Patent Application
20160186078
The present invention relates to a C-converter (carbon converter) an apparatus incorporating a C-converter and methods for using the same.
DE 10 2012 008 933 discloses a method and an apparatus for producing carbon monoxide, wherein carbon monoxide is produced from carbon dioxide in the presence of carbon at a temperature of more than 850° C. Furthermore DE 10 2012 010 542 discloses a method and an apparatus for producing a synthesis gas. In both of the above mentioned prior art methods, a stream of hot particles containing carbon is directed into a carbon converter. In these prior art methods, conversion in the carbon converter may be incomplete. Furthermore, heat losses may occur, which affect the cost effectiveness of these known methods. In the known methods and apparatuses, particles may deposit in the converter which may cause interruptions of the operation.
U.S. Pat. No. 6,077,490 A discloses an apparatus for filtering hot synthesis gas which comprises a filter having two filter chambers, which are used alternately as filter and cleaned. During operation, hot synthesis gas containing unreacted carbon soot is directed into one of the filter chambers. As soon as too much carbon soot has accumulated, the cleaning step is carried out by admitting air, i.e. N2 and O2, in a reverse flow. The accumulated carbon is burnt off. Thus, inert gas purge which leads to accumulations of soot may be avoided. U.S. Pat. No. 5,809,911 A discloses a waste treatment system which burns or melts mixed waste materials. Stable effluent gasses are treated in a gaseous effluent processing subsystem, which includes a high temperature filter. The high temperature filter comprises two filter elements, which filter particles entrained in the effluent gasses and are operated in parallel. The filter elements may be backflushed in parallel with air (i.e. N2 and O2), N2 or steam. The backflushed particles will settle on the waste combustion bed where the particles mix with the slag.
Accordingly, the object of the present invention is to provide a carbon converter and a method of operating the carton converter which may overcome at least one of the above problems, in particular enables long and uninterrupted periods of operation, and wherein the materials directed into the converter may be completely converted.
This problem is solved by a C-converter comprising at least one aerosol converter inlet for an aerosol comprising a first gas (hydrogen) and particles containing carbon; furthermore at least one converter gas inlet for a second gas (H2O or exhaust gas containing CO2); at least two converter outlets; and at least two converter chambers each comprising at least one filter adapted to filter particles containing carbon from the aerosol. The C-converter further comprises at least one diverting device adapted to alternately connect a fraction of the at least two converter chambers with a) at least one aerosol converter inlet or b) with least one converter gas inlet; and at least one discharging device adapted to alternately connect a fraction of the at least two converter chambers with at least one of the converter outlets or to disconnect the same. The C-converter is able to convert aerosols containing carbon particles without interruption, and a high degree of conversion of the materials supplied into the converter maybe achieved. The aerosol consists of carbon particles and hydrogen. Thus, no residual materials remain, and the supplied materials are completely converted. The at least one aerosol converter inlet is connected to at least one hydrocarbon converter adapted to operate with plasma and adapted to decompose fluids containing hydrocarbons into an aerosol comprising particles containing carbon and hydrogen.
In one embodiment of the C-converter, the second gas is an exhaust gas containing CO2, such as from an industrial plant, particularly from a power plant or a blast furnace. Thus, CO2, which is detrimental to the climate, may be converted inside the C-converter into carbon monoxide which is a chemical base material. Alternatively, the second gas is H2O steam (water steam). Thus the aerosol may be converted into a CO/H2 gas mixture inside the C-converter, wherein the CO/H2 gas mixture is referred to as synthesis gas and serves as a chemical base material.
Preferably, the filter is a heat resistant mesh filter or a ceramic filter, since high temperatures prevail in the C-converter so as to achieve fast and complete conversion of the particles containing carbon.
Preferably, the converter chambers of the C-converter comprise a porous ceramic base as a filter and a ceramic shell. Thus a simple construction of the converter chambers may be achieved and a long service life may be ensured.
Preferably, the converter chambers are arranged side by side, to obtain a heat transfer from one converter chamber to an adjacent converter chamber. During operation, hot aerosol is supplied alternately into the converter chambers and, as soon as the converter chambers are filled to a pre-determined particle filling degree with particles containing carbon, the converter chambers are regenerated by supplying the second gas thereto at high temperatures. Heat transfer between adjacent converter chambers prevents that a high loss of heat occurring during regeneration periods. An additional heater may be avoided or, at least, may be implemented smaller.
Preferably, the converter chambers are tubular and extend parallel side by side as a tube bundle. The tubular shape may have a cylindrical, triangular, square or hexagonal cross section. Thus, the converter chambers may be adapted to the surrounding structures, which also may heat the converter chambers, particularly if the C-converter is operated in combination with a hydrocarbon converter operated with plasma or with thermal energy.
