VEHICULAR EMISSION

FIELD OF I VENTION

The invention relates to the field of pollution control of vehicle exhausts. More particularly, the invention relates to method or system to separate or remove carbon dioxide from vehicle exhausts. More particularly, the invention relates to a system using a carbon dioxide absorbent to capture or extract the carbon dioxide gas and then removing the absorbed carbon dioxide.

BACKGROUND OF THE INVENTION:

Most internal combustion engines emit carbon dioxide (CO ₂ ) as a by-product of an internal combustion process. Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline, petrol, biodiesel blends, diesel fuel, fuel oil, or coal. According to the type of engine, it is discharged into the atmosphere through an exhaust pipe, flue gas stack, or propelling nozzle. It often disperses downwind in a pattern called an exhaust plume. There is a need for reducing emissions of CO ₂ , in particular, vehicle related C0 ₂ emissions as motor vehicle emissions contribute to air pollution and are a major ingredient in the creation of smog in some large cities. The largest proportion of most combustion gases is nitrogen N ₂ , water vapour, and carbon dioxide, C0 ₂ of which carbon dioxide is a greenhouse gas that contributes to global warming. While there are methods to remove carbon dioxide from other emissions, there are not many known methods to remove C0 ₂ from vehicle exhausts and there is need for new and efficient methods to do so. The term "scrubber" is usually referred to pollution control devices that use liquid to wash unwanted pollutants from a gas stream. It also describes systems that inject a dry reagent or slurry into a dirty exhaust stream to "wash out" acid gases. Scrubbers are one of the primary devices that control gaseous emissions, especially acid gases. Scrubber systems are a diverse group of air pollution control devices that are used to remove some particulates and/or gases from industrial exhaust streams for example the scrubber to remove carbon dioxide from the air of submarines. Scrubbers can also be used for heat recovery from hot gases by flue-gas condensation.

The scrubbing systems can be wet or dry based on the manner they treat the flue gas. Dry scrubbing systems are used to remove acid gases (such as S0 ₂ and HC1) primarily from combustion sources and for the removal of odorous and corrosive gases from wastewater treatment plant operations, medical waste incinerators, industrial and utility boilers and a few municipal waste combustors. There are a number of dry type scrubbing system designs which consist of two main parts: a device to introduce the acid gas sorbent material into the gas stream and a particulate matter control device to remove reaction products, excess sorbent material as well as any particulate matter already in the flue gas.

The traditional scrubber systems are bulky and non-portable and hence their use in the automobile industry is not envisaged.

A device has been described in US Patent No. US 8,480,798 for C0 ₂ scrubbing using a fluid adsorbent thereby requiring an entirely separate compartment to be placed after the engine and before the exhaust. There is no inbuilt system within the exhaust system of the vehicle for ease and space efficiency. The C0 ₂ absorbed by the 798 patent is stored in a container in gaseous form which further require delicate handling. The requirement of additional heat exchanger and pump further complicates the device of 798 patent. Another patent US Patent No. US 6,866,702 utilizes solid C0 ₂ absorbent chemicals in form of a cement composition thereby resulting in a bulky and fixed system which is not easy to replace or remove.

No effective method or system exists to remove carbon dioxide from vehicle exhausts since existing systems are not portable.

The present invention discloses a carbon scrubbing method is to capture carbon dioxide from vehicular emissions so as to prevent it from entering the atmosphere. Furthermore, with increasing global concerns about climate change there is a continuous need to develop devices such as those disclosed in this application in order to reduce C0 ₂ emissions.

SUMMARY OF INVENTION

The present invention has been made in view of the above-described issue and provides for a method to remove carbon dioxide from vehicular emissions. The purpose of the invention is to provide a scrubbing system for a vehicle, comprising of a scrubbing device designed to remove the emitted C0 ₂ by the vehicle. Said scrubbing device follows a dry scrubbing method using granules of chemicals that absorb carbon dioxide, for example soda lime. Within the said scrubbing system is a device which holds said granules in place as both the exhaust moves through them and the vehicle moves. These granules are preferably held in removable cartridges wherein the granules are sandwiched between wire meshes.

