Methanol preparation system and preparation method thereof

Abstract

The invention provides a methanol preparation system and a methanol preparation method, and relates to the technical field of methanol preparation. The preparation system comprises: a hydrogen source configured to provide green hydrogen; a gas source configured to provide a crude syngas; the conversion device is connected with the hydrogen source and is configured to perform conversion reaction on the crude synthesis gas so as to obtain the synthesis gas with the hydrogen-carbon ratio adjusted; the synthesis device is connected with the conversion device and the hydrogen source, and is configured to prepare methanol based on the synthesis gas and the green hydrogen after the hydrogen-carbon ratio is adjusted; the desulfurization and decarbonization device is arranged between the conversion device and the synthesis device; the valves comprise a first valve, a second valve, a third valve and a fourth valve; and the processing device is respectively connected with the first valve, the second valve, the third valve and the fourth valve. According to the method, no conversion or minimum conversion of the synthesis gas is realized, the maximum hydrogen supplementing amount is increased, meanwhile, the methanol yield is increased, and the methanol production cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of methanol preparation, and in particular to a methanol preparation system and a preparation method thereof. BACKGROUND

[0002] New energy hydrogen production has many advantages such as no pollution, large output and rich raw materials, and can be applied to many chemical industries, for example, new energy hydrogen production coupled with biomass to produce green methanol.

[0003] In the production process of new energy hydrogen production coupled with biomass to produce green methanol, the hydrogen production is also fluctuated due to the influence of new energy load fluctuation, and the fluctuation has the characteristics of fast change speed, large amplitude and irregularity, which will adversely affect the purity and yield of the prepared methanol.

[0004] Therefore, the yield of methanol prepared by the existing preparation system is affected by the hydrogen production. Since the shift device needs to be ventilated to reach the minimum load threshold for normal operation, the input amount of crude synthesis gas needs to reach at least the minimum load threshold, and when the green hydrogen production is low, it will cause waste of part of the crude synthesis gas, further increasing the production cost of green methanol. SUMMARY

[0005] The embodiments of the present application provide a methanol preparation system and a preparation method thereof to solve the problem of high cost of preparing green methanol by the existing production process.

[0006] In a first aspect, the present application provides a methanol preparation system, comprising:

[0007] a hydrogen source configured to provide green hydrogen;

[0008] a gas source configured to provide crude synthesis gas;

[0009] a shift device connected with the hydrogen source and configured to perform a shift reaction on the crude synthesis gas to obtain synthesis gas with adjusted hydrogen-carbon ratio;

[0010] a synthesis device connected with the shift device and the hydrogen source and configured to prepare methanol based on the synthesis gas with adjusted hydrogen-carbon ratio and the green hydrogen;

[0011] a desulfurization and decarbonization device arranged between the shift device and the synthesis device and configured to remove impurities in the synthesis gas;

[0012] valves including a first valve arranged between the hydrogen source and the shift device, a second valve arranged between the hydrogen source and the synthesis device, a third valve arranged between the gas source and the shift device, and a fourth valve;

[0013] a processing device connected with the first valve, the second valve, the third valve and the fourth valve respectively and configured to:

[0014] obtaining a production rate of the green hydrogen;

[0015] controlling opening degrees of the first, second, third and fourth valves based on the production rate of the green hydrogen, to adjust distribution of flow rates of the green hydrogen and the crude synthesis gas in the shift device and the synthesis device, so that the synthesis device synthesizes methanol based on the adjusted flow rates.

[0016] In a possible implementation, the hydrogen source comprises a hydrogen tank, and / or an electrolytic water hydrogen production device.

[0017] In a possible implementation, a compressor is further arranged between the hydrogen source and the shift device, and / or between the hydrogen source and the synthesis device.

[0018] In a possible implementation, the compressor comprises a high-pressure hydrogen compressor, an inlet of the high-pressure hydrogen compressor being connected to the hydrogen source, and outlets of the high-pressure hydrogen compressor being respectively connected to the shift device and the synthesis device.

[0019] In a possible implementation, the compressor further comprises a medium-pressure hydrogen compressor, an inlet of the medium-pressure hydrogen compressor being connected to the hydrogen source, and outlets of the medium-pressure hydrogen compressor being respectively connected to the high-pressure hydrogen compressor and the synthesis device.

[0020] In a possible implementation, the shift device comprises:

[0021] a hydrogen preheater configured to heat the green hydrogen provided by the high-pressure hydrogen compressor.