In one embodiment of the C-converter, gaps are formed between the converter chambers, and the gaps are connected with an inlet and an outlet, which allow to pass a fluid through the gaps. If the second gas is directed through the gaps into the converter chambers, the second gas may be preheated, which contributes to energy savings during operation of the C-converter. If the second gas is steam of water, the steam of water may be produced by injecting liquid water into the gaps during operation. As the converter chambers have a temperature of several hundred degrees Celsius, the liquid water will be vaporized.
In a preferred embodiment, the diverting device comprises at least one aerosol diverting device and at least one gas diverting device. The aerosol diverting device preferably comprises a slide valve or a flap valve. Thus depositions of particles during operation are avoided or at least reduced.
In one embodiment, the each of the converter chambers comprises at least one converter chamber inlet, wherein at least a fraction of the converter chamber inlets of at least two converter chambers is located on a circle. At least one diverting device comprises a rotatable diverting element. Thus, the aerosol converter inlet may be connected to at least one converter chamber inlet via the rotatable diverting element. Thus, the aerosol may be diverted quickly, and a continuous operation of the C-converter may be ensured.
In a preferred embodiment, each of the converter chambers comprises at least one converter chamber outlet, wherein the discharging device for each converter chamber comprises a valve assembly having at least one valve for each converter chamber, wherein the valve assembly is adapted to alternately connect at least one of the at least two converter chamber outlets a) with the first C-converter outlet, or b) with the second converter outlet or c) to disconnect converter chamber outlets from the first and second converter outlets. By use of gas valves, commercially available parts may be used, which reduces costs of the C-converter.
The above mentioned problem is also solved by an apparatus for producing CO or synthesis gas, comprising: at least one hydrocarbon converter operated with plasma or with thermal energy, the hydrocarbon converter having an outer casing and being adapted to decompose fluids containing hydrocarbon into carbon and hydrogen; and at least one C-converter. The C-converter is disposed adjacent to the outer casing of the hydrocarbon converter so as to facilitate a heat transfer from the hydrocarbon converter to the C-converter. During operation of the apparatus, hot aerosol and the second gas are alternately directed to the chambers of the C-converter, and the C-converter converts particles containing carbon into CO or synthesis gas at high temperatures. Heat transfer between the C-converter and the outer casing of the hydrocarbon converter ensures that an additional heater may be avoided or at least reduced in size. Preferably, the at least one C-converter of the apparatus is implemented according to the above mentioned embodiments.
A preferred embodiment of the apparatus comprises a plurality of adjacent hydrocarbon converters wherein at least one gap is formed between the hydrocarbon converters, and wherein one or more converter chambers of at least one C-converter is/are disposed in the at least one gap. Thus, good energy utilization during operation of the apparatus and small installation space may be achieved due to close packing
In one embodiment of the apparatus, the C-converter partially or completely surrounds the hydrocarbon converter at its periphery. Preferably, the C-converter concentrically surrounds the outer casing of the hydrocarbon converter. Thus, a particularly compact construction of the apparatus may be realized, which has good energy utilization during operation.
In one embodiment of the apparatus, fluid conduits are disposed on or in the outer casing of the hydrocarbon converter. Thus, a cooling feature may be provided for the hydrocarbon converter and/or a fluid may be preheated. Preferably, the outer casing of the hydrocarbon converter is free from fluid conduits in a region facing an adjacent C-converter. Thus, cooling of the outer casing of the hydrocarbon converter and at the same time heat transfer to an adjacent C-converter may be achieved.
In a preferred embodiment of the apparatus, at least one of the gaps is connected to an inlet and to an outlet. Thus, a fluid may be directed through the gaps, such that heat transfer between a fluid in the converter chamber and a fluid in the gaps is facilitated. Thus, any structures located near to the hot converter chambers may be cooled, if the fluid is colder than the neighboring structures. If the second gas is directed through the gaps before the second gas is directed into the converter chambers, the second gas may be preheated, which contributes to energy savings during operation of the C-converter. If the second gas is H2O steam, said H2O steam may be produced by injecting liquid water into the gaps during operation. Since the converter chambers have a temperature of several hundred degrees Celsius, the liquid water is vaporized.
