Patent Application
20220349525
This disclosure relates generally to a method for providing hydrogen to mobile vehicles such as trucks and cars for Carbon-Neutral Hydrogen (CNH) operation when a liquid organic hydrogen carrier is used. In an electric or motor vehicle, hydrogen may be combusted to provide energy, or the hydrogen may be fed to a fuel cell to generate electricity to power the vehicle. This disclosure includes a process for supplying hydrogen, carried in the form of fresh LOHC (Liquid Organic Hydrogen Carrier). The fresh LOHC may be subject to a catalytic dehydrogenation reaction to release the hydrogen for use. Alternatively, the fresh LOHC may be used as a liquid fuel for direct combustion, replacing traditional gasoline and diesel fuels. A by-product being a hydrogen-depleted or dehydrogenated organic carrier is also produced, referred to here as “spent” LOHC. The spent LOHC is stored on-board for recycle and rehydrogenation to make “fresh” LOHC for re-use, being hydrogen-enriched or hydrogenated to restore its labile hydrogen content.
More specifically, this disclosure relates to apparatus, methods and technologies to supply a mobile vehicle with fresh LOHC from a modular fueling station. The disclosure also relates to methods of returning spent LOHC to the fueling station from the mobile vehicle. The disclosure also relates to the methods of resupplying the fueling station with fresh LOHC from an LOHC tanker truck. The disclosure also relates to refilling the tanker truck with spent LOHC for return to a site for re-hydrogenation and re-use. The disclosure also relates to the conversion of conventional fueling stations, both gasoline and diesel, for use as LOHC fueling stations. The disclosure also relates to a fueling station configured in modular units and associated methods and processes that enable the separate and simultaneous storage, handling, dispensing and reception of fresh and spent LOHC fuels wherein the modular fueling station is operated in a manner to ensure an overall carbon-neutral environmental footprint by managing and controlling against the release of fuel and fuel vapors to the atmosphere.
Systems employing battery storage to supply electricity for transportation needs are known and readily available. But large energy consumers such as long-haul trucks, trains and heavy earth-moving and other heavy-duty equipment that depend exclusively on batteries are limited in range, in operating capacity and in time by battery capacity, even though typically being in the kilowatt per hour (kWh) range and extended battery recharging time required. United States patent application publication No.: 2022/0109175A1 (“Allinson et al.”) discloses a method for powering vehicles and equipment for extended periods in a carbon-neutral process, utilizing an energy transfer system that can store power in the megawatt per hour (MWh) range which can be replenished in minutes thereby greatly extending the equipment's performance envelopes.
The method of Allinson et al. uses liquid organic hydrogen carriers or LOHC to supply hydrogen for on-board use. Many different molecules have been used or studied as LOHC materials, including such saturated cyclic compounds such as methylcyclohexane or dibenzyl toluene. Stated briefly, hydrogen is extracted from the LOHC in a catalytic dehydrogenation reaction. The hydrogen is then used as a fuel, or delivered to a fuel cell, such as a PEMFC (proton exchange membrane fuel cell) or SOFC (solid oxide fuel cell), where it is used to generate electricity to power an electric vehicle or hybrid electric vehicle. The spent LOHC is returned to a storage tank, ultimately for recycle, re-hydrogenation, and reuse.
The LOHC can be delivered, stored, and dispensed using existing equipment common to oil refineries, petrochemical plants, and current distribution pipelines to terminals.
Systems utilizing fuel cells for the generation of power are known and readily available, but they cannot currently operate in carbon-neutral (CN) mode utilizing LOHCs without a CN external power or heat supply.
Carbon-neutral systems utilizing hydrogen are known and readily available but generally require high pressure compression in the 10,000-psig region for storage and use in fuel cells.
This disclosure relates to the use of fueling stations to deliver LOHC to trucks and cars. The disclosure also relates to the methods of resupplying the fueling station with fresh LOHC. The disclosure also relates to the method and apparatus for conversion of conventional fueling stations, both gasoline and diesel, for use as LOHC fueling stations.
Allinson et al. further teaches the use of Carbon Neutral electricity generation to power electric vehicles.