As a preferred embodiment of the invention, the scrubbing device cartridges are places in coiled or twisted pipe. The coiled or twisted pipe serves the following purposes: 1 ) to slow down the gases, so that the reaction between C0 ₂ and the chemical has more time to occur before the gases leave the vehicle. 2) a large length of piping can be fitted into a relatively small volume, making it easily to attach to the underside of a car.

Another preferred embodiment of the invention is to have a locking mechanism for the cartridges in the pipe so as to ensure that the cartridges stay in place and to allow accessibility of the cartridges for replacement as desired. The scrubber system is preferred to be fitted within the exhaust system of the vehicle such as to receive the exhaust of vehicles. There are no portable methods of carbon dioxide scrubbing and no carbon dioxide scrubbing methods exist for cars. The unique features of the invention are the removable cartridges which are easily extracted and replaced and the coiled or twisted pipe that it gives the gases a larger distance over which to react with chemicals while restricting the size of the device. The invention can be used in any vehicle running on the combustion of fossil fuels. The invention results in reduction of vehicular C0 ₂ emissions. . In the device of the invention the C0 ₂ is stored in the actual chemical form and can be released into a container when the cartridges are removed and replaced.

The invention therefore provides for a method and system to remove carbon dioxide from vehicular emissions. The scrubbing system used in the method is designed to remove the emitted C0 ₂ of the vehicle by fixing a scrubbing system in the vehicle exhaust system so as to receive the vehicular emissions or exhaust prior to disposal from the vehicle, said system comprising of one or more scrubbing device fitted within the pipe through a locking mechanism. The scrubbing device is a cartridge comprising granules of chemicals that absorb carbon dioxide, preferably soda lime. Once the exhaust gases to flow through the scrubbing device, the C0 ₂ is absorbed by the scrubbing device before release of the exhaust gases. The scrubbing device is removable and/or reusable. BRIEF DESCRIPTION OF DRAWINGS

The features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which:

Figure 1 A-C: Depict the soda lime cartridge of the invention Figure ID: Gives a few examples of coiled and twisted pipes

Figure 2: Depicts the positioning of the cartridge in the pipe

Figure 3: Depicts the locking mechanism of the cartridges in the pipe

Figure 4a-d: Shows the photograph of one of the embodiment of the locking mechanism of the cartridge in the pipe. Figure 5: Depicts cross section of a cartridge comprising multiple pairs of wire meshes

Figure 6: Depicts top view of various pairs of wire meshes having granules of the C02 absorbing chemicals in different positions.

Figure 7: Depicts a cartridge assembly in the exhaust pipe wherein the edges of the wire mesh at both the ends of the cartridge is visible. Figure 8: Depicts the variation in C0 ₂ concentration with time measured by each of the probes in Example 5.

Figure 9: Depicts the difference between the measurements of the Pre and Post probes, i.e the amount of C0 ₂ absorbed vs time in Example 5.

Figure 10: Depicts the graph of difference between pre and post amount of C0 ₂ absorbed vs time for Example 6

DETAILED DESCRIPTION OF THE INVENTION

Other objects and aspects of the invention will become apparent from the following description of the embodiments with reference to the accompanying drawings, which is set forth hereinafter. The embodiments of the present invention can be modified variously. Thus, the scope of the present invention should be construed not limited to the embodiments to be described herein. The embodiments are provided to better explain the present invention to those of ordinary skill in the art. Further, the elements and areas of the drawings are drawn roughly only, and the scope of the present invention is not limited to the relative sizes, shapes and gaps in the drawings.

The method to remove carbon dioxide from vehicular emissions is disclosed. The disclosed method uses: · Granules of chemicals that absorb carbon dioxide. Examples include soda lime.

Removable Cartridges that consist of wire meshes that hold the granules in place as both the exhaust moves through them and the vehicle moves

Coiled or twisted pipe in order to increase the distance travelled by the exhaust and therefore the time for a chemical reaction to occur, while restricting the size of the device to enable it to be attached to the vehicle

A mechanism to lock the cartridges in place on the pipe

The entire system is then fitted to the exhausts of vehicles. The chemical granules contained in the series of wire-meshes within the coiling pipe reacts with the Carbon dioxide as the exhaust gases pass through the pipe. The air coming out of the disclosed system has a reduced concentration of carbon dioxide. The removable cartridges can then be extracted and replaced.

