TECHNICAL FIELD
. [0001] The present subject matter relates generally to internal combustion engines and. more particularly, but not exclusively, to a control system for on-board hydrogen generation and a method thereof.
BACKGROUND
[0002] Generally, internal combustion engines utilize non-renewable source of energy in the form of gasoline and diesel as fuel to provide power for achieving the desired motion. Other known sources, especially some of the renewable source of energy for providing power to the internal combustion engines include bio-fuel, electricity, solar energy, and so on. Recently, there has been a huge global demand for fuel obtained from the non-renewable sources that has substantially raised the cost of crude oil. There are also other notable concerns towards meeting the stringent emission norms for internal combustion engines operated on such fuels. This has lead to the utilization of alternative fuel sources for powering internal combustion engines.
[0003] Recently, hydrogen is being widely used as an alternative fuel for powering internal combustion engines. Several research initiatives have been undertaken for effectively utilizing hydrogen as an alternative fuel both as an auxiliary fuel to engines powered by gasoline and diesel, and as an independent fuel powering internal combustion engines run only on hydrogen. Hydrogen as an alternative fuel could prove to act as an effective addendum to currently used non¬renewable sources due to its high combustion efficiency at the same time could act as an environment friendly fuel on account of its low emission capability.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference like features and components.

[0005] FIG. 1(a) illustrates an internal combustion (IC) engine, in accordance
with an embodiment of the present subject matter.
[0006] FIG. 2 (a) illustrates a control system of on-board hydrogen generation,
in accordance with an embodiment of the present subject matter.
[0007] FIG. 2 (b) illustrates a control system of on-board hydrogen generation,
in accordance with another embodiment of the present subject matter.
[0008] FIG. 2 (c) illustrates a control system of on-board hydrogen storage, in
accordance with an embodiment of the present subject matter.
[0009] FIG. 3 illustrates a method for on-board hydrogen generation, in
accordance with another embodiment of the present subject matter.
[00010] FIG. 4 illustrates a method for on-board hydrogen storage, in
accordance with an embodiment of the present subject matter.
DETAILED DESCRIPTION
[00011] Conventionally, systems utilizing hydrogen as an alternative fuel involve two modes, a first mode in which hydrogen is directly used as a fuel for the IC engine, and a second mode in which hydrogen is used as a fuel in fuel cells for later utilization as a power source for vehicles capable of being propelled by fuel cells. Hydrogen generally exists abundantly in nature in the form of hydrocarbons and water. To produce hydrogen on a commercial scale, various methods are employed. Generally, hydrogen is produced by reforming hydrocarbons or their derivatives, such as Methyl alcohol, in the presence of steam at high pressure and temperature, for example, at about the supercritical point of hydrocarbon and water mixture. Further, conventional systems for producing hydrogen require bulky reactors for carrying out the reformation reaction. These reactors use electric heating coils to attain high temperature and require a high capacity power source for operation.
[00012] Typically, on-board generation of hydrogen acted as ail important factor contributing towards overcoming the limitations associated with bulky hydrogen reactors. This type of hydrogen production also helps in lowering of emissions. Further, on-board generation of hydrogen also enable enhancing

combustion. Conventional systems of on-board hydrogen production involve hydrogen gas production from water by electrolysis, in which oxygen and water are supplied in appropriate proportions for production of hydrogen. [00013] Generally, the electrolysis method of producing on-board hydrogen involves electrolyzing water source stored in the vehicle based on several factors, for example, engine load requirement. The electrolysis of the water source results in separation of oxygen gas and hydrogen gas, which in turn is supplied to the IC engine as an alternative fuel. However, the process of on-board generation of hydrogen using electrolysis is a tedious process and involves several electric circuitry, which poses a serious threat for vehicle operation and also acts as a barrier for accommodation of required electric circuitry in the available space in the vehicle.
[00014] Further, the conventional techniques of using hydrogen as alternative fuel involve generating hydrogen elsewhere and storing for later utilization as a fuel in only those vehicles that are capable of being run on fuel cells. In such techniques, the challenge is often associated with powering the IC engines that are not adapted to be run on fuel cells. Further, prior storing of hydrogen and later utilization in case of vehicles capable of running both on IC engines and fuel cells also involve losses due to external generation of hydrogen. [00015] In an embodiment, the present subject matter provides a modified cylinder head that enable on-board production of hydrogen. The modified cylinder head assembly ensures that the IC engine optimally utilizes the exhaust gases for production of hydrogen. The modified cylinder head assembly helps to accommodate reactor for hydrogen production at an optimal location such that the required hydrogen is produced without heat losses. The integration of an additional chamber also called as a reaction chamber with the cylinder head enables optimal utilization of space in the IC engine. The integrated chamber accommodates.the reactor for hydrogen production without interfering with other components of the IC engine. Further, the integrated chamber of the cylinder head assembly is so disposed that it does not act as an obstruction for the rider. The integrated chamber of the cylinder head assembly secures the reactor for hydrogen production thereby preventing any leakage of hydrogen.

