Plant operation support system

Abstract

To maximize a value of a plant's product when operating a plant with a water electrolysis facility and a water treatment facility.SOLUTION: A plant operation support device 1 for a plant 5 having a water treatment facility and a water electrolysis facility using recycled water generated by the water treatment facility, includes: a measurement unit 11 that monitors an operation status of the water treatment facility and the water electrolysis facility; an internal value calculation means 12 for calculating a value in a case where a product of the water treatment facility or the water electrolysis facility is used inside the plant based on monitoring information of the measurement unit; external value calculation means 13 for calculating a value in a case where the product of the water treatment facility or the water electrolysis facility is used outside the plant; and operation condition planning means 14 for planning operation conditions of the water treatment facility and the water electrolysis facility based on the calculation results of the internal value calculation means and the external value calculation means, and providing the operation conditions to the water treatment facility and the water electrolysis facility.SELECTED DRAWING: Figure 1

Description

Technical Field

[0006] , , ,

[0001] The present invention relates to a plant operation support device for a plant having a water electrolysis facility and a water treatment facility.

Background Art

[0002] As the negative impacts of greenhouse gases become apparent, the shift towards a decarbonized society to avoid them is progressing rapidly. In a decarbonized society, it is considered that the shift will progress from energy that depends on conventional fossil fuels to renewable energy such as sunlight and wind power. In addition, as an energy source to replace fossil fuels, attention has been focused on green hydrogen produced by renewable energy.

[0003] A water electrolysis facility that produces green hydrogen consumes renewable electricity and water as a raw material. Arid regions with a large abundance of renewable energy such as sunlight and wind are regions with water shortages, that is, regions with high water stress, and the water supply source may become a problem. For this reason, it has been considered to install a water electrolysis facility and a water treatment facility together, recycle wastewater as recycled water in the water treatment facility, and use it as a water supply source for water electrolysis.

[0004] As a technology related to a plant having a water electrolysis facility and a water treatment facility, there is the disclosed technology of Patent Document 1. Specifically, in Patent Document 1, it is described that oxygen, which is a by-product of a water electrolysis facility, is used as an alternative raw material for air supplied by a blower for microbial treatment in a water treatment facility.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As described in Patent Document 1, water electrolysis equipment produces not only hydrogen but also oxygen. This oxygen can be converted into ozone by discharge or electrolysis, and can therefore be supplied as an oxygen raw material outside of a plant that has water electrolysis equipment and water treatment equipment. Patent Document 1 only discloses the consumption of oxygen produced by water electrolysis equipment within the plant, and does not describe the use of oxygen outside the plant.

[0007] The objective of the present invention is to provide a plant operation support device that maximizes the value of the plant's products when operating a plant having water electrolysis equipment and water treatment equipment. [Means for solving the problem]

[0008] To solve the aforementioned problems, the plant operation support device for a plant having a water treatment facility and a water electrolysis facility that uses recycled water produced by the water treatment facility comprises: a measurement unit that monitors the operating status of the water treatment facility and the water electrolysis facility; an internal value calculation means that calculates the value of the products of the water treatment facility or the water electrolysis facility when used inside the plant based on the monitoring information of the measurement unit; an external value calculation means that calculates the value of the products of the water treatment facility or the water electrolysis facility when used outside the plant; and an operating condition planning means that plans the operating conditions of the water treatment facility and the water electrolysis facility based on the calculation results of the internal value calculation means and the external value calculation means, and provides the operating conditions to the water treatment facility and the water electrolysis facility. [Effects of the Invention]

[0009] According to the present invention, in a plant having a water treatment device and a water electrolysis device, the value of the plant's products can be maximized. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram showing the plant operation support system and the plant configuration of Example 1. [Figure 2] This diagram shows the flow of products from the plant in Example 1. [Figure 3] It is a diagram showing the temporal changes of external usage traffic and internal usage traffic. [Figure 4] It is a diagram showing an example of the temporal variation of the total value of oxygen O2. [Figure 5A] It is a diagram showing an example of the relationship between the function for calculating the internal value of oxygen O2 and the internal usage traffic. [Figure 5B] It is a diagram showing another example of the relationship between the function for calculating the internal value of oxygen O2 and the internal usage traffic. [Figure 6A] It is a diagram showing an example of the transition of internal value, external value, and total value. [Figure 6B] It is a diagram showing an example of the transition of internal value, external value, and total value. [Figure 6C] It is a diagram showing an example of the transition of internal value, external value, and total value. [Figure 7] It is a diagram showing the product flow of the plant of Example 2. [Figure 8] It is a configuration diagram of the plant operation support device of Example 3 and the plant. [Figure 9] It is a diagram showing the product flow of the plant of Example 3. [Figure 10] It is a diagram showing the product flow of the plant of Example 4. [Figure 11] It is a configuration diagram of the plant operation support device of Example 5 and the plant. [Figure 12] It is a diagram showing the product flow of the plant of Example 5.

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Examples

[0012] FIG. 1 is a configuration diagram of the plant operation support device 1 of the embodiment and the plant 5 to which the plant operation support device 1 is applied. The plant 5 (dashed frame in FIG. 1) to which the plant operation support device 1 of the present embodiment is applied has a water treatment facility 2 and a water electrolysis facility 3, and supplies the respective products (reclaimed water, hydrogen H2, oxygen O2) to the outside 4 of the plant.

[0013] The plant operation support device 1 includes a measurement unit 11 that monitors the operation status of the water treatment facility 2 and the water electrolysis facility 3, an internal value calculation means 12 that calculates the value when the product of the water treatment facility 2 or the water electrolysis facility 3 is used inside the plant based on the monitoring information of the measurement unit 11, an external value calculation means 13 that calculates the value when the product of the water treatment facility 2 or the water electrolysis facility 3 is used outside the plant 4, and an operation condition planning means 14 that plans the operation conditions of the water treatment facility 2 and the water electrolysis facility 3 based on the calculation results of the internal value calculation means 12 and the external value calculation means 13 and provides them to the water treatment facility 2 and the water electrolysis facility 3.

