FR3120654A1 - Replaceable on-board carbon dioxide capture system for internal combustion engine - Google Patents

Abstract

Replaceable on-board carbon dioxide capture system for internal combustion engine Replaceable on-board CO2 capture system (1) for internal combustion engine to reduce the amount of CO2 released into the atmosphere by the internal combustion engine, the system comprising: a main exhaust gas path (17) configured to vent the exhaust gas stream (2) to the atmosphere without further treatment for CO2 capture; a secondary exhaust gas path (18) configured to direct the flow of exhaust gases (2) through a CO2 capture zone (19); the CO2 capture zone (19) comprising a container (5) containing a CO2 capture material; a first CO2 level sensor (4) at the inlet of the secondary exhaust gas path (18) for determining the CO2 content of the exhaust gas stream (2) leaving the internal combustion engine; a second CO2 level sensor (21) at the outlet of the secondary exhaust gas path (18) for determining the CO2 content of the exhaust gas flow (2) leaving the CO2 capture zone ( 19); distribution means (10) disposed at the inlet of the secondary exhaust gas path (18) to direct the flow of exhaust gases (2) to the CO2 capture zone (19); wherein the main exhaust gas path (17) is configured to guide said exhaust gas flow (2) when the CO2 content as determined by said first CO2 level sensor (4) is below a predetermined value; the secondary exhaust gas path (18) is configured to guide said exhaust gas flow (2) when the CO2 content as determined by said first CO2 level sensor (4) is above a predetermined value ; said container (5) comprises at least two reactors, a reactor in use (8) and a reserve reactor (20); the CO2 capture material is an alkali metal oxide; the CO2 capture zone (19) is configured to manually replace the saturated in-use reactor (8), as detected by said second CO2 level sensor (21), with the standby reactor (20 ); the saturated reactor in use (8) is configured such that after being replaced by said reserve reactor (20), it is emptied and then filled with a new charge of CO2 capture material. Figure for the abstract: [Fig. 1]

Description

Replaceable on-board carbon dioxide capture system for internal combustion engine

Technical field of the invention

The present invention relates to the field of automotive technology and more specifically to the field of carbon dioxide removal (CO₂) of the flow of exhaust gases from an internal combustion engine used to propel a motor vehicle. In particular, the invention relates to a system for capturing CO₂replaceable board. Furthermore, the invention relates to a method for eliminating the CO₂of the exhaust gas flow of an internal combustion engine using the capture system CO₂replaceable vehicle, and a vehicle using such a system.

State of the art

When internal combustion engines are operated, exhaust gases are generated which are contaminated with pollutants such as carbon dioxide. Since these pollutants are harmful to the environment, stricter limit values are continually being set for the concentration of these pollutants in the exhaust gases of internal combustion engines. Previous methods for treating exhaust gases to reduce the concentration of pollutants emitted by an internal combustion engine are based on oxidation or reduction of pollutants by means of catalysts. These conventional methods are no longer sufficient to meet the new regulations.

European Regulation 2019/631 sets _CO2 emission performance requirements for cars, which are very difficult to meet. From ¹ January 2020, the regulation sets an EU-wide fleet target of 95 g/km _CO2 for the average emissions of new passenger cars registered in the Union. If this limit is exceeded, penalties will be paid by the manufacturers. The cost of technologies to reduce CO ₂ emissions varies between 10 €/g of CO ₂ and 200 €/g of CO ₂ (PHEV). CO ₂ emissions are directly linked to fuel consumption and, in the absence of additional systems, such as hybridization, the objective is largely exceeded.

Document EP 3 523 516 discloses a method for purifying exhaust gases generated by an internal combustion engine. The exhaust gases generated by the internal combustion engine are conducted through an exhaust gas circuit which is equipped with at least one adsorption element to which the pollutants contained in the exhaust gases bind at least partially. The at least one adsorption element is regenerated by the at least partial desorption of the bound pollutants, and the pollutants desorbed from the at least one adsorption element during the desorption process are stored in at least one storage unit.

The technical solution disclosed by document EP 3 523 516 is a double exhaust line at the engine outlet, each line comprising a CO ₂ capture system. In this document, all of the gases pass through one or the other of the lines, depending on the capture system which is active, the other system being able to be regenerated by heating (for example it is possible to regenerate when not driving). The gases necessarily pass through a capture system. With this system, we must achieve a much more radical CO ₂ purification, but this is at the cost of a greater frequency of regeneration and therefore fuel consumption because of the electric heating.

