Emission-free devices and method for performing mechanical work and for generating electrical and thermal energy
11397004 · 2022-07-26
Assignee
Inventors
Cpc classification
C10J3/66
CHEMISTRY; METALLURGY
F23J15/006
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F23J15/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
C10J3/66
CHEMISTRY; METALLURGY
F02M25/03
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
The device for performing mechanical work and/or producing electrical or thermal energy, the energy necessary for operation is obtained from the oxidation of carbonaceous fuels into carbon dioxide and water. The device comprises means for compression and/or condensation of the exhaust gas, and storage means for receiving the compressed and/or condensed exhaust gas.
Claims
1. A fuelling installation for fuelling a mobile machine with gaseous or liquid fuels, wherein the mobile machine comprises a device for performing mechanical work and/or for producing electrical energy that obtains the energy necessary for operation from the oxidation of carbonaceous fuels into an exhaust gas consisting essentially of carbon dioxide and water, and wherein the mobile machine comprises a device for compressing and/or condensing the exhaust gas and a storage means in the form of a carbon dioxide pressure tank for receiving the compressed and/or condensed exhaust gas; and the fuelling installation comprises a gas storage means in the form of a carbon dioxide pressure tank for receiving carbon dioxide discharged from the carbon dioxide pressure tank of the mobile machine, the gas storage means of the fuelling installation being connected to a return network that transports carbon dioxide to another storage means; means for fuelling the mobile machine with oxygen or oxygen-enriched air; and a fuel tank that is connected to a supply network that supplies fuel to the fuel tank.
2. A fuelling installation for fuelling a mobile machine with gaseous or liquid fuels, wherein the mobile machine comprises a device for performing mechanical work and/or for producing electrical energy that obtains the energy necessary for operation from the oxidation of carbonaceous fuels into an exhaust gas consisting essentially of carbon dioxide and water, and wherein the mobile machine comprises a compressor and/or a condenser for receiving the exhaust gas and a storage in the form of a carbon dioxide pressure tank for receiving the compressed and/or condensed exhaust gas; and the fueling installation comprises a connection to a return network, the return network being a) configured for the removal of compressed gases, including said carbon dioxide, from the carbon dioxide pressure tank of the mobile machine and b) being connected to a production installation that produces fuel from said carbon dioxide; a supply network for fuelling the mobile machine with oxygen or oxygen-enriched air; and a connection to a fuel tank that is connected to a supply network that supplies fuel from the production installation that produces fuel from said carbon dioxide to the fuel tank.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) In order to facilitate a fuller understanding of the present invention, reference is now made to the appended drawings. These references should not be construed as limiting the present invention, but are intended to be exemplary only.
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DETAILED DESCRIPTION OF THE EMBODIMENTS
(10) The examples specified hereinafter are given for an improved illustration of the present invention, but are not to restrict the invention to the features which are disclosed in them.
(11) As already explained, with the method and the device 1 according to the invention for performing mechanical work and/or for the production of electrical or thermal energy, the energy required for the operation is obtained from the oxidation of carbonaceous fuel into exhaust gas. The exhaust gas resulting from the oxidation reaction is compressed and/or condensed and is captured in a storage means. The utilisation of chemical energy is effected thermo-chemically or electro-chemically. Such methods and devices 1 according to the invention have a closed cycle, which means that no emissions into the atmosphere arise.
(12) The residual substances which occur with the performance of mechanical work or production of electrical or thermal energy, such as in particular carbon dioxide, are aftertreated, compressed, and stored in a space-saving manner, for example in a pressure tank. The stored gas mixture essentially contains only carbon dioxide, and as the case may be water. The carbon dioxide is regularly relocated into a suitable, larger storage device for further utilisation. Advantageously, this leading back of the carbon dioxide is effected at the same time as the fuelling of a vehicle.
(13) In one advantageous variant of a method and a device according to the invention, the stored carbon dioxide is partly or completely recycled.