[0022] In a second aspect, the present application provides a method for preparing methanol, the methanol being prepared by a preparation system, the preparation system comprising:

[0023] a hydrogen source configured to provide green hydrogen;

[0024] a gas source configured to provide crude synthesis gas;

[0025] a shift device connected to the hydrogen source and configured to perform a shift reaction on the crude synthesis gas to obtain synthesis gas with an adjusted hydrogen-carbon ratio;

[0026] a synthesis device connected to the shift device and the hydrogen source and configured to prepare methanol based on the synthesis gas with the adjusted hydrogen-carbon ratio and the green hydrogen;

[0027] a desulfurization and decarbonization device arranged between the shift device and the synthesis device and configured to remove impurities in the synthesis gas;

[0028] valves comprising a first valve arranged between the hydrogen source and the shift device, a second valve arranged between the hydrogen source and the synthesis device, a third valve arranged between the gas source and the shift device, and a fourth valve.

[0029] The processing device is connected with the first valve, the second valve, the third valve and the fourth valve respectively, and the preparation method of the methanol comprises:

[0030] Obtaining a production rate of the green hydrogen;

[0031] Based on the production rate of the green hydrogen, the opening degree of the first valve, the second valve, the third valve and the fourth valve is controlled to adjust the flow distribution of the green hydrogen and the crude synthesis gas in the shift device and the synthesis device, so that the synthesis device synthesizes methanol based on the adjusted flow.

[0032] In a possible implementation, based on the production rate of the green hydrogen, the opening degree of the first valve, the second valve, the third valve and the fourth valve is controlled to adjust the flow distribution of the green hydrogen and the crude synthesis gas in the shift device and the synthesis device, comprising:

[0033] In the case that the production rate of the green hydrogen is greater than or equal to the first rate, the opening degree of the first valve, the second valve, the third valve and the fourth valve is controlled to make the green hydrogen and the synthesis gas meet the first load threshold of the shift device and the synthesis demand of the synthesis device.

[0034] In a possible implementation, based on the production rate of the green hydrogen, the opening degree of the first valve, the second valve, the third valve and the fourth valve is controlled to adjust the flow distribution of the green hydrogen and the crude synthesis gas in the shift device and the synthesis device, comprising: in the case that the production rate of the green hydrogen is greater than or equal to the second rate and less than the first rate, based on the detection result of the hydrogen-carbon ratio detection element, the opening degree of the third valve and the fourth valve is controlled to dynamically adjust the amount of synthesis gas entering the synthesis device.

[0035] In a possible implementation, based on the production rate of the green hydrogen, the opening degree of the first valve, the second valve, the third valve and the fourth valve is controlled to adjust the flow distribution of the green hydrogen and the crude synthesis gas in the shift device and the synthesis device, comprising: in the case that the production rate of the green hydrogen is less than the second rate, the opening degree of the first valve, the second valve, the third valve and the fourth valve is controlled to make the green hydrogen only pass into the synthesis device, and the synthesis gas meets the first load threshold of the shift device.

[0036] The methanol preparation system and preparation method provided by the application, by setting a hydrogen source configured to provide green hydrogen, a gas source configured to provide raw synthesis gas, a shift device connected with the hydrogen source and configured to perform a shift reaction on the raw synthesis gas to obtain synthesis gas with adjusted hydrogen-carbon ratio, a synthesis device connected with the shift device and the hydrogen source and configured to prepare methanol based on the synthesis gas with adjusted hydrogen-carbon ratio and the green hydrogen, and valves including a first valve arranged between the hydrogen source and the shift device, a second valve arranged between the hydrogen source and the synthesis device, and a third valve arranged between the gas source and the shift device, a processing device connected with the first valve, the second valve and the third valve respectively and configured to: obtain the production rate of the green hydrogen; based on the production rate of the green hydrogen, control the opening degree of the first valve, the second valve and the third valve to adjust the distribution of the flow of the green hydrogen in the shift device and the synthesis device, so that the synthesis device synthesizes methanol based on the adjusted flow, compared with the defects in the prior art, the application adjusts the flow distribution according to the production amount of the green hydrogen, realizes no shift or minimum shift of the synthesis gas under the premise of ensuring the safe operation of the shift device, improves the maximum hydrogen supplement amount, and at the same time, maximizes the amount of carbon monoxide produced by biomass gasification into the methanol synthesis system, improves the methanol production amount, and reduces the methanol production cost. BRIEF DESCRIPTION OF DRAWINGS

[0037] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and serve to explain the principles of the application.

[0038] Figure 1 A preparation system structure schematic diagram of green methanol synthesized by using existing green hydrogen and raw synthesis gas;

[0039] Figure 2 A methanol preparation system structure schematic diagram provided by an embodiment of the application;

[0040] Figure 3 A hydrogen source structure schematic diagram provided by an embodiment of the application;

[0041] Figure 4 Another hydrogen source structure schematic diagram provided by an embodiment of the application;

[0042] Figure 5 Still another hydrogen source structure schematic diagram provided by an embodiment of the application;

[0043] Figure 6 A methanol preparation system structure schematic diagram provided by an embodiment of the application and containing a compressor;

[0044] Figure 7 A partial structure schematic diagram of a methanol preparation system provided by an embodiment of the application and containing a compressor;

[0045] Figure 8 Another schematic diagram of a part of a methanol production system comprising a compressor according to an embodiment of the present application is provided.

