Patent Application
20240375962
The present invention concerns a method and system for treating carbon dioxide (CO2) exhausted by CO2 producing installations, preferably blast furnaces, thereby recovering carbon monoxide (CO). The present invention is particularly applicable to CO-consuming methods and systems, such as iron extraction methods and systems.
Blast furnaces are the main tool of metallurgy. They operate on the principle of chemical reduction, where metal ores are reduced to their main metal components by reacting with gases or other solids at high temperature. The most common reduction reaction is the reduction of iron ore, typically in the form of ferric oxide (Fe2O3) with CO to iron (Fe) and CO2:
Fe2O3+3 CO→2 Fe+3 CO2
As can be seen from the reaction, for every ton of iron (Fe), approx. 1.2 tons of CO2 are produced. Indeed, nearly 7% of the global CO2 emissions emerge from steel production. In the light of the efforts for CO2 emissions reduction, the present invention aims to provide a means to reduce, and even eliminate, the CO2 emission footprint of the steel industry.
In fact, the present invention aims to reduce CO2 emissions of applications which consume CO. Hereto, the present invention particularly aims to provide a method and system for recovering CO from CO2, such as is produced in blast furnaces to produce iron from iron ore.
A prior art method for producing CO from CO2 is disclosed in U.S. Pat. No. 4,190,636A. This document discloses an improved method of producing carbon monoxide in a plasma arc reactor, wherein carbon dioxide is delivered to an arc to form a plasma into which solid carbon is delivered. The products are quenched and filtered to yield carbon monoxide.
The present invention relates to a novel plasma-based system as a solution to reduce CO2 emission, in particular the CO2 emission footprint of the steel industry. Thereto, the present invention relates to a method and a system for producing carbon monoxide (CO) as disclosed in claims 1, 2 and 5. The invention also concerns an iron production method and an iron production system as disclosed in claims 6 and 7. Further embodiments of the invention are disclosed in the dependent claims and further in this document.
Low-temperature plasmas are known for their chemical reactivity. An atmospheric discharge in CO2 gas will produce the following reaction:
CO2→CO+O ΔH=283 kJ/mol
Hence, it seems that a plasma reactor is a viable method for CO recovery from CO2 emissions. Practically, the CO2 emissions can be:
It is a particular advantage that the plasma reactor may operate entirely using electricity, which may be produced eco-friendly, e.g. via solar power or wind power. The present invention presents several crucial advantages compared to the traditional techniques used in e.g. blast furnace operation:
The present invention will now be discussed in more detail, with reference to the figures.
In a first aspect, the present invention thereto relates to a method for producing carbon monoxide (CO), comprising the steps of:
The present invention also relates to a system for producing carbon monoxide, comprising:
In a second aspect, the present invention relates to an iron production method comprising the steps of:
The invention also relates to an iron production system comprising:
In a preferred embodiment, the present invention relates to a method for producing carbon monoxide (CO), comprising the steps of:
In a further preferred embodiment, the present invention relates to a method for producing carbon monoxide (CO), comprising the steps of:
In an embodiment, the reaction chamber comprises carbon donor particles and/or the method of the present invention comprises the step of adding carbon donor particles in the reaction chamber. This allows the oxygen radicals (O) in the plasma reaction CO2→CO+O, to bind with the carbon of the carbon donor particles to form CO, thereby increasing the CO yield of the plasma process. As a result, the output stream will comprise less oxygen (O2) and a separation stage for separating the O2 from the final output stream may not be necessary.
In an embodiment, the carbon donor particles are added to the gaseous initial input stream. In another embodiment, the carbon donor particles are supplied to the plasma reactor by a separate inlet. In another embodiment, carbon donor particles are supplied to the plasma reactor in the plasma afterglow section of the plasma reactor. In another embodiment, carbon donor particles are provided subsequent to the plasma reactor. Preferably, carbon donor particles are supplied to the plasma reactor in the plasma afterglow section of the plasma reactor or immediately subsequent to the plasma reactor. The presence of reactive oxygen radical species and high temperatures are beneficial for rapid reaction to CO. By providing the carbon donor particles in the plasma afterglow, but not the plasma itself, saves energy as well as operational difficulties related to including carbon particles in the plasma phase.
