Treatment system and treatment method for radioactive organic waste

Abstract

The invention discloses a radioactive organic waste treatment system and method. The radioactive organic waste treatment system comprises a waste feeding system, a reforming reaction system, an oxidation treatment system, a tail gas treatment system and a washing liquid drying system. By means of the treatment system and method for the radioactive organic waste, volume reduction of the radioactive organic waste can be effectively achieved, the volume reduction ratio reaches up to 6 or above, stable solid waste particles enveloping 99% or above of radionuclides are formed, a large amount of nitric oxide and dioxin cannot be generated, and no secondary waste liquid is generated.

Description

Technical Field

[0001] The invention relates to a system and method for treating radioactive organic waste. Background Art

[0002] At present, the nuclear power industry is developing rapidly in China. The radioactive organic waste generated by the nuclear industry will eventually be treated by long-term isolation and storage, but this method involves high costs. Therefore, in order to reduce costs, the volume reduction treatment of radioactive organic waste generated by nuclear power plants and facilities involving nuclear chemical industry has become an important part before the disposal of these wastes.

[0003] At present, radioactive organic wastes generated by nuclear power plants and facilities involving nuclear chemicals, such as dry waste, radioactive waste resin, waste oil, etc., are mainly treated by physical means such as drying and overpressure, and the volume reduction ratio of the treatment process cannot be further improved. The existing technology also uses the method of "waste incineration" to reduce the volume of this type of waste, but it involves problems such as the difficulty of capturing radioactive nuclides, and cannot effectively make the waste treatment harmless. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects in the prior art that the volume reduction ratio cannot be further improved and the waste cannot be effectively treated harmlessly, and to provide a treatment system and method for radioactive organic waste. The present invention can achieve a high volume reduction ratio and efficient treatment of radioactive nuclides.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] The present invention provides a system for treating radioactive organic waste, comprising:

[0007] Waste feeding systems;

[0008] A reforming reaction system, the reforming reaction system comprising a reforming reactor, the reforming reactor comprising an upper cooling zone and a lower reaction zone which are interconnected, the cooling zone being provided with a cooling zone gas outlet, the reaction zone being provided with a waste feed port and a first waste particle discharge port, the waste feed system being connected with the waste feed port and used for conveying radioactive organic waste to the reforming reactor;

[0009] An oxidation treatment system, wherein the oxidation treatment system comprises a thermal oxidation furnace, wherein the thermal oxidation furnace comprises an upper oxidation chamber and a lower alkali washing quenching chamber which are interconnected, wherein the oxidation chamber is further provided with an oxidation chamber air inlet, wherein the cooling zone air outlet is connected with the oxidation chamber air inlet, and is used to transport the mixed gas obtained by the reforming reaction system to the thermal oxidation furnace, wherein the oxidation chamber is used to oxidize the mixed gas to form flue gas, and allow the flue gas to enter the alkali washing quenching chamber for cooling, wherein the alkali washing quenching chamber is provided with an alkali washing liquid inlet, an alkali washing liquid outlet and a quenching chamber air outlet;

[0010] An exhaust gas treatment system, wherein the exhaust gas treatment system is further provided with an exhaust gas inlet, a washing liquid inlet and a washing liquid outlet, the quench chamber outlet is connected to the exhaust gas inlet, and is used to transport the flue gas cooled by the alkali washing quench chamber to the exhaust gas treatment system, and the washing liquid outlet is connected to the alkali washing liquid inlet, and is used to recycle the washing liquid to the alkali washing quench chamber;

[0011] The washing liquid drying system, wherein the alkaline washing liquid outlet is connected to the washing liquid drying system, and is used for drying the alkaline washing liquid and the washing liquid into the first solid waste.

[0012] In the present invention, the waste feeding system preferably includes a waste resin feeding system and a waste oil feeding system, and the waste resin feeding system and the waste oil feeding system are respectively connected to the waste feeding port.

[0013] Preferably, a gas atomizer and a heat-insulating jacket are provided between the waste resin feeding system and the waste feeding port. The provision of a gas atomizer is beneficial to improving the dispersibility of the radioactive organic waste.

[0014] In the present invention, the reforming reactor is preferably a bubbling fluidized bed. Preferably, the lower part of the bubbling fluidized bed is a reaction section, and the upper part is an expansion section. The use of a bubbling fluidized bed can improve the heat transfer efficiency of the cross section. The reforming reactor includes an upper cooling zone and a lower reaction zone that are interconnected, which can provide a good gas-solid fluidized state space and sufficient reaction time when treating waste. The reforming reaction system is used to decompose and inorganicize the organic matter in the radioactive organic waste, and at the same time, more than 99% of the radioactive nuclides in the radioactive organic waste are solidified in the bed material and additives.

[0015] In the present invention, the radioactive organic waste treatment system preferably also includes a bed material and additive replenishing system, and the reaction zone is also provided with a bed material and additive feed port. The bed material and additive replenishing system is connected to the bed material and additive feed port for adding bed material and additives to the reaction zone.

[0016] In the present invention, the radioactive organic waste treatment system preferably also includes a bed material and additive replenishing system, and the reaction zone is also provided with a bed material feed inlet and an additive feed inlet. The bed material and additive replenishing system is respectively connected to the bed material feed inlet and the additive feed inlet, and is used to add bed material and additives to the reaction zone.

[0017] Preferably, the bed material and additive replenishing system also includes a bed material and additive storage tank and a bed material and additive unloader, wherein the bed material and additive storage tank is used to store bed material and additives, and the bed material and additive unloader is used to add the bed material and additives to the bed material and additive feed inlet.

[0018] Preferably, the reaction zone is also provided with a bed material feed inlet and an additive feed inlet, and the bed material and additive replenishing system also includes a bed material unloader and an additive unloader; the bed material unloader is connected to the bed material feed inlet for adding bed material to the reaction zone; the additive unloader is connected to the additive feed inlet for replenishing additives to the reaction zone.

[0019] In the present invention, a nozzle is preferably provided on the top of the cooling zone.

