CN114057277A - Waste alkali wet oxidation system and method - Google Patents
Waste alkali wet oxidation system and method Download PDFInfo
- Publication number
- CN114057277A CN114057277A CN202010770185.XA CN202010770185A CN114057277A CN 114057277 A CN114057277 A CN 114057277A CN 202010770185 A CN202010770185 A CN 202010770185A CN 114057277 A CN114057277 A CN 114057277A
- Authority
- CN
- China
- Prior art keywords
- heat
- oxygen
- conducting medium
- heat exchanger
- containing gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003513 alkali Substances 0.000 title claims abstract description 129
- 239000002699 waste material Substances 0.000 title claims abstract description 129
- 238000000034 method Methods 0.000 title claims abstract description 61
- 238000009279 wet oxidation reaction Methods 0.000 title claims abstract description 60
- 239000007789 gas Substances 0.000 claims abstract description 148
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 115
- 239000001301 oxygen Substances 0.000 claims abstract description 115
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 107
- 238000006243 chemical reaction Methods 0.000 claims abstract description 67
- 239000007795 chemical reaction product Substances 0.000 claims abstract description 44
- 239000000047 product Substances 0.000 claims abstract description 36
- 238000000926 separation method Methods 0.000 claims abstract description 16
- 238000011144 upstream manufacturing Methods 0.000 claims abstract description 10
- 238000012546 transfer Methods 0.000 claims description 57
- 239000003518 caustics Substances 0.000 claims description 33
- 239000002994 raw material Substances 0.000 claims description 33
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 31
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 claims description 24
- 238000007254 oxidation reaction Methods 0.000 claims description 24
- 230000008569 process Effects 0.000 claims description 21
- 239000007791 liquid phase Substances 0.000 claims description 16
- 238000002347 injection Methods 0.000 claims description 9
- 239000007924 injection Substances 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 9
- 239000012071 phase Substances 0.000 claims description 7
- 238000007667 floating Methods 0.000 claims description 5
- 238000005086 pumping Methods 0.000 claims description 5
- 150000003839 salts Chemical class 0.000 claims description 5
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 4
- 150000001875 compounds Chemical class 0.000 claims description 4
- -1 ketone compounds Chemical class 0.000 claims description 4
- 150000002989 phenols Chemical class 0.000 claims description 4
- 229910052717 sulfur Inorganic materials 0.000 claims description 4
- 239000011593 sulfur Substances 0.000 claims description 4
- 238000001514 detection method Methods 0.000 claims description 3
- 150000001555 benzenes Chemical class 0.000 claims description 2
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims description 2
- 239000007788 liquid Substances 0.000 abstract description 14
- 238000005265 energy consumption Methods 0.000 abstract description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 63
- 235000011121 sodium hydroxide Nutrition 0.000 description 27
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 19
- 239000000126 substance Substances 0.000 description 18
- 229910052979 sodium sulfide Inorganic materials 0.000 description 16
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 16
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 11
- 239000005977 Ethylene Substances 0.000 description 11
- 239000010865 sewage Substances 0.000 description 10
- 239000000203 mixture Substances 0.000 description 9
- 230000003647 oxidation Effects 0.000 description 8
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 5
- 238000001816 cooling Methods 0.000 description 5
- 238000006386 neutralization reaction Methods 0.000 description 5
- 230000009467 reduction Effects 0.000 description 5
- 238000007670 refining Methods 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 4
- 238000007599 discharging Methods 0.000 description 4
- 239000010815 organic waste Substances 0.000 description 4
- 229920006395 saturated elastomer Polymers 0.000 description 4
- 150000004763 sulfides Chemical class 0.000 description 4
- 239000013589 supplement Substances 0.000 description 4
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 229910000029 sodium carbonate Inorganic materials 0.000 description 3
- YNQLUTRBYVCPMQ-UHFFFAOYSA-N Ethylbenzene Chemical compound CCC1=CC=CC=C1 YNQLUTRBYVCPMQ-UHFFFAOYSA-N 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 238000003763 carbonization Methods 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 239000000498 cooling water Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 125000001741 organic sulfur group Chemical group 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 230000020477 pH reduction Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- BWGNESOTFCXPMA-UHFFFAOYSA-N Dihydrogen disulfide Chemical compound SS BWGNESOTFCXPMA-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 235000014121 butter Nutrition 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000004939 coking Methods 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000004332 deodorization Methods 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910017053 inorganic salt Inorganic materials 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- CRVGTESFCCXCTH-UHFFFAOYSA-N methyl diethanolamine Chemical compound OCCN(C)CCO CRVGTESFCCXCTH-UHFFFAOYSA-N 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000011949 solid catalyst Substances 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/72—Treatment of water, waste water, or sewage by oxidation
- C02F1/727—Treatment of water, waste water, or sewage by oxidation using pure oxygen or oxygen rich gas
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/02—Treatment of water, waste water, or sewage by heating
- C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
- C02F1/06—Flash evaporation
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/34—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/34—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32
- C02F2103/36—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 from the manufacture of organic compounds
- C02F2103/365—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 from the manufacture of organic compounds from petrochemical industry (e.g. refineries)
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/02—Temperature
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/03—Pressure
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Treatment Of Water By Oxidation Or Reduction (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to the technical field of wet oxidation of waste alkali, and discloses a wet oxidation system and a wet oxidation method for waste alkali, wherein an oxygen-containing gas supply system in the system comprises at least one oxygen-containing gas conveying pipeline, at least two oxygen-containing gas inlets are arranged on a waste alkali liquid conveying pipeline of the waste alkali liquid supply system, and the oxygen-containing gas conveying pipeline is connected with the oxygen-containing gas inlets; the waste alkali liquor conveying pipeline is connected with a reactor of the reaction system, and a reaction product outlet pipeline of the reactor is connected with a product separation system; the heat-conducting medium circulating pipeline of the heat-conducting medium heat exchange system is connected with the reaction product outlet pipeline through a heat-conducting medium/reaction product heat exchanger, the heat-conducting medium circulating pipeline is connected with the waste alkali liquor conveying pipeline through a heat-conducting medium/feeding heat exchanger, and the oxygen-containing gas inlets are arranged at the upstream and the downstream of the heat-conducting medium/feeding heat exchanger and on the optional heat-conducting medium/feeding heat exchanger. The system and the method have the advantages of low energy consumption, no blockage of pipelines and equipment and stable operation of the device.
Description
Technical Field
The invention relates to the technical field of wet oxidation of spent caustic soda, in particular to a system and a method for wet oxidation of spent caustic soda.
Background
Sodium hydroxide is usually used in the processing of coal chemical industry, petrochemical industry and the like to remove sulfides and acidic substances in oil products, so that a large amount of waste alkali liquor is generated. The waste alkali liquor has the characteristics of complex components, high COD (chemical oxygen demand), difficult degradation and the like, and simultaneously contains high-concentration inorganic salts, sulfides, sodium hydroxide, benzene, phenols, petroleum and other harmful substances.
At present, the treatment method of waste alkali liquor mainly includes three methods of wet oxidation method, neutralization method and incineration method. The wet oxidation method is to convert the disulfide in the waste alkali into sulfide and organic matter into water and carbon dioxide by using oxygen as oxidant under the condition of high temperature and high pressure, so as to achieve the aim of deodorization or harmlessness. The wet oxidation method has the advantages of high conversion efficiency, high equipment material, large investment, high operation energy consumption and limited capability of removing partial organic matters and COD. The neutralization method is to utilize the acid-base neutralization principle and utilize added acid to neutralize the waste alkali, the generated gas is burned by a torch, and the neutralized liquid phase is sent to a sewage treatment plant for treatment. The neutralization method has the advantages of simple treatment process and has the disadvantage that the neutralized waste alkali liquor has high salt content and has larger impact on downstream sewage treatment plants. The incineration method is to convert organic matters into water and carbon dioxide, sulfides into sulfates and sodium hydroxide into sodium carbonate in an incinerator under the conditions of normal pressure and high temperature. The burning method has the advantages of simple operation, short flow, standard emission and large energy consumption and investment.