In a preferred embodiment, the present invention relates to a method for producing carbon monoxide (CO), comprising the steps of:
In a preferred embodiment, the particles are carbon particles in the form of a fine powder. These can be preferably supplied through an additional inlet with a carrier gas, such as air, or together with the main CO2 supply. The methods will most likely differ, as one will aid conversion in the post-plasma region (additional inlet), and the other will influence the plasma chemistry in the discharge itself. For instance, carbon particles in the plasma may facilitate faster CO formation, but, on the other hand, consume molecular oxygen (O), which normally contributes to the CO2 splitting process (neutral impacts). Carbon particles preferably have sizes with an average radii of between 0.05 and 0.5 mm. In a preferred embodiment, the carbon donor particles are in a fluidized state. In still another embodiment, a down flow of carbon-donor particles is created, preferably under the influence of gravity, while the down flow of carbon-donor particles is exposed to O radicals, preferably in counter-flow to the down flow.
In a preferred embodiment, the carbon-donor particles are positioned in a fixed bed. The fixed carbon bed can preferably be optimized using fluid dynamics and plasma model simulations, and the main focus can be at increasing the residence time inside the carbon bed, and achieving optimum reaction temperature (preferably at least 1500K). Furthermore, the carbon particles size and shape, and the overall carbon volume can preferably be optimized. Streaming CO2 through a carbon (coal) filter can already produce the main valuable chemical-CO, given that the reaction temperature is right. The Boudouard reaction needs at least 1500K in order to activate. In practice, this is achieved through heating of the carbon bed (though gas burning or electrical heaters). However, the plasma jet generator of the present invention has the advantage that it heats up the gas already-typically to even more than 3000K can be measured inside the plasma discharge. Plasma discharges are a very efficient way of warming up a gas, as they do not rely on additional convective heating elements. Furthermore, the gas in the reactor is already converted to some extent. The plasma conditions further create even more radicals, CO radicals and O radicals, which are highly reactive thereby increase efficiency.
Converting oxygen radicals and/or O2 to CO and/or CO2 is particularly advantageous to produce CO as well as use of said CO in a blast furnace. Conversion of O2 in a gas stream comprising O2/CO/CO2 prevents the energy intensive separation of oxygen while increasing the CO yields per pass. Furthermore, presence of carbon particles in the presence of high temperature conditions in or subsequent of the plasma reactor allow for CO2 and carbon to CO conversion through the reverse Boudouard reaction; further increasing the CO yield.
In a preferred embodiment, the present invention relates to a method for producing carbon monoxide (CO), comprising the steps of:
Advantageously, the removal of (most) oxygen from the plasma stream by fixation with carbon donor particles allows the separation of a predominantly binary rather than tertiary system. This allows for far easier and cheaper separation. In a further preferred embodiment, CO and CO2 are separated with cryogenic distillation, cryogenic flash or pressure-swing absorption (PSA). More preferably, CO and CO2 are separated with cryogenic flash. Advantageously, a single stage vapor/liquid separation method is considerably simpler, requires smaller, less technologically advanced equipment as well as lower energy requirements than cryogenic distillation. The inventors surprisingly found cryogenic distillation is sufficient to purify the CO-rich separator outlet to 99 wt. % CO. For purities over 99.99%, cryogenic distillation is likely preferred. For blast furnace applications this additional purity does not weigh up against the additional energy requirements.
In a further preferred embodiment, CO and CO2 are separated with a cryogenic flash or cryogenic distillation, more preferably a cryogenic flash. In preferred embodiment, the cryogenic flash or distillation operates at a temperature of at most −100° C., more preferably at most −110° C., more preferably at most −120° C., more preferably at most −130° C., more preferably at most −140° C. In a preferred embodiment, the cryogenic flash operates at a temperature of at least-180° C., more preferably at least −170° C., more preferably at least −160° C., more preferably at least −150° C. In preferred embodiment, the cryogenic flash or distillation operates at a pressure of at least 10 bar, more preferably at least 20 bar, more preferably at least 24 bar, more preferably at least 25 bar, most preferably about 26 bar. In preferred embodiment, the cryogenic flash or distillation operates at a pressure of at most 50 bar, more preferably at most 40 bar, more preferably at most 30 bar. The operating temperature and pressure of a distillation tower is a range; and the entirety of the range preferably falls within these specified ranges. In a preferred embodiment, the cryogenic distillation has at most 80 trays, more preferably at most 60 trays, more preferably at most 50 trays, more preferably at most 40 trays, more preferably at most 30 trays, more preferably at most 20 trays, more preferably at most 15 trays, more preferably at most 10 trays, more preferably at most 9 trays, more preferably at most 8 trays, more preferably at most 7 trays, more preferably at most 6 trays, more preferably at most 5 trays, more preferably at most 4 trays, more preferably at most 3 trays, more preferably at most 2 trays, more preferably at most 1 tray. A cryogenic distillation with only 1 tray is considered a cryogenic flash herein. The applicant surprisingly found that CO2 can be extracted, and assuming no further constituents, high purity CO can be obtained with a limited number of trays. Limiting the number of trays is then advantageous to reduce both complexity of installation as well as operating energy requirements.