The invention can be used in any vehicle running on the combustion of fossil fuels. The invention reduces CO ₂ emissions.

EXAMPLE 1

Feasibility of soda lime

An experiment was conducted which verified that the soda lime is feasible for use in vehicles. The experiment showed that soda lime is able to function efficiently and react with carbon dioxide at the high temperatures and in the presence of the pollutants present in vehicle exhausts. It also showed that, at these temperatures, soda lime does not decompose or change form. While other chemicals may be used in the cartridges other than soda lime, the experiment showed soda lime to be practical for such an application.

EXAMPLE 2 Small scale experiment using following material was conducted to validate the use of soda lime as per the invention as disclosed for CO ₂ scrubbing in vehicle exhaust:

• Soda Lime granules

• Test Tubes

• Delivery tubes

• Limewater

• A motorcycle to provide vehicle exhaust gases.

First a control was set up. A rubber pipe was connected from the end of the motorcycle exhaust to an empty glass container. A delivery tube led from A to another container holding limewater. The motorcycle was started and the throttle held constant to ensure that the rate of flow of gases through the apparatus remained constant. The time taken for the limewater to turn milky was measured.

Next, granules of soda lime were placed in the first container and the experiment repeated for the same interval of time with the throttle held at the same position as in the control. This was repeated twice.

It was observed that, in the control experiment, the limewater turned milky, indicating the presence of carbon dioxide.

In the experiments where soda lime was placed in the first container, it was observed that the limewater did not turn milky, indicating the absence of carbon dioxide.

The limewater did not turn milky when exhaust gases were first passed through soda lime. From this, it can be concluded that soda lime does effectively remove carbon dioxide from hot vehicle exhausts.

Furthermore, it was observed that the granules did not melt or otherwise change shape, which makes them viable for use in a cartridge.

In conclusion, this experiment shows that soda lime seems perfect for use in cartridges to absorb carbon dioxide from vehicle exhausts.

EXAMPLE 3

Soda lime cartridges in pipe The wire mesh cartridges containing soda lime granules arranged in various manners, such as parallel pipes, inter-twined pipes, flexible pipes, pipes in series etc. are the various embodiments for the C0 ₂ scrubbing.

Figures 1A-D show the construction of a removable cartridge, and the coiled pipes in which the cartridges are to be placed. The cartridge itself is a cylinder containing granules of carbon dioxide absorbing chemicals. The tops and bottoms of the cylinder are made of wire meshes, fine enough to hold the granules in place, the construction of the cartridge is shown in Figure 1 A Figure IB and 1C show what the cartridge will look like. Figure ID gives a few examples of suitable coiled pipes for use in the device. Figures 1A depict the blown up description of the cartridge wherein the solid ring of the cartridge (also shown in Figure 1C side view) is filled with granules and then both sides are covered with the wire mesh. The top view of the cartridge with the soda lime granules being visible through the wire mesh is depicted in Figure IB. Some examples of coiled pipes the cartridges are to be fitted into are shown in Figure ID. The cartridges can also be placed in the pipe in various manners. Alone or in a series as depicted in Figure 2. Figure 2 shows the placement of the cartridges into a section of the coiled pipes. The cross sectional area of the cartridges must be flush with the cross sectional area of the pipe.

EXAMPLE 4

Locking mechanism for cartridges The pipes containing cartridges have various locking mechanism including the one disclosed in figure two. The locks are so arranged so as to allow replacement of one or two or more or all cartridges at one time. Figure 3 shows a preferred embodiment of the locking mechanism to attach the cartridge to the pipe. Screw-like arms are attached to the cartridge, along with caps on either end which can be screwed onto adjoining sections of the pipe. For this sort of locking mechanism, the pipe itself must have a helical groove at the ends where the cartridges are to be placed so that they can be screwed on.