In recent years, with the rapid development of coal chemical industry and petrochemical industry, researchers and engineers at home and abroad develop corresponding treatment processes aiming at specific waste alkali liquor through continuous research, development and improvement, so that the technical field of waste alkali treatment is a new step. Such as: the companies of Japan, Germany and America have successively developed wet oxidation treatment technology of spent lye, which is the essence of oxidizing sulfides in the spent lye into sulfates. China also develops a plurality of treatment processes, such as: acidification process, carbonization process, etc. For the acidification process, the recovery of high-value substances (such as phenols) in the spent caustic is emphasized; the carbonization process mainly solves the problem of neutralization of the waste alkali liquor to ensure that Na in the waste alkali liquor2Decomposition of S to H2And S. The two processes have advantages and disadvantages, the application range of the two processes to the waste alkali liquor is narrow, and the process technology per se is not mature.
Patent document cn201310537919.x discloses a treatment method of oil refining waste lye for treating catalytic gasoline and liquid alkali-stop washing waste lye, which has the disadvantage of high operation energy consumption. Patent document CN102046538A discloses a catalytic wet oxidation system and method for treating the substances to be oxidized in waste lye by using a particulate solid catalyst, which has high efficiency in removing the substances to be oxidized, and has the disadvantages that the solid particulate catalyst is easy to block pipelines and equipment, and easy to abrade the equipment and pipelines, and accordingly, the investment of the equipment and the pipelines is increased. The patent document with the application number of 201811583460.6 discloses a treatment method and a treatment system of waste alkali liquid, the method firstly adopts active carbon to adsorb organic matters in the waste alkali liquid, then uses organic solvent to mix with low organic waste alkali liquid, so that inorganic salt which is insoluble in the organic solvent is separated out from the low organic waste alkali, and finally carries out solid-liquid separation. Patent document CN106573227B discloses a wet air oxidation system and process without scaling, which can solve the scaling problem in the treatment process and can not effectively solve the problems of high investment and energy consumption. Patent document CN108675537A discloses a method and a process system for treating sulfide-containing organic waste alkali solution, in which a complexation method is used to precipitate sulfide, and Fenton is used to degrade refractory substances such as sulfide, organic sulfur, benzene ring and the like in the organic waste alkali solution, and the disadvantages of complex operation, long process flow and high energy consumption are included. Patent document CN106587470A discloses a method and a process system for harmless treatment of high-salt high-COD waste lye, which solves the problem of high salt content in the waste lye, and due to the use of a catalyst, the problems of pipeline blockage, large amount of waste residue and the like easily occur, and simultaneously benzene and organic sulfur substances cannot be effectively degraded.
In the prior art, the waste alkali reaction feeding and discharging usually adopts direct heat exchange, which is beneficial to energy utilization, and has the problems that the temperature of the tube wall of a heat exchange tube is high due to the direct heat exchange of reaction raw materials and products, the feeding side is easy to scale and block, and the heat exchange efficiency and the long-period operation time are reduced. In addition, the prior art has carried out the exploration in different angles, different fields to the alkali waste oxidation field, and whether the sulphide, the COD material that need be oxidized in the waste lye can be got rid of smoothly, reaches energy saving and emission reduction, confirms the steady operation of device, is the problem that technical staff in the field need solve urgently.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a waste alkali wet oxidation system and a waste alkali wet oxidation method, which solve the defects that a replacement heat pipe in the prior art is easy to scale and block, high in operation energy consumption, poor in oxidation effect, unstable in operation, small in operation elasticity, difficult to control and the like.
The first aspect of the invention provides a spent caustic wet oxidation system, which comprises a reaction raw material feeding system, a reaction system, a heat-conducting medium heat exchange system and a product separation system;
the reaction raw material feeding system comprises an oxygen-containing gas supply system and a waste alkali liquor supply system, the oxygen-containing gas supply system comprises at least one oxygen-containing gas conveying pipeline, the waste alkali liquor supply system comprises a waste alkali liquor conveying pipeline, at least two oxygen-containing gas inlets are formed in the waste alkali liquor conveying pipeline, and the oxygen-containing gas conveying pipeline is connected with the oxygen-containing gas inlets;
the reaction system comprises a reactor, the discharge end of the waste alkali liquor conveying pipeline is connected with a reaction raw material inlet at the bottom of the reactor, a reaction product outlet pipeline is arranged at the top of the reactor, and the discharge end of the reaction product outlet pipeline is connected with a product separation system;
the heat-conducting medium heat exchange system comprises a heat-conducting medium circulating pipeline, the heat-conducting medium circulating pipeline is connected with a reaction product outlet pipeline through a heat-conducting medium/reaction product heat exchanger, and the heat-conducting medium circulating pipeline is connected with a waste alkali liquor conveying pipeline through a heat-conducting medium/feeding heat exchanger;
the oxygen-containing gas inlets are located upstream of the heat transfer medium/feed heat exchanger, downstream of the heat transfer medium/feed heat exchanger, and optionally on the heat transfer medium/feed heat exchanger.
A second aspect of the present invention provides a spent caustic wet oxidation method using the above-described spent caustic wet oxidation system, the spent caustic wet oxidation method including the steps of:
a) the pressure of the oxygen-containing gas is increased to obtain compressed gas, and the pressure of the waste alkali liquor is increased to obtain pressure-increased waste alkali liquor;
b) the compressed gas is mixed with the boosted waste alkali liquor through at least two oxygen-containing gas inlets on a waste alkali liquor conveying pipeline, meanwhile, the materials are subjected to heat exchange and temperature rise with the heated heat-conducting medium through a heat-conducting medium/feeding heat exchanger to obtain reaction raw materials, and the reaction raw materials are fed into a reactor for oxidation reaction;
c) and pumping the heat-conducting medium to become the heat-conducting medium after temperature rise, and circulating the heat-conducting medium to a heat-conducting medium/feeding heat exchanger to exchange heat with the reaction raw material.
Compared with the prior art, the invention has the beneficial effects that:
1. according to the waste alkali wet oxidation system and the waste alkali wet oxidation method, the heat transfer medium heat exchange system is arranged, direct heat exchange of feeding and discharging materials is avoided, the temperature of the heat transfer medium can be flexibly adjusted by controlling the flow of the heat transfer medium, the purpose of adjusting and controlling the wall temperature of the heat exchange tube is achieved, the problem that the feeding side is easy to scale and block is fundamentally solved, the heat exchange efficiency is improved, and the long-period stable operation time is prolonged.
2. According to the waste alkali wet oxidation system and the waste alkali wet oxidation method, the plurality of oxygen-containing gas inlets are arranged, the oxygen-containing gas can be respectively injected into the front and the back of the heat-conducting medium/feeding heat exchanger, the flow of the oxygen-containing gas can be adjusted according to different feeding compositions, and the oxygen content and the pressure of the oxygen-containing gas can be selected according to different feeding working conditions before and after entering the heat exchanger, so that the operation flexibility of the device is further increased, and the risk of easy scaling and blockage of the heat-conducting medium/feeding heat exchanger is reduced.
3. According to the wet oxidation system and method for the waste alkali, the steam inlet is formed in the bottom of the reactor, so that on one hand, required heat can be provided for the initial stage of reaction, on the other hand, when the temperature in the reactor is low, steam can be supplemented to the reactor through the temperature control loop to improve the material temperature, the oxidation reaction is accelerated, and the complete reaction of oxide substances to be oxidized is ensured.
4. The wet oxidation system and the wet oxidation method for the waste alkali have the advantages of large waste alkali liquid treatment amount, strong applicability, stable device operation, low energy consumption and operation cost, small occupied area and the like.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without limiting the invention.
FIG. 1 is a schematic view of the configuration of a spent caustic wet oxidation system according to example 1 of the present invention.
FIG. 2 is a schematic view of the structure of a spent caustic wet oxidation system according to example 2 of the present invention.
FIG. 3 is a schematic view of the structure of a spent caustic wet oxidation system according to example 3 of the present invention.
FIG. 4 is a schematic view of the structure of a spent caustic wet oxidation system according to example 4 of the present invention.
FIG. 5 is a schematic view of the structure of a spent caustic wet oxidation system according to example 5 of the present invention.
FIG. 6 is a schematic view showing the structure of a spent caustic wet oxidation system according to example 6 of the present invention.
FIG. 7 is a schematic view of the configuration of a spent caustic wet oxidation system according to example 7 of the present invention.
Fig. 8 is a schematic structural view of a double pipe heat exchanger in embodiment 6 of the present invention.
Description of the reference numerals
1-oxygen-containing gas, 2-compressed gas, 3-warming gas, 3 a-first compressed gas, 3 b-second compressed gas, 3 c-third compressed gas,
4-waste alkali liquor, 5-boosting waste alkali liquor, 6-low oxygen-containing waste alkali liquor after heat exchange, 7-reaction product, 8-reaction product after temperature reduction, 9-liquid-phase product, 10-liquid-phase product after cooling, 11-gas-phase product, 12-steam, 13-cooling water, 14-low oxygen-containing waste alkali liquor, 15-high oxygen-containing waste alkali liquor,
20-pumping heat-conducting medium, 21-heating up heat-conducting medium, 22-cooling down heat-conducting medium,
101-gas compressor, 102-reactor, 103-waste lye tank, 104-feed pump, 105-heat-conducting medium/feed heat exchanger, 106-flash tank, 107-water cooler, 108-gas/heat-conducting medium heat exchanger, 109-heat-conducting medium/reaction product heat exchanger, 110-heat-conducting medium buffer tank, 111-heat-conducting medium circulating pump,
301-distributor, 302-inner annular flow bucket.
Detailed Description
In order that the present invention may be more readily understood, the following detailed description of the invention is given with reference to the accompanying drawings and embodiments, which are given by way of illustration only and are not intended to limit the invention.
According to a first aspect of the present invention, the present invention provides a spent caustic wet oxidation system, comprising a reaction raw material feeding system, a reaction system, a heat transfer medium heat exchange system and a product separation system;
the reaction raw material feeding system comprises an oxygen-containing gas supply system and a waste alkali liquor supply system, the oxygen-containing gas supply system comprises at least one oxygen-containing gas conveying pipeline, the waste alkali liquor supply system comprises a waste alkali liquor conveying pipeline, at least two oxygen-containing gas inlets are formed in the waste alkali liquor conveying pipeline, and the oxygen-containing gas conveying pipeline is connected with the oxygen-containing gas inlets;
the reaction system comprises a reactor, the discharge end of the waste alkali liquor conveying pipeline is connected with a reaction raw material inlet at the bottom of the reactor, a reaction product outlet pipeline is arranged at the top of the reactor, and the discharge end of the reaction product outlet pipeline is connected with a product separation system;
the heat-conducting medium heat exchange system comprises a heat-conducting medium circulating pipeline, the heat-conducting medium circulating pipeline is connected with a reaction product outlet pipeline through a heat-conducting medium/reaction product heat exchanger, and the heat-conducting medium circulating pipeline is connected with a waste alkali liquor conveying pipeline through a heat-conducting medium/feeding heat exchanger;
the oxygen-containing gas inlets are located upstream of the heat transfer medium/feed heat exchanger, downstream of the heat transfer medium/feed heat exchanger, and optionally on the heat transfer medium/feed heat exchanger.
The oxygen-containing gas supply system of the invention provides oxygen required for oxidation reaction, the oxygen-containing gas conveying pipeline is provided with a pressure boosting device for boosting the pressure of the oxygen-containing gas, and the pressure boosting device can adopt a conventional gas compressor, such as a centrifugal compressor, a reciprocating compressor, an axial flow compressor and the like, as long as relevant process parameters are met.
According to the invention, the feed end of the waste alkali liquor conveying pipeline is connected with the waste alkali liquor tank, the waste alkali liquor conveying pipeline is provided with a feed pump, the feed pump provides required pressure for reaction, and the feed pump can adopt a conventional pump, preferably a centrifugal pump.
In the invention, in order to enable the reaction raw materials to react at a preset temperature, in the initial stage of the reaction, the temperature is low and the oxidation effect is poor, so the reaction system further comprises a steam feeding system, a steam conveying pipeline of the steam feeding system is connected with a steam inlet at the bottom of the reactor, and the steam feeding system provides necessary heat for the oxidation reaction. The reactor is provided with a temperature detection point, and the feeding amount of the steam and the temperature of the reactor form a control loop. Through additionally feeding steam, not only can the heat required in the start-up stage be provided, but also the normal operation of the oxidation reaction can be maintained when the reaction raw materials contain fewer components to be oxidized and the heat exchange effect of the heat-conducting medium/feeding heat exchanger is poor. The heating steam may be selected from saturated steam, superheated steam, preferably saturated steam, and when the reactor pressure is 3.0MPa, saturated steam having a pressure of 3.5MPa may be selected.
In order to reduce the scaling risk of the charging and discharging heat exchanger and simultaneously reduce the investment of equipment and pipelines, at least two oxygen-containing gas inlets are arranged on the waste alkali liquor conveying pipeline, and the oxygen-containing gas can enter the waste alkali liquor conveying pipeline through at least two strands and is mixed with the waste alkali liquor.
According to a specific embodiment of the present invention, the oxygen-containing gas inlet is provided in two, and the two oxygen-containing gas inlets are provided upstream and downstream of the heat transfer medium/feed heat exchanger, respectively.
According to another embodiment of the invention, the oxygen-containing gas inlet is provided with three, two are provided upstream and downstream of the heat transfer medium/feed heat exchanger, and the other is provided on the heat transfer medium/feed heat exchanger, and the heat transfer medium/feed heat exchanger is provided with a plurality of injection points.
According to the composition of the reaction raw materials, oxygen-containing gas enters the waste alkali liquor conveying pipeline through different oxygen-containing gas inlets, such as: when the butter content and the olefin content of the reaction raw materials are high, the oxygen-containing gas can be injected from the oxygen-containing gas inlet in front of the heat-conducting medium/feeding heat exchanger and/or the oxygen-containing gas inlet on the heat-conducting medium/feeding heat exchanger, so that the scaling of the heat exchanger is avoided.
According to a specific embodiment of the present invention, the oxygen-containing gas supply line is connected to the heat transfer medium circulation line via a gas/heat transfer medium heat exchanger, and the heat transfer medium outlet of the heat transfer medium/feed heat exchanger is connected to the heat transfer medium inlet of the gas/heat transfer medium heat exchanger.
According to the invention, one or two oxygen-containing gas conveying pipelines are provided, two oxygen-containing gas conveying pipelines are respectively connected with different oxygen-containing gas inlets, and the oxygen content and the pressure of the oxygen-containing gas conveyed by the two oxygen-containing gas conveying pipelines are respectively the same or different. The two oxygen-containing gas transfer lines may be fed simultaneously or one of them may be fed.
In the invention, a heat-conducting medium circulating pump and an optional heat-conducting medium buffer tank are arranged on the heat-conducting medium circulating pipeline; and the heat-conducting medium outlet of the heat-conducting medium/reaction product heat exchanger is connected with the heat-conducting medium inlet of the heat-conducting medium/feeding heat exchanger. The invention does not make any provisions on the form of the heat-conducting medium circulating pump, and a centrifugal pump, an axial flow pump or a diaphragm pump can be selected as long as the heat-conducting medium conveying requirement can be met.