In a preferred embodiment, the present invention relates to a method for producing carbon monoxide (CO), comprising the steps of:
Inventors have surprisingly found the following method to be energetically highly favorable for the production of a CO-rich stream from a gaseous inlet comprising CO2. Plasma conversion allows for energetically efficient dissociation of CO2. Carbon donor particles scavenge O2 as well as oxygen radicals and promote reverse Boudouard reaction. This provides two benefits: greatly increasing the CO yield as well as removing the need for oxygen separation. CO and CO2 can then be separated to high purities. Purity of the CO-rich stream of at least 90%, up to 99% can be obtained without the need cryogenic distillation with large number of trays or subsequent purification processes. The CO2 rich stream can be trivially recycled. The CO-rich stream can advantageously be used in the reduction of iron ore.
In a preferred embodiment, the system for producing carbon monoxide further comprises:
In an embodiment, said carbon donor system is configured to produce a down flow of carbon-donor particles, preferably under the influence of gravity, while the down flow of carbon-donor particles is exposed to O radicals, preferably in counter-flow to the down flow. In a preferred embodiment, the carbon-donor particles are positioned in a fixed bed.
The plasma reactor, and preferably the one or more reactor chambers thereof, can preferably be equipped with a swappable catalyst bed tray. In tris tray, various solids and liquids can preferably be added to the process, in order to enhance the conversion. One preferred example is coal, which upon heating by the plasma will improve the CO yield by the reverse Bouduard reaction. The catalyst tray can be fixed, or on continuous supply chain, i.e. a rotating belt or a feed screw. The catalyst bed can preferably be adjustable in position, i.e. up and down, in order to provide optimal distance to the plasma afterglow. Multiple stacked trays may also be preferred. A rail insert can be provided in the plasma reactor, and preferably the one or more reactor chambers thereof, to hold the catalyst tray.
In an embodiment of the invention, the plasma reactor comprises a set of electrodes (or waveguides, coils and contacts where applicable) in and/or around the plasma zone, the electrodes configured to ignite a plasma using any or any combination of the following:
In an embodiment, the plasma reactor comprises a single reactor chamber. However, in other embodiments, the plasma reactor comprises two or more reactor chambers, each reactor chamber comprising a plasma zone. Hereby, the reactor chambers may be positioned in series and/or in parallel. The number of reactors may be any of 2, 3, 4, 5, 6, 7, 8, 9, 10 or more.
In an embodiment, the reactor chamber is made of steel, copper, aluminium, ceramics, plastic, or any combination thereof. Alternatively or additionally, the plasma reactor may be made of recycled materials.
In an embodiment, the plasma reactor comprises a DC or an AC electric power source. The power range of the plasma reactor may range between 1 and 1,000,000 kW.
In a preferred embodiment, the system for producing CO comprises multiple plasma reactors which are arranged in series and/or in parallel with respect to the initial input stream and the final output stream. Preferably, the multiple reactors are arranged in parallel. This allows upscaling of the system to large volumes of CO2 comprising streams. Hereby, the multiple plasma reactors may be arranged in a matrix form, and the initial input stream may be divided over the parallel-arranged reactors using a manifold and/or a set of division valves. Preferably the system comprises N plasma reactors, wherein N is between 2 and 10000, preferably between 10 and 5000, such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 50, 70, 100, 200, 300, 500, 700, 1000, 1500, 2000, 3000, 5000, 7000 or 10000.
Hereby, the system for producing CO may comprise a recycling system configured to receive the output streams of multiple plasma reactors and to recycle the combined output stream as an input stream for the multiple plasma reactors.
Alternatively, or additionally, the system for producing CO may comprise multiple recycling systems, each of which configured to receive the output stream of one plasma reactor or of a subset of the multiple plasma reactors and to recycle the output stream as an input stream for the one plasma reactor or the subset of the multiple plasma reactors.