[00016] In an embodiment, the modified cylinder head that includes the integrated chamber enable hydrogen production under supercritical conditions without using a catalyst. In an embodiment, the present subject matter describes on-board production of hydrogen using methanol. The use of methanol as an on-board hydrogen source is attractive for IC engines in transportation applications because of its safe handling, low cost and ease of synthesis from a variety of naturally available sources such as coal, natural gas, and biomass. Further, methanol as a source of hydrogen provides high H/C ratio with low soot formation as compared to other hydrocarbons. Furthermore, methanol as a source of hydrogen is effective due to its low boiling point and ease of storage. Using methanol under sustained pressure and temperature helps in achieving hydrogen yields of approximately 70% to 75%.
[00017] Methanol reacts with water generally according to the following equation:
CHyOH + H20 -> 3H2 + C02
[00018] In an embodiment, the present subject matter relates to producing hydrogen by a process comprising the step of reacting methanol with water, at a pressure of at least about 220 bar and at a temperature of approximately 600°C. [00019] In another embodiment, the present subject matter relates to producing on-board hydrogen in an internal combustion engine provided with a separate methanol source, and a water source. Further, the exhaust gases from the internal. combustion engine acts as a heat source. In one embodiment, the internal combustion engine is further provided with a pressure pump helps in providing the methanol and the water in desired pressure to a reactor that produces oh-board hydrogen, which when heated by the exhaust gases expelled by the internal combustion engine generates hydrogen.
[00020] In an embodiment, the integrated chamber of the present subject for accommodating the reactor is integrated with the cylinder head of the IC engine. In one embodiment, the integrated chamber is integrated in such a manner that the entire chamber is mounted above the top portion of the cylinder block to enhance ease of manufacturing. Further, in one embodiment, the integrated chamber is integrated closer to the exhaust port to prevent heat losses.

[00021] In one embodiment, the integrated chamber is mounted in such a manner that the longitudinal axis of the integrated chamber is not in line to the longitudinal axis of the exhaust port. Further, the integrated chamber is provided with a flange for mounting of muffler. For example, in an embodiment, the integration of the integrated chamber with the cylinder head is applicable for different types of engines including single cylinder engine, multi cylinder engine, air-cooled engine, water-cooled engine, oil-cooled engine, and forced air-cooled engine.
[00022] In an embodiment, the reactor is mounted inside the integrated chamber of the cylinder head. The reactor is made of a material, for example, inconel 625 that is inert with hydrogen and other supercritical liquids. For example, such a material also ensures that the reactor sustains high temperature and pressure conditions. In another embodiment, the reactor is capable of being made with any other known material that exhibits similar properties as that of inconel 625, that is to say, being inert with hydrogen and other supercritical fluids. . In one embodiment, the reactor is mounted in such a manner that a fluid inlet, for example, for fluid such as methanol-water mixture is disposed proximal to the •exhaust port of the IC engine so that the heat from the exhaust gases is readily available for effective heating of the reactor. Similarly, a fluid outlet of the reactor is situated distally or away from the exhaust port.
[00023] In one embodiment, the reactor is coated with a noble metal, for example, platinum to enable quick heating of the methanol-water mixture. In another embodiment, the reactor is capable of being coated with any other noble metal that exhibits similar properties as that of platinum. Further, in one embodiment, the reactor is mounted in such a manner that there exists a substantial space between the outer surface of the reactor and the inner surface of the integrated chamber. The space provides effective passage for the exhaust gases to circulate around the reactor and allows the exhaust gases to impinge on the reactor wall. In one embodiment, the reactor is optionally provided with a heating element that enables quick heating of the methanol-water mixture to the required temperature within the shortest possible time.