The above mentioned problem is further solved by a method for operating a C-converter, the C-converter comprising a plurality of converter chambers wherein each of the converter chambers comprises at least one filter, the filter being adapted to filter particles from an aerosol comprising a first gas and particles The method comprises the steps of: Alternately supplying an aerosol containing carbon into at least one first converter chamber or at least one second converter chamber, thereby trapping the particles from the aerosol in the filter, until a desired particle filling degree in the respective converter chamber is reached; and alternately supplying a second gas into the at least one first converter chamber or the at least one second converter chamber so as to regenerate the corresponding converter chamber by converting the particles containing carbon into carbon monoxide, wherein a) the second gas is CO2 and the conversion is carried out according to the equation C+CO2→2CO; or b) the second gas is H2O steam and the conversion is carried out according to the equation C+H2O→CO+H2. Aerosols containing carbon particles may be converted by use of this method without any interruptions, and a higher conversion degree of the materials directed into the converter may be achieved.
Preferably, the second gas supply is blocked when the aerosol is supplied to the respective converter chamber, and the first gas is exhausted via a first converter chamber outlet. When the second gas is supplied to the respective converter chamber, the aerosol supply is blocked and the carbon monoxide is exhausted via a second converter chamber outlet.
In one embodiment of the method, the maximum particle filling degree is determined by at least one of the following: a pressure difference across a converter chamber supplied with aerosol, an increase in weight of the converter chamber supplied with aerosol, a filling sensor output, a duration of supplying the aerosol or by a time period of supplying aerosol, and depending on the current particle filling degree of another converter chamber.
In one embodiment of the method, the second gas is supplied until another desired particle filling degree is reached. The other desired particle filling degree is lower than desired particle filling degree. Accordingly, a continuous operation may be achieved.
The method is preferably carried out such that the C-converter is continuously supplied with the aerosol. Thus, the C-converter may cooperate with an aerosol source continuously supplying aerosol even though the converter chambers are alternately supplied with aerosol or the second gas, respectively.
In the method, conversion of C to CO preferably takes place at a temperature above 800° C., wherein a first converter chamber is heated at least partially by at least one of waste heat from at least one adjacent second converter chamber, waste heat of a hydrocarbon converter operated with plasma or with thermal energy and the aerosol. During operation, hot aerosol is alternately directed into the converter chambers and, as soon as the converter chambers are filled to a predetermined particle filling degree with particles containing carbon, the converter chambers are regenerated by supplying the second gas at a high temperature. Heat transfer between adjacent converter chambers prevents a high heat loss during regeneration periods. An additional heater for maintaining the temperature above 800° C. may be avoided or at least reduced in size.
In one embodiment, gaps are formed between the converter chambers, and the method comprises the step of directing a fluid through the gaps such that a heat exchange between a fluid in the converter chambers and the fluid in the gaps may be achieved. Thus, any structures located next to the hot converter chambers may be cooled. If the second gas is directed through the gaps before the second gas is directed into the converter chambers, the second gas may be preheated. If the second gas is H2O steam, the H2O steam may be produced by injecting liquid water into the gaps during operation, wherein the liquid water becomes vaporized at temperatures well above the boiling point of 100° C.
Preferably, the aerosol and the second gas are supplied to the converter chamber from opposite sides of the filter, and the first and second converter chamber outlets are arranged on opposite sides of the filter. Thus, the trapped particles may be released from the filter.
A method for operating the above discussed apparatus also solves the above mentioned problem. The method comprises the step of directing a fluid through the gaps between the C-converter and/or the converter chambers of the C-converter and/or the outer casing of the hydrocarbon converter such that a heat exchange is effected between a fluid in the converter chambers and/or in the outer casing and the fluid in the gaps. Thus, any structures next to the hot converter chambers may be cooled. If the second gas is directed through the gaps, the second gas may be preheated. If the second gas is H2O steam, said H2O steam may be produced by injecting liquid water into the gaps during operation and vaporizing the liquid water.
The invention and further details and advantages thereof will be discussed herein below based on preferred embodiments and referring to the figures.
It shall be noted that the terms top, bottom, right and left, as well as similar terms as used in the following description relate to the orientations and arrangements, respectively, as shown in the figures and these terms are only meant to be descriptive of the embodiments and should not be interpreted in a limiting manner although they may refer to preferred arrangements.
Furthermore, a filter 13 is disposed in each of the two converter chambers 10 (a filter 13a in the first converter chamber 10a and a filter 13b in the second converter chamber 10b). The Filters 13 are adapted to trap particles from aerosol directed therethrough. In particular, the filters 13 may trap particles containing carbon from the aerosol, which particles may later be converted by means of a second gas, such as CO2 or H2O-steam, as will be described in more detail herein below.