[0014] Specifically, the plant operation support device 1 is constituted by a computer (information processing device) including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a storage device such as an HDD (hard disk drive), and a display. Then, when the CPU executes the program stored in the HDD, the measurement unit 11, the internal value calculation means 12, the external value calculation means 13, and the operation condition planning means 14 function.

[0015] FIG. 2 is a diagram showing the flow of the products of the plant 5 in FIG. 1. The description of hydrogen H2, which is the product of the water electrolysis facility 3, is omitted. The water treatment facility 2 treats wastewater with microorganisms to generate reclaimed water H2O and supplies it to the water electrolysis facility 3. At this time, oxygen O2 is supplied from the water electrolysis facility 3 to the water treatment facility 2 and used for the microbial treatment of wastewater.

[0016] The water electrolysis equipment 3 produces hydrogen (H2) and oxygen (O2) by electrolyzing water, i.e., by electrolyzing reclaimed water (H2O). Generally, the water electrolysis equipment 3 is a device that produces hydrogen (H2), with oxygen (O2) being a by-product. This oxygen (O2) can be supplied to the outside of the plant 4, or, as described above, supplied to the water treatment equipment 2 for use inside the plant. Furthermore, the oxygen (O2) can be utilized both inside and outside the plant in predetermined proportions.

[0017] More specifically, oxygen (O2), a by-product of the water electrolysis equipment (3), can be sold as oxygen gas to external parties (4) outside the plant. Therefore, the external value of oxygen (O2) is converted into a sales price. Sales methods include processing to a certain quality and selling in cylinders, or selling via pipeline to another plant on the same site. Sales prices vary depending on the application (medical, industrial, environmental remediation, etc.) and depend on the contract and market price. Furthermore, the value of the product may be measured not only in economic terms but also in terms of quantitative values ​​from an environmental perspective.

[0018] When oxygen (O2), a by-product of water electrolysis equipment 3, is used in the microbial treatment of water treatment equipment 2, the microorganisms respire oxygen. Therefore, by supplying oxygen (O2) with a higher oxygen concentration than air, the amount of air supplied by the blower to the microbial reaction tank can be reduced. In other words, the value of oxygen (O2) within the plant can be converted into a reduction in blower power consumption.

[0019] The following describes how to calculate the intrinsic and extrinsic value of oxygen (O2), a by-product of water electrolysis equipment 3.

[0020] If we define internal utilization form 1 as the oxygen O2, a by-product of the water electrolysis equipment 3, being supplied to the water treatment equipment 2 and mixed with the air in the blower for use, and external utilization form 1 as the form in which it is sold to an external party 4, and if we define the utilization rate of oxygen O2 in external utilization form 1 (external utilization rate) as Q_out,1 (hereinafter, subscripts are indicated from _ onwards) and the utilization rate of oxygen O2 in internal utilization form 1 (internal utilization rate) as Q_in,1, then the total flow rate of oxygen O2 produced by the water electrolysis equipment 3, Q_total,O2, is given by the following equation (1).

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[0021] The above-mentioned utilization flow rate is a value related to the operating conditions of Plant 5, and in this embodiment, the external utilization flow rate and internal utilization flow rate are determined for the allocation that maximizes the sum of external value and internal value. Figure 3 shows the time evolution of external and internal utilization flow rates. External utilization flow rate Q_out,1 and internal utilization flow rate Q_in,1 change continuously or discontinuously depending on the plant's operating conditions, equipment constraints, and contract type.

[0022] Furthermore, if we denote the function representing the intrinsic value of oxygen O2, a by-product of water electrolysis equipment 3, as e_in (hereinafter, the subscript will be denoted from _), and the function representing the external value as e_out, then e_total, which represents the total value of oxygen O2, is the cost function shown in the following equation (2).

number

[0023] Figure 4 shows an example of the time variation of e_total, which represents the total value of oxygen O2. There are times when the internal value e_in is 0 and times when the external value e_out is 0, and the plant operation support device 1 plans the plant operating conditions that maximize e_total, which represents the total value, over the entire elapsed time.

[0024] Let Q_in,n be the internal utilization flow rate of oxygen O2 in a certain internal utilization mode n, and let f_in,n(Q_in,n) be the function used to calculate the internal value of oxygen O2 at this time. Then the sum of the internal values ​​from internal utilization modes 1 to n is the internal value e_in, which is given by the following equation (3).

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[0025] Let Q_out,m be the external utilization flow rate of oxygen O2 in a certain external utilization mode m, and let f_out,m(Q_out,m) be the function used to calculate the external value of oxygen O2 at this time. Then the sum of the internal values ​​from external utilization modes 1 to m is the internal value e_out, which is shown by the following equation (4).

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[0026] The plant operation support device 1 formulates a function f_in,n(Q_in,n) for calculating internal value using the internal value calculation means 12 (see Figure 1), and formulates a function f_out,m(Q_out,m) for calculating external value using the external value calculation means 13 (see Figure 1). The operation condition planning means 14 (see Figure 1) plans the operation conditions, such as the oxygen O2 utilization flow rate, its distribution ratio, and the operation amounts of each device based on these, so as to maximize e_total, which represents the total value.

[0027] The operating condition planning means 14 may plan operating conditions such as the oxygen utilization flow rate, its distribution ratio, and the amount of operation for each device based thereon, so as to maximize e_total, which includes future value.

[0028] The following describes the function for calculating intrinsic value. In the following, we will explain the case where n=1, and oxygen O2 is used internally in the microbial reaction tank of water treatment facility 2, and the case where m=1, and oxygen O2 is sold externally, using Figures 5A and 5B.

[0029] Figure 5A shows an example of the relationship between the function f_in,1 for calculating the internal value of oxygen O2 and the internal utilization flow rate Q_in,1 of oxygen O2. In the microbial reaction tank of water treatment facility 2, air is supplied by a blower, so electricity costs are incurred depending on the air supply flow rate.

[0030] Microorganisms take in oxygen to treat wastewater, and since oxygen (O2) has a higher oxygen concentration than air, the blower's supply flow rate can be reduced. In other words, when the internal utilization flow rate of oxygen (O2) Q_in,1 is 0, the function f_in,1 for calculating the internal value is 0. As the internal utilization flow rate Q_in,1 increases, the value of the function f_in,1 which is converted into a reduction in blower power consumption increases, and the internal value e_in of oxygen (O2) also increases.