What is needed, are apparatus, methods and technologies that enable the convenient dispensing of fresh LOHC and recovery of spent LOHC in a manner accessible to mobile vehicles comparable to existing fueling stations. One embodiment of the present disclosure is a Carbon Neutral Power Module (CNPM) that operates to supply electrical energy used by mobile devices. One embodiment of the CNPM comprises a first storage vessel for containing the recyclable LOHC prior to dehydrogenation, a second storage vessel for containing the unloaded aromatic substrate product, or spent LOHC, from dehydrogenation, a dehydrogenation reaction zone for generating hydrogen from recyclable R-LOHC, a hydrogen purification capability for preparing the hydrogen for electrochemical conversion and electricity generation, and a separation unit for separating unloaded aromatic substrate from dehydrogenation into a recycle liquid.
In another embodiment of the present disclosure, the CNPM includes two liquid storage vessels, a first storage vessel for containing the LOHC as delivered to the vehicle and a second storage vessel for receiving and containing the recycle liquid recovered from dehydrogenation termed spent LOHC. The recyclable R-LOHC and the spent LOHC are low vapor pressure liquids that may be stored in vessels that would be suitable for gasoline, kerosene, and diesel fuel storage, further including such existing vessels modified by the apparatus, methods and technology according to the present disclosure. In one embodiment, the first and the second storage vessels are independent of one another, or alternatively different vessels located separately in the vehicle. In another embodiment, the two storage vessels are combined into a single vessel, separated into two volumes within the storage vessel by a flexible bladder or a similar means that enables access to both the vapor space and liquid storage space of a single integrated vessel. In related embodiments, as LOHC is supplied to the vehicle and the recycle liquid spent LOHC is removed, the relative size of a first volume containing the LOHC decreases and that of a second volume containing the spent liquid spent LOHC increases. In a further related embodiment, a novel dual nozzle apparatus as disclosed herein may dispense fresh R-LOHC to the vehicle while simultaneously extracting spent liquid LOHC from the vehicle.
The present disclosure further relates to apparatus, methods and technology to supply the vehicle with LOHC by way of a fueling station. The present disclosure also relates to the methods of returning spent LOHC to the fueling station recovered from a vehicle. The present disclosure also relates to the methods of resupplying the fueling station with fresh LOHC from an LOHC tanker truck. The present disclosure also relates to refilling a tanker truck with spent LOHC for return to an originating site for re-hydrogenation and re-use. The present disclosure also relates to the conversion of conventional fueling stations, both gasoline and diesel, for use as LOHC fueling stations.
It may be mentioned that handling an LOHC, such as methylcyclohexane, is in some ways less problematic than handling gasoline. LOHC, unlike gasoline, does not include MTBE, ethanol, or other water soluble or partially soluble materials. Therefore, a spill is less of a threat to groundwater. Further, LOHC does not include highly volatile components, such as ethanol or pentane, which makes it more difficult to recover all associated vapors when handling a liquid fuel.
General embodiments of the present disclosure discussed herein include a fueling station for transferring Liquid Organic Hydrogen Carrier (LOHC) fuels to and from a mobile vehicle that has a fresh LOHC module consisting of: (i) a fresh LOHC storage tank; (ii) a first submersible pump within the fresh LOHC storage tank; (iii) a delivery conduit connecting the fresh LOHC storage tank and the first submersible pump capable of transferring fresh LOHC fuel from the fresh LOHC storage tank to a fuel dispenser during a first transfer operation; (iv) a fuel dispenser capable of transferring the fresh LOHC fuel to a mobile vehicle; (v) a vapor recovery system including a vapor vent conduit connected to a vapor vent located in the headspace of the fresh LOHC storage tank and the fuel dispenser for collecting fuel vapors released during the first transfer operation; and a spent LOHC module consisting of: (vi) a spent LOHC storage tank; (vii) a second submersible pump within the spent LOHC storage tank; (viii) a receiving conduit connecting the spent LOHC storage tank and the second submersible pump capable of transferring spent LOHC fuel from the mobile vehicle in a second transfer operation; and (ix) a vapor vent conduit connected to a vapor vent located in the headspace of the spent LOHC storage tank for collecting fuel vapors from the headspace of the spent LOHC storage tank during the second transfer operation.
In further embodiments, the fueling station may further be configured so that the fresh and spent LOHC modules are operated in a reverse manner to transfer in a first operation the fresh LOHC fuel from the fuel dispenser from a mobile vehicle to the fresh LOHC storage tank and independently in a second operation transfer the spent LOHC fuel to the fuel dispenser to a mobile vehicle; wherein the mobile vehicle has an onboard storage tank receptive to either the fresh or spent LOHC fuel.