Figure 4a shows a cartridge locking mechanism to implement the invention. The central hollow part is where the scrubber is housed and the on either side the exhaust pipe is present which can be curved or coiled as desired. Figure 4b shows the grooves on the outside of the pipe and Figure 4c shows the grooves on the inside of the scrubbing device. In this example the grooves on the exhaust pipe are screwed into the grooves on the inside of the scrubbing chamber, holding it in place as depicted in Figure 4d.

EXAMPLE 5

The invention was tested in a motor plant for its working and efficiency and for one of the experiments a cartridge using a 15 cm long section of an 80 dia pipe (88.9 mm in diameter). The cartridge secured to the pipe was to secure to the test bed with triangular flanges. The wire mesh space was 2X2mm. Granules or pieces of soda lime which would be held together within mesh and not pass through the mesh was used to fill the cartridge and then it attached to the exhaust. The Figure 7 shows a cartridge assembly design used in the example. The following measurements were recorded

1. Amount of carbon dioxide absorbed by the cartridge- Horiba CO ₂ probes were used for this measurement. One probe was placed before the cartridge and directly after the engine (pre- probe) and the second probe was placed after the cartridge (post-probe). The difference in the readings recorded by the two probes was used to calculate the amount of carbon dioxide absorbed by the cartridge.

2. The rate in change of absorption of carbon dioxide- the C0 ₂ probes were set to take readings at a frequency of l OHz at frequent time intervals.

3. The variation in absorption of C0 ₂ with respect to the temperature- The temperature of the exhaust was varied by increasing the rpms of the engine and using the accelerator pedal.

4. The increase in back pressure caused by the cartridge was also measured by using a Horiba probe.

The engine was started at idling (700 rpm) and the C0 ₂ and pressure were recorded through the probe. The temperature was increased at regular intervals of 5 minutes by increasing the rpms of the engine.

1200 20% 5

1500 30% 5

The experiment was run as shown in the table above. The experiment was thus for testing for a total of 20 minutes with the probes making measurements every 0.1 seconds. The experiment was run continuously with no stoppage or pauses. Observations

The soda lime resulted in a decrease in carbon dioxide of 1000 parts per million (ppm) initially. This amount fell to 400ppm by the end of the experiment

Despite the falling difference in the C0 ₂ measured pre and post, whenever temperature was increased, a small spike in the amount of C0 ₂ observed was measured. · It was observed that above 185 Celsius, the amount of C0 ₂ measured post the cartridge was greater than that measured pre. i.e Carbon dioxide was being released.

At constant temperature, the rate of absorption of C0 ₂ did decrease slowly during the time the measurements were being taken.

Back pressure, which is the pressure felt by the system and measured immediately after the turbocharger was measured to be 60 millibars at idling without the cartridge.

Back Pressure at idling, with the cartridge was measured to be 100 millibars i.e there was 66.67% increase.

Figure 8 graph shows the variation in C0 ₂ concentration with time measured by each of the probes. The blue line is the C0 ₂ concentration before the cartridge (Pre) and the red line represents the C0 ₂ concentration after the concentration (Post). Concentration is measured on the y axis in ppm (parts per million) and time is measured on the x axis in seconds. The spikes and drops in C0 ₂ concentration occur at points when the throttle was changed, increasing the temperature and flow rate of exhaust gases.

It is evident from Figure 8 that the cartridge absorbed C0 ₂ as the blue line lies above the red line for most part of the graph. The difference between the two lines was however only a small fraction of the total carbon dioxide emissions which shows that the cartridge on its own is quite inefficient. In order to improve the efficiency of the system multiple cartridges and/or coiled pipes are used so as to slow down the exhaust gases and provide sufficient time for the soda lime to react with the carbon dioxide.

It was observed that there was small period of time when the CO2 concentration measured by the Post probe was greater than that of the Pre probe. This was at temperatures above 200 degrees Celsius, when the reaction that governs the absorption of C0 ₂ by soda lime is reversed and the product (calcium carbonate) releases carbon dioxide.

