The invention relates to a filler pipe for use in a vehicle. In particular it relates to a filler pipe for filling a vehicle tank with a compound, for instance an ammonia precursor.

A decomposition unit for ammonia precursor under the catalysis of a biol ogical catalyst, more particularly a urease enzyme, has been proposed in the international patent application WO2015032811 in the name of applicant. T he proposed decomposition unit is located inside the ammonia precursor tank. Such arrangement leads to a reduction of the internal working vol ume of the ammonia precursor tank. In addition, such arrangement is not convenient for the replacement of the biological catalyst.

In further investigations into such a system, the present inventors have come up with further improvements that enable that the decomposition unit does not reduce the working vol ume of the tank. These improvements also enable practical, rapid and secure replacement of the biological catalyst.

A ccordi ngly, accordi ng to a f i rst aspect, the i nventi on rel ates to a f i 11 er pi pe for f i 11 i ng a vehicle tank, the filler pipe having an inner surface and an outer surface, the inner surface defining an inner channel for conveying a compound therethrough. T he filler pipe is configured to retain a biological catalyst inside the inner channel. T he biological catalyst is adapted to convert the compound into reaction product. T he filler pipe is such that it comprises means for thermally conditioning the biological catalyst at at least one predetermined temperature range suitable for activation and/or preservation of the biological catalyst.

Thus, it is proposed a filler pipe with an integrated bio-chemical decomposition unit. Generally, the inner channel of the fil ler pipe is used for filling operation, for example for conveying a liquid to the tank, where it is stored. Generally, once the fil ling operation is performed the inner channel of the filler pipe is not used. The invention takes advantage of this available volume. One embodiment of the invention is based on the insight that the biological catalyst may be embedded and retained within the filler pipe and that the filler pipe may be equipped with thermal condition! ng means whi ch are configured to thermal ly activate and/or preserve the biological catalyst. According to the invention the catalysed conversion (i.e. decomposition of the compound) takes place inside the filler pipe. Thus, the filler pipe of the invention is a dual-function f i 11 er pi pe havi ng a standard f uncti on of f i 11 i ng/ref i 11 i ng a vehici e tank, and a f uncti on of converti ng a compound into reaction product

In a particular embodiment, the compound is an ammonia precursor, such as for instance urea. The ammonia precursor is suitably present as a composition, such as an aqueous composition, more particularly a concentrated aqueous composition. Suitably, the composition is a concentrated urea solution of at least 10% urea. In this embodiment, the reaction products may be for instance ammonia or hydrogen suitable for use in either selective catalytic reduction (SCR) methods for purifying exhaust gases or for fuelling fuel cells. Suitable biological catalysts are herein urease.

In an alternative embodiment, the compound is a hydrogen precursor, such as ammonia or saccharides (e.g. mono, di or polysaccharides). Good results are known for the enzymatic conversion of a disaccharide such as sucrose into hydrogen, for instance with enzymes such as invertase, glucose dehydrogenase (GDH), hydrogenase, and glucose isomerase (GI). T his may be highly useful to provide hydrogen for use in fuel cells.

The biological catalyses) used in the invention may be a composition either in liquid form or in sol id form.

The solid form may be a powder or a powder compressed into one or more pellets, granules or beads. Alternatively, it is in the form of capsules, pills or cartridges. Major advantages of cartridges appear that these may be provided in shape and dimensions that allow easy introduction inside the filler pipe, secure retention within the filler pipe and easy removal from the filler pipe. Moreover, cartridges may be provided with coatings to maintain integrity and also to avoid contamination of biological catalyst and/or its composition. In a particular embodiment, cartridges (and/or other solid forms) may further be provided with a liquid composition of biological catalyst inside.

T he sol id form may further comprise a hydrogel encapsulating the biological catalyst.

In a particular embodiment, use is made of a sol id substrate onto which the biological catalyst is immobilized. One example of a suitable solid substrate is for instance synthetic polymers such as polystyrene, EV OH, nylon-6 and the like. A lternatively, use may be made of carbohydrates, such as chitosan, dextran and agarose, and porous nanoparticles, for instance of silica.

Advantageously, the thermal conditioning means are attached to the inner surface of the filler pipe. T his arrangement allows a good control of the temperature of the biological catalyst. T he attachment of the thermal conditi oni ng means to the i nner surface of the f i 11 er pi pe may take place by welding, gluing, clipping, or other appropriate means, taking into account the material /structure of the filler pipe and the material /structure of the thermal conditioning means. In another particular embodiment the thermal conditioning means can be attached to the outer surface of the filler pipe. In yet another particular embodiment, the thermal conditioning means can be arranged between the i nner surface and outer surface of the f i 11 er pi pe. In this last embodi ment, the thermal conditioning means can be made of one piece with the filler pipe. For example, the filler pipe with its integrated thermal conditioning means can be injection moulded or blow moul ded or overmoul ded.