In yet further embodiments, the fueling station includes a vapor condenser connected to a vapor recovery system for condensing LOHC fuel vapor to the corresponding condensed liquid LOHC fuel form of the LOHC fuel and returning the condensed liquid LOHC fuel to the corresponding LOHC storage tank to maintain an overall carbon-neutral transfer process by means of one or more liquid conduits associated with the vapor recovery system, and in alternative embodiments, the fueling may further include a flow controller and counter for controlling and measuring a volume of a LOHC fuel transferred to or transferred from the mobile vehicle.
In related embodiments, the vapor recovery system further comprises a vapor condenser for condensing LOHC fuel vapors vented from either LOHC storage tank configured to return the corresponding condensed liquid LOHC fuel to a LOHC storage tank.
Another embodiment contemplates an LOHC fueling station wherein a conventional gasoline or diesel fueling station has been converted to the handling of LOHC fuels by substituting one or more existing fuel storage tanks with either a fresh LOHC module or a spent LOHC module or both, and at least one vapor recovery system.
In some embodiments, the fuel station further includes an air or compressed gas inlet connected to at least one of the LOHC storage tanks; wherein air or compressed gas introduced to the gas inlet operates to maintain vapor pressure balance with the LOHC storage tank during a transfer of a liquid LOHC fuel to the corresponding LOHC storage tank; and wherein the vapor pressure operates to maintain a net carbon-neutral transfer process by means of a pressure-vacuum relief valve communicating with the air or compressed gas inlet.
In some embodiments, the fueling station accommodates mobile vehicles having a single onboard storage tank; wherein the onboard storage tank is configured to receive, store and dispense a LOHC fuel; wherein the onboard storage tank further hosts a vapor recovery system onboard the mobile vehicle that operates to balance the vapor pressure between the onboard storage tank and an external storage tank during a transfer operation of the LOHC fuel so as to prevent the release of fuel vapors to the environment in order to maintain an overall carbon-neutral process.
In other embodiments, the fueling station accommodates mobile vehicles having a first and second onboard storage tank; wherein the first onboard storage tank is configured to receive, store and dispense spent LOHC fuel; and wherein the second onboard storage tank is configured to receive, store and dispense fresh LOHC fuel.
In other embodiments, the mobile vehicle has an onboard vapor recovery system that operates to balance the vapor pressure between the first and second onboard storage tanks during a transfer operation so as to prevent the release of fuel vapors to the environment in order to maintain an overall carbon-neutral process.
In yet further embodiments, the mobile vehicle has an onboard storage tank configured to have: (i) an internal spent LOHC portion receptive to receive, store and dispense spent LOHC fuel; (ii) a fresh LOHC portion receptive to receive, store and dispense fresh LOHC fuel; and (iii) a partition system configured to separate the onboard storage tank into the internal spent and fresh LOHC portions; wherein the partition system is selected from a movable baffle, flexible baffle, moving piston, one of more flexible bladders configured with according means to enabling expansion and contraction in volume, and combinations thereof; and wherein the partition system maintains an overall constant volume while internally enabling the respective the spent LOHC portion and fresh LOHC portion to change volumes with respect to one another based on the volume of spent LOHC fuel and the volume of fresh LOHC fuel present within the onboard storage tank at any given time.
Further embodiments of the present disclosure include methods and processes for operating a LOHC fueling station for transferring LOHC fuel to and from a mobile vehicle in communication with the fueling station; wherein the transfer of the LOHC fuel is conducted in an overall carbon-neutral manner that prevents the release of any corresponding LOHC fuel vapors to the environment.
Embodied methods include the use of apparatus such as the disclosed vapor recovery system hosting a vapor condenser connected to the vapor recovery system for condensing LOHC fuel vapor to the corresponding condensed liquid LOHC fuel form of the LOHC fuel and returning the condensed liquid LOHC fuel to the corresponding LOHC storage tank to maintain an overall carbon-neutral transfer process by means of one or more liquid conduits associated with the vapor recovery system.
Embodied methods further include the use of the vapor recovery system further including an air or compressed gas inlet connected to at least one of the LOHC storage tanks; wherein air or compressed gas introduced to the gas inlet operates to maintain vapor pressure balance with the LOHC storage tank during a transfer of a liquid LOHC fuel to the corresponding LOHC storage tank; and wherein the vapor pressure operates to maintain a net carbon-neutral transfer process by means of a pressure-vacuum relief valve communicating with the air or compressed gas inlet.
Further embodied methods include using mobile vehicles hosting a vapor recovery system onboard the mobile vehicle that operates to balance the vapor pressure between the first and second onboard storage tanks during a transfer operation so as to prevent the release of fuel vapors to the environment in order to maintain an overall carbon-neutral process.