Figure 9 shows the difference between the measurements of the Pre and Post probes, i.e the amount of C0 ₂ absorbed, vs time. Again, the sudden spikes in the said figure correlate with the engine's rpms and hence the temperature of the exhaust gases have been increased. The initial rapid decline in C0 ₂ absorption, until about 100 seconds appears to be the result of the exhaust warming gradually to 85 degrees Celsius. The first spike appears when temperature is increased from 85 degrees Celsius to 155 degrees Celsius. The second spike appears at an increase from 155 to 185. Because this reversed the process and resulted in C0 ₂ being emitted rather than released, the temperature was reduced once more to 155 degrees Celsius.

Conclusion drawn from the data:

1) The cartridge can successfully reduce C0 ₂ emissions from vehicles.

2) The efficiency of the device was very low, averaging below 5% in terms of percentage of C02 absorbed. It is likely that the reason of the low efficiency is for the fact that were moving through the cartridge too quickly for the soda lime inside to react effectively. Coiled pipe and/or multiple cartridges can slow down the gases and allow more time for the chemical inside the cartridge to react with the carbon dioxide per second.

3) The spike in C0 ₂ absorption and reversal of chemical reaction above 185 Celsius requires that a soda lime cartridge be placed neither too close to the engine (where temperatures exceed 350 degrees Celsius) nor too far (where temperatures can go below 85 degrees Celsius). An optimal placement for a cartridge would be after the catalytic converter as the catalytic converter uses some of the heat from the gases to operate, the gas emerging from it will be cool enough for the cartridge but not so cool as to reduce efficiency. Another option would be to use other chemicals in place of soda lime. Yet another option would be to have a coolant before the exhaust gas enters the cartridge so as to have desired temperature of the flowing exhaust gas within the cartridge. 4) There was a significant increase in back pressure due to the cartridge, this increase would be further exacerbated by a coiled pipe and/or efficient arrangement of wire meshes (see Figure 5) and/or granules within the cartridges (see Figure 6).

A coiled pipe which alternates in diameter with some lengths of it being narrow and others being wide can be used for better efficiency. The wider stretches of pipe will further slow down the exhaust gases and allow the device to become more efficient if the cartridges are placed in these sections. The narrow sections of the pipe will speed up the exhaust gases during the time that they are travelling between cartridges and help counteract the increase in back pressure. EXAMPLE 6

Another embodiment was tested in a motor plant wherein the cartridge design having three number of 'meshes' was used which demonstrated that the design of the invention leads to significant decrease in backpressure. The amount of soda lime granules used was kept the same as Example 5 As in the Example 5 experiment, the similar measurements were taken following similar protocol.

Observations

Figure 10 shows the results on a graph of the experiment conducted in Example 6. The amount of C0 ₂ absorbed is shown in the y axis in hundreds of parts per million. The graph of Figure 10 depicts the difference between pre and post cartridge amount of CO ₂ absorbed vs time. The fluctuations are accounted for by the fact that the flow rate and temperature in the exhaust fluctuated a little with time. The frequency of the readings and the frequency of the cycle of the engine also collude to form the waveform- like graph as seen in Figure 10.

Back pressure. At idling, back pressure is 60 bars and once the engine is started, back pressure escalated to about 83 bars. This is only a 23% increase in back pressure as compared to a 66.67% increase with the single mesh cartridge design of Example 5. This is the most significant difference in result that the new design does reduce back pressure. Using more meshes would further reduce the back pressure generated by the scrubber and allow the coiled pipe to be used in such a way as not to significantly affect the vehicles fuel efficiency. The cartridge configuration of the invention does not hinder the absorption of C0 ₂ and is at least 2-3% more efficient. The efficiency can therefore be further enhanced though other embodiments of the invention by changing several other factors:

• Increasing the number of meshes to increase efficiency. The number of meshes can be increased feasibly, depending on granule size. For example 1 mesh per cm of pipe, resulting in 10 meshes in 10 centimeters of pipe.

• Use of a coiled pipe helps in slowing down the gases and allowing them to react with the reagents. Further, the back pressure generated by the coiled pipe is offset by lowered back pressure resulting from the new system.

• Use of more efficient reagent than soda lime such as lithium hydroxide will increase the efficiency of the scrubber design.

Various embodiments are possible of the invention other than those disclosed above and are easily comprehended by a person skilled in the art. The invention encompasses all such embodiments within its scope. While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention