CN115259990B - Method and system for recycling waste heat and emissions in acetylene production by calcium carbide method - Google Patents
Method and system for recycling waste heat and emissions in acetylene production by calcium carbide method Download PDFInfo
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- CN115259990B CN115259990B CN202210721774.8A CN202210721774A CN115259990B CN 115259990 B CN115259990 B CN 115259990B CN 202210721774 A CN202210721774 A CN 202210721774A CN 115259990 B CN115259990 B CN 115259990B
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- CLZWAWBPWVRRGI-UHFFFAOYSA-N tert-butyl 2-[2-[2-[2-[bis[2-[(2-methylpropan-2-yl)oxy]-2-oxoethyl]amino]-5-bromophenoxy]ethoxy]-4-methyl-n-[2-[(2-methylpropan-2-yl)oxy]-2-oxoethyl]anilino]acetate Chemical compound CC1=CC=C(N(CC(=O)OC(C)(C)C)CC(=O)OC(C)(C)C)C(OCCOC=2C(=CC=C(Br)C=2)N(CC(=O)OC(C)(C)C)CC(=O)OC(C)(C)C)=C1 CLZWAWBPWVRRGI-UHFFFAOYSA-N 0.000 title claims abstract description 153
- 239000005997 Calcium carbide Substances 0.000 title claims abstract description 151
- 238000000034 method Methods 0.000 title claims abstract description 141
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 title claims abstract description 86
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 title claims abstract description 86
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 58
- 239000002918 waste heat Substances 0.000 title claims abstract description 58
- 238000004064 recycling Methods 0.000 title claims abstract description 52
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims abstract description 290
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims abstract description 236
- 239000001569 carbon dioxide Substances 0.000 claims abstract description 145
- 229910002092 carbon dioxide Inorganic materials 0.000 claims abstract description 145
- 239000007789 gas Substances 0.000 claims abstract description 121
- 229910000019 calcium carbonate Inorganic materials 0.000 claims abstract description 118
- 239000002002 slurry Substances 0.000 claims abstract description 63
- 239000002893 slag Substances 0.000 claims abstract description 30
- 238000011084 recovery Methods 0.000 claims abstract description 26
- 239000002994 raw material Substances 0.000 claims abstract description 19
- 230000008569 process Effects 0.000 claims description 52
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 38
- 238000001179 sorption measurement Methods 0.000 claims description 28
- 238000001354 calcination Methods 0.000 claims description 23
- 238000010248 power generation Methods 0.000 claims description 23
- 230000001089 mineralizing effect Effects 0.000 claims description 15
- 238000001035 drying Methods 0.000 claims description 13
- 239000007787 solid Substances 0.000 claims description 13
- 238000009833 condensation Methods 0.000 claims description 10
- 230000005494 condensation Effects 0.000 claims description 10
- 238000001816 cooling Methods 0.000 claims description 10
- 230000005611 electricity Effects 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 4
- 238000005469 granulation Methods 0.000 claims description 3
- 230000003179 granulation Effects 0.000 claims description 3
- 238000002844 melting Methods 0.000 claims description 2
- 230000008018 melting Effects 0.000 claims description 2
- 239000002245 particle Substances 0.000 claims description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 5
- 229910052799 carbon Inorganic materials 0.000 abstract description 5
- 230000009467 reduction Effects 0.000 abstract description 5
- 239000002910 solid waste Substances 0.000 abstract description 5
- 230000008878 coupling Effects 0.000 abstract description 4
- 238000010168 coupling process Methods 0.000 abstract description 4
- 238000005859 coupling reaction Methods 0.000 abstract description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 6
- 239000000292 calcium oxide Substances 0.000 description 6
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 6
- 235000019738 Limestone Nutrition 0.000 description 4
- 239000006028 limestone Substances 0.000 description 4
- 238000010891 electric arc Methods 0.000 description 3
- 238000000465 moulding Methods 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000004568 cement Substances 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000004134 energy conservation Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000033558 biomineral tissue development Effects 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- MYFXBBAEXORJNB-UHFFFAOYSA-N calcium cyanamide Chemical compound [Ca+2].[N-]=C=[N-] MYFXBBAEXORJNB-UHFFFAOYSA-N 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C11/00—Aliphatic unsaturated hydrocarbons
- C07C11/22—Aliphatic unsaturated hydrocarbons containing carbon-to-carbon triple bonds
- C07C11/24—Acetylene
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/90—Carbides
- C01B32/914—Carbides of single elements
- C01B32/942—Calcium carbide
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K25/00—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for
- F01K25/08—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours
- F01K25/10—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours the vapours being cold, e.g. ammonia, carbon dioxide, ether
- F01K25/103—Carbon dioxide
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
- Y02P20/129—Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
Abstract
The invention relates to a method and a system for recovering waste heat and recycling emissions in acetylene production by a calcium carbide method, wherein the method comprises the following steps: preparing calcium carbonate slurry from carbide slag; carrying out heat exchange treatment on the molten calcium carbide by taking carbon dioxide gas as a cold source medium; after heat exchange treatment, the temperature of the cold source medium is increased to become carbon dioxide gas with a first temperature; carrying out heat exchange treatment on the calcium carbonate slurry by taking carbon dioxide gas with a first temperature as a heat source medium so as to dry the calcium carbonate slurry; wherein, the temperature of the heat source medium is reduced after heat exchange treatment, and the heat source medium becomes carbon dioxide gas with a second temperature; wherein, the carbon dioxide gas with the second temperature is used as the raw material in the step of preparing the calcium carbonate slurry to react with the carbide slag to prepare the calcium carbonate slurry. The invention is mainly used for creatively coupling the waste heat and the emissions in the acetylene production process by the calcium carbide method so as to realize the multiple purposes of waste heat recovery, carbon emission reduction and solid waste recycling.