In order to improve the conversion efficiency of the oxidation reaction, the reactor of the present invention may be selected from at least one of an internal loop reactor, an empty bucket + sparger reactor, a stirred reactor and a tubular reactor. From the aspects of investment, land occupation and operation, the invention preferably selects an internal circulation reactor, an empty barrel plus distributor reactor and a tubular reactor. The empty barrel and distributor reactor is characterized in that a gas-liquid distributor is arranged at the bottom of the reactor, the gas-liquid distributor can be a traditional gas-liquid distributor or a distributor capable of generating micro bubbles, and the reactor is not limited by the invention as long as gas-liquid uniform distribution is met. Internal loop reactors, empty barrel + sparger reactors, tubular reactors are well known to those skilled in the art and the present invention will not be described in detail herein.
In order to improve the heat exchange efficiency and meet the characteristics of an oxidation reaction system, the heat-conducting medium/reaction product heat exchanger, the heat-conducting medium/feed heat exchanger and the gas/heat-conducting medium heat exchanger can be respectively selected from at least one of a double-pipe heat exchanger, a U-pipe heat exchanger, a floating head heat exchanger, a fixed-pipe plate heat exchanger and a plate heat exchanger. Preferably, a double pipe heat exchanger, a U-shaped pipe heat exchanger, or a floating head heat exchanger, and in order to improve heat exchange efficiency, a multi-pipe heat exchanger may be used. Three heat exchangers, a double pipe heat exchanger, a U-tube heat exchanger and a floating head heat exchanger, are well known to those skilled in the art, and the present invention will not be described herein.
Preferably, the product separation system comprises a flash tank, a water cooler and a pressure reducing valve, wherein the discharge end of the reaction product outlet pipeline is connected with the feed inlet of the flash tank through the pressure reducing valve, the top of the flash tank is provided with a gas-phase product outlet pipeline, the bottom of the flash tank is provided with a liquid-phase product outlet pipeline, and the water cooler is arranged on the liquid-phase product outlet pipeline.
According to a second aspect of the present invention, there is provided a spent caustic wet oxidation method using the above-described spent caustic wet oxidation system, the spent caustic wet oxidation method comprising the steps of:
a) the pressure of the oxygen-containing gas is increased to obtain compressed gas, and the pressure of the waste alkali liquor is increased to obtain pressure-increased waste alkali liquor;
b) the compressed gas is mixed with the boosted waste alkali liquor through at least two oxygen-containing gas inlets on a waste alkali liquor conveying pipeline, meanwhile, the materials are subjected to heat exchange and temperature rise with the heated heat-conducting medium through a heat-conducting medium/feeding heat exchanger to obtain reaction raw materials, and the reaction raw materials are fed into a reactor for oxidation reaction;
c) and pumping the heat-conducting medium to become the heat-conducting medium after temperature rise, and circulating the heat-conducting medium to a heat-conducting medium/feeding heat exchanger to exchange heat with the reaction raw material.
According to the invention, in order to control the temperature of the tube wall of the heat exchange tube at the feeding side of the reaction raw material, a heat conducting medium system is adopted, the reaction product and the reaction raw material transfer heat through the heat conducting medium system, the heat conducting medium in the heat conducting medium circulating pipeline is the same medium in circulation, and the heat conducting medium has the same composition regardless of temperature rise and temperature reduction, and can be at least one selected from deoxygenated water, desalted water, heat conducting oil and molten salt, and preferably at least one of the deoxygenated water, the desalted water and the heat conducting oil.
In the invention, the waste alkali liquor contains at least one of sulfur-containing compounds, phenolic compounds, benzene and benzene compounds, ketone compounds, ester compounds, nitrogen-containing compounds and free oil. The waste alkali liquor can be oil refining alkaline residue, ethylene alkaline residue, and ethylene and oil refining mixed alkaline residue.
According to the invention, the volume fraction of oxygen in the oxygen-containing gas is not less than 10%. The oxygen-containing gas may be air, pure oxygen, oxygen-enriched gas. The oxygen content and pressure of the oxygen-containing gas delivered by the different oxygen-containing gas delivery lines may be different.
Because the oxidation reaction is a strong exothermic reaction, the outlet temperature of the reaction product is above 150 ℃. After the reaction product exchanges heat with the heat-conducting medium, the heat-conducting medium can preheat the reaction raw material, in addition, in order to improve the energy utilization efficiency, the heat-conducting medium can also exchange heat with the oxygen-containing gas, the feeding temperature of the oxygen-containing gas is increased, the preheated oxygen-containing gas is mixed with the waste alkali liquor, namely, the compressed gas is mixed with the pressure-boosting waste alkali liquor after being subjected to heat exchange with the heat-conducting medium after being subjected to heat exchange with the reaction product.
In the invention, the temperature of the oxidation reaction can be 150-250 ℃, and preferably 180-220 ℃; the reaction pressure may be 2.5MPaG to 5.5MPaG, preferably 2.8MPaG to 3.5 MPaG.
The reaction product is cooled by a heat-conducting medium/reaction product heat exchanger, is decompressed by a decompression valve and then enters a flash tank for gas-liquid separation, and a gas-phase product (unreacted oxygen, non-condensable gas and the like) is obtained at the top of the flash tank, can be directly sent to a torch system for treatment or directly discharged at a high point, and is preferably sent to the torch system; and cooling the liquid-phase product obtained at the bottom of the tank by a water cooler to obtain a completely oxidized cooled liquid-phase product, and further conveying the liquid-phase product to a downstream sewage treatment device. The pressure of the flash tank can be selected according to the back pressure of the flare system, the back pressure value of the flare system is generally not less than 0.1MPa, and the pressure of the flash tank can be selected to be 0.15MPaG to 0.55MPaG, preferably 0.25MPaG to 0.4 MPaG.
The process parameters which are not limited in the invention can be selected conventionally according to the prior art.
The present invention will be described in detail by way of examples.
Examples 1-7 illustrate the spent caustic wet oxidation system and method of the present invention.
Example 1
As shown in fig. 1, a spent caustic wet oxidation system comprises a reaction raw material feeding system, a reaction system, a heat transfer medium heat exchange system and a product separation system;
the reaction raw material feeding system comprises an oxygen-containing gas supply system and a waste alkali liquor supply system, the oxygen-containing gas supply system comprises an oxygen-containing gas conveying pipeline, the waste alkali liquor supply system comprises a waste alkali liquor conveying pipeline, two oxygen-containing gas inlets are formed in the waste alkali liquor conveying pipeline, and the oxygen-containing gas conveying pipeline is connected with the oxygen-containing gas inlets;
the reaction system comprises a reactor 102, the discharge end of the waste alkali liquor conveying pipeline is connected with a reaction raw material inlet at the bottom of the reactor 102, the top of the reactor 102 is provided with a reaction product outlet pipeline, and the discharge end of the reaction product outlet pipeline is connected with a product separation system;
the heat-conducting medium heat exchange system comprises a heat-conducting medium circulation pipeline, the heat-conducting medium circulation pipeline is connected with a reaction product outlet pipeline through a heat-conducting medium/reaction product heat exchanger 109, the heat-conducting medium circulation pipeline is connected with a waste alkali liquor conveying pipeline through a heat-conducting medium/feeding heat exchanger 105, and two oxygen-containing gas inlets are respectively arranged at the upstream and the downstream of the heat-conducting medium/feeding heat exchanger 105.
The oxygen-containing gas delivery line is provided with a gas compressor 101.
The feed end of the waste alkali liquor conveying pipeline is connected with a waste alkali liquor tank 103, and a feed pump 104 is arranged on the waste alkali liquor conveying pipeline.
The reaction system further comprises a steam feeding system, and a steam conveying pipeline of the steam feeding system is connected with a steam inlet at the bottom of the reactor 102; the reactor 102 is provided with a temperature detection point, and the feeding amount of the steam 12 and the temperature of the reactor 102 form a control loop.
The heat-conducting medium circulation pipeline is provided with a heat-conducting medium circulation pump 111 and a heat-conducting medium buffer tank 110.
The heat transfer medium outlet of the heat transfer medium/reaction product heat exchanger 109 is connected to the heat transfer medium inlet of the heat transfer medium/feed heat exchanger 105.
