JP2024540071A - Graphene-Based Adsorbent for EVAP Canisters Used in Vehicle Emissions Management Systems - Google Patents

Abstract

An evaporative emissions control system for a motor vehicle for reducing evaporative emissions, the system having an evaporative canister coupled to a fuel tank, the canister capable of adsorbing hydrocarbons and including an adsorbent material selected from the group of activated graphene derivatives including but not limited to single layer graphene, few layer graphene, graphene oxide, reduced graphene oxide, and functionalized graphene, a vapor inlet of the canister connected to the fuel tank and a purge outlet of the canister connected to an air induction system, the adsorbent material adsorbing fuel vapors when the engine is not running and desorbing fuel vapors when the engine is running.

Description

The present invention generally relates to adsorbents incorporated into EVAP canisters. More specifically, the present invention discloses graphene-based adsorbents that are utilized in evaporative emission management systems and can include either activated graphene derivatives or graphene-based foam compositions.

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application No. 17/975,102, filed October 27, 2022, which claims priority to U.S. Patent Application No. 63/274,158, filed November 1, 2021, each of which is incorporated by reference in its entirety, including any drawings.

Evaporative emission control (EVAP) systems seal a vehicle's fuel system to prevent fuel vapors from the fuel tank and fuel system from escaping into the atmosphere. This is important because fuel vapors contain various hydrocarbons that form smog when they react with air and sunlight. As we all know, gasoline evaporates very quickly, so if the fuel system is open to the atmosphere, the vehicle can pollute throughout the day (especially during the day), even when it is not turned on. Studies have shown that these uncontrolled evaporative emissions can account for 20% of the pollutants produced by vehicles.

One of the main components of a typical EVAP system is the fuel tank that stores the gasoline. The operation of the filling pump is such that it stops the flow of gas when the nozzle detects the achieved filling level in the tank. This is to maintain a minimum expansion space at the top so that the fuel stored in the tank can expand without overflowing or causing a leak in the EVAP system.

The gas cap seals the gas tank's filler neck from the outside air. A damaged or missing gas cap is the most common cause of EVAP system fault codes that can cause the engine warning light to illuminate.

The liquid vapor separator prevents liquid gasoline from entering the EVAP canister, which would tax its capacity to store fuel vapors.

The EVAP canister is connected to the fuel tank by a tank vent line and typically contains 1-2 pounds (0.45-0.91 kg) of activated carbon that acts like a sponge by absorbing and storing fuel vapors until a purge valve is opened allowing the engine intake vacuum to wick (desorb) the fuel vapors from the activated carbon into the engine intake manifold. A vent control valve allows the flow of fuel vapors from the fuel tank into the EVAP canister.

Engine control systems dedicated to emissions minimization facilitate purging of the canister and, during engine operation, remove adsorbed fuel vapors from the activated carbon by purging the canister system with ambient air that is drawn into the canister through the vent port and flows through the adsorbent carbon bed, allowing vaporized hydrocarbons to be desorbed through the purge port and into the engine intake. The regenerated carbon is then ready to adsorb additional fuel vapors and the cycle continues. Thus, the "EVAP" canister plays a key role in modern evaporative emissions control technology by temporarily adsorbing vaporized hydrocarbons and allowing only clean air to be exhausted.

The purge valve/sensor allows engine intake vacuum to draw fuel vapors up from the EVAP canister into the engine intake manifold (the desorption process). The vent hose provides a means for fuel vapors to flow to the various components of the EVAP system.

The fuel tank pressure sensor monitors the pressure for leaks and overpressure. Finally, the fuel level sensor monitors the fuel level in the tank.

An example of an existing evaporative emissions control system with a new adsorbent is disclosed in U.S. Patent No. 5,393,323 to Reddy, which teaches an adsorbent such as activated carbon having a nearly linear isotherm provided in the system.