The object of the present invention is to eliminate the defects of the existing solutions of the state of the art, that is to say to effectively purify the CO ₂ without having the problem of fuel consumption thereof.

In this context, the present invention proposes a simple on-board technical solution for capturing and storing the CO₂in a reactor, similar to a replaceable filter. The system is designed to also provide a direct display of emissions rates and on-demand optimization of engine operating speed to reduce CO emissions.₂.

Presentation of the invention

The invention aims to remedy the shortcomings of known CO ₂ capture systems and methods, by proposing a system and a method for capturing CO ₂ contained in the exhaust gases of an internal combustion engine which is intended to propel a motor vehicle, without regeneration of the CO ₂ capture equipment and therefore having low system consumption and reduced costs.

The invention accomplishes this by providing a replaceable on-board CO ₂ capture system for internal combustion engine emissions to reduce the amount of CO ₂ from exhaust gases that is released to the atmosphere. Contrary to the technical solution of the documents of the state of the art, the solution of the present invention will not have a high fuel consumption because it does not foresee a regeneration of the CO ₂ capture material; the CO ₂ capture zone is configured so as to manually replace the reactor in use detected in the saturated state by a CO ₂ level detector with a reserve reactor; in addition, the saturated reactor is configured so that after being replaced by a reserve reactor, it is emptied and then filled with a new charge of CO ₂ capture material. Thus, the technical solution of the present invention should therefore allow a “just necessary” purification of the standard, which allows significant fuel savings.

According to a first aspect, the invention provides a system for capturing CO₂replaceable on-board for internal combustion engine to reduce the amount of CO₂vented from the internal combustion engine to the atmosphere, the system comprising a main exhaust gas path configured to vent the exhaust gas stream to the atmosphere without any further processing for the capture of the CO₂; a secondary exhaust path configured to direct the flow of exhaust gas through a capture zone of the CO₂comprising: a container containing a CO capture material₂; a first CO level detector₂at the inlet of the secondary exhaust path to determine the CO content₂the flow of exhaust gases leaving the internal combustion engine; a second CO level detector₂at the outlet of the secondary exhaust path to determine the CO content₂the flow of exhaust gases leaving the capture zone of the CO_2;distribution means disposed at the inlet of the secondary exhaust gas path to direct the flow of exhaust gases towards the zone for capturing the CO_2;characterized in that: the main exhaust gas path is configured to guide said exhaust gas flow when the CO content₂as detected by said first CO level detector₂is less than a predetermined value; the secondary exhaust gas path is configured to guide said exhaust gas flow when the CO content₂as detected by said first CO level detector₂is greater than a predetermined value; said container comprises at least two reactors, a reactor in use and a reserve reactor; CO capture material₂is an alkali metal oxide; CO capture zone₂is configured so as to manually replace the reactor in use, detected in the saturated state, by said second level detector of CO₂by the reserve reactor; the saturated reactor is configured in such a way that after being replaced by said reserve reactor, it is emptied and then filled with a new charge of capture material from the CO₂.

The advantages of using the capture system CO₂replaceable embedded for the emissions of the internal combustion engines of the present invention are as follows: the cost of this technology is very low and the system is simple compared to the technologies already applied such as electrification, hybridization etc.; The by-product of the CO capture system₂On board replaceable according to the invention, calcium oxide, CaO, is a very cheap product, so that the reactors can be manufactured and sold at very low prices. In addition, the product "laden" with CO₂, calcium carbonate, CaCO₃, will be used in agriculture, zootechnics and industry. It is not recommended to decarbonize CaCO₃to obtain CaO, because CO₂will be generated, and the absorption efficiency decreases with the number of decarbonizations (according to published papers).

In a second aspect, the invention proposes a replaceable on-board CO ₂ capture system for an internal combustion engine in which the alkali metal oxide is CaO.

In a third aspect, the invention provides a CO capture system₂replaceable on-board for internal combustion engine in which the reaction inside the reactor in use contained in the capture area of the CO₂is the carbonation.

In a fourth aspect, the invention provides a replaceable on-board CO ₂ capture system for an internal combustion engine, wherein the CO ₂ capture material is in powder form.