Methods include embodiments wherein the mobile vehicle has a first and second onboard storage tank; wherein the first onboard storage tank is configured to receive, store and dispense spent LOHC fuel; and wherein the second onboard storage tank is configured to receive, store and dispense fresh LOHC fuel, as well as wherein the mobile vehicle has an onboard storage tank configured to have: (i) an internal spent LOHC portion receptive to receive, store and dispense spent LOHC fuel; (ii) a fresh LOHC portion receptive to receive, store and dispense fresh LOHC fuel; and (iii) a partition system configured to separate the onboard storage tank into the internal spent and fresh LOHC portions; wherein the partition system is selected from a movable baffle, flexible baffle, moving piston, one of more flexible bladders configured with according means to enabling expansion and contraction in volume, and combinations thereof; and wherein the partition system maintains an overall constant volume while internally enabling the respective the spent LOHC portion and fresh LOHC portion to change volumes with respect to one another based on the volume of spent LOHC fuel and the volume of fresh LOHC fuel present within the onboard storage tank at any given time.
Described below are more detailed embodiments of processes and systems to deliver fresh or regenerated LOHC to a vehicle for the purpose of on-board generation of hydrogen, which, in turn may be used to generate electricity by use of a hydrogen fuel cell. Various embodiments of the disclosed processes and systems would also be used to simultaneously recover spent LOHC that has previously been used to release hydrogen. Further embodiments of this present disclosure may incorporate other related LOHC systems well known in the art, as well as a range of common hydrogenated refinery streams that may also be adapted for use as LOHC hydrogen carriers, but employing the further novel features of the present disclosure. Spent LOHC is a dehydrogenated form of the starting material, such as for example, but not limited to methylcyclohexane (MCH) as one suitable LOHC fuel material, the resulting spent LOHC being toluene which is the dehydrogenation product of MCH after extraction of hydrogen.
The modular LOHC fueling station includes an LOHC storage tank 100 for LOHC fuel storage. The LOHC storage tank 100 may in one embodiment be an elevated tank above grade, or alternatively as shown, located below the grade, or yet alternatively positioned on the grade. In one embodiment, liquid LOHC fuel is delivered by fuel supply pump 120 via a fuel supply conduit 118, through a containment chamber 122, through a fuel delivery conduit 128 and then through a dispenser 124 for delivery to a vehicle 134 via a fueling hose 130. In one embodiment, the fueling hose 130 is a coaxial hose that includes a first coaxial conduit 131 (not shown) for delivering fresh LOHC via a delivery nozzle 133 (not shown) to the vehicle 134 and a second coaxial conduit 132 (not shown) positioned coaxially with regard to the first coaxial conduit within the fueling hose 130 for conducting vapors via the delivery nozzle 133 from a fuel tank in the vehicle 134 to the dispenser 124.
As the fuel tank (not shown) in the vehicle 134 is filled, vapor in the headspace of the fuel tank is displaced. In one embodiment, this displaced vapor is removed via the second coaxial conduit 132 in the fueling hose 130 and returned to a vapor return module 110 located with LOHC storage tank 100 via vapor return conduit 108 with the aid of a vacuum-assist pump 116 located in the dispenser 124. In a related embodiment, fuel vapor in the LOHC storage tank 100 is vented from vapor vent module 112 through a vapor vent conduit 114 and captured in a vapor trap 126 to prevent release to the environment in support of maintaining a carbon-neutral fuel handling process according to the present disclosure. In general embodiments, the vapor handling apparatus are collectively described herein as a vapor recovery system consisting of the disclosed vapor conduits, vapor vents, vapor collection and vapor return modules, connecting conduits for both liquid and vapor forms of the LOHC fuels, control valves, and the like, and further including vapor condensers operating to convert gaseous fuel vapors to their corresponding liquid fuel forms.
In a related embodiment, the fueling hose 130 features two parallel internal conduits that serve a similar function to the coaxial conduits previously described, one of the parallel conduits configured for conveying an LOHC liquid fuel and the second parallel conduit configured to convey any displaced vapor or vapor released from the liquid LOHC fuel or vapor present in the headspace of a liquid LOHC supply tank, fuel tank, storage tank or the like.