[0046] Figure 9 A schematic diagram of a whole structure of a methanol production system according to an embodiment of the present application is provided.

[0047] Figure 10 A schematic diagram of a process of producing synthesis gas according to an embodiment of the present application is provided.

[0048] Explanation of reference numerals:

[0049] 100: hydrogen source; 101: hydrogen production device by electrolysis of water; 102: hydrogen storage tank

[0050] 200: gas source

[0051] 300: shift device; 301: shift line; 302: unshifted line

[0052] 400: desulfurization and decarbonization device

[0053] 500: synthesis device; 501: hydrogen / carbon ratio detection element

[0054] 600: processing device

[0055] 701: first valve; 702: second valve; 703: third valve; 704: fourth valve

[0056] 800: compressor; 801: high-pressure hydrogen compressor; 802: medium-pressure hydrogen compressor

[0057] The above-described drawings show specific embodiments of the present application, and more detailed descriptions will be given hereinafter. These drawings and written descriptions are not intended to limit the scope of the present application concept in any way, but to explain the present application concept to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0058] Exemplary embodiments will be described in detail with reference to the drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like elements. The following detailed description is not intended to represent all embodiments in accordance with the present application. Rather, they are merely examples in accordance with some aspects of the present application as detailed in the appended claims.

[0059] In the process of new energy hydrogen coupling biomass green methanol, hydrogen comes from green hydrogen produced by new energy electrolysis of water, and carbon source comes from biomass gasification. Therefore, the availability of biomass and the production cost of green hydrogen are important factors affecting the production amount and cost of green methanol.

[0060] The existing biomass gasification operation load is stable, that is, the yield of crude synthesis gas is relatively stable, but the yield of green hydrogen fluctuates with the fluctuation of new energy load. For example, the wind power in new energy is affected by the strength of wind and fluctuates, and the solar power in new energy is affected by the intensity of light and fluctuates. This fluctuation has the characteristics of fast change speed, large amplitude and irregularity.

[0061] Figure 1 The present application provides a preparation system structure diagram for synthesizing green methanol from existing green hydrogen and crude synthesis gas. Based on the existing preparation system, gas source 200 provides crude synthesis gas, hydrogen source 100 provides green hydrogen, crude synthesis gas is input into shift device 300 to adjust the hydrogen-carbon ratio, then passes through desulfurization and decarburization device 400, and then is transported to synthesis device 500 together with the supplemented green hydrogen, so as to prepare methanol.

[0062] In order to realize stable hydrogen supply or relatively stable hydrogen supply, the existing process usually sets a large hydrogen storage volume, which increases the cost of green hydrogen and further increases the preparation cost of green synthesis gas.

[0063] In actual engineering design, in order to reduce the cost of hydrogen storage, a multi-steady-state hydrogen supply strategy is usually adopted to reduce the scale of hydrogen storage.

[0064] For example, by adjusting the shift line load through the change of hydrogen supply amount, the process gas module of the methanol synthesis is kept stable.

[0065] For example, when the yield of green hydrogen increases, the amount of green hydrogen supplied to the downstream is increased, and the shift line load of shift device 300 is reduced; when the yield of green hydrogen is small or zero, the shift line load of shift device 300 is increased.

[0066] For green hydrogen coupling biomass gasification to prepare green methanol, the maximum hydrogen supplement amount corresponds to the working condition of zero shift load, that is, the synthesis gas produced by gasification does not pass through the shift device to adjust the hydrogen-carbon ratio, but only through the supplement amount of green hydrogen to adjust the hydrogen-carbon ratio of the synthesis gas.

[0067] Since the shift device 300 needs to be normally operated under the condition that the air flow reaches the minimum load threshold, the input amount of crude synthesis gas needs to reach at least the minimum load threshold.

[0068] For example, in order to ensure that the shift device 300 does not overheat or the operating temperature is not lower than the dew point, the shift device 300 needs to be continuously operated and the minimum operating load cannot be lower than 30-40% of the normal load.

[0069] Therefore, the maximum hydrogen supplement amount is limited by the minimum load of the shift device 300, and cannot reach the theoretical maximum, resulting in a decrease in the supplement hydrogen capacity and an increase in the hydrogen storage capacity, thereby increasing the green hydrogen production cost, and part of the carbon monoxide is still involved in the shift reaction to become carbon dioxide, wasting the scarce carbon source.

[0070] Based on the above technical problems, the present application is to supplement hydrogen to the shift device with excess hydrogen during the green hydrogen peak to maintain the minimum load of the shift device with hydrogen; and during the green hydrogen valley, the green hydrogen is used for preparing methanol, so that the raw synthesis gas can be fully applied to the methanol synthesis, thereby solving the above technical problems of the prior art.