In a fifth aspect, the invention provides a replaceable on-board CO ₂ capture system for an internal combustion engine, in which the reactor in use and the reserve reactor can be made in the form of replaceable cartridges.

In a sixth aspect, the invention provides a replaceable on-board CO ₂ capture system for an internal combustion engine, wherein the system is mounted on a mobile vehicle.

In a seventh aspect, the invention provides a system for capturing CO₂replaceable on-board for internal combustion engine, wherein the moving vehicle is a motor vehicle, van, truck.

In an eighth aspect, the invention provides a system for capturing CO₂replaceable on-board for internal combustion engine in which the predetermined value of the amount of CO₂in the exhaust gas stream is stored in the memory of a supervisor of CO_2.

In a ninth aspect, the invention provides a method for reducing the amount of CO₂from the flow of exhaust gases from an internal combustion engine, the method being characterized by comprising:

-a step during which the exhaust gas flow is directed through the secondary exhaust gas path when the CO content₂as determined by the first level detector of CO₂at the entrance to the secondary exhaust gas path is greater than a predetermined value;

-a step during which the flow of exhaust gases is passed through a zone for capturing the CO₂included in the secondary exhaust gas path;

-a step during which the flow of exhaust gases is brought into contact with a CO ₂ capture material contained in a reactor in use in the CO ₂ capture zone to extract the CO ₂ from the flow exhaust gases;

-a stage during which the reactor in use is replaced by the reserve reactor when the equipment for capturing the CO₂is saturated with CO₂;

-a step during which the capture material is removed from the CO₂saturated from the saturated reactor;

-a step during which the empty reactor is filled with a new charge of material for capturing the CO_2;

-a step during which the flow of the exhaust gases is directed via the main route of the exhaust gases when the CO content₂as determined by the first level detector of CO₂at the entrance to the secondary exhaust gas path is less than a predetermined value and it is discharged into the atmosphere without any further treatment for the capture of the CO₂.

In a tenth aspect, the invention provides a CO capture system₂replaceable on-board for internal combustion engine that can be mounted in large mobile installations, such as 20-30 ton large trucks that can drive or park in cities and absorb the CO_2,in which the air circulation in the reactors is ensured by large fans.

The novelty of the present invention compared to other known solutions is the architecture of the CO storage system₂, a reactor with the absorbent, with the possibility of replacing it when it is saturated. The system is designed as a replaceable filter. Another difference compared to other known solutions is that it is possible to automatically optimize the engine operating speed to respect the CO limit.₂. In addition, the system is very simple, it ensures the capture of CO₂by a product, such as calcium oxide (CaO) which by absorption of CO₂turns into calcium carbonate (CaCO₃) which will be used for industrial, agricultural etc. Many CO capture solutions₂applied in industry are known. Some patents present complicated, in-vehicle solutions to capture CO_2,but with a CO storage system₂under pressure, expensive and energy-intensive.

Presentation of figures

Now, a preferred embodiment of the invention will be described in connection with the accompanying drawings in which:

There is a schematic representation of a replaceable on-board CO2 capture system for an internal combustion engine according to the invention;

There is a chart showing the components of internal combustion engine exhaust.

detailed description

The invention will be better understood on reading the following description of a non-limiting embodiment of the invention.

To capture the CO₂, we use the chemical reaction between the CO₂and an absorbent. An example of such a chemical reaction is carbonation

[Math. 1] CO ₂ + CaO = CaCO ₃ ,

in a replaceable reactor. The flow of engine emissions is distributed, after the catalyst, by a distribution means 10, controlled by a supervisor of CO₂13, which can direct the emission stream to the reactor in use 8 if the emission rate of CO₂is higher than a programmed limit (for example 95 gr/km CO₂), or to squelch 11 if the rate is below the limit. The CO supervisor₂comes in the form of an electronic computer connected to a certain number of sensors (CO detectors₂) and actuators (means of distribution). The rate of CO₂is measured using level detectors CO₂. A first level detector CO₂4, is placed before the distribution means 10 to direct the flow towards the reactor when the limit is exceeded and a second level detector of CO₂21, at the outlet of the reactor in use 8 to detect the saturation of the reactor.

