System and method for stabilizing the operation of a plant using hydrogen generated from a

Abstract

A system and method for stabilizing hydrogen flow to a downstream process in a facility determines a hydrogen density and pressure curve in a hydrogen storage unit for different target net hydrogen flow at different time intervals of a time range of a renewable energy availability curve, an operational target net hydrogen flow for the hydrogen feed to the downstream process is determined, a target direct hydrogen flow for the hydrogen feed to the downstream process and a target stored hydrogen flow for the hydrogen feed are determined, and operation of the downstream process is controlled based on the operational target hydrogen flow.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 647,500, filed May 14, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] The currently disclosed information pertains to industrial processes that use hydrogen produced from low-carbon energy sources. Background Technology

[0004] Traditionally, the hydrogen required for downstream processes such as ammonia and methanol production is produced by processing hydrocarbon feedstocks through methods such as natural gas reforming, partial oxidation of hydrocarbons, or methane pyrolysis—all of which generate carbon dioxide emissions. Alternative hydrogen sources are being adopted, such as electrolyzers / electrolysis processes, which require only water and electricity. If renewable energy powers the electrolyzer, hydrogen can be produced without carbon emissions. However, because hydrogen production processes require steady-state conditions, such as a constant hydrogen feed flow rate, there may be issues with using renewable energy sources when operating electrochemical systems such as electrolyzers.

[0005] Renewable energy sources, such as wind or solar power, are susceptible to changes in environmental conditions, such as reduced wind speeds or severe weather. Decreased wind speeds or reduced solar radiation can lead to less available electricity. This reduced electricity, in turn, causes hydrogen production sources (such as electrolyzers) to produce less hydrogen feedstock, which affects the production of the final product.

[0006] Since the operating load of downstream production processes needs to be as stable as possible, it is necessary to minimize the regulation of the hydrogen flow rate to downstream production processes. At the same time, based on the available renewable energy curve, other available hydrogen sources, and available hydrogen inventory, it is necessary to account for the current and future value of renewable energy, which is required to operate within the allowable operating pressure range. Summary of the Invention

[0007] The examples of systems and methods for the stable operation of facilities using hydrogen can substantially avoid one or more problems caused by the limitations and disadvantages of related technologies, or at least provide the public with a useful alternative where hydrogen is produced from low-carbon energy.

[0008] In the embodiments, a system and method for stabilizing the flow of hydrogen to downstream processes in a facility that includes a hydrogen storage unit and is powered by low-carbon energy are described.

[0009] In the embodiments, the described systems and methods enable efficient production while using dynamic energy sources such as renewable energy to power processes whose stability is affected by the dynamic energy supply.

[0010] In one embodiment, for different target net hydrogen flow rates at different time intervals within a time range of the renewable energy availability curve, the hydrogen density and pressure curves in the hydrogen storage unit are determined. This may include determining the mass of hydrogen produced at each time interval throughout the entire time range; determining the relationship between the pressure and density of hydrogen in the hydrogen storage unit; determining the hydrogen density in the hydrogen storage unit at each target net hydrogen flow rate for each time interval within the time range; and determining the pressure curve of the hydrogen storage unit for each time interval within the time range.

[0011] In an embodiment, the system and method may include determining different target net hydrogen flow rates for different time intervals within a time range of a renewable energy availability curve; determining hydrogen density and pressure curves in a hydrogen storage unit; determining a first target net hydrogen flow rate for hydrogen feed to downstream processes for a given time interval within the time range, wherein the first target net hydrogen flow rate corresponds to the maximum time required for hydrogen pressure in the hydrogen storage unit to exceed a high-pressure limit or a low-pressure limit; determining a second target net hydrogen flow rate for hydrogen feed to downstream processes for a given time interval within the time range, wherein the second target net hydrogen flow rate corresponds to the pressure curve of the hydrogen storage unit with the smallest deviation from the high-pressure or low-pressure safety limit of the hydrogen storage unit; setting the larger of the first target net hydrogen flow rate and the second target net hydrogen flow rate as the operating target net hydrogen flow rate; and controlling the operation of the downstream process based on the operating target net hydrogen flow rate.

[0012] In one embodiment, controlling the operation of downstream processes based on the target net hydrogen flow rate may include sending the target net hydrogen flow rate to an advanced regulation and control system, a user interface, or both.

[0013] In the embodiments, the downstream processes may include ammonia synthesis, methanol synthesis, or any other process involving the use of renewable energy and / or one or more hydrogen sources.

[0014] In an embodiment, the system and method may include a non-transitory computer-readable medium storing computer-readable instructions that, when executed by a processor, cause the processor to: determine hydrogen density and pressure curves in a hydrogen storage unit for different target net hydrogen flow rates at different time intervals within a time range of a renewable energy availability curve; determine a first target net hydrogen flow rate for hydrogen feed to a downstream process for a given time interval within the time range, wherein the first target net hydrogen flow rate corresponds to the maximum time required for the hydrogen pressure in the hydrogen storage unit to exceed a high-pressure limit or a low-pressure limit; determine a second target net hydrogen flow rate for hydrogen feed to a downstream process for a given time interval within the time range, wherein the second target net hydrogen flow rate corresponds to the pressure curve of the hydrogen storage unit that deviates least from a safety limit; set the larger of the first target net hydrogen flow rate and the second target net hydrogen flow rate as the operating target net hydrogen flow rate; and apply the operating target net hydrogen flow rate to control the operation of the downstream process.