[0071] Figure 2 A schematic structural diagram of a methanol preparation system is provided for an embodiment of the present application. As shown in the figure, Figure 2 The methanol preparation system comprises:

[0072] A hydrogen source 100 configured to provide green hydrogen;

[0073] A gas source 200 configured to provide raw synthesis gas;

[0074] A shift device 300 connected with the hydrogen source 100 and configured to perform a shift reaction on the raw synthesis gas to obtain synthesis gas with an adjusted hydrogen-carbon ratio;

[0075] A synthesis device 500 connected with the shift device 300 and the hydrogen source 100 and configured to prepare methanol based on the synthesis gas with the adjusted hydrogen-carbon ratio and the green hydrogen;

[0076] A desulfurization and decarbonization device 400 arranged between the shift device 300 and the synthesis device 500 and configured to remove H2S, CO2 and various impurities such as organic sulfur from the synthesis gas;

[0077] When the corresponding green hydrogen amount is sufficient to reduce the operating load of the shift device 300 to the minimum load, the present application proposes to supplement green hydrogen to the shift device 300 to replace the amount of synthesis gas entering the shift, to realize no shift or minimum shift of the synthesis gas under the premise of ensuring the safe operation of the shift device 300, to increase the maximum hydrogen supplement amount, and to maximize the amount of carbon monoxide produced by biomass gasification into the methanol synthesis preparation system, to increase the methanol production, and to reduce the methanol production cost.

[0078] Figure 3 A schematic structural diagram of a hydrogen source is provided for an embodiment of the present application; Figure 4 Another schematic structural diagram of a hydrogen source is provided for an embodiment of the present application; Figure 5 Still another schematic structural diagram of a hydrogen source is provided for an embodiment of the present application.

[0079] Reference Figure 3As shown, the hydrogen source 100 includes a water electrolysis hydrogen production device 101. It should be understood that the hydrogen source 100 can also be other hydrogen production devices other than the water electrolysis hydrogen production device 101.

[0080] Reference is made to Fig. 1, which shows a schematic diagram of a methanol production system according to an embodiment of the present application. Figure 4 As shown, the hydrogen source 100 includes a hydrogen storage tank 102.

[0081] Reference is made to Fig. 1, which shows a schematic diagram of a methanol production system according to an embodiment of the present application. Figure 5 As shown, the hydrogen source 100 includes a water electrolysis hydrogen production device 101 and a hydrogen storage tank 102. The water electrolysis hydrogen production device 101 is connected to the hydrogen storage tank 102, and the hydrogen produced by the water electrolysis hydrogen production device 101 is stored in the hydrogen storage tank 102.

[0082] Figure 6 Reference is made to Fig. 1, which shows a schematic diagram of a methanol production system according to an embodiment of the present application. Figure 6 As shown, the methanol production system includes:

[0083] The hydrogen source 100 is configured to provide green hydrogen;

[0084] The gas source 200 is configured to provide raw synthesis gas;

[0085] The shift device 300 is connected to the hydrogen source 100 and is configured to perform a shift reaction on the raw synthesis gas to obtain synthesis gas with an adjusted hydrogen-carbon ratio;

[0086] The desulfurization and decarbonization device 400 is arranged between the shift device 300 and the synthesis device 500 and is configured to remove H2S, CO2 and various organic sulfur impurities from the synthesis gas;

[0087] The synthesis device 500 is connected to the shift device 300 and the hydrogen source 100 and is configured to produce methanol based on the synthesis gas with an adjusted hydrogen-carbon ratio and green hydrogen;

[0088] The compressor 800 is arranged between the hydrogen source 100 and the shift device 300;

[0089] Alternatively, the compressor 800 is arranged between the hydrogen source 100 and the synthesis device 500;

[0090] Alternatively, the compressor 800 is arranged between the hydrogen source 100 and the shift device 300 and between the hydrogen source 100 and the synthesis device 500.

[0091] According to the present application, the compressor 800 can increase the pressure of the green hydrogen to adapt to the pressure requirements of the shift device 300 and / or the synthesis device 500, ensuring that the shift reaction and the synthesis reaction of the present application can proceed smoothly.

[0092] Figure 7 Reference is made to Fig. 1, which shows a schematic diagram of a methanol production system according to an embodiment of the present application. Figure 7As shown, the compressor includes a high-pressure hydrogen compressor 801.

[0093] The inlet of the high-pressure hydrogen compressor 801 is connected to the hydrogen source 100, and the outlet is connected to the shift device 300 and the synthesis device 500, respectively.

[0094] Figure 8 Another partial structure schematic diagram of a methanol preparation system provided by the embodiment of the present application is shown in FIG. 4. As shown in FIG. 4, the methanol preparation system includes a hydrogen source 100, a gas source 200, a shift device 300, a synthesis device 500, a desulfurization and decarburization device 400, a compressor, and a processing device 600. Figure 8 As shown, the compressor further includes a medium-pressure hydrogen compressor 802.