[0020] In the present invention, the reaction zone is preferably further provided with a gasifying agent inlet.

[0021] In the present invention, the material of the reforming reactor is preferably Hastelloy, stainless steel or carbon steel with corundum as refractory lining.

[0022] In the present invention, the lower part of the reaction zone is preferably provided with a furnace burner for preheating or adding fuel to the reaction furnace.

[0023] In the present invention, the reforming reaction system preferably also includes a cyclone separator and a high-temperature filter, the cyclone separator and the high-temperature filter are sequentially connected between the outlet of the cooling zone and the inlet of the oxidation chamber, and are used to perform two-stage filtration on the mixed gas passing through the cooling zone; a second waste particle discharge port is provided below the cyclone separator, which is used to discharge the second solid waste formed after the mixed gas is filtered once, and a third waste particle discharge port is provided below the high-temperature filter, which is used to discharge the third solid waste formed after the mixed gas is filtered twice. The present invention adopts two-stage filtration to filter out solid particles with a particle size greater than 0.03 microns in the mixed gas.

[0024] In the present invention, the oxidation chamber is preferably further provided with an oxidation chamber gas inlet, and the oxidation chamber gas inlet is used to introduce natural gas and air.

[0025] In the present invention, the exhaust gas treatment system is preferably provided with a spray washing tower, a denitration reaction tower, a high-efficiency filter and a chimney which are interconnected in sequence, which are respectively used to desulfurize, denitrify, filter and discharge the flue gas cooled by the alkali washing quench chamber, and the exhaust gas inlet and the washing liquid outlet are arranged on the spray washing tower.

[0026] Preferably, an exhaust fan is also provided between the high efficiency filter and the chimney.

[0027] Preferably, a recovery device is provided between the denitration reaction tower and the high-efficiency filter. The recovery device is used to recover the moisture in the flue gas, thereby reducing the burden on the high-efficiency filter and the exhaust fan. After the moisture in the flue gas is recovered, the resistance of the flue gas when passing through the high-efficiency filter and the exhaust fan can be reduced, thereby improving the efficiency.

[0028] In the present invention, the chimney is preferably provided with an exhaust emission monitor and a radiation monitor for online analysis and detection of sulfur dioxide, nitrogen oxides, solid particulate matter concentration, radiation dose, etc. in the exhaust gas to determine whether they meet environmental emission requirements.

[0029] In the present invention, the first solid waste is directly generated after passing through the washing liquid drying system, and no secondary waste liquid is generated, so the treatment is simple.

[0030] The present invention also provides a method for treating radioactive organic waste, which uses the above-mentioned radioactive organic waste treatment system and comprises the following steps:

[0031] S1, feeding stage: placing the radioactive organic waste in the waste feeding system;

[0032] S2, steam reforming reaction stage: the radioactive organic waste is transported from the waste feeding system to the reaction zone of the reforming reactor through the waste feeding port for reaction, and then cooled in the cooling zone, the reaction temperature of the reaction zone is set at 650° C.-900° C., and the reaction pressure of the reaction zone is set at -1-10 kPaG, so that the radioactive organic waste forms a mixed gas after reaction and cooling;

[0033] S3, oxidation treatment stage: the temperature of the oxidation chamber is set to 850-1150°C, the residence time is at least 2s, the mixed gas first enters the oxidation chamber to obtain oxidized mixed gas, and the oxidized mixed gas enters the alkali washing quenching chamber and is quickly cooled to below 60-95°C to form flue gas;

[0034] S4, tail gas treatment stage: the flue gas enters the tail gas treatment system for purification and then is discharged;

[0035] S5, washing liquid drying stage: the washing liquid of the tail gas treatment system flows back to the alkali washing quenching chamber and flows to the washing liquid drying system together with the alkali washing liquid in the alkali washing quenching chamber for drying to form the first solid waste.

[0036] In the present invention, the radioactive organic waste preferably includes waste resin, waste activated carbon and waste oil.

[0037] Wherein, the waste resin preferably comprises anion exchange resin and / or cation exchange resin, wherein the chemical formula of the anion exchange resin is C 34 H 52 N 3 O 3 The chemical formula of the cation exchange resin is C 25 H 25 S 3 O 9 .

[0038] Among them, the BO contained in the waste resin 3 The mass fraction of is preferably 2%-8%, for example 6%.

[0039] The total content of cesium, strontium and cobalt in the waste resin is preferably 0.2-100 g / m 3 , for example 1g / m 3 .

[0040] The cesium content in the waste resin is preferably 0.2 g / m 3 .

[0041] The content of strontium in the waste resin is preferably 0.2 μg / m 3 .

[0042] The cobalt content in the waste resin is preferably 0.01 g / m 3 .

[0043] Wherein, the mass fraction of lithium in the waste resin is preferably 0.1%.

[0044] Among them, the waste oil preferably includes hydraulic oil and / or lubricating oil, and the components of the waste oil preferably include one or more of aromatic hydrocarbons, ethers, polycyclic aromatic hydrocarbons, fluorine-containing substances and acidic substances, for example, one or more of benzene, toluene, xylene, glycol, isobutanol, polycyclic aromatic hydrocarbons, fluorides, sulfides and organic acids.

[0045] In the present invention, the waste feeding system preferably includes a waste resin feeding system and a waste oil feeding system, and step S1 preferably includes one of the following situations:

[0046] (a) the radioactive organic waste includes waste resin, and the waste resin enters the waste resin feeding system;

[0047] (b) the radioactive organic waste includes waste resin and waste oil, and the waste resin and the waste oil are fed together; wherein the feeding together means feeding at the same time;

[0048] (c) The radioactive organic waste includes waste resin and waste oil, the waste resin enters the waste resin feeding system, and the waste oil enters the waste oil feeding system;

[0049] (d) The radioactive organic waste includes waste resin and waste activated carbon. After being mixed with water in the waste resin feeding system, the waste resin and the waste activated carbon enter the reforming reaction system in the form of slurry, wherein the mass ratio of the waste resin to the water is preferably 1:(1-2).