[00024] Further, in an embodiment, the reactor is provided with a capacity of at least 45 cc for generating 1 standard litre per minute (SLPM) of Hydrogen. In one embodiment, the annular area of the space between the additional chamber and the reactor is approximately 2.5 times that of the exhaust port to prevent creation of back-pressure and engine performance variations. Further, in an embodiment, the reactor is mounted on the additional chamber of the cylinder head with the help of metal gasket joint arrangement for improved sealing and preventing leakage of hot gases. In another embodiment, other known sealing means that exhibits similar properties as that of the metal gasket joint arrangement is advantageously used.
[00025] In an embodiment, the present subject matter provides a control system for controlling the generation, storage, and supply of the alternate fuel, for instance, hydrogen in the vehicle. In one embodiment, a first container for storing a reforming medium, for example, water is provided. Similarly, a second container for storing a hydrocarbon source, for example, methanol is also provided. Both water and methanol are sent to the reactor through separate lines by means of individual pumps. As explained above, exhaust gas stream that is allowed to pass around the reactor enables generation of reformate gas, for example, hydrogen. An outlet stream of the hydrogen emerging out of the reactor is sent to a separator that separates any unreacted hydrocarbon from the reformate gas of hydrogen and recycles back to the reforming medium container through a recycle stream. The separated hydrogen is then sent to the intake side of the IC engine for use as an alternate fuel that ensures effective combustion.
[00026] In an embodiment, the control system of the present subject matter includes a plurality of sensors. The plurality of sensors help in monitoring flow of incoming water and methanol to the reactor, composition of incoming hydrocarbon, temperature around the reactor chamber, pressure of the outgoing reformate gas, and pressure of separated hydrogen gas exiting out of the separator. A controller receives the signals received from the plurality of sensors. In an embodiment, based on input signal received from the plurality of sensors, the controller determines the flow of incoming stream of water and methanol, which are independently regulated by separate flow regulating valves. Similarly, the

controller checks the pressure of the hydrogen exiting out of the reactor chamber through a pressure regulator. Further, in one embodiment, with the help of a back pressure regulator, the controller ensures that the pressure inside the reactor chamber is optimally maintained below a predetermined pressure level. The controller also enables controlling the flow of separated reformate gas to the intake side of the IC engine with the help of a flow controller.
[00027] In another embodiment, water from the first container that stores methanol is fed to the second container storing the reforming medium, for example, water instead of directly routing to the reactor. For instance, such an arrangement can be beneficial in commonly regulating the flow of the water-methanol mixture instead of regulating the two streams separately. Further, in one embodiment, the separated hydrogen exiting out of the separator is sent to a storage cylinder that stores hydrogen before supplying to the intake side of the IC engine for use as an alternate fuel.
[00028] In an embodiment, the present subject matter provides a method for controlling the generation, storage, and supply of on-board hydrogen that is capable of being used as an alternate fuel in a vehicle. For instance, the controller of the present subject matter receives inputs relating to composition, pressure, temperature, and flow rate from the plurality of sensors. For instance, the controller determines if the temperature input received from the temperature sensor is greater than or equal to a predetermined temperature of the reactor chamber. The controller also determines the composition of the incoming reaction mixture to the reactor chamber. Further, the controller determines if the pressure of the reactor chamber is more than a maximum predetermined pressure. Based on such a determination, the controller actuates the pressure regulator arid the back pressure regulator. Similarly, the controller also determines if the pressure of the hydrogen fuel exiting from the separator is greater than or equal a predetermined output pressure of hydrogen. Based on such a determination, the controller actuates opening/closing of the flow control valve to allow passage of the hydrogen to the storage container.

[00029] Further, in one embodiment, the present subject matter also provides a method for controlling the storage and supply of the hydrogen generated on-board the vehicle. For instance, as soon as the flow control valve is allowed to supply the hydrogen to the storage container, the controller determines whether the operating conditions of the IC engine is optimal for receiving the hydrogen reformate gas. After determining whether the operating conditions to be optimal, the controller identifies whether the pressure of the reformate gas is greater than a predetermined reformate gas pressure,, otherwise allows the reformate gas to be retained in the storage container. On determining the pressure of the reformate gas is suitable enough to be supplied to the engine, the controller actuates the outlet valve and allows the hydrogen reformate gas to pass through to the intake side of the IC engine. In an embodiment, the controller also adjust one or more engine parameters to enable the reformate gas received from the storage container to be used as an alternate fuel.
[00030] These and other advantages of the present subject matter would be described in greater detail in conjunction with the figures in the following description.
[00031] FIG; 1(a) illustrates an internal combustion (IC) engine, in accordance with an embodiment of the present subject matter. In an embodiment, the present subject matter describes an internal combustion (IC) engine 100. In one example, the IC engine 100 is. a two-stroke internal combustion engine. In another example, the IC engine 100 can be a four-stroke internal combustion engine. In one embodiment, the IC engine 100 includes a crankcase 110 connected to a charging device (not shown). The crankcase 110 houses a crankshaft (not shown). Further, a cylinder block 108 having a cylinder bore (not shown) is mounted on the crankcase 110. In one embodiment, the cylinder block 108 is provided with an induction valve (not shown) for enabling a unidirectional induction of a scavenging fluid, such as fresh air or a lean composition of charge formed by . mixture of air and fuel, into the crankcase 102. [00032] During operation of the IC engine 100, a piston (not shown) disposed . within the cylinder bore engages in reciprocating movement for effecting combustion of the air-fuel mixture that is drawn inside. In one example, the IC