Description
Technical Field
The invention relates to the technical field of acetylene production by a calcium carbide method, in particular to a method and a system for recovering waste heat and recycling emissions in acetylene production by a calcium carbide method.
Background
The technological route for producing acetylene by a calcium carbide method mainly comprises the following steps: calcining limestone (calcium carbonate) in a calcining kiln to crack the limestone into calcium oxide and carbon dioxide at high temperature; then, calcium oxide and C are used as raw materials to prepare calcium carbide in a calcium carbide furnace; finally, acetylene and carbide slag are prepared by taking calcium carbide and water as raw materials.
However, the inventor of the present invention found that the existing process for producing acetylene by the calcium carbide method has at least the following problems:
(1) The electric arc furnace (calcium carbide furnace) produces high temperature molten calcium carbide with a temperature as high as approximately 2000 ℃. In the existing production process, the molten calcium carbide is kept stand in a natural environment to be cooled and then solidified, but the sensible heat with high quality is completely wasted, and from the aspects of energy consumption, carbon neutralization and carbon peak, development of a technology for recovering the waste heat of the molten calcium carbide is needed.
In addition, calcium carbide can react with water severely, so that the contact with water is stopped in the transportation, storage and waste heat utilization processes; the high-temperature calcium carbide can react with nitrogen to generate lime nitrogen, so that the contact area of the molten calcium carbide with the nitrogen is controlled; because of the existence of nitrogen and humidity in the air, the formed high-temperature calcium carbide is prevented from contacting with the air due to the increase of the specific surface area, so that the threat of weathering is prevented. Therefore, the conventional waste heat utilization method is not suitable for recovering waste heat resources of the molten calcium carbide.
(2) In the calciner, limestone is cracked into calcium oxide and carbon dioxide at high temperature, so that the concentration of carbon dioxide in the exhaust gases from the calciner is relatively high, and if the calciner adopts the oxygen-enriched combustion technique, the concentration of carbon dioxide will further increase. The existing acetylene production process by the calcium carbide method does not recycle the carbon dioxide well.
(3) Regarding the recycling of carbide slag: in the prior art, carbide slag is mainly used as a cement raw material, but the utilization way of the carbide slag is urgently needed to be expanded in view of the industrial development of calcium carbide and acetylene due to the small required consumption of cement quality.
In summary, for the existing process for producing acetylene by using the calcium carbide method, a process and a system for recycling waste heat recovery and discharged products (carbon dioxide and carbide slag) are needed.
Disclosure of Invention
In view of the above, the invention provides a method and a system for recovering waste heat and recycling emission in acetylene production by a calcium carbide method, which mainly aim to realize waste heat recovery and recycling emission products in the acetylene production process by the calcium carbide method.
In order to achieve the above purpose, the present invention mainly provides the following technical solutions:
in one aspect, an embodiment of the present invention provides a method for recovering waste heat and recycling emissions in acetylene production by a calcium carbide method, wherein the method comprises the following steps:
the step of preparing calcium carbonate slurry: preparing calcium carbonate slurry from carbide slag;
and (3) cooling the molten calcium carbide: carrying out heat exchange treatment on the molten calcium carbide by taking carbon dioxide gas as a cold source medium; after heat exchange treatment, the temperature of the cold source medium is increased to become carbon dioxide gas at a first temperature;
and (3) a step of drying the calcium carbonate slurry: performing heat exchange treatment on the calcium carbonate slurry by taking the carbon dioxide gas with the first temperature as a heat source medium so as to dry the calcium carbonate slurry; wherein, the temperature of the heat source medium is reduced after heat exchange treatment, and the heat source medium becomes carbon dioxide gas with a second temperature;
wherein the carbon dioxide gas at the second temperature is used as a raw material in the step of preparing the calcium carbonate slurry to react with carbide slag to prepare the calcium carbonate slurry.