[0015] In an embodiment, the process of determining the hydrogen density and pressure curves in a hydrogen storage unit for different target net hydrogen flows at different time intervals within a time range of a renewable energy availability curve may include: a processor determining the mass of hydrogen produced at each time interval throughout the entire time range; determining the relationship between the pressure and density of hydrogen in the hydrogen storage unit; determining the hydrogen density in the hydrogen storage unit at each target net hydrogen flow rate for each time interval within the time range; and determining the pressure curve of the hydrogen storage unit for each time interval within the time range.

[0016] In one embodiment, the control of the operation of the downstream process may be based on an operating target net hydrogen flow rate, which includes sending the operating target net hydrogen flow rate to an advanced regulation and control system, a user interface, or both.

[0017] In an embodiment, a system and method for regulating the flow rate of hydrogen to a process leading to a product in a facility is described, the hydrogen being generated using a low-carbon energy source, the facility having downstream production process units. In an embodiment, the downstream production process unit may include a unit for ammonia synthesis, methanol synthesis, or any other unit involving the use of renewable energy and / or one or more hydrogen sources. In an embodiment, the system and method may include supplying energy to the facility, wherein at least a portion of the supplied energy comes from a low-carbon energy source dependent on at least one environmental parameter; assessing the energy availability of the low-carbon energy source over a selected time period using the at least one environmental parameter; forming a hydrogen feed to the downstream production process unit using at least one of the following: (i) a primary hydrogen feed generated from a hydrogen source powered by the low-carbon energy source, and (ii) a supplementary hydrogen feed; controlling the formation of the hydrogen feed using an advanced regulation controller (ARC), the ARC being configured to generate a setpoint for the hydrogen feed using the assessed energy availability; and producing the product by supplying the formed hydrogen feed to the downstream production process unit, wherein the hydrogen feed arriving at the downstream production process unit is stabilized by the methods described herein.

[0018] In one embodiment, a facility using low-carbon energy is described, which may include: a downstream production process unit; a low-carbon energy source dependent on at least one environmental parameter; a hydrogen source powered by the low-carbon energy source; a hydrogen storage unit arranged to receive hydrogen from the hydrogen source; a hydrogen feed to the downstream production process unit and fluidly connected to the hydrogen storage unit; a system described herein for stabilizing the flow rate of hydrogen reaching the downstream process; and a product output. In another embodiment, the downstream production process unit is an ammonia synthesis unit, a methanol synthesis unit, or any other unit involving the use of renewable energy and / or one or more hydrogen sources.

[0019] It should be understood that certain features of this disclosure have been generalized quite broadly to facilitate a better understanding of the following detailed description and to recognize its contribution to the art. Of course, there are other features of this disclosure that will be described below, and in some cases they will constitute the subject matter of the appended claims. Attached Figure Description

[0020] To gain a detailed understanding of the current disclosure, reference should be made to the following detailed description in conjunction with the accompanying drawings, in which the same elements are given the same reference numerals, wherein:

[0021] Figure 1 The schematic diagram illustrates a low-carbon process for synthesizing the final product via a downstream process according to an embodiment of the current disclosure, wherein the downstream process uses hydrogen produced from low-carbon energy.

[0022] Figure 2 The hydrogen pressure curve in hydrogen storage unit 112 is shown, with iterative values ​​of the target hydrogen flow rate for the energy availability curve over a sample 24-hour range.

[0023] Figure 3 The safety margins for the high and low operating pressure limits applied to hydrogen storage unit 112 are shown.

[0024] Figure 4 A description of an example of a method executed by system 150 is shown. Detailed Implementation Plan

[0025] In some respects, the current disclosures provide systems and related methods for stabilizing and optimizing the hydrogen load reaching downstream production units, even when hydrogen is produced with high variability from low-carbon energy sources (such as electrolyzers) due to changes in the available renewable energy curve.

[0026] Specific embodiments of the present disclosure are shown in the accompanying drawings, which will be described in detail herein. It should be understood that the present disclosure should be regarded as an illustration of the principles of the present disclosure and is not intended to limit the present disclosure to the content illustrated and described herein.

[0027] In embodiments, the systems and methods described herein may be implemented in facilities including downstream processes or downstream production process units. The nature of the downstream processes or downstream production process units is not limited. In embodiments, downstream processes may include ammonia synthesis, methanol synthesis, or other processes involving the use of renewable energy and / or one or more hydrogen sources. In embodiments, downstream production process units may include equipment for producing or synthesizing materials. In embodiments, downstream production process units include one or more reactors. In embodiments, downstream production process units may also include equipment other than one or more reactors, such as one or more heat exchangers or heaters, one or more separators, one or more flow pumps, or any combination thereof, required for producing or synthesizing the desired material. In embodiments, downstream production process units include equipment configured for ammonia production or synthesis (e.g., an ammonia synthesis unit), equipment including reactors configured for methanol production or synthesis (e.g., a methanol synthesis unit), or other production equipment involving the use of renewable energy and / or one or more hydrogen sources.

[0028] See Figure 1The diagram schematically illustrates a non-limiting embodiment of facility 100 in which the systems and methods described herein may be implemented. In an embodiment, facility 100 may include a downstream production process unit 120 using hydrogen. In an embodiment, downstream production process unit 120 may also employ one or more feed streams 121. In an embodiment, downstream production process unit 120 may produce one or more product streams 122. In an embodiment, product stream 122 may contain ammonia or methanol. In an embodiment, product stream 122 may contain other materials.