It is further noted that, in contrast to exhaust emissions, evaporative emissions are colorless and therefore present a risk of escaping unnoticed. If allowed to escape, these vaporized hydrocarbons can react with air in the presence of sunlight, creating smog that is harmful to humans and the entire ecosystem.

Therefore, the primary objective of automotive evaporative emission control technology is to prevent volatile organic compounds (VOCs), such as vaporized hydrocarbons, from escaping into the atmosphere and meeting EPA/CARB standards under LEV II/LEV III emission standards. The above-mentioned "EVAP canister" plays a key role in modern evaporative emission control technology by temporarily adsorbing vaporized hydrocarbons and allowing only clean air to be exhausted. The size of the canister and the volume of the adsorbent are further typically selected to match the expected fuel vapor evaporation associated with a particular application.

The primary sources of evaporative emissions are refueling and diurnal emissions. During refueling, as new fuel is added to a vehicle's gasoline tank through the dispenser nozzle, vaporized hydrocarbons (such as butane and pentane) displaced from the gasoline tank are emitted into the canister. Diurnal emissions are caused by fuel vapors that are generated as a result of day-night temperature fluctuations. The canister contains a sorbent material such as high surface area (activated) carbon, and the size of the canister and the volume of the sorbent material are selected to match the expected evaporation of fuel vapors.

Gasoline vapors, again composed of hydrocarbon molecules such as butanes and pentanes, are attracted to the non-polar surface of the activated carbon where they are temporarily adsorbed (physisorbed), allowing only clean air to escape through the vent port into the atmosphere. Because the refueling process produces high concentrations of hydrocarbons, advanced canisters use multiple chambers and specially designed carbon adsorbents to achieve low or no evaporative emissions.
As is further known, the long-term performance of activated carbon adsorbents used in conventional EVAP canisters has certain limitations. If the desorption process is not completed, traces of hydrocarbons remain in the adsorbent, and the adsorption capacity decreases over time. As a result, during refueling or diurnal losses, the air flow from the fuel tank to the canister and out through the vent port to the atmosphere may contain traces of harmful gasoline components that are not adsorbed due to the decrease in the adsorption capacity of the adsorbent. Therefore, although activated carbon in the form of extruded pellets has traditionally been the primary choice for canister filling, such persistent "bleed" problems remain a challenge.

U.S. Pat. No. 7,467,620

The present invention seeks to address the shortcomings of conventional carbon-based adsorbents and instead discloses a graphene-based adsorbent (including either a powder, pellet, foam, felt or other composition) for use in EVAP canisters that form part of an evaporative emissions management system to adsorb high concentrations of evaporative hydrocarbons to reduce emissions from the canister.

Graphene derivatives are incorporated into a polymer in the form of either pellets or foams that are used to maintain the volume of the canister and allow proper adsorption of fuel vapors within the canister. Further graphene derivatives are incorporated into a polymer in the form of felt that is used to compress the adsorbent within the canister.

The group of graphene derivatives includes, but is not limited to, single layer graphene, few layer graphene, graphene oxide, reduced graphene oxide, and functionalized graphene. The loading concentration of graphene derivatives for foams and felts can vary from 0.1 weight percent to 60 weight percent. The polymer is a thermoplastic polymer and can be selected from, but is not limited to, polyurethane, polyester, polypropylene, nylon 6, nylon 6,6, nylon 12, nylon 6,12, polyethylene, terephthalate, polybutylene, polyphthalamide, polyoxymethylene, polycarbonate, and polyvinyl chloride.

In another embodiment, the adsorbent may be a combination of graphene derivatives incorporated into either a foam or a felt and lignocellulosic material or charcoal.

A corresponding evaporative emissions control system for a motor vehicle for reducing evaporative emissions includes an evaporative canister coupled to a fuel tank. The canister includes a graphene sorbent composition, the canister has a vapor inlet connected to the fuel tank, and a purge outlet connected to an air induction system. In operation, the sorbent adsorbs fuel vapors when the engine is not running and desorbs fuel vapors when the engine is running.