(14) In the international application No. PCT/EP2010/067847 of the applicant, a method and an installation for the thermo-chemical treatment and utilization of carbonaceous materials is disclosed.
(15) In an essentially closed circuit, in the installation 6 carbonaceous starting material 27 is converted into hydrocarbons 20 and hydrocarbon derivatives. For that purpose in a first stage 61a and a second stage 61b the carbonaceous starting material 27 is converted into synthesis gas mixture 65. In a first stage 61a the carbonaceous substances are provided and pyrolysed and pyrolytic coke and pyrolytic gas result. In a second stage 61b, the pyrolytic coke from the first stage is gasified and synthesis gas mixture 65 results, and slag and other residual substances remain. In a third stage 62, hydrocarbons and other valuable materials 20 are produced from the synthesis gas mixture 65, which can be used for other purposes, for example as liquid and/or gaseous fuels 20. The recycle gas mixture 66 that remains after the synthesis stage 62 essentially comprises carbon dioxide, and is led back into the first stage as a gasification agent. The three stages are pressure-resistantly closed, and form an essentially closed cycle. With such an utilisation installation 6, solid, liquid and gaseous substances can be efficiently converted into gaseous or liquid fuels 20. In addition the installation 6 produces thermal energy in the form of process steam (not shown). The carbonaceous fuels produced in the synthesis stage 62 are preferably stored intermediately 81, in tanks of pressure storage means.
(16) A device 1 according to the invention advantageously uses as a fuel gaseous or liquid hydrocarbons and hydrocarbon derivatives 20 from the installation 6. The oxidation reaction producing thermal or electrical energy is effected with oxygen-enriched air, advantageously with an oxygen content >95%, or pure oxygen 22 instead of air. The oxygen is advantageously carried along in a pressure tank. A device 1 according to the invention can for example be an internal combustion engine, in which the heat resulting from the oxidation reaction is converted in a thermal engine into mechanical work, or a fuel cell in combination with an electric motor, in which the oxidation reaction is directly utilised for the production of electricity.
(17) The use of pure oxygen 22 instead of air on the one hand avoids the formation of nitrogen oxides, due to the absence of air nitrogen in a thermo-chemical reaction at high temperatures. Above all, however, in the occurring reaction products 21 remain essentially only carbon dioxide 24 and water vapour 23. Depending on the stochiometrics of the reaction, the occurring gases can also contain certain fractions of carbon monoxide and unreacted fuel. These can be subsequently aftertreated analogously to the carbon dioxide.
(18) The reaction products 21 of the energy producing reaction are essentially gaseous. The respective gas mixture is then compressed in order to reduce the volume. The gas mixture 21 is cooled with the help of a heat exchanger before and/or after the compressing, by which means it further reduces its volume. Water is condensed out, by which means the volume of the gas mixture is reduced once more, and only carbon dioxide 24 remains in the gas mixture, and as the case may be, with fractions of carbon monoxide and unreacted fuel. The condensed water 23 is separated. The carbon dioxide 24 can be intermediately stored in a suitable reservoir, for example in a pressure tank.
(19) At regular intervals the carbon dioxide 24 is again fed to the first step 61a of the installation 6, so that a closed material cycle for the carbon dioxide results. An intermediary storage means 82 for the exhaust gas containing carbon dioxide can be provided. With the method mentioned above it is thus possible to produce liquid or gaseous hydrocarbons and hydrocarbon derivatives from carbonaceous substances and carbon dioxide, and to subsequently convert the resulting fuel mixture in a device 1 according to the invention into mechanical work and/or electrical or thermal energy. The captured and stored carbon dioxide is led back and is partly or completely converted into fuel 20 again in the installation 6. In this manner, the effective carbon dioxide emission of a device according to the invention can be greatly reduced or even avoided.