[0095] The inlet of the medium-pressure hydrogen compressor 802 is connected to the hydrogen source 100, and the outlet is connected to the high-pressure hydrogen compressor 801 and the synthesis device 500, respectively. The high-pressure hydrogen compressor 801 and the medium-pressure hydrogen compressor 802 can be connected in parallel or in series.

[0096] Figure 9 A schematic diagram of the overall structure of a methanol preparation system provided by the embodiment of the present application is shown in FIG. 5. As shown in FIG. 5, the methanol preparation system includes a hydrogen source 100, a gas source 200, a shift device 300, a synthesis device 500, a desulfurization and decarburization device 400, a compressor, and a processing device 600. Figure 9 As shown, the methanol preparation system includes:

[0097] The hydrogen source 100 is configured to provide green hydrogen.

[0098] The gas source 200 is configured to provide raw synthesis gas.

[0099] The shift device 300 is connected to the hydrogen source 100 and is configured to perform a shift reaction on the raw synthesis gas to obtain synthesis gas with an adjusted hydrogen-carbon ratio.

[0100] The synthesis device 500 is connected to the shift device 300 and the hydrogen source 100 and is configured to prepare methanol based on the synthesis gas with the adjusted hydrogen-carbon ratio and the green hydrogen.

[0101] The desulfurization and decarburization device 400 is arranged between the shift device 300 and the synthesis device 500 and is configured to remove H2S, CO2, and various organic sulfur impurities from the synthesis gas.

[0102] The valve includes a first valve 701 arranged between the hydrogen source 100 and the shift device 300, a second valve 702 arranged between the hydrogen source 100 and the synthesis device 500, and a third valve 703 arranged between the gas source 200 and the shift device 300.

[0103] Optionally, the valve further includes a fourth valve 704 arranged between the gas source 200 and the desulfurization and decarburization device 400.

[0104] The processing device 600 is connected to the first valve 701, the second valve 702, the third valve 703, and the fourth valve 704, respectively.

[0105] In some embodiments, the synthesis device 500 is further provided with a hydrogen-carbon ratio detection element 501 for detecting the hydrogen-carbon ratio of the gas entering the synthesis device 500, and the processing device 600 is connected to the hydrogen-carbon ratio detection element 501, and the processing device 600 can satisfy the synthesis demand of methanol based on the H / C signal recognized by the hydrogen-carbon ratio detection element 501.

[0106] The processing device 600 is configured to control the opening degree of the first valve 701, the second valve 702, the third valve 703, and the fourth valve 704 to adjust the distribution of the flow of the green hydrogen in the shift device 300 and the synthesis device 500, so that the synthesis device 500 synthesizes methanol based on the adjusted flow.

[0107] The high-pressure hydrogen gas compressor 801 is configured to control the green hydrogen from the hydrogen source 100 to be delivered to the shift device 300 and the synthesis device 500, respectively.

[0108] For example, the inlet of the high-pressure hydrogen gas compressor 801 is connected to the hydrogen source 100, and the outlet is connected to the shift device 300 and the synthesis device 500, respectively.

[0109] The medium-pressure hydrogen gas compressor 802 is configured to control the green hydrogen from the hydrogen source 100 to be delivered to the high-pressure hydrogen gas compressor 801 and the synthesis device 500, respectively.

[0110] For example, the inlet of the medium-pressure hydrogen gas compressor 802 is connected to the hydrogen source 100, and the outlet is connected to the high-pressure hydrogen gas compressor 801 and the synthesis device 500, respectively.

[0111] For example, the high-pressure hydrogen gas compressor 801 can provide hydrogen required for synthesis to the shift device 300 in the case of high load hydrogen production of the hydrogen source, and provide hydrogen to the synthesis device 500 of methanol or self-reflux in other conditions.

[0112] The medium-pressure hydrogen gas compressor 802 provides hydrogen to the downstream synthesis device 500, and also provides hydrogen to the high-pressure hydrogen gas compressor 801. Therefore, the inlet hydrogen of the high-pressure hydrogen gas compressor 801 can be supplied by the medium-pressure hydrogen gas compressor 802 or directly from the hydrogen storage tank 102.

[0113] Optionally, since the shift device 300 is used to heat and shift the raw synthesis gas from the gas source 200 to adapt to the raw material ratio of methanol synthesis, but after the green hydrogen is introduced into the shift device 300, the temperature of the shift device 300 will be affected due to the addition of green hydrogen, thereby affecting the shift depth.

[0114] Therefore, before the green hydrogen is introduced into the shift device 300, the green hydrogen is first preheated to reduce the influence on the raw synthesis gas.

[0115] For example, when hydrogen is in peak, the conversion depth of the conversion device 300 is reduced, and reducing the conversion depth requires reducing the amount of raw material gas into the conversion device 300, and if the amount of raw material gas is reduced too much, the lower limit of the operation of the conversion device 300 can be easily exceeded. When the lower limit of the operation of the conversion device 300 is exceeded, if not handled properly, not only can it cause destructive accidents such as catalyst temperature runaway, but also can cause incomplete reaction, resulting in waste of raw materials.

