CN106732306A - The method of multicompartment fluidized bed steam reformer apparatus and treatment spent resin - Google Patents

Abstract

The invention provides a multilayer fluidized bed steam reforming equipment and a method for treating waste resin, which belong to the field of chemical industry. The steam reforming reaction equipment is a multi-layer fluidized bed reactor, and the fluidized bed reactor is divided into at least two independent beds by arranging a distribution plate and an overflow pipe in the fluidized bed reactor; waste resin, Catalysts, additives and mineralizers are added to the upper bed, cracking reaction and/or mineralization reaction and/or reduction reaction occurs, and mineralized particles and cracked gas are generated; carbonaceous substances are added to the lower bed to react and provide heat; the reaction generates The mineralized particles flow down through the overflow pipe under the action of gravity, and finally are discharged from the bottom of the fluidized bed reactor; the gas generated by the reaction is discharged from the top of the fluidized bed reactor. The invention can obtain products with large volume reduction ratio, high nuclide capture rate and good leaching resistance, and improves the controllability of the reaction process and the operation stability of the fluidized bed reactor.

Description

Multilayer fluidized bed steam reforming equipment and method for treating waste resin

technical field

The invention belongs to the field of chemical industry, and in particular relates to a multilayer fluidized bed steam reforming equipment and a method for treating waste resin.

Background technique

With the development of my country's nuclear technology, nuclear waste containing radioactivity will be produced in the process of nuclear power plant operation, nuclear fuel cycle, radioactive waste liquid treatment, nuclear facility decontamination and decommissioning, isotope production and application, and nuclear chemistry and radiochemistry experiments. , such as ion exchange resins, activated carbon, filter elements, waste organic solvents, labor protection supplies, etc. Among them, the radioactivity of waste resin accounts for about 80% of the total radioactivity of nuclear power waste. At present, my country's disposal of radioactive waste resin mainly adopts cement curing method, that is, using cement, mineral powder and other curing agents to directly solidify waste resin without special treatment, and then package and bury it. This method is low in cost and simple in operation, but it has the disadvantages of large waste volume increase, low nuclide anti-leaching performance, and small resin containment capacity, which cannot meet the growing demand for radioactive waste resin treatment and environmental protection requirements in China.

Fluidized bed steam reforming technology is a method in which waste resin undergoes complex reactions such as cracking and mineralization under high temperature conditions to produce mineral residues such as metal oxides or carbides, and then post-disposes the residues. Steam reforming technology can completely convert organic resins into inorganic substances, and enrich radioactive elements in mineralized substances. The resulting mineralized substances have good structural durability and stability, and high resistance to leaching of nuclides, which can achieve the purpose of safe capacity reduction. The method has a remarkable capacity reduction effect, and the waste volume can be reduced to 1/10-1/5 of that before treatment. Moreover, there will be no secondary pollution during the treatment process, and the synthetic gas produced after cracking can be converted into N ₂ , CO ₂ and water after treatment, basically no waste liquid is generated, and it is safe and pollution-free. Fluidized bed steam reforming technology has the advantages of lower reaction temperature than incineration, simpler tail gas treatment, more stable waste residue than vitrified body, and no liquid waste. It has been applied in the field of low-level radioactive waste treatment in foreign nuclear power plants. Has many years of history.

The fluidized bed steam reforming technology can be implemented in one fluidized bed reactor, and can also be implemented in multiple fluidized bed reactors connected in series, as described in US Pat. No. 6,084,147 and US Pat. In the fluidized bed steam reforming reactor, when the waste resin undergoes cracking and mineralization reactions, many different types of reactions such as carbonaceous material combustion reactions and reduction reactions will also occur. These reaction processes are coupled with each other. Once the fluidized bed reactor is not well controlled, it is easy to form local hot spots or produce viscous substances, resulting in agglomeration and agglomeration of fluidized particles, which will affect the fluidization quality and reaction effect in the slightest, and cause loss of flow in severe cases. parking. Therefore, there is an urgent need to develop new fluidized bed reactors and radioactive waste resin treatment methods to improve the operation stability of fluidized bed reactors and the treatment efficiency of waste resins.

Contents of the invention

The purpose of the present invention is to provide a method and equipment for processing waste resin using multi-layer fluidized bed steam reforming equipment, through decoupling of fluidized bed steam reforming reaction process and optimal control of reaction temperature and distribution thereof, Improve the operation stability and reaction efficiency of the fluidized bed reactor, and obtain solid products with high nuclide anti-leaching performance and large volume reduction ratio.