Preferably, in the step of cooling the molten calcium carbide: the cold source medium is derived from carbon dioxide tail gas generated by calcining calcium carbonate in the process of producing acetylene by a calcium carbide method (the tail gas discharged by calcining calcium carbonate is high-temperature, but the temperature of the tail gas is reduced after the tail gas is cooled and purified by a calcium carbonate preheater); preferably, the carbon dioxide tail gas generated by calcining calcium carbonate in the process of producing acetylene by a calcium carbide method is subjected to pressure swing adsorption treatment to obtain purified carbon dioxide gas; carrying out heat exchange treatment on the molten calcium carbide by taking the purified carbon dioxide gas as a cold source medium; preferably, the volume concentration of carbon dioxide in the carbon dioxide tail gas is 25-40%; preferably, the volume concentration of carbon dioxide in the purified carbon dioxide gas is more than or equal to 95%; preferably, the pressure swing adsorption process is a PSA pressure swing adsorption process.
Preferably, the temperature of the cold source medium is not more than 50 ℃;
preferably, the first temperature is 700-900 ℃.
Preferably, the second temperature is 70-150 ℃.
Preferably, in the calcium carbonate slurry drying step: drying the calcium carbonate slurry to obtain solid calcium carbonate; the solid calcium carbonate is used as a raw material in the process of producing acetylene by a calcium carbide method.
Preferably, in the step of cooling the molten calcium carbide: the heat exchange treatment is carried out on the molten calcium carbide, and the granulation treatment is carried out on the calcium carbide, so that the calcium carbide forms granular calcium carbide; preferably, the particle size of the granular calcium carbide is 5-80mm.
Preferably, the method further comprises:
the water vapor condensation treatment step: condensing the water vapor generated in the step of drying the calcium carbonate slurry to realize the recovery and the utilization of water resources; preferably, the carbon dioxide gas at the first temperature is divided into a first portion and a second portion; wherein the first portion is used as a heat source medium to perform heat exchange treatment on the calcium carbonate slurry; the second portion is used for generating electricity to power the water vapor condensation process; further preferably, the second part is cooled to a third temperature of carbon dioxide gas after power generation and utilization; wherein the carbon dioxide gas with the third temperature is used as a raw material in the step of preparing the calcium carbonate slurry and reacts with carbide slag to prepare the calcium carbonate slurry. Further preferably, the third temperature is 280-320 ℃, preferably 300 ℃.
On the other hand, the embodiment of the invention provides a waste heat recovery and emission recycling system in acetylene production by a calcium carbide method, wherein the system comprises:
the mineralizing device is used for preparing calcium carbonate slurry by taking carbide slag as a raw material;
the forming and heat exchanging device is used for carrying out heat exchanging treatment on the molten calcium carbide by taking carbon dioxide gas as a cold source medium; after heat exchange treatment, the temperature of the cold source medium is increased to become carbon dioxide gas at a first temperature;
the calcium carbonate upgrading device is used for carrying out heat exchange treatment on the calcium carbonate slurry output by the mineralizing device by taking the carbon dioxide gas at the first temperature as a heat source medium so as to dry the calcium carbonate slurry;
wherein, the carbon dioxide gas with the first temperature is subjected to heat exchange treatment in the calcium carbonate upgrading device, and then the temperature is reduced to become carbon dioxide gas with the second temperature; and the carbon dioxide gas with the second temperature is used for being conveyed into the mineralizing device to react with carbide slag to prepare calcium carbonate slurry.
Preferably, the system further comprises:
the pressure swing adsorption device is used for performing pressure swing adsorption treatment on carbon dioxide tail gas generated by calcining calcium carbonate in the process of producing acetylene by a calcium carbide method to obtain purified carbon dioxide gas; the pressure swing adsorption device is connected with the forming and heat exchanging device and is used for conveying the purified carbon dioxide gas into the forming and heat exchanging device so as to be used as a cold source medium for heat exchanging treatment of the molten calcium carbide; preferably, the pressure swing adsorption device is a PSA pressure swing adsorption device.
Preferably, the forming and heat exchanging device comprises a granulating structure, so that the calcium carbide is granulated while the molten calcium carbide is cooled, and the calcium carbide is formed into granular calcium carbide.
Preferably, the system further comprises:
and the water vapor condensing device is communicated with the water vapor output structure of the calcium carbonate upgrading device and is used for condensing the water vapor generated by the calcium carbonate upgrading device.
Preferably, the system further comprises:
the power generation device is connected with the steam condensing device and is used for providing power for the steam condensing device; preferably, the gas output structure on the forming and heat exchanging device is respectively connected with the power generation device and the calcium carbonate upgrading device, so that one part of the carbon dioxide gas with the first temperature is conveyed to the calcium carbonate upgrading device, and the other part of the carbon dioxide gas with the first temperature is conveyed to the power generation device; wherein the power generation device generates power by using carbon dioxide; further preferably, the carbon dioxide gas at the first temperature is cooled to become carbon dioxide gas at a third temperature for transportation to the mineralizing device after the carbon dioxide gas at the first temperature is generated and utilized by the power generation device.
In still another aspect, an embodiment of the present invention further provides a process system for producing acetylene by using a calcium carbide method, including a calcium carbonate calcining device, a calcium carbide producing device, and an acetylene producing device, where the process system for producing acetylene by using a calcium carbide method further includes: the waste heat recovery and emission recycling system in acetylene production by the calcium carbide method.