The reactor 102 is an inner loop reactor, the inner diameter of the inner loop reactor is 1500mm, and the tangent height is 12000 mm. The internal loop reactor comprises an internal loop barrel 302 and a sparger 301.
The heat-conducting medium/reaction product heat exchanger and the heat-conducting medium/feeding heat exchanger adopt floating head heat exchangers, the reaction product and the reaction raw material pass through a tube pass, and the heat-conducting medium passes through a shell pass.
The product separation system comprises a flash tank 106, a water cooler 107 and a pressure reducing valve, wherein the discharge end of the reaction product outlet pipeline is connected with the feed inlet of the flash tank 106 through the pressure reducing valve, the top of the flash tank 106 is provided with a gas-phase product outlet pipeline, the bottom of the flash tank 106 is provided with a liquid-phase product outlet pipeline, and the water cooler 107 is arranged on the liquid-phase product outlet pipeline.
The waste alkali wet oxidation method adopting the waste alkali wet oxidation system comprises the following steps:
a) the pressure of the oxygen-containing gas 1 is increased to obtain compressed gas 2, and the pressure of the waste alkali liquor 4 is increased to obtain pressure-increased waste alkali liquor 5;
b) the compressed gas 2 is divided into two streams and is mixed with the boosting waste alkali liquor 5 through two oxygen-containing gas inlets on a waste alkali liquor conveying pipeline, the first stream of compressed gas 3a is mixed with the boosting waste alkali liquor 5 to obtain low-oxygen-containing waste alkali liquor 14, the low-oxygen-containing waste alkali liquor 14 exchanges heat with the heated heat-conducting medium 21 through the heat-conducting medium/feeding heat exchanger 105 to obtain heat-exchanged low-oxygen-containing waste alkali liquor 6, the heat-exchanged low-oxygen-containing waste alkali liquor 21 becomes a cooled heat-conducting medium 22 after being heated, the second stream of compressed gas 3b is mixed with the heat-exchanged low-oxygen-containing waste alkali liquor 6 to obtain high-oxygen-containing waste alkali liquor 15, and the high-oxygen-containing waste alkali liquor 15 is conveyed to the reactor 102 for oxidation reaction;
c) the reaction product 7 obtained by the oxidation reaction enters a reaction product outlet pipeline from the top of the reactor 102, the reaction product 7 is cooled by pumping a heat-conducting medium 20 to obtain a cooled reaction product 8, the heat-conducting medium 20 is pumped to become a heated heat-conducting medium 21, the heated heat-conducting medium 21 is circulated to a heat-conducting medium/feeding heat exchanger 105 to exchange heat with the reaction raw material, the cooled reaction product 8 is depressurized by a pressure reducing valve and then sent to a flash tank 106 to be subjected to gas-liquid separation to obtain a gas-phase product 11 and a liquid-phase product 9, and the liquid-phase product 9 is cooled by a water cooler 107 (the cooling medium is cooling water 13) to obtain a cooled liquid-phase product 10.
The waste alkali liquor is ethylene waste alkali liquor, and the composition of the ethylene waste alkali liquor is shown in table 1.
TABLE 1
| Parameters of ethylene spent lye | Numerical value |
| NaOH，wt％ | 1.4 |
| Sodium carbonate, wt% | 5.75 |
| Sodium sulfide, wt% | 3.8 |
| Benzene, mg/L | 372 |
| Phenol, mg/L | 35 |
| COD，mg/L | 25000 |
| Free oil, mg/L | 1020 |
| TOC，mg/L | ～4100 |
| TSS，mg/L | ～1400 |
| Temperature, C | ～40 |
| Pressure, MPaG | 0.50 |
The ethylene waste alkali liquor to be oxidized mainly comprises the following substances: sodium sulfide, phenol, COD, free oil, etc. The heat-conducting medium is deoxygenated water, the flow rate is 45t/h, the heat-conducting medium circulating pump 111 adopts a centrifugal pump, the pressure at the pump inlet is 0.5MPa, the pressure at the pump outlet is 0.85MPa, the temperature of the heat-conducting medium to be pumped is 110 ℃, the temperature of the heat-conducting medium after temperature rise is 150 ℃, and the temperature of the heat-conducting medium after temperature drop is 110 ℃.
The temperature of the oxidation reaction was 200 ℃ and the reaction pressure was 3.2 MPaG. The flash tank 106 pressure is 0.35 MPaG. The feed pump 104 is selected from a centrifugal pump with an outlet pressure of 3.6MPaG and a flow rate of 25 t/h; the oxygen-containing gas is air and the gas compressor 101 is selected from reciprocating compressors having an outlet pressure of 3.7MPaG and a flow rate of 3500Nm3H; the first stream of compressed gas 3a is injected in an amount of 500Nm3H, the second compressed gas 3b is injected in an amount of 3000Nm3H is used as the reference value. The present embodiment does not require steam 12 for normal reaction.
The compositions of the treated alkali liquor (liquid phase product) and the treated tail gas (gas phase product) obtained by sequentially carrying out oxidation reaction, heat exchange and reduced pressure separation on the ethylene waste alkali liquor are shown in tables 2 and 3.
TABLE 2
| Parameters of the treated lye | Numerical value |
| Pressure, MPaG | 0.3 |
| Temperature, C | 45 |
| S2-，mg/L | 0.5 |
| COD，mg/L | 3000 |
| Phenol, mg/L | 24 |
| Oil, mg/L | 38 |
| Benzene, mg/L | 16 |
TABLE 3
As can be seen from tables 1 to 3, sodium sulfide, phenol, COD, free oil, etc. were substantially oxidized, and the removal rates of sodium sulfide, phenol, COD, free oil, etc. were: 99.99 percent, 29.4 percent, 88.89 percent and 96.38 percent, and the treated alkali liquor meets the water inlet requirement of a downstream sewage treatment plant. The reaction heat generated in this example, in addition to preheating the feed, requires additional cooling using a water cooler.
Example 2
As shown in fig. 2, the spent caustic wet oxidation system of this example is the same as that of example 1 except that the reactor 102 is in the form of an empty tank + distributor 301, compared to example 1.
The waste lye of the present example is also ethylene waste lye, the composition and flow of which are the same as those of example 1, except that: the reaction temperature of the reactor 102 was 190 ℃, the reaction pressure was 3.35MPaG, and the outlet pressure of the feed pump 104 was 3.75 MPaG; the gas compressor 101 outlet pressure was 3.9 MPaG. The rest process parameters and equipment models are the same as those of the embodiment 1, and the embodiment does not need to supplement steam during normal reaction.
In the embodiment, demineralized water is adopted as a heat-conducting medium, the flow rate is 42t/h, a centrifugal pump is adopted as the heat-conducting medium circulating pump 111, the pressure at the inlet of the pump is 0.5MPa, the pressure at the outlet of the pump is 0.85MPa, the temperature of the heat-conducting medium 20 pumped is 115 ℃, the temperature of the heat-conducting medium 21 after temperature rise is 155 ℃, and the temperature of the heat-conducting medium 22 after temperature reduction is 115 ℃.
Analysis shows that substances such as sodium sulfide, phenol, COD and free oil are basically oxidized, and the removal rates of the sodium sulfide, the phenol, the COD and the free oil are respectively as follows: 99.99 percent, 28.1 percent, 85.32 percent and 94.91 percent, and the treated alkali liquor meets the water inlet requirement of a downstream sewage treatment plant.
Example 3
As shown in fig. 3, the spent caustic wet oxidation system of this example is the same as that of example 1 except that the reactor 102 is in the form of a tubular reactor, compared to example 1. The tubular reactor had an internal diameter of 200mm and a length of 130000 mm.
The waste alkali liquor of the example is oil refining waste alkali liquor, the treatment capacity of the waste alkali liquor is 7t/h, and the air feeding quantity is 1100Nm3H is used as the reference value. The composition of the spent lye is shown in Table 4.