The thermal conditioning means may comprise e.g. a heater and/or a cooler. Suitably, the thermal conditioning means furthermore comprise a thermally insulating

encapsulation, such that the temperature in the inner channel of the filler pipe can be most easily kept within the desired temperature range independent of the outside temperature and/or the generation of heat upon use of the combustion engine.

Optionally, a cooler may be present, so as to lower the temperature in the inner channel of the filler pipe in case the environmental temperature woul d be higher.

The heater comprises, in a particular implementation, resistive heating elements, for instance in the form of metallic heating filaments (wires), flexible heaters (i.e. heaters comprising one or more resistive track(s) affixed to a f il m or placed between two fil ms), or any other type of resistive elements. PTC (positive temperature coefficient) elements are more particularly suitable for heating. Peltier effect cells constitute another example.

In a further embodiment heat may be transmitted to the fil ler pipe from heat sources within a vehicle, such as fuel cells, internal combustion engine, and exhaust line. Means for heat transmission are known per se and include, for instance, heat pipes, heat pumps, heat exchangers.

In one further embodiment the fil ler pipe can be provided with a temperature sensor and the thermal conditioning means can be controlled by control means on the basis of the sensed temperature. The control means are suitably configured, in one particular embodiment, to control the temperature in the inner channel of the filler pipe (where the biological catalyst(s) is retained) in a predetermined temperature range corresponding to preservation of the biological catalyses). In another parti cul ar embodi ment, the control means herei n control that the temperature i n the i nner channel of the f i 11 er pi pe remai ns above a mi ni mum temperature, for i nstance to prevent f reezi ng of the biological catalyst. In yet another particular embodiment, the control means herein control that the temperature in the inner channel of the filler pipe remains at a predetermined temperature range suitable for activation of the biological catalyses). T his temperature range is suitably 30-70eC, for i nstance from 40-60eC .

Advantageously, the filler pipe comprises an entry point for receiving at least one part of the compound from the vehicle tank and an exit point for draining the reaction product out of the filler pipe.

Thus, when decomposition is needed, a predetermined amount of compound is transferred by means of a transfer device from the vehicle tank into the inner channel of the fil ler pipe (where the biological catalyses) is retained) via the entry point. Once the decomposition is performed, the reaction product is evacuated (i.e. drained) out of the filler pipe via the exit point In a first particular embodiment, the exit point may be coupled to an exhaust gas line for selective catalytic reduction (SC R) of exhaust gases. In a second particular embodiment, the exit point may be coupled to a unit for conversion of the reaction product into hydrogen for fuell ing a hydrogen fuel cell. In a third particular embodiment the exit point may be coupled to a buffer tank. T he size of the buffer tank may be chosen in dependence on the specific application and the flow rate of reaction product. In a fourth particular embodiment, the exit point may be directly coupled to an ammonia fuel cell.

A transfer device can be for example a pump, valve, combination of both, gravity, gravity in combination with a valve or a valve in combination with whatever system known by the state of the art to transfer I i quid.

According to a further aspect the invention relates to a system, comprising a vehicle tank for the storage of a compound and a filler pipe as described above.

More particularly, the system of the invention is designed for mounting and use on board of a vehicle, including cars, trucks and motors, using either gasoline, diesel and optionally being a hybrid type that can also be driven on fuel cells.

According to a further aspect the invention relates to a method of operating the above- mentioned system, comprising the steps of:

addi ng a compound i nto the vehi cl e tank vi a the f i 11 er pi pe;

- addi ng a bi ol ogi cal catalyst i n the f i 11 er pi pe and retai ni ng the bi ol ogi cal catalyst i nsi de of the filler pipe;

conveying (i.e. transferring) at least one part of the compound from the vehicle tank to the filler pipe;

converting said at least one part of the compound in the filler pipe under catalysis of the biological catalyst into reaction product

According to a further aspect the invention relates to a vehicle equipped with the above- mentioned system.

The present invention is illustrated in a non limitative way by the examples below relying on figures 1 to 9 attached. In these figures, identical or similar devices bear identical reference numbers.

T he i nventi on i s i 11 ustrated i n the f i gures 1 -9 herei nafter i n rel ati on to embodi ments, wherei n the f i 11 er pi pe i s used for f i 11 i ng/ref i 11 i ng an ammoni a precursor tank of a vehi cl e.