(20) Alternatively or additionally to the recycling, a part of the stored carbon dioxide can be deposited in a way and manner such that it is permanently prevented from getting into the atmosphere. Corresponding technologies for the permanent, long-term storage of carbon dioxide are being developed worldwide at present. For example, the final storage of carbon dioxide by way of pumping into empty oil fields and natural gas fields is being tested.
(21) A further, generalised variant of a device 1 according to the invention for carrying out a method according to the invention is schematically represented in
(22) If a device 1 according to the invention is designed as an internal combustion engine, then in an advantageous variant of such a device or method according to the invention, water 23 can be used as an additional expansion means. For this purpose, after igniting the combustion process, for example after the self-ignition of the compressed fuel-air mixture in a diesel motor, a certain quantity of water is injected into the cylinder. This water, which is preferably atomised in a fine manner, is subsequently evaporated by way of the thermal energy of the exothermic oxidation reaction. The resulting gas pressure increase or gas volume increase on account of the water vapour thus contributes to the production of kinetic energy, wherein simultaneously the temperature of the complete mixture of combustion exhaust gases and water vapour is reduced. This, however, is of no problem or is even desirable, since significantly higher reaction temperatures arise on account of the greater energy density of a reaction with pure oxygen, which improves the thermodynamic efficiency, but can also strain parts of a device 1 according to the invention to a greater extent.
(23) Alternatively, the water can be introduced as steam. Furthermore a certain fraction of liquid water can also be supplied mixed with the liquid fuel. At high temperatures, superheated water vapour acts as an additional oxidant in addition to oxygen.
(24) The manner of functioning of a method according to the invention is hereinafter described and explained in more detail by way of the example of a device 1 according to the invention, in the form of a piston engine. Analogously, devices according to the invention designed as internal combustion engines can also be designed as turbines or Wankel engines, etc. The hot exhaust gases are used for the performance of mechanical work, in accordance with the functioning principle of the respective type of an internal combustion engine, and are thereby partly expanded. Subsequently the gas mixture leaves the combustion chamber. With an internal combustion engine according to the invention designed as a four-stroke piston engine, for example, the exhaust gas mixture is ejected from the cylinder with the third stoke and subsequently compressed, cooled and intermediately stored.
(25) One possible embodiment of a device 1 according to the invention for carrying out a method according to the invention, designed as an internal combustion engine, is schematically represented in
(26) The hot exhaust gases 21, which consist essentially only of carbon dioxide and water vapour, are subsequently cooled in a heat exchanger 13 arranged downstream. By way of this, the volume of these exhaust gases 21 is reduced. A part of the water 23 is condensed out by way of the cooling, and is separated. The residual gas, which consists now only of carbon dioxide 24 and, as the case may be, the residual fractions of carbon monoxide and unreacted fuels, is compressed in a compressor 14 arranged in series and is pumped into a storage means 15, in the simplest case into a pressure container. The condensation stage 13 before the compressing 14 reduces the undesired formation of condensation water droplets in the compressor 14.
(27) The depicted combustion engine 1 according to the invention has no emissions. Since the device is not operated with air or similar mixtures, also no air-specific pollutants can arise, such as for example nitrogen oxides. The water that arises with the combustion is not problematic and can be separated. The carbon dioxide and other residual gases are captured in the storage means 15 and stored for further use. Uncombusted fractions of the fuel are either condensed out with the water and separated, or are compressed together with the carbon dioxide.
(28) Apart from the basic elements C, H, O, in the fuels for a device according to the invention sulphur and phosphorus can also be present, depending on the degree of quality. The sulphur for example can react during combustion into sulphur dioxide and sulphur trioxide, which in turn reacts with the water into sulphurous acid and sulphuric acid. These corrosive pollutants, together with the water can be condensed out, separated away and disposed off. The same applies to phosphorus-containing pollutants and, as the case may be, arising fine dust particles.