A further feature again includes that the graphene adsorbent is provided as either a foam, a felt, or as a powder such as extruded into pellet form. In one variation, an organic polymer binder effects pelletization of the powder adsorbent into pellet form. The binder may further be cellulosic.

Other features include that the graphene adsorbent composition is manufactured by an extrusion process and a low temperature drying process to maintain a high surface area and optimal pore size to provide adequate adsorption and desorption of vaporized hydrocarbons.

Reference is now made to the accompanying drawings, in which like reference numerals refer to like parts throughout the several views when read in conjunction with the following detailed description.

FIG. 1 is a schematic diagram of an overall evaporative emissions control system utilizing a graphene-based sorbent in an EVAP vapor canister in accordance with one application of the present invention.

FIG. 2 is a partially exploded cross-sectional plan view of an EVAP canister as used in the evaporative emissions control system of FIG. 1 , showing a first non-limiting variation in which graphene derivatives are incorporated into a volumetric compensator of polymer foam surrounded by a volume of additional adsorbent, with a first felt layer disposed at a first end of the canister where the load and purge lines are attached, and a second felt layer disposed at an opposite end of the canister in communication with a fresh air port.

FIG. 3 is a diagram of a canister similar to that shown in FIG. 2 including a combination of graphene derivative and lignocellulose incorporated into a volumetric compensator polymer foam according to a further variant.

FIG. 3 is a diagram of a canister similar to that shown in FIG. 2 including a combination of graphene derivative and charcoal incorporated in a volumetric compensator polymer foam according to a further modification.

FIG. 3 is a diagram of another variation of a canister similar to that shown in FIG. 2, again including a combination of graphene derivative incorporated into the volume compensator polymer foam and further graphene derivative incorporated into both felt layers located at opposite ends of the canister.

FIG. 6 is a diagram of a further variation of a canister which combines the aspects of FIGS. 3 and 5 whereby the volumetric compensator polymer foam incorporates graphene derivative along with lignocellulose, and in addition further graphene derivative is incorporated into both of the felt layers located at opposite ends of the canister.

FIG. 6 is a diagram of a further variation of a canister combining the aspects of FIGS. 4 and 5 whereby the volume compensator polymer foam incorporates graphene derivative along with charcoal, in addition further graphene derivative is incorporated into both of the felt layers located at opposite ends of the canister.

FIG. 11 is a diagram of a further variant of the canister combining a graphene derivative incorporated into a volumetric compensator polymer foam surrounded by an adsorbent with further graphene derivative and lignocellulose incorporated into both felt layers at opposite ends of the canister.

FIG. 11 is a diagram of a further variation of the canister combining a graphene derivative incorporated with lignocellulose in a volumetric compensator polymer foam surrounded by an adsorbent, with further graphene derivative and lignocellulose incorporated into both felt layers at opposite ends of the canister.

FIG. 13 is a diagram of a further variation of the canister combining graphene derivative incorporated with charcoal in a volumetric compensator polymer foam surrounded by an adsorbent, with further graphene derivative and lignocellulose incorporated into both felt layers at opposite ends of the canister.

FIG. 13 is a diagram of a further variation of the canister combining a graphene derivative incorporated into a volumetric compensator polymer foam surrounded by an adsorbent with further graphene derivative and charcoal incorporated into both felt layers at opposite ends of the canister.

FIG. 13 is a diagram of a further variation of the canister combining graphene derivative incorporated with lignocellulose in a volumetric compensator polymer foam surrounded by an adsorbent, with further graphene derivative and charcoal incorporated into both felt layers at opposite ends of the canister.

FIG. 13 is a diagram of a further variation of the canister combining a graphene derivative incorporated with charcoal in a volumetric compensator polymer foam surrounded by an adsorbent with further graphene derivative and charcoal incorporated into both felt layers at opposite ends of the canister.