TABLE 4
| Parameters of oil refining waste alkali liquor | Numerical value |
| pH | 13.1 |
| COD，mg/L | 43200 |
| Density, g/cm3 | 1.06 |
| TDS，mg/L | 5120 |
| B/C | 0.26 |
| Free oil, mg/L | 370 |
| Phenol, mg/L | 175 |
| Benzene, mg/L | 60 |
| Ethylbenzene, mg/L | 220 |
| Toluene, mg/L | 68 |
| SS，mg/L | 210 |
| Ketones, mg/L | 45 |
| Esters, mg/L | 632 |
| Sulfur-containing compound (wt)% | 1.49 |
| TN，mg/L | 133 |
| Methyldiethanolamine wt% | 1.2 |
The reaction temperature of the reactor 102 of this example was 180 ℃, the reaction pressure was 3.3MPaG, and the outlet pressure of the feed pump 104 was 3.55 MPaG; the gas compressor 101 outlet pressure was 3.6 MPaG. The first stream of compressed gas 3a is injected in an amount of 300Nm3H, the second compressed gas 3b is injected in an amount of 800Nm3H is used as the reference value. When the reaction temperature is lower than 180 ℃ due to the feed fluctuation, a valve on a steam feed line is opened to supplement heat to the reactor 102, and saturated steam of 3.5MPa is used as the steam until the temperature reaches 180 ℃. In addition, when the composition of the reaction raw materials is changed, the flow rates of the two compressed gases can be adjusted. For example, when the content of free oil in the feed is increased, the injection amount of the first compressed gas 3a is increased, so that the risk of scaling and blockage in the heat exchanger can be reduced, and the air injection amount is reduced.
In the embodiment, demineralized water is adopted as a heat-conducting medium, the flow rate is 50t/h, a centrifugal pump is adopted as the heat-conducting medium circulating pump 111, the pressure at the inlet of the pump is 0.5MPa, the pressure at the outlet of the pump is 0.85MPa, the temperature of the heat-conducting medium 20 pumped is 105 ℃, the temperature of the heat-conducting medium 21 after temperature rise is 140 ℃, and the temperature of the heat-conducting medium 22 after temperature drop is 105 ℃.
Analysis shows that substances such as sulfur-containing compounds, phenol, COD, free oil and the like are basically oxidized, and the removal rates of sodium sulfide, phenol, COD and free oil are respectively as follows: 100%, 20.5%, 88.91% and 90.61%, wherein the treated alkali liquor meets the water inlet requirement of a downstream sewage treatment plant.
Example 4
As shown in fig. 4, the present embodiment providesCompared with the wet oxidation system of the waste alkali in the embodiment 2, two oxygen-containing gas conveying pipelines are arranged, one oxygen-containing gas conveying pipeline conveys a first flow of compressed gas 3a, the first flow of compressed gas 3a is air, and the flow rate is 500Nm3The other is a second compressed gas 3b which is delivered, the second compressed gas 3b being pure oxygen and injected in an amount of 550Nm3The injection pressure was 3.8 MPaG.
The waste lye of the present example is also ethylene waste lye, the composition and flow of which are the same as in example 2, the inner diameter of the reactor is 1300mm, and the tangential height is 9000 mm. The rest process parameters and equipment models are the same as those of the embodiment 2, and the embodiment does not need to supplement steam during normal reaction. As the second compressed gas 3b is pure oxygen, the size of the reactor is greatly reduced compared with that of the reactor in the embodiment 2, the occupied area is reduced, and the equipment investment is saved.
In the embodiment, heat conduction oil is used as a heat conduction medium, the flow rate is 35t/h, a centrifugal pump is used as the heat conduction medium circulating pump 111, the pressure at the inlet of the pump is 0.5MPa, the pressure at the outlet of the pump is 0.85MPa, the temperature of the heat conduction medium pumped is 110 ℃, the temperature of the heat conduction medium heated is 160 ℃, and the temperature of the heat conduction medium cooled is 22 ℃.
Analysis shows that substances such as sodium sulfide, phenol, COD and free oil are basically oxidized, and the removal rates of the sodium sulfide, the phenol, the COD and the free oil are respectively as follows: 100 percent, 39.15 percent, 90.15 percent and 96.82 percent, and the treated alkali liquor meets the water inlet requirement of a downstream sewage treatment plant.
Example 5
As shown in fig. 5, the wet oxidation system for spent caustic provided in this embodiment is added with a gas/heat transfer medium heat exchanger 108 compared to embodiment 2, the oxygen-containing gas delivery line is connected to the heat transfer medium circulation line via the gas/heat transfer medium heat exchanger 108, and the heat transfer medium outlet of the heat transfer medium/feed heat exchanger 105 is connected to the heat transfer medium inlet of the gas/heat transfer medium heat exchanger 108. The investment of equipment is slightly increased in the initial period, and a part of the occupied area is increased. Compressed gas 2 in this embodiment exchanges heat with heat-conducting medium 22 after cooling down earlier, the gaseous 3 branch of getting intensification injects the feeding into by two, after this embodiment increases gas/heat-conducting medium heat exchanger 108, not only can reduce heat-conducting medium pump inlet temperature, increase the heat transfer difference in temperature of heat-conducting medium and reaction product, reduce the use amount of heat-conducting medium, can also improve the energy utilization efficiency of whole flow, on the basis of same treatment scale, same equipment size, same oxidation effect, can reduce heat-conducting medium use amount more than 20%. In the long term, the method is beneficial to energy conservation and consumption reduction, and is beneficial to improving the technical economy of the device.
In the embodiment, deoxygenated water is used as a heat-conducting medium, the flow rate is 40t/h, a centrifugal pump is used as the heat-conducting medium circulating pump 111, the pressure at the inlet of the pump is 0.6MPa, the pressure at the outlet of the pump is 0.9MPa, the temperature of the heat-conducting medium 20 to be pumped is 118 ℃, the temperature of the heat-conducting medium 21 after temperature rise is 155 ℃, and the temperature of the heat-conducting medium 22 after temperature drop is 118 ℃.
Analysis shows that substances such as sodium sulfide, phenol, COD and free oil are basically oxidized, and the removal rates of the sodium sulfide, the phenol, the COD and the free oil are respectively as follows: 99.99 percent, 32.35 percent, 86.43 percent and 95.71 percent, and the treated alkali liquor meets the water inlet requirement of a downstream sewage treatment plant.
Example 6
As shown in fig. 6, in the wet oxidation system of spent caustic soda provided in this embodiment, compared with embodiment 5, there are three oxygen-containing gas inlets, two inlets are respectively disposed upstream and downstream of the heat transfer medium/feed heat exchanger 105, and the other inlet is disposed on the heat transfer medium/feed heat exchanger 105. The compressed gas 2 exchanges heat with the cooled heat-conducting medium 22, the obtained heated gas 3 is divided into three streams and then injected into the feeding material, and the added stream is the third stream of compressed gas 3c which is directly injected into the heat-conducting medium/feeding heat exchanger 105 and is mixed with the reaction raw material during heat exchange. In the heat exchanger with a double pipe used in the heat conducting medium/feeding heat exchanger 105 of this embodiment, the size of the outer pipe is 150mm, the size of the inner pipe is 100mm, and the length of the heat exchanger is 180000mm, as shown in fig. 8, a plurality of injection points are arranged on the heat conducting medium/feeding heat exchanger 105. The oxygen-containing gas used in this example was air. The air flow rate at the outlet of the air compressor was the same as that in example 5, which was applied to the oxidation of ethylene spent lye, and the properties thereof are shown in Table 5.