Compared with the prior art, the waste heat recovery and emission recycling method and system in acetylene production by the calcium carbide method have at least the following beneficial effects:
the method and the system for recovering waste heat and recycling emissions in acetylene production by a calcium carbide method provided by the embodiment of the invention are designed aiming at the process for producing acetylene by the calcium carbide method: preparing calcium carbonate slurry from the carbide slag as an emission; adopting discharged carbon dioxide gas as a cold source medium to exchange heat for the high-temperature molten calcium carbide to realize waste heat recovery, so as to obtain high-temperature carbon dioxide gas; the high temperature carbon dioxide gas is used for (at least partially) drying the calcium carbonate slurry to obtain pure calcium carbonate solid and low temperature carbon dioxide; the low-temperature carbon dioxide is used for mineralizing and reacting with the discharged carbide slag to generate solid calcium carbonate, and the generated solid calcium carbonate reenters a calcining kiln to be calcined to generate calcium oxide, so that the requirements of a calcium carbide production process on calcium carbonate raw materials are met, and industrial circulation of acetylene and calcium carbide production is formed. Preferably, the water vapor generated by drying the calcium carbonate slurry is condensed by a water vapor condensing device so as to realize the recovery of water resources. Further preferably, a portion of the high temperature carbon dioxide gas is used to generate electricity to power the water vapor condensing device. In conclusion, the scheme of the invention carries out innovative coupling according to the characteristics of waste heat and emissions in the process of producing acetylene by a calcium carbide method, and realizes the recovery of the waste heat and the recycling of emission products in the process of producing acetylene by the calcium carbide method, thereby realizing multiple advantages of environmental management, energy conservation, emission reduction, recycling of solid waste, and the like.
Further, the method and the system for recovering waste heat and recycling the discharged materials in the acetylene production by the calcium carbide method provided by the embodiment of the invention are used for granulating the high-temperature molten calcium carbide while adopting the cold source medium to exchange heat (i.e. recover waste heat) on the high-temperature molten calcium carbide so as to be directly used for acetylene production.
The foregoing description is only an overview of the present invention, and is intended to provide a better understanding of the present invention, as it is embodied in the following description, with reference to the preferred embodiments of the present invention and the accompanying drawings.
Drawings
Fig. 1 is a flow chart of a method for recovering waste heat and recycling emissions in acetylene production by a calcium carbide method according to an embodiment of the invention.
Detailed Description
In order to further describe the technical means and effects adopted for achieving the preset aim of the invention, the following detailed description refers to the specific implementation, structure, characteristics and effects according to the application of the invention with reference to the accompanying drawings and preferred embodiments. In the following description, different "an embodiment" or "an embodiment" do not necessarily refer to the same embodiment. Furthermore, the particular features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.
Example 1
On the one hand, as shown in fig. 1, the embodiment provides a method for recovering waste heat and recycling emissions in acetylene production by a calcium carbide method, which comprises the following steps:
the step of preparing calcium carbonate slurry: and preparing calcium carbide slag into calcium carbonate slurry.
Specifically, the discharge carbide slag (Ca (OH) in the acetylene production process by the calcium carbide method 2 ) And preparing calcium carbonate slurry by taking carbon dioxide as a raw material.
And (3) cooling the molten calcium carbide: carrying out heat exchange treatment on the molten calcium carbide by taking carbon dioxide gas as a cold source medium; wherein, after heat exchange treatment, the temperature of the cold source medium is increased to become carbon dioxide gas with a first temperature (namely, high-temperature carbon dioxide gas with a temperature of 700-900 ℃).
In the step, as the carbon dioxide has strong chemical stability under the conditions of no catalyst and the like and does not react with the calcium carbide, the carbon dioxide is considered to be used as a cold source medium to carry out direct contact heat exchange with the molten calcium carbide; preferably, the calcium carbide powder can be used as a powerful medium for calcium carbide forming or granulating.
Preferably, the source of the carbon dioxide gas in the step is carbon dioxide tail gas generated by calcining calcium carbonate in the process of producing acetylene by a calcium carbide method. Further, performing pressure swing adsorption treatment on carbon dioxide tail gas generated by calcining calcium carbonate in the process of producing acetylene by a calcium carbide method to obtain purified carbon dioxide gas; and carrying out heat exchange treatment on the molten calcium carbide by taking the purified carbon dioxide gas as a cold source medium. Preferably, the volume concentration of carbon dioxide in the carbon dioxide tail gas is 25-40%; preferably, the volume concentration of carbon dioxide in the purified carbon dioxide gas is more than or equal to 95%; preferably, the pressure swing adsorption process is a PSA pressure swing adsorption process.
Preferably, in the step of cooling the molten calcium carbide: the heat exchange treatment is carried out on the molten calcium carbide, and the granulation treatment is also carried out on the calcium carbide, so that the low-temperature granular calcium carbide is formed.