engine 100 is provided with more than one cylinder bore. Further, the piston is connected to the crankshaft (not shown) through a connecting rod (not shown) to drive the crankshaft. Inside the cylinder bore, the piston has two extreme positions - a top dead centre (TDC) position when the IC engine 100 has completed a compression stroke and a bottom dead centre (BDC) position from where the piston commences actuation at the beginning of the compression stroke. [00033] Further, in an embodiment, the IC engine 100 of the present subject matter includes a cylinder head assembly 102. In one embodiment, the cylinder head assembly 102 includes a cylinder head 104, a cylinder head cover 112, and a reactor 106 disposed within an additional chamber, hereinafter referred to as an integrated chamber 114.
[00034] In one embodiment, the cylinder head 104 of the present subject matter includes one or more ports, for example, an intake port and an exhaust port (not shown). In one embodiment, the intake port is disposed on a first side of the cylinder head 104 while the exhaust port is disposed on a second side of the cylinder head 104. In one embodiment, the cylinder head 104 includes at least one inlet port for intake of charge into the cylinder block 108, and at least one exhaust port for discharge of combustion products from the cylinder bore of the cylinder block 108. In one embodiment, the intake port is connected to a combustion chamber (not shown) of the IC engine 100 for induction of charge into the combustion chamber. Each of the portsis provided with a valve to control the opening and closing of the ports. Further, the portsare provided with a valve seat, corresponding to each valve. The valve lifts and rests at the valve seat during the opening an closing of the ports.
[00035] In one embodiment, the cylinder head 104 is integrated with an integrated chamber 114. For example, in one embodiment, the integrated chamber 114 is moulded with the cylinder head 104 to form a continuous space. In one embodiment, the integrated chamber 114 has a cylindrical cross-section, while the cylinder head 104 has a different cross-section, for example, a rectangular cross-section. In one embodiment, the integrated chamber 114 is capable of receiving a reactor 106 inside a cavity 144.

[00036] In one embodiment, the integrated chamber 114 is disposed in such a manner that it adjoins the exhaust port. In one embodiment, the integrated chamber 114 is disposed with its longitudinal axis not in line with the longitudinal axis of the exhaust port. For example, the integrated chamber 114 can be inclined at any angle ranging from 1° to 179° and preferably in a range of 75° to 105° with respect to the longitudinal axis of the exhaust port.
[00037] In one embodiment, the integrated chamber 114 of the cylinder head 104 is disposed substantially above a plane intersecting the cylinder head 104 and the cylinder block 108. For example, moulding the integrated chamber 114 above an imaginary line passing in the intersection of the cylinder head 104 and the cylinder block 108 enhances the ease of manufacturing of the IC engine 100. [00038] FIG. 2 (a) illustrates a control system of on-board hydrogen generation, in accordance with an embodiment of the present subject matter. In an embodiment, the control system 1000 of the present subject matter includes a hydrocarbon container 1020, for example, a methanol container 1020, a reforming medium container 1040, for example, a water container 1040, a first pump 1120, a second pump 1140 coupled independently with flow regulating valves 202, 204 respectively. The control system 1000 of the present subject matter also includes a reforming reactor 106, a separator 1100, and a controller 200. The controller 200 receives inputs from one or more flow sensors F, G; hydrocarbon composition sensor C; temperature sensor T; pressure sensors P, Q and R through one or more input lines II, 12,13, 14, 15, 16 & 17 respectively. For instance, the controller 200 enables controlling the generation of hydrogen by means of one or more flow regulating valves 202, 204 at an inlet side. Further, in an embodiment, a pressure regulator 208 is provided along with a back pressure regulator 210 to maintain required pressures conditions. Further, in one embodiment, the control system 1000 of the present subject matter regulates outlet flow of the reformate gas by means of a flow controller 212. Further, pressure in storage and discharge is maintained by the control system 1000 using a check valve 216. Similarly, the controller 200 enables control of the input streams from the first and the second containers 1020, 1040 by means of output lines 01, and 02. Further, based on the pressure of the reactor chamber 106, the controller 200 controls the pressure