[0029] In this embodiment, to reduce or eliminate carbon emissions, low-carbon energy 10 may be used to supply electrical power to one or more components of facility 100. In this embodiment, the power supply of low-carbon energy 10 may vary and / or be inconsistent, thus affecting the power output of low-carbon energy 10. Because the power output of low-carbon energy 10 may fluctuate due to external influences such as weather conditions, the power supply from low-carbon energy 10 may experience prolonged interruptions or capacity reductions. In this embodiment, even if low-carbon energy 10 does not always provide a stable and continuous power supply, it can still be used to power facility 100 in the implementation of the systems and methods described herein. Therefore, it is emphasized that terms such as “power supply” or “power supply” do not require an uninterrupted supply of electricity or any specific minimum requirement for power.

[0030] In one embodiment, downstream production process unit 120 receives one or more feed streams 121. In another embodiment, the one or more feed streams 121 provide downstream production process unit 120 with one or more materials to react with hydrogen to generate product stream 122. In another embodiment, downstream production process unit 120 receives hydrogen feed 116. In another embodiment, hydrogen feed 116 can be supplied via a hydrogen supply line 115 fluidly connected to hydrogen feed 116. In another embodiment, hydrogen supply line 115 can be directly supplied by hydrogen source 111. Downstream production process unit 120 can be powered by low-carbon energy 10 via power supply line 12 and / or by a second energy source 20 (e.g., the power grid) via power supply line 23. Second energy source 20 can also supply power to hydrogen source 111 via power supply line 21 and to hydrogen storage unit 112, such as a storage tank, via power supply line 22. Second energy source 20 can operate independently of facility 100. In other words, second energy source 20 is neither controlled by nor dependent on facility 100.

[0031] In one embodiment, facility 100 may include a hydrogen production unit 110. In another embodiment, the hydrogen production unit 110 may use a low-carbon process to generate hydrogen from a hydrogen source 111, with a direct hydrogen supply line 115 originating from the hydrogen source 111. In another embodiment, electricity for the hydrogen production process may be supplied by a low-carbon energy source 10 via a power supply line 11. In one arrangement, the hydrogen production unit 110 may include a hydrogen source 111 and a hydrogen storage unit 112. In another embodiment, the hydrogen source 111 may be an electrolyzer. The hydrogen source 111 may generate hydrogen for the direct hydrogen supply line 115 and / or for hydrogen storage feed 113 reaching the hydrogen storage unit 112, the direct hydrogen supply line 115 being fluidly connected to a hydrogen feed 116 reaching the downstream production process unit 120. For clarity only, the direct hydrogen supply line 115 and the hydrogen storage feed 113 are shown separately. A common outflow line (not shown) from hydrogen source 111 can be used to selectively direct the hydrogen flow to either or both of the downstream production process unit 120 and the hydrogen storage unit 112. It should be noted that the current teachings are not limited to a hydrogen production unit 110 that uses only an electrolyzer as the hydrogen source 111 to produce hydrogen for the direct hydrogen supply line 115 and / or the hydrogen storage feed 113. The current teachings are equally applicable to any system or method that produces hydrogen via a low-carbon process using electricity.

[0032] In one embodiment, the hydrogen storage unit 112 may provide supplemental hydrogen feed to the downstream production process unit 120. In one arrangement, the hydrogen storage unit 112 stores hydrogen and supplies the stored hydrogen to the downstream production process unit 120 as needed via a hydrogen supply line 114 fluidly connected to the hydrogen feed 116. In one embodiment, one or more valves (not shown) may be used to control the flow rate of hydrogen from the hydrogen source 111 through the hydrogen storage feed 113 to the hydrogen storage unit 112. Similarly, in one embodiment, one or more valves (not shown) may be used to control the flow rate of hydrogen from the hydrogen storage unit 112 through the hydrogen storage supply line 114 to the hydrogen feed 116, which in turn reaches the downstream production process unit 120.

[0033] The amount of hydrogen in the hydrogen storage unit 112 can vary depending on the amount of hydrogen produced by the hydrogen production unit 110 and guided to the hydrogen storage unit 112 via the hydrogen storage feed 113, as well as the amount of hydrogen guided to the downstream production process unit 120 via the hydrogen storage supply line 114.

[0034] In some implementations, depending on the available sources for facility 100, hydrogen storage unit 112 may be supplied by a second hydrogen source 30 via a second hydrogen feed 32. Furthermore, excess hydrogen in hydrogen storage unit 112 may be discharged to the second hydrogen source 30. The second hydrogen source 30 may also provide supplemental hydrogen feed to downstream production process unit 120. For example, hydrogen may be supplied directly from the second hydrogen source 30 to downstream production process unit 120 via a direct second hydrogen feed 31. In embodiments, the second hydrogen source 30 may be a hydrogen source operating independently of facility 100. That is, the second hydrogen source 30 may be connected to a power and / or hydrogen source independent of facility 100.

[0035] In this embodiment, to stabilize the operating load of the downstream production process unit 120, the regulation of the direct hydrogen flow rate in the hydrogen supply line 115 and the hydrogen supply line 114 from the hydrogen storage unit 112 can be minimized, while the predicted renewable energy curve and the hydrogen inventory in the hydrogen storage unit 112 are taken into account. These hydrogen inventories may be required to operate the downstream production process unit 120, even when the availability of renewable energy changes dynamically due to weather changes and day-night cycles.

[0036] In one embodiment, facility 100 includes system 150 as described herein. In another embodiment, system 150 uses multi-step iterative calculations to achieve a stable and maximum hydrogen load reaching downstream production process unit 120 while managing changes in the renewable energy curve and the resulting variations in hydrogen production at hydrogen production unit 110. In another embodiment, system 150 may include logic, computation, algorithms, patterns, microprocessors, storage modules, bidirectional signal transmission devices, display devices, input devices, and other components suitable for receiving, processing, storing, and transmitting information.

