Hydrogen-cooled co-production of cement kiln waste heat utilization system

Abstract

The application relates to a hydrogen-cooled combined production cement kiln waste heat utilization system, which comprises a cement kiln production module, a hydrogen production module and a refrigeration module. The cement kiln production module comprises a raw material preheater, a rotary kiln and a clinker cooler, the raw material preheater is used for preheating raw material entering the same by waste gas, the rotary kiln is used for calcining the preheated cement raw material to form cement clinker, and the clinker cooler is used for cooling the cement clinker; the hydrogen production module comprises a methanol hydrogen production loop, the raw material preheater is connected with a flue gas side inlet of a reactor of the methanol hydrogen production loop, the clinker cooler is connected with a hot side inlet of a gasifier of the methanol hydrogen production loop, and the flue gas side outlet of the reactor and the hot side outlet of the gasifier are both connected with the refrigeration module to provide a heat source for refrigeration of the refrigeration module. The cement kiln waste heat is combined with the hydrogen production module and the refrigeration module, the cement kiln waste heat can be more efficiently utilized, the step-by-step utilization of energy is realized, and the hydrogen production cost and the refrigeration cost are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste heat utilization, in particular to a hydrogen-cooled combined cement kiln waste heat utilization system. BACKGROUND

[0002] The cement industry is a high energy consumption industry, and its energy cost accounts for 70% of the production cost of the enterprise. With the development of cement calcination technology and the improvement of production efficiency, the heat consumption rate of cement clinker has been greatly reduced, but the heat consumption rate of cement clinker of 1300t / d, 2500t / d and 5000t / d new dry process cement production line is still as high as 3475kJ / kg, 3140kJ / kg and 2970kJ / kg respectively. Among them, the waste gas below 400℃ discharged from the kiln head clinker cooler and the kiln tail cyclone preheater in the cement production process accounts for more than 35% of the total heat consumption of the cement clinker firing system. If this part of low-temperature waste heat is fully and efficiently utilized, it will effectively reduce the cost of cement production, improve the energy utilization efficiency of the cement industry, and bring huge economic benefits.

[0003] Hydrogen is an ideal high-energy, zero-pollution energy carrier. Compared with the combustion of other fossil fuels, which produces greenhouse gases and harmful gases, the combustion product of hydrogen is only water, so hydrogen is also considered to be the most potential alternative energy in this century. Compared with other hydrogen production methods, methanol reforming to produce hydrogen has the advantages of low reaction temperature, high hydrogen content in product, small investment, low energy consumption, small occupied area, and mild process conditions, and China is the largest methanol producer in the world, accounting for 60% of global methanol production capacity. Using methanol to reform hydrogen has the advantage of cheap and readily available raw materials.

[0004] Absorption refrigeration is the most widely used heat-driven refrigeration technology. Absorption refrigeration technology has the advantages of low power consumption and good economic performance.

[0005] However, in the related art, there is no structure that combines a cement kiln waste heat utilization system, a methanol reforming hydrogen production reaction, and an absorption refrigeration technology. SUMMARY

[0006] The present application aims to at least partially solve one of the technical problems in the related art.

[0007] To this end, an embodiment of the present application proposes a hydrogen-cooled combined cement kiln waste heat utilization system, which combines cement kiln waste heat with a hydrogen production module and a refrigeration module, can more efficiently utilize cement kiln waste heat, can realize cascade utilization of energy, improve the energy utilization efficiency of the cement industry, and reduce the production cost of hydrogen and the refrigeration cost.

[0008] The hydrogen cold co-production cement kiln waste heat utilization system of the embodiment of the present application comprises: a cement kiln production module, the cement kiln production module comprises a raw material preheater, a rotary kiln and a clinker cooler connected in sequence, the raw material preheater is used for preheating cement raw materials, the rotary kiln is used for calcining the preheated cement raw materials to form cement clinker, and the clinker cooler is used for cooling the cement clinker; a hydrogen production module, the hydrogen production module comprises a methanol hydrogen production loop, the methanol hydrogen production loop has a reactor and a gasifier, the raw material preheater is connected with the flue gas side of the reactor, and the clinker cooler is connected with the hot side of the gasifier.

[0009] The hydrogen cold co-production cement kiln waste heat utilization system of the embodiment of the present application can utilize the waste gas generated by the cement kiln production module to provide energy for the hydrogen production module and the refrigeration module, so that the waste heat energy of the cement kiln production module is reasonably utilized, the energy utilization efficiency of the cement industry is improved, the cost of boilers and other equipment required in the hydrogen production process and the fuel required for operation are reduced, the hydrogen production cost is reduced, and the refrigeration cost is also reduced by using the heat contained in the waste gas.

[0010] In some embodiments, the methanol hydrogen production loop further comprises: a feeding device, a preheater, a cooler, a gas-liquid separator, a pressure swing adsorber and a hydrogen storage tank, the feeding device is used for supplying methanol raw material liquid, the feeding device is connected with the cold side inlet of the preheater, the cold side outlet of the preheater is connected with the cold side inlet of the gasifier, the cold side outlet of the gasifier is connected with the shell side inlet of the reactor, the shell side outlet of the reactor is connected with the hot side inlet of the preheater, the hot side outlet of the preheater is connected with the hot side inlet of the cooler, the hot side outlet of the cooler is connected with the inlet of the gas-liquid separator, the gas side outlet of the gas-liquid separator is connected with the inlet of the pressure swing adsorber, and the outlet of the pressure swing adsorber is connected with the inlet of the hydrogen storage tank.

[0011] In some embodiments, the feeding device comprises a desalted water storage tank, a methanol storage tank and a methanol raw material liquid pump, the desalted water storage tank is used for storing desalted water, the methanol storage tank is used for storing methanol, water in the desalted water storage tank and methanol in the methanol storage tank are mixed in a certain proportion and then enter the methanol raw material liquid pump, and the outlet of the methanol raw material liquid pump is connected with the cold side inlet of the preheater.

[0012] In some embodiments, the liquid side outlet of the gas-liquid separator is connected with the inlet of the methanol raw material liquid pump, and liquid substances separated from the liquid side outlet of the gas-liquid separator can enter the inlet of the methanol raw material liquid pump.

[0013] In some embodiments, the shell side of the reactor is filled with catalysts required for methanol reforming hydrogen production reaction.

[0014] In some embodiments, the raw material preheater is a cyclone preheater.

[0015] In some embodiments, the refrigeration module is a lithium bromide absorption chiller. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a cement kiln waste heat utilization system with hydrogen cooling cogeneration according to an embodiment of the present invention.

[0017] Figure label:

[0018] 1. Clinker cooler; 2. Rotary kiln; 3. Cyclone preheater; 4. Demineralized water storage tank; 5. Methanol storage tank; 6. Methanol feedstock pump; 7. Preheater; 8. Gasifier; 9. Reactor; 10. Cooler; 11. Gas-liquid separator; 12. Pressure swing adsorption unit; 13. Hydrogen storage tank; 14. Lithium bromide absorption chiller. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0020] The following is a reference appendix. Figure 1 A waste heat utilization system for a cement kiln with hydrogen cooling cogeneration is described according to an embodiment of the present invention.

[0021] like Figure 1 As shown, a cement kiln waste heat utilization system for hydrogen-cooled cogeneration according to an embodiment of the present invention includes: a cement kiln production module, a hydrogen production module, and a refrigeration module. The cement kiln production module includes a raw meal preheater, a rotary kiln 2, and a clinker cooler 1 connected in sequence. The raw meal preheater is used to preheat the cement raw meal, the rotary kiln 2 is used to calcine the preheated cement raw meal to form cement clinker, and the clinker cooler 1 is used to cool the cement clinker. The hydrogen production module includes a methanol-to-hydrogen circuit, which has a reactor 9 and a gasifier 8. The raw meal preheater is connected to the flue gas inlet of the reactor 9, the clinker cooler 1 is connected to the hot-side inlet of the gasifier 8, and both the flue gas outlet of the reactor 9 and the hot-side outlet of the gasifier 8 are connected to the refrigeration module.

[0022] An embodiment of the present invention provides a cement kiln waste heat utilization system for hydrogen-cooled cogeneration. This system can utilize the waste gas generated by the cement kiln production module to provide energy for the hydrogen production module and the refrigeration module, thereby making reasonable use of the waste heat energy of the cement kiln production module, improving the energy utilization efficiency of the cement industry, reducing the boiler cost and fuel cost required for the hydrogen production process, lowering the cost of hydrogen production, and also reducing the refrigeration cost by using the heat contained in the waste gas for refrigeration.

[0023] For example, the raw material preheater is a cyclone preheater 3, which is arranged at the top of the cement kiln, and the raw cement is preheated by the flue gas after combustion in the cyclone preheater 3. The flue gas after preheating the raw cement still has a high temperature, and the preheated cement raw material enters the rotary kiln 2 to be calcined into cement clinker, and then the cement clinker is sent into the clinker cooler 1 to be cooled by a large amount of air, and the cooling air is also heated by the cement clinker to become flue gas with a high temperature.

[0024] The flue gas after preheating the cement raw material enters the reactor 9 from the flue gas side of the reactor 9, and in the reactor 9, the flue gas uses the heat energy it carries to maintain the methanol reforming reaction to produce hydrogen. The flue gas in the clinker cooler 1 enters the gasifier 8 from the hot side inlet of the gasifier 8, and in the gasifier 8, the flue gas transfers the heat energy it carries to the methanol raw material liquid to heat and gasify the methanol raw material liquid into gaseous reaction raw material. After the flue gas completes heat exchange in the reactor 9 and the gasifier 8, it is combined and enters the refrigeration module, and the refrigeration module generates cold energy using the flue gas as a heat source.

[0025] For example, the refrigeration module is a lithium bromide absorption refrigerator 14. A hydrogen-cooled cogeneration cement kiln waste heat utilization system according to an embodiment of the present application can realize step-by-step utilization of energy and improve energy utilization rate by using the flue gas to first produce hydrogen by methanol reforming and then to drive the lithium bromide absorption refrigerator 14 according to the required flue gas temperature.

[0026] Optionally, the methanol hydrogen production loop further includes a feeding device, a preheater 7, a cooler 10, a gas-liquid separator 11, a pressure swing adsorber 12, and a hydrogen storage tank 13. The feeding device includes a desalted water storage tank 4, a methanol storage tank 5, and a methanol raw material liquid pump 6. The desalted water storage tank 4 is used to store desalted water, the methanol storage tank 5 is used to store methanol, and the desalted water in the desalted water storage tank 4 and the methanol in the methanol storage tank 5 are mixed in a certain proportion and then enter the methanol raw material liquid pump 6.

[0027] The outlet of the methanol raw material liquid pump 6 is connected to the cold side inlet of the preheater 7, the cold side outlet of the preheater 7 is connected to the cold side inlet of the gasifier 8, the cold side outlet of the gasifier 8 is connected to the shell side inlet of the reactor 9, the shell side outlet of the reactor 9 is connected to the hot side inlet of the preheater 7, the hot side outlet of the preheater 7 is connected to the hot side inlet of the cooler 10, the hot side outlet of the cooler 10 is connected to the inlet of the gas-liquid separator 11, the gas side outlet of the gas-liquid separator 11 is connected to the inlet of the pressure swing adsorber 12, and the outlet of the pressure swing adsorber 12 is connected to the inlet of the hydrogen storage tank 13. The shell side of the reactor 9 is filled with catalysts required for the methanol reforming reaction to produce hydrogen, and the methanol reforming reaction to produce hydrogen is carried out in the shell side of the reactor 9.

[0028] It can be understood that the desalted water stored in the desalted water storage tank 4 is mixed with the methanol stored in the methanol storage tank 5 in a certain proportion to become a methanol raw material liquid, the methanol raw material liquid is pressurized by the methanol raw material liquid pump 6 and enters the preheater 7 from the cold side inlet of the preheater 7, in the preheater 7, the methanol raw material liquid is preheated by the reaction product of the methanol reforming hydrogen production, the preheated methanol raw material liquid enters the gasifier 8 from the cold side inlet of the gasifier 8, in the gasifier 8, the methanol raw material liquid is heated by the waste gas generated by the clinker cooler 1 and is further gasified into a gaseous reaction raw material, and then the gaseous reaction raw material enters the reactor 9 from the shell side inlet of the reactor 9. In the reactor 9, the gaseous reaction raw material is subjected to the methanol reforming hydrogen production reaction under the action of the catalyst and the heating of the waste gas outlet of the cyclone preheater 3, and is changed into a reaction product, and then the methanol reforming hydrogen production reaction product flows out from the shell side outlet of the reactor 9, enters the preheater 7 from the hot side inlet of the preheater 7, and uses its own heat to preheat the methanol raw material liquid, and then the reaction product flows out from the hot side outlet of the preheater 7 and enters the cooler 10 for cooling, and the cooled reaction product enters the gas-liquid separator 11 to realize gas-liquid separation, wherein the gaseous material in the reaction product enters the pressure swing adsorber 12 to be purified into pure hydrogen gas and is stored in the hydrogen storage tank 13.

[0029] Alternatively, the liquid side outlet of the gas-liquid separator 11 is connected to the inlet of the methanol raw material liquid pump 6, and the liquid material separated by the liquid side outlet of the gas-liquid separator 11 can be introduced into the inlet of the methanol raw material liquid pump 6. It can be understood that the cooled reaction product enters the gas-liquid separator 11 to realize gas-liquid separation, and the liquid material therein is unreacted methanol raw material liquid, which is mixed with the methanol raw material liquid at the inlet of the methanol raw material liquid pump 6 to participate in the methanol reforming hydrogen production reaction again, thereby improving the utilization rate of the raw material and reducing the loss of the raw material.

[0030] In summary, the hydrogen cold combined production cement kiln waste heat utilization system of the embodiment of the present application has at least the following technical effects.