In a preferred embodiment, the recycling system comprises one or more pumps and/or fans configured for pumping the output stream of a plasma reactor to an input of a different and/or the same plasma reactor. If such a pump is used, this pump may be of any suitable type, including centrifugal, rotary, positive displacement, diaphragm, gear and others.
The plasma zone (23) may preferably comprise an ignition gap, preferably a cylindrical ignition gap, between the electrodes of between 1 mm and 20 mm, preferably about 2 mm.
Preferably the plasma inlet (24) is positioned eccentric and/or tangential with respect to the reaction chamber, allowing formation of a vortex in the plasma and in the plasma afterglow.
Note that the plasma is ignited in the plasma zone, but that the conversion of the CO2 to CO may occur in the plasma zone and/or further downstream in the reaction chamber, e.g. in the plasma afterglow. Note that the plasma reactor (6) comprises a stabiliser for stabilizing a vortex (26) in the plasma and in the plasma afterglow, the stabiliser comprising a set of plasma reactor walls shaped to stabilize the vortex (26).
In an embodiment, the method for producing CO of the present invention comprises the step of separating the final output stream in two or more separated streams. Preferably hereby, the separating step comprises extraction of CO2 and/or extraction of oxygen (O2) from the final output stream. Preferably, the separating step makes use of any or any combination of:
In an embodiment, the extraction system of the system for producing carbon monoxide comprises a separator for separating the final output stream in two or more separated streams, the separator being configured to extract CO2 and/or O2 from the final output stream. Preferably, the separator comprises any or any combination of:
In a preferred embodiment, the system for producing carbon further comprises:
In a particular preferred embodiment, the system for producing carbon further comprises:
The inventors have found that this combination of features removes the need to extract O2; drastically reducing the energy requirements and complexity of separator. In a preferred embodiment, the separator is a cryogenic flash. In a further preferred embodiment,
In a particular preferred embodiment, the system for producing carbon comprises:
Preferably said separator is chosen from: cryogenic flash, cryogenic distillation or a combination thereof. More preferably said separator is a cryogenic flash. In a further preferred embodiment, said CO2-rich separator output is fluidly connected to said CO2 input system; thereby recycling said CO2-rich separator output.
In a particular preferred embodiment, the system for producing carbon comprises:
Preferably, the plasma reactor comprises one or more catalyst bed trays as previously described, whereby the trays can preferably be provided with gas separation membranes such as BSCF hollow fibers, which are used for O2 scavenging.
In an embodiment, the recycling system of the system of the present invention comprises a set of recirculation blowers and/or recirculation pumps configured to recycle the output stream as an input stream to the plasma zone.
In an embodiment, the plasma is stabilized, preferably by using any or any combination of:
Accordingly, the plasma reactor of the system according to the present invention preferably comprises plasma stabilisation means, preferably any or any combination of:
The method and system for producing CO of the present invention can preferably be used to convert CO2 in an exhaust gas of a blast furnace to CO. Preferably the blast furnace uses said CO to produce iron from iron ore. Hereby, the complete process of producing iron from iron ore can be performed with reduced CO2 exhaust to the environment, preferably even without CO2 exhaust to the environment. Reduction of iron ore to iron requires energy, and the energy required to reduce the iron ore to iron can be obtained from electrical power, which can also be obtained with reduced or even without CO2 exhaust. The energy for the iron ore to iron reduction process comes from the plasma process wherein CO2 is converted to CO at high temperature.
The system for producing CO needs to be able to pass the CO2 comprising gas multiple times through the one or more plasma reactors, in order to achieve optimal conversion. A single pass may typically convert 10-15% of the CO2 gas. Passing through (recirculating) the gas 5 times yields about 50% CO2 conversion. Flow rates may preferably be between 10 and 100 L/min per plasma reactor.