[0037] In an embodiment, system 150 may include any number of logical, program, and physical components. In an embodiment, system 150 may include one or more processors and memories that are communicatively coupled to each other. In an embodiment, one or more input / output devices such as a display, keyboard, speaker, microphone, computer mouse, etc., may be coupled to one or more controllers. In an embodiment, system 150 may include one or more communication elements such as a receiver, transmitter, transceiver, or similar structure to enable wired and / or wireless communication.

[0038] In this embodiment, the memory associated with system 150 may be a non-transitory computer-readable medium. Storage can be implemented using any suitable storage technology, such as static random access memory (SRAM), synchronous dynamic random access memory (SDRAM), non-volatile / flash memory, or any other type of memory capable of storing information.

[0039] In embodiments, the memory may be used to store logical instructions, including but not limited to one or more software modules and / or other sufficient information for running, security procedures, and / or routine maintenance processes. In embodiments, the logical instructions may be used to run, control, and / or monitor the operation of the system and / or one or more of its subcomponents. In embodiments, the memory may store the running system and one or more software applications, instructions, programs, and / or data to implement the methods described herein and the functions belonging to the respective systems. Any operation of the system may be implemented in hardware, software, or a combination thereof. In a software context, operation means that, when executed by one or more processors, computer-executable instructions stored on one or more computer-readable storage media perform the operation. Computer-executable instructions may include programs, objects, routines, data structures, components, etc., that perform one or more functions or implement a particular abstract data type.

[0040] In an embodiment, system 150 receives or includes (e.g., stored in memory) information 140 related to the operation of facility 100. In an embodiment, information 140, or any sub-part thereof, can be used to execute decisions made by system 150. In an embodiment, information 140 may include facility-specific information 141 and / or non-facility-specific information 142. Facility-specific information 141 may include operating parameters such as the current setpoints of hydrogen source 111, hydrogen storage unit 112, downstream production process unit 120, other feeds required by the downstream production unit, and / or multiple other components related to facility 100. Facility-specific information 141 may also include operating parameters such as pressure, temperature, flow rate, energy consumption, etc. Non-facility-specific information 142 may include environmental parameters such as current weather conditions and weather forecasts, which may include information related to temperature, wind speed, wind direction, gusts, air pressure, precipitation, cloud cover, humidity, dew point, diurnal cycle, etc. This information may be current, historical, and / or forecast. Non-facility-specific information may include non-weather-related information, such as the current and anticipated energy usage of other energy consumers in the adjacent area, the availability of the second energy source 20, the availability of the second hydrogen source 30, etc. It should be noted that the above-mentioned facility-specific and non-facility-specific information is illustrative only. Facility 100, the geographical location of Facility 100, and the design and configuration of infrastructure near Facility 100 may require facility-specific and / or non-facility-specific information not explicitly listed above.

[0041] In one embodiment, system 150 performs iterative calculations to determine the current and future values ​​of the internal pressure of hydrogen storage unit 112 over the entire time span of a given renewable energy availability curve. In another embodiment, system 150 uses the current and future values ​​of the pressure in hydrogen storage unit 112 over the entire time span of the renewable energy availability curve to determine a target net hydrogen flow rate to downstream production process unit 120 for a given renewable energy availability curve, and subsequently determines a target direct hydrogen flow rate in hydrogen supply line 115 and a target stored hydrogen flow rate in hydrogen supply line 114.

[0042] In this embodiment, system 150 is configured to perform rolling and dynamic calculations of the amount of hydrogen produced by hydrogen source 111 at a specific frequency throughout the duration of the renewable energy availability curve. In this embodiment, any frequency not longer than the time step for updating the energy availability curve can be used. This frequency should be long enough to keep the operation of downstream processes and / or downstream production process units as stable as possible. For the purposes of this description, this frequency can be considered equal to the frequency of renewable energy curve updates. This is merely an example.

[0043] The frequency at which the target net direct hydrogen flow rate of hydrogen feed 116 is reset, and subsequently the target direct hydrogen flow rate in hydrogen supply line 115 and the target stored hydrogen flow rate in hydrogen supply line 114, can depend on the volume of hydrogen storage unit 112, the rated capacity of downstream production process unit 120, and / or the time required for the pressure of hydrogen storage unit 112 to reach its high or low constraint limits. In an embodiment, system 150 may be configured to perform calculations to determine the magnitude and frequency of changes in the maximum target net direct hydrogen flow rate of hydrogen feed 116 to downstream production process unit 120, and subsequently the magnitude and frequency of changes in the maximum target direct hydrogen flow rate in hydrogen supply line 115 and the maximum target stored hydrogen flow rate in hydrogen supply line 114, these calculations may be based on thermodynamics and first principles.

[0044] In an embodiment, system 150 is configured to predict the quality and pressure of hydrogen in hydrogen storage unit 112 over a given renewable energy availability curve over a time span, and can use this information to establish the maximum target net hydrogen flow rate of hydrogen feed 116 to downstream production process unit 120, and subsequently determine the target direct hydrogen flow rate in hydrogen supply line 115 and the target stored hydrogen flow rate in hydrogen supply line 114.

[0045] Figure 4 The diagram illustrates an example of a process that can be executed by system 150, as described in more detail below.

[0046] In this embodiment, system 150 is configured to iteratively calculate the target net hydrogen flow rate to the hydrogen feed 116 arriving at the downstream production process unit 120 using different assumptions, covering a range from the adjusted capacity of the downstream production process unit 120 to its full rated capacity. In each iteration, the target net direct hydrogen flow rate to the hydrogen feed 116 can be progressively increased or decreased by a predetermined amount, which depends on the capacity of the downstream production process unit 120.