and/or back pressure of the reactor chamber 106 via output lines 03, and 04. Furthermore, the controller 200 also controls the output flow of the reformate gas i.e., hydrogen exiting from the separator 1100 via output line 05. [00039] In an embodiment, check valve 206 in inlet line and 214 in storage line are provided to avoid backflow of fluid due to pressure changes. Further, the hydrocarbon fuel for example, methanol, and the reforming medium, for example, water, stored in the first container 1020 and the second container 1040 respectively; are pumped via a first pump 1120, and a second pump 1140 to the reforming reactor 106. In one embodiment, the reaction mixture is mixed in duct/ inlet stream 1160 before entering the reforming reactor 106. The composition sensor C is mounted in the inlet stream 1160 for monitoring concentration of the inlet reaction mixture that sends signal to the controller 200 through the input line 13.
[00040] Further, flow sensor F & G monitors flow of water and methanol, respectively and sends signal to the controller 200 through input line II and 12. Based on a predetermined concentration and flowrate, the controller 200 adjusts flowrate of both water and methanol by opening or closing flow controlling valve 202 and 204 through output line 01 and 02. In an embodiment, the reaction mixture is pressurized to a predetermined pressure, for example, to a supercritical pressure of water i.e., 220 bar, in the reforming reactor 106 using the pumps 1120 and 1140. For example, in an. embodiment, the hydrocarbon inlet system described in the present subject matter includes two pumps 1120 and 1140, since the pressure required for achieving the reaction is high, for instance, 220 bar. Thus powering both the pumps 1120, 1140 for on-board hydrogen generation is not economical. In another embodiment, the pumps 1120, 1140 is capable of being driven by a crankshaft or a camshaft of the IC engine 100.
[00041] A check valve 206 is provided to avoid reverse flow of the reaction mixture when the exhaust gases flowing from the exhaust port of the IC engine heats the reaction mixture. For example, the reaction mixture is heated in the reforming reactor 106 till it reaches its supercritical condition, i.e., 220 bar and 600 deg C. The unused heat from the reactor 106 is expelled through an outlet stream 1220. The controller 200 monitors the temperature and pressure of the

reactor 106 using temperature sensor T and pressure sensor P respectively. For example, by receiving inputs through input line 14 and 15. Further, the controller 200 opens the outlet valve 208, through the output line 03. In an embodiment, the valve 208 is a: pressure release valve, which opens as soon as receiving the signal . from the controller 200 and allows to release the pressure. [00042] In an embodiment, in order to maintain the pressure inside the reactor 106, a back pressure regulator 210 is provided after the pressure regulator 208. For instance, the back pressure regulator 210 is a proportionate valve that maintains an upstream pressure. Hence, when the reactor pressure P is above the predetermined pressure limit, for example, 220 bar, the back pressure regulator 210 enables the pressure of the reactor 106 to be controlled and not to exceed beyond the 220 bar of pressure.
[00043] In one embodiment, during the reaction in the reactor 106, the controller 200 opens the back pressure regulator 210 through output line 04. For instance, opening the back pressure regulator 210 ensures that the pressure of the -reactor 106 do not exceed beyond the predetermined pressure limit. Further, the gases formed and expelled out of the reactor 106 are separated from unreacted reaction mixture in the separator 1100. In an embodiment, the separator 1100 is a phase separator that condense the unreacted reaction mixture and separate hydrogen from the unreacted reaction mixture. The controller 200 senses pressure in the separator 1100 using the pressure sensor Q that transmits the sensed pressure to the controller 200 through the input line 16. Based on the received pressure from the pressure sensor Q, the controller 200. regulates the pressure using the back pressure regulator 210. Once the desired conditions are reached, controller 200 opens the outlet for allowing the final reformate gas, for example, the final reformate gas includes hydrogen as its major component. The controller 200, in an embodiment, adjusts the flow rate of the final reformate gas using the mass flow controller 212 through the output line 05 in outlet stream 1180. The unreacted reaction mixture, in liquid state, is recycled back to the reforming medium container 1040 from the separator 1100 via a recycle stream 1260. [00044] FIG. 2 (b) illustrates a control system of on-board hydrogen generation, in accordance with another embodiment of the present subject matter.