An alert will be displayed on the dashboard of the vehicle 16 when the level of CO₂at the exit of the reactor in use 8 is close to the limit to change reactor. The saturated reactor will be replaced manually by a reserve reactor 20 and the saturated reactor will be recovered manually. The emission stream at the reactor outlet will reconnect with the exhaust before the muffler. Reactor in use 8, working in container 5; the container is equipped with a heating system, in particular an electrical resistance 6, for additional heating of the reactor in order to ensure the optimum reaction temperature.

For manual replacement of the saturated in-use reactor 8, a hatch may be provided on the side of the upper part of the vehicle body. The driver recovers the saturated reactor, changes the saturated reactor with the reserve reactor 20, discards the saturated CO ₂ capture material and fills the empty reactor with a new charge of CO ₂ capture material.

A system for measuring and controlling the temperature of the reactor 7 is provided. Control of the CO ₂ system is carried out by the CO ₂ supervisor 13 connected to all the elements of the CO ₂ system and also to the engine computer 14. The modes of operation can be selected by the controls 15. The composition average emissions from combustion engines is in accordance with the table in the . The kinetics of the carbonation reaction is as follows:

[Math. 2] CaO+ CO₂→ CaCO₃

[Math. 3] CaO+ CO₂+ H₂O → Ca(OH)₂+ CO₂→ CaCO₃+ H₂O

The optimum temperature for the capture of CO₂is of the order of 400-450°C. As the temperature of the emissions at the outlet of the catalyst is of this order of magnitude, the heating of the reactor is ensured by the thermal energy of the emissions; in the engine start-up phase, an electric reactor heating system will be used. The calculation of the feasibility of this technology is as follows:

-One mole of CaO (40+16)=56g

-A mole of CO₂(12+2*16)=44g

-One mole of CaCO ₃ (40+12+3*16)=100g;

It is considered that a 10 kg reactor is easy to replace manually, so that 4.4 kg of CO₂can be captured theoretically with 5.6 kg of CaO. Published studies show good reaction efficiency, particularly for the first absorption cycle. If, for example, we propose to reduce on average 10g of CO₂/km/vehicle, we need to capture 10*100/1000=1kg of CO₂for every 100 km of driving; the reactor must be changed after 440 km.

The operating modes of the replaceable on-board CO ₂ capture system according to the invention are as follows:

-Automatic: the system uses the reactor in use to reduce emissions of CO₂. The control is ensured by the supervisor of CO₂13. The level of CO emissions₂is displayed at the engine outlet and at the reactor outlet. Regardless of engine speed, if the level of CO emissions₂is greater than the predetermined value, the flow of exhaust gas 2 is diverted to the secondary exhaust gas path 18 and through the reactor in use 8. At very high engine speeds, it is possible that the level of CO emissions₂cannot be reduced below the predetermined value, even when passing through the reactor in use 8.

-Manual environmental mode: the level of CO₂is measured using the first CO level detector₂4 and CO emissions₂instantaneous and averages are displayed in the dashboard 16 compared to the maximum limit. An alert can be triggered when the limit is exceeded. Environmentally conscious drivers can adapt their driving style to ensure that the limit is not exceeded.

-Automatic ecological mode: The first level detector of CO₂4 is connected to an engine computer 14 via the CO2 supervisor 13 allowing optimization of the engine operating speed to ensure compliance with the emissions limit. At the same time, broadcasts are also displayed.

-Mode for recording broadcasts of CO₂; the quantity of CO₂released into the atmosphere in correlation with the distance will be recorded in a control computer of the car in ROM format (not modifiable) and will be searchable and transferable to the manufacturer and by the manufacturer to the authorities via the connectivity of the car or via a cable of diagnosis. This mode will make it possible to prove that the engine complied with the regulations in force.

Each "ecological" mode is automatically accompanied by the capture of the CO₂in the reactor in use 8 if the limit is exceeded.

As shown in , the flow of exhaust gases 2 from the internal combustion engine enters a conventional catalyst 3, for example a three-way catalyst in the case of a gasoline engine, which eliminates some of the pollutants but not the CO2. After leaving the catalyst 3, the flow of exhaust gases 2 encounters the first CO2 level detector 4 placed before the distribution means 10. The first CO2 level detector 4 determines the quantity of CO2 in the flow of gases exhaust and when the quantity of CO2 is greater than a predetermined value stored in a memory of the CO2 supervisor 13 (for example 95 gr/km of CO2), the CO2 supervisor 13 commands the distribution means 10 to direct the flow exhaust gas path 2 to the secondary exhaust gas path 18.