And (3) a step of drying the calcium carbonate slurry: heat exchanging the calcium carbonate slurry using a first temperature carbon dioxide gas (i.e., a high temperature carbon dioxide gas, preferably at least a portion of the high temperature carbon dioxide gas) as a heat source medium to dry the calcium carbonate slurry; wherein, the temperature of the heat source medium is reduced after heat exchange treatment to become carbon dioxide gas with a second temperature (namely, low-temperature carbon dioxide gas; the temperature is about 300 ℃). Wherein carbon dioxide gas at a second temperature (i.e., low-temperature carbon dioxide gas) is used as a raw material in the step of preparing the calcium carbonate slurry, and reacts with the carbide slag to prepare the calcium carbonate slurry. In addition, the calcium carbonate slurry is dried to obtain solid calcium carbonate; the solid calcium carbonate can directly enter a calcining kiln for calcining, thereby meeting the requirements of the calcium carbide production process on the calcium carbonate raw material.
The above steps proposed in this embodiment are described as follows:
as described in the background art, the existing acetylene production process by the calcium carbide method has the following problems: there is no technology for recovering the waste heat of the molten calcium carbide, and there is no way for well recovering and utilizing carbon dioxide and carbide slag to be expanded. Based on the above, the steps provided in this embodiment not only can realize recovery of waste heat of molten calcium carbide and recovery and utilization of emissions (carbon dioxide and carbide slag), but also can couple the waste heat recovery and recycling of emissions together innovatively, so as to form a circulating process route, and can better realize the purposes of waste heat recovery, carbon emission reduction and solid waste recycling in the acetylene production process by the carbide method.
Example 2
Preferably, as shown in fig. 1, the embodiment provides a method for recovering waste heat and recycling emissions in acetylene production by calcium carbide method, and compared with embodiment 1, the method further includes a water vapor condensation treatment step: and condensing steam generated in the step of drying the calcium carbonate slurry so as to realize recycling of water resources.
Preferably, the present embodiment further performs the following design: dividing the carbon dioxide gas (high-temperature carbon dioxide gas) at the first temperature obtained in the melting calcium carbide cooling step into a first part and a second part; wherein the first portion is used as a heat source medium to perform heat exchange treatment on the calcium carbonate slurry; the second part is used for generating electricity and providing power for the water vapor condensation treatment. Preferably, the second part is cooled to a third temperature of carbon dioxide gas (i.e. low-temperature carbon dioxide gas) after power generation and utilization; wherein the carbon dioxide gas of the third temperature (low-temperature carbon dioxide gas) is used as a raw material in the step of preparing the calcium carbonate slurry. In this embodiment, a power generation device using high-temperature carbon dioxide is further provided to provide power for the water vapor condensation treatment step, so that the recycling utilization is further realized, and the energy is saved.
Example 3
On the other hand, as shown in fig. 1, the embodiment of the invention also provides a waste heat recovery and emission recycling system in acetylene production by a calcium carbide method, which is used for implementing the methods described in the above embodiments 1-2. Wherein, waste heat recovery and emission recycling system in the carbide method production acetylene includes: mineralizing device 1, molding and heat exchanging device 2 and calcium carbonate upgrading device 3. Wherein, the mineralizing device 1 is used for preparing calcium carbonate slurry by taking discharged carbide slag as a raw material. The forming and heat exchanging device 2 is used for carrying out heat exchanging treatment on the molten calcium carbide by taking carbon dioxide gas as a cold source medium; wherein, after heat exchange treatment, the temperature of the cold source medium is increased to become carbon dioxide gas with a first temperature (namely, high-temperature carbon dioxide gas). The calcium carbonate upgrading device 3 is used for carrying out heat exchange treatment on the calcium carbonate slurry output by the mineralizing device 1 by taking carbon dioxide gas at a first temperature as a heat source medium so as to dry the calcium carbonate slurry. Wherein, the carbon dioxide gas (high temperature carbon dioxide gas) at the first temperature is subjected to heat exchange treatment in the calcium carbonate upgrading device 3, and then the temperature is reduced to become carbon dioxide gas (i.e. low temperature carbon dioxide gas) at the second temperature; the carbon dioxide gas at the second temperature (low-temperature carbon dioxide gas) is used for being conveyed into the mineralizing device 1 and reacts with carbide slag to prepare calcium carbonate slurry.
Preferably, the system further comprises a pressure swing adsorption device 5; the pressure swing adsorption device 5 is used for performing pressure swing adsorption treatment on carbon dioxide tail gas generated by calcining calcium carbonate in the process of producing acetylene by a calcium carbide method to obtain purified carbon dioxide gas. The pressure swing adsorption device 5 is connected with the forming and heat exchanging device 2 (preferably, through a pipeline connection, preferably, the pressure swing adsorption device 5 is connected with a heat exchanging system in the forming and heat exchanging device 2 through a pipeline) and is used for conveying purified carbon dioxide gas into the forming and heat exchanging device 2 so as to be used as a cold source medium for heat exchanging treatment of molten calcium carbide. Preferably, PSA pressure swing adsorption device is used as pressure swing adsorption device 5.