In this embodiment, the inlet system includes a reforming medium, i.e., water container 1040 that acts as a mixer. The reaction mixture is supplied by a single pump, for example, the second pump 1140. Further, the hydrocarbon fuel, i.e., methanol container 1020 is connected to the reforming medium container 1040. In an* embodiment, a composition sensor C is installed in the reforming medium container 1040 for monitoring the concentration of hydrocarbon fuel in the reforming medium container 1040. In one embodiment, the recycle stream 1260 is connected to the reforming medium container 1040. For example, when the recycle stream 1260 carries a substantially larger quantity of the unreacted . reaction mixture than a predetermined level, the concentration of the hydrocarbon fuel in the reforming medium container 1040 decreases. The controller 200, on detectin the reduction in the concentration of the hydrocarbon fuel in the reforming medium controller 1040, opens the valve 202 through an output line 02 and allows the reforming medium, i.e., water to mix with the hydrocarbon fuel in the container 1040. The reaction mixture thus formed is then pressurized into the reforming reactor 106 by means of a single high pressure pump, for example, the second pump 1140. The inlet flowrate in the incoming stream 1160 is controlled by using a flowrate sensor F and the flow regulating valve 204 through the input line II and the output line 01 respectively.
[00045] FIG. 2 (c) illustrates a control system of on-board hydrogen storage, in accordance with an embodiment of the present subject matter. In an embodiment, the hydrogen generated on-board as explained above, is capable of being used as an. alternative fuel for powering the IC engine of the vehicle. In another embodiment, the alternative fuel thus generated can also be stored and used as a fuel for a vehicle operatin on a fuel cell. For instance, in case of a vehicle operated on the IC engine, the generated hydrogen can be routed directily to the intake side of the IC engine in one embodiment. However, in another embodiment, the hydrogen fuel thus generated can be initially stored in a storage container 1240 and subsequently depending upon one or more parameters determined by the controller 200, can be sent to the engine to be used as an alternate fuel. [00046] In one embodiment, the storage system for the hydrogen generated onboard incudes a check valve 214, the storage cylinder 1240, a pressure sensor

R, and an outlet valve 216. In an embodiment, the pressure of the hydrogen gas exiting the system 1000 is retained in a range of 5-6 bar, which is sufficient to store in the cylinder 1240. However, in another embodiment, a compressor 1300 is provided to further pressurize the hydrogen gas entering the storage system in order to effectively store the hydrogen in the cylinder 1240. The check valve 214 is mounted on an upstream line 1180 to arrest the backflow of hydrogen due to lower pressure in the outlet stream 1180. For achieving an uninterrupted supply of hydrogen gas based on the requirement of engine or the fuel cell, the controller 200 ensures that the hydrogen is stored in the container 1240 at a predetermined pressure limit. Further, the maximum pressure limit hydrogen can be stored in the container 1240 is also dependent on the maximum storing capacity of the container 1240. In an embodiment, the controller 200 receives signals from the pressure sensor R through the input line 17 and controls the pressure by actuating the outlet valve 216. For example, the outlet valve 216 opens when the generated hydrogen is supplied to the storage system. However, when hydrogen is not generated, the controller 200 closes the outlet valve 216 through the output line 06 so that a minimum required pressure is maintained inside the storage cylinder 1240. Further, even when the pressure of the storage cylinder 1240 reaches above a maximum threshold pressure limit, the controller 200 opens the outlet valve 216 through output, line 06 and allows the hydrogen to pass through to the intake side of the engine 100 through a second outlet stream 1280.
[00047] FIG. 3 illustrates a method for on-board hydrogen generation, in accordance with another embodiment of the present subject matter. For example, at step 304, the controller 200 of the present subject matter check whether all the valves in the control system 1000 are iii closed condition i.e. detects that there exists no flow. This enables the controller, at step 306, to receive input from the plurality of sensors through respective input lines. At steps 308 and 310, the controller initates the input system when the reforming reactor 106 is heated by the exhaust gas stream 1200 and when the temperature of the reactor 106 surpasses a minimum temperature set point, for example, 400°C. Thus avoiding an engine off condition when the exhaust gas stream 1200 stops heating the reforming reactor 106.