The invention provides a method for treating waste resins using multi-layer fluidized bed steam reforming equipment, comprising: using waste resins, carbonaceous substances, mineralizers, additives, and catalysts as raw materials, using steam and/or air and /or oxygen and/or nitrogen as fluidizing gas, in a fluidized bed reactor containing an inert bed and under high temperature conditions, the waste resin undergoes a cracking reaction to become small molecular organic matter and mineralization reaction to generate mineralization containing metal elements particles. Wherein, the steam reforming reaction equipment is a multilayer fluidized bed reactor, and the fluidized bed reactor is divided into at least two independent beds by arranging a distribution plate and an overflow pipe in the fluidized bed reactor; Resin, catalysts, additives and mineralizers are added to the upper bed, cracking reaction and/or mineralization reaction and/or reduction reaction occurs, and mineralized particles and cracked gas are generated; carbonaceous substances are added to the lower bed for heat supply; The mineralized particles generated by the reaction flow down through the overflow pipe under the action of gravity, and finally discharged from the bottom of the fluidized bed reactor; the gas generated by the reaction is discharged from the top of the fluidized bed reactor, and after the dust is removed by the filter, it is sent Incinerate in an incinerator, and then discharge gas or torch after alkali washing and drying. However, it should be pointed out that the subsequent gas treatment can be selected according to the actual working conditions and is not a limitation.

The carbonaceous material enters the first bed layer at the bottom of the multilayer fluidized bed reactor, and reacts with oxygen and/or water vapor in the first bed layer. The carbonaceous substance can also enter into other beds except the first bed, and act as a reducing agent in other beds.

C+O ₂ →CO ₂

C+ _H2O → _H2 +CO

CO+ _H2O → _CO2 + _H2

CO+O ₂ →CO ₂

H ₂ +O ₂ →H ₂ O

The waste resin, mineralizer, additive, catalyst and other raw materials enter other beds except the first bed, and cracking reaction and/or mineralization reaction and/or reduction reaction etc. occur in other beds to generate ore liquefied particles and pyrolysis gas. As a preferred method, the waste resin and the catalyst are added to the top several beds, and the additives and mineralizers are added to one or more layers between the layer where the waste resin is located and the layer where the carbonaceous material is located. The resin undergoes a cracking reaction to generate small molecule compounds and release radioactive elements, anions and cations, and the like.

C _x H _y O _z S _m →C+CH ₄ +CO+H ₂ +SO _n +etc

C _x H _y O _z N _m →C+CH ₄ +CO+H ₂ +NO _n +etc

Raw materials such as mineralizers and additives enter into other beds except the first bed, and mineralization reactions occur in other beds to form mineralized particles to complete the inclusion and adsorption of radioactive elements, anions and cations, etc.

2NaOH+Al ₂ O ₃ ·2SiO ₂ →2NaAlSiO ₄ +H ₂ O

8NaOH+2Cl ^- +3(Al ₂ O ₃ 2SiO ₂ )→Na ₆ Al ₆ Si ₆ O ₂₄ (2NaCl)+3H ₂ O+2OH ^-

The temperature control of the multilayer fluidized bed reactor is very important. If the temperature is too high, on the one hand, it will lead to the volatilization of radionuclides, resulting in poor containment effect and radioactive pollution; on the other hand, the metal salts generated by the reaction will melt and lead to agglomeration of fluidized particles, resulting in loss of flow in the fluidized bed reactor change. If the temperature is too low, the by-products of the cracking reaction will increase, which will also lead to coking and agglomeration. Since the mineralization reaction and cracking reaction are both endothermic reactions, the combustion reaction of carbonaceous substances is required to provide heat. A preferred temperature control scheme is that the temperature of each bed layer in the multilayer fluidized bed reactor is gradually reduced from bottom to top. Generally, the temperature of each bed is adjusted by adjusting the feed flow rate, feed temperature, and gas ratio of each bed. A preferred solution is to set at least one heat exchange device in each bed for controlling the temperature of the bed. The heat exchange device can remove heat from the bed, and can also input heat to the bed. The heat exchange medium can be selected from circulating water commonly used in industrial installations, steam of different pressure levels, gas of different temperatures, molten salt, etc. Common heating means such as electric heating may also be used.

