also be advantageous, were the converted fuel to be burned subsequently for purposes of generating mechanical energy. The combustion of the converted fuel that is used in this known process is thus effected only to make use of a secondary product.
In this connection, it is important to emphasize that during the combustion only one part of the original combustible component originally contained in the converted fuel is present, because the hydrogen fraction that accounts for the major part of the absolute thermal value has to a large extent been separated off prior to this. For this reason, the purely theoretical ratio of the generated useable mechanical or electrical energy to the quantity of chemically bound energy contained in the starting fuel that is used, less than lo~, is extremely small.
EP 0 318 122 A2, that forms the generic concept, describes a process and an apparatus for generating mechanical energy from gaseous fuels, in which the mechanical energy, which can be used, . ~ .
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~or example, for generating electricity, is produced by means of a gas turbine alone. This gas turbine, which is provided in particular for a power range of 50-3000 KW, achieves an efficiency of approximately 42% relative to the thermal energy used (the lower thermal value). To this end, provision is made for the fact that combustion air is first compressed in a compressor. The compressed combustion air is then heated in an exhaust gas heat exchanger, passed through a first gas turbine, which drives only the compressor, partially expanded, and then passed to a combustion chamber, within which fuel is burned with this combustion air. The hot exhaust gas that results from this combustion drives a second gas turbine that supplies the mechanical energy that is actually useable. The exhaust gas that flows out of the second turbine, and which is still hot, is used to drive the exhaust gas heat exchanger that is used to heat the compressed combustion air.
Fina}ly, US 31 67 913 describes yet another apparatus, which incorporates a single combustion chamber that is arranged ahead of the compressor turbine, i.e., ahead of the high pressure stagé, of the turbine system. Such high pressure systems require that the combustion chambers be designed to handle high pressures.
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In addition, in order to increase the efficiency o~ the turbine, every~effort is made to achieve high combustion temperatures, with the result that more injurious substances result. Because of the great~compression of the combustion air, there are high temperatures~in~th- compressed combustion air, and these have to be taken~into account when the exhaust gas heat exchanger is being~designed. All of these factors increase not only the cost of the~apparatus~; they also downgrad~ the overall efficiency of the system.
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I~ is the task of the present invention to so develop a process and an apparatus of this kind that the efficiency of the conversion of the energy (lower thermal value) contained in a fuel that is based on C-H compounds into mechanical energy in small plants (50-3000 KW) is greater than 50%, and in large plants is at least 55%. In the following, the expression "efficiency" will always be understood to be the "mechanical"
efficiency, i.e., the ratio of the generated useable mechanical energy from the turbine to the energy of the starting fuel that is used (based on the lower thermal value ~u)~
With respect to this process, this problem has been solved by the distinguishing features of patent claim l. Advantageous developments of this process ~re distinguished by the features of the sub-claims 2 to 13. An installation according to the present inventio~ for carrying out this process incorporates the features set out in patent claim 14, and this can be configured more advantageously by using the distinguishing features set out in sub-claims 15 to 21.
An important innovative step is that the configuration that is known from EP 0 310 122 A2 has been supplemented by a reactor for an endothermic chemical reaction, in which the fuel that is used (starting fuel) is-converted into a higher value fuel that is ultimately burned with the compressed air from the compressor.
When this is done, the thermal energy for operating the reactor is preferably recovered from the exhaust gas heat of tha exhaust gases that flow out of the gas turbine in which the usable `
mechanical energy is produced. However, other flows of hot gas within the process can be used to heat the reactor. In the event that the exhaust gas is used for the reactor, this additionally cooled gas can be use, for example, in an exhaust gas heat exchanger in order to heat the compressed combustion air.
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. ' , s~ 1 ~ s~ j3 The conversion of the starting fuel means that, as in a heat pump, waste heat from the exhaust gas from the gas turbine or another flow of heat can, as it were, be raised to a higher "potential temperature level," so that this heat can b~ better used, technically speaking, than heat at a lower temperature.
This "raising" of the temperature level takes place in the form of an elevated absolute thermal value of the new fuel (e.g., H2 and C0) formed within the reactor from the original fuel ~e.g., natural gas).
The procedure and the apparatus according to the present invention make it possible to trap the waste heat that results in the process systematically and use it in an effective manner. In this connection, it is a particular advantage to carry out the endothermic reaction for generating the higher value fuel, which can be carried out in particular as steam reformation, e.g., from natural gas, at a comparatively low temperature. Normally, this steam reformation ls carried out at an industrial scale only at temperatures in the range of 780 - sOoC. According to the present invention, it is more expedient that an upper temperature limit of 760 c, or better still, of 700 or even 650-C, is not exceeded.
The disadvantage that with the lower temperature, one has to accept some downgrading of the conversion rate of the original fuel, which is to say an increase in the proportion of non-converted fuel, is more than made up for by the advantage of improved utilization of the waste heat from the gas turbine or the heat of another flow of hot gas from the process during reactor heating, and the reduction of the temperature of the f~esh steam that is required for the endothermic reaction. ~he reduced temperature level also entails advantages for the costs of a plant according to the present invention, for the thermal d-mands~ on the fuels that are used are lower than in the prior a:rt.