Each of the converter chambers 10 of
The C-converter 1 comprises an aerosol diverting device 16 located between the aerosol converter inlet 3 and the converter chambers 10. The diverting device 16 is configured to selectively connect the aerosol converter inlet 3 with either the first converter chamber 10a or the second converter chamber 10b. The C-converter 1 further comprises a gas diverting device 17 located between the converter gas inlet 5 and the converter chambers 10. The gas diverting device 17 is adapted to selectively connect the converter gas inlet 5 with either the first converter chamber 10a or the second converter chamber 10b. Alternatively, the aerosol diverting device 16 and the gas diverting device 17 may also be formed as a single combined diverting device (not shown in
As indicated above, the aerosol converter inlet 3 is connected to a source of aerosol (not shown in
The converter gas inlet 5 is connected to a source of a second gas (not shown in
If the second gas is a gas containing CO2 (which may also be pure CO2), said second gas may for example be an exhaust gas from an industrial plant, a power plant, a cement plant, a furnace gas from a (blast) furnace, an exhaust gas from an internal combustion motor or any other combustion process or any other gas containing CO2. It will be obvious to the skilled person that such a gas containing CO2 may also comprise significant portions of other components which may not participate in the reactions inside the C-converter 1 (see below), such as but not limited to nitrogen or inert gases. Furthermore, the gas containing CO2 may comprise minor proportions (less than 5%) of components which may participate in the reactions inside the C-converter 1. However, due to their low proportions, they are not detrimental to the functionality of the C-converter 1 and do not have considerable influence on the conversion processes therein.
If the second gas is H2O steam (water vapor), such water vapor may be specifically produced for operating the C-converter 1, for example from water supplied for this purpose or the water vapor may come from a cooling process, for example from a cooling tower of a power plant or another industrial plant. Similar to the gases containing CO2, the water vapor may comprise considerable amounts of components which do not participate in the reactions inside the C-converter 1, such as nitrogen or inert gases, and may also comprise low proportions (less than 5%) of reactive components which do not have a considerable influence on the conversion process.
Depending on the type of the supplied second gas, the following conversions take place inside the C-converter 1 without using catalysts, as will be described in more detail below:
a) if water vapor is supplied: C+H2O→CO+H2
b) if carbon dioxide is supplied: C+CO2→2CO.
If water vapor is supplied, the C-converter 1 produces a CO/H2 gas mixture which is also referred to as a synthesis gas. If CO2 is supplied, the C-converter 1 produces CO or a gas containing CO (possibly having inert components or a low proportion of reactive components (less than 5%)), respectively.
The structure and operation of the C-converter 1 will be described herein below for a case wherein a gas containing CO2 is supplied as a second gas through the converter gas inlet 5, and wherein the above mentioned conversion b) is carried out (Boudouard conversion according to the Boudouard equilibrium).
In a first step, filtering is performed by passing the aerosol through one of the converter chambers. The filter traps the particles containing carbon and passes the H2 which may be appropriately discharged and preferably collected for other purposes. The filtering step is stopped by stopping the flow of aerosol through the respective converter chamber. In a second step a conversion (also called a regeneration) is performed by passing the second gas (in this case CO2) through the respective converter chamber. In the conversion, the second gas converts the previously trapped particles containing carbon as disclosed above. The conversion typically takes place at a temperature above 850° C. without utilizing a catalyst.
Filtering and conversion are controlled to alternately take place in the converter chambers 10a and 10b, as will be described in more detail herein below. The position of the aerosol diverting device 16 and the gas diverting device 17 are controlled based on the filling degree of particles in the converter chambers 10. In particular, they are controlled to supply the first and second converter chambers 10a and 10b in an alternating manner with the aerosol and the second gas. In other words, the converter chambers are always only supplied with either the aerosol or the second gas and when the converter chamber 10a is supplied with the aerosol, the converter chamber 10b is supplied with the second gas and vice versa. The discharging device 18 connects the respective converter chambers 10a, 10b with the converter outlet 7, when aerosol is supplied thereto, and to the converter outlet 9, when the second gas (gas containing CO2, H2O steam) is supplied.
The filters 13 in the converter chambers 10a and 10b may be filled with particles between a lower desired particle filling degree and an upper desired particle filling degree (also called a desired minimum and maximum particle filling degree). The filling degree depends on the amount of particles containing carbon, which are trapped in the filters 13 (13a, 13b in
If a desired maximum particle filling degree of the (first) converter chamber 10a on the left hand side in
In this case, the desired minimum particle filling degree is a predetermined particle filling degree which can be reached after a desirable regeneration time and which provides for sufficient capacity for storing new particles containing carbon in the respective filters in the converter chambers. The minimum particle filling degree may be 0% but may be also a particle filling degree where the filters 13 are loaded with particles containing carbon up to 5-15 percent of the rated filter load. In the above example having two converter chambers 10a, 10b, the flow of the aerosol and of the second gas through the respective converter chambers 10a, 10b is preferably controlled in a manner such that the trapping of particles and the conversion thereof occur approximately at the same speed. This enables a continuous operation of the C-converter.
