The supercritical water oxidation treatment system of printing and dyeing sludge and technique
[technical field]
The invention belongs to environment protection and chemical field, particularly a kind of super critical water treatment system and technique.
[background technology]
The waste water water yield of textile printing and dyeing industry is large, colourity is high, change of water quality is large, biodegradability is poor.2013, the wastewater discharge of China's textile printing and dyeing industry reached 21.5 hundred million tons, accounts for 11.2% of discharged volume of industrial waste water in the current year.Wherein dyeing waste water accounts for 80% of textile printing and dyeing industry waste water, is a kind of unmanageable organic industrial sewage.Physico-chemical process and biological treatment are mainly contained to the traditional treatment method of dyeing waste water.But the subject matter of traditional treatment method is produce secondary pollutant printing and dyeing sludge in treating processes, often process 1000 tons of dyeing waste waters by generation 10 ~ 30 tons of wet mud (water ratio 97%).And containing dyestuff, slurry, auxiliary agent etc. in printing and dyeing sludge, composition is very complicated, and wherein the structure of dyestuff has nitro and the heavy metal element such as aminocompound and copper, chromium, zinc, arsenic, has larger bio-toxicity, very strong to the pollution of environment, belong to Hazardous wastes.Printing and dyeing sludge has become the serious environmental problem of one, China.
At present, landfill method, burning method, Land_use change method, anaerobic digestion, wet oxidation process etc. are comprised to the method for disposal of printing and dyeing sludge.But it is serious that landfill method disposes printing and dyeing sludge appropriation of land, and can polluted underground water.Burning method will consume a large amount of energy, and processing cost is high, and can produce secondary pollution in process without NO
x, SO
x, dioxin etc.The composting efficiency of Land_use change method is low, and pollutent also can enter human body by food chain.The complex process of anaerobic digestion, one-time investment is large, runs difficult, finally still needs sanitary landfill.The speed of response of wet oxidation process is slow, and process thoroughly (clearance 70 ~ 90%), does not also need subsequent disposal.Therefore need to develop that a kind of technique is simple, treatment effect good, floor space is little, facility investment and working cost low, there is the printing and dyeing sludge novel treatment technique of application prospect.
Supercritical Water Oxidation Technology (SupercriticalWaterOxidation, be called for short SCWO) be utilize water at supercritical state (Tc=374 DEG C, Pc=22.1MPa) special property had under, organism and oxygenant are dissolved in supercritical water completely, and there is rapidly homogeneous oxidizing reaction, rapidly, up hill and dale organism is changed into innoxious CO
2, N
2, H
2the micromolecular compounds such as O.Compare with the treatment technology of traditional organic waste and there is obvious technical superiority: 1) reaction is thorough, processing efficiency is high; 2) reactive system is closed, and can not produce secondary pollution.3) speed of reaction is high, and organism removes that the required residence time is very short completely, and therefore the volume of reactor is little, and the floor space of whole device is few; 4) when organic content is more than 3wt%, the heat of self release in reaction process can be relied on to maintain system thermal balance, and do not need extraneous interpolation auxiliary heat, rich heat can also be recycled.SCWO technology is defined as the most promising waste treatment technique in one of the large field of six listed by American National gordian technique " energy and environment ".
At present, supercritical water oxidation treatment technology has been successfully applied in the disposal field to municipal sludge.Within 2002, ChematurEngineeringAB company of Sweden develops 168m
3the municipal sludge Supercritical water oxidation treatment device of/d.Within 2013, SuperWaterSolutions company of the U.S. builds up the municipal sludge Supercritical water oxidation treatment device that treatment capacity is about 100t/d, pollutants removal rate reaches more than 99%, and sufficient proof supercritical Water Oxidation Technology disposes the feasibility of organic sludge.
Although supercritical Water Oxidation Technology has been made significant headway, in system reliability, still there is a series of problem:
(1) by supercritical water oxidation degradable organic pollutant, will by more than material temperature-pressure to the stagnation point of water.Except organic pollutant self-heat generation in system normal course of operation can meet except reactor content preheat requirements, still need a large amount of supplies of fuel at system start-up phase.Existing supercritical water oxidation apparatus generally adopts the mode of gas furnace direct heating organism material, but it is general containing polymer hardly degraded organic substance in pollutent, the reaction of coking carbon distribution is easily there is in heat-processed, the tar produced or coke stick to pipeline wall, pipe heat-transfer can be caused to worsen, also may cause gas furnace line clogging, have a strong impact on the safe and reliable operation of gas furnace.