[0031] If the required oxygen flow rate for the microbial reaction vessel is secured, supplying any additional oxygen (O2) will not allow the microorganisms to take in oxygen, so there is no effect on reducing the power consumption of the blower, the value of the function f_in,1 remains constant, and the internal value of oxygen (O2) e_in also remains constant.

[0032] Figure 5B shows another example where the relationship between the function f_in,1 for calculating the internal value of oxygen O2 and the internal utilization flow rate Q_in,1 of oxygen O2 is nonlinear and discontinuous. Specifically, if the number or combination of blowers changes depending on the required oxygen flow rate of the microbial reaction tank, the value of the function f_in,1 used to calculate the internal value will be discontinuous. Furthermore, if a flow rate exceeding the required oxygen flow rate is handled, the processing may incur additional costs. In such cases, as shown in Figure 5B, the value of the function f_in,1 used to calculate the internal value will decrease.

[0033] The following explains the changes in internal value e_in, external value e_out, and total value e_total in cases where oxygen O2 is used internally and sold externally, etc., using Figures 6A, 6B, and 6C.

[0034] In Figures 6A, 6B, and 6C, the left end of the graph shows the case where Q_in,1 is equal to Q_total and all is used internally (100% allocation to internal use flow), and the right end shows the case where Q_out,1 is equal to Q_total and all is used externally (100% allocation to external use flow).

[0035] As explained in detail below, conceptually, the internal value e_in and external value e_out increase in proportion to the flow rate, and the value becomes zero when the upper limit is exceeded (for example, when the flow rate exceeds the required flow rate in the microbial reaction vessel or exceeds the upper limit of the contracted sales volume).

[0036] Figure 6A shows a case where there are no upper limits on the internal value e_in and external value e_out, and the value per unit flow rate is higher in terms of external value. The maximum total value e_total is at the far right, i.e., when all the oxygen O2 is sold externally.

[0037] Figure 6B shows the case where the selling price to external parties has decreased. In this case, the maximum total value e_total is at the far left, i.e., when all oxygen O2 is used internally.

[0038] Figure 6C shows a case where, as the amount of renewable energy supplied to the water electrolysis equipment 3 increases, the amount of oxygen (O2), a by-product, produced also increases, resulting in the upper limit for internal use (the required flow rate in the microbial reaction tank) exceeding the upper limit for external use (the contracted sales volume). In this example, the total value e_total is maximized at the distribution point where the upper limit for external use is reached.

[0039] In the above, a graph of a function that calculates the internal value, which increases linearly and remains constant, was shown for illustrative purposes. However, the shape of the function f_in,n that calculates the internal value changes depending on the fluctuating wastewater treatment flow rate of the water treatment facility 2, the operating point and number of blowers according to the performance curve, the gas temperature, the method of supplying oxygen O2 (such as mixing it with air when introducing it into the microbial reaction tank, or introducing it in a separate system from the air), and whether or not the gas after aeration is recovered and reused. Furthermore, since the shape of the functions f_in,n used to calculate the internal value differs depending on the specifications of the blower, even in the case of applying oxygen O2 to microbial treatment, multiple functions must be summed to calculate the internal value e_in.

[0040] Furthermore, electricity costs vary depending on the amount, time, and contract type of electricity used. Also, in some cases, using renewable energy sources may increase the value compared to using fossil fuel-derived electricity. The function f_in,n for calculating internal value is created in either a functional or tabular form, taking these factors into account.

[0041] The external value calculation functions f_out,m should also be created in either a function or tabular format, taking into account factors such as market conditions, contract details, required flow rate, quality of supplied valuables, and time fluctuations.

[0042] In the above, we explained how to distribute and utilize oxygen O2, a by-product of water electrolysis equipment 3, when it is used externally and internally in water treatment equipment 2. However, if there are multiple products to be distributed and utilized, multiple destinations for the products, and multiple pieces of equipment and conditions, then the functions f_in,n for calculating the internal value and f_out,m for calculating the external value will be multiple accordingly, and as shown in equations (3) and (4), the internal value e_in and the external value e_out will be the sum of multiple functions.

[0043] In cases where the range of possible operation changes depending on the event, such as equipment failure, production schedule changes, or periodic maintenance requiring the shutdown of some equipment, a simple summation may not be possible. However, even in such cases, it is acceptable to express the value corresponding to the event functionally and evaluate it as an additive value, or to express the presence or absence and quantification of the value corresponding to the event using a conditional branching expression and evaluate it as an additive value according to the conditional branching.

[0044] The internal utilization flow rate Q_in,n and external utilization flow rate Q_out,m of the above-mentioned by-product oxygen O2 can be not only the flow rate of the plant in operation, but also the planned flow rate or required flow rate of the plant, which are information that will occur in the future, as long as it is information that will also change over time.

[0045] The plant operation support system 1 performs optimization calculations to maximize the cost function based on the relational equations derived from the formalized equations (1) to (4) when determining the operating conditions.

[0046] Optimization methods include the simplex method for linear programming problems, the interior-point method, the effective constraint method for convex quadratic programming problems, the steepest descent method for unconstrained nonlinear programming problems, Newton's method, quasi-Newton's method, the penalty function method for constrained nonlinear programming problems, the extended Lagrangian function method, the interior-point method, successive quadratic programming, the greedy method for resource allocation problems and minimum spanning tree problems, the knapsack problem, the resource allocation problem, dynamic programming for minimum cost elastic matching problems, Dijkstra's algorithm for shortest path problems, Bellman-Ford method, and Floyd Warshaw. Any method applicable to optimization problems is acceptable, including methods other than those listed above, such as the Lu method, increasing path method, negative cycle elimination method, shortest path iteration method, Hungarian method for maximum flow problems, minimum cost flow problems, maximum matching problems, allocation problems, etc.; branch and bound method for integer progression problems, cut plane method, branch cut method; performance-guaranteed approximate solution methods for bin packing problems, maximum cut problems, traveling salesman problem, vertex cover problem, knapsack problem, etc.; heuristic solution methods for NP-hard problems, local search methods, metaheuristics, branch cut method, etc.