This ammonia precursor is for example an urea solution, more particularly a concentrated urea solution of at least 25 wt% urea, more preferably a urea solution of around 32.5 wt% urea. T he term ^" urea sol uti on_ is understood i n the context of the present i nventi on, to mean any, generally aqueous, solution containing urea. T he invention gives particularly good results with eutectic water/urea solutions for which there is a quality standard; for example, according to the standard ISO 22241, in the case of the AdBlue ^÷ solution (a commercial solution of urea), the urea content is between 31.8% and 33.2% (by weight), hence an available amount of ammonia between 18.0% and 18.8%. While the invention is illustrated hereinafter with reference to the conversion of urea solution, this is merely a specific example. Of course, the invention may also be appl ied to other compounds on board of a vehicle that need conversion, such as the conversion of ammonia and/or other hydrogen precursors into hydrogen for fuel cells.

Figure 1 is a schematic view of a system according to a first particular embodiment of the present invention.

As ill ustrated in the example of Figure 1, the system comprises:

a contai ner (i.e. tank) [ 1 ] f or the storage of an aqueous urea sol uti on, for exampl e AdBlue÷ solution (commercial sol ution of urea); and

- a filler pipe [2] in communication with the tank [1].

In the example of Figure 1, the filler pipe [2] is a hoi low tube. T he filler pipe [2] has an inlet port [21] through which urea solution can be introduced. Once it is introduced the urea solution exits an outlet port [22] to flow inside the tank [1].

The inlet port [21] is further adapted to allow introduction of a biological catalyst within the filler pipe. The biological catalyst is adapted to convert urea solution into, for example, ammonia or aqua ammonia (i.e. reaction product). For example, an enzyme, such as urease, can be used to decompose the urea sol ution. Of course, other suitable protein sequence can be used. In the context of the present application, the term ^" aqua ammonia _, is to mean a mixture of effluents resulting from the decomposition of an ammonia precursor. This mixture of effluents may contain ammonium hydroxide (a fraction of which is ionized), residue of ammonia precursor (i.e. part of the ammonia precursor that has not been decomposed) and eventually other products (such as ammonium carbonate and/or ammonium sesqui-carbonate and/or ammonium bicarbonate).

In the example of Figure 1, the inlet port [21] is dimensioned such that a cartridge containing a biological catalyst [3] can be introduced in the filler pipe. For example, the cartridge can have a storage vol ume ranging from 10 ml up to 1000 ml, or preferably from 50 ml to 600 ml, or more preferably volumes ranging from 100 ml up to 200 ml.

As ill ustrated in Figure 1, the outlet port [22] of the filler pipe comprises a perforated element or a perforated portion [23] such as a grid (or a net). T he grid prevents the cartridge to fal I inside the tank [1]. T he grid comprises a plurality of through-holes (not shown), each through-hole being arranged and sized such that the biological catalyst is retained within the filler pipe and such that the urea solution passes through in the tank [1].

In a particular embodiment, the grid is attached (welded, glued,u ) to the outlet port [22] of the filler pipe. In another particular embodiment, the filler pipe [2] can be made by injection moulding and integrate (as moulded in one piece with it) the grid. Advantageously, the through- hoi es are further sized so as to al I ow a predetermi ned ref i 11 i ng f I ow rate and to reduce spitback effect during the refilling operation. T he grid can also be combined with a conventional anti- spitback mechanism such as a flapper.

The filler pipe [2] further comprises thermal conditioning means [24] which are configured to thermally activate and/or preserve the biological catalyst retained within the filler pipe. In the example of Figure 1, the thermal conditioning means [24] are attached around the inner surface of the filler pipe. For example, the thermal conditioning means [24] can comprise a heater and one or more further thermally conditioning elements such as a resistive heater, Peltier effect cel ls, insulating elements, phase change materials. T he heater can be provided in the form of a flexible wi re. T hi s has the advantage that the heat may be distri buted wi thi n the i nteri or of the f i 11 er pi pe. The at least one further thermally conditioning elements can be one or more layers of thermally insulating material.

The filler pipe [2] further comprises an entry point [25] for receiving a predetermined amount of urea solution from the tank [1]. The filler pipe [2] also comprises an exit point [26] for draining the reaction product (obtained after conversion of the urea solution) out of the filler pipe.

In the example of Figure 1, the system comprises a pump [4] arranged inside the tank [1].