In summary, the system for recovering waste heat and recycling the emissions in the acetylene production by the calcium carbide method provided by the embodiment not only can realize recovery of the waste heat of the molten calcium carbide and recycling of the emissions (carbon dioxide and carbide slag), but also can realize recovery of the waste heat, carbon emission reduction and solid waste recycling in the acetylene production by the calcium carbide method by coupling the waste heat recovery and the recycling of the emissions together to form a circulating process.
Preferably, the forming and heat exchanging device 2 comprises a granulating structure, so that the molten calcium carbide is cooled and simultaneously granulated, so that the low-temperature granular calcium carbide is formed and is directly used for acetylene production.
Example 4
Preferably, as shown in fig. 1, the embodiment provides a system for recovering waste heat and recycling emissions in acetylene production by calcium carbide, and compared with embodiment 3, the embodiment further designs a water vapor condensing device 4; wherein, the steam condensing device 4 is communicated with the steam output structure of the calcium carbonate upgrading device 3 and is used for condensing the steam generated by the calcium carbonate upgrading device 3 (in the calcium carbonate upgrading device 3, the steam is generated due to the drying of the calcium carbonate slurry).
Preferably, the system further comprises a power generation device 6, wherein the power generation device 6 is connected to the water vapor condensation device 4 for powering the water vapor condensation device 4.
Preferably, the gas output structure on the forming and heat exchanging device 2 is respectively connected with the power generation device 6 and the calcium carbonate upgrading device 3, so that one part of the carbon dioxide gas (high-temperature carbon dioxide) with the first temperature is conveyed to the calcium carbonate upgrading device 3, and the other part of the carbon dioxide gas is conveyed to the power generation device 6; the power generation device 6 generates power using high-temperature carbon dioxide. Preferably, the carbon dioxide gas (high-temperature carbon dioxide) at the first temperature is used as the carbon dioxide gas (low-temperature carbon dioxide) at the third temperature after being generated and utilized by the power generation device 6, and is used for being sent to the mineralization device 1.
In this embodiment, the embodiment further provides a water vapor condensing device 4 on the basis of embodiment 3, so as to condense the water vapor generated by the calcium carbonate upgrading device 3, thereby realizing recycling of water resources, and the recycled condensed water can be used with high quality. Preferably, the embodiment further provides a power generation device utilizing high-temperature carbon dioxide to provide power for the water vapor condensation treatment step, thereby further realizing the utilization of resources and saving energy.
Example 5
In still another aspect, the embodiment further provides a process system for producing acetylene by using a calcium carbide method, which comprises a calcium carbonate calcining device 7, a calcium carbide producing device 8 and an acetylene producing device 9, wherein the process system for producing acetylene by using a calcium carbide method further comprises: the waste heat recovery and emission recycling system in acetylene production by the calcium carbide method described in the above embodiment 3 or embodiment 4.
Here, since the process system for producing acetylene by the calcium carbide method provided in the embodiment includes the waste heat recovery and emission recycling system in producing acetylene by the calcium carbide method, the process system for producing acetylene by the calcium carbide method in the embodiment has the beneficial effects of the embodiment described above, and the description thereof is not repeated here.
The working procedure of the calcium carbide method acetylene production process system of the embodiment is described in detail below:
as shown in fig. 1, in the process of producing acetylene by a calcium carbide method, limestone (calcium carbonate) enters a calcining kiln (a calcium carbonate calcining device 7) and is calcined at high temperature to generate calcium oxide and high-concentration carbon dioxide tail gas (wherein the concentration of carbon dioxide in the tail gas ranges from 25% to 40%). Wherein, the generated calcium oxide and coke are proportioned and then enter an electric arc furnace (a calcium carbide production device 8) to react at a high temperature of more than 2000 ℃ under the heating of an electrode rod to generate calcium carbide.
When the electric arc furnace (the calcium carbide production device 8) is used for producing the calcium carbide, the temperature of the produced high-temperature molten calcium carbide is up to 2000 ℃. The carbon dioxide tail gas discharged from the calcining kiln (the calcium carbonate calcining device 7) is subjected to pressure swing adsorption treatment by the pressure swing adsorption device 5, and then the concentration of the carbon dioxide is further increased, so that purified carbon dioxide gas is obtained.
In the molding and heat exchanging device 2, the purified carbon dioxide gas is used as a cold source medium to directly contact and exchange heat with the high-temperature molten calcium carbide, and the carbon dioxide gas (high-temperature carbon dioxide gas) with the first temperature is obtained after heat exchange treatment. In addition, the calcium carbide is granulated and molded in the heat exchange process, so that the granular calcium carbide which can be directly used for acetylene production is obtained.
The granular calcium carbide reacts with water in an acetylene generator (acetylene production device 9) to generate acetylene products, and meanwhile, discharged carbide slag is generated. In the mineralizing device 1, the discharged carbide slag reacts with carbon dioxide to obtain calcium carbonate slurry.