In the example of
In
In
As the skilled person will appreciate, depending on the rotational position of the guiding element 23, the inclined conduit 25 will directed the aerosol to one of the converter chamber inlets 11a or 11b or 11c or 11d. In
As mentioned above, the C-converter 1 comprises a plurality of converter chambers 10, i.e. at least two converter chambers 10. With respect to the converter chambers 10, the indices a, b, c, d and so on are used for referring to a particular converter chamber 10. The respective inlets, outlets, filters and other associated elements of the converter chambers 10 will also have the same indices a, b, c, d and so on (for example filter 13a, 13b, 13c). Furthermore, the indices a, b, c, d may be used for describing a specific switching sequence for delivering aerosol/gas to the plurality of converter chambers 10 during operation. In the position of the guiding element 23 of
The converter chamber inlets 11a-11d are converter chamber inlets 11 of a C-converter 1 having four converter chambers 10. Alternatively, the four converter chamber inlets 11a-11d could lead to two different C-converters, each having two converter chambers 10 (not shown). In such a case the converter chamber inlets 11a and 11c, shown in
Furthermore, it is considered that the outlet of the conduit 25 may be sized to cover more than one converter chamber inlet 11a-11d in each rotational position. The conduit 25 could for example supply aerosol to two converter chamber inlets 11 (11a and 11d in
Generally, the gas diverting device 17 may be constructed similar to the above aerosol diverting device 16. However, it is considered to implement the gas diverting device 17 simply as an assembly of one or more gas valves, wherein the second gas (i.e. gas containing CO2, H2O steam) may be selectively supplied into the converter chambers 10 via the gas valves. In this way, a simple construction including standard hardware may be used.
The discharging device 18 is adapted to connect the converter chambers 10 (10a and 10b in
The discharging device 18 is constructed similar to the gas diverting device 17 and comprises a system of valves, connector conduits and distributor conduits. The discharging device 18 comprises an H2 manifold 35 which is connected to the first converter outlet 7 for H2. Furthermore, the discharging device 18 comprises a CO manifold 37, which is connected to the second converter outlet 9 for CO. The H2 manifold 35 is connected to each one of the converter chambers 10 by means of a plurality of H2 connector conduits 39. The CO manifold 37 is connected to each one of the converter chambers 10 by means a plurality of CO connector conduits 41. H2 gas valves 43 are disposed in the H2 connector conduits 39, and CO gas valves 45 are disposed in the CO connector conduits 41.
By means of the discharging device 18, each of the converter chambers 10 may be connected to the first converter outlet 7 and the second converter outlet 9 in an alternating manner. Particularly, any converter chamber 10 may be connected to or disconnected from the H2 manifold 35 (leading to the converter outlet 7) by opening or closing, respectively, one or more of the respective H2 gas valves 43. In the same way any converter chamber 10 may be connected to or disconnected from the CO manifold 37 (leading to the converter outlet 9) by opening and closing, respectively, one or more of the associated CO gas valves 45. It is noted that a plurality of converter chambers 10 may be simultaneously connected to the respective converter outlets 7 and 9, depending on the respective supply status. As mentioned above, the number of converter chambers 10 of the C-converter 1 is not limited to a particular number, and the shown configurations and numbers are merely examples.
During operation, the converter chamber 10 is typically held at a high temperature of several hundred degrees Celsius, preferably at a temperature of higher than 850° C. The desired temperature depends on the conversion reactions taking place inside the converter chambers 10, and the temperature is preferably higher than 850° C. when converting C and CO2 into CO (the second gas from the converter gas inlet 5 is gas containing CO2). Therefore, the converter chambers 10 are made of a heat resistant material, such as ceramics and/or metal. Furthermore, the filter 13 located inside the converter chambers 10 is made of a heat resistant material. The filter 13 may for example be a mesh filter or a ceramic filter. The converter chambers 10 may also comprise a porous ceramic base, which acts as a filter 13. Thus, the filter 13 may be separate from the housing of the converter chambers 10 or may be integrated therewith.
In all embodiments of
In the arrangement shown in
In
In the embodiment of
The second converter chamber inlet 12 is located such that a gas supplied thereby may pass through the filter 13 in a flow direction opposite to the flow direction of the aerosol. When supplying the aerosol, a filter cake, is formed by the particles containing carbon, which are trapped in the filter. When the second gas is supplied, the filter cake will be detached from the filter 13 by passing the second gas through the filter in a direction of flow opposite to the direction of flow of the aerosol. This reverse flow may lead to an improved detachment of particles and thus good reactivity of the particles with the second gas will be ensured. A respective converter chamber may thus be regenerated faster.