[0047] The plant operation support device 1 is equipped with display means (not shown) and may display graphs such as Figures 3, 4, 5A, 5B, 6A, 6B, and 6C, values ​​for internal and external values ​​at a certain time, and tables similar to graphs. [Examples]

[0048] Figure 7 shows the flow of products in plant 5 to which the plant operation support device 1 of this embodiment is applied. Note that the products of the water electrolysis equipment 3 are not described. Water treatment equipment 2 treats wastewater with microorganisms to produce reclaimed water H2O, supplies the reclaimed water H2O as effluent to the outside of the plant 4, and also supplies the reclaimed water H2O to water electrolysis equipment 3. Water electrolysis equipment 3 generates hydrogen (H2) and oxygen (O2) by electrolyzing water, that is, by electrolyzing recycled water (H2O).

[0049] In Example 1, we described a case where oxygen O2, a product of the water electrolysis equipment 3, is used internally in the water treatment equipment 2 of Plant 5. In Example 2, we will describe a case where reclaimed water H2O, a product of the water treatment equipment 2, is used internally in the water electrolysis equipment 3 of Plant 5.

[0050] The configuration of the plant operation support device 1 in this embodiment is the same as the configuration diagram in Figure 1, and therefore, a detailed explanation is omitted here. Furthermore, the plant operation support device 1, as described above, formulates a function f_in,n(Q_in,n) for calculating internal value using the internal value calculation means 12 (see Figure 1), and formulates a function f_out,m(Q_out,m) for calculating external value using the external value calculation means 13 (see Figure 1). The operation condition planning means 14 (see Figure 1) then plans the operation conditions, such as the manipulated amounts of each device, so as to maximize e_total, which represents the total value.

[0051] The following describes the examples in more detail. In Example 1, the internal value of oxygen (O2) was explained as being converted into the amount of electricity saved by the blower supplying air to the microbial reaction tank. In Example 2, however, the internal value of the recycled water (H2O) supplied to the water electrolysis equipment 3 is converted into the cost savings of water from other sources, such as tap water, that was previously supplied to the water electrolysis equipment 3. The external value of the recycled water (H2O) produced by the water treatment equipment 2 is calculated as blue carbon related to carbon sequestration in marine ecosystems using an external value calculation method.

[0052] Furthermore, in equations (1) to (4) of Example 1, and in Figures 6A, 6B, and 6C, oxygen O2 can be replaced with recycled water H2O.

[0053] Applying Figure 6A to Example 2, Figure 6A represents a case where there is no upper limit and the value per unit flow rate is high in terms of external value. The maximum total value e_total is at the far right, for example, when all of the recycled water H2O is sold externally.

[0054] Applying Figure 6B to Example 2, Figure 6B represents a case where the value of recycled water H2O within the plant is enhanced. In addition to recycled water H2O in this example, water can be supplied to the water electrolysis equipment 3 from various sources, such as tap water, groundwater, river water, and rainwater. However, during droughts, tap water competes with domestic water use, so reducing its use contributes to improving social value and thus enhances the value of recycled water. In this case, the maximum total value e_total is represented on the far left, i.e., when all recycled water H2O is used internally, reducing the purchase of tap water, etc.

[0055] Applying Figure 6C to Example 2, Figure 6C illustrates a case where the upper limit for internal use of recycled water H2O (the upper limit for recycled water H2O supplied from water treatment facility 2 or the maximum required amount of recycled water H2O at water electrolysis facility 3) exceeds the upper limit for external use (for example, the recycled water utilization rate predetermined by ordinances, etc.). In this case, the total value e_total is maximized at the distribution point where the upper limit for external use is reached.

[0056] In this embodiment, external use refers to the sale of recycled water H2O from the water treatment facility 2 to an external party 4. This sale may involve processing the water to a certain quality level and selling it in tanks or bottles, or it may involve supplying it via pipeline to another plant on the same site. Furthermore, the uses are diverse, including water for surrounding parks, washing, domestic use, agricultural use, medical use, industrial use, and environmental purification. Therefore, the selling price will fluctuate depending on the contract and market price.

[0057] Furthermore, although this embodiment describes selling the reclaimed water H2O to an external party, it may also be discharged as effluent to an external party. When transferring the reclaimed water H2O to an external party 4, it may be discharged into rivers or the sea without investing energy to improve the water quality to that of reclaimed water.

[0058] In this case, compared to the internal use of recycled water H2O, the amount of energy input is smaller, costs can be reduced, and the external value for external use can be improved. Furthermore, by optimizing the volume and quality (organic matter, nitrogen, phosphorus, etc.) of recycled water H2O (effluent) before discharge, it is possible to contribute to biodiversity, a richer ocean (recreation, tourism, fisheries, reduction of red tides and blue tides, etc.), and an increase in blue carbon, which represents carbon sequestration from marine ecosystems. These can be used to calculate the total value by creating functions and tables corresponding to the water quality and volume discharged as external value.

[0059] In this embodiment, we have described the case in which the reclaimed water H2O from the water treatment facility 2 is allocated for external use and for internal use in the water electrolysis facility 3. However, if there are multiple products to be allocated and used, multiple sales destinations for the products, and multiple pieces of equipment and conditions, then the functions f_in,n for calculating the internal value and f_out,m for calculating the external value will be multiple accordingly, and as shown in equations (3) and (4), the internal value e_in and the external value e_out will be the sum of the values ​​of multiple functions.

[0060] When equipment is partially shut down due to equipment failure, production schedule changes, or periodic maintenance, or when considering natural environmental conditions such as water shortages or deterioration of discharge areas, the possible operating range may change depending on the event, and a simple addition may not be possible. In such cases, however, the value corresponding to the event can be expressed functionally and evaluated by adding the values, or a conditional branching formula can be used to express the presence or absence and quantification of the value corresponding to the event, and evaluated by adding the values ​​according to the conditional branching.