In the calcium carbonate upgrading device 3, a part of carbon dioxide gas (high-temperature carbon dioxide gas) at a first temperature is used for drying the calcium carbonate slurry to obtain high-purity solid calcium carbonate (the high-purity solid calcium carbonate can directly enter a calcining kiln for calcining, so that the requirement of calcium carbide production is met). The vapor generated by drying the calcium carbonate slurry enters a vapor condensing device 4 for condensing, and the obtained pure condensed water can be used in a high-quality manner. Wherein the power required by the water vapor condensing device 4 is derived from a power generation device (the power generation device generates power by using another part of the carbon dioxide gas at the first temperature).
Specifically, the use of the carbon dioxide gas (high-temperature carbon dioxide gas) at the first temperature output by the molding and heat exchanging device 2 is divided into two parts, and one part enters the calcium carbonate upgrading device 3; the other part is used for generating electricity and providing power for the water vapor condensing device 4. After heat utilization, the temperature of the dioxide is reduced, and the obtained low-temperature carbon dioxide enters the mineralizing device 2 to react with carbide slag to prepare calcium carbonate slurry.
In summary, the scheme of the embodiment of the invention carries out innovative coupling according to the characteristics of waste heat and emissions in the process of producing acetylene by a calcium carbide method, and realizes the recovery of the waste heat and the recycling of the emission products in the process of producing acetylene by the calcium carbide method, thereby realizing multiple advantages of environmental management, energy conservation, emission reduction, recycling of solid waste and the like.
The above description is only of the preferred embodiments of the present invention, and is not intended to limit the present invention in any way, but any simple modification, equivalent variation and modification made to the above embodiments according to the technical substance of the present invention still fall within the scope of the technical solution of the present invention.
Claims (17)
1. A method for recovering waste heat and recycling emissions in acetylene production by a calcium carbide method is characterized by comprising the following steps:
the step of preparing calcium carbonate slurry: preparing calcium carbonate slurry from carbide slag;
and (3) cooling the molten calcium carbide: carrying out heat exchange treatment on the molten calcium carbide by taking carbon dioxide gas as a cold source medium; after heat exchange treatment, the temperature of the cold source medium is increased to become carbon dioxide gas at a first temperature; performing pressure swing adsorption treatment on carbon dioxide tail gas generated by calcining calcium carbonate in the process of producing acetylene by a calcium carbide method to obtain purified carbon dioxide gas; carrying out heat exchange treatment on the molten calcium carbide by taking the purified carbon dioxide gas as a cold source medium;
and (3) a step of drying the calcium carbonate slurry: performing heat exchange treatment on the calcium carbonate slurry by taking the carbon dioxide gas with the first temperature as a heat source medium so as to dry the calcium carbonate slurry; wherein, the temperature of the heat source medium is reduced after heat exchange treatment, and the heat source medium becomes carbon dioxide gas with a second temperature;
wherein the carbon dioxide gas with the second temperature is used as a raw material in the step of preparing the calcium carbonate slurry to react with carbide slag to prepare the calcium carbonate slurry;
wherein, the calcium carbonate slurry is dried to obtain solid calcium carbonate; the solid calcium carbonate is used as a raw material in the process of producing acetylene by a calcium carbide method.
2. The method for recovering waste heat and recycling emissions in the production of acetylene by a calcium carbide process according to claim 1, wherein in the step of cooling the molten calcium carbide:
the volume concentration of carbon dioxide in the carbon dioxide tail gas is 25-40%; and/or
The volume concentration of carbon dioxide in the purified carbon dioxide gas is more than or equal to 95 percent; and/or
The pressure swing adsorption process is a PSA pressure swing adsorption process.
3. The method for recovering waste heat and recycling the emissions in the production of acetylene by a calcium carbide method according to claim 1, which is characterized in that,
the temperature of the cold source medium is not more than 50 ℃; and/or
The first temperature is 700-900 ℃; and/or
The second temperature is 70-150 ℃; and/or
In the melting calcium carbide cooling step: the heat exchange treatment is carried out on the molten calcium carbide, and the granulation treatment is also carried out on the calcium carbide, so that the calcium carbide forms granular calcium carbide.
4. The method for recovering waste heat and recycling emissions in the production of acetylene by a calcium carbide process according to any one of claims 1 to 3, further comprising:
the water vapor condensation treatment step: condensing the water vapor generated in the step of drying the calcium carbonate slurry to realize the recovery and the utilization of water resources.
5. The method for recovering waste heat and recycling the emissions in the production of acetylene by a calcium carbide process according to claim 4, wherein the carbon dioxide gas at the first temperature is divided into a first part and a second part; wherein the first portion is used as a heat source medium to perform heat exchange treatment on the calcium carbonate slurry; the second portion is used to generate electricity to power the condensation process.