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Also of very great importance is the fact that the combustion of the fuel can be influenced, e.g., by injecting water or water steam into the system's combustion chamber or chambers such that nitrogen oxides are either not formed or else formed in very small quantities. The flame temperature is restricted to values of at most 1700C (adiabatic flame temperature~ and the inlet temperature into the gas turbine is kept to at most 1250-C, so that the operation of the process according to the present invention is possible in a particularly environmentally benign manner without the need for any costly nitrogen removal apparatus. All of this is made possible by the integration of the fuel conversion and the generation of mechanical energy from the heat that is liberated by the combustion of the fuel, as provided for by the present invention. This means that such effective utilization of the waste heat flow is possible that a degree of efficiency previously regarded as unachievable has been achieved. Typical values lie in the range of 50-70%, in which connection smaller facilities are to ~e placed in the lower range, and larger facilities are to be placed in the upper part of the range. The plants according to the present invention are particularly well suited for the decentralized, i.e., local, generation of electricity, and thus offer the additional advantage that losses caused by the transmission of energy over great distances and/or by the transformation of current can be largely avoided. In the case of large generating stations, these losses have been found to amount to approximately 10% of the electrical energy that is produced.
Two main variants are to be regarded as particularly preferred ~for the process according to the present invention. In one of these main variants, as has already been described heretofore, the compressed combustion air is heated in an exhaust gas heat exchanger prior to being introduced into the combustion chamber, the waste gas heat exchanger being supplied with the waste gas f~rom the gas turbine that produces the useable mechanical energy.
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It is preferred that this waste gas heat exchanger be configured as a recuperator.
The greater the quantity of heat per unit time that i5 to be exchanged within this recuperator, the more rapidly the construction volume of this heat exchanger aggregate increases.
In the case of major installations of the kind according to the present invention (in the power range from approximately 50-80 MW), the recuperator is extremely large in comparison to conventional system parts, and is correspondingly costly. For this reason the second main variant of the invention, in which there is no recuperator, is preferred for larger installations.
In the second main variant, the exhaust gas from the gas turbine is used for the production of steam, (optionally after heating the reactor for the fuel conversion). This steam is superheated by means of a flow of hot gas that is present in the process, and then expanded in a steam turbine in order to generate additional mechanical energy, as is known from the so-called "combined cycle" power stations. Certainly, the efficiency of the process in such major installations is somewhat lower than in a version of the installation according to the first main variant, but the installation costs are significantly lower.
The present invention will be described in greater detail below on the basis of examples shown in the drawings appended hereto.
These drawings show the following:
, Figure l:~a system with a recuperator;
~; ~ Figure 2:~a~system w1th a steam turbine.
; In~the~embodiment of the present invention that is shown in figure~l~combustion air is drawn in through a line 9, by a aompressor~;3a of a compressor unit 3 that also incorporates a second~compressor 3b. The compressed combustion air is subjected ,~ :
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to intermediate cooling in a cooler 4 and then compressed to a still higher pressure in a second compressor 3b. ~oth compressors 3a and 3b are coupled mechanically by way of the shafts 24, 25 to a compressor drive gas turbine unit 2. The compressed combustion air is passed from the second compressor 3b through a line 10 into an exhaust gas heat exchanger 8 that is configured as a recuperator and from there it passes through a line 11 into a first combustion chamber 5 after being heated by indirect heat exchange.
Some of the fuel that has been formed from a starting fuel by means of an endothermic reaction passes into the combustion chamber 5 through the fuel feed line 20, and this is then burned in the combustion chamber 5. The resulting hot gas mixture that, in addition to the combustion products, also contains excess combustion air, passes through the hot gas feed line 12 to the compressor drive gas turbine unit 2, where it is partially expanded while giving off the drive energy that is required for the compressor unit 3, and thus cools down somewhat when this is done. Then, this gas mixture, which is still hot, passes through the hot gas feed line 13 into a second combustion chamber 6, into which fuel is also introduced through a branch line off the fuel feed line 20, and is then burned with the excess air, so that the exhaust gas is once again brought to a higher temperature.
The hot exhaust gas that results from this combustion passes through a hot gas line 14 to a gas turbine 1 that generates useable mechanical energy and, after expansion, it passes from there through the exhaust gas line 15. The compressor drive gas turbine unit 2 and the gas turbine 1 can be arranged on a common shaft and, under some circumstances, can even be configured as a ~; singIe turbine aggregate in order to simplify the overall installation. It is also possible to have these driven in part ~ by the gas turbine 1 if there are several compressor ~tages.
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- - - - - : - -qnis makes it possible to achieve an optimal match of the compressor and the turbines.
The adiabatic flame temperature can be kept below 1700-C, and the inlet temperature into the gas turbine 1 can be kept to approximately 1250', and in many instances at even lower values of up to 800-C, by injecting water or water steam, for example, into the combustion chambers S and 6; at these temperatures no noteable quantities of nitrogen oxides are formed. In this connection, the present invention also provides a major advantage in that the formation of nitrogen oxide can be significantly reduced in that, in place of the starting fuel, the converted fuel, which has a higher absolute thermal value, which results in the endothermic reaction, is burned in place of the starting fuel. This means that from the very beginning (depending on the air surplus) there is an adiabatic flame temperature that is 300 to 550-C lower than the adiabatic flame temperature during combustion of the starting fuel.
.
It is also possible to burn the fuel that is introduced in a single combustion chamber 5, so that the combustion chamber 6 can be eliminated. When two combustion chambers are used, the measures aimed at reducing the flame temperatures can also be ~confined to the second combustion chamber 6, for the nitrogen oxides that are formed in the first combustion chamber will be decomposed to a very great extent by the effect of heat during the subsequent second combustion. This means that, in the first combustion, work can be done with higher exhaust gas temperatures and, because of this, under favourable conditions for the compressor drive gas turbine with respect to the highest possible turblne~efficiency, without this ultimately leading to higher N0 contents.~ The controlled temperature management is thus of particular~importance in the first instance for the last combust~ion~stage.