[0050] In the present invention, step S2 preferably further includes a gasifying agent, and the gasifying agent is uniformly input into the lower part of the reaction zone through a gasifying agent inlet.

[0051] Wherein, the gasifying agent is preferably air, oxygen and superheated water vapor; or, the gasifying agent is preferably air and superheated water vapor; or, the gasifying agent is preferably air.

[0052] In the present invention, in step S2, preferably, clean water and atomizing gas nitrogen are used to cool the mixed gas.

[0053] In the present invention, in step S2, preferably, the temperature of the air outlet of the cooling zone is lower than 600°C.

[0054] In the present invention, in step S2, preferably, the fourth solid waste is discharged and packaged through the first waste particle discharge port, the second solid waste is discharged and packaged through the second waste particle discharge port, and the third solid waste is discharged and packaged through the third waste particle discharge port; wherein the particle size of the solid particles in the third solid waste is greater than 0.03 microns. wherein the solidified elements in the fourth solid waste, the second solid waste and the third solid waste preferably include potassium, sodium, calcium, lithium, cesium, strontium, cobalt, boron, sulfur and chlorine.

[0055] In the present invention, the mixed gas preferably includes one or more of nitrogen, methane, carbon monoxide, carbon dioxide, hydrogen and hydrogen sulfide.

[0056] In the present invention, in step S2, the bed material used preferably comprises alumina, wherein the particle size of the alumina is preferably 100-1000 microns. The bed material can be used as a fluidized medium of a fluidized bed reforming reactor and can also solidify radionuclides.

[0057] In the present invention, in step S2, preferably, an additive can also be used, and the additive is preferably kaolin of the clay type, and the particle size of the kaolin of the clay type is preferably 100-1000 microns. The additive can be used to solidify metal or non-metal elements such as radionuclides.

[0058] In the present invention, the reaction involved in step S2 mainly includes:

[0059] Decomposition of organic matter: C x H y O z →C+CH 4 +CO+H 2 ;

[0060] Water gas reaction: H 2 O+C→H 2 +CO;

[0061] CO shift reaction: CO+H 2 O→CO 2 +H 2 ;

[0062] Carbon oxidation reaction: C+O 2 →CO 2 ;

[0063] CO oxidation reaction: 2CO+O 2 →2CO 2 ;

[0064] H 2 Oxidation reaction: 2H 2 +O 2 →2H 2 O;

[0065] First nitric acid conversion reaction: 2NO 3 +3C→N 2 +3CO 2 ;

[0066] Second nitric acid conversion reaction: 2NO 3 +6H 2 →N 2 +6H 2 O;

[0067] The first hydrocarbon reforming reaction: C 2 H 4 +2H 2 O→2CO+4H 2 ;

[0068] Second hydrocarbon reforming reaction: C 6 H 6 +6H2 O→6CO+9H 2 .

[0069] In the present invention, step S2 also involves a mineralization reaction, that is, the additive and the inorganic matter in the reforming residue form a new mineralization phase in the reforming furnace, which can make the radioactive nuclides in the waste well encapsulated in the mineralization product, for example, including the following reactions:

[0070] Na+Al 2 O 3 -2SiO 2 →Na 2 O-Al 2 O 3 -2SiO;

[0071] Na+K+Al 2 O 3 -2SiO 2 →NaKO-Al 2 O 3 -2SiO;

[0072] Na+SO 4 +Al 2 O 3 -2SiO 2 →NaSO 4 -(Na 2 O-Al 2 O 3 -2SiO 2 ) 6 ;

[0073] Na+Cl+Al 2 O 3 -2SiO 2 →2NaCl-(Na 2 O-Al 2 O 3 -2SiO 2 ) 6 ;

[0074] Na+F+Al 2 O 3 -2SiO 2 →2NaF-(Na 2 O-Al 2 O 3 -2SiO 2 ) 6 ;

[0075] Na+Al 2 O 3 →NaAlO 2 .

[0076] In the present invention, natural gas and air are preferably introduced into step S3 to fully oxidize and burn the mixed gas.

[0077] In the present invention, the oxidized mixed gas preferably includes carbon dioxide and water vapor.

[0078] In the present invention, in step S3, the temperature of the oxidation chamber is preferably 1100°C.

[0079] In the present invention, in step S3, the alkaline washing liquid used in the alkaline washing quenching chamber preferably comprises sodium hydroxide. The alkaline washing liquid is used to absorb the acidic gas in the mixed gas, and the acidic gas is, for example, sulfur dioxide and / or hydrogen chloride.

[0080] In the present invention, the flue gas preferably includes nitrogen, carbon dioxide, acidic gas and nitrogen oxides. The acidic gas is, for example, sulfur dioxide. The volume percentage of sulfur dioxide is preferably 5%-20%, and the volume percentage of carbon dioxide is preferably 5%-30%.

[0081] In the present invention, in step S4, preferably, the flue gas is sequentially desulfurized, denitrified, filtered and discharged.

[0082] The desulfurization method is preferably alkaline wet desulfurization, and the alkaline wet desulfurization preferably adopts direct mixing spray alkaline washing; the desulfurization agent used in the desulfurization preferably includes sodium hydroxide.

[0083] The temperature of the denitration is preferably 250-330°C; the denitration agent used in the denitration is preferably ammonia water; and the denitration step is used to remove nitrogen oxides in flue gas.

[0084] Wherein, the filtration temperature is preferably 120-150°C.

[0085] Wherein, the discharge temperature is preferably 100-140°C.

[0086] In the present invention, the elements solidified in the first solid waste preferably include potassium, sodium, calcium, lithium, cesium, strontium, cobalt, boron, sulfur and chlorine.

[0087] In the present invention, the first solid waste preferably includes nepheline, hematite, sodalite and pyroxene; wherein the nepheline has a hexagonal structure and a molecular formula of NaAlSiO 4 The hematite has an orthorhombic structure and a molecular formula of NaAlSiO 2 .