[0116] Therefore, regardless of whether the green hydrogen is in peak or trough at any time, the load of the conversion device 300 needs to be maintained not lower than the allowable lower limit. In the peak period, the excess hydrogen is supplemented into the conversion line 301, and the syngas flow of the gas source 200 into the conversion line 301 is reduced, which can avoid over-temperature of the conversion device 300 while reducing the conversion depth.

[0117] In some embodiments, a hydrogen preheater is arranged in the conversion device 300 and configured to heat the green hydrogen provided by the high-pressure hydrogen compressor.

[0118] In some embodiments, the processing device 600 is configured to control the operation of the valves by a software control program, for example, control the opening degree of the first valve 701, the second valve 702 and the third valve 703, and the fourth valve 704.

[0119] The processing device 600 can include one or more circuits or chips with control functions.

[0120] For example, the software control program can be stored on a storage component, and the preparation system can be provided with a control platform, and the control platform is provided with the processing device 600 and the storage component.

[0121] Optionally, the storage component can be integrated with the processing device 600, or can be two independent components from the processing device 600.

[0122] The storage component is configured to store data, for example, various software control programs, some modes, strategies and / or parameters of the control platform, etc.

[0123] Specifically, the above program can include program code, and the program code includes computer operation instructions.

[0124] The execution subject of the embodiments of the present application can be a control platform in a preparation system, or a server corresponding to the control platform. The server is located in the cloud and is connected to the control platform through a network, and issues control instructions to the control platform, or forwards control instructions sent by a user through a terminal device to the control platform, etc.

[0125] The following specific embodiments take the processing device in the control platform as an example to perform the subject, and details of the technical solutions of the present application and how the technical solutions of the present application solve the above technical problems are described. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described again in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0126] Figure 10 The preparation method of methanol provided in the embodiments of the present application is shown in the flowchart. As shown in the figure, the method comprises: Figure 10

[0127] S101, obtaining the production rate of green hydrogen.

[0128] Since green hydrogen is prepared by new energy, the new energy is not stable enough. For example, the characteristics of upstream wind power or photovoltaic determine that, for photovoltaic, the light intensity changes during the day, which causes the green hydrogen to change.

[0129] For example, the production rate of green hydrogen can be calculated based on the fluctuation of new energy, or can be calculated based on the fluctuation of the gas production of the preparation device.

[0130] For example, in the case of a water electrolysis hydrogen production device as the hydrogen source, the amount of green hydrogen produced can be calculated based on the fluctuation of the obtained new energy power, and a flow sensor can also be arranged at the gas pipeline outlet of the water electrolysis hydrogen production device to directly test the production rate of green hydrogen.

[0131] In view of the fluctuation of green hydrogen, for example, the occurrence of peak period and trough period. In order to ensure that the composition of the synthesis gas supplied to the downstream device, for example, the synthesis device for synthesizing methanol, is fixed, for example, the ratio of hydrogen and carbon monoxide is fixed at 2:1, different treatments need to be carried out for the peak period and the trough period of green hydrogen.

[0132] When the production of green hydrogen is in the peak period, the conversion depth needs to be reduced.

[0133] On the contrary, when the synthesis amount of green hydrogen is in the trough period, even no hydrogen gas is produced, that is, the gas flow of the hydrogen source is 0, then the conversion reaction depth needs to be increased, so that more carbon monoxide in the crude synthesis gas produced by biomass gasification can be converted into hydrogen, thereby ensuring that the ratio of hydrogen and carbon monoxide in the crude synthesis gas at the inlet of the methanol synthesis is 2:1.

[0134] S102, in the case where the production rate of green hydrogen is greater than or equal to the first rate, controlling the opening degrees of the first valve, the second valve, the third valve and the fourth valve, so that the green hydrogen and the synthesis gas meet the first load threshold of the conversion device and the synthesis demand of the synthesis device.

[0135] ​The first load threshold is the minimum load of the shift device.

[0136] For example, if the minimum load of the shift device is 40%, and the flow rate of the crude synthesis gas is 20%, the first flow rate can be set to be between 20%-40%, and the remaining flow rate is passed into the synthesis device.

[0137] Continuing to refer to Figure 9 As shown, in the working condition of high load hydrogen production of the hydrogen source, since the hydrogen production is sufficient, the adjustment of the hydrogen-carbon ratio of the synthesis gas entering the methanol synthesis is mainly realized by directly supplementing hydrogen, but in order to meet the minimum load requirement of the shift furnace of the shift line 301, the excess hydrogen is sent into the shift line 301 of the shift device 300 to replace part of the synthesis gas, thereby reducing the amount of synthesis gas entering the shift line 301 and increasing the amount of synthesis gas entering the unshift line 302 of the shift device 300. Therefore, under this working condition, the opening of the first valve 701 is increased to full opening, the opening of the second valve 702 is increased under the condition of ensuring the maintenance of the minimum load of the shift furnace, the opening of the third valve 703 is reduced to the minimum or full closing, and the opening of the fourth valve 704 is increased to full opening. Under this working condition, the source of hydrogen is all the hydrogen supplied by the high-pressure hydrogen compressor 801.