[0047] In this embodiment, system 150 receives one or more of the following inputs 401 for use in each iteration when calculating the target net direct hydrogen flow rate to the hydrogen feed 116 reaching the downstream production process unit 120:

[0048] o A renewable energy availability curve over a certain period of time, which can be provided by low-carbon energy operators.

[0049] The pressure of hydrogen storage unit 112 at the beginning of the same time range.

[0050] The efficiency of hydrogen source 111 is defined as the rate of hydrogen production from hydrogen source 111 as a function of available energy.

[0051] The capacity of hydrogen storage unit 112,

[0052] The permissible operating pressure range of hydrogen storage unit 112,

[0053] o is the assumed value of the target net hydrogen flow rate to reach the hydrogen feed 116 of the downstream production process unit 120.

[0054] like Figure 4 As illustrated, at 402, system 150 can then determine the target value of the net hydrogen flow rate of hydrogen feed 116.

[0055] Step 1 – In this embodiment, system 150 determines the mass of hydrogen produced at each time interval over the duration of the entire renewable energy generation curve's available timeframe, based on the efficiency of hydrogen source 111 and an assumed target net hydrogen flow rate to hydrogen feed 116 reaching downstream production process unit 120. In this way, system 150 can establish a curve of hydrogen flow rate from hydrogen source 111 to hydrogen storage unit 112 as a function of time for the entire duration of the renewable energy curve's available timeframe.

[0056] Step 2 – In this embodiment, system 150 determines the relationship between hydrogen pressure and density in hydrogen storage unit 112 based on gas law data at 40 degrees Celsius and the operating pressure range between the lower and upper limits of hydrogen storage unit 112.

[0057] Step 3 – In this embodiment, system 150 determines the hydrogen density in hydrogen storage unit 112 at the start of the given renewable energy availability curve's time range based on the pressure in hydrogen storage unit 112 at the start of the given renewable energy availability curve's time range. For iterative calculations of the target net direct hydrogen flow rate arriving at downstream production process unit 120 each time, system 150 can determine the hydrogen density in hydrogen storage unit 112 at each time interval spanning the entire time range of the given renewable energy availability curve. In this embodiment, the hydrogen density in hydrogen storage unit 112 is determined based on the net change in hydrogen mass in hydrogen storage unit 112 and the volume of hydrogen storage unit 112. In this way, system 150 can establish a hydrogen density curve in hydrogen storage unit 112 for the entire time range of the given renewable energy availability curve at the start of the given renewable energy availability curve's time range.

[0058] Step 4 – In an embodiment, based on the hydrogen density curve in the hydrogen storage unit 112 determined in Step 3, the system 150 can determine the pressure curve of the hydrogen storage unit 112 for each time interval over the entire duration of a given renewable energy availability curve. In an embodiment, the pressure curve of the hydrogen storage unit 112 can be determined based on the gas law data obtained by regression from the first principle, as described in Step 2 above.

[0059] In the embodiment, via steps 3 and 4 above, for each assumed value of the target net hydrogen flow rate to the hydrogen feed 116 reaching the downstream production process unit 120 at each iteration, the system 150 establishes hydrogen density and pressure curves in the hydrogen storage unit 112 for each time interval of the entire duration of the time range of the given renewable energy availability curve.

[0060] In an embodiment, system 150 can repeat steps 1 to 4 above for each consecutive assumed value of the target net hydrogen flow rate to the hydrogen feed 116 reaching the downstream production process unit 120. In this way, system 150 can establish a hydrogen density and pressure profile in hydrogen storage unit 112 for the entire duration of a given renewable energy availability curve over a given time range.

[0061] In an embodiment, based on the density and pressure curves in the hydrogen storage unit 112 for the entire duration of the time range of a given renewable energy availability curve, the system 150 can determine a target net hydrogen flow rate for the hydrogen feed 116 of the downstream production process unit 120 for a given time interval.

[0062] In this embodiment, the system 150 may consider a safety margin for the hydrogen storage unit 112 when making this determination. In this embodiment, the safety margin for the hydrogen storage unit 112 may be user-defined and / or previously uploaded to the system 150. In this embodiment, the system 150 may apply safety margins to both the high and low operating pressure limits of the hydrogen storage unit 112.

[0063] In an embodiment, in order to determine the target net hydrogen flow rate of the hydrogen feed 116 to the downstream production process unit 120 for a given time interval, the system 150 considers at least one of the following two criteria to select the optimal target hydrogen flow rate to reach the downstream production unit.

[0064] Standard 1 – For each iteration of the target hydrogen flow rate calculation, System 150 analyzes the pressure curve over the time range of the renewable energy curve and plots the pressure curve over the entire time range, such as... Figure 2 As shown. In one embodiment, system 150 compares each calculated pressure value with the design high-pressure limit or low-pressure limit of hydrogen storage unit 112. In one embodiment, system 150 determines the time required for the hydrogen pressure in hydrogen storage unit 112 to exceed the high-pressure limit or low-pressure limit. In one embodiment, these determined time values ​​may be stored in an array. In one embodiment, system 150 then selects the target net hydrogen flow rate to the hydrogen feed 116 reaching downstream production process unit 120 as the maximum value of all elements in the array.