(2) ionic product of water and specific inductivity significantly reduce near supercritical region, make the water of super critical condition become non-polar solvent.Not only containing insoluble inert solid in mud, soluble inorganic salt solubleness in supercritical water obviously reduces in addition, and then separates out from water and exist with the form of solid particulate.These solid particulates in systems in which flowing can cause conveying pipe or equipment blocking, have a strong impact on the safety of system, reliability service.In addition, insoluble inert solid is still present in after the reaction after cooling in fluid, and when flowing through back pressure valve step-down, the whole pressure drop of system realizes at a point, and thus back pressure valve place rate of flow of fluid is very high.Inert inorganic salt now in fluid can cause serious abrasion or latch up phenomenon to back pressure valve, and then the reliability service of influential system.
Therefore, for the exploitation of the SCWO system of printing and dyeing sludge, need the coking and blocking of preheating unit unloading phase of resolution system and inert solid to the abrasion blockage problem of decompression device, and then improve reliability and the security of system.
[summary of the invention]
The object of the present invention is to provide a kind of supercritical water oxidation treatment system and technique of printing and dyeing sludge, the pre-heating stage coking faced when overcoming the design of printing and dyeing sludge supercritical water oxidation system, solid particulate block system pipeline, equipment and the insecure problem of system step-down; The present invention can realize efficient, clean, the low cost harmless treatment of printing and dyeing sludge.
For reaching above object, the present invention takes following technical scheme:
The supercritical water oxidation treatment system of printing and dyeing sludge, comprising: sludge pretreatment part, material regenerator section, hybrid reaction part;
Sludge pretreatment part comprises sludge storage pool, the outlet of sludge storage pool and spiral pump inlet communication, spiral pump outlet is connected with mud heater case side entrance, and mud heater case side outlet connects homogenizing emulsifying pump inlet, homogenizing emulsifying pump discharge and high pressure mud surge pump inlet communication;
Material regenerator section comprises methyl alcohol and starts electric heater and mud preheater III, and the import of methyl alcohol startup electric heater exports with high-pressure methanol transferpump and is connected, and the import of high-pressure methanol transferpump connects methanol solution outlet; The entrance of mud preheater III exports with mud preheater II outer tube and is connected, and the import of mud preheater II outer tube exports with mud preheater I outer tube and is connected; Mud preheater I outer tube import and high pressure mud surge pump outlet;
Hybrid reaction part comprises overcritical water oxidization reactor, the oxygen intake of overcritical water oxidization reactor exports with snubber and is connected, snubber import connects liquid oxygen gasifier outlet, the methanol solution import of overcritical water oxidization reactor is connected to the outlet that methyl alcohol starts electric heater, the mud import of overcritical water oxidization reactor and the outlet of mud preheater III; Liquid oxygen vessel provides low-temperature liquid oxygen pump to connect liquid oxygen gasifier entrance.
The present invention further improves and is: also comprise heat recovery section; Heat recovery section comprises mud well heater and low pressure softens water pump, the side-entrance of mud heater tube is communicated with mud preheater I inner tube outlet, in mud preheater I, pipe import is connected with softening water well heater inner tube outlet, in softening water well heater, pipe import is connected with mud preheater II inner tube outlet, in mud preheater II, pipe import is communicated with steam generator side outlet, and steam generator side-entrance is connected to overcritical water oxidization reactor outlet; The pump inlet of low pressure softening water exports with softening water tank and is connected, low pressure softening water pump discharge connects the import of softening water well heater outer tube, the outlet of softening water well heater outer tube is connected with vapour generator shell-side inlet, and the saturation steam of generation exports from vapour generator shell-side outlet.
The present invention further improves and is: also comprise step-down part; Decompression portion is divided and is comprised pressure regulator valve, and pressure regulator valve import connects capillary outlet, and capillary inlet is connected with mud heater tube side outlet, and pressure regulator valve outlet and line strainer inlet communication, line strainer outlet connects liquid-collecting box.