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Ihe mechanical energy that lS produced during expansion withln the turbine 1 is available for use on the output shaft 26 and can be used, for example, to drive a generator 6 to produce electrical current. The exhaust gas that has been cooled somewhat during expansion, but which is still hot, passes through the exhaust gas line 15 into the hot area of the indirectly heated reactor 7 for the endothermic reaction. `
Because of this endothermic reaction, which can take place as steam reformation, for example, a new fuel with an elevated absolute thermal value is generated from the starting fuel that has a specific absolute thermal value. For the case of steam reformation from natural gas that is introduced, for example, through the fuel feed line 18, a steam feed 19 leading into the reaction space of the reactor 7 is shown.
As a rule, it is useful to mix the steam with the fuel before this. The new fuel that is generated, which consists of a mixture of H2, C0, C02 non-converted CH4 and steam, is passed along the feed line 20 from the reaction chamber and into the combustion chambers 5 and 6, where it is burned, as described above. It is, of course, also possible to mix part of the starting fuel into the higher-value fuel in order to optimize the combustion processes (temperature, mass flow) within the combustion chambers 5 and 6. When this is done, it is most expedient to use a mixture with at least 50~, and preferably even more than 60% of the unconverted fuel. The smaller the amount of unconverted fuel that is contained, the more the efficiency will be réduced, according to tendency. The principle to the effect that--taken all in all--the fuel that is burned has a higher thermal-value than the starting fuel, is maintained in each case.
Some of~the higher value fuel can, of course, be decoupled from the process and used in other processes.
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During the steam reformation of natural gas (essentially CH4) that has been discussed above, the absolute thermal value of the fuel is increased by approximately 30~. In the case of hydrogenation of the starting fuel--toluol--the thermal value increase amounts to approximately 15~. In place of steam reformation, the endothermic reaction can be in the form of de-hydrogenation, for example. In the case of ethane as a starting fuel, this would result in a thermal value increase of approximately 10-20%, and in the case of methanol by approximately 20-30%. A further example for an endothermic reaction is the steam cracking of some hydrocarbon compounds (e.g., biogas, LPG, naphtha and kerosene).
This last-named possibility is interesting because it permits the alternating utilization of a number of different fuels to generate the mechanical energy, without the gas turbine having to be adjusted for a new fuel each time a different fuel is used.
The endothermic reaction is, as far as possible, to be carried out at temperatures below 780C or be~ter still, below 700-C.
The exhaust gas that is used for heating leaves the hot area of the reactor 7 through the exhaust gas line 16, when it i5 still at a relatively high temperature and, according to the present invention, is used, for example, for heating the exhaust gas heat exchanger 8, with which the ~ompressed combustion air is heated.
Finally, the cooled gas passes out of the exhaust gas heat exchanger through the exhaust gas line 17.
In the case of an endothermic reaction in which the use of steam is necessary, the process according to the present invention can be operated as a closed system insofar as this steam can be generated by using the heat that is available in the individual hot volume flows. In order to achieve an even higher overall efficiency for the process, at least one part of the reguired fresh steam can also be introduced from any ~team source, from ' .
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outside the reactor 7. In the lay-out diagra~, steam generators 21, 22, 23 have been drawn in with dashed lines at the locations in question as options, and these can be operated alternatively or simultaneously. The steam generator 21 is installed at the end of the system, in the exhaust gas line 17, and for this reason can only generate steam of a relatively low temperature.
A heat exchanger that is used to pre-heat the starting fuel (or a fuel/steam mixture) or to pre-heat the feed water for the steam generator could also be installed at this point.
A further possible place for the steam generator 22 is between the exhaust gas heat exchanger 8 and the reactor 7 in the exhaust gas line 16.
A preferred arrangement is to incorporate the steam generator 23 between the compressor drive gas turbine unit 2 and the second combustion chamber 6, for this arrangement has a positive effect in the sense of reducing the combustion temperature in the combustion chamber 6. If a plurality of steam generators 21 to ~23 i8 installed at the same time, these can be so arranged one behind the other that one (for example 21) generates steam at a relatively low temperature, and this steam i8 then superheated to a higher temperature in another (e.g. 22 and/or 23).
Fundamentally, the waste heat that occurs as a result of intèrmediate~cooling during compres~sion of the combustion air can be used in the cooler 4 to generate steam.
In the~ lay-out diagram shown in figure 1, the reactor 7 is installed in~the exhaust gas line 15, 16 of the gas turbine 1.
Nowever, it is also possible to provide for reactor heating with a~flow of~hot gas that is produced earlier in the process. For this~reason, the~reactor 7 could, in principle, be incorporated in the~lines 11, 12~, 13, or 14. Because of a temperature reduction~;in the~hot~gas flow, the turbine efficiency of the turbines ~I, or~2~r-apaot~valy, is reduced but, however~ NO~
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formation is also reduced at the same time. For this reason, the process parameters must be matched to each other in order to achieve the optimal effect.
In order to make it possible to start the system up from cold, when neither a hot gas flow nor sufficient converted fuel are available for use, as an alternative or simultaneously, provision can be made for the fact that the original fuel (e.g., natural gas) can be introduced in the combustion chamber 5 and the hot area of the reactor 7 and there burned, at least on a temporary basis.
The corresponding separate fuel feed lines (not shown herein) can be switched on briefly should the thermal output that is available in these aggregates be momentarily inadequate. Because of this, the overall operation of the installation is extremely simple to control. In addition, in order to provide better control and to optimize the overall system, provision can also be made for some of the energy produced in the gas turbine 2 for the compressor drive to be utilized as useable mechanical energy outside the system.