[0065] Standard 2 – For each iterative calculation using the assumed target hydrogen flow rate, system 150 determines the total deviation (area under the curve, e.g., of the pressure curve of hydrogen storage unit 112 within the time range of the renewable energy curve from the allowable pressure limit) of the hydrogen storage unit 112. Figure 3 (As shown in the shaded area), the permissible pressure limit is calculated from the design high and low safety pressure limits of the hydrogen storage unit 112 based on a user-defined safety margin (positive or negative). In an embodiment, the system 150 stores the calculated value of the total deviation (area under the curve) of each pressure curve from the high or low safety limit in an array. The result of each of these calculations represents a time example when the pressure curve of the hydrogen storage unit 112 intersects with the high or low safety pressure limit of the hydrogen storage unit 112. In an embodiment, the system 150 determines the curve with the smallest deviation from the safety limit (i.e., the smallest area under the curve) as the optimal iterative target net hydrogen flow rate for the hydrogen feed 116.

[0066] In this embodiment, system 150 selects the larger of two target hydrogen flow rates calculated by criteria 1 and 2 as the operating target net hydrogen flow rate to reach downstream production process unit 120.

[0067] In one embodiment, system 150 determines a target flow rate value for the hydrogen storage flow in hydrogen supply line 114 based on maintaining the hydrogen pressure in hydrogen storage unit 112 within the pressure range that enables the most economical operation of hydrogen storage unit 112. This range value can be based on design parameters as input to system 150. In another embodiment, based on the determined target hydrogen storage flow rate in hydrogen supply line 114 and the target net hydrogen flow rate to hydrogen feed 116 reaching downstream production process unit 120, system 150 determines the target flow rate value for direct hydrogen supply line 115 as the difference between the target net hydrogen flow rate of hydrogen feed 116 and the hydrogen storage flow rate in hydrogen supply line 114.

[0068] In one embodiment, system 150 is configured to automatically recalculate the target net hydrogen flow rate to the hydrogen feed 116 reaching the downstream production process unit 120 to illustrate an updated renewable energy generation curve.

[0069] In this embodiment, if the device requires operation, the device operator using the user interface 170 can overturn the automatic recalculation of the target net hydrogen feed 116 and can manually trigger the system 150 at any time to recalculate the target direct hydrogen flow rate in the hydrogen supply line 115 leading to the downstream production process unit 120 and the target hydrogen storage flow rate in the hydrogen supply line 114.

[0070] In this embodiment, at 403, system 150 produces one or more of the following outputs:

[0071] 1. The target net hydrogen flow rate for hydrogen feed 116;

[0072] 2. The target direct hydrogen flow rate in the hydrogen supply line 115 leading to the downstream production process unit 120 and the target hydrogen storage flow rate in the hydrogen supply line 114;

[0073] 3. Recalculate the time interval between the new target direct hydrogen flow rate in hydrogen supply line 115 leading to downstream production process unit 120 and the target hydrogen storage flow rate in hydrogen supply line 114.

[0074] In one embodiment, the output of system 150 is used to generate a setpoint for the operation of facility 100.

[0075] In an embodiment, facility 100 may include an advanced regulation and control system (hereinafter referred to as ARC) 130. In an embodiment, ARC 130 may include logic, computing, algorithms, patterns, microprocessors, memory modules, bidirectional signal transmission devices, display devices, input devices, and other components suitable for receiving, processing, storing, and transmitting information.

[0076] In an embodiment, ARC130 may be configured to determine one or more setpoints 131 for controlling one or more operations of facility 100. ARC130 may determine the setpoint(s) based on a predicted renewable energy curve of low-carbon energy 10 and / or the energy availability of secondary energy 20. ARC130 may also determine the setpoint(s) 131 based on a target net hydrogen flow rate to the hydrogen feed 116 reaching the downstream production process unit 120. As used herein, “setpoint” is a value associated with the desired output, response, behavior, or operating state of a process component. A setpoint may be a numerical value, a numerical range, an upper limit, or a lower limit. “Control” means adjusting, stopping, starting, modifying, increasing, decreasing, and / or maintaining one or more states, conditions, and / or parameters associated with a given operation. As further described below, the setpoint(s) 131 are transmitted to a distributed control system (hereinafter referred to as “DCS”) 160 of facility 100.

[0077] In an embodiment, ARC130 may use information 140 to determine one or more setpoints 131.

[0078] In an embodiment, ARC130 can determine and / or control increasing or decreasing the hydrogen flow rate from the primary hydrogen source 111 to the hydrogen storage unit 112, increasing or decreasing the hydrogen flow rate from the primary hydrogen source 111 to the downstream production process unit 120, and / or increasing or decreasing the hydrogen flow rate from the hydrogen storage unit 112 to the downstream production process unit 120.

[0079] In an embodiment, ARC130 may establish one or more setpoints 131 for facility 100 to help maintain the stability of downstream processes and / or downstream production process units, even when the predicted energy curve of low-carbon energy 10 exhibits high variability over a period of time. When establishing one or more setpoints 131, ARC130 may consider one or more facility-specific pieces of information 141, such as minimum power requirements for the operation of all equipment in facility 100, operating limitations for all equipment in facility 100, including permissible rates of variation and minimum control ratios for downstream production process units 120, and hydrogen availability in hydrogen storage unit 112. When establishing one or more setpoints 131, ARC130 may also consider one or more non-facility-specific pieces of information 142, such as energy availability from the second energy source 20, hydrogen availability from the direct second hydrogen feed 115, and requirements for downstream production process units 120.

[0080] The ARC130 can also resolve any dynamic mismatch between the predicted energy curve and the actual amount of renewable energy available, which could cause hydrogen storage unit pressure or equipment operation to violate downstream acceptable limits.