Passing through the secondary exhaust gas path 18, the flow of exhaust gases 2 passes through an interchangeable reactor unit 9. This interchangeable reactor unit 9 comprises a container 5 comprising a reactor in use 8 and at the least one reserve reactor 20. The reactor in use 8 and the reserve reactor 20 contain a quantity of capture material of the CO₂which is an alkali metal oxide. The in-use reactor 8 and the standby reactor 20 are designed to be interchangeable. When the reactor in use 8 is saturated with CO₂, it can be replaced by the reserve reactor 20 of the interchangeable reactor unit 9 in order to continue to absorb the CO₂of the flow of exhaust gases 2 without interruption. The reactor in use 8 and the reserve reactor 20 can be designed as replaceable cartridges.

The alkali metal oxide used as the capture material CO₂is in particular CaO. The current inventor has found that CaO in powder form is the best CO capture material₂. As mentioned above, the optimum temperature for the capture of CO₂is of the order of 400-450°C. As the temperature of the emissions at the outlet of the catalyst is around this value, the heating of the reactor is ensured by the thermal energy of the emissions. In the start-up phase of the internal combustion engine, when the temperature of the flow of exhaust gases 2 is still low, the necessary heat will be supplied by a heating element 6 which is in particular an electrical element which will heat the reactor during use 8.

In order to save electrical energy from the battery of the motor vehicle, the electrical element will only be energized when the temperature of the exhaust gas stream 2 is lower than about 400-450°C. This is why the interchangeable reactor unit 9 is provided with a temperature sensor for measuring the temperature of the exhaust gas stream 2 which is connected to the CO ₂ supervisor 13. When the temperature detected by the temperature sensor 6 is lower than approximately 400-450°C, the CO ₂ supervisor 13 turns on the heating element 6. When the temperature of the exhaust gas stream 2 is higher than approximately 400-450°C, the CO ₂ 13 turns off the heating element 6.

After passing through the interchangeable reactor unit 9 and thus through the reactor in use 8, the exhaust gas stream 2, which now contains less CO₂before it enters the secondary exhaust gas path 18, is directed through the exhaust 10 and into the main exhaust gas path 17 and towards the silencer 11.

Immediately after the point of intersection of the main exhaust gas path 17 and the secondary exhaust gas path 18, a second level detector CO₂21 is planned. The second level detector of CO₂21 measures the amount of CO₂in the exhaust gas stream 2 after passing through the interchangeable reactor unit 9 to determine whether the in-use reactor 8 is saturated or not. If the first level detector of CO₂4 detects that the value of the CO₂in exhaust stream 2 is less than the predetermined limit stored in the memory of the CO supervisor₂13, the distribution means 10 will not divert the exhaust gas flow 2 through the secondary exhaust gas path 18, and the exhaust gas flow 2 will pass through the main exhaust gas path 17 until to the muffler 11 and the exhaust outlet 12. In this case, the reactor in use 8 will not be used and therefore the CO supervisor₂13 will determine that reactor in use 8 is not saturated.

If the first level detector of CO₂4 detects that the value of the CO₂in exhaust stream 2 is greater than the predetermined limit stored in the memory of the CO supervisor₂13, the distribution means 10 will divert the flow of the exhaust gases 2 through the secondary exhaust gas path 18, and the capture material of the CO₂will capture the CO₂. After some time of operation, the capture material of the CO₂will be saturated. If the second level detector of CO₂21 detects that the amount of CO₂in the exhaust gas stream 2 does not decrease after a predetermined period of time, the CO supervisor₂13 determines that the reactor in use 8 is saturated and an alert message will be displayed in the dashboard regarding the situation and that it is time to change the reactors.

The replacement of the reactor in use 8 by the reserve reactor 20 is carried out manually. Once the reactor in use 8 is saturated and replaced by the reserve reactor 20 which then becomes the reactor in use 8, the saturated reactor can be emptied of the capture material of the CO₂which is no longer CaO but CaCO₃due to the carbonation reaction. The saturated reactor can be emptied into specially designed spaces at gas stations where it can be recovered and used for multiple industrial uses.