Figure 2 is a schematic representation of the second main variant of the process according to the present invention. In this drawing, components of the system that perform the same functions as in figure 1 bear the same reference numbers as in figure 1.
For this reason, the statements made with respect to figure 1 apply to figure 2 as well, so that only the differences between the two variants will be discussed in greater detail below.
The essential difference compared to figure 1 is the fact that the heat exchanger 8, which is configured as a recupterator for pre-heating the combustion air, has been eliminated, and in place of this there is a system to generate superheated steam that is used in a steam turbine 31 in order to produce mechanical energy.
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This steam generating system consists of a boiler 30 and a steam superheater 28.
The steam boiler 30 is heated with the residual heat from the exhaust gases that leave the gas turbine 1, once these gases have passed through the heating chamber of the reactor 7 and given up additional heat in so doing. The steam that is generated passes through the line 37 to the superheater 29 and from there through the line 38 to the steam inlet side of the steam turbtne 31. The expanded steam passes from the steam turbine 31 into a condenser 32. The condensate pump 33 delivers the condensed water into a de-gassing apparatus 34.
From there, the prepared boiler water is moved by the boiler feed pump 35 through a line into the boiler 30. Thus, the steam/water system is a largely closed circulatory system. Water losses that take place are made up by a water feed system (not shown herein).
These water losses occur, in particular, when, as is shown in fi~ure 2 by a dashed line 36, steam is decoupled from the high pressure section of the steam turbine 31 and introduced into the combustion chambers 5 and 6 to control the temperature and increase the mass flow. The line 19, which is also optional, can decouple steam from the circulating system in the same way and introduce this into the reaction chamber of the reactor 7.
However, this steam could be generated in another part of the system, as has already been discussed in connection with figure 1, or else supplied from outside the system. The water that is required to replenish the steam/water circulation system can be obtained by recovering condensate from the exhaust gas line 17.
For purposes of completeness, it should be mentioned that the feed line for introducing th~ compressed combustion air into the first combustion chamber 5 in figure 2 is numbered 27 and the hot gas line from the steam superheater 29 to the second combustion : .-, : . . : - , . ~ . :, , . ' - :, ' '. .. . .:, . :.- ~ .
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chamber 6 is numbered 28. In principle, the fact that the reactor 7 can be incorporated at another location in the hot gas lines also applies to the process variant that is shown in figure 2. A preferred solution for this is that the positions of the reactor 7 and of the steam superheater 2~ can be exchanged with each other.
A further advantageous configuration of the present in~ention (not shown in figures 1 and 2) relates to the utilization of the hot exhaust gas that is expanded in the gas turbine 1. In the normal course of events, this exhaust gas still contains a considerable 2 content because combustion is effected with an excess of 2- For this reason, this can be used, for example, as a cathode gas for the 2 supply of a fuel cell system in which electrical current is generated.
In fuel cell systems of this type, it is advantageous that cathode gas be introduced at a temperature that corresponds to the operating temperature of the fuel cells. Depending on the type of fuel cell system, the operating temperature lies at another level. Accordingly, the fuel cell system i9 incorporated at a suitable point in the exhaust gas line 15, 16, 17, i.e., the cooling of the expanded exhaust gas during heating of other media flows that are required in the process according tc the present invention (air pre-heating, steam generation, reformer heating) is carried out approximately up to the level that corresponds to the operating temperature that is desired in each instance, and then the flow of exhaust gas or a part thereof is introduced into the cathode chamber of the fuel cell system. The fuel cell system can be supplied with fuel by any H2 gas source (e.g., pipeline or gas accumulator). A partial flow of a gas enriched with H2, produced in the reactor 7, could also be introduced into the anode chamber of the fuel cell system.
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The effectiveness of the process according to the present invention is described in greater detail below, on the basis o~
an embodiment. A system diagram that corresponds to figure 1 has been used in order to do this. The heat exchanger 21 was used to generate steam and to pre-heat natural gas, whereas the heat exchanger 22 served to superheat the steam/natural gas mixture, before this mixture was passed to the steam reformer 7. The natural gas that was used as the starting fuel was at a line pressure of 20 bar and the water that was used was at a temperature of approximately 15C. The steam~carbon [sic] ratio (mol/mol) amounted to 2Ø For the remainder, the process parameters were selected in accordance with the following tabular compilation. In the interests of clarity, the same reference numbers are used here as in figure 1.
- Low pressure compressor (3a) inlet temperature 15 D C
Outlet temperature 1~0C
Outlet pressure 4.5 bar - High pressure compressor (3b) inlet temperature 25C
Outlet temperature 203~C
Outlet pressure 20 bar - Recuperator (8) Temperature rise in the combustion air 357C
Temperature drop of the exhaust gas 327C
- Combustion chamber (5) Temperature rise during combustion 6~0C
- Compressor drive turbine (2) Inlet temperature 1250C
Pressure ratio at the turbine 2.8 Outlet temperature 970-- Combustion chamber (6) Temperature rise during combustion 280OC
- Gas turbine (1) Inlet temperature 1250'C
Pressure ratio at the gas turbine 6.4 ' ~- ' ' .