[0088] Wherein, the pyroxene is a cubic sodalite structure, and the molecular formula is Na 8 [AlSiO4 ] 6 SO 4 .

[0089] Wherein, the molecular formula of the sodalite is M 8 (Al 6 Si 6 O 24 )X 2 , where M is an alkaline cation, such as Cs + , K + 、Na + , Ca 2+ ; X is a monovalent anion, a monovalent anion or a divalent oxygen anion, for example Br - , Cl - ,I - , TcO 4 - 、ReO 4 - 、SO 4 2- .

[0090] Wherein, the mass percentage of the nepheline and the hematite to the mass percentage of the first solid waste is preferably 60%-80%.

[0091] Wherein, the mass percentage of the sodalite to the mass percentage of the first solid waste is preferably 5%-10%.

[0092] The mass percentage of the pyrophyllite to the mass percentage of the first solid waste is preferably 6%-12%.

[0093] The positive and progressive effects of the present invention are:

[0094] A partial redox reaction occurs in the reforming reaction system adopted by the present invention, so that the organic matter in the radioactive organic waste is gasified, chain-broken and decomposed, and the radioactive elements therein are solidified in the solid bed material and additives, so as to achieve volume reduction of the radioactive organic waste, with a volume reduction ratio of more than 6, and to form stable solid waste particles enveloping more than 99% of the radioactive nuclides, so as to achieve efficient treatment of the radioactive organic waste.

[0095] Compared with the incineration reaction in the prior art, the present invention does not produce a large amount of nitrogen oxides and dioxins, no secondary waste liquid is generated, and the exhaust gas meets the standards required by national and local laws and regulations. The mixed gas generated in the reforming reaction system of the present invention contains a certain amount of combustible gas, which can be used in the subsequent oxidation treatment system, thereby reducing costs.

[0096] The system of the present invention can achieve a waste resin processing capacity of more than 60 L / h, that is, a waste resin processing capacity of more than 50 kg / h. BRIEF DESCRIPTION OF THE DRAWINGS

[0097] Figure 1 This is the treatment system for radioactive organic waste in Examples 1-3.

[0098] The reference numerals are as follows:

[0099] 1- reforming reactor; 101- cooling zone; 102- reaction zone; 2- cyclone separator; 3- high temperature filter; 4- thermal oxidation furnace; 401- oxidation chamber; 402- alkali washing quenching chamber; 5- spray washing tower; 6- denitration reaction tower; 7- high efficiency filter; 8- bed material unloader; 9- additive unloader; 10- waste feeding system; 11- washing liquid drying system; 12- waste collection tank agitator; 13- waste feeding tank; 14- waste Additive feed tank; 15-pretreatment system; 16-cooler; 17-first heater; 18-condenser; 19-demister; 20-second heater; 21-exhaust fan; 22-salt liquid storage tank; 23-spray dryer; 24-air heater; 25-bag filter; 26-superheater; 27-sodium hydroxide storage tank; 1001-waste raw material feed port; 1002-gasification agent feed port; 1003-waste additive feed port. DETAILED DESCRIPTION

[0100] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0101] Example 1

[0102] The radioactive organic waste treatment system of Example 1 is as follows Figure 1 As shown, it comprises: a waste feeding system 10 and a bed material and additive replenishing system, the bed material and additive replenishing system further comprises a bed material unloader 8 and an additive unloader 9; the bed material unloader 8 is connected to the bed material feed port, and is used to add bed material to the reaction zone 102; the additive unloader 9 is connected to the additive feed port, and is used to replenish additives to the reaction zone 102; wherein the waste feeding system 10 comprises a waste collection tank agitator 12, two parallel waste feeding tanks 13, and a waste additive feeding tank 14; the bed material unloader 8 is also connected to a pre-treatment system 15;

[0103] The reforming reaction system comprises a reforming reactor 1, a cyclone separator 2 and a high-temperature filter 3. The reforming reactor 1 comprises an upper cooling zone 101 and a lower reaction zone 102 which are interconnected. The cooling zone 101 is provided with a cooling zone outlet, and the reaction zone 102 is provided with a waste feed port and a first waste particle discharge port. The waste feed system 10 is connected with the waste feed port, and is used to transport radioactive organic waste to the reforming reactor 1; the cyclone separator 2 and the high-temperature filter 3 are sequentially connected between the cooling zone outlet and the oxidation chamber inlet, and are used to perform two-stage filtration on the mixed gas passing through the cooling zone 101; a second waste particle discharge port is provided below the cyclone separator 2, and is used to discharge the second solid waste formed after the mixed gas is filtered once, and a third waste particle discharge port is provided below the high-temperature filter 3, and is used to discharge the third solid waste formed after the mixed gas is filtered twice;

[0104] The oxidation treatment system includes a thermal oxidation furnace 4, which includes an upper oxidation chamber 401 and a lower alkali washing quenching chamber 402 which are interconnected. The oxidation chamber 401 is also provided with an oxidation chamber air inlet, and a cooling zone air outlet is connected to the oxidation chamber air inlet, which is used to transport the mixed gas obtained by the reforming reaction system to the thermal oxidation furnace 4. The oxidation chamber 401 is used to oxidize the mixed gas to form flue gas, and allow the flue gas to enter the alkali washing quenching chamber 402 for cooling. The alkali washing quenching chamber 402 is provided with an alkali washing liquid inlet, an alkali washing liquid outlet and a quenching chamber air outlet; a cooler 16 is also provided between the oxidation treatment system and the tail gas treatment system;

[0105] The tail gas treatment system is also provided with a tail gas inlet, a washing liquid inlet and a washing liquid outlet. The quench chamber outlet is connected to the tail gas inlet for conveying the flue gas cooled by the alkali washing quench chamber 402 to the tail gas treatment system. The washing liquid outlet is connected to the alkali washing liquid inlet for recycling the washing liquid to the alkali washing quench chamber 402. The tail gas treatment system also includes a sodium hydroxide storage tank 27, which is connected to the alkali washing quench chamber 402.