TABLE 5
| Parameters of ethylene spent lye | Numerical value |
| NaOH，wt％ | 1.2 |
| Sodium carbonate, wt% | 5.8 |
| Sodium sulfide, wt% | 3.6 |
| Benzene, mg/L | 340 |
| Phenol, mg/L | 30 |
| COD，mg/L | 29000 |
| Free oil, mg/L | 2450 |
| TOC，mg/L | ～6000 |
| TSS，mg/L | ～1600 |
| Temperature, C | ～42 |
| Pressure, MPaG | 0.50 |
As can be seen from Table 5, the free oil and COD contents are high, and in order to avoid coking and scaling in the charging and discharging heat exchanger and influence the heat exchange effect, air is injected from a proper position in the heat-conducting medium/charging heat exchanger 105, and the distance between adjacent air injection points is 5000 mm. The first compressed gas 3a is injected in an amount of 200Nm3Per injection point injection rate of 10Nm in the heat transfer medium/feed heat exchanger 1053H, the second compressed gas 3b is injected in an amount of 2930Nm3/h。
In the embodiment, deoxygenated water is used as a heat-conducting medium, the flow rate is 42t/h, a centrifugal pump is used as the heat-conducting medium circulating pump 111, the pressure at the inlet of the pump is 0.6MPa, the pressure at the outlet of the pump is 0.88MPa, the temperature of the heat-conducting medium 20 to be pumped is 115 ℃, the temperature of the heat-conducting medium 21 after temperature rise is 165 ℃, and the temperature of the heat-conducting medium 22 after temperature decrease is 115 ℃.
Analysis shows that substances such as sodium sulfide, phenol, COD and free oil are basically oxidized, and the removal rates of the sodium sulfide, the phenol, the COD and the free oil are respectively as follows: 99.99 percent, 26.35 percent, 87.34 percent and 94.81 percent, and the treated alkali liquor meets the water inlet requirement of a downstream sewage treatment plant.
Example 7
As shown in fig. 7, the system for wet oxidation of spent caustic soda provided in this embodiment is the same as that of embodiment 1 except that there is no buffer tank 110 for heat transfer medium, as compared with embodiment 1. The same procedure as in example 1 was repeated except that the temperature of the oxidation reactor was 190 ℃, the reaction pressure was 3.4MPaG, and the outlet pressure of the feed pump 104 was 3.8 MPaG; the gas compressor 101 outlet pressure was 3.92 MPaG. The rest process parameters and equipment models are the same as those of the embodiment 1, and the embodiment does not need to supplement steam during normal reaction.
In the embodiment, deoxygenated water is used as a heat-conducting medium, the flow rate is 46t/h, a centrifugal pump is used as the heat-conducting medium circulating pump 111, the pressure at the inlet of the pump is 0.52MPa, the pressure at the outlet of the pump is 0.88MPa, the temperature of the heat-conducting medium pumped is 110 ℃, the temperature of the heat-conducting medium heated 21 is 160 ℃, and the temperature of the heat-conducting medium cooled 22 is 110 ℃.
Analysis shows that substances such as sodium sulfide, phenol, COD and free oil are basically oxidized, and the removal rates of the sodium sulfide, the phenol, the COD and the free oil are respectively as follows: 99.98 percent, 28.4 percent, 84.81 percent and 95.14 percent, and the treated alkali liquor meets the water inlet requirement of a downstream sewage treatment plant.
The wet oxidation system and the wet oxidation method for the waste alkali, which are provided by the invention, have the advantages of large treatment capacity, flexible operation, strong applicability, good oxidation effect, adjustable pipe wall temperature of a heat-conducting medium/feeding heat exchanger, no blockage of pipelines and equipment, stable operation of the device, low energy consumption and operation cost and the like.
Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the illustrated embodiments.
Claims (10)
1. The wet oxidation system for the waste alkali is characterized by comprising a reaction raw material feeding system, a reaction system, a heat-conducting medium heat exchange system and a product separation system;
the reaction raw material feeding system comprises an oxygen-containing gas supply system and a waste alkali liquor supply system, the oxygen-containing gas supply system comprises at least one oxygen-containing gas conveying pipeline, the waste alkali liquor supply system comprises a waste alkali liquor conveying pipeline, at least two oxygen-containing gas inlets are formed in the waste alkali liquor conveying pipeline, and the oxygen-containing gas conveying pipeline is connected with the oxygen-containing gas inlets;
the reaction system comprises a reactor, the discharge end of the waste alkali liquor conveying pipeline is connected with a reaction raw material inlet at the bottom of the reactor, a reaction product outlet pipeline is arranged at the top of the reactor, and the discharge end of the reaction product outlet pipeline is connected with a product separation system;
the heat-conducting medium heat exchange system comprises a heat-conducting medium circulating pipeline, the heat-conducting medium circulating pipeline is connected with a reaction product outlet pipeline through a heat-conducting medium/reaction product heat exchanger, and the heat-conducting medium circulating pipeline is connected with a waste alkali liquor conveying pipeline through a heat-conducting medium/feeding heat exchanger;
the oxygen-containing gas inlets are located upstream of the heat transfer medium/feed heat exchanger, downstream of the heat transfer medium/feed heat exchanger, and optionally on the heat transfer medium/feed heat exchanger.
2. The spent caustic wet oxidation system of claim 1, wherein a gas compressor is provided on the oxygen containing gas transfer line;
the feeding end of the waste alkali liquor conveying pipeline is connected with a waste alkali liquor tank, and a feeding pump is arranged on the waste alkali liquor conveying pipeline;
the reaction system also comprises a steam feeding system, and a steam conveying pipeline of the steam feeding system is connected with a steam inlet at the bottom of the reactor; the reactor is provided with a temperature detection point, and the feeding amount of the steam and the temperature of the reactor form a control loop.
3. The spent caustic wet oxidation system of claim 1, wherein there are two oxygen-containing gas inlets, the two oxygen-containing gas inlets being located upstream and downstream of the heat transfer medium/feed heat exchanger, respectively;
or the oxygen-containing gas inlets are three, two of the oxygen-containing gas inlets are respectively arranged at the upstream and the downstream of the heat-conducting medium/feeding heat exchanger, the other one is arranged on the heat-conducting medium/feeding heat exchanger, and a plurality of injection points are arranged on the heat-conducting medium/feeding heat exchanger.
4. The spent caustic wet oxidation system of any one of claims 1 to 3, wherein the oxygen-containing gas transfer line is connected to the heat transfer medium circulation line via a gas/heat transfer medium heat exchanger and the heat transfer medium outlet of the heat transfer medium/feed heat exchanger is connected to the heat transfer medium inlet of the gas/heat transfer medium heat exchanger;
the oxygen-containing gas conveying pipelines are provided with one or two, the two oxygen-containing gas conveying pipelines are respectively connected with different oxygen-containing gas inlets, and the oxygen content and the pressure of the oxygen-containing gas conveyed by the two oxygen-containing gas conveying pipelines are respectively the same or different.
5. The spent caustic wet oxidation system of claim 1, wherein a heat transfer medium circulation pump and optionally a heat transfer medium buffer tank are provided on the heat transfer medium circulation line;
and the heat-conducting medium outlet of the heat-conducting medium/reaction product heat exchanger is connected with the heat-conducting medium inlet of the heat-conducting medium/feeding heat exchanger.
6. The spent caustic wet oxidation system of claim 1 or 5, wherein the reactor is selected from at least one of an internal loop reactor, an empty bucket + sparger reactor, a stirred reactor and a tubular reactor;
the heat-conducting medium/reaction product heat exchanger, the heat-conducting medium/feed heat exchanger and the gas/heat-conducting medium heat exchanger are respectively selected from at least one of a double-pipe heat exchanger, a U-shaped pipe heat exchanger, a floating head heat exchanger, a fixed pipe plate heat exchanger and a plate heat exchanger.
7. A spent caustic wet oxidation system according to claim 1 wherein the product separation system comprises a flash tank, a water cooler and a pressure reducing valve, the discharge end of the reaction product outlet line is connected to the feed inlet of the flash tank via the pressure reducing valve, the flash tank is provided with a gas phase product outlet line at the top and a liquid phase product outlet line at the bottom, and the water cooler is provided on the liquid phase product outlet line.