(29) A further possible embodiment of a device 1 according to the invention for carrying out a method according to the invention, designed as an internal combustion engine, is schematically represented in
(30) This is effected preferably in a manner such that during or after the combustion reaction, a certain quantity of liquid or vaporous water 23 is injected into the combustion chamber and is finely distributed. This water is heated by way of the combustion heat, by which means the complete gas volume increases in the combustion chamber 11, and thus also the gas pressure or gas volume which is available for the performance of mechanical work. Accordingly then, given a constant power, the quantity of fuel can be reduced.
(31) Alternatively or additionally, water can also be brought into the exhaust gas flow 21 when it has left the combustion chamber 11. Such a variant has the advantage that the combustion reaction in the combustion chamber can run in an efficient manner at temperatures as to high as possible, and simultaneously the resulting temperature of the exhaust gas flow is so low that the downstream devices 13, 14 are not strained too much.
(32) The quantity of water and the point in time of the injection are thus matched to the feed of fuel 21 and oxygen 22, such that the combustion reaction can take place in an efficient manner. Advantageously, the resulting temperature during the oxidation reaction is essentially such that an as high as possible thermodynamic efficiency of the thermal engine is achieved. The larger the quantity of applied water, the lower is further the relative fraction of carbon dioxide in the reaction gases, which reduces the gas quantity that remains after condensing out the water, and which is to be compressed.
(33) In the device 1 depicted in
(34) The energy that is necessary for the operation of the compressor of a device 1 according to the invention is advantageously produced by the device according to the invention itself. As a result of this, the achievable efficiency of the device according to the invention is reduced. However, simultaneously the emission-free nature of the device and method according to the invention is achieved. Moreover, given the same engine dimensions, the achievable power is larger, which again compensates the power loss.
(35) The compressor can for example be operated via a suitable gear directly with a crank shaft of a piston internal combustion engine. If the device 1 according to the invention is designed as a turbine, then the compressor can be seated directly on the same shaft. The exhaust gases can then be condensed directly subsequently to the expansion procedure, and the remaining residual flow can be compressed.
(36) In another variant of a device according to the invention, designed as a piston engine, the exhaust gases get already precompressed within the combustion chamber 12 with the third stroke, and then are discharged through the exhaust device 12. The compressor 14 arranged downstream can also be omitted, as the case may be.
(37) Such an embodiment is also possible as a two-stroke variant, since the new charging of the combustion chamber with a reaction mixture (fuel 20, oxygen 22, water 23) in a device according to the invention can be effected very quickly. In a second upwards stroke, the exhaust gases are precompressed and are let out of the combustion chamber towards the end of the stroke. The gaseous oxygen can be blown into the combustion chamber under high pressure at the end of the upwards stroke, since one requires comparatively little oxygen for a complete combustion reaction, and water is present as an additional expansion means. The liquid fuel 20 and the water 23 as an expansion means can in any case be injected into the combustion chamber in a very rapid manner and under high pressure.
(38) The energy consumption for the compressor can be optimised by way of a suitable combination with one or more heat exchangers or cooling elements, in which the gas volume can be reduced by way of the release of the thermal energy of the reaction gases to an internal or external heat sink.
(39) It is likewise possible to realise a device 1 according to the invention as a thermal engine with external combustion, for example as a steam engine or steam turbine or as a Sterling motor.
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(41) In a combustion chamber 710 connected ahead of the turbine, fuel 20 is burned with oxygen 22 in a burner 714, producing a very hot exhaust gas. Water 23′ is brought into the combustion chamber 710, preferably as overheated liquid water with a temperature of, for example, above 250° C., and a pressure of 50 bar. The resulting water vapour mixes with the combustion exhaust gases, resulting in a hot (e.g. 600° C.) exhaust gas 21′ with a large fraction of overheated water vapour. Said exhaust gas leaves the combustion chamber 710 and is converted into mechanical work 78, in a following turbine device 719, which again drives an electric generator assembly 74. Depending on the design of the device, the gas mixture in the combustion chamber behaves isochorically, such that the gas pressure increases, or isobarically, such that the gas volume increases accordingly, or both the volume and the pressure increase. The subsequent turbine device 719 has to be designed correspondingly. Suitable turbines 719 are known from the prior art, and generally comprise several stages. In an alternative variant, partially expanded process steam 77 can be removed after a high pressure stage of the turbine device 719, and used otherwise.