[00048] At step 312, once inlet is started, the controller 200 checks the composition of the inlet reaction mixture by means of the concentration sensor C through input line and accordingly, at step 314, adjusts the concentration of the inlet stream by adjusting flow through the valves 202 and 204 through the output lines 01 and 02. In another embodiment, the controller 200 is capable of adjusting the concentration of the inlet reaction mixture in the second container 1040 before pumping it to the reactor 106 by operating the valve 204 through the output line 02. Once the required temperature and pressure for the required supercritical condition are reached, at step 316 and 318, the controller 200 opens the valves 208 and 210 allowing resultant mixture to the separator unit 1100. However, if pressure and/or temperature falls below required supercritical condition, the controller 200 closes the outlet valve 208. In one embodiment, the pressure in the reactor 106 raises above the required pressure condition before the temperature condition is reached. In such cases, there is potential threat of very high pressure build up inside the reactor 106 as the same can damage the system and the associated components. In order to avoid such a situation, at step 320, the controller 200 checks if the pressure sensed by the pressure sensor P crosses a ; predetermined maximum pressure limit of 240 bar and accordingly, at step 318, opens the valve 208 to reduce the pressure.
[00049] Once the reactor output is generated, the controller 200, adjusts the back pressure regulating valve 210 in order to maintain the pressure P in the reactor 106. At step 322, when the pressure in the separator 1100 reaches the required pressure, for example, 5-7 bar, the controller 200 opens the flow controller 212 through output line 05 as indicated at step 324, so as to allow the hydrogen gas stream to the storage cylinder 1240. For example, in an embodiment, the valves 202, 204 & 208 are on-off type solenoid valve, while the valve 210 is proportionate valve.
[00050] FIG. 4 illustrates a method 400 for on-board hydrogen storage, in accordance with an embodiment of the present subject matter. At step 404, the controller 200 is initiated to begin the process of storage of on-board generated hydrogen as described in the methodology depicted in Fig. 3. At step 406, it is determined whether the reformate gas exits out of the flow control valve 212. In

case of reformate gas is coming out; at step 410, it is checked whether the engine operating condition is suitable, to receive the reformate gas. If it is determined that the operating conditions are favourable to receive hydrogen, the controller 200, at step 416, opens the outlet valve 216 to introduce hydrogen with other reformate gases into the intake side of the IC engine. However, if it is determined that the operating conditions are unfavourable to receive hydrogen, at step 412, by identifying whether the reformate pressure (R) is greater than a maximum predetermined pressure. At step 414, the hydrogen gas is stored in cylinder 1240 if it is determined that the pressure in the system is not above the maximum allowable pressure including cylinder pressure.
[00051] In an embodiment, if the storage cylinder is already filled with the reformate gas maintained at a requisite predetermined pressure level, at step 418, the hydrogen gas is delivered to the intake side of the engine as an alternate fuel by adjusting engine parameters to enable the engine to be operated using the hydrogen as alternate fuel. However, in case if there is no gas that is produced through the output valve 212, at step 408, it is determined whether the pressure of the gas availabe in the storage cylinder 1240 is greater than a minimum required pressure. In one embodiment, the outlet valve 216 is a on-off type solenoid valve *. or a proportionate valve based on the reformate gas demand from engine. [00052] The pre-set minimum temperature (T), composition (C), maximum pressure (P) of the system 1000, pressure (Q) to be maintained inside the separator 1100, upper and lower pressure limit in storage & supply unit (R) mentioned in controlling methods 300 and 400 are determined based on optimum conditions obtained by set of experiments. These values with process temperature & pressure conditions are stored in memory of the controller 200. Sample estimated values of these parameters are shown in table 1.

[00053] However, the control system 1000 for generation, storage, and supply of on-board hydrogen is capable of working at other values that are capable of yielding the intended results. In one example, the cylinders are formed of an alloy, for example, of metals including titanium, manganese, nickel, chromium or composite materials. In one example, the storage cylinder 1240 can also include metal hydride canisters for storing hydrogen/ reformate gas. In another example, a flash evaporator, condenser or modified radiator unit is capable of being used as a separator 1100. For example, in another embodiment, the system 1000 can also include a hydrogen purification unit installed before storing the reformate gas in the cylinder 1240 when there is a need for hydrogen of high purity. Another embodiment, depicts a membrane separator, a pressure swing adsorption unit (PSA) for achieving a purified hydrogen to be used as an alternate fuel. [00054] Although the subject matter has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. It is to be understood that the appended claims are not necessarily limited to the

features described herein. Rather, the features are disclosed as embodiments of the control system 1000 and the method 200 for operating the control system 1000.