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v ~ v Outlet temperature 780-C
- Generator (6) to generate electrical currPnt; power output 3200 KW~
- Steam reformer (7) Inlet temperature of superheated fuel/
steam mixture 550 C
Outlet temperature of the exhaust gas 647 C
Outlet temperature of the product gas 720-C
- Fuel/steam superheater (22) Inlet temperature fuel/steam mixture 249 C
Outlet temperature of the exhaust gas 610 n C
- Fuel pre-heater/steam generator (21) Outlet temperature of the exhaust gas 227-C
During the steam reformation of the natural gas that consists essentially of methane, some 12~ of the methane fraction was not converted and was burned in the combustion chambers 5 and 6 in its original form. With the exception of the energy for compression of the natural gas, which was available at sufficient line pressure, the total energy requirement for the process was covered by the process itself, so that there was no additional energy brought in from outside the system. The overall efficiency achieved thereby, i.e., the ratio of the generated electrical energy to the quantity of energy used from fuel on th~
basis of the lower thermal value amounted to 65%, and was thus was at an order of magnitude not previously achieved. When this was done, the exhaust gas that was discharged into the environment was characterized by a very low content of nitrogen oxides, without any additional nitrogen removel measures being required in order to achieve this.
The major advantage that is achieved by the present invention is the fact that it not only makes possible a drastic increase in efficiency during the generation of mechanical energy, using fuels that are based on hydrocarbon compounds, but also the fact .
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that this can be connected with a reduction in the content of injurious substances in the exhaust gas that i5 generated. In addition, there is the fact that, because of the special suitability of systems according to the present invention for decentralized generation of electricity, the losses that are incurred by moving electrical energy over long distances, using conventional technology of the sort found in large generating stations, and during the transformation of the current, are largely avoided.
... .. .
Claims (19)
1. A process for the continuous conversion of energy, chemically bound in a starting fuel based on C-H compounds, to useable mechanical energy, in which - combustion air is compressed;
- the energy needed for compression of the combustion air is obtained by using a compressor drive gas turbine unit through which at least the volumetric flow of the compressed combustion air is passed during partial expansion;
- the hot exhaust gas that results from combustion of fuel with the compressed combustion air is expanded in a gas turbine, with the help of which at least one part of the useable mechanical energy is generated; and - the residual heat of the exhaust gas that flows from the gas turbine is used to heat a media flow that is used in the process;
- the starting fuel is transformed into a converted fuel with a higher absolute thermal value by means of an endothermic reaction;
- the combustion is effected with or without the addition of starting fuel by using the converted fuel, when the individual combustible components of the converted fuel that are formed during the conversion are in each instance still contained either wholly or at least predominantly by quantity in the converted fuel that is to be burned; and - heating of the reaction chamber for the endothermic reaction is effected either by the compressed combustion air which has been previously heated to a higher temperature level by indirect heat exchange from the hot exhaust gas from the combustion, or by the total flow of the hot exhaust gas itself that results from combustion, prior to or after expansion of this, characterized in that the combustion is effected in two stages, the hot exhaust gas generated in the first stage and which has a larger excess of air is partially expanded in the compressor gas turbine unit and subsequently passed into the second combustion stage with additional fuel; and in that the hot exhaust gas that is generated in the second stage is expanded in the gas turbine, when it generates useable mechanical energy.
- the energy needed for compression of the combustion air is obtained by using a compressor drive gas turbine unit through which at least the volumetric flow of the compressed combustion air is passed during partial expansion;
- the hot exhaust gas that results from combustion of fuel with the compressed combustion air is expanded in a gas turbine, with the help of which at least one part of the useable mechanical energy is generated; and - the residual heat of the exhaust gas that flows from the gas turbine is used to heat a media flow that is used in the process;
- the starting fuel is transformed into a converted fuel with a higher absolute thermal value by means of an endothermic reaction;
- the combustion is effected with or without the addition of starting fuel by using the converted fuel, when the individual combustible components of the converted fuel that are formed during the conversion are in each instance still contained either wholly or at least predominantly by quantity in the converted fuel that is to be burned; and - heating of the reaction chamber for the endothermic reaction is effected either by the compressed combustion air which has been previously heated to a higher temperature level by indirect heat exchange from the hot exhaust gas from the combustion, or by the total flow of the hot exhaust gas itself that results from combustion, prior to or after expansion of this, characterized in that the combustion is effected in two stages, the hot exhaust gas generated in the first stage and which has a larger excess of air is partially expanded in the compressor gas turbine unit and subsequently passed into the second combustion stage with additional fuel; and in that the hot exhaust gas that is generated in the second stage is expanded in the gas turbine, when it generates useable mechanical energy.
2. A procedure as defined in claim 1, characterized in that after expansion through the gas turbine, the hot exhaust gas is used to heat the reaction chamber for the endothermic reaction.
3. A process as defined in claim 1 or claim 2, characterized in that the residual heat of the hot exhaust gas that is expanded in the gas turbine is used to heat the compressed combustion air.
4. A procedure as defined in one of the claims 1 and 3, characterized in that before it is partially expanded in the compressor drive gas turbine unit, the hot exhaust gas is used to heat the reaction chamber for the endothermic reaction.
5. A process as defined in claim 1 and claim 3, characterized in that after partial expansion in the compressor drive turbine unit but before being expanded in the gas turbine, the hot exhaust gas is used to heat the reaction chamber for the endothermic reaction.
6. A process as defined in one of the claims 1 to 5, characterized in that the composition of the media to reduce the formation of nitrogen oxides, which are introduced into the combustion stage or stages, is so adjusted that a flame temperature of lower than 1700°C (adiabatic flame temperature) results and the inlet temperature into the gas turbine is below 1250°C.
7. A procedure as defined in claim 6, characterized in that the outlet temperature is regulated by using an injection of water or steam into the combustion chamber.
8. A procedure as defined in one of the claims 1, 2 or 4 to 7, characterized in that the residual heat from the hot exhaust gas expanded in the gas turbine is used to generate steam that is superheated by using the hot exhaust gas flow that was previously at a higher temperature level, and to drive a steam turbine that also generates useable mechanical energy.