[0061] In Example 1, the case in which oxygen O2 from the water electrolysis equipment 3 is used both externally and internally in the water treatment equipment 2 was described, and in Example 2, the case in which reclaimed water H2O from the water treatment equipment 2 is used both externally and internally in the water electrolysis equipment 3 was described. However, the oxygen O2 from the water electrolysis equipment 3 and the reclaimed water H2O from the water treatment equipment 2 may be used internally and externally, respectively. [Examples]

[0062] Figure 8 shows the configuration of the plant operation support device 1 of the embodiment and the plant 5 to which the plant operation support device 1 is applied. The plant 5 (dashed line frame in Figure 5) to which the plant operation support device 1 of this embodiment is applied has a water treatment facility 2, a water electrolysis facility 3, and a sludge treatment facility 6, and supplies the products of each (reclaimed water, biogas CH4, hydrogen H2, and oxygen O2) to the outside of the plant 4.

[0063] The plant operation support device 1 includes a measurement unit 11 that monitors the operating status of the water treatment facility 2, the water electrolysis facility 3, and the sludge treatment facility 6; an internal value calculation means 12 that calculates the value of the products of the water treatment facility 2, the water electrolysis facility 3, and the sludge treatment facility 6 if they were used inside the plant based on the monitoring information from the measurement unit 11; an external value calculation means 13 that calculates the value of the products of the water treatment facility 2, the water electrolysis facility 3, and the sludge treatment facility 6 if they were used outside the plant 4 based on information from outside the plant 4; and an operating condition planning means 14 that plans the operating conditions of the water treatment facility 2, the water electrolysis facility 3, and the sludge treatment facility 6 based on the calculation results of the internal value calculation means 12 and the external value calculation means 13, and provides them to the water treatment facility 2, the water electrolysis facility 3, and the sludge treatment facility 6.

[0064] Sludge treatment facility 6 is a facility that treats activated sludge C (microorganisms) that have been proliferated and separated during microbial treatment in water treatment facility 2. The microorganisms that have proliferated using organic matter in the wastewater as a carbon source are subjected to anaerobic fermentation in the digester of sludge treatment facility 6, producing biogas CH4 (a mixed gas of CH4 and CO2).

[0065] Activated sludge C, which is composed of microorganisms, contains some recalcitrant organic matter that is difficult to decompose through anaerobic fermentation. However, by applying highly oxidizing substances such as ozone, anaerobic fermentation becomes easier, increasing the rate and amount of biogas CH4 produced. This pretreatment is called solubilization treatment, and ozone is produced by electrolyzing oxygen. The oxygen used as a raw material can be purchased in cylinders or obtained by concentrating and producing it from air using concentration equipment such as membranes or pressure fluctuation adsorption methods.

[0066] Figure 9 shows the flow of products in plant 5 to which the plant operation support device 1 of the embodiment is applied. Note that the description of hydrogen H2, a product of the water electrolysis equipment 3, has been omitted.

[0067] Water treatment facility 2 treats wastewater with microorganisms to produce recycled water H2O, which is supplied to water electrolysis facility 3. It also separates the microorganisms that proliferate during microbial treatment to form activated sludge C, which is supplied to sludge treatment facility 6 (in Figure 9, activated sludge C is labeled "C (sludge)"). The sludge treatment facility 6 generates biogas CH4 through anaerobic fermentation of activated sludge C. Water electrolysis equipment 3 produces hydrogen (H2) and oxygen (O2) by electrolyzing water, that is, by electrolyzing recycled water (H2O). Generally speaking, water electrolysis equipment 3 is equipment that produces hydrogen (H2), and oxygen (O2) is a by-product.

[0068] The oxygen (O2) produced in the water electrolysis equipment 3, the biogas (CH4) produced in the sludge treatment equipment 6, and the recycled water (H2O) produced in the water treatment equipment 2 can be used in predetermined proportions both inside and outside the plant 5. Next, we will explain how the products are utilized both inside and outside Plant 5.

[0069] The biogas CH4 produced in the sludge treatment facility 6 can be used within the plant 5 by burning the biogas CH4 or generating electricity to heat the anaerobic fermentation tank in the sludge treatment facility 6, or to power the blowers and other equipment in the water treatment facility 2, and its internal use value can be calculated.

[0070] The oxygen (O2) produced in the water electrolysis equipment 3 is converted to ozone (O3) and used inside the plant 5. For example, the sludge treatment equipment 6 can convert oxygen (O2) to ozone (O3), and this ozone (O3) can be applied to the sludge solubilization process, which is a pretreatment for anaerobic fermentation in the sludge treatment equipment 6, thereby increasing the amount of biogas (CH4) produced in the sludge treatment equipment 6. The reduction in the amount of ozone (O3) purchased in the sludge treatment equipment 6 due to the internal use of oxygen (O2) is converted into the internal use value of oxygen (O2). Alternatively, the increase in biogas (CH4) in the sludge treatment equipment 6 may also be converted into the internal use value of oxygen (O2). Instead of converting oxygen (O2) to ozone (O3) inside the sludge treatment equipment 6, the oxygen (O2) may be converted to ozone (O3) in the water electrolysis equipment 3 and supplied to the sludge treatment equipment 6.

[0071] Furthermore, the oxygen (O2) produced in the water electrolysis equipment 3 can be used in the water treatment equipment 2 for accelerated oxidation treatment (treatment using hydrogen peroxide, ultraviolet light, ozone, photocatalysts, or combinations thereof) to remove recalcitrant organic matter, thereby improving the quality of the recycled water (H2O). In this case, the cost reduction of the accelerated oxidation treatment is converted into the internal utilization value of the oxygen (O2).

[0072] Biogas (CH4) or oxygen (O2) can be sold for external use outside the plant, and its value is converted through sales. Sales may involve processing the biogas to a certain quality and selling it in cylinders, or it may be sold via pipeline to another plant on the same site. It has various uses, including as fuel, for medical purposes, industrial purposes, and environmental remediation, but the selling price fluctuates depending on the contract and market price.

[0073] As described above, the plant operation support device 1 formulates a function f_in,n(Q_in,n) for calculating the internal value of oxygen O2, biogas CH4, and recycled water H2O using the internal value calculation means 12 (see Figure 8), and formulates a function f_out,m(Q_out,m) for calculating the external value of oxygen O2, biogas CH4, and recycled water H2O using the external value calculation means 13 (see Figure 8). The operation condition planning means 14 (see Figure 8) plans the operation conditions, such as the operation amounts of each device, so as to maximize e_total, which represents the total value.