[0081] In this embodiment, system 150 is used in conjunction with an appropriate advanced process control strategy. In this embodiment, ARC 130 receives one or more outputs from system 150 to establish one or more setpoints 131. For example, ARC 130 may receive, via 152, an operating target for the hydrogen flow rate of hydrogen feed 116 determined by system 150. In this embodiment, ARC 130 may generate one or more setpoints 131 based on the hydrogen flow rate target for hydrogen feed 116 received from system 150, to be transmitted to a distributed control system (hereinafter referred to as DCS) 160 for controlling downstream production process unit 120. In this embodiment, ARC 130 may predict whether the operating target for hydrogen flow rate determined by system 150 violates any downstream process operating limits. If no operating limits are violated, ARC 130 may use the operating target value transmitted at 152 as a setpoint and transmit it as 131 to DCS 160. If ARC130 determines that the hydrogen flow target value determined by system 150 violates the downstream process operating limits, ARC130 can adjust the hydrogen flow target value by changing the setpoint of the controller of the downstream production process unit 120, and can generate an appropriate corrected target setpoint as 131, which is then transmitted to the DCS160 of the downstream production process unit 120. Conversely, DCS160 can send a control signal 161 to the downstream production process unit 120.

[0082] In one embodiment, the output of system 150 is transmitted to the device operator via 151 to user interface 170. In another embodiment, the output of system 150 can be used as an operational target value for the green hydrogen flow rate to the hydrogen feed 116 to the downstream production process unit 120. In yet another embodiment, the operator can manually transmit setpoints and / or setpoint adjustments regarding the hydrogen flow rate to the downstream production process unit 120 via user interface 171 to DCS 160. In turn, DCS 160 can send control signals 161 to the downstream production process unit 120.

[0083] In this embodiment, system 150 is configured to further stabilize the operating load of downstream production process unit 120 by making minimal adjustments to the hydrogen flow rate, while also taking into account the current and future values ​​of renewable energy (based on weather forecasts) and the hydrogen inventory in the storage tanks required to operate within the permissible operating pressure range.

[0084] In one embodiment, system 150 predicts the magnitude of change required for the target net hydrogen flow rate of hydrogen feed 116, which will help stabilize the operation of downstream production process unit 120, even as renewable energy sources dynamically change due to weather variations and day-night cycles.

[0085] In some embodiments, facility 100 may use a second energy source 20. The second energy source 20 may include the power grid. It should be noted that any surplus electricity generated by the low-carbon energy source 10 may be fed to the power grid via energy connection 14. The second energy source 20 may also include a battery pack charged by the low-carbon energy source 10 and / or the power grid via energy connection 24. As described above, in some cases, facility 100 may use a second hydrogen source 30. When present, the second hydrogen source 30 may provide supplemental hydrogen feed to downstream production process unit 120. This supplemental hydrogen feed may replace or supplement the supplemental hydrogen supply line 114 from hydrogen storage unit 112. It should be noted that any surplus hydrogen generated by hydrogen source 111 or other hydrogen production equipment may be supplied to the second hydrogen source 30 via second hydrogen feed 33 or some other fluid line. ARC130 may adjust the use of energy from the second energy source 20 and the use of hydrogen from the second hydrogen source 30 according to the low-carbon energy availability curve and the hydrogen production of hydrogen source 111.

[0086] As discussed above, non-facility-specific information 142 may be associated with one or more environmental parameters. In this embodiment, system 150 also receives facility-specific information 141. Facility-specific information 141 may be associated with the operating parameters discussed above.

[0087] It should be noted that the above-described equipment, apparatus, components, and systems are merely examples of equipment, apparatus, components, and systems designed and configured to perform their respective tasks. For example, an electrolyzer is only one example of an apparatus that can be used to produce hydrogen. Other hydrogen sources may include renewable liquid reforming, high-temperature water splitting, photobiological water splitting, photoelectrochemical water splitting, etc. Therefore, the current teachings are not limited to the above-described equipment, apparatus, components, and systems, nor to the methods used therein.

[0088] As used in this article, the term "low-carbon energy" refers to energy sources that do not use hydrocarbons as their primary energy source. Examples of low-carbon energy include, but are not limited to, solar, wind, tidal, geothermal, hydroelectric, nuclear, and hydrogen energy. It should be noted that the term "low-carbon energy" encompasses energy sources that emit no carbon whatsoever, i.e., "zero-carbon energy."

[0089] The terms “comprising” and “comprises” used throughout the claims should be interpreted as “including but not limited to” and “includes but not limited to”, respectively.

[0090] As used in this article, the word “basically” should mean “mostly but not entirely”.

[0091] As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0092] For the purposes of this document, the term “about” when referring to a given parameter includes a specified value and has a meaning determined by the context (e.g., it includes the degree of error associated with the measurement of the given parameter).

[0093] For the purposes of this document, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0094] The foregoing description pertains to specific embodiments of the present disclosure and is for illustrative and explanatory purposes. However, it will be apparent to those skilled in the art that various modifications and variations can be made to the above embodiments without departing from the scope of this disclosure. The following claims are intended to be construed as covering all such modifications and variations.

Claims

1. A method for stabilizing the flow rate of hydrogen reaching downstream processes in a facility including a hydrogen storage unit and powered by low-carbon energy, the method comprising: For different target net hydrogen flow rates at different time intervals within the time range of the renewable energy availability curve, determine the hydrogen density and pressure curves in the hydrogen storage unit; For a given time interval within the time range, a first target net hydrogen flow rate is determined to reach the downstream process, wherein the first target net hydrogen flow rate corresponds to the maximum time required for the hydrogen pressure in the hydrogen storage unit to exceed the high pressure limit or low pressure limit. For a given time interval within the time range, a second target net hydrogen flow rate is determined to reach the downstream process, wherein the second target net hydrogen flow rate corresponds to the pressure curve of the hydrogen storage unit that deviates from the safety limit. The larger of the first target net hydrogen flow rate and the second target net hydrogen flow rate is set as the operating target net hydrogen flow rate; as well as The operation of downstream processes is controlled based on the net hydrogen flow rate of the stated operating target.