(42) The expanded exhaust gas 21″ is led into a condenser/economizer 73, where the water is condensed out and separated. The remaining recycle gas 24, which essentially comprises carbon dioxide, is compressed in a compressor 72. Subsequently it is stored intermediately in a gas storage means 15, or is directly conveyed into a first stage of a utilisation installation 6. The compressor 72 is advantageously driven via the turbine 719.
(43) Instead into the combustion chamber 710, the water 23′ can also be mixed into the exhaust gas stream 21′ subsequent to the combustion chamber 710, for example with a Venturi nozzle.
(44) In the drive device 71, the amount of water 23′ and the amount of fuel mixture 20, 22 and the other parameters that can be chosen are advantageously adjusted to each other such that the subsequent turbine achieves an energy efficiency as high as possible. At the same time the amount of water in the exhaust gas mixture should be as high as possible. On the one hand, this way an as high as possible pressure drop of the gas mixture over the condenser 73 is achieved. This increases the total pressure difference over the turbine 719, and thus its efficiency. On the other hand, less recycle gas 24 remains that has to be compressed 72 and stored 15.
(45) A further advantage of bringing water vapour into the combustion chamber is the cooling effect of the vapour. The exothermic oxidation of the very energy rich fuel mixture can lead to very high temperatures, of up to 1000° C. or even 2000° C. Such temperatures would strain very strongly the structures of the combustion chamber 719 and the following turbine device 719. The comparably cold water vapour is advantageously brought into the chamber in such a way that it shields the walls of the combustion chamber 710 from the very hot flame 715. The vapour eventually cools the complete gas mixture down to 600° C. to 800° C., which decreases the thermal strain of the turbine blades, and increases their life span.
(46) In addition to the already mentioned aspects, the shown drive device 1 differs from a conventional gas turbine in that no compressor is connected ahead of the combustion chamber. This allows a simpler design of the combustion chamber 710 than in a gas turbine. Since the fuels 20 are burned with pure oxygen 22, the achievable energy density is higher than with air, with its reduced oxygen content. To increase the amount of oxygen per time unit that can be brought into the combustion chamber 710, the oxygen ban be pressurized. The turbine device 719 can be designed like a steam turbine, since the temperature and pressure ranges of the exhaust gases 21′ are essentially the same
(47) A vehicle 3 driven by a device 1 according to the invention is schematically depicted in
(48) The vehicle 3 comprises a tank 31 for the liquid or gaseous fuel 20 as well as a pressure tank 32 for the oxygen 22. The gas storage means 15 for the carbon dioxide is advantageously designed as a pressure tank 15. A device 1 according to the invention is particularly suitable for less weight-sensitive vehicles, such as for example land and water vehicles, in particular vehicles for urban transport or ships and larger boats. It is also possible to produce oxygen on location, depending on the size of the vehicle, by which means the pressure tank 32 merely serves as an intermediate storage means and may be designed accordingly smaller.
(49) Not shown in
(50) Likewise represented in
(51) In another embodiment of a device according to the invention, the thermal energy arising in the oxidation reaction is not converted into mechanical work, but is used to heat a fluid heat transport medium. This means that the device serves to produce thermal energy. For the heat transport medium, serving to transport the generated thermal energy, for example water, oil or steam can be used.
(52) In a possible variant of such a device according to the invention, the energy producing oxidation reaction takes place in a suitably designed combustion chamber, which is equipped with means to heat the transport medium, for example a heat exchanger. These means also serves for cooling down the arising exhaust gas stream.