Depending on the size of the particles containing carbon, a secondary aerosol comprising the second gas and the particles containing carbon may exit from the converter chamber outlet 15. In other words it is possible that the conversion of detached particles is not complete before the particles exit via the second converter chamber outlet 15. However it is contemplated that such particles may be present only over a short distance, in a respective conduit (not shown) connected to the second converter chamber outlet 15. However, such secondary aerosol including the second gas and the particles containing carbon will likely be converted completely into CO in such a conduit. Depending on the type of second gas, the secondary aerosol will comprise CO2 , particles containing carbon and CO (if the second gas contains CO2) or H2O steam, particles containing carbon, H2 and CO (if H2O steam is supplied as the second gas).
Operation of the C-converter 1 will be described with reference to
At first, the first converter chamber 10a will be supplied with aerosol comprising particles containing carbon (C-particles) and hydrogen H2 via the aerosol converter inlet 3 and the aerosol diverting device 16. The aerosol is produced by a hydrocarbon converter which operates with thermal energy or plasma, preferably a Kvaerner-reactor. In the described example, the aerosol coming from the hydrocarbon converter has a high temperature of for example 1200 to 1800° C., as the hydrocarbon converter is of the type which operates with a high temperature plasma. In other examples, where the aerosol is delivered from an aerosol storage container or where the hydrocarbon converter is operating with low thermal energy or with a low temperature plasma, the aerosol may have a temperature of below 850° C. (but typically of at least 300° C.). If the aerosol is directed into the C-converter 1 at a temperature of less than 850° C. the aerosol will be heated to a temperature of more than 850° C. prior to supplying into the converter chambers 10 or will be heated inside the converter chambers 10. Suitable heaters may be provided either for heating the ductwork leading to the converter chambers 10 or for heating the converter chambers 10 or at least parts thereof. In the following description, as indicated above, the aerosol is considered to come from a high temperature hydrocarbon converter.
The aerosol consisting of hot particles containing carbon (C-particles) and hot H2 gas, flows into the first converter chamber 10a and heats the converter chamber. The hot particles containing carbon are trapped by the filter 13a of the first converter chamber 10a. The longer the aerosol is supplied into the first converter chamber 10a the more particles containing carbon will deposit in the filter 13a until a desired maximum particle filling degree is reached. The first converter chamber outlet 14 is open and H2 which freely passes through the filter 13 is directed to the first converter outlet 7 for H2 via the discharging device 18.
The desired maximum particle filling degree may for example be determined based on a pressure difference across the converter chamber 10, based on an increase in weight of the converter chamber 10 or by means of another measurement. The particle filling degree may for example be determined by means of an optical sensor, which recognizes a filling height, by means of an ultrasonic sensor or by means of similar known sensors. Alternatively, the particle filling degree may be determined by using a high frequency sensor which senses variation of high frequency signals which are directed through a converter chamber 10 wherein the characteristics thereof change depending on the particle filling degree of the converter chamber 10. The desired maximum particle filling degree may also be defined based on a predetermined cycle time of switching between filling and regenerating the converter chambers 10.
When the desired maximum or predetermined filling degree of the first converter chamber 10a has been reached, the aerosol diverting device 16 switches and supplies the second converter chamber 10b with aerosol. Due to the supply of hot aerosol, the second converter chamber 10b will be heated in the same way, and the filter 13b of the second converter chamber 10b will accumulate particles containing carbon over time up to a desired maximum particle filling degree.
After switching the aerosol supply to the second converter chamber 10b, the second gas, i.e. gas containing CO2, is supplied into the previously filled first converter chamber 10a for regeneration. The gas containing CO2 is supplied from the converter gas inlet 5 and via the gas diverting device 17, for example via the gas inlet valves 33 shown in
The carbon monoxide CO generated in the converter chamber 10a will be discharged from the converter chamber 10a and is directed to the second converter outlet 9 for carbon monoxide CO via the discharging device 18. Discharging may for example take place via the above mentioned connector conduits 41 and the manifold 37 (see
The gas containing CO2 is supplied into the corresponding converter chamber 10 to be regenerated until the converter chamber reaches a desired minimum particle filling degree. The desired minimum particle filling degree may be 0%, however does not have to be 0%, since it is not always economically viable to completely convert the C-particles into CO during operation. The desired minimum particle filling degree may be determined based on a predetermined cycle time of switching between filling and regenerating the converter chambers 10. Alternatively, the desired minimum particle filling degree may be determined based on a sensor output, for example based on a pressure drop, based on a decrease in weight and so on. The measurements for the desired maximum and minimum particle filling degree may be obtained by means of the same sensors and devices mentioned above.