[0138] S103, in the case that the production rate of green hydrogen is greater than or equal to the second rate and less than the first rate, based on the detection result of the hydrogen-carbon ratio detection element, the opening of the third valve and the fourth valve is controlled to dynamically adjust the amount of synthesis gas entering the synthesis device.

[0139] The first rate is greater than the second rate, the hydrogen-carbon ratio detection element can detect the hydrogen-carbon ratio entering the synthesis device in real time, and the raw material synthesis ratio of the fuel such as methanol is determined, so the hydrogen-carbon ratio can be adjusted specifically for the fuel to be synthesized, and the synthesis yield is improved.

[0140] Continuing to refer to Figure 9 As shown, when the hydrogen source 100 is between high load hydrogen production and low load hydrogen production, as the hydrogen production dynamically changes (increases or decreases), the amount of shift gas entering the shift device 300 is adjusted by controlling the opening of the third valve 703 and the fourth valve 704 to control the reaction depth of the shift device 300, thereby dynamically adjusting the hydrogen-carbon ratio of the synthesis gas entering the methanol synthesis.

[0141] S104, in the case that the production rate of green hydrogen is less than the second rate, the opening of the first valve, the second valve, the third valve and the fourth valve is controlled to make the green hydrogen only pass into the synthesis device, and the synthesis gas meets the first load threshold of the shift device.

[0142] For example, if the minimum load of the shift device is 40%, the flow rate of the crude synthesis gas can be controlled to be 40%, and the green hydrogen is all passed into the synthesis device.

[0143] With reference to the above description of the first embodiment, the second embodiment is described below. Figure 9 As shown in the figure, in the working condition of low load hydrogen production of the hydrogen source 100, due to insufficient hydrogen production, the adjustment of the hydrogen-carbon ratio of the synthesis gas entering the methanol synthesis is mainly realized by the shift reaction, so it is necessary to increase the amount of synthesis gas entering the shift line 301 and reduce the amount of synthesis gas entering the unshift line 302, so as to convert more carbon monoxide in the synthesis gas into hydrogen. Therefore, in this working condition, the opening of the first valve 701 is reduced to full closing, the opening of the second valve 702 is increased so that all hydrogen enters the methanol synthesis, the opening of the third valve 703 is increased to full opening, and the opening of the fourth valve 704 is reduced.

[0144] The method provided in the embodiment can determine whether the green hydrogen reserves are rich or the green hydrogen supply is timely by obtaining the production rate of green hydrogen, so as to use excess hydrogen to supplement the shift device, and then use hydrogen to maintain the minimum load of the shift device, and use all green hydrogen to prepare methanol when the green hydrogen is low, thereby improving the utilization rate of the crude synthesis gas.

[0145] It should be understood that the embodiments of the present application are not only limited to green hydrogen coupled with biomass gasification to prepare green methanol, but also include green hydrogen coupled with coal gasification to prepare methanol and other chemical products with specific requirements for synthesis gas composition, and all gasification processes that can be prepared by using hydrogen and carbon monoxide as the main effective gas.

[0146] The present application also provides a computer program product comprising a computer program which, when executed by a processing device, implements the method for preparing synthesis gas.

[0147] The computer program product provided in the embodiment can execute the method for preparing synthesis gas of the above-mentioned embodiments, and has similar implementation principles and technical effects, which will not be described here again in the embodiment.

[0148] The present application also provides a computer readable storage medium having computer execution instructions stored therein, when the processing device executes the computer execution instructions, the method for preparing synthesis gas is realized.

[0149] The computer readable storage medium provided in the embodiment can execute the method for preparing synthesis gas of the above-mentioned embodiments, and has similar implementation principles and technical effects, which will not be described here again in the embodiment.

[0150] The computer readable storage medium described above can be implemented by any type of volatile or nonvolatile storage devices or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general or special purpose computer.

[0151] An exemplary readable storage medium is coupled to a processing device so that the processing device can read information from the readable storage medium and the readable storage medium can write information to the processing device. Of course, the readable storage medium can also be a part of the processing device. The processing device and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processing device and the readable storage medium can also exist as discrete components in an electronic device or host device.

[0152] Those of ordinary skill in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction-related hardware. The aforementioned program can be stored in a computer readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes ROM, RAM, magnetic disk or optical disk and various storage media that can store program codes.

[0153] It should be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant laws, regulations and standards, and provide corresponding operation portal for user to choose authorization or refusal.