(53) The heated heat transport medium subsequently can be used in industrial installations, or for heating buildings. For example, a district heating station or a block-type heating station, respectively, can be equipped with such a device according to the invention.
(54) The fuelling installation 41 forms a closed cycle with the fuel production installation 6, as is disclosed in the international application No. PCT/EP2010/067847 of the applicant. The installation 6 produces liquid or gaseous hydrocarbon fuels 20 from carbonaceous starting materials 27. These fuels are transported to the fuelling installation 41 with suitable means. The carbon dioxide 24 in turn, as the case may be with fractions of carbon monoxide and unreacted fuel, which has been discharged from the vehicle 3 into the fuelling installation 41, is transported via suitable means to the installation 6 where it is fed into the closed cycle of the installation 6.
(55) A fuelling installation 41 is particularly suitable for example for public bus transport enterprises. Generally, such buses are refuelled exclusively in the fuelling installations of the enterprise. Thus a large number of vehicles 3 can be reached with a comparatively low number of fuelling installations 41 to be retrofitted. This leads to lower investment costs in a corresponding total installation.
(56) In regions that are spatially clearly defined, for example of a town, the recycling of the carbon dioxide and/or the supply with fuel can also be effected via a suitable supply network 5. With a method according to the invention, for the supply of one or more consumers with gaseous and/or liquid fuels for this method, the consumers are supplied by a first supply network with gaseous and/or liquid fuels from one or more production installations and/or form one or more first storage means. At least a part of the exhaust gases, in particular carbon dioxide, which occur with the drive method, are led with a second return network from the consumers to one or more production installations and/or to one or more second storage means.
(57)
(58) Additionally, a second return network 52 is present, into which the fuelling installations 41 and the electricity power station 43 feed the accruing carbon dioxide 24. The carbon dioxide in turn is led back to the production installation 6. A second intermediate storage means 82 serves for increasing the capacity of the second network. Additionally, a final storage 44 for carbon dioxide is provided in the shown variant. Carbon dioxide can be tapped from the second network and be pumped under pressure into an exhausted oil field, where it then remains permanently.
(59) If a device according to the invention is connected to such a supply system 5 according to the invention, a fuel tank 31 and/or gas storage means 15 for the carbon dioxide can be completely omitted, since the fixed conduit system assumes this function. This is the case for example with the electricity production installation 43 in
LIST OF REFERENCE NUMERALS
(60) 1 device 11 combustion chamber 111 cylinder 112 piston 12 exhaust device 13 heat exchanger 14 device for compressing, compressor 15 gas storage means 16 feed device for oxygen 17 feed device for water 18 feed device for fuel 20 fuel 21, 21′, 21″ reaction products, product gases, combustion gases, exhaust gases 22 oxygen 23, 23′ water 24 carbon dioxide 25 hydrogen 27 carbonaceous starting materials 3 vehicle, mobile or stationary machine 31 fuel tank 32 oxygen tank 41 fuelling installation 43 installation for electricity production 44 final storage for carbon dioxide 5 supply system 51 supply network fuel 52 return network carbon dioxide 6 installation for the thermo-chemical utilisation of carbonaceous substances 61a first stage for producing synthesis gas mixture 61b second stage for producing synthesis gas mixture 62 third stage for producing hydrocarbon derivatives and other valuable materials 63 pyrolytic coke 64 pyrolytic gas 65 synthesis gas 66 recycle gas with carbon dioxide 71 device 710 combustion device 711 cylinder 712 piston 713 exhaust device 714 burner 715 flame 716 feed device for oxygen 717 feed device for water 718 feed device for fuel 719 turbine 72 compressor 73 condenser/economizer 74 generator device 75 external cooling circuit 76 electric energy 77 process steam 78 mechanical energy 81 first storage means, storage means for fuels 82 second storage means, storage means for exhaust gases