[0074] Next, the changes in internal value e_in, external value e_out, and total value e_total when oxygen O2, a by-product of the water electrolysis equipment 3, is supplied to the sludge treatment equipment 6 as an internal use form, and also sold as an external use form, will be explained using Figures 6A, 6B, and 6C.

[0075] Applying Figure 6A to Example 3, Figure 6A represents a case where there is no upper limit and the value per unit flow rate is high in terms of external value. The maximum total value e_total is at the far right, when all of the oxygen O2 is sold externally.

[0076] Applying Figure 6B to Example 3, Figure 6B represents a case where the selling price of oxygen O2 to the outside decreases. Alternatively, it represents a case where the solubilization treatment of the internal sludge treatment facility 6 is increased, and as a result of increasing the amount of biogas CH4 produced, the internal value (the sale of biogas CH4 to the outside is also a result of the internal use of oxygen O2, so it is included in the value of the plant here) increases. In this case, the maximum total value e_total is on the far left, i.e., when all oxygen O2 is used internally.

[0077] Applying Figure 6C to Example 3, Figure 6C illustrates a case where, as the amount of renewable energy supplied to the water electrolysis equipment 3 increases, the amount of oxygen O2, a by-product, increases, resulting in the upper limit of internal use (the required flow rate for solubilization) exceeding the upper limit of external use (the contracted sales volume). In this case, the total value e_total is maximized at the distribution point where the upper limit of external use is reached.

[0078] In this embodiment, the internal utilization of oxygen O2 from the water electrolysis equipment 3 was described as conversion to ozone O3 for solubilization treatment in the sludge treatment equipment 6. However, it may also be used to reduce the costs of blower aeration and accelerated oxidation treatment in the water treatment equipment 2. Furthermore, other utilization methods described in other embodiments or other utilization methods may be used, or multiple utilization methods may be combined. When combining methods, the calculation of the internal value is performed by combining the utilization methods to be considered, as shown in equation (3).

[0079] In this embodiment, the external use of oxygen O2 from the water electrolysis equipment 3 was described as external sale. However, other external use forms may include the sale of biogas CH4 produced in the sludge treatment equipment 6 or recycled water H2O produced in the water treatment equipment 2. Furthermore, other use forms described in other embodiments or other forms may be used, or multiple use forms may be combined. When combining use forms, the calculation of the external value is performed by combining the use forms to be considered, as shown in equation (4).

[0080] In this embodiment, the activated sludge C produced in the water treatment facility 2 was subjected to digestion and fermentation treatment in the sludge treatment facility 6, but external organic matter (such as household food waste or processing residues) may also be used. In this case, the acceptance of external organic matter may be treated as one of the internal utilization methods to support the production of biogas CH4 in the sludge treatment facility 6, or as one of the external utilization methods. [Examples]

[0081] Next, we will explain the case in the configuration of Plant 5 in Example 3 where the activated sludge C in the sludge treatment facility 6 is a recalcitrant organic substance that is difficult to decompose through anaerobic fermentation. When the activated sludge C is a recalcitrant organic substance, heating the digester (to about 35 to 65 degrees Celsius) promotes fermentation, increasing the rate and amount of biogas CH4 produced in the sludge treatment facility 6. Normally, the heat required is supplied by burning fuel purchased from an external source or the biogas CH4 produced.

[0082] Example 4 describes a case in which the heat produced by the water electrolysis equipment 3 and the biogas CH4 produced by the sludge treatment equipment 6 are utilized within the plant 5, taking into consideration the allocation between external and external use. The configuration of the plant operation support device 1 and the plant 5 to which the plant operation support device 1 is applied in this embodiment is the same as in Figure 8, so a description will be omitted.

[0083] Figure 10 shows the flow of products in plant 5 to which the plant operation support device 1 of the embodiment is applied. Note that the description of hydrogen H2, a product of the water electrolysis equipment 3, has been omitted.

[0084] Water treatment facility 2 treats wastewater with microorganisms to produce recycled water H2O, which is supplied to water electrolysis facility 3. It also separates the microorganisms that proliferate during microbial treatment to produce activated sludge C, which is supplied to sludge treatment facility 6 (in Figure 10, activated sludge C is labeled "C (sludge)"). The sludge treatment facility 6 generates biogas CH4 through anaerobic fermentation of activated sludge C. Water electrolysis equipment 3 produces hydrogen (H2) and oxygen (O2) by electrolyzing water, i.e., by electrolyzing recycled water (H2O). In order to stably carry out the water electrolysis reaction, more power than theoretically necessary is applied. As a result, a large amount of Joule heat is generated.

[0085] One external use of the heat generated by the water electrolysis equipment 3 is, for example, to sell it for use in air conditioning or heating manufacturing processes outside of Plant 5. On the other hand, one internal use within Plant 5 is to use it for heating the anaerobic fermentation process in the sludge treatment equipment 6.

[0086] The cost savings in fuel expenses for the sludge treatment facility 6 due to this heating will be converted into the external or internal use value of the heat generated by the water electrolysis facility 3. In addition, the biogas CH4 increased by utilizing the heat generated by the water electrolysis facility 3 can be used for other purposes (sale to external parties, power generation, etc.), and the value generated therefrom will be converted into the internal use value of the heat generated by the water electrolysis facility 3.

[0087] Furthermore, when the biogas CH4 of the sludge treatment facility 6 is used internally, it can be used for heating the anaerobic fermentation tank of the sludge treatment facility 6 or for powering the blower of the water treatment facility 2 by burning or generating electricity from the biogas CH4, and the value generated by this is converted into the internal use value of the biogas CH4 of the sludge treatment facility 6.

[0088] As described above, the plant operation support device 1 formulates a function f_in,n(Q_in,n) in the internal value calculation means 12 (see Figure 8) to calculate the internal value of the heat produced by the water electrolysis equipment 3 and the biogas CH4 produced by the sludge treatment equipment 6, and formulates a function f_out,m(Q_out,m) in the external value calculation means 13 (see Figure 8) to calculate the external value of the heat and biogas CH4. The operation condition planning means 14 (see Figure 8) plans the operation conditions, such as the operating amounts of each device, so as to maximize e_total, which represents the total value.