Calcium carbonate is mainly used in the construction industry, either as a building material, or as a limestone aggregate for road construction, or as an ingredient in the manufacture of cement, or as a raw material for the preparation of lime for construction by combustion in a furnace. Calcium carbonate is also suitable for a wide variety of agricultural applications including pH control, fertilizers, and animal feed formulations. Landscaping and recreation uses include decorative stone for landscaping, golf course applications and line marking of athletic fields. Instead of emptying the saturated reactor in places specially designed for this purpose, the CaCO ₃ could be dumped on the side of the road, since it is not harmful to the environment and, as mentioned above, it could be used in agriculture as fertilizer.

The Saturated Reactor that was emptied must now be refilled with a fresh charge of CO Capture Material₂in order to be ready to replace the reactor in use 8 when the CO supervisor₂13 will determine, based on the information from the second level detector of CO₂21, that the reactor in use 8 is saturated and must be replaced.

Whether the flow of exhaust gases 2 is directed through the main exhaust gas path 17 or through the secondary exhaust gas path 18, it will ultimately be directed to the silencer 11 and then to the outside atmosphere through the outlet. exhaust gases.

The invention also relates to a method for reducing the amount of CO₂from the flow of exhaust gases from an internal combustion engine using the capture system CO₂replaceable vehicle 1 of the present invention. The method consists of directing the flow of exhaust gases 2 from an internal combustion engine used to propel a motor vehicle, towards a secondary exhaust gas path 18 when the CO content₂as determined by the first level detector of CO₂4 disposed before the entrance to the secondary exhaust gas path 18 is greater than a predetermined amount. To direct the flow of exhaust gas 2 to the secondary exhaust gas path 18, a distribution means 10 is provided. In a preferred embodiment, the dispensing means 10 is a valve. The flow of exhaust gases 2 passing through the secondary exhaust gas path 18 will encounter a zone for capturing the CO₂19 comprising an interchangeable reactor unit 9. This interchangeable reactor unit 9 comprises a reactor in use 8 and at least one reserve reactor 20. The reactor in use 8 and the reserve reactor 20 contain a material capture of CO₂which is in particular CaO. Through the carbonation reaction, the carbon capture material CO₂will capture the CO₂exhaust gas flow 2 and exhaust gas flow 2, now with a lower content of CO₂, will be returned to the main exhaust gas path 17 and to the outside atmosphere.

When reactor in use 8 becomes saturated, as determined by the CO supervisor₂13 based on information from second CO level sensor₂21 arranged at the outlet of the secondary exhaust gas path 18, an alert will be displayed on the dashboard of the motor vehicle and the reactor in use 8 will be manually replaced by the reserve reactor 20. The product of the carbonation reaction which is CaCO₃could be unloaded in places specially provided for this purpose in service stations for example, or even on the side of the road, because the CaCO₃also has some agricultural uses as a fertilizer. The empty reactor must be filled with the capture material of the CO₂in order to be ready to replace the reactor in use 8 again if necessary.

If the CO supervisor₂13 determines, on the basis of the information of the first level detector of CO₂4 arranged before the entrance to the secondary exhaust gas path 18, that the quantity of CO₂in the exhaust gas stream 2 is less than a predetermined value stored in the memory of the CO supervisor₂13, the distribution means 10 will direct the flow of exhaust gas 2 to the main exhaust gas path 17 and through the silencer 11 into the atmosphere, without further treatment to capture the CO₂.

In another embodiment of the replaceable on-board CO ₂ capture system 1 of the invention, the interchangeable reactor unit 9 could accommodate more than two reserve reactors 20.

The technology of the present invention can be easily developed for stationary applications, installed in areas with high pollution to the CO₂, such as the crossroads of large cities for example. Similarly, it is possible to develop large mobile plants of 20 to 30 tons, installed in large trucks that can travel or park in cities and absorb the CO₂. In addition to the presented system, the CO absorption plants₂for ambient air must be equipped with fans to ensure the forced circulation of air through the reactors.

The invention is useful in the automotive industry as a replaceable on-board system for reducing the CO ₂ content of the exhaust gas stream of an internal combustion engine used to propel a mobile vehicle.