[0031] (1) The hydrogen cold combined production cement kiln waste heat utilization system of the embodiment of the present application converts the thermal energy contained in the waste gas into chemical energy contained in hydrogen gas for storage, thereby improving the quality of energy.

[0032] (2) The hydrogen cold combined production cement kiln waste heat utilization system of the embodiment of the present application uses the waste gas for methanol reforming hydrogen production reaction according to the height of the required waste gas temperature, and then uses the waste gas for the lithium bromide absorption refrigerator 14, thereby realizing the step-by-step utilization of energy.

[0033] (3) The hydrogen cold combined production cement kiln waste heat utilization system of the embodiment of the present application preheats the methanol raw material liquid by the methanol reforming hydrogen production reaction product outlet of the reactor 9, so that the heat contained in the reaction product is reasonably utilized, and the temperature of the reaction product is reduced, thereby reducing the volume of the cooler 10 required for cooling the reaction product and the amount of cooling water.

[0034] In the description of the present application, it is to be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are merely intended to facilitate the description of the present application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0035] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified and limited.

[0036] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or in communication with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the connection or interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0038] In this disclosure, the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" mean that a particular feature, structure, material, or characteristic is included in at least one embodiment or example of the present disclosure. The illustrative appearances of the above-mentioned terms in various places in the specification are not necessarily referred to the same embodiment or example. Moreover, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Furthermore, the terminology "comprising" is used in the disclosure as comprising, but not limited to, any indicated features, integers, steps or components. It is also to be understood that the terminology "comprising" can be replaced by the terminology "consisting of" or "consisting essentially of" in some embodiments or examples.

[0039] Although the above-mentioned embodiments have been shown and described, it is to be understood that the above-mentioned embodiments are exemplary, and should not be understood as limiting the present disclosure, and the changes, modifications, replacements and variations of the above-mentioned embodiments made by those skilled in the art are within the protection scope of the present disclosure.

Claims

1. A hydrogen-cooled cogeneration cement kiln waste heat utilization system, characterized in that, The application relates to a cement production system, which comprises a cement kiln production module, a hydrogen production module and a refrigeration module. The cement kiln production module comprises a raw material preheater, a rotary kiln and a clinker cooler connected in sequence, the raw material preheater is used for preheating cement raw material, the rotary kiln is used for calcining the preheated cement raw material to form cement clinker, and the clinker cooler is used for cooling the cement clinker. The hydrogen production module comprises a methanol hydrogen production loop, the methanol hydrogen production loop has a reactor and a gasifier, the raw material preheater is connected with a flue gas side inlet of the reactor, and the clinker cooler is connected with a hot side inlet of the gasifier. The methanol hydrogen production loop further comprises a feeding device, a preheater, a cooler, a gas-liquid separator, a pressure swing adsorber and a hydrogen storage tank. The feeding device is used for supplying methanol raw material liquid, the feeding device is connected with a cold side inlet of the preheater, a cold side outlet of the preheater is connected with a cold side inlet of the gasifier, a cold side outlet of the gasifier is connected with a shell side inlet of the reactor, a shell side outlet of the reactor is connected with a hot side inlet of the preheater, a hot side outlet of the preheater is connected with a hot side inlet of the cooler, a hot side outlet of the cooler is connected with an inlet of the gas-liquid separator, a gas side outlet of the gas-liquid separator is connected with an inlet of the pressure swing adsorber, and an outlet of the pressure swing adsorber is connected with an inlet of the hydrogen storage tank.

2. The hydrogen-cooled cogeneration system for cement kiln waste heat utilization according to claim 1, characterized in that, The reactor flue gas side outlet and the gasifier hot side outlet are connected with the refrigeration module.

3. The hydrogen-cooled cogeneration system of claim 2, wherein, The feeding device comprises a desalted water storage tank, a methanol storage tank and a methanol raw material liquid pump, the desalted water storage tank is used for storing desalted water, the methanol storage tank is used for storing methanol, and the desalted water in the desalted water storage tank is mixed with the methanol in the methanol storage tank in a certain proportion and then enters the methanol raw material liquid pump, and an outlet of the methanol raw material liquid pump is connected with the preheater cold side inlet.

4. The hydrogen-cooled cogeneration system of claim 1, wherein, A liquid side outlet of the gas-liquid separator is connected with the methanol raw material liquid pump inlet, and liquid material separated by the liquid side outlet of the gas-liquid separator can be introduced into the methanol raw material liquid pump inlet.

5. The hydrogen-cooled cogeneration system of claim 1, wherein, The shell side of the reactor is filled with catalysts required for methanol reforming hydrogen production reaction.

6. A hydrogen-cooled co-production system of cement kiln waste heat utilization system according to any one of claims 1-5, characterized in that, The raw material preheater is a cyclone preheater. The refrigeration module is a lithium bromide absorption refrigerator.

Images