FIG. 13 shows a further variation of the canister incorporating graphene derivatives including either graphene pellets, foam or felt incorporated into the outer adsorbent material, with a volume compensator foam sandwiched between the outer adsorbents, combined with an outer felt layer attached to either end of the canister.

FIG. 15 is a view similar to FIG. 14 further including lignocellulose incorporated with graphene derivative in an outer adsorbent material surrounding the compensator foam interior, again with an outer felt layer at the opposite end of the EVAP canister.

FIG. 16 is a similar view to FIG. 15, in which lignocellulose incorporated with graphene derivative has been substituted for charcoal in the outer adsorbent surrounding the volumetric compensator foam interior, again further combined with an outer felt layer of the EVAP canister.

FIG. 1 shows a further cross-sectional view of a canister similar to that described above, incorporating a foam or felt adsorbent material comprising any combination of graphene derivatives, lignocellulose, and charcoal, along with an outer felt layer also comprising any combination of graphene derivatives, lignocellulose, and charcoal.

With reference to the accompanying drawings, the present invention seeks to address the shortcomings of conventional carbon-based adsorbents and instead discloses a graphene-based adsorbent for use in EVAP canisters that form part of evaporative emissions management systems.

Figure 1 is a schematic diagram of an evaporative emissions control system, generally referenced 10, using the novel sorbent material of the present invention capable of sorbing hydrocarbons. The system includes a fuel tank 12 with an extending fill neck 14 and a sealed fuel cap 16. The gasoline tank is shown in cross section, showing liquid gasoline defining a fill level 18 that is read by a fuel level sensor 22. Above the fill level, the vacant expansion space or volume at the top of the tank is occupied by fuel vapor 24 (e.g., pentane, butane, etc.). A fuel tank pressure sensor 26 is also located within the tank 12 and, in combination with the fuel level sensor 22, provides measurements of the fill level and tank pressure to an appropriate powertrain control module (PCM) 28.

An EVAP vapor canister 30 is provided and communicated by a vapor inlet line 32 extending from the fuel tank 12, which communicates with a vent control valve that allows the flow of fuel vapor from the fuel tank to the EVAP canister 30. An EVAP vent 33 extending from the canister 30 includes a normally open EVAP solenoid valve 34. A further line 36 extends from the canister 30 to a purge flow sensor 38, an EVAP purge sensor (normally closed) 40, which is connected to the air induction system, allowing the engine intake vacuum to siphon off a precise amount of fuel vapor previously adsorbed in the EVAP canister for delivery to the engine intake manifold and eventual combustion. The PCM module 28 also receives inputs from each of the EVAP vent solenoid 34, the purge flow sensor 38, and the EVAP purge solenoid 40.

As further described with further reference to each of the following Figures 2-16, the canister 30 includes a graphene adsorbent composition, and in operation, the adsorbent adsorbs fuel vapors discharged from the fuel tank when the engine is not running, and then desorbs and returns the fuel vapor to the engine intake manifold when the engine is running. Although a straight canister is shown in each of the figures following Figure 2, it is further understood that all shapes of the canister, including non-linear shapes, are contemplated within the scope of the present invention.

As further described, the graphene adsorbent is provided either as an extruded powder in the form of a foam, felt or pellets, and the graphene or graphene derivative is further activated using either chemical or thermal methods. An organic polymer binder improves adhesion of the graphene adsorbent to the surface of the canister. The binder may also be cellulosic. Other features include that the graphene adsorbent composition is manufactured by an extrusion process and a low temperature drying process to have a high surface area and optimal pore size to provide suitable adsorption and desorption of vaporized hydrocarbons.

Proceeding to FIG. 2, a partially exploded cutaway plan view of an EVAP canister as used in the evaporative emissions control system of FIG. 1 is shown generally at 50. The EVAP canister includes a main housing 52 (also shown in non-limiting form as having a cylindrical shape with a hollow interior).