8. A spent caustic wet oxidation method using the spent caustic wet oxidation system of any one of claims 1 to 7, wherein the spent caustic wet oxidation method comprises the steps of:
a) the pressure of the oxygen-containing gas is increased to obtain compressed gas, and the pressure of the waste alkali liquor is increased to obtain pressure-increased waste alkali liquor;
b) the compressed gas is mixed with the boosted waste alkali liquor through at least two oxygen-containing gas inlets on a waste alkali liquor conveying pipeline, meanwhile, the materials are subjected to heat exchange and temperature rise with the heated heat-conducting medium through a heat-conducting medium/feeding heat exchanger to obtain reaction raw materials, and the reaction raw materials are fed into a reactor for oxidation reaction;
c) and pumping the heat-conducting medium to become the heat-conducting medium after temperature rise, and circulating the heat-conducting medium to a heat-conducting medium/feeding heat exchanger to exchange heat with the reaction raw material.
9. A spent caustic wet oxidation process according to claim 8, wherein the heat transfer medium is selected from at least one of oxygen-depleted water, demineralized water, heat transfer oil and molten salt;
the waste alkali liquor contains at least one of sulfur-containing compounds, phenolic compounds, benzene and benzene compounds, ketone compounds, ester compounds, nitrogen-containing compounds and free oil;
the volume fraction of oxygen in the oxygen-containing gas is not less than 10%.
10. The wet oxidation method of spent caustic according to claim 8, wherein the compressed gas is mixed with the pressurized spent caustic after being heated by the heated heat transfer medium after heat exchange with the material;
the temperature of the oxidation reaction is 150-250 ℃, and the reaction pressure is 2.5-5.5 MPaG.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010770185.XA CN114057277A (en) | 2020-08-03 | 2020-08-03 | Waste alkali wet oxidation system and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010770185.XA CN114057277A (en) | 2020-08-03 | 2020-08-03 | Waste alkali wet oxidation system and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114057277A true CN114057277A (en) | 2022-02-18 |
Family
ID=80231692
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010770185.XA Pending CN114057277A (en) | 2020-08-03 | 2020-08-03 | Waste alkali wet oxidation system and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114057277A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114873710A (en) * | 2022-05-24 | 2022-08-09 | 陕西延长石油（集团）有限责任公司 | Device and process for treating waste alkali liquor by wet oxidation method |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5891346A (en) * | 1996-05-01 | 1999-04-06 | Stone & Webster Engineering Limited | Spent caustic system |
| US20080078724A1 (en) * | 2006-10-03 | 2008-04-03 | Siemens Water Technologies Corp. | Wet oxidation of soot |
| CN101164913A (en) * | 2006-07-04 | 2008-04-23 | 林德股份公司 | Oxidation method and equipment for spent caustic in petrochemistry equipment |
| CN102285729A (en) * | 2010-06-18 | 2011-12-21 | 中国石油化工股份有限公司 | High-temperature wet-oxidation treatment method for waste alkali liquid |
| CN103115521A (en) * | 2012-11-11 | 2013-05-22 | 安徽金禾实业股份有限公司 | Device and method for tube type heat exchanger on-line washing |
| CN106288934A (en) * | 2015-06-01 | 2017-01-04 | 中国石油天然气集团公司 | Heat exchanger On Line Foul Removing Technology method and device |
| CN107572651A (en) * | 2017-09-14 | 2018-01-12 | 同济大学 | A kind of method and device of multistage wet oxidation processing industrial wastewater |
| CN111115789A (en) * | 2018-10-30 | 2020-05-08 | 中国石油化工股份有限公司 | Method for treating refined waste water in acrylonitrile production process |
-
2020
- 2020-08-03 CN CN202010770185.XA patent/CN114057277A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5891346A (en) * | 1996-05-01 | 1999-04-06 | Stone & Webster Engineering Limited | Spent caustic system |
| CN101164913A (en) * | 2006-07-04 | 2008-04-23 | 林德股份公司 | Oxidation method and equipment for spent caustic in petrochemistry equipment |
| US20080078724A1 (en) * | 2006-10-03 | 2008-04-03 | Siemens Water Technologies Corp. | Wet oxidation of soot |
| CN102285729A (en) * | 2010-06-18 | 2011-12-21 | 中国石油化工股份有限公司 | High-temperature wet-oxidation treatment method for waste alkali liquid |
| CN103115521A (en) * | 2012-11-11 | 2013-05-22 | 安徽金禾实业股份有限公司 | Device and method for tube type heat exchanger on-line washing |
| CN106288934A (en) * | 2015-06-01 | 2017-01-04 | 中国石油天然气集团公司 | Heat exchanger On Line Foul Removing Technology method and device |
| CN107572651A (en) * | 2017-09-14 | 2018-01-12 | 同济大学 | A kind of method and device of multistage wet oxidation processing industrial wastewater |
| CN111115789A (en) * | 2018-10-30 | 2020-05-08 | 中国石油化工股份有限公司 | Method for treating refined waste water in acrylonitrile production process |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114873710A (en) * | 2022-05-24 | 2022-08-09 | 陕西延长石油（集团）有限责任公司 | Device and process for treating waste alkali liquor by wet oxidation method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9187512B2 (en) | Process for treating lignin | |
| CN102285729A (en) | High-temperature wet-oxidation treatment method for waste alkali liquid | |
| US9790641B2 (en) | Process for treating lignin | |
| CN106630526B (en) | Sludge hydro-thermal oxidation reaction system and method with product backflow pretreatment | |
| CN105001185A (en) | Maleic anhydride tail gas treatment equipment and maleic anhydride tail gas treatment process | |
| CN114408869B (en) | Sodium sulfide production system and process for gas-phase fluidization reduction of sodium sulfate | |
| CN206607136U (en) | A kind of sludge water thermal oxidative reaction system for pretreatment of being backflowed with product | |
| CN108117208A (en) | The processing method and processing unit of a kind of alkali residue waste liquid | |
| CN114057277A (en) | Waste alkali wet oxidation system and method | |
| JP7119115B2 (en) | Acrolein reactor wastewater treatment method and apparatus | |
| CN112919611B (en) | High mass transfer circulation reactor based on fractal bubbles and waste alkali liquor oxidation method | |
| CN114988552A (en) | Treatment system and method for waste alkali liquor | |
| CN111544914A (en) | Coal gasification low pressure black water flash distillation heat recovery system | |
| CN218962222U (en) | System for recycling ammonia and by-product active calcium through ammonia-calcium desulfurization | |
| CN109381887B (en) | Pretreatment system and method for high ammonia nitrogen acidic condensate of conversion unit | |
| CN114057278B (en) | Waste alkali liquid treatment device and method | |
| CN109422641B (en) | Continuous production method for preparing calcium formate from yellow phosphorus tail gas | |
| CN214936760U (en) | Residual oil catalytic thermal cracking and coal-to-olefin waste alkali liquor resource utilization device | |
| CN104058368A (en) | Process and system for producing hydrogen by converting hydrocarbon-containing tail gas | |
| CN114684953B (en) | Method and device for treating ethylene waste alkali liquor | |
| CN107758964A (en) | A kind of system and its processing method for spent lye processing | |
| CN113292191A (en) | Residual oil catalytic pyrolysis and coal-to-olefin waste alkali liquor resource utilization device | |
| CN114057276A (en) | Wet oxidation method and system | |
| CN203486931U (en) | Sewage treatment unit for production of coal chemical industry | |
| CN118221281A (en) | Wet oxidation method and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB03 | Change of inventor or designer information | ||
| CB03 | Change of inventor or designer information |
Inventor after: Song Jianjian Inventor after: Liu Tiandu Inventor after: Zhang Xu Inventor after: Jian Jianghai Inventor after: An Jinghui Inventor after: Qin Yongqiang Inventor after: Liu Sihu Inventor after: Chu Pengfei Inventor after: Zhou Zhibin Inventor before: Song Jianjian Inventor before: Liu Tiandu Inventor before: Zhang Xu Inventor before: Jian Jianghai Inventor before: An Jinghui Inventor before: Qin Yongqiang |
|
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220218 |