9. A process as defined in the claim 8, characterized in that super-heating of the generated steam is effected before the entry of the hot exhaust gas flow into the second combustion stage and the heating of the reaction chamber for the endothermic reaction is effected with the hot exhaust gas flow emerging from the gas turbine, before this is used to generate steam.
10. A process as defined in one of the claims 1 to 9, characterized in that the endothermic reaction is carried out in the form of steam reformation of C-H compounds, in particular in the form of a conversion of natural gas or biogas (CH4) into synthesis gas (Co and H2).
11. A process as defined in one of the claims 1 to 10, characterized in that the endothermic reaction is carried out at a temperature below 780°C, preferably below 700°C, and in particular below 650°C.
12. A procedure as defined in one of the claims 8 to 11, characterized in that part of the steam that is still not completely expanded is removed from the steam turbine and passed on for steam reformation.
13. An apparatus for carrying out the process as defined in claim 1 that, apart from a gas turbine (l) to generate useable mechanical energy, contains at least the following components:
- a compressor unit (3) that consists of at least a compressor (3a, 3b), which is used to compress the combustion air;
- a compressor drive gas turbine unit (2) that is used to drive the compressor unit (3), the gas inlet side of said unit (2) being connected through a line (10, 11, 12, 27) to the gas outlet side of the compressor unit (3);
- at least one compressor gas turbine unit (2) [portion of text missing--Tr.] arranged first combustion chamber (5), into which the line (11, 27, respectively) for the combustion air discharges;
- a hot gas feed line (12, 13, 14, 28) from the first combustion chamber (5) to the gas inlet side of the gas turbine (1);
- an exhaust gas line (15, 16) from the gas outlet side of the gas turbine (1) to a heat exchanger assembly (8, 30, respectively) for utilizing the residual heat from the exhaust gas;
- a reactor (7) for an endothermic chemical reaction, in which a converted fuel with a higher absolute thermal value can be generated from the starting fuel that is introduced through a fuel feed line (18), the reactor (7) with its heating system being connected to a line (11, 12, 13, 14, 15) that carries a hot medium; and - a fuel feed line (20) for the converted fuel that passes directly from the reactor (7) to the first combustion chamber (5), characterized in that between the compressor drive gas turbine unit (2) and the gas turbine (1) there is a second combustion chamber (6) incorporated in the hot gas feed line (13, 14) and the second combustion chamber (6) is similarly connected through a feed line (20) for the converted fuel to the reactor (7).
- a compressor unit (3) that consists of at least a compressor (3a, 3b), which is used to compress the combustion air;
- a compressor drive gas turbine unit (2) that is used to drive the compressor unit (3), the gas inlet side of said unit (2) being connected through a line (10, 11, 12, 27) to the gas outlet side of the compressor unit (3);
- at least one compressor gas turbine unit (2) [portion of text missing--Tr.] arranged first combustion chamber (5), into which the line (11, 27, respectively) for the combustion air discharges;
- a hot gas feed line (12, 13, 14, 28) from the first combustion chamber (5) to the gas inlet side of the gas turbine (1);
- an exhaust gas line (15, 16) from the gas outlet side of the gas turbine (1) to a heat exchanger assembly (8, 30, respectively) for utilizing the residual heat from the exhaust gas;
- a reactor (7) for an endothermic chemical reaction, in which a converted fuel with a higher absolute thermal value can be generated from the starting fuel that is introduced through a fuel feed line (18), the reactor (7) with its heating system being connected to a line (11, 12, 13, 14, 15) that carries a hot medium; and - a fuel feed line (20) for the converted fuel that passes directly from the reactor (7) to the first combustion chamber (5), characterized in that between the compressor drive gas turbine unit (2) and the gas turbine (1) there is a second combustion chamber (6) incorporated in the hot gas feed line (13, 14) and the second combustion chamber (6) is similarly connected through a feed line (20) for the converted fuel to the reactor (7).
14. An apparatus as defined in claim 13, characterized in that the reactor (7) is configured as a steam reforming apparatus.
15. An apparatus as defined in one of the claims 13 or 14, characterized in that between the compressor drive gas turbine unit (2) and the gas turbine (1) are arranged on a common shaft.
16. An apparatus as defined in one of the claims 13 to 15, characterized in that the reactor (7) together with its heating system, is connected to the exhaust gas line (15) that comes from the gas turbine (1); and in that the heat exchanger aggregate that is used to utilize the exhaust gas residual heat, which is incorporated in the exhaust gas line (16) that leads out of the reactor (7), is configured as an exhaust gas heat exchanger (8), the heated side of which is connected to the line (10, 11) for the compressed combustion air that runs from the compressor (3) to the first combustion chamber (5).
17. An apparatus as defined in one of the claims 13 to 15, characterized in that the heat exchanger aggregate that is used to utilize the exhaust gas residual heat in the exhaust gas line (15, 16) is configured as a steam boiler: in that a steam line (37) runs from the steam boiler (30) to a steam superheater (29) that, together with its heating system, is incorporated in lines (13, 15) that carry a hot exhaust gas;
and in that a steam turbine (31) is incorporated, the steam inlet side of which is connected through a steam line (38) to the steam super-heater (29).
and in that a steam turbine (31) is incorporated, the steam inlet side of which is connected through a steam line (38) to the steam super-heater (29).
18. An apparatus as defined in one of the claims 13 to 17, characterized in that a steam system is used, by means of which the steam that is generated in one or a plurality of steam generators (21, 22, 23) can be introduced into the reaction chamber of the steam reforming apparatus (7), particularly after being mixed with the starting fuel.