Claims (10)

CO capture system₂(1) On-board replaceable for internal combustion engine to reduce the amount of CO₂released to the atmosphere by the internal combustion engine, the system comprising:
- a main exhaust gas path (17) configured to discharge the exhaust gas stream (2) to the atmosphere without further treatment for CO capture₂;
- a secondary exhaust gas path (18) configured to direct the flow of exhaust gases (2) through a CO capture zone₂(19);
- the CO capture zone₂(19) comprising a container (5) containing a CO capture material₂;
-a first CO level detector₂(4) at the entrance to the secondary exhaust path (18) to determine the CO content₂the flow of exhaust gases (2) leaving the internal combustion engine;
-a second CO level detector₂(21) at the outlet of the secondary exhaust gas path (18) to determine the CO content₂of the exhaust gas flow (2) leaving the CO capture zone₂(19);
- a distribution means (10) arranged at the inlet of the secondary exhaust gas path (18) to direct the flow of exhaust gases (2) towards the CO capture zone₂(19);
characterized in that
- the main exhaust gas path (17) is configured to guide said exhaust gas flow (2) when the CO content₂as determined by said first CO level sensor₂(4) is less than a predetermined value;
- the secondary exhaust gas path (18) is configured to guide said flow of exhaust gases (2) when the CO content₂as determined by said first CO level sensor₂(4) is greater than a predetermined value;
- said container (5) comprises at least two reactors, a reactor in use (8) and a reserve reactor (20);
-the CO capture material₂is an alkali metal oxide;
- the CO capture zone₂(19) is configured to manually override the saturated in-use reactor (8), as detected by said second CO level sensor₂(21), by the reserve reactor (20);
-the saturated reactor in use (8) is configured such that after being replaced by said reserve reactor (20), it is emptied and then filled with a new charge of CO capture material₂. The replaceable on-board CO ₂ capture system (1) for an internal combustion engine according to claim 1, characterized in that the alkali metal oxide is CaO. The replaceable on-board CO ₂ capture system (1) for an internal combustion engine according to claims 1 to 2, characterized in that the reaction in the in-use reactor (8) contained in said CO ₂ capture zone (19) is carbonation. The CO capture system₂(1) replaceable on-board for internal combustion engine according to claims 1 to 3,characterized in thatthe capture material of the CO₂is in powder form. The capture system CO₂(1) replaceable onboard internal combustion engine according to claims 1 to 4characterized in thatthe reactor in use (8) and the reserve reactor (20) can be made in the form of replaceable cartridges. The replaceable on-board CO ₂ capture system (1) for an internal combustion engine according to claims 1 to 5 characterized in that the system is mounted on a mobile vehicle. The replaceable on-board CO ₂ capture system (1) for internal combustion engine according to claims 1 to 6 characterized in that the mobile vehicle is a motor vehicle, a van, a truck. The CO capture system₂(1) replaceable onboard internal combustion engine according to claims 1 to 7,characterized in thatthe predetermined value of the quantity of CO₂in said exhaust gas flow (2) is stored in the memory of a supervisor of CO₂(13). Method to reduce the amount of CO₂from the flow of exhaust gases (2) from an internal combustion engine, the method being characterized in that it comprises:
-a step during which the flow of exhaust gas (2) is directed through the secondary exhaust gas path (18) when the CO content₂as determined by the first level detector of CO₂(4) at the entrance to the secondary exhaust gas path (18) is greater than a predetermined value;
-a step during which the flow of exhaust gases (2) is passed through a CO capture zone₂(19) included in the secondary exhaust gas path (18);
-a step during which the flow of exhaust gases (2) is brought into contact with a CO capture material₂contained in a reactor in use (8) in the CO capture zone₂(19) to extract CO₂the exhaust gas flow (2);
-a step during which the reactor in use (8) is replaced by the reserve reactor (20) when the CO capture equipment₂is saturated with CO₂;
-a step during which the CO capture material is removed₂saturated from the saturated reactor;
-a step during which the empty reactor is filled with a new charge of CO capture material₂; And
-a step during which the flow of exhaust gases (2) is directed via the main exhaust gas path (17) when the CO content₂as determined by the first CO level sensor₂(4) at the inlet of the secondary exhaust gas path (18) is less than a predetermined value and it is discharged into the atmosphere without any further treatment for the capture of CO₂. The CO capture system₂(1) replaceable on-board for internal combustion engine according to claims 1 to 8,characterized in thatthe system can be mounted in large mobile installations, such as large 20-30 ton trucks that can drive or park in cities and absorb the CO_2,in which the air circulation in the reactors is ensured by large fans.