In an embodiment of the invention, the system for producing carbon monoxide comprises one or more inlet valves upstream of the plasma inlet and whereby the extraction system comprises one or more outlet valves downstream of the plasma outlet, whereby the one or more inlet valves are configured to:
This embodiment is better illustrated in
During stage 1, valve 1 (30) is open and the system fills up with initial input gas from an initial gas stream supply (34). During this first stage, 10% of the CO2 in the gas can already be converted. Once the system is filled up with gas (1 cycle), valve 1 (30) closes, valve 2 (31) closes, and the pump (32) starts working. After 4 re-cycles, the conversion of CO2 reaches about 50%, upon which valve 2 (31) opens, and subsequently the pump (32) shuts off and valve 1 (30) opens to flush the system with initial input gas again. A separation stage (33) can preferably be included in the loop and feedback of excess CO2 that is not converted may be implemented. In this way, the system will operate in a “pulsed” regime. However, due to the small internal volume of the individual plasma reactors, this process will result in a very low residence time (of the order of 100 ms). A full re-circulation sequence takes between 0.1 and 10 seconds, preferably about 0.5 s. This results in a semi-continuous operation. Furthermore, when using multiple plasma reactors, the first, second and third stages may be shifted for different plasma reactors, such that the initial input stream may continuously be divided over a subset of the plasma reactors which are at any time in the first stage.
An example of the complete cycle can be summarized in the table below:
Each step of the cycle may preferably take between 50 and 500 ms, preferably about 100 ms.
The valves may preferably be controlled with electronic actuators connected to a computer board.
Depending on the operating conditions and total reactor volume, the recirculation pump may not be able to spin up fast enough in order to match the recirculation timing. In an embodiment, the recycling system, and preferably one or more pumps thereof, is configured to operate continuously, at full or reduced power, i.e. without startup-cycles. Instead of stopping the pumps, the one or more pumps are configured to operate in open air, and are configured to recycle an output gas stream by using a set of valves when required, e.g. in the recirculation stage, i.e. stage 2 in the embodiment presented above. See
In embodiments, recycling may be obtained by pressure forces, pressure gradients and/or buoyance forces. In such embodiments, the recycling system may not comprise a pump. In embodiments, the valves described in 3, 4 and 5 may be fully open at all times. In such configurations, the gas flow may recirculate naturally, driven by pressure and buoyance forces.
In embodiments, re-circulation of an output stream as an input stream may be realized by by-pass piping and/or pumps, but may also be realized without by-pass piping and/or pumps. A passive system may preferably utilize an internal flap or a duct, re-directing the output stream partially, or completely back to the inlet of the reactor. Alternatively, or additionally, in an active system, a moving flap or a propeller may be installed, facilitating re-directing the output stream partially, or completely back to the inlet of the reactor. In certain embodiment, natural internal re-circulation of the gas in the reactor may occur. One preferred embodiment is to use a classical gliding arc suspended in an enclosed vessel of any given shape. Preferably, hereby, utilizing a central axial flow and an off-center outlet may facilitate internal recirculation. Additionally, internal recirculation is possible in vortex and reverse-vortex flow reactors.
In an embodiment, rotating, vibrating or displacing the plasma reactor, or at least a portion thereof, preferably a portion comprising the plasma zone, may be utilized to obtain recycling of the output stream as an input stream.
Note that in an embodiment, the system comprises any or any combination of the following:
In an embodiment, the plasma reactor can be devised in a tubular shape, but may also be devised in a rectangular, conical, planar or spherical shapes, and/or any combination thereof and of a tubular shape.
In the present invention, preferably at least 50% of the CO2 in the initial gaseous input stream is converted to CO. This means that a portion of the CO2 in the initial input stream may still be present in the final output stream. Therefore, preferably the method of the present invention comprises the step of separating CO2 from the output stream and/or the final output stream. Preferably, the separated CO2 is fed back into the plasma reactor as an initial input stream. This creates a secondary CO2 stream, in addition to the main input, e.g. coming directly from a blast furnace. Preferably, therefor, the system comprises an input mixer and/or a buffer stage configured to mix and/or store the main CO2 input stream and/or the secondary CO2 input stream. The buffer may comprise an expansion chamber and/or a gas delivery pipe capable of withstanding high pressure. The buffer (50) is illustrated in
In an embodiment of the iron production method and system of the invention, the plasma reactor may be attached directly to the blast furnace body. In other embodiments, the initial input stream comprising CO2 is transported to the plasma reactor by pipes or by pressurised containers. In an embodiment of the invention, the exhaust gas of the blast furnace may be liquefied and transported to the plasma reactor. Hereby the liquefied exhaust gas may preferably be evaporated in order to be used as initial input stream.
In an embodiment, co-reactants are added to the input stream in the reaction chamber. Preferably the co-reactants comprise any or any mixture of: water vapour, carbon and/or sulphur.
In an embodiment, the initial input stream comprises essentially pure CO2 gas, e.g. comprising at least 98 vol. % of CO2. In other embodiments, the initial input stream is a mixture of components, said mixture comprising CO2 and any or any combination of CO, hydrogen (H2), nitrogen (N2), oxygen (O2), Argon (Ar), methane (CH4), and/or water (H2O).