The housing 52 is capable of adsorbing hydrocarbons and again encapsulates a quantity of adsorbent material including, but not limited to, graphene, few layer graphene, graphene oxide, reduced graphene oxide, and functionalized graphene. The loading concentration of the graphene derivative for the foam and felt can vary from 0.1 weight percent to 60 weight percent. The adsorbent material is shown as upper and lower sections 54, 56 separated by and surrounding a further quantity of polymer-based foam having graphene derivative 58 incorporated into the polymer, which is used to maintain the volume of the canister and allow proper adsorption of the fuel vapors within the canister.

Without being limited thereto, the group of graphene derivatives can again include, but are not limited to, any of single layer graphene, few layer graphene, graphene oxide, reduced graphene oxide, and functionalized graphene. The loading concentration of the graphene derivatives can vary from 0.1 weight percent to 50 weight percent. The polymer can include any of the thermoplastic polymers and can be selected from, but are not limited to, polyurethane, polyester, polypropylene, nylon 6, nylon 6,6, nylon 12, nylon 6,12, polyethylene, terephthalate, polybutylene, polyphthalamide, polyoxymethylene, polycarbonate, and polyvinyl chloride.

A first felt layer 60 is located at one end of the canister main housing 52 and a top cover 62 incorporating a fresh air port 64 is attached over the first felt layer 60. A second felt layer 66 is located at the opposite end of the canister main housing 52 and a further cover 68 incorporating a load line 70 and a purge line 72, respectively, is attached over the second felt layer 66. The felt layer is provided in each embodiment to assist in compressing the adsorbent within the canister.

The operation of the EVAP canister 50 is similar to that described above, including communication with the vapor canister by a vapor inlet (load) line 70 that extends to the fuel tank, again in communication with a vent control valve that allows the flow of fuel vapor from the fuel tank to the EVAP canister. The EVAP vent (also air port 64) extends from the canister 50 and includes a normally open EVAP solenoid valve (see again 34 in FIG. 1), and a further line 72 extends from the canister 50 to a purge flow sensor (previously 38 as described in FIG. 1), an EVAP purge sensor 40 (normally closed), which is connected to the air induction system, allowing the engine intake vacuum to siphon off (desorb) the precise amount of fuel vapor previously adsorbed in the EVAP canister for delivery to the engine intake manifold and eventual combustion during engine operation.

With continued reference to Figures 3-16, similar EVAP canister structures are shown with identical components numbered repeatedly and the description limited to the compositional differences disclosed in Figure 2. Figure 3 is a view of a canister (generally 74) similar to that shown in Figure 2, except that polymer foam composition 58' includes a combination of both graphene derivative and lignocellulose incorporated into the volumetric compensator foam. Figure 4 is a view of a canister 76 similar to that shown in Figure 2, in relevant part, including a combination of graphene derivative and charcoal incorporated into a further version of the volumetric compensator polymer foam designated 58" according to a further modification.

Figure 5 is an illustration of another variation 78 of a canister similar to that shown in Figure 2, again including a combination of graphene derivatives incorporated into the volumetric compensator polymer foam (58) and additional graphene derivatives incorporated into both felt layers (further indicated at 62' and 66') located at the opposite ends of the canister.

Figure 6 is an illustration of a further variation 80 of a canister combining the aspects of Figures 3 and 5, whereby the volumetric compensator polymer foam incorporates graphene derivative along with lignocellulose (again 58'), and in addition further graphene derivative is incorporated into both felt layers (60' and 66') located at opposite ends of the canister.

Figure 7 is an illustration of a further variation 82 of the canister combining the aspects of Figures 4 and 5 whereby the volumetric compensator polymer foam incorporates graphene derivative along with charcoal (again 58') and in addition further graphene derivative is incorporated into both felt layers (60' and 66') located at opposite ends of the canister.

Figure 8 is an illustration of a further variation of the canister 84, again combining graphene derivatives incorporated into a volumetric compensator polymer foam (58) surrounded by adsorbent material (54 and 56) with further graphene derivatives and lignocellulose incorporated into both felt layers (designated 60" and 66") at the opposite ends of the canister.