[0089] Next, the changes in internal value e_in, external value e_out, and total value e_total when the heat produced by the water electrolysis equipment 3 is supplied to the sludge treatment equipment 6 as an internal use and also sold as an external use are explained using Figures 6A, 6B, and 6C.

[0090] Applying Figure 6A to Example 4, Figure 6A represents a case where there is no upper limit and the value per unit flow rate is high in terms of external value. The maximum total value e_total is at the far right, i.e., when all of the heat produced by the water electrolysis equipment 3 is supplied externally.

[0091] Applying Figure 6B to Example 4, Figure 6B illustrates a situation where the selling price of heat, a product of the water electrolysis equipment 3, to the outside world falls (for example, when demand for district heating decreases due to a mild winter, when temperatures rise and heating is no longer needed, or when the operating rate of the factory supplying heat decreases due to a shortage of raw materials).

[0092] Alternatively, increasing the heating treatment of the internal sludge treatment facility 6 and thereby increasing the amount of biogas CH4 produced increases its internal value (the sale of biogas CH4 to external parties is also included in the plant's internal value here, as it is a result of the internal use of heat). In this case, the maximum total value e_total is the leftmost value, i.e., when all the heat produced by the water electrolysis facility 3 is used internally.

[0093] Applying Figure 6C to Example 4, Figure 6C illustrates a case where, as the amount of renewable energy supplied to the water electrolysis equipment 3 increases and the amount of heat generated as a by-product increases, the upper limit for internal use (the flow rate required for heating) may exceed the upper limit for external use (the contracted sales volume). In this case, the total value e_total is maximized at the distribution point where the upper limit for external use is reached.

[0094] Although Figure 10 does not illustrate the external use of the recycled water H2O produced by the water treatment facility 2 to the outside of the plant 4, the recycled water H2O produced by the water treatment facility 2 may be used externally, such as through sale. In this case as well, the calculation of external value is performed by combining the use forms to be considered, as shown in equation (4). [Examples]

[0095] Figure 11 shows the configuration diagram of the plant operation support device 1 of the embodiment and the plant 5 to which the plant operation support device 1 is applied. The plant 5 (dashed line frame in Figure 11) to which the plant operation support device 1 of this embodiment is applied has a water treatment facility 2, a water electrolysis facility 3, and a methanation facility 7, and supplies the respective products (recycled water H2O, methane CH4, and hydrogen H2) to the outside of the plant 4.

[0096] The plant operation support device 1 includes a measurement unit 11 that monitors the operating status of the water treatment equipment 2, the water electrolysis equipment 3, and the methanation equipment 7; an internal value calculation means 12 that calculates the value of the products of the water treatment equipment 2, the water electrolysis equipment 3, and the methanation equipment 7 if they were used inside the plant based on the information from the measurement unit 11; an external value calculation means 13 that calculates the value of the products of the water treatment equipment 2, the water electrolysis equipment 3, and the methanation equipment 7 if they were used outside the plant based on information from outside the plant 4; and an operating condition planning means 14 that plans the operating conditions of the water treatment equipment 2, the water electrolysis equipment 3, and the methanation equipment 7 based on the calculation results of the internal value calculation means 12 and the external value calculation means 13, and provides these conditions to the water treatment equipment 2, the water electrolysis equipment 3, and the methanation equipment 7.

[0097] Figure 12 shows the flow of products in plant 5 to which the plant operation support device 1 of the embodiment is applied.

[0098] Water treatment facility 2 treats wastewater with microorganisms to produce recycled water H2O, which is then supplied to water electrolysis facility 3. The methanation plant 7 converts hydrogen (H2) produced in the water electrolysis plant 3 into methane (CH4) through a catalytic reaction with carbon dioxide (CO2). It converts carbon dioxide (CO2), a cause of ambient gases, into methane (CH4), which is used as fuel. Water electrolysis equipment 3 produces hydrogen (H2) and oxygen (O2) by electrolyzing water, i.e., by electrolyzing recycled water (H2O). Note that the description of oxygen (O2), a product of water electrolysis equipment 3, has been omitted.

[0099] Example 5 describes a case in which hydrogen (H2) produced in the water electrolysis equipment 3 and methane (CH4) produced in the methanation equipment 7 are utilized within the plant 5, taking into consideration the allocation for external use.

[0100] One possible external use of the hydrogen (H2) produced by the water electrolysis equipment 3 and the methane (CH4) produced by the methanation equipment 7 is sale to an external party 4 outside the plant.

[0101] One way the hydrogen (H2) produced in the water electrolysis equipment 3 can be used internally is in the methanation equipment 7. Furthermore, one way the methane (CH4) produced in the methanation equipment 7 can be used internally is for heating the methanation equipment 7 and for powering the blowers in the water treatment equipment 2, etc., within the plant 5.

[0102] As described above, the plant operation support device 1 formulates a function f_in,n(Q_in,n) in the internal value calculation means 12 (see Figure 11) to calculate the internal value of hydrogen H2 produced in the water electrolysis equipment 3 and methane CH4, a product of the methanation equipment 7, and formulates an external value calculation means 13 (see Figure 11) to calculate the external value of hydrogen H2 and methane CH4, f_out,m(Q_out,m), and plans the operating conditions, such as the operating amounts of each device, in the operating condition planning means 14 (see Figure 11) so as to maximize e_total, which represents the total value.

[0103] Next, the changes in internal value e_in, external value e_out, and total value e_total when hydrogen H2, a product of water electrolysis equipment 3, is supplied to methanation equipment 7 as an internal use form, and hydrogen H2 is sold as an external use form, will be explained with reference to Figures 6A, 6B, and 6C.

[0104] Applying Figure 6A to Example 5, Figure 6A represents a case where there is no upper limit and the value per unit flow rate is high in terms of external value. The maximum total value e_total is at the far right, i.e., when all of the hydrogen H2 produced by the water electrolysis equipment 3 is sold externally.

[0105] Applying Figure 6B to Example 5, Figure 6B illustrates a scenario where the selling price of hydrogen (H2), a product of the external water electrolysis equipment 3, falls (for example, when the supply of imported hydrogen becomes excessive and the selling price decreases).