19. An apparatus as defined in one of the claims 13 to 18, characterized in that the combustion chambers (5, 6) incorporate a connector for injecting water or steam (feed line 35) in order to regulate the combustion temperature.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4003210A DE4003210A1 (en) | 1990-02-01 | 1990-02-01 | METHOD AND APPARATUS FOR GENERATING MECHANICAL ENERGY |
| DEP4003210.8 | 1990-02-01 |
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| Publication Number | Publication Date |
|---|---|
| CA2075290A1 true CA2075290A1 (en) | 1991-08-02 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002075290A Abandoned CA2075290A1 (en) | 1990-02-01 | 1991-01-18 | Process and device for generating mechanical energy |
Country Status (16)
| Country | Link |
|---|---|
| EP (1) | EP0518868B1 (en) |
| JP (1) | JPH05506290A (en) |
| KR (1) | KR920701627A (en) |
| CN (1) | CN1024212C (en) |
| AT (1) | ATE103037T1 (en) |
| CA (1) | CA2075290A1 (en) |
| CZ (1) | CZ280982B6 (en) |
| DE (2) | DE4003210A1 (en) |
| DK (1) | DK0518868T3 (en) |
| ES (1) | ES2051117T3 (en) |
| HU (1) | HUT67416A (en) |
| NO (1) | NO179298C (en) |
| PL (1) | PL165321B1 (en) |
| RU (1) | RU2085754C1 (en) |
| SK (1) | SK278798B6 (en) |
| WO (1) | WO1991011597A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2009118697A2 (en) * | 2008-03-26 | 2009-10-01 | L'air Liquide-Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Cogeneration of hydrogen and power |
Families Citing this family (27)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4032993C1 (en) * | 1990-10-15 | 1992-05-07 | Mannesmann Ag, 4000 Duesseldorf, De | |
| DK171830B1 (en) * | 1995-01-20 | 1997-06-23 | Topsoe Haldor As | Method for generating electrical energy |
| GB2299377A (en) * | 1995-03-29 | 1996-10-02 | Cyril Timmins | Gas turbine powere generation system |
| DE19627189A1 (en) * | 1996-07-05 | 1998-01-15 | Siemens Ag | Coal or oil, natural-gas compound electric power generating station |
| DE19719197A1 (en) * | 1997-05-09 | 1998-11-12 | Abb Research Ltd | Method and device for operating the combustion chamber of a gas turbine system with liquid fuel |
| GB0025150D0 (en) † | 2000-10-13 | 2000-11-29 | Air Prod & Chem | A process and apparatus for the production of synthesis gas |
| US6278169B1 (en) * | 1998-05-07 | 2001-08-21 | Analog Devices, Inc. | Image sensor shielding |
| DE19952885A1 (en) * | 1999-11-03 | 2001-05-10 | Alstom Power Schweiz Ag Baden | Process and operation of a power plant |
| FR2847620B1 (en) * | 2002-11-21 | 2006-06-16 | Jean Andre Bech | GAZOGENE TURBO-ENGINE AND WOOD GAS GENERATOR |
| FR2900934B1 (en) * | 2006-05-09 | 2012-09-21 | Inst Francais Du Petrole | PROCESS FOR COPRODUCTION OF ELECTRICITY AND HYDROGEN-RICH GAS BY VAPOREFORMING HYDROCARBON CUTTING WITH CALORIES BY IN SITU HYDROGEN COMBUSTION |
| EP2132489A1 (en) * | 2007-03-06 | 2009-12-16 | CeramTec AG | System concept with low energy requirement and improved energy yield |
| US8701413B2 (en) | 2008-12-08 | 2014-04-22 | Ener-Core Power, Inc. | Oxidizing fuel in multiple operating modes |
| AU2010205940A1 (en) * | 2009-01-15 | 2011-09-01 | Martin Hadlauer | Coupled gas/steam turbine |
| DE102009043499A1 (en) * | 2009-09-30 | 2011-03-31 | Uhde Gmbh | Method of operating an IGCC power plant process with integrated CO2 separation |
| RU2467187C2 (en) * | 2010-11-03 | 2012-11-20 | ООО "Центр КОРТЭС" | Method of operating gas turbine unit |
| JP2013092053A (en) * | 2011-10-24 | 2013-05-16 | Mitsubishi Heavy Ind Ltd | Liquefied gas processing system, control method thereof, liquefied gas carrying vessel including the same, and liquefied gas storage facility including the same |
| US9273606B2 (en) * | 2011-11-04 | 2016-03-01 | Ener-Core Power, Inc. | Controls for multi-combustor turbine |
| EP2938853B1 (en) * | 2012-12-28 | 2017-12-13 | Phoenix Biopower AB | Method and plant for transferring energy from biomass raw material to at least one energy user |
| CN105579686B (en) * | 2013-06-28 | 2018-02-23 | 埃克森美孚上游研究公司 | Utilize the system and method for axially stream expanding machine |
| US10036265B2 (en) | 2013-06-28 | 2018-07-31 | Mitsubishi Heavy Industries Compressor Corporation | Axial flow expander |
| DE102013212871A1 (en) * | 2013-07-02 | 2015-01-08 | Siemens Aktiengesellschaft | Thermal engineering of power plant, steam reformer and thermal water treatment |
| RU2561755C2 (en) * | 2013-11-07 | 2015-09-10 | Открытое акционерное общество "Газпром" | Operating method and system of gas-turbine plant |