The pressure control of the multilayer fluidized bed reactor is also very important, and it can be operated under negative pressure conditions, or under normal pressure or high pressure conditions. The recommended pressure range is 0.001-10 MPaA, preferably 0.01-1 MPaA, more preferably 0.09-0.1 MPaA. Operating under negative pressure conditions can avoid the leakage of radionuclides and improve the safety of the system.

Said fluidizing gas consists of nitrogen and/or oxygen and/or water vapor and/or CO and/or _CO2 and/or _H2 . The fluidization gas at least enters the first lowermost bed layer of the multilayer fluidized bed reactor. A preferred way of gas intake is that part of the fluidization gas enters the first bed, and part of the fluidization gas enters other beds. The flow rate and composition of the fluidized gas entering each bed are determined according to the reaction requirements and temperature control requirements.

The multi-layer fluidized bed reactor is filled with inert particles, which only serve as fluidizing medium and do not participate in chemical reactions. A preferred embodiment is that each bed contains inert particles. Another preferred embodiment is that except the first bed, all other beds are filled with inert particles.

The residence time of the waste resin and mineralized particles in the reactor needs to be strictly controlled. If the residence time is too short, the reaction cannot be fully carried out; if the residence time is too long, the efficiency of the reactor is too low. The residence time of waste resin and mineralized particles is 1 s-10 hr, preferably 10 s-2 hr, more preferably 1 min-30 min.

The present invention also provides a preferred method of using the preferred structure of the multi-layer fluidized bed steam reforming reactor to dispose of waste resin, characterized in that: the multi-layer fluidized bed is divided into three beds, from From top to bottom are the third bed, the second bed, and the first bed. Wherein, the temperature of the first bed is 750-1000°C, the temperature of the second bed is 500-750°C, and the temperature of the third bed is 200-500°C. The waste resin and catalyst are added to the third bed, and the functional group removal reaction takes place in the third bed, and the solid product enters the second bed through the overflow pipe; The skeleton cracks and releases radionuclides, anions and cations, etc.; the mineralizers, additives, etc. are added to the second bed layer, and mineralization reactions occur in the second bed layer, and the radionuclides and anions and cations are mineralized During the reaction, solid particles are wrapped by mineralized products, and the mineralized particles enter the first bed through the overflow pipe; the carbon-containing substances are added to the first bed, and in the first bed, the carbon-containing substances are mixed with water vapor, Oxygen and other reactions. At least one heat exchange device is respectively arranged in each bed layer to control the temperature of the bed layer. The temperature of the third bed is controlled by adjusting the temperature of the steam entering the third bed, the amount of carbon powder that can participate in the oxidation reaction and/or the flow rate of oxygen and/or the heat exchange capacity of the heat exchange device; the temperature of the second bed is controlled by Adjust the feed flow rate and/or feed temperature and/or the heat exchange capacity of the heat exchange device and/or control the amount of carbon powder involved in the oxidation reaction; the temperature of the first bed is controlled by adjusting the amount of carbon powder entering the third bed and/or Or oxygen flow and/or water vapor flow and/or heat exchange capacity control of heat exchange device.

The present invention also provides a multi-layer fluidized bed reactor used in the waste resin treatment method, comprising a fluidized bed reactor tower body and a gas distribution plate and an overflow pipe arranged in the tower body: in the tower body, From the bottom of the tower to the top of the tower, it can be divided into a first chamber and a second chamber with the gas distribution plate as the boundary. The first chamber and the second chamber pass through the gas distribution plate and are arranged in the The overflow pipe on the gas distribution plate is connected. By setting the gas distribution plate in the tower body of the fluidized bed reactor, the fluidized gas entering the second bed layer between the top of the tower and the gas distribution plate reacts with the reactants, and the first gas product produced is produced by the gas at the top of the tower. The top opening is discharged, and the first solid product enters the first bed between the gas distribution plate and the bottom of the tower through the overflow pipe, and contacts and reacts with the fluidizing gas; the carbonaceous substance added in the first bed reacts with the fluidizing gas Gas is generated, and the first solid product will also react to generate part of the gas. The generated second gas product enters the second bed layer, and the second solid product enters the bottom of the tower and is recovered from the bottom opening. In this way it is possible to divide the chamber between the top and the bottom of the column into at least two zones of different temperatures by making the reaction temperature of the first bed higher than the reaction temperature of the second bed and recovering a second solid The product can obtain a solid product with high nuclide resistance to leaching and a large volume reduction ratio.