The pump [4] is connected to a suction point located inside the tank [1]. The pump [4] is configured to transport the urea solution from the tank to the entry point [25] of the filler pipe, via a fluid line [27].

When decomposition is needed, a predetermined amount of urea sol ution is transferred by the pump [4] from the tank [1] to the entry point [25] of the filler pipe. Therewith, contact is established between the urea solution and the biological catalyst retained within the filler pipe. T hen, the thermal conditi oni ng means [24] are activated such that the temperature withi n the f i 11 er pi pe can be hel d at or can be brought to a predef i ned temperature withi n a temperature range suitable for activation of the biological catalyst. T hus, the predetermined amount of urea solution is converted i nto a reaction product, for exampl e aqua ammonia. T he progress of the conversion is suitably controlled by a time-control device or by a chemical sensor. A time-control device can be a clock or any timing mechanism driven by a motor, by the vehicle electronic system or by another mean known by the status of the art. A chemical sensor device can be for example a pH sensor or an ammonia sensor. Alternatively, a physical sensor can be used.

Once the decomposition is performed, the reaction product is evacuated (i.e. drained) out of the filler pipe via the exit point [26]. For example, when the conversion has reached a predefined conversion degree, for instance when 50% or more of the ammonia precursor is converted into ammonia solution, or ideally when at least 80 % or more of the ammonia precursor is converted into aqua ammonia, the resulting effluents (i.e. reaction product) are then transferred to a buffer tank [5] by a transfer devi ce ( not shown), via a f I ui d I i ne [28] . T he conversi on may continue in this buffer tank (if necessary the effluents of buffer tank may be transferred back to the f i 11 er pi pe for further conversion).

In the example of Figure 1, the buffer tank [5] is arranged within the tank [1]. In another embodiment the buffer tank [5] may be arranged outside the tank [1]. As illustrated in Figure 1, one portion of the fl uid line [28] is arranged outside the filler pipe and the tank. In another embodi ment; the f I ui d I i ne [28] may be total ly arranged i nsi de the f i 11 er pi pe and/or the tank.

The reaction product stored in the buffer tank [5] can be used in either a selective catalytic reduction (SC R) system for purifying exhaust gases or for fuelling fuel cells operating on the basis of ammonia or hydrogen. The reaction product may be transferred to such system by means of a transfer device (not shown), for example a pump.

Figure 2 is a schematic view of a system according to a second particular embodiment of the present invention.

The example of the Figure 2 is a particular embodiment of the embodiment described in Figure 1. It differs from the embodiment of Figure 1 in that the decomposition is performed in a continuous mode. When decomposition is needed, some urea solution is transferred by a fluid transfer device [4~ from the tank [1] to the entry point [25] of the fil ler pipe [2]. The fl uid transfer device [4^ ensures the continuous flow of urea solution through the filler pipe [2]. T herewith, contact is established between the urea solution and the biological catalyst retained within the filler pipe [2]. T hen, the thermal conditioning means [24] are activated such that the temperature within the f i 11 er pi pe can be hel d at or can be brought to a predef i ned temperature withi n a temperature range suitable for activation of the biological catalyst. The conversion is performed in a continuous mode at an ammonia precursor solution flow rate and residence time ideal to achieve the complete conversion, for instance, to achieve 50% of ammonia precursor conversion into ammonia solution, or ideally at least 80 % or more of ammonia precursor a conversion into aqua ammonia. T he residence time corresponds to the time that, at a constant flow rate of ammonia precursor solution, a particle of ammonia precursor solution needs to be completely converted into ammonia solution from the entry poi nt [25] to an exit poi nt [26] of the f i 11 er pi pe [2] . T he resulti ng eff I uents (i.e. reaction product) are continuously transferred to the Buffer tank [5] by a fluid transfer device (not drawn) or by gravity through the effluents pipe. Whenever the vehicle is stopped, the biological catalyst can stil I continue with the chemical conversion reaction during a certain period of time (say 2 hours), due to the thermal properties of the decomposition unit material within the fil ler pipe. When the conversion has to be restarted, the fl uid transfer device [4^ is activated so as to send urea solution through the filler pipe [2]. The progress of the conversion is controlled by a time-control device or by a chemical sensor. A time-control device can be a clock or any timing mechanism driven by a motor, by the vehicle electronic system or by another mean known by the state of the art. A chemical sensor device can be for example a pH sensor, an ammonia sensor or whatever sensor known by the state of the art. T he converted effl uents are stored in Buffer tank [5]. T he sol ution i n the buffer tank is ready to be sent by second fl uid transfer device to a downstream tank, to the exhaust pipe or to any additional system that stores or consumes ammonia (not drawn).