[0106] The tail gas treatment system is provided with a spray scrubber 5, a first heater 17, a denitration reaction tower 6, a condenser 18, a demister 19, a second heater 20, a high efficiency filter 7, an exhaust fan 21 and a chimney in sequence, which are connected to each other, and are used to treat and discharge the flue gas cooled in the alkali washing quenching chamber 402. The tail gas inlet and the washing liquid outlet are arranged on the spray scrubber 5;

[0107] The washing liquid drying system 11, the alkaline washing liquid outlet is connected to the washing liquid drying system 11 through the salt solution storage tank 22, and is used to dry the alkaline washing liquid and the washing liquid into the first solid waste, wherein the washing liquid drying system 11 includes a spray dryer 23, an air heater 24 and a bag filter 25.

[0108] Example 2

[0109] Embodiment 2 adopts the radioactive organic waste treatment system of embodiment 1, and its radioactive organic waste treatment method comprises the following steps:

[0110] S1, feeding stage: placing radioactive organic waste in the waste feeding system 10;

[0111] S2, steam reforming reaction stage: the radioactive organic waste is transported from the waste feeding system 10 through the waste feeding port to the reaction zone 102 of the reforming reactor 1 for reaction, and then cooled in the cooling zone 101. The reaction temperature of the reaction zone 102 is set at 700-750°C, and the reaction pressure of the reaction zone 102 is set at 7-8kPaG, so that the radioactive organic waste forms a mixed gas after reaction and cooling; the temperature of the gas outlet of the cooling zone is lower than 600°C; the fourth solid waste is discharged and packaged through the first waste particle discharge port, the second solid waste is discharged and packaged through the second waste particle discharge port, and the third solid waste is discharged and packaged through the third waste particle discharge port; the bed material used includes alumina, wherein the particle size of the alumina is 100-1000 microns; the additive used is clay-type kaolin, and the particle size of the clay-type kaolin is 100-1000 microns.

[0112] S3, oxidation treatment stage: the temperature of the oxidation chamber 401 is set to at least 1100° C., and the residence time is at least 2 seconds. The mixed gas first enters the oxidation chamber 401 to obtain an oxidized mixed gas. The oxidized mixed gas enters the alkali washing quenching chamber 402 and is quickly cooled to below 90° C. to form flue gas; the alkali washing liquid used in the alkali washing quenching chamber 402 is sodium hydroxide;

[0113] S4, tail gas treatment stage: the flue gas is desulfurized, denitrated, filtered and discharged in sequence; the desulfurization method is alkaline wet desulfurization, using direct mixing spray alkaline washing, the desulfurizer used for desulfurization is sodium hydroxide; the denitrification temperature is 300℃, the denitrification agent used for denitrification is ammonia water; the filtration temperature is 130℃; the discharge temperature is 110℃;

[0114] S5, washing liquid drying stage: the washing liquid of the tail gas treatment system flows back to the alkali washing quenching chamber 402 and flows to the washing liquid drying system 11 together with the alkali washing liquid in the alkali washing quenching chamber 402 for drying to form the first solid waste.

[0115] The waste raw material feed port 1001 is used to feed radioactive organic waste, and the waste additive feed port 1003 is used to feed waste additives, wherein the waste additives include aluminum hydroxide and iron hydroxide, and the radioactive organic waste includes waste resin and waste activated carbon. After the waste resin and waste activated carbon are mixed with water in the waste resin feed system, they enter the reforming reaction system in the form of slurry, wherein the mass ratio of the waste resin to water is 1:1;

[0116] Among them, the gasifying agent feed port 1002 and the superheater 26 are sequentially connected to the reaction zone 102 for introducing air, oxygen and superheated water vapor;

[0117] The radioactive organic waste treated in Example 2 is prepared according to the following materials and material ratios:

[0118] Material A: anionic resin, BO 3 The mass fraction is 24%;

[0119] Material B: lithium-type cationic resin, Li mass fraction is 1.8%;

[0120] Material D: cationic resin raw material;

[0121] Material E: anionic resin raw material;

[0122] Material F: Cesium Strontium Cobalt pretreated cationic resin, Cesium Strontium Cobalt content is 250g / m 3 .

[0123] The ingredients of 100 kg of radioactive organic waste in Example 2 are as shown in Table 1 below:

[0124] Table 1

[0125] Material A Material B Material D Material E Material F Example 2 23.5kg 5.3kg 26.5kg 23.5kg 21.2kg

[0126] After the above ingredients, the boron (BO 3 ) has a mass fraction of 6%, 10% lithium-type cationic resin, that is, the mass fraction of lithium in the radioactive organic waste is 0.1%, and the cesium strontium cobalt content is 100g / m 3 .

[0127] The feed rate of radioactive organic waste is 2L / min. The bed material amount and other process parameters of the reforming reactor are adjusted according to the actual situation. The treatment system is continuously fed for 12h, with a cumulative feeding frequency of 6 times, a total of 600kg of feeding, and the resin processing capacity of the reforming furnace is 50kg / h. During this period, 3 samplings of solid reaction residue and flue gas washing liquid and 1 sampling of bed material were completed. During this period, the monitoring of exhaust emissions (SOx, NOx, etc.) was completed by online CEMS, and the exhaust gas treatment system met the standard specifications for the treatment of SOx, NOx, etc.

[0128] The mixed gas generated in step S2 is listed in Table 2 below, wherein the mixed gas also includes a very small amount of hydrogen sulfide.

[0129] Table 2

[0130]

[0131] In Example 2, a steam reforming reaction occurs in the reforming reactor, and the generated mixed gas is nitrogen, methane, carbon monoxide, carbon dioxide, hydrogen and hydrogen sulfide. Compared with conventional incineration reactions, it does not produce a large amount of nitrogen oxides and dioxins, and the above-mentioned mixed gas includes some combustible gases, which can reduce the use of subsequent combustion-supporting gases introduced into the oxidation chamber to save costs; at the same time, the composition of the mixed gas generated in the reforming reactor is stable, which is conducive to the stable operation of the entire system.