The technology for supercritical water oxidation processing of printing and dyeing sludge, comprising:
1) when system starts, methyl alcohol and softening water enter methanol solution storage tank, be mixed with the methanol aqueous solution that concentration is 15wt%, after methanol aqueous solution is forced into 28MPa by methyl alcohol transferpump, enter methyl alcohol startup electric heater and be heated to combustion initiation temperature 500 DEG C, then enter the methanol solution import of overcritical water oxidization reactor; After liquid oxygen in liquid oxygen vessel is forced into 28MPa by low-temperature liquid oxygen pump, flow through after liquid oxygen gasifier is vaporized, by entering the oxidant inlet of overcritical water oxidization reactor after snubber; Clean water in liquid-collecting box enters mud preheater I outer tube after being forced into 28MPa by high pressure mud surge pump, flow through successively afterwards mud preheater II outer tube, mud preheater III laggard enter overcritical water oxidization reactor; In overcritical water oxidization reactor, ignition after methanol solution after heating mixes with oxygenant, after burning, high-temperature product carries out preheating to reactor, until fluid temperature (F.T.) reaches temperature of reaction 550 DEG C in reactor, the inlet feed now switching high pressure mud surge pump is printing and dyeing sludge; Open the electric check valve between homogenizing emulsifying pump to mud surge pump, close the electric check valve between liquid-collecting box to mud surge pump;
2), when system is normally run, the fluid temperature (F.T.) in overcritical water oxidization reactor is warming up to after 550 DEG C, carries out material switching; Printing and dyeing sludge in sludge storage pool, by spiral pump, is heated to 75 DEG C after entering the side-entrance of mud heater case; After flowing out from mud heater case side outlet, after the homogenized process of homogenizing emulsifying pump, flow into the import of high pressure mud surge pump, mud is transported to the outer tube side-entrance of mud preheater I after being pressurized to 28MPa, is flowed out from outer tube side outlet by after fluid heating to 115 after pyroreaction DEG C; Enter the outer tube import of mud preheater II afterwards, flowed out from outer tube side outlet by after fluid heating to 224 after pyroreaction DEG C; To enter in mud preheater III by after high temperature fluid is heated to 395 DEG C after the reaction in overcritical water oxidization reactor afterwards, enter the mud import of overcritical water oxidization reactor; After printing and dyeing sludge mixes with oxygenant in the reactor, carry out supercritical water oxidation, organic pollutant is thoroughly decomposed into CO
2, H
2o, N
2small-molecule substance, the liberated heat of oxidation operation reaction simultaneously reacting by heating fluid to 550 DEG C;
3) high temperature fluid after the reaction in overcritical water oxidization reactor, after flowing through mud preheater III heat exchange pipeline, is cooled to 389 DEG C, flows out overcritical water oxidization reactor; Enter the pipe side-entrance of vapour generator afterwards, flow out from pipe side outlet after being cooled to 288 DEG C wherein; Enter pipe import in mud preheater II, flow out from inner tube outlet after being cooled to 198 DEG C wherein; Enter pipe import in softening water well heater afterwards, after releasing heat thermoplastic water, flow out from inner tube outlet after being cooled to 117 DEG C; Flow into the interior pipe import of mud preheater I subsequently, the printing and dyeing sludge of preheating outer tube, after reaction, fluid is cooled to 81 DEG C wherein; Enter the pipe side-entrance of mud well heater afterwards, transferring heat is to the printing and dyeing sludge of shell-side wherein, flows out after being cooled to 30 DEG C from pipe side outlet;
4) after the cooling of mud heater tube side outlet outflow, react rear clean fluid, enter capillary pressure reducer; High pressure fluid flows through the pressure-losses that capillary pressure reducer realizes 20MPa, and the remaining pressure-losses is born by pressure regulator valve.
Relative to prior art, the present invention has following beneficial effect:
System start-up phase, by electric heater preheating methanol solution, after preheating, methanol solution enters overcritical water oxidization reactor and oxygenant mixing afterfire heat release, the organic materials be used in pre-thermal reactor.System start-up phase adopts the methanol solution after electrically heated preheating as thermal source, and primary heater unit is simple, effectively prevent gas furnace as the coking carbon distribution problem in pipeline during thermal source; In addition, methanol solution high-temperature product after reactor combustion direct mixing with organic materials carries out preheating to it, and be the heat transfer process without wall, be the direct heat transfer between molecule, heat transfer efficiency is high.Thus improve system operation reliability, and reduce facility investment.
In sludge pretreatment part, in mud well heater, by fluid after reaction, mud is preheated to 75 DEG C, effectively reduces sewage sludge viscosity, and then improve mud flowable, reduce mud poor fluidity to high pressure mud surge pump proposed requirement.
By the deposition of soluble inorganic salt particle in conveying pipe and system device that control flow check rate of flow of fluid prevents insoluble particles of inorganic material and supercritical water from separating out, avoid solid particulate blocking pipe; Flow through capillary pressure reducer by fluid and realize system step-down, under overcoming large pressure reduction conditions, solid particulate is to the abrasion of step-down valve or blocking, improves the serviceability of system.