Figure 3 is a schematic view of a system according to a third particular embodiment of the present i nvention.

T he example of Figure 3 differs from the example of Figure 1 in that the fill er pipe [6] of Figure 3 has an external portion [61] extending outside of the tank [1] and an internal portion [62] extending inside of the tank [1] . T he internal portion [62] provides an additional storage volume for stori ng the bi ol ogi cal catalyst. T hus, the storage vol ume of the bi ol ogi cal catalyst can be i ncreased without i ncreasi ng the external f ootpri nt of the system. A ccordi ngly, a greater amount of reaction product can be generated.

Figure 4 is a schematic view of a system according to a fourth particular embodiment of the present i nvention.

T he example of Figure 4 differs from the example of Figure 1 in that the fill er pipe [7] of Figure 4 has a first channel [71] which is configured for conveying urea sol ution to the tank [1] and a second distinct channel [72] for the storage of the biological catalyst. T his arrangement al lows to increase the l ifetime of the biological catalyst Indeed, the biological catalyst is not in contact with the urea sol ution during the refil ling operation. In other words, the biological catalyst is separated from the urea sol ution, when the decomposition of the urea solution is not desired. It also allows refi ll ing without necessarily removing the biological catalyst from the filler pipe. As ill ustrated, the thermal conditioning means [24] are attached around the inner surface of the second channel. In this example, the second channel [72] is a slightly bend hol low tube.

Figure 5 is a schematic view of a system according to a fifth particular embodiment of the present i nvention.

T he example of Figure 5 differs from the example of Figure 4 in that the second channel

[73] is a curved (or a serpentine shape) hollow tube.

It is to note that Figures 1 to 5 are schematic views and for reason of clarity al l components of the system are not represented.

Figure 6 is a schematic view of a system according to a sixth particular embodiment of the present i nvention.

T he example of Figure 6 differs from the example of Figure 1 in that the tank comprises an intermediate buffer tank [5^. At key-off of the vehicle, the resulting effl uent (i.e. reaction product) not entirely converted is transferred to the intermediate buffer tank [5~ via the fl uid l i ne [27]. T he completion of the conversion is performed at key-on of the vehicle by transferring back the reacti on product to the f i 11 er pi pe. T he f I ui d transfer i s control I ed by two valves [V 1 , V 2] . At key- on of the vehicle, the valve [V 2] is opened and the valve [V 1] is closed when the conversion is required. Conversely, the valve [V 1] is opened and the valve [V2] is closed when the intermediate buffer tank is empty and the conversion is required.

In another embodiment valves [V 1] and [V 2] are replaced by a three ways valve.

Systems illustrated in Figures 1 to 6 can comprise other components, for example check valves, level sensors, quality sensors or buffers.

Figure 7 is a schematic view of a cartridge [31] for the storage of biological catalyst according to a particular embodi ment. T he cartridge walls can be made out of flexible polymeric material, forming a cylindrical tube with top and bottom connectors that allow the urea solution to enter and exit the cartridge while keeping the biological catalyst trapped inside. Due to its flexible nature, the cartri dge can be easi ly i ntroduced through the f i 11 er pi pe j ust by gently pushi ng it down. After a period of time corresponding to the duration of the activity of the biological catalyst, the cartridge can be easily removed from the filler pipe by pulling it up.

Figure 8 is a schematic view of a cartridge [32] for the storage of biological catalyst according to an alternative embodiment In this alternative embodiment, the cartridge comprises a plurality of cylinders [33] (i.e. storage units) which are linked to each other by flexible connectors [34]. This design allows a high degree of flexibility and adaptability of the cartridge to different shapes of filler pipes.

In a particular embodiment the cartridge for the storage of the biological catalyst [3] is attached to a tank cap, so that when the tank cap is removed to fill the tank with urea solution, the cartri dge comes out too; the I i nk between the tank cap and the cartri dge is designed so as to al I ow the tank cap to rotate al ong the threaded whi I e the cartri dge si i des al ong the f i 11 er pi pe.

Figure 9 is a schematic view of cartridge [35] for the storage of biological catalyst according to another alternative embodiment In this other alternative embodiment the cartridge [33] is designed as cylinder with a hollow cavity such that it surrounds the fil ler pipe [8]. Thus, it is not requi red to remove the cartri dge to f i 11 the urea sol uti on tank.

Whilst the principles of the invention have been set out above in connection with specific embodiments, it is to be understood that this description is merely made by way of example and not as a limitation of the scope of protection which is determined by the appended claims.