1/we claim:
1. A control system (1000) for controlling the generation, storage, and supply of
on-board hydrogen in a motor vehicle, said control system comprising:
a first container (1040) for storing a predetermined quantity of reforming medium required for generation of hydrogen;
a second container (1020) for storing a predetermined quantity of hydrocarbon source required for generation of hydrogen; and
a reforming reactor (106) for receiving an inlet stream (1160) of mixture of hydrocarbon and reforming medium, said reforming reactor (106) is capable of generating hydrogen when an exhaust gas stream (1200) expelled from an exhaust port of an internal combustion engine (100) of said motor vehicle is allowed to pass through said reforming reactor (106), said reforming reactor (106) supplies generated hydrogen through an outlet stream (1220, 1180) to an intake port of said internal combustion engine (100).
2. The control system (1000) as claimed in claim 1, wherein the outlet stream (1220) of hydrogen from the reactor (106) is sent to a separator (1100), wherein said separator (1100) separates unreacted hydrocarbon from the outlet stream (1220) of hydrogen and recycle to the first container (1040), and wherein the separated hydrogen is sent to said intake port of the internal combustion engine (100).
3. The control system (1000) as claimed in claim 1, wherein the control systeifi (1000) includes plurality of sensors (F, G) for monitoring flow of inlet stream (1160) from said first container (1040) and said second container (1020) to the reforming reactor (106), and plurality of sensors (C, T, P) for monitoring composition of hydrocarbon in the inlet stream (1160), temperature of the reforming reactor (106), and pressure of the outlet stream (1220) of hydrogen respectively.
4. The control system (1000) as claimed in claim 2, wherein the control system (.1000) further includes a pressure sensor (Q) for monitoring the pressure of the separated hydrogen gas exiting out of the separator (1100).
5. The control system (1000) as claimed in any one of the preceding claims, wherein the control system (1000) includes a controller (200) for receiving signals from said plurality of sensors (F, G, C, T, P, Q), and wherein said controller (200) based at least on one or more of said signals received from said plurality of sensors (F, G, C, T, P, Q), regulates the flow of incoming reforming medium and the hydrocarbon by means of one or more flow regulating valves (204, 202), regulates the pressure of the hydrogen exiting out of the reforming reactor (106)

by means of at least one pressure regulator (208), optimally maintains the pressure in the reforming reactor (106) below a predetermined pressure level by means of at least one back pressure regulator (210), and controls the flow of separated hydrogen to the intake port of the internal combustion engine (100) by means of a flow controller (212).
6. The control system (1000) as claimed in claim 1, wherein the hydrocarbon stored in the second container (1020) is fed to the first container (1040) storing the reforming medium.
7. The control system (1000) as claimed in claim 2 or 5, wherein the outlet stream (1180) containing the separated hydrogen exiting out of the separator (1100) is fed to a storage cylinder (1240) for storing the hydrogen at a predetermined pressure level, before supplying to the intake port of the internal combustion engine (100) through a second outlet stream (1280), and wherein the controller (200) based at least on the signal received from a pressure sensor (R) controls the pressure of the hydrogen inside the storage cylinder (1240) by means of at least one check valve (216).
8. The control system (1000) as claimed in claim 7, wherein the outlet stream (1180) containing the separated hydrogen exiting out of the separator (1100) is fed to a compressor (1300) to optimize the pressure of the exiting hydrogen sufficient to store in the cylinder (1240), and wherein the outlet stream (1180) comprises a check valve (214) to arrest backflow of hydrogen due to low pressure of hydrogen exiting out of the separator (1100)
9. A method for controlling the generation, storage, and supply of on-board hydrogen in a motor vehicle, said method comprising:
receiving signals relating to composition, pressure, temperature, and flow rate from plurality of sensors (F, G, C, T, P), by a controller (200);
determining, based at least oil one or more received signals, by said controller (200):
temperature input received from said temperature sensor (T) is greater than or equal to a predetermined temperature of the reforming reactor (106),

composition of the reaction mixture received in the reforming reactor (106) through the inlet stream (1160),
pressure of the reforming reactor (106) is greater than a maximum predetermined pressure level, and
pressure of the hydrogen exiting from a separator (1100) is greater than or equal to a predetermined output pressure of hydrogen;
actuating at least one pressure regulator (208), at least one back pressure regulator (210), and at least one flow control valve (212, 214) to allow passage of hydrogen to a storage cylinder (1240).
10. The method for controlling the generation, storage, and supply of on-board hydrogen in a motor vehicle as claimed in claim 9, wherein the method further comprises:
determining the operating conditions of ah internal combustion engine (100) of said vehicle, by said controller (200);
identifying the pressure of the hydrogen is greater than a predetermined pressure level; and
actuating at least one check valve (216) and allowing the hydrogen from the storage cylinder (1240) to pass through to ah intake port of said internal combustion engine (100).