[0132] According to statistics and calculations, the final volume reduction ratio of Example 2 is 6.5:1; the nuclide inclusion rate is greater than 99%, the cesium inclusion rate is 99.99%, the strontium inclusion rate is 99.97%, and the cobalt inclusion rate is 99.99%.

[0133] The volume reduction ratio is the ratio of the total volume of radioactive organic waste to be treated to the total volume of solid waste.

[0134] The nuclide inclusion rate is calculated as follows: nuclide inclusion rate = 100% - (total mass of nuclides in the washing liquid after the tail gas is washed / total mass of nuclides in the radioactive organic waste) × 100%.

[0135] The inclusion rate of a certain element is calculated as follows: 100% - (the mass of a certain nuclide in the washing liquid after the tail gas is washed / the total mass of a certain nuclide in the radioactive organic waste) × 100%.

[0136] Example 3

[0137] Embodiment 3 adopts the radioactive organic waste treatment system of embodiment 1, and its radioactive organic waste treatment method comprises the following steps:

[0138] S1, feeding stage: placing radioactive organic waste in the waste feeding system 10;

[0139] S2, steam reforming reaction stage: the radioactive organic waste is transported from the waste feeding system 10 through the waste feeding port to the reaction zone 102 of the reforming reactor 1 for reaction, and then cooled in the cooling zone 101. The reaction temperature of the reaction zone 102 is set at 700-750°C, and the reaction pressure of the reaction zone 102 is set at 7-8kPaG, so that the radioactive organic waste forms a mixed gas after reaction and cooling; the temperature of the gas outlet of the cooling zone is lower than 600°C; the fourth solid waste is discharged and packaged through the first waste particle discharge port, the second solid waste is discharged and packaged through the second waste particle discharge port, and the third solid waste is discharged and packaged through the third waste particle discharge port; the bed material used includes alumina, wherein the particle size of the alumina is 100-1000 microns; the additive used is clay-type kaolin, and the particle size of the clay-type kaolin is 100-1000 microns.

[0140] S3, oxidation treatment stage: the temperature of the oxidation chamber 401 is set to at least 1100° C., and the residence time is at least 2 seconds. The mixed gas first enters the oxidation chamber 401 to obtain an oxidized mixed gas. The oxidized mixed gas enters the alkali washing quenching chamber 402 and is quickly cooled to below 90° C. to form flue gas; the alkali washing liquid used in the alkali washing quenching chamber 402 is sodium hydroxide;

[0141] S4, tail gas treatment stage: the flue gas is desulfurized, denitrated, filtered and discharged in sequence; the desulfurization method is alkaline wet desulfurization, using direct mixing spray alkaline washing, the desulfurizer used for desulfurization is sodium hydroxide; the denitrification temperature is 300℃, the denitrification agent used for denitrification is ammonia water; the filtration temperature is 130℃; the discharge temperature is 110℃;

[0142] S5, washing liquid drying stage: the washing liquid of the tail gas treatment system flows back to the alkali washing quenching chamber 402 and flows to the washing liquid drying system 11 together with the alkali washing liquid in the alkali washing quenching chamber 402 for drying to form the first solid waste.

[0143] The waste raw material feed port 1001 is used to feed radioactive organic waste, and the waste additive feed port 1003 is used to feed waste additives, wherein the waste additives include aluminum hydroxide and iron hydroxide, and the radioactive organic waste includes waste resin and waste activated carbon. After the waste resin and waste activated carbon are mixed with water in the waste resin feed system, they enter the reforming reaction system in the form of slurry, wherein the mass ratio of the waste resin to water is 1:1;

[0144] Among them, the gasifying agent feed port 1002 and the superheater 26 are sequentially connected to the reaction zone 102 for introducing air, oxygen and superheated water vapor;

[0145] The radioactive organic waste treated in Example 3 is prepared according to the following materials and material ratios:

[0146] Material A: anionic resin, BO 3 The mass fraction is 24%;

[0147] Material B: lithium-type cationic resin, Li mass fraction is 1.8%;

[0148] Material C: Cesium Strontium Cobalt pretreated cationic resin, Cesium Strontium Cobalt content is 50g / m 3 ;

[0149] Material D: cationic resin raw material;

[0150] Material E: anionic resin raw material.

[0151] The ingredients of 100 kg of radioactive organic waste in Example 3 are as shown in Table 3 below:

[0152] Table 3

[0153] Material A Material B Material C Material D Material E Example 3 7.8kg 5.3kg 2.1kg 45.5kg 39.2kg

[0154] After the above ingredients are prepared, the radioactive organic waste in Example 3 contains boron (BO 3 ) has a mass fraction of 2%, 10% lithium-type cationic resin, that is, the mass fraction of lithium in the radioactive organic waste is 0.1%, and the cesium strontium cobalt content is 1g / m 3 .

[0155] The feed rate of radioactive organic waste is 2L / min. The bed material amount and other process parameters of the reforming reactor 1 are adjusted according to the actual situation. The waste resin is continuously fed for 72 hours. A total of 4100kg of waste resin is fed, and the resin processing capacity of the reforming furnace is 57kg / h. 30 minutes before the waste resin feed is stopped, waste oil is input into the treatment system by a waste oil pump, and the waste oil is continued to be fed together with the waste resin. The waste oil feed rate is 6kg / h. The tail gas treatment system has an effective alkali desulfurization and ammonia denitrification operation time of 4 hours. The entire treatment system has a treatment time of 74 hours, and it is safely shut down after a total of 78 hours of operation.

[0156] During the period, six samples of solid reaction residue and flue gas scrubbing liquid were taken and retained, and one sample of bed material was taken and retained. During the period, the monitoring of tail gas emissions (SOx, NOx, etc.) was completed by online CEMS, and the SOx emission concentration in the tail gas could be stably controlled at <50mg / m 3 , NOx emission concentration can be stably controlled at <50mg / m 3 The exhaust gas treatment system meets the standard specifications for the treatment of SOx, NOx, etc.

[0157] The mixed gas produced after the steam reforming reaction is nitrogen, methane, carbon monoxide, carbon dioxide, hydrogen and hydrogen sulfide.