| RU2599407C1 (en) * | 2015-06-09 | 2016-10-10 | Федеральное государственное унитарное предприятие "Центральный институт авиационного моторостроения имени П.И. Баранова" | Method of continuous operation gas turbine plant action |
| DE102015219398A1 (en) * | 2015-10-07 | 2017-04-13 | Siemens Aktiengesellschaft | Method for operating a gas-and-steam combined cycle power plant and gas and steam combined cycle power plant |
| CN107917433A (en) * | 2017-11-22 | 2018-04-17 | 苏州克兰茨环境科技有限公司 | A kind of Microturbine organic waste gas treatment device |
| CN109268092A (en) * | 2018-08-02 | 2019-01-25 | 上海柯来浦能源科技有限公司 | A kind of hydrogen mixed working fluid dynamical system using air-energy |
| WO2022156523A1 (en) * | 2021-01-25 | 2022-07-28 | 李华玉 | Dual-fuel gas-steam combined cycle power device |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1219732B (en) * | 1958-07-12 | 1966-06-23 | Maschf Augsburg Nuernberg Ag | Method for operating an internal combustion engine with continuous combustion, for example a gas turbine |
| NL302138A (en) * | 1963-02-19 | |||
| DE1228856B (en) * | 1965-06-09 | 1966-11-17 | M A N Turbo G M B H | Internal combustion engine with continuous combustion, in particular a gas turbine system |
| CH626976A5 (en) * | 1978-01-03 | 1981-12-15 | Rawyler Ernst Ehrat | |
| US4478039A (en) * | 1980-12-29 | 1984-10-23 | United Technologies Corporation | Utilization of coal in a combined cycle powerplant |
| JPS58162730A (en) * | 1982-03-22 | 1983-09-27 | Setsuo Yamamoto | Gas turbine apparatus |
| DE3331153A1 (en) * | 1983-08-30 | 1985-03-14 | Brown, Boveri & Cie Ag, 6800 Mannheim | Gas turbine system for open process |
| JPS62214235A (en) * | 1986-03-17 | 1987-09-21 | Mitsui Eng & Shipbuild Co Ltd | Gas turbine power generation system using methanol as fuel |
| GB8629031D0 (en) * | 1986-12-04 | 1987-01-14 | Shell Int Research | Producing hydrogen |
| NL8702834A (en) * | 1987-11-26 | 1989-06-16 | Turbo Consult Bv | PLANT FOR GENERATING MECHANICAL ENERGY AND METHOD FOR OPERATING SUCH PLANT. |
| EP0351094B1 (en) * | 1988-04-05 | 1994-03-23 | Imperial Chemical Industries Plc | Gas turbines |
-
1990
- 1990-02-01 DE DE4003210A patent/DE4003210A1/en not_active Withdrawn
-
1991
- 1991-01-18 HU HU9202499A patent/HUT67416A/en unknown
- 1991-01-18 RU SU915052977A patent/RU2085754C1/en active
- 1991-01-18 DK DK91902259.0T patent/DK0518868T3/en active
- 1991-01-18 DE DE91902259T patent/DE59101211D1/en not_active Expired - Fee Related
- 1991-01-18 WO PCT/DE1991/000064 patent/WO1991011597A1/en active IP Right Grant
- 1991-01-18 JP JP91502379A patent/JPH05506290A/en active Pending
- 1991-01-18 EP EP91902259A patent/EP0518868B1/en not_active Expired - Lifetime
- 1991-01-18 ES ES91902259T patent/ES2051117T3/en not_active Expired - Lifetime
- 1991-01-18 KR KR1019910701034A patent/KR920701627A/en not_active Application Discontinuation
- 1991-01-18 CA CA002075290A patent/CA2075290A1/en not_active Abandoned
- 1991-01-18 AT AT91902259T patent/ATE103037T1/en not_active IP Right Cessation
- 1991-01-30 PL PL91288895A patent/PL165321B1/en unknown
- 1991-02-01 SK SK243-91A patent/SK278798B6/en unknown
- 1991-02-01 CZ CS91243A patent/CZ280982B6/en unknown
- 1991-02-01 CN CN91101391A patent/CN1024212C/en not_active Expired - Fee Related
-
1992
- 1992-07-30 NO NO923011A patent/NO179298C/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009118697A2 (en) * | 2008-03-26 | 2009-10-01 | L'air Liquide-Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Cogeneration of hydrogen and power |
| WO2009118697A3 (en) * | 2008-03-26 | 2009-11-26 | L'air Liquide-Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Cogeneration of hydrogen and power |
Also Published As
| Publication number | Publication date |
|---|---|
| DE59101211D1 (en) | 1994-04-21 |
| NO179298B (en) | 1996-06-03 |
| JPH05506290A (en) | 1993-09-16 |
| RU2085754C1 (en) | 1997-07-27 |
| PL165321B1 (en) | 1994-12-30 |
| SK278798B6 (en) | 1998-03-04 |
| ES2051117T3 (en) | 1994-06-01 |
| NO923011D0 (en) | 1992-07-30 |
| PL288895A1 (en) | 1991-10-21 |
| KR920701627A (en) | 1992-08-12 |
| EP0518868A1 (en) | 1992-12-23 |
| ATE103037T1 (en) | 1994-04-15 |
| NO923011L (en) | 1992-09-23 |
| EP0518868B1 (en) | 1994-03-16 |
| CS9100243A2 (en) | 1991-08-13 |
| DK0518868T3 (en) | 1994-05-09 |
| HUT67416A (en) | 1995-04-28 |
| CN1024212C (en) | 1994-04-13 |
| WO1991011597A1 (en) | 1991-08-08 |
| CZ280982B6 (en) | 1996-05-15 |
| NO179298C (en) | 1996-09-11 |
| DE4003210A1 (en) | 1991-08-14 |
| CN1057315A (en) | 1991-12-25 |
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| EEER | Examination request | ||
| FZDE | Discontinued |