In another example embodiment as illustrated in
In alternative embodiments wherein a tanker truck delivering fresh LOHC features only a single onboard tank, the fresh LOHC is delivered in a first step to an appropriate storage tank and the empty tanker truck is then refilled with spent LOHC in a second step. In an alternate embodiment, it is also possible to use a tanker truck featuring a second onboard tank, with a first tank containing fresh LOHC and the second tank initially being empty so as to provide a means to retrieve spent LOHC for recovery and regeneration of fresh LOHC. In related embodiments, the headspace volumes of the first and second tanks are in communication with one another either directly, or connected by means of a passive pressure equalization value, or gas pump or the like with a pressure sensing means to measure vapor pressures in the tanks or differential vapor pressures between the onboard tanks so as to enable the gas pump to adjust or equalize vapor pressures between the two onboard tanks. In further closely related embodiments, a communication means such as described herein above is further employed to control vapors and to sense and adjust fuel vapor pressures between the one or more onboard tanks and either a receiving tank or a supply tank holding or receptive to either fresh or spent LOHC fuel during a transfer process between a mobile vehicle or tanker truck and the LOHC refueling station according to the present disclosure.
In embodiments featuring tanker trucks with two onboard tanks, the two steps of delivery and recovery as described herein can then be done simultaneously while the tanker truck is located and communicating with the LOHC fuel handling facility as disclosed. In further embodiments, it is also possible to use a modified tanker truck with a single tank that alternatively features a movable partition that moves in response to the relative amount of spent and fresh LOHC present therein. In one example embodiment featuring a movable barrier or partition means, fresh LOHC is drained from the tanker truck from the space located on one side of the partition while spent LOHC is filled into the same tank into space located on the other side of the partition. In further embodiments, the partition system or moveable partition means includes, but is not limited to a movable baffle, flexible baffle, moving piston, one of more flexible bladders configured with according means to enabling expansion and contraction in volume, and combinations thereof capable of adjusting the relative volumes of two independent partition volumes within a tank to hold and separate two different liquids from one another without cross-mixing and further capable of adjusting the relative volumes of each of the two different liquids in response to either one of the liquids being added to or removed from its respective portion of the storage tank during a transfer operation.
With a movable partition or similar partitioning means present within a single onboard tank, filling of one external storage tank while emptying a second external storage tank can occur simultaneously, and in related alternative embodiments, filling of one fuel station receiving tank while dispensing from a second fuel station supply tank can also occur simultaneously, significantly reducing the amount of time necessary to fill, swap or supply a desired volume of spent and fresh LOHC liquids between a mobile vehicle and tanker truck. In related embodiments, the vapor pressure in the tanks can be monitored and controlled by means of the various apparatus, valves, pumps and vapor communication and collection means as disclosed herein to maintain either a desired pressure differential to help transfer the liquid fuel or an equilibrium in pressures balanced to prevent vapor lock or excessive pressure buildup that would otherwise require the unwanted venting of fuel vapors to the atmosphere.
Movement of the partition 404 as it moves to accommodate the increased volume of spent LOHC or the decreased volume of fresh LOHC, or in embodiments in which the process is reversed, does not create fuel vapors as happens in a conventional fuel tank which is rigid and therefor results in the creation of a headspace within the tank that fills with fuel vapors. Although use of a single tank with a movable partition has multiple advantages in reducing weight and volume, and the need for onboard or external vapor pressure control of the onboard tank itself, control of fuel vapors in these alternate embodiments requires control of the fuel vapors in the supply and recovery tanks located at the fueling station.
Thus, a means to monitor, control, recover and recycle fuel vapors present in the supply and receiving tanks holding fresh and spent LOHC liquid fuels is required, particularly with a means to prevent any release of the fuel vapors from the LOHC transfer station so that the transfer process can be maintained under rigid carbon-neutral conditions that maintain environmental integrity.
Accordingly, in one embodiment as illustrated in
In further embodiments illustrated in
In related embodiments, either or both of the fresh LOHC delivery conduit 428 and removal conduit 442 may include an in line flow controller and counter unit 426 (not shown) to measure and control the volume of fresh and spent LOHC fuel being transferred, and in alternative embodiments, the volumes compared so that any discrepancy in volumes accounted for in order to detect unwanted leaks that would otherwise compromise the net carbon-neutral transfer of LOHC fuels during a transfer operation between a mobile vehicle, tanker truck and the LOHC transfer station according to the various embodiments of the disclosure as described and illustrated in the figures.
This application claims the benefit of the priority of an earlier filed U.S. provisional patent application Ser. No. 63/181,968, entitled “Fueling Station For Supply of Liquid Organic Hydrogen Carriers and Method of Operation,” filed on Apr. 30, 2021, which is hereby incorporated in its entirety by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 63181968 | Apr 2021 | US |