Reclaimed the oxidation heat liberation of mud organic substance by preheating material and the mode producing saturation steam, realize system self-heating.Carry out cascaded utilization of energy, realize capacity usage ratio and maximize, lifting system economy.
[accompanying drawing explanation]
Fig. 1 is system architecture schematic diagram of the present invention.
Number in the figure represents respectively: 1. sludge storage pool; 2. spiral pump; 3. mud well heater; 4. homogenizing emulsifying pump; 5. mud surge pump; 6. mud preheater I; 7. mud preheater II; 8. mud preheater III; 9. overcritical water oxidization reactor; 10. methanol solution storage tank; 11. methyl alcohol transferpumps; 12. methyl alcohol start electric heater; 13. liquid oxygen vessels; 14. low-temperature liquid oxygen pumps; 15. liquid oxygen gasifiers; 16. snubbers; 17. softening water tanks; 18. softening water pumps; 19. softening water well heaters; 20. vapour generators; 21. capillary pressure reducer; 22. pressure regulator valves; 23. line strainers; 24. liquid-collecting boxs.
[embodiment]
As shown in Figure 1, the supercritical water oxidation treatment system of a kind of printing and dyeing sludge of the present invention, comprise sludge pretreatment part, material regenerator section, hybrid reaction part, heat recovery section and step-down part, the mode of connection of devices in system is as follows:
Sludge pretreatment part comprises sludge storage pool 1, the outlet of sludge storage pool 1 and spiral pump 2 inlet communication, spiral pump 2 exports and is connected with mud well heater 3 shell-side inlet, and mud well heater 3 shell-side outlet connects homogenizing emulsifying pump 4 import, and homogenizing emulsifying pump 4 exports and high pressure mud surge pump 5 inlet communication.
Material regenerator section comprises methyl alcohol and starts electric heater 12 and mud preheater III 8, and the import of methyl alcohol startup electric heater 12 exports with high-pressure methanol transferpump 11 and is connected, and high-pressure methanol transferpump 11 import connects methanol solution storage tank 10 and exports.The entrance of mud preheater III 8 exports with mud preheater II 7 outer tube and is connected, and the import of mud preheater II 7 outer tube exports with mud preheater I 6 outer tube and is connected.Mud preheater I 6 outer tube import and high pressure mud surge pump 5 outlet.
Hybrid reaction part comprises overcritical water oxidization reactor 9, the oxygen intake of overcritical water oxidization reactor 9 exports with snubber 16 and is connected, snubber 16 import connects liquid oxygen gasifier 15 and exports, the methanol solution import of overcritical water oxidization reactor 9 is connected to outlet, the mud import of overcritical water oxidization reactor 9 and the outlet of mud preheater III 8 that methyl alcohol starts electric heater 12.Liquid oxygen vessel 13 provides low-temperature liquid oxygen pump 14 to connect liquid oxygen gasifier 15 entrance.
Heat recovery section comprises mud well heater 3 and low pressure softens water pump 18, the side-entrance of mud well heater 3 pipe is communicated with mud preheater I 6 inner tube outlet, in mud preheater I 6, pipe import is connected with softening water well heater 19 inner tube outlet, in softening water well heater 19, pipe import is connected with mud preheater II 7 inner tube outlet, in mud preheater II 7, pipe import is communicated with vapour generator 20 pipe side outlet, and the side-entrance of vapour generator 20 pipe is connected to overcritical water oxidization reactor 9 and exports.Low pressure is softened water pump 18 import and is exported with softening water tank 17 and be connected, low pressure is softened water pump 18 and is exported the import of connection softening water well heater 19 outer tube, the outlet of softening water well heater 19 outer tube is connected with vapour generator 20 shell-side inlet, and the saturation steam of generation exports from vapour generator 20 shell-side outlet.
Decompression portion is divided and is comprised pressure regulator valve 22, pressure regulator valve 22 import is connected to kapillary 21 and exports, kapillary 21 import is connected with mud well heater 3 pipe side outlet, and pressure regulator valve 22 exports and line strainer 23 inlet communication, and line strainer 23 outlet is connected to liquid-collecting box 24.In step-down part, after reaction, fluid flows through kapillary 21 to realize the step-down of high pressure fluid, and kapillary 21 outlet arranges pressure regulator valve 22, realizes the accurate control of system pressure.