Figure 9 is a diagram 86 of a further variation of the canister combining graphene derivatives incorporated with lignocellulose in a volumetric compensator polymer foam (again 58') surrounded by adsorbent material (again 54 and 56) with further graphene derivatives and lignocellulose incorporated in both 60" and 66" felt layers at the opposite ends of the canister.

Figure 10 is an illustration of a further variation of the canister 88, combining graphene derivatives incorporated with charcoal in a volumetric compensator polymer foam (58') surrounded by adsorbent (again enclosing volume 54/56) with further graphene derivatives and lignocellulose again incorporated in both the 60" and 66" felt layers at the opposite end of the canister.

Figure 11 is an illustration of a further variation of the canister 90, again combining graphene derivatives incorporated into a volumetric compensator polymer foam 58 surrounded by adsorbent material (54/56) with further graphene derivatives and charcoal incorporated into both felt layers (designated 60" and 66") at the opposite ends of the canister.

Figure 12 is an illustration of a further variation of the canister 92, combining graphene derivatives incorporated with lignocellulose in a volumetric polymer foam (58') surrounded by an adsorbent, with further graphene derivatives and charcoal incorporated in both felt layers (again 60" and 66") located at the opposite ends of the canister.

Figure 13 is an illustration of a further variation of the canister 94, combining graphene derivatives incorporated with charcoal in a volumetric compensator polymer foam (58") surrounded by an adsorbent (54/56), with further graphene derivatives and charcoal incorporated in both felt layers (again 60" and 66") at the opposite ends of the canister.

Figure 14 shows a further variation 96 of the canister incorporating graphene derivatives, including pellets etc., incorporated into the outer adsorbents (see 98 and 100) with a volumetric compensator foam interior (102) sandwiched between the outer adsorbents, combining this with outer felt layers (104 and 106) attached to either end of the canister, instead of the felt layers as previously shown in Figures 2-13.

Figure 15 is a view (108) similar to Figure 14, further including lignocellulose incorporated with graphene derivatives in the outer adsorbent material (see 96' and 98') (which surround the volumetric compensator foam interior 102), again with outer felt layers 104 and 106 at opposite ends of the EVAP canister.

Figure 16 is a view (110) similar to Figure 15, where lignocellulose incorporated with graphene derivatives has been substituted for charcoal in the outer adsorbent (see 96" and 98") surrounding the volumetric compensator foam interior 102, again further combined with the outer felt layers 104 and 106 of the EVAP canister 110.

Figure 17 shows a further cross-sectional view of a canister (generally 112) similar to that described above, incorporating either a foam or felt adsorbent material 114, which is provided with any combination of graphene derivatives, lignocellulose, and charcoal. Also shown are outer felt layers 116 and 118, which also include any combination of graphene derivatives, lignocellulose, and charcoal.

Having described the present invention, other and further preferred embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from the scope of the appended claims. It is further understood that the detailed description and drawings support the disclosure, the scope of which is defined by the claims. Although some of the best modes and other embodiments for carrying out the teachings set forth in the claims have been described in detail, there are various alternative designs and embodiments for carrying out the disclosure as defined in the appended claims.

It is further understood that the foregoing disclosure is not intended to limit the disclosure to the precise form or particular field of use disclosed. Accordingly, various alternative embodiments and/or modifications to the disclosure are possible in light of the present disclosure, whether expressly described or implied herein. Having thus described an embodiment of the present disclosure, those skilled in the art will recognize that changes in form and detail can be made without departing from the scope of the present disclosure. Accordingly, the present disclosure is limited only by the scope of the claims.