[0158] According to statistics and calculations, the final volume reduction ratio of Example 3 is greater than 6.28:1; the nuclide inclusion rate is greater than 99%, the cesium inclusion rate is 99.99%, the strontium inclusion rate is 99.78%, and the cobalt inclusion rate is 99.9%.

[0159] The volume reduction ratio is the ratio of the total volume of radioactive organic waste treated to the total volume of solid waste.

[0160] The nuclide inclusion rate is calculated as follows: nuclide inclusion rate = 100% - (total mass of nuclides in the washing liquid after the tail gas is washed / total mass of nuclides in the radioactive organic waste) × 100%.

[0161] The inclusion rate of a certain element is calculated as follows: 100% - (the mass of a certain nuclide in the washing liquid after the tail gas is washed / the total mass of a certain nuclide in the radioactive organic waste) × 100%.

[0162] The treatment system of the present invention can be used for the steam reforming process of domestic nuclear power plant waste (waste resin, waste oil, etc.), meets various process conditions in the fluidized bed steam reforming treatment technology, and meets the following technical indicators:

[0163] (1) Waste resin processing capacity ≥ 50kg / h;

[0164] (2) Volume reduction ratio ≥ 6;

[0165] (3) Main radioactive elements that can be treated: Cs, Sr, Co;

[0166] (4) Nuclide inclusion rate ≥ 99%;

[0167] (5) Exhaust emissions meet the requirements of standards and specifications;

[0168] (6) The design temperature of the steam reforming reaction stage shall not be less than 600°C, and the design pressure shall not be less than 0.02MPa.

[0169] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A system for treating radioactive organic waste, characterized in that: include: Waste feeding systems; A reforming reaction system, the reforming reaction system comprising a reforming reactor, the reforming reactor comprising an upper cooling zone and a lower reaction zone which are interconnected, the cooling zone being provided with a cooling zone gas outlet, the reaction zone being provided with a waste feed port and a first waste particle discharge port, the waste feed system being connected with the waste feed port and used for conveying radioactive organic waste to the reforming reactor; An oxidation treatment system, wherein the oxidation treatment system comprises a thermal oxidation furnace, wherein the thermal oxidation furnace comprises an upper oxidation chamber and a lower alkali washing quenching chamber which are interconnected, wherein the oxidation chamber is further provided with an oxidation chamber air inlet, wherein the cooling zone air outlet is connected with the oxidation chamber air inlet, and is used to transport the mixed gas obtained by the reforming reaction system to the thermal oxidation furnace, wherein the oxidation chamber is used to oxidize the mixed gas to form flue gas, and allow the flue gas to enter the alkali washing quenching chamber for cooling, wherein the alkali washing quenching chamber is provided with an alkali washing liquid inlet, an alkali washing liquid outlet and a quenching chamber air outlet; An exhaust gas treatment system, wherein the exhaust gas treatment system is further provided with an exhaust gas inlet, a washing liquid inlet and a washing liquid outlet, the quench chamber outlet is connected to the exhaust gas inlet, and is used to transport the flue gas cooled by the alkali washing quench chamber to the exhaust gas treatment system, and the washing liquid outlet is connected to the alkali washing liquid inlet, and is used to recycle the washing liquid to the alkali washing quench chamber; The washing liquid drying system, wherein the alkaline washing liquid outlet is connected to the washing liquid drying system, and is used for drying the alkaline washing liquid and the washing liquid into the first solid waste.

2. The radioactive organic waste treatment system according to claim 1, characterized in that: The waste feeding system comprises a waste resin feeding system and a waste oil feeding system, and the waste resin feeding system and the waste oil feeding system are respectively connected to the waste feeding port; wherein a gas atomizer and a heat insulating jacket are preferably arranged between the waste resin feeding system and the waste feeding port; And / or, the reforming reactor is a bubbling fluidized bed, wherein, preferably, the lower part of the bubbling fluidized bed is a reaction section, and the upper part is an expansion section.

3. The radioactive organic waste treatment system according to claim 1, characterized in that: It also includes a bed material and additive replenishing system, which includes a bed material and additive storage tank and a bed material and additive discharger; wherein the reaction zone is also provided with a bed material and additive feed port, and the bed material and additive replenishing system is connected to the bed material and additive feed port for adding bed material and additive to the reaction zone; Alternatively, the reaction zone is further provided with a bed material feed port and an additive feed port, and the bed material and additive replenishing system is connected to the bed material feed port and the additive feed port, respectively, for adding bed material and additive to the reaction zone; Alternatively, the reaction zone is further provided with a bed material feed inlet and an additive feed inlet, and the bed material and additive replenishing system further comprises a bed material unloader and an additive unloader; the bed material unloader is connected to the bed material feed inlet for adding bed material to the reaction zone; the additive unloader is connected to the additive feed inlet for replenishing additives to the reaction zone.

4. The radioactive organic waste treatment system according to claim 1, characterized in that: It also includes a cyclone separator and a high-temperature filter, which are connected in sequence between the air outlet of the cooling zone and the air inlet of the oxidation chamber, and are used to perform two-stage filtration on the mixed gas passing through the cooling zone; a second waste particle discharge port is provided below the cyclone separator, which is used to discharge the second solid waste formed after the mixed gas is filtered once, and a third waste particle discharge port is provided below the high-temperature filter, which is used to discharge the third solid waste formed after the mixed gas is filtered twice.

5. The radioactive organic waste treatment system according to claim 1, characterized in that: The oxidation chamber is also provided with an oxidation chamber gas inlet, and the oxidation chamber gas inlet is used to introduce natural gas and air; And / or, a nozzle is provided on the top of the cooling zone; And / or, the reaction zone is further provided with a gasifying agent inlet; and / or, the reforming reactor is made of Hastelloy, stainless steel or carbon steel with corundum as refractory lining; And / or, a furnace burner is disposed at the lower portion of the reaction zone for preheating or replenishing fuel to the reaction furnace.