In an embodiment, the plasma reactor is configured to operate at a range of gas flow rates between 1 to 10,000,000 L/min.
In an embodiment, the plasma reactors are configured to operate at a pressure in the range of 1 atm to 100 atm.
In a preferred embodiment, recycling the output stream as an input stream comprises the step of cooling down the output stream, preferably by:
In a preferred embodiment, the second aspect of the invention relates to an iron production method comprising the steps of:
The invention also relates to an iron production system comprising:
This method and system have several major advantages:
The separation of a series of CO2/CO/O2 mixtures was modelled. The CO to O2 ratio was modelled starting from CO2 dissociation. 2 CO2 is thus converted to 2 CO and 1 O2 molecules. The ratio of CO2 to CO and O2 is determined by the single pass conversion of the plasma reactor. The selection criterium was a CO-rich stream with at least 99 wt. % CO and max. 0.2 wt. % O2. Oxygen is not desired for downstream use of the CO rich stream in blast furnace applications.
The applicant modelled a range of cryogenic flash setups over the full range of CO2/CO/O2 mixtures. The applicant did not find a single cryogenic flash able to meet these criteria. The CO-content in the CO-rich stream was limited due to the inability to effectively separate both O2 and CO2 from CO. Additional separation stages were required to obtain a CO-rich stream according to the spec of 99 wt. % CO; leading to increased energy requirements and additional complexity.
Cryogenic distillation of a series of CO2/CO/O2 mixtures was modelled. The distillation column is designed to have a distillate temperature of −142° C. and a bottom temperature of −132° C. The operating pressure is 26 bar and the column consists of 60 stages. Table 1 shows the results from this method at a feed rate of 10000 tonnes/year. We can see that the desired CO concentration between 99-100% is only reached at 10, 20 and 100% CO2 conversion. It is clear that 100% CO2 conversion is currently not yet achievable. Conversion of 10 and 20% is achievable but higher conversion is clearly desired. It is furthermore noted that while high purity CO stream is obtained, the mass flow rate of this stream remains low. Reducing the purity of CO results in the oxygen content exceeding the 0.2% maximum.
Examples 1 and 2 show the difficulty in separating the output of a CO2 dissociation process, i.e. a gas comprising CO2, CO and O2.
A fixed carbon particle bed was added downstream of the plasma reactor. The applicant found the addition of this carbon particle bed eliminated the oxygen content from the resulting gas stream almost completely (down to ppm range).
The location of the carbon particle bed was varied between very close to the plasma reaction zone, in the plasma afterglow region and a substantial distance between plasma reactor and carbon particle bed. In both cases, oxygen was almost fully eliminated. However, the CO to CO2 ratio varied. Higher CO content was found when the carbon particle bed was placed in the plasma afterglow zone.
Without being bound to theory, it is assumed that O2 and/or oxygen radicals quickly react with available carbon particles. Removal of O2 and oxygen radicals limits the combination with available CO to form CO2. Furthermore, available CO2 may react with carbon particles to form CO through the reverse Boudouard reaction, promoted at higher temperatures. It was thus found that the addition of a carbon donor increases CO yields; which may further be impacted by the location of said carbon particles.
Separation of CO2/CO gas streams was investigated over a wide range of CO2 to CO ratios. The applicant found that a cryogenic flash operated at −140° C. and at a pressure of 26 bar resulted in a 99.8% pure CO top stream for mixtures between 10 and 90% CO2 for all feed rates. Table 2 shows the results that belong to the feed stream of 10,000 tonnes/year. Furthermore, high mass flow rates were obtained.
This shows that the CO and CO2 streams may be separated and recycled to blast furnace and plasma reactor respectively for a wide range of (single pass) plasma reactor conversion rates.
Pressure swing absorption of a series of CO2/CO/O2 mixtures was modelled, similar to those discussed in examples 1 and 2. Pressure swing absorption did not result in any streams with a CO purity of at least 90%.
Pressure swing absorption of a series of CO2/CO mixtures was modelled, similar to those discussed in examples 4. A result of 98.09% CO was achieved only with a 10% CO2/90% CO mixture. PSA thus only achieved high purity CO if very high reactor conversion can be obtained, even with the addition of a carbon donor.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21197851.5 | Sep 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/076110 | 9/20/2022 | WO |