2. The method of claim 1, wherein determining the hydrogen density and pressure curves in the hydrogen storage unit for different target net hydrogen flows at different time intervals within the time range of the renewable energy availability curve comprises: Determine the mass of hydrogen produced in each time interval throughout the entire time range; Determine the relationship between the pressure and density of hydrogen in the hydrogen storage unit; Determine the hydrogen density in the hydrogen storage unit for each target net hydrogen flow rate at each time interval of the time range; as well as Determine the pressure profile of the hydrogen storage unit for each time interval within the specified time range.

3. The method of claim 1, wherein controlling the operation of the downstream process based on the target net hydrogen flow rate includes sending the target net hydrogen flow rate to an advanced regulation and control system, a user interface, or both.

4. The method of claim 1, wherein the downstream process comprises ammonia synthesis or methanol synthesis.

5. A system for stabilizing the flow rate of hydrogen to downstream processes in a facility including a hydrogen storage unit and powered by low-carbon energy, the system comprising: A non-transitory computer-readable medium storing computer-readable instructions thereon, which, when executed by a processor, cause the processor to: For different target net hydrogen flow rates at different time intervals within the time range of the renewable energy availability curve, determine the hydrogen density and pressure curves in the hydrogen storage unit; For a given time interval within the time range, a first target net hydrogen flow rate is determined to reach the downstream process, wherein the first target net hydrogen flow rate corresponds to the maximum time required for the hydrogen pressure in the hydrogen storage unit to exceed the high pressure limit or low pressure limit. For a given time interval within the time range, a second target net hydrogen flow rate is determined to reach the downstream process, wherein the second target net hydrogen flow rate corresponds to the pressure curve of the hydrogen storage unit that deviates from the safety limit. The larger of the first target net hydrogen flow rate and the second target net hydrogen flow rate is set as the operating target net hydrogen flow rate; as well as The target net hydrogen flow rate is used to control the operation of downstream processes.

6. The system of claim 5, wherein determining the hydrogen density and pressure curves in the hydrogen storage unit for different target net hydrogen flow rates at different time intervals within the time range of the renewable energy availability curve comprises: Determine the mass of hydrogen produced in each time interval throughout the entire time range; Determine the relationship between the pressure and density of hydrogen in the hydrogen storage unit; Determine the hydrogen density in the hydrogen storage unit for each target net hydrogen flow rate at each time interval of the time range; as well as Determine the pressure profile of the hydrogen storage unit for each time interval within the specified time range.

7. The system of claim 5, wherein controlling the operation of the downstream process based on the target net hydrogen flow rate includes sending the target net hydrogen flow rate to an advanced regulation and control system, a user interface, or both.

8. The system of claim 5, wherein the downstream process comprises ammonia synthesis or methanol synthesis.

9. A method for producing a product using low-carbon energy, the product being produced by a facility having downstream production process units, the method comprising: Energy is supplied to the facility, wherein at least a portion of the supplied energy comes from low-carbon energy that depends on at least one environmental parameter; The energy availability of the low-carbon energy source during the selected time period is assessed using at least one of the environmental parameters. The hydrogen feed to the downstream production unit is formed using at least one of the following: (i) The main hydrogen feedstock generated by the hydrogen source powered by the aforementioned low-carbon energy source, and (ii) Supplement hydrogen feed; The formation of the hydrogen feed is controlled using an advanced regulation controller (ARC), which is configured to generate a setpoint for the hydrogen feed using the assessed energy availability; as well as The product is produced by feeding the generated hydrogen gas into the downstream production unit. The method described in claim 1 ensures that the hydrogen feed gas reaches the downstream production process unit stably.

10. The method of claim 9, wherein the product is ammonia or methanol.

11. A facility using low-carbon energy, the facility comprising: Downstream production process units; Low-carbon energy that depends on at least one environmental parameter; A hydrogen source powered by the aforementioned low-carbon energy; A hydrogen storage unit arranged to receive hydrogen from the hydrogen source; Hydrogen feed that reaches the downstream production process unit and is fluidly connected to the hydrogen storage unit; A system for stabilizing the flow rate of hydrogen reaching downstream processes; and Product output, The system used to stabilize the hydrogen flow rate is configured as follows: For different target net hydrogen flow rates at different time intervals within the time range of the renewable energy availability curve, determine the hydrogen density and pressure curves in the hydrogen storage unit; For a given time interval within the time range, a first target net hydrogen flow rate is determined to reach the downstream process, wherein the first target net hydrogen flow rate corresponds to the maximum time required for the hydrogen pressure in the hydrogen storage unit to exceed the high pressure limit or low pressure limit. For a given time interval within the time range, a second target net hydrogen flow rate is determined to reach the downstream process, wherein the second target net hydrogen flow rate corresponds to the pressure curve of the hydrogen storage unit that deviates from the safety limit. The larger of the first target net hydrogen flow rate and the second target net hydrogen flow rate is set as the operating target net hydrogen flow rate; as well as The target net hydrogen flow rate is used to control the operation of downstream processes.

12. The facility of claim 11, wherein the downstream production process unit comprises an ammonia synthesis unit or a methanol synthesis unit.

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