In the foregoing specification, the disclosure has been described with reference to specific embodiments. However, as those skilled in the art will appreciate, the various embodiments disclosed herein can be modified or embodied in various other ways without departing from the spirit and scope of the present disclosure. Thus, this description should be considered as illustrative and is intended to teach those skilled in the art how to make and use the various embodiments of the present disclosure. It should be understood that the forms of the disclosure shown and described herein should be taken as representative embodiments. The elements, materials, processes or steps typically shown and described herein may be replaced with equivalent elements, materials, processes or steps. Also, certain features of the present disclosure may be utilized independently of the use of other features, all of which will be apparent to those skilled in the art after the benefit of this description of the present disclosure. The terms "comprises," "includes," "incorporates," "consists of," "has," "is," and the like, used to describe and claim the present disclosure, are intended to be interpreted in a non-exclusive manner, i.e., allowing for the presence of items, components or elements not expressly described. References to the singular should be interpreted to relate to the plural as well.

Furthermore, the various embodiments disclosed herein should be construed in an illustrative and explanatory sense, and should not be construed as limiting the present disclosure in any way. All connector references (e.g., attached, secured, coupled, connected, etc.) are used only to aid the reader's understanding of the present disclosure, and cannot impose limitations on the position, orientation, or use of the systems and/or methods specifically disclosed herein. Thus, connector references, if any, should be interpreted broadly. Also, such connector references do not necessarily imply that two elements are directly connected to each other.

Furthermore, without limitation, all numerical terms such as "first," "second," "third," "primary," "secondary," "main," or any other general and/or numerical terms should be construed merely as identifiers to aid the reader in understanding the various elements, embodiments, variations and/or modifications of the present disclosure, and in particular do not impose any limitations as to the order or priority of any element, embodiment, variation and/or modification relative to other elements, embodiments, variations and/or modifications.

It will also be understood that one or more of the elements shown in the drawings/diagrams may be implemented in a more separate or integrated manner, or even removed or rendered inoperative in some cases, as may be useful according to a particular application. Furthermore, the signal hatches in the drawings/diagrams are to be considered as illustrative only and not limiting, unless otherwise noted.

Claims (20)