[0154] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A system for the production of methanol, characterized in that The method comprises the following steps: a hydrogen source configured to provide green hydrogen; a gas source configured to provide raw synthesis gas; a shift device connected with the hydrogen source and configured to perform a shift reaction on the raw synthesis gas to obtain synthesis gas with an adjusted hydrogen-carbon ratio; a synthesis device connected with the shift device and the hydrogen source and configured to prepare methanol based on the synthesis gas with the adjusted hydrogen-carbon ratio and the green hydrogen; a desulfurization and decarburization device arranged between the shift device and the synthesis device and configured to remove impurities in the synthesis gas; valves including a first valve arranged between the hydrogen source and the shift device, a second valve arranged between the hydrogen source and the synthesis device, a third valve and a fourth valve arranged between the gas source and the shift device; a processing device connected with the first valve, the second valve, the third valve, and the fourth valve respectively and configured to: obtain a production rate of the green hydrogen; based on the production rate of the green hydrogen, control the opening degree of the first valve, the second valve, the third valve, and the fourth valve to adjust the flow distribution of the green hydrogen and the raw synthesis gas in the shift device and the synthesis device, so that the synthesis device synthesizes methanol based on the adjusted flow.

2. The preparation system according to claim 1, characterized in that, The hydrogen source comprises a hydrogen storage tank and / or an electrolytic water hydrogen production device.

3. The preparation system according to claim 2, characterized in that A compressor is arranged between the hydrogen source and the shift device and / or between the hydrogen source and the synthesis device.

4. The preparation system according to claim 3, characterized in that The compressor comprises a high-pressure hydrogen compressor, the inlet of which is connected with the hydrogen source, and the outlet of which is connected with the shift device and the synthesis device respectively.

5. The production system according to claim 4, characterized in that The compressor further comprises a medium-pressure hydrogen compressor, the inlet of which is connected with the hydrogen source, and the outlet of which is connected with the high-pressure hydrogen compressor and the synthesis device respectively.

6. The production system according to claim 5, characterized in that The shift device comprises: a hydrogen preheater configured to heat the green hydrogen provided by the high-pressure hydrogen compressor.

7. A process for the preparation of methanol, characterized in that The methanol is prepared by a preparation system, which comprises: a hydrogen source configured to provide green hydrogen; a gas source configured to provide raw synthesis gas; a shift device connected with the hydrogen source and configured to perform a shift reaction on the raw synthesis gas to obtain synthesis gas with an adjusted hydrogen-carbon ratio; a synthesis device connected with the shift device and the hydrogen source and configured to prepare methanol based on the synthesis gas with the adjusted hydrogen-carbon ratio and the green hydrogen; a desulfurization and decarburization device arranged between the shift device and the synthesis device and configured to remove impurities in the synthesis gas; valves including a first valve arranged between the hydrogen source and the shift device, a second valve arranged between the hydrogen source and the synthesis device, a third valve and a fourth valve arranged between the gas source and the shift device; a processing device connected with the first valve, the second valve, the third valve, and the fourth valve respectively, and the preparation method of the methanol comprises: obtaining a production rate of the green hydrogen; based on the production rate of the green hydrogen, controlling the opening degree of the first valve, the second valve, the third valve, and the fourth valve to adjust the flow distribution of the green hydrogen and the raw synthesis gas in the shift device and the synthesis device, so that the synthesis device synthesizes methanol based on the adjusted flow.

8. The method of claim 7, wherein, The opening degree of the first valve, the second valve, the third valve and the fourth valve is controlled based on the production rate of the green hydrogen, so as to adjust the flow distribution of the green hydrogen and the crude synthesis gas in the shift device and the synthesis device, comprising: In the case that the production rate of the green hydrogen is greater than or equal to the first rate, the opening degree of the first valve, the second valve, the third valve and the fourth valve is controlled, so that the green hydrogen and the synthesis gas meet the first load threshold of the shift device and the synthesis requirement of the synthesis device.

9. The method of claim 7, wherein, The opening degree of the first valve, the second valve, the third valve and the fourth valve is controlled based on the production rate of the green hydrogen, so as to adjust the flow distribution of the green hydrogen and the crude synthesis gas in the shift device and the synthesis device, comprising: in the case that the production rate of the green hydrogen is greater than or equal to the second rate and less than the first rate, the opening degree of the third valve and the fourth valve is controlled based on the detection result of the hydrogen-carbon ratio detection element, so as to dynamically adjust the amount of the synthesis gas entering the synthesis device.

10. The method of claim 7, wherein, The opening degree of the first valve, the second valve, the third valve and the fourth valve is controlled based on the production rate of the green hydrogen, so as to adjust the flow distribution of the green hydrogen and the crude synthesis gas in the shift device and the synthesis device, comprising: in the case that the production rate of the green hydrogen is less than the second rate, the opening degree of the first valve, the second valve, the third valve and the fourth valve is controlled, so that the green hydrogen only enters the synthesis device, and the synthesis gas meets the first load threshold of the shift device.

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