6. The radioactive organic waste treatment system according to claim 1, characterized in that: The tail gas treatment system is provided with a spray scrubber, a denitration reaction tower, a high-efficiency filter and a chimney which are connected in sequence, and are respectively used to desulfurize, denitrate, filter and discharge the flue gas cooled in the alkali washing quenching chamber, and the tail gas inlet and the washing liquid outlet are arranged on the spray scrubber; wherein an exhaust fan is preferably arranged between the high-efficiency filter and the chimney; And / or, the chimney is provided with an exhaust emission monitor and a radiation monitor.

7. A method for treating radioactive organic waste, characterized in that: The method adopts a radioactive organic waste treatment system as claimed in any one of claims 1 to 6, comprising the following steps: S1, feeding stage: placing the radioactive organic waste in the waste feeding system; S2, steam reforming reaction stage: the radioactive organic waste is transported from the waste feeding system to the reaction zone of the reforming reactor through the waste feeding port for reaction, and then cooled in the cooling zone, the reaction temperature of the reaction zone is set at 650° C. to 900° C., and the reaction pressure of the reaction zone is set at -1 to 10 kPaG, so that the radioactive organic waste forms a mixed gas after reaction and cooling; S3, oxidation treatment stage: the temperature of the oxidation chamber is set to 850-1150°C, the residence time is at least 2s, the mixed gas first enters the oxidation chamber to obtain oxidized mixed gas, and the oxidized mixed gas enters the alkali washing quenching chamber and is quickly cooled to below 60-95°C to form flue gas; S4, tail gas treatment stage: the flue gas enters the tail gas treatment system for purification and then is discharged; S5, washing liquid drying stage: the washing liquid of the tail gas treatment system flows back to the alkali washing quenching chamber and flows to the washing liquid drying system together with the alkali washing liquid in the alkali washing quenching chamber for drying to form the first solid waste.

8. The method for treating radioactive organic waste according to claim 7, characterized in that: The waste feeding system includes a waste resin feeding system and a waste oil feeding system, the radioactive organic waste includes waste resin, waste activated carbon and waste oil, and step S1 preferably includes one of the following situations: (a) the radioactive organic waste includes waste resin, and the waste resin enters the waste resin feeding system; (b) the radioactive organic waste includes waste resin and waste oil, and the waste resin and the waste oil are fed together; (c) The radioactive organic waste includes waste resin and waste oil, the waste resin enters the waste resin feeding system, and the waste oil enters the waste oil feeding system; (d) The radioactive organic waste includes waste resin and waste activated carbon. After being mixed with water in the waste resin feeding system, the waste resin and the waste activated carbon enter the reforming reaction system in the form of slurry, wherein the mass ratio of the waste resin to the water is preferably 1:(1-2).

9. The method for treating radioactive organic waste according to claim 7, characterized in that: Step S2 further includes a gasifying agent, which is uniformly input into the lower part of the reaction zone through a gasifying agent inlet; wherein the gasifying agent is preferably air, oxygen and superheated water vapor; or, the gasifying agent is preferably air and superheated water vapor; or, the gasifying agent is preferably air; And / or, in step S2, the mixed gas is cooled using clean water and atomizing gas nitrogen; and / or, in step S2, the temperature of the air outlet of the cooling zone is lower than 600° C.; And / or, the fourth solid waste is discharged and packaged through the first waste particle discharge port, the second solid waste is discharged and packaged through the second waste particle discharge port, and the third solid waste is discharged and packaged through the third waste particle discharge port; wherein the particle size of the solid particles in the third solid waste is greater than 0.03 microns; wherein the solidified elements in the fourth solid waste, the second solid waste and the third solid waste preferably include potassium, sodium, calcium, lithium, cesium, strontium, cobalt, boron, sulfur and chlorine; and / or, the mixed gas includes one or more of nitrogen, methane, carbon monoxide, carbon dioxide, hydrogen and hydrogen sulfide; And / or, in step S2, the bed material used comprises alumina, wherein the particle size of the alumina is preferably 100-1000 microns; And / or, in step S2, an additive may also be used, wherein the additive is preferably clay-type kaolin, and the particle size of the clay-type kaolin is preferably 100-1000 microns.

10. The method for treating radioactive organic waste according to claim 7, characterized in that: In step S3, natural gas and air are introduced to fully oxidize and burn the mixed gas; and / or, the oxidized mixed gas includes carbon dioxide and water vapor; And / or, in step S3, the alkaline washing liquid used in the alkaline washing quenching chamber comprises sodium hydroxide; And / or, the flue gas includes nitrogen, carbon dioxide, acidic gas and nitrogen oxides; wherein the acidic gas is, for example, sulfur dioxide; wherein the volume percentage of the sulfur dioxide is preferably 5%-20%, and the volume percentage of the carbon dioxide is preferably 5%-30%; And / or, in step S4, the flue gas is sequentially desulfurized, denitrated, filtered and discharged; wherein the desulfurization method is preferably alkaline wet desulfurization, and the alkaline wet desulfurization is preferably direct mixed spray alkaline washing; the desulfurization agent used in the desulfurization preferably includes sodium hydroxide; wherein the temperature of the denitration is preferably 250-330°C; the denitration agent used in the denitration is preferably ammonia water; the denitration step is used to remove nitrogen oxides in the flue gas; wherein the filtration temperature is preferably 120-150°C; wherein the discharge temperature is preferably 100-140°C; and / or, the elements solidified in the first solid waste include potassium, sodium, calcium, lithium, cesium, strontium, cobalt, boron, sulfur and chlorine; And / or, the radioactive organic waste includes waste resin, waste activated carbon and waste oil, wherein the waste resin preferably includes anion exchange resin and / or cation exchange resin, wherein the chemical formula of the anion exchange resin is C 34 H 52 N3O3, the chemical formula of the cation exchange resin is C 25 H 25 The mass fraction of BO3 contained in the waste resin is preferably 2%-8%, and the total content of cesium, strontium and cobalt contained in the waste resin is preferably 0.2-100g / m 3 .

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