1. An evaporative emissions control system for a motor vehicle for reducing evaporative emissions, comprising:
an evaporative canister coupled to a fuel tank, the canister being capable of adsorbing hydrocarbons and comprising an adsorbent selected from the group of activated graphene derivatives including but not limited to single layer graphene, few layer graphene, graphene oxide, reduced graphene oxide, and functionalized graphene;
a vapor inlet of the canister connected to the fuel tank;
a purge outlet of the canister connected to an air induction system;
An evaporative emissions control system, wherein the adsorbent adsorbs fuel vapors when the engine is not operating and desorbs fuel vapors when the engine is operating. The invention of claim 1 further comprises that the graphene or graphene derivative adsorbent is provided as either a powder extruded pellet, a die-cut pellet or a molded pellet, and is activated using either a chemical or thermal method. 10. The invention of claim 1 further comprising the sorbent being provided as a combination of powdered extruded, stamped or molded pellets and a layer of polymeric foam or felt which expands into the canister to compress the sorbent to maintain the interior volume of the canister and enable proper adsorption of the hydrocarbons.
The invention of claim 2 further comprises an organic polymer binder for maintaining the shape of the pellet or granular adsorptive material. The invention of claim 4 further includes that the organic binder is cellulosic. The invention of claim 1 further includes that the adsorbent is manufactured by an extrusion process and a low temperature drying process to maintain a high surface area and optimal pore size suitable for adsorption and desorption of vaporized hydrocarbons. The invention of claim 1, wherein the adsorbent further comprises either a lignocellulosic or charcoal material in combination with the activated graphene derivative. The invention of claim 3 further includes providing a loading concentration of the graphene derivative in the foam or felt layer in the range of 0.1 to 60 weight percent. The invention of claim 3 further comprising, but not limited to, the polymer foam selected from the group consisting of polyurethane, polyester, polypropylene, nylon 6, nylon 6,6, nylon 12, nylon 6,12, polyethylene, terephthalate, polybutylene, polyphthalamide, polyoxymethylene, polycarbonate, and polyvinyl chloride. The invention of claim 3, wherein the polymer further comprises a thermoplastic polymer selected from, but not limited to, polyurethane, polyester, polypropylene, nylon 6, nylon 6,6, nylon 12, nylon 6,12, polyethylene, terephthalate, polybutylene, polyphthalamide, polyoxymethylene, polycarbonate, and polyvinyl chloride. The invention of claim 1, wherein the adsorbent further comprises a foam or felt incorporating any combination of graphene derivatives, lignocellulose, and charcoal. 1. An evaporative emissions control system for a motor vehicle for reducing evaporative emissions, comprising:
an evaporative canister coupled to a fuel tank, the canister being provided as either a powder extruded pellet, a die-cut pellet, or a molded pellet, and including an adsorbent material capable of adsorbing hydrocarbons, the adsorbent material being selected from the group of activated graphene derivatives including, but not limited to, single layer graphene, few layer graphene, graphene oxide, reduced graphene oxide, and functionalized graphene;
a cellulosic organic polymer binder for maintaining the shape of the adsorbent pellet material;
a vapor inlet of the canister connected to the fuel tank;
a purge outlet of the canister connected to an air induction system;
The evaporative emissions control system, wherein the adsorbent adsorbs fuel vapors when the engine is not operating and desorbs fuel vapors when the engine is operating. The invention of claim 12 further comprises the sorbent material being provided as a polymer foam, and either the foam or a felt outer layer expanding into the canister to compress the sorbent material to maintain the interior volume of the canister and enable the sorption of the hydrocarbons. The invention of claim 12 further comprises that the adsorbent is manufactured by an extrusion process and a low temperature drying process to maintain a high surface area and optimal pore size suitable for adsorption and desorption of vaporized hydrocarbons. The invention of claim 12, wherein the adsorbent further comprises either a lignocellulosic or charcoal material in combination with the activated graphene derivative. The invention of claim 13 further comprises providing a loading concentration of the graphene derivative in the foam or felt layer in the range of 0.1 to 60 weight percent. The invention of claim 13 further comprising, but not limited to, the polymer foam selected from the group consisting of polyurethane, polyester, polypropylene, nylon 6, nylon 6,6, nylon 12, nylon 6,12, polyethylene, terephthalate, polybutylene, polyphthalamide, polyoxymethylene, polycarbonate, and polyvinyl chloride. The invention of claim 13, wherein the polymer further comprises a thermoplastic polymer selected from, but not limited to, polyurethane, polyester, polypropylene, nylon 6, nylon 6,6, nylon 12, nylon 6,12, polyethylene, terephthalate, polybutylene, polyphthalamide, polyoxymethylene, polycarbonate, and polyvinyl chloride. The invention of claim 12, wherein the adsorbent further comprises a foam or felt incorporating any combination of graphene derivatives, lignocellulose, and charcoal. 1. An evaporative emissions control system for a motor vehicle for reducing evaporative emissions, comprising:
an evaporative canister coupled to a fuel tank, the canister being capable of adsorbing hydrocarbons and comprising an adsorbent selected from the group of activated graphene derivatives including but not limited to single layer graphene, few layer graphene, graphene oxide, reduced graphene oxide, and functionalized graphene;
a vapor inlet of the canister connected to the fuel tank;
a purge outlet of the canister connected to an air induction system;
the sorbent material is provided as a polymer foam, and either the foam or a felt outer layer expands into the canister to compress the sorbent material to maintain the internal volume of the canister and enable the sorption of the hydrocarbons;
the polymer foam is selected from, but not limited to, polyurethane, polyester, polypropylene, nylon 6, nylon 6,6, nylon 12, nylon 6,12, polyethylene, terephthalate, polybutylene, polyphthalamide, polyoxymethylene, polycarbonate, and polyvinyl chloride;
An evaporative emissions control system, wherein the adsorbent adsorbs fuel vapors when the engine is not operating and desorbs fuel vapors when the engine is operating.

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