[0106] Alternatively, increasing the processing capacity of the internal methanation facility 7 and thereby increasing the amount of methane CH4 produced can increase its internal value (the sale of methane to external sources is also included in the plant's internal value, as it is a result of the internal use of hydrogen). In this case, the maximum total value e_total is the leftmost value, i.e., when all of the methane CH4 produced by the water electrolysis facility 3 is used internally.

[0107] Applying Figure 6C to Example 4, Figure 6C illustrates a case where, as the amount of renewable energy supplied to the water electrolysis equipment 3 increases and the amount of hydrogen (H2) produced increases, the upper limit for internal use (the upper limit of the flow rate accepted by the methanation equipment 7 and the upper limit of the flow rate accepted by carbon dioxide (CO2) supply sources such as exhaust gas) exceeds the upper limit for external use (the contracted sales volume). In this example, the total value e_total is maximized at the distribution point where the upper limit for external use is reached.

[0108] The carbon dioxide (CO2) used as raw material for the methanation equipment 7 may be the carbon dioxide (CO2) produced in the biogas generated by the sludge treatment equipment 6 as shown in Example 3, or it may be purchased from outside the plant. When the carbon dioxide (CO2) in the biogas is converted to methane (CH4), the methane (CH4) content increases, making it possible to treat it as natural gas, which is generally distributed via pipelines and cylinders, thus increasing its value.

[0109] Furthermore, carbon dioxide (CO2) generated during combustion inside or outside the plant may be accepted and utilized, either for a fee or free of charge.

[0110] Although Figure 12 does not illustrate the external use of the recycled water H2O produced by the water treatment facility 2 to the outside of the plant 4, the recycled water H2O produced by the water treatment facility 2 may be used externally, such as through sale. In this case as well, the calculation of external value is performed by combining the use forms to be considered, as shown in equation (4).

[0111] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are included. The embodiments described above are described in detail for the purpose of clearly illustrating the present invention, and are not necessarily limited to those having all the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. [Explanation of Symbols]

[0112] 1. Plant operation support system 11 Measurement Unit 12. Methods for calculating internal value 13. External Value Calculation Methods 14. Operating Condition Planning Means 2. Water treatment facilities 3 Water electrolysis equipment 4. Plant exterior 5 Plants 6. Sludge Treatment Facilities 7. Methanation equipment

Claims

1. A plant operation support device that supports the operation of a plant having a water treatment facility and a water electrolysis facility that uses the recycled water produced by the water treatment facility, A measurement unit that monitors the operating status of the water treatment equipment and the water electrolysis equipment, An internal value calculation means for calculating the value of the products of the water treatment equipment or water electrolysis equipment when used within the plant, based on the monitoring information of the measurement unit, External value calculation means for calculating the value of the products of the water treatment equipment or water electrolysis equipment when used outside the plant, An operating condition planning means plans the operating conditions of the water treatment facility and the water electrolysis facility based on the calculation results of the internal value calculation means and the external value calculation means, and provides the operating conditions to the water treatment facility and the water electrolysis facility. A plant operation support device characterized by being equipped with the following features.

2. In the plant operation support device according to claim 1, The internal value calculation means calculates the value of using at least a portion of the oxygen produced in the water electrolysis equipment in the water treatment equipment. A plant operation support device characterized by the following features.

3. In the plant operation support device according to claim 1, The internal value calculation means calculates the value of using at least a portion of the recycled water produced by the water treatment facility in the water electrolysis facility. A plant operation support device characterized by the following features.

4. In the plant operation support device according to claim 1, The internal value calculation means calculates the value of using at least a portion of the oxygen produced in the water electrolysis equipment in the water treatment equipment, and the value of using at least a portion of the recycled water produced in the water treatment equipment in the water electrolysis equipment. A plant operation support device characterized by the following features.

5. In the plant operation support device according to claim 1, The aforementioned plant further includes a sludge treatment facility that generates biogas, The internal value calculation means calculates the value of using at least a portion of the oxygen produced in the water electrolysis equipment in the sludge treatment equipment, and the value of using at least a portion of the recycled water produced in the water treatment equipment in the water electrolysis equipment. A plant operation support device characterized by the following features.

6. In the plant operation support device according to claim 5, The aforementioned internal value calculation means further calculates the value of using a portion of the biogas produced in the sludge treatment facility in a plant that includes the sludge treatment facility. A plant operation support device characterized by the following features.

7. In the plant operation support device according to claim 1, The aforementioned plant further includes a sludge treatment facility that generates biogas, The internal value calculation means calculates the value of using at least a portion of the heat generated by the water electrolysis equipment in the sludge treatment equipment. A plant operation support device characterized by the following features.

8. In the plant operation support device according to claim 7, The aforementioned internal value calculation means further calculates the value of using a portion of the biogas produced in the sludge treatment facility in a plant that includes the sludge treatment facility. A plant operation support device characterized by the following features.

9. In the plant operation support device according to claim 1, The aforementioned plant further includes a methanation facility that produces methane, The internal value calculation means calculates the value of using at least a portion of the hydrogen produced in the water electrolysis equipment in the methanation equipment. A plant operation support device characterized by the following features.

10. In the plant operation support device according to claim 9, The aforementioned internal value calculation means further calculates the value of using a portion of the methane produced by the methanation equipment in a plant that includes the methanation equipment. A plant operation support device characterized by the following features.

11. In a plant operation support device according to any one of claims 1 to 10, The aforementioned operating condition planning means provides operating conditions for at least the water treatment equipment and the water electrolysis equipment that maximize the total value, which is the sum of the internal and external use values ​​of the product, including future value. A plant operation support device characterized by the following features.

12. In a plant operation support device according to any one of claims 1 to 10, The aforementioned external value calculation means calculates the value of recycled water, a product of the water treatment facility, when used outside the plant, as blue carbon related to carbon sequestration in marine ecosystems. A plant operation support device characterized by the following features.

13. A plant operation support device according to any one of claims 1 to 10, further, The system includes a display means for displaying the internal value calculated by the internal value calculation means, the external value calculated by the external value calculation means, and the total value which is the sum of the internal value and the external value. A plant operation support device characterized by the following features.

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