Furthermore, supplying the aerosol (filtering or filling) and supplying the second gas (regenerating) into a converter chamber 10 may be switched based on the fact that another converter chamber 10 has reached a desired minimum or maximum particle filling degree. As an example, if one of the converter chambers 10 currently supplied with gas containing CO2 has already been regenerated to the desired minimum particle filling degree, the supply of aerosol may already be switched to the regenerated converter chamber 10 before another currently supplied converter chamber 10 has reached its desired maximum particle filling degree. If a currently supplied converter chamber is filled to the desired maximum particle filling degree and cannot be filled any more, switching the supply of aerosol to a next converter chamber may be carried out.
In all embodiments, the amount and the size of the converter chambers 10 is chosen in such a way that the C-converter 1 may be continuously supplied with aerosol. The switching operations for sequentially supplying one or more of the converter chambers 10 with aerosol are carried out based on the filling degree of the converter chambers 10 and the supplied volume of the aerosol per time period. As mentioned above, also a plurality of converter chambers 10 may simultaneously be supplied with aerosol. Also a plurality of converter chambers 10 may simultaneously be supplied with gas containing CO2 and, thus, may simultaneously be regenerated. As an example, two converter chambers 10 (for example 10a and 10b in
The time during which a converter chamber 10 is filled until reaching the maximum particle filling degree does not necessarily have to correspond to the time during which a converter chamber filled to the maximum is regenerated by feeding the gas containing CO2. As an example, a situation will be described wherein the regeneration of a converter chamber 10 by feeding gas containing CO2 takes twice the time as filling the converter chamber 10 up to a maximum particle filling degree. In such a situation, the C-converter 1 has for example three converter chambers 10a, 10b, 10c. Lets consider that the first converter chamber 10a has just been filled with aerosol and that the gas containing CO2 is currently supplied into the first converter chamber 10a. The first converter chamber 10a may now be regenerated over two time periods (for example two minutes) by supplying gas containing CO2. At the same time the second converter chamber 10b (during the first time period) and then the third converter chamber 10c (during the second time period) will be supplied with aerosol. When the two other converter chambers 10b and 10c have been filled with aerosol and have reached the respective desired maximum particle filling degree, their respective regeneration begins by supplying the gas containing CO2. That means, that regeneration of the second converter chamber 10b begins at the beginning of the second time period, and regeneration of the third converter chamber 10c begins following the second time period (the beginning of a third time period). Since regenerating the first converter chamber 10a takes two time periods (for example two minutes), the other two converter chambers 10b and 10c could be filled up to the desired maximum particle filling degree during said regeneration time (i.e. two converter chambers having each a filling time of one time period). Since the first converter chamber 10a is sufficiently regenerated after supplying the gas containing CO2 for two minutes and therefore comprises the desired minimum particle filling degree, the aerosol diverting device 16 switches again to the first converter chamber 10a and begins to fill the first converter chamber. At this point in time, the second converter chamber 10b is half regenerated, and regeneration of the third converter chamber 10c has just begun.
The operation described above also works if several converter chambers 10 are simultaneously supplied. Instead of the above described three converter chambers 10 (for a regeneration time which is twice compared to the filling time) also six converter chambers 10 may be provided, wherein two converter chambers 10, respectively, are simultaneously filled with aerosol. In this case, two converter chambers 10 will switch as a pair at each switching step between supply with aerosol or supply with the second gas. If several converter chambers 10 are filled simultaneously, these numbers multiply.
The above described example wherein the regeneration takes twice the time is an arbitrary example. Structure and operation may be adapted to other timings, as will be obvious to the skilled person. As an example, four converter chambers 10 may be provided if the regeneration time is triple the filling time, or five converter chambers 10 may be provided if the regeneration time is quadruple the filling time. If two or more converter chambers 10 are concurrently filled or regenerated, the above mentioned numbers double or multiply. The skilled person will choose the amount and capacity of the converter chambers based on the time periods which are actually to be expected during operation. Although continuous operation of the converter chamber is most desired, both the filling and the regeneration may be discontinuous, i.e. intermittent. When used in combination with a hydrocarbon converter which continuously supplies the aerosol, it is beneficial if at least the filling operation is continuous, i.e. at least one chamber is always being filled. The regeneration on the other hand may be discontinuous, i.e. there may be periods in time, where no chamber is currently regenerated. While CO2 or water/water vapor may be easily stored or buffered, the aerosol cannot be stored quite as easily.