Refer to shown in Fig. 1, the technology for supercritical water oxidation processing of a kind of printing and dyeing sludge of the present invention comprises:
1) when system starts, methyl alcohol and softening water enter methanol solution storage tank 10, be mixed with the methanol aqueous solution that concentration is 15wt%, after methanol aqueous solution is forced into 28MPa by methyl alcohol transferpump 11, enter methyl alcohol startup electric heater 12 and be heated to combustion initiation temperature 500 DEG C, then enter the methanol solution import of overcritical water oxidization reactor 9.After liquid oxygen in liquid oxygen vessel 13 is forced into 28MPa by low-temperature liquid oxygen pump 14, flow through after liquid oxygen gasifier 15 is vaporized, by snubber 16 with the oxidant stress eliminated low-temperature liquid oxygen pump and cause and flow rate fluctuation, enter the oxidant inlet of overcritical water oxidization reactor 9 afterwards.Clean water in liquid-collecting box 24 enters mud preheater I 6 outer tube after being forced into 28MPa by high pressure mud surge pump 5, flow through successively afterwards mud preheater II 7 outer tube, mud preheater III 8 laggard enter overcritical water oxidization reactor 9.In overcritical water oxidization reactor 9, ignition after methanol solution after heating mixes with oxygenant, after burning, high-temperature product carries out preheating to reactor, until fluid temperature (F.T.) reaches temperature of reaction 550 DEG C in reactor, the inlet feed now switching high pressure mud surge pump 5 is printing and dyeing sludge.Open the electric check valve between homogenizing emulsifying pump 4 to mud surge pump 5, close the electric check valve between liquid-collecting box 24 to mud surge pump 5.
2), when system is normally run, the fluid temperature (F.T.) in overcritical water oxidization reactor 9 is warming up to after 550 DEG C, carries out material switching.Printing and dyeing sludge in sludge storage pool 1, by spiral pump 2, is heated to 75 DEG C after entering mud well heater 3 shell-side inlet, reduces the viscosity of printing and dyeing sludge, and then increases its mobility.After flowing out from mud well heater 3 shell-side outlet, after the homogenized process of homogenizing emulsifying pump 4, flow into the import of high pressure mud surge pump 5, mud is transported to the outer tube side-entrance of mud preheater I 6 after being pressurized to 28MPa, is flowed out from outer tube side outlet by after fluid heating to 115 after pyroreaction DEG C.Enter the outer tube import of mud preheater II 7 afterwards, flowed out from outer tube side outlet by after fluid heating to 224 after pyroreaction DEG C.To enter in mud preheater III 8 by after high temperature fluid is heated to 395 DEG C after the reaction in overcritical water oxidization reactor 9 afterwards, enter the mud import of overcritical water oxidization reactor 9.After printing and dyeing sludge mixes with oxygenant in reactor 9, carry out supercritical water oxidation, organic pollutant is thoroughly decomposed into CO
2, H
2o, N
2deng small-molecule substance, the liberated heat of oxidation operation reaction simultaneously reacting by heating fluid to 550 DEG C.
3) high temperature fluid after the reaction in overcritical water oxidization reactor 9, after flowing through mud preheater III 8 heat exchange pipeline, is cooled to 389 DEG C, flows out overcritical water oxidization reactor.Enter the pipe side-entrance of vapour generator 20 afterwards, flow out from pipe side outlet after being cooled to 288 DEG C wherein.Enter pipe import in mud preheater II 7, flow out from inner tube outlet after being cooled to 198 DEG C wherein.Enter pipe import in softening water well heater 19 afterwards, after releasing heat thermoplastic water, flow out from inner tube outlet after being cooled to 117 DEG C.Flow into the interior pipe import of mud preheater I 6 subsequently, the printing and dyeing sludge of preheating outer tube, after reaction, fluid is cooled to 81 DEG C wherein.Enter the pipe side-entrance of mud well heater 3 afterwards, transferring heat is to the printing and dyeing sludge of shell-side wherein, flows out after being cooled to 30 DEG C from pipe side outlet.
4) after the cooling of mud well heater 3 pipe side outlet outflow, react rear clean fluid, enter capillary pressure reducer 21.High pressure fluid flows through the pressure-losses that capillary pressure reducer 21 can realize 20MPa, and the remaining pressure-losses (being less than 5MPa) is born by pressure regulator valve 22.Capillary pressure reducer is in conjunction with the mode of pressure regulator valve classification step-down, not only can prevent the too high and valve wear problem of the rate of flow of fluid in pressure regulator valve 22, can be realized the accurate control of system pressure by variable valve 22, kapillary is changed also very cheap when needed in addition simultaneously.