6. The method for recovering waste heat and recycling the emissions in the production of acetylene by a calcium carbide process according to claim 5, wherein the second part is cooled to carbon dioxide gas at a third temperature after power generation and utilization; wherein the carbon dioxide gas with the third temperature is used as a raw material in the step of preparing the calcium carbonate slurry and reacts with carbide slag to prepare the calcium carbonate slurry.
7. The method for recovering waste heat and recycling the emissions in the production of acetylene by a calcium carbide process according to claim 6, wherein the third temperature is 280-320 ℃.
8. The method for recovering waste heat and recycling the emissions in the production of acetylene by a calcium carbide process according to claim 7, wherein the third temperature is 300 ℃.
9. Waste heat recovery and emission recycling system in acetylene production by calcium carbide method, which is characterized by comprising:
the mineralizing device is used for preparing calcium carbonate slurry by taking carbide slag as a raw material;
the forming and heat exchanging device is used for carrying out heat exchanging treatment on the molten calcium carbide by taking carbon dioxide gas as a cold source medium; after heat exchange treatment, the temperature of the cold source medium is increased to become carbon dioxide gas at a first temperature;
the calcium carbonate upgrading device is used for carrying out heat exchange treatment on the calcium carbonate slurry output by the mineralizing device by taking the carbon dioxide gas at the first temperature as a heat source medium so as to dry the calcium carbonate slurry; wherein, the calcium carbonate slurry is dried to obtain solid calcium carbonate; the solid calcium carbonate is used as a raw material in the process of producing acetylene by a calcium carbide method;
wherein, the carbon dioxide gas with the first temperature is subjected to heat exchange treatment in the calcium carbonate upgrading device, and then the temperature is reduced to become carbon dioxide gas with the second temperature; the carbon dioxide gas with the second temperature is used for being conveyed into the mineralizing device and reacts with carbide slag to prepare calcium carbonate slurry;
wherein the system further comprises:
the pressure swing adsorption device is used for performing pressure swing adsorption treatment on carbon dioxide tail gas generated by calcining calcium carbonate in the process of producing acetylene by a calcium carbide method to obtain purified carbon dioxide gas;
the pressure swing adsorption device is connected with the forming and heat exchanging device and is used for conveying the purified carbon dioxide gas into the forming and heat exchanging device so as to be used as a cold source medium for heat exchanging treatment of the molten calcium carbide.
10. The system for recovering waste heat and recycling the discharged materials in the production of acetylene by a calcium carbide method according to claim 9, wherein the pressure swing adsorption device is a PSA pressure swing adsorption device.
11. The system for recovering waste heat and recycling the discharged materials in the production of acetylene by a calcium carbide method according to claim 9, wherein the forming and heat exchanging device comprises a granulating structure for granulating the calcium carbide while cooling the molten calcium carbide to form granular calcium carbide.
12. The system for recovering waste heat and recycling the discharged materials in the production of acetylene by a calcium carbide process according to claim 11, wherein the particle size of the granular calcium carbide is 5-80mm.
13. The waste heat recovery and effluent reclamation system in the production of acetylene by a calcium carbide process according to any one of claims 9 to 12, wherein the system further comprises:
and the water vapor condensing device is communicated with the water vapor output structure of the calcium carbonate upgrading device and is used for condensing the water vapor generated by the calcium carbonate upgrading device.
14. The system for recovering waste heat and recycling emissions in the production of acetylene by a calcium carbide process according to claim 13, wherein the system further comprises:
and the power generation device is connected with the water vapor condensing device to provide power for the water vapor condensing device.
15. The system for recovering waste heat and recycling emissions in acetylene production by a calcium carbide process according to claim 14, wherein a gas output structure on the forming and heat exchanging device is respectively connected with the power generation device and the calcium carbonate upgrading device so as to convey one part of the carbon dioxide gas with the first temperature to the calcium carbonate upgrading device and the other part to the power generation device; wherein the power generation device generates power by using carbon dioxide.
16. The system for recovering waste heat and recycling the emissions in the production of acetylene by a calcium carbide process according to claim 15, wherein the carbon dioxide gas at the first temperature is cooled to a carbon dioxide gas at a third temperature for being conveyed to the mineralizing device after being subjected to power generation and utilization by the power generating device.
17. The utility model provides a carbide method production acetylene process systems, includes calcium carbonate calcination device, carbide apparatus for producing, acetylene apparatus for producing, its characterized in that, carbide method production acetylene process systems still includes: the waste heat recovery and effluent recycling system in acetylene production by a calcium carbide process according to any one of claims 9 to 16.
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| CN108675911A (en) * | 2018-08-21 | 2018-10-19 | 中国科学院上海高等研究院 | A kind of carbide acetylene production technology for reducing carbide slag and generating |
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| CN1986458A (en) * | 2006-12-12 | 2007-06-27 | 梁永洪 | Carbide residue and waste water treating process |
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| CN203333536U (en) * | 2013-07-08 | 2013-12-11 | 广西德陆科技有限公司 | Device for recycling acetylene gas from carbide slag slurry |
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