As was described above, the converter chambers 10 are arranged side by side such that the converter chambers may heat each other by their waste heat. The second gas (gas containing CO2, H2O steam) or another fluid may be directed through the gaps 47 between the converter chambers 10 and/or between the converter chambers 10 and the shell 49 (
If the second gas is H2O steam, the structure of the C-converter 1 is the same as described above. The difference is that H2O steam is supplied via the converter gas inlet 5 instead of a gas containing CO2. In this case, the carbon of the particles containing carbon will be converted into carbon monoxide and hydrogen according to the equation C+H2O→CO+H2. Accordingly, in this case a gaseous carbon monoxide/hydrogen mixture is produced in the converter chambers 10, and said mixture exits from the C-converter outlet 9.
In the following, an apparatus 58 for producing carbon monoxide CO is described. The apparatus 58 comprises a C-converter 59 as well as a hydrocarbon converter 60 operated with plasma or with thermal energy, preferably a Kvaerner-reactor. In a basic embodiment, the hydrocarbon converter 60 is cylindrical and has a circular cross section, as shown in
The C-converter 59 comprises an encasement 64 which surrounds the outer casing 62 of the hydrocarbon converter 60. The outer casing 62 of the hydrocarbon converter 60 and the encasement 64 of the C-converter 59 form an annular space which serves as converter chamber 10 of the C-converter 59. In
Since the C-converter 59 is concentrically arranged with respect to the outer casing 62 of the hydrocarbon converter 60, the waste heat from the hydrocarbon converter 60, which is radiated from the outer casing 62, will be transferred to the C-converter 59. Thus, it is possible to operate the C-converter 59 at the desired high temperatures of more than 850° C. without the need for an additional dedicated heating device or if at all a heating device which may have low power.
As shown in
The apparatus 58 for producing CO preferably comprises the above described C-converter 1, which comprises a plurality of converter chambers 10. FIG. 8a shows an embodiment of the apparatus 58 for producing CO similar to the one shown in
In the embodiments of
A first embodiment of the C-converter 1 is disposed in a gap in the center between the cylindrical hydrocarbon converters 60. The C-converter 1 located in the center comprises four converter chambers 10, wherein each converter chamber is cylindrical and wherein the converter chambers are disposed as a tube bundle near to the corresponding outer casing 62 of the four hydrocarbon converters 60.
A second style of C-converters 1′ is disposed in a gap between the shell 49 and the cylindrical outer casing 62 of two adjacent hydrocarbon converters 60, respectively. The second style of C-converters 1′ comprises two tubular converter chambers 10′ having a triangular cross section and being arranged as a tube bundle next to each other and near to the outer casings 62. The gaps 47 act as conduits for a fluid, particularly for the second gas (gas containing CO2, H2O steam).
As explained above, the hydrocarbon converters 60 produce hot aerosol comprising hydrogen H2 and particles containing carbon during operation, wherein the aerosol is alternately supplied to the converter chambers 10, 10′ of the C-converters 1, 1′ via one or more aerosol diverting devices 16 (not shown in
While the apparatus for producing CO was described with reference to
The C-converters 1, 1′ shown in
The hydrocarbon converters 60 also have an outer casing 62, having a plurality of fluid conduits 66 located therein. An inlet and an outlet (not shown) for the fluid conduits 66 are provided to enable a fluid to be directed through the fluid conduits 66. The fluid conduits 66 may be arranged in any desirable pattern in the outer casing 62 so as to achieve a good heat transfer of waste heat to the fluid. The pattern may for example be straight, in serpentines, spirally around the outer casings 62 and so on. If the fluid is the second gas (CO2, H2O steam), it is preheated by the waste heat of the corresponding hydrocarbon converter 66. As shown in
As best seen in
In all embodiments of the apparatus 58, the conduits and gaps 47 are constructed in such a way that good heat transfer is obtained. In all embodiments of the apparatus 58, the pressure, the flow rate and other characteristics of the fluids directed therethrough are chosen during operation such that a good heat transfer and a good energy transfer is obtained. The pressure, the flow rate and other characteristics of the fluids directed therethrough are also controlled to enable good filtering and regeneration in the respective converter chambers. In particular, the flow rate and temperatures of the aerosols and the second gas are matched to allow filtering and regenerating steps to be completed at desired time intervals. As described above, the desired time intervals may be equal but may also differ from each other.
The invention has been described with reference to preferred embodiments, wherein the individual features of the described embodiments may be unrestrictedly combined and/or exchanged as long as these features are compatible. Also individual features of the described embodiments may be omitted, as long as these features are not essential. For the skilled person numerous variations and other embodiments would be possible and obvious without leaving the scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2013 013 443.9 | Aug 2013 | DE | national |
This application corresponds to PCT/EP2014/025004, filed Aug. 12, 2014, which claims the benefit of German Application No. 10 2013 013 443.9, filed Aug. 12, 2013, the subject matter of which are incorporated herein by reference in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2014/025004 | 8/12/2014 | WO | 00 |