The present invention also provides another multi-layer fluidized bed reactor used in the waste resin treatment method, comprising a fluidized bed reactor tower body and a first gas distribution plate and a second gas distribution plate arranged in the tower body And partition: in the tower body, from the bottom of the tower to the top of the tower, it can be divided into a first chamber and a second chamber bounded by the partition, the second gas distribution plate and the first gas distribution plate , the third chamber, the fourth chamber; the first chamber and the second chamber are separated by a partition, and the first chamber communicates with the third chamber through an overflow pipe arranged on the second gas distribution plate , the second chamber communicates with the third chamber through the second gas distribution plate, and the third chamber and the fourth chamber communicate through the first gas distribution plate and the overflow pipe arranged on the first gas distribution plate connected.

Although the above only provides the forms of two-layer and three-layer fluidized beds, in fact, more beds can also be set in the tower body of the fluidized bed reactor.

The present invention has the following characteristics: the oxidation reaction, reduction reaction, cracking reaction and mineralization reaction are placed in different bed layers to complete, avoiding the mutual influence between each reaction, and greatly improving the controllability of the reaction process; The temperature distribution and product distribution of the bed can avoid particle agglomeration and agglomeration, and greatly improve the operation stability of the fluidized bed reactor; products with large volume reduction ratio, high radionuclide capture rate and high nuclide resistance to leaching can be obtained.

Description of drawings

Fig. 1 is a schematic structural view of a multi-layer fluidized bed steam reforming reactor provided by the present invention.

Fig. 2 is a structural schematic diagram of another multi-layer fluidized bed steam reforming reactor provided by the present invention.

detailed description

The multi-layer fluidized bed steam reforming equipment and the method for treating waste resin provided by the present invention will be described in detail below with reference to FIG. 1 and FIG. 2 .

As shown in Figure 1, the multilayer fluidized bed steam reforming equipment according to the present invention includes a fluidized bed reactor tower body 1 and a gas distribution plate 2 and an overflow pipe 3 arranged in the tower body 1, wherein, in the tower body Inside the body 1, from the bottom of the tower to the top of the tower, the gas distribution plate 2 can be divided into a first chamber and a second chamber, and the first chamber and the second chamber are distributed through the gas The plate 2 communicates with the overflow pipe 3 provided on the gas distribution plate 2 . A first opening 6, a second opening 7 and a fourth opening 9 are provided on the side wall of the tower body 1 of the second chamber, and a first opening 6, a second opening 7, and a fourth opening 9 are arranged on the side wall of the tower body 1 of the second chamber. Three openings 8 , fifth opening 10 and sixth opening 11 . A gas outlet 4 is also arranged at the top of the tower body, and a solid outlet 5 is arranged at the bottom of the tower body.

As shown in Fig. 2, a kind of preferred multilayer fluidized bed steam reforming equipment according to the present invention comprises: the first gas distribution plate 2 that is arranged in tower body 1, the second gas distribution plate 15, dividing plate 17, The first overflow pipe 3 and the second overflow pipe 16 . Wherein, from the bottom of the tower body 1 to the top of the tower, with the partition plate 17, the second gas distribution plate 15, and the first gas distribution plate 2 as boundaries, it can be divided into a first chamber, a second chamber, and a second chamber. Three chambers, the fourth chamber; the first chamber and the second chamber are separated by a partition 17, and the first chamber and the third chamber are separated by the second overflow provided on the second gas distribution plate 15 The pipe 16 communicates, the second chamber communicates with the third chamber through the second gas distribution plate 15, the third chamber and the fourth chamber pass through the first gas distribution plate 2 and are arranged on the first gas distribution plate The upper first overflow pipe 3 communicates. The seventh opening 12, the eighth opening 13 and the ninth opening 14 are arranged on the side wall of the tower body 1 of the second chamber, and the first opening 12 is arranged on the side wall of the tower body 1 of the third chamber. Two openings 7 , a third opening 8 , a fifth opening 10 and a sixth opening 11 , the first opening 6 and the fourth opening 9 are provided on the side wall of the tower body 1 of the fourth chamber. A gas outlet 4 is also arranged at the top of the tower body, and a solid outlet 5 is arranged at the bottom of the tower body.

As shown in Figure 2, in the described multi-layer fluidized bed steam reforming reactor tower body 1, the diameter of the tower body between the top of the tower body and the partition plate 17 is greater than that from the bottom of the tower body to the partition plate 17 Between the diameter of the tower body, the ratio is 1:(0.3～1.0). Both the first gas distribution plate 2 and the second gas distribution plate 15 in the tower body 1 are provided with small holes, the diameter of which is 0.1-5mm, and the opening ratio is 1%-5%. A preferred solution is to use a side hole type gas distribution plate and install a wind cap above the vent hole. Known hood structures can be used. The preferred hood structure is that the top of the hood is conical, and its inclination angle is greater than the material accumulation angle.

The vertical distance a from the top of the tower body 1 to the first opening 6, the vertical distance b from the top of the tower body 1 to the second opening 7, the vertical distance b from the top of the tower body 1 to the third opening 8, the vertical distance c from the top of the tower body 1 to the fourth opening 9, the vertical distance e from the top of the tower body 1 to the fifth opening 10, and the vertical distance e from the top of the tower body 1 to the fourth opening 9. The vertical distance f of the sixth opening 11, the vertical distance g from the top of the tower body 1 to the seventh opening 12, the vertical distance h from the top of the tower body 1 to the eighth opening 13, the vertical distance h of the tower body 1 The vertical distance i from the top of the tower to the ninth opening 14 preferably satisfies: a:b:c:d:e:f:g:h:i=1:(2～4):(2～5): (1～1.5):(2～3):(2～4):(6～8):(6～9):(8～10). The volume ratio of the fourth chamber, the third chamber, the second chamber and the first chamber is 1:(1-1.6):(1-1.7):(0.4-1).

Satisfy between the vertical distance A from the top of the tower body 1 to the mouth of the overflow pipe 3, the vertical distance B from the top of the tower body 1 to the first gas distribution plate 2: A:B= 1: (1～1.5), the vertical distance C between the tower top of the tower body 1 and the lower nozzle of the overflow pipe 3, and the vertical distance D between the tower top of the tower body 1 and the second gas distribution plate 15 Satisfy: C:D=1:(1～1.3); the vertical distance a from the tower top of the tower body 1 to the mouth of the overflow pipe 16, the tower top of the tower body 1 to the second gas distribution plate 15 Satisfy between the vertical distance b of: a:b=1:(1～1.3), the vertical distance c from the top of the tower body 1 to the dividing plate 17, the tower top of the tower body 1 to the overflow pipe 16 The vertical distance d between the lower nozzles satisfies: c:d=1:(1～1.2).

The present invention also provides a method of using multi-layer fluidized bed steam reforming equipment to process waste resins, the method comprising waste resins, carbonaceous substances, mineralizers, additives, catalysts as raw materials, steam and/or Air and/or Oxygen and/or Nitrogen and/or CO and/or _CO2 and/or _H2 as fluidizing gas for pyrolysis of waste resin in a fluidized bed reactor with a bed of inert particles and under high temperature conditions The reaction turns into small molecular organic matter and releases radioactive elements. At the same time, a mineralization reaction occurs to generate mineralized particles containing anions, cations and radioactive elements. Carbon-containing substances react with oxygen and/or water vapor to provide heat. Wherein, the steam reforming reaction equipment is a multilayer fluidized bed reactor, and the fluidized bed reactor is divided into at least two independent beds by arranging a distribution plate and an overflow pipe in the fluidized bed reactor; Resin, catalysts, additives and mineralizers are added to the upper bed, cracking reaction and/or mineralization reaction and/or reduction reaction occurs, and mineralized particles and cracked gas are generated; carbonaceous substances are added to the lower bed for heat supply; The mineralized particles generated by the reaction flow down through the overflow pipe under the action of gravity, and finally discharged from the bottom of the fluidized bed reactor; the gas generated by the reaction is discharged from the top of the fluidized bed reactor, and after the dust is removed by the filter, it is sent Incinerate in an incinerator, and then discharge gas or torch after alkali washing and drying.

According to the method provided by the present invention, a preferred scheme is that the carbonaceous material enters the first bed layer at the bottom of the multilayer fluidized bed reactor, and reacts with oxygen and/or water vapor in the first bed layer . The carbonaceous substance can also enter into other beds except the first bed, and act as a reducing agent in other beds. The waste resins, catalysts and other raw materials enter other beds except the first bed, where cracking reactions occur to generate small molecular compounds and release radioactive elements, anions and cations, etc. Raw materials such as mineralizers and additives enter into other beds except the first bed, and mineralization reactions occur in other beds to form mineralized particles to complete the inclusion and adsorption of radioactive elements, anions and cations, etc. A preferred scheme is that the waste resin and the catalyst are added to the top several beds, and the additives and mineralizers are added to one or more layers between the layer where the waste resin is located and the layer where the carbonaceous material is located.

According to the method provided by the present invention, the temperature control of the multilayer fluidized bed reactor is very important. If the temperature is too high, on the one hand, it will lead to the volatilization of radionuclides, resulting in poor containment effect and radioactive pollution; on the other hand, the metal salts generated by the reaction will melt and lead to agglomeration of fluidized particles, resulting in loss of flow in the fluidized bed reactor change. If the temperature is too low, the by-products of the cracking reaction will increase, which will also lead to coking and agglomeration. Since the mineralization reaction and cracking reaction are both endothermic reactions, the combustion reaction of carbonaceous substances is required to provide heat. In the multi-layer fluidized bed reactor, the temperature of each bed layer decreases gradually from bottom to top. Generally, the temperature of each bed is adjusted by adjusting the feed flow rate, feed temperature, and gas ratio of each bed. A preferred solution is to set at least one heat exchange device in each bed for controlling the temperature of the bed. The heat exchange device can remove heat from the bed, and can also input heat to the bed. The heat exchange medium can be selected from circulating water commonly used in industrial installations, steam of different pressure levels, gas of different temperatures, molten salt, etc. Common heating means such as electric heating may also be used.

According to the method provided by the present invention, the pressure control of the multilayer fluidized bed reactor is also very important, and it can be operated under negative pressure conditions, or under normal pressure or high pressure conditions. The recommended pressure range is 0.001-10 MPaA, preferably 0.01-1 MPaA, more preferably 0.09-0.1 MPaA. Operating under negative pressure conditions can avoid the leakage of radionuclides and improve the safety of the system.

In the present invention, the fluidization gas at least enters the first lowermost bed layer of the multilayer fluidized bed reactor. A preferred way of gas intake is that part of the fluidization gas enters the first bed, and part of the fluidization gas enters other beds. The flow rate and composition of the fluidized gas entering each bed are determined according to the reaction requirements and temperature control requirements.

In the present invention, the multi-layer fluidized bed reactor is filled with inert particles, which only serve as fluidizing medium and do not participate in chemical reactions. A preferred embodiment is that each bed contains inert particles. Another preferred embodiment is that except the first bed, all other beds are filled with inert particles.

In the present invention, the residence time of the waste resin and mineralized particles in the reactor needs to be strictly controlled. If the residence time is too short, the reaction cannot be fully carried out; if the residence time is too long, the efficiency of the reactor is too low. The residence time of waste resin and mineralized particles is 1 s-10 hr, preferably 10 s-2 hr, more preferably 1 min-30 min.

The present invention also provides a method for treating waste resin using the preferred structure of the multi-layer fluidized bed steam reforming reactor, characterized in that: the multi-layer fluidized bed is divided into three beds, from top to bottom The bottom is the third bed, the second bed, and the first bed. Wherein, the waste resin and the catalyst are added to the third bed, and the functional group removal reaction occurs in the third bed, and the product enters the second bed through the overflow pipe; The skeleton cracking reaction and release radionuclides, anions and cations, etc.; the mineralizers, additives, etc. are added to the second bed layer, and mineralization reactions occur in the second bed layer, radionuclides and anions and cations in the mineral In the chemical reaction, solid particles are wrapped by mineralized products, and the mineralized particles enter the first bed through the overflow pipe; the carbon-containing substances are added to the first bed, and the carbon-containing substances and water vapor in the first bed , oxygen and other reactions. At least one heat exchange device is respectively arranged in each bed layer to control the temperature of the bed layer. The temperature of the third bed is controlled by adjusting the temperature of the steam entering the third bed, the amount of carbon powder that can participate in the oxidation reaction and/or the flow rate of oxygen and/or the heat exchange capacity of the heat exchange device; the temperature of the second bed is controlled by Adjust the feed flow and/or feed temperature and/or heat exchange capacity control of the heat exchange device; the temperature of the first bed is controlled by adjusting the amount of carbon powder entering the third bed and/or oxygen flow and/or steam flow and /or control the heat exchange capacity of the heat exchange device.

In the present invention, the feed of the waste resin, mineralizer and carbonaceous material includes but not limited to slurry liquid state, solid state, liquid state, gas entrainment and other forms; the inert bed medium includes but not limited to alumina, white cloud Stone, sintered bauxite, nepheline, sintered calcium silicate and other substances; said mineralizers include but not limited to kaolin, montmorillonite, illite clay and other substances; said carbonaceous substances include but not limited to charcoal, Coke, coal powder, sugar and other reducing substances. The catalyst includes but not limited to calcium oxide, magnesium oxide, aluminum sulfate, iron, ferric sulfate, ferric nitrate and other substances; the additive includes but not limited to sodium chloride, sodium hydroxide, sodium sulfate and other substances.

According to the fluidized bed steam reforming equipment and waste resin disposal method of the present invention, by setting the first gas distribution plate and the second gas distribution plate in the fluidized bed reactor tower body, the gas entering the top of the tower and the first gas distribution The fluidization gas in the third bed between the plates reacts with the reactants, and the first gas product produced is discharged from the top opening of the tower top, and the first solid product enters the first distribution plate and the second gas distribution plate through the overflow pipe. The second bed layer between the gas distribution plates contacts and reacts with the fluidization gas, and the second gas product produced enters the third bed layer, and the second solid product enters the bottom of the tower through the overflow pipe and is recovered from the bottom opening. In this way it is possible to divide the chamber between the top and the bottom of the column into at least two zones of different temperatures by making the reaction temperature of the second bed higher than the reaction temperature of the third bed and recovering the second solid Products, so as to obtain solid products with high nuclide anti-leaching performance and large volume reduction ratio.

The present invention will be further described below through embodiment.

Example 1

This example is used to illustrate the multi-layer fluidized bed steam reforming equipment and the method for treating waste resin provided by the present invention.

Adopt multi-layer fluidized bed steam reforming equipment as shown in Figure 2 to process waste resin, this fluidized bed steam reforming equipment comprises a fluidized bed reactor tower body 1, the inner diameter of the tower is 0.5m, and the height of the tower body is 7m, A first gas distribution plate 2, a second gas distribution plate 15, and a dividing plate 17 are arranged successively from the top of the tower to the bottom of the tower. The diameter of the openings on the gas distribution plate 15 is 0.8 mm, and the opening ratio is 2%. From the bottom of the tower body 1 to the top of the tower, the dividing plate 17, the second gas distribution plate 15, and the first gas distribution plate 2 are bounded by the first chamber, the second chamber, the third chamber and The fourth chamber; the seventh opening 12, the eighth opening 13 and the ninth opening 14 are arranged on the side wall of the tower body 1 of the second chamber, and the side wall of the tower body 1 of the third chamber The second opening 7, the third opening 8, the fifth opening 10 and the sixth opening 11 are arranged on the wall, and the first opening 6 and the fourth opening 9 are arranged on the side wall of the tower body 1 of the fourth chamber. , a top opening 4 is provided at the top of the tower body 1 , and a bottom opening 5 is provided at the bottom of the tower body 1 . The first chamber and the second chamber are isolated by a partition 17, the first chamber communicates with the third chamber through the overflow pipe 16 arranged on the second gas distribution plate 15, and the second chamber communicates with the third chamber. The chambers communicate through the second gas distribution plate 15, and the third chamber and the fourth chamber communicate through the first gas distribution plate 2 and the overflow pipe 3 disposed on the first gas distribution plate. The inner diameter of the overflow pipe 3 is 0.08m, and the inner diameter of the overflow pipe 16 is 0.08m. The ratio of the tower body diameter between the top of the tower body 1 to the partition 17 and the tower bottom to the tower body diameter between the partition 17 is 1:0.5, and the tower top of the tower body 1 to the first partition The vertical distance a of an opening 6, the vertical distance b from the top of the tower body 1 to the second opening 7, the vertical distance c from the top of the tower body 1 to the third opening 8, the top of the tower body 1 The vertical distance d to the fourth opening 9, the vertical distance e from the top of the tower body 1 to the fifth opening 10, the vertical distance f from the top of the tower body 1 to the sixth opening 11, the tower body The vertical distance g from the top of the tower body 1 to the seventh opening 12, the vertical distance h from the top of the tower body 1 to the eighth opening 13, the vertical distance from the top of the tower body 1 to the ninth opening 14 Satisfy between i: a:b:c:d:e:f:g:h:i=1:2:3:1:3:3:6:7:9, the fourth chamber, the third The volume ratio of the chamber, the second chamber and the first chamber is 1:1.3:1.5:0.7, the vertical distance A from the top of the tower body 1 to the mouth of the overflow pipe 3, the tower body 1 The vertical distance B from the top to the first gas distribution plate 2 satisfies: A:B=1:1.2, the vertical distance C from the tower top of the tower body 1 to the lower nozzle of the overflow pipe 3, the tower body 1 Satisfy between the vertical distance D from the top of the tower to the second gas distribution plate 15: C:D=1:1.2; the vertical distance a from the top of the tower body 1 to the mouth of the overflow pipe 16, the tower The vertical distance b between the top of the tower body 1 and the second gas distribution plate 15 satisfies: a:b=1:1.1, the vertical distance c from the top of the tower body 1 to the partition plate 17, the vertical distance c of the tower body 1 The vertical distance d between the top of the tower and the lower nozzle of the overflow pipe 16 satisfies: c:d=1:1.05.

Using the method for treating radioactive waste resin of the present invention, the inert fluidized medium is respectively loaded into the third bed and the second bed, and the filling height is 1.5 times of the inner diameter of the fluidized bed. The slurry liquid reactant containing waste resin (the contents of Cs and Co are respectively: 0.1g/kg resin, the cation exchange resin is Amberlite IRN-77, and the anion exchange resin is Amberlite IRN-78) is introduced through the first opening In the third bed layer, the catalyst is passed into the third bed layer through the fourth opening, carbonaceous substances such as charcoal are passed into the second bed layer and the first bed layer through the third opening and the seventh opening, and kaolin is passed into the second bed layer through the second opening In the second bed, oxygen passes into the second bed and the first bed through the sixth opening and the ninth opening respectively, and water vapor passes into the second bed and the first bed through the fifth opening and the eighth opening respectively. Wherein, the feeding mass ratio of mineralizer kaolin and waste resin is 2:1, the feeding mass ratio of mineralizing agent kaolin and additive sodium hydroxide is 1.7:1, and the feeding mass ratio of catalyst iron and waste resin is 0.05:1, The feeding mass ratio of oxygen and carbonaceous substances is 2:1. The temperature of the three beds is controlled by adjusting the flow rate of carbonaceous material, oxygen flow rate and inlet steam temperature. In the third bed, the fluidized gas that waste resin enters into the third bed through the gas distribution plate is in fluidized contact with the inert fluidized medium, and the functional group cracking reaction occurs. The reaction temperature is 350°C, the pressure is 68KPaA, and the reaction time is After 2 minutes, the solid product produced flows into the second bed layer through the overflow pipe, and the gas is discharged from the outlet at the top of the tower. In the second bed, the solid product and mineralizer flowing into the third bed pass through the gas distribution plate, and the fluidizing gas entering the second bed is fluidized and contacted with the inert fluidized medium, and the skeleton cracks to release nuclides. Simultaneously, the mineralization reaction captures nuclides to form mineralized particles, the reaction temperature is 725°C, the pressure is 84KPaA, and the reaction time is 5 minutes. In the first bed layer, the carbonaceous substance passed in reacts with oxygen to release heat, such as combustion. The reaction temperature is 900°C and the pressure is 100KPaA.

The volume test, nuclide concentration test and nuclide anti-leaching test of the solid product obtained in the above reaction process showed that compared with the feed reactant, the volume reduction of the product was 1/9 of the reactant, and the nuclide wrapping efficiency reached 99.99%, nuclide anti-leaching efficiency of 99.9%. During the three-month test period, there was no shutdown caused by agglomeration and agglomeration of the device.

Example 2

This example is used to illustrate the multi-layer fluidized bed steam reforming equipment and the method for treating radioactive waste resin provided by the present invention.

Using the same multilayer fluidized bed steam reforming equipment as in Example 1 to process waste resins, the process includes: packing the inert fluidized medium into the third bed and the second bed respectively, and the filling height is the inner diameter of the fluidized bed 1.5 times. The slurry liquid reactant containing waste resin (the contents of Cs and Co are respectively: 0.1g/kg resin, the cation exchange resin is Amberlite IRN-77, and the anion exchange resin is Amberlite IRN-78) is introduced through the first opening In the third bed, the catalyst is passed into the third bed through the fourth opening, carbonaceous substances such as charcoal are passed into the second bed and the first bed through the third opening and the seventh opening, and the mineralizer is passed through the second opening Pass into the second bed, the oxygen enters the second bed and the first bed through the sixth opening and the ninth opening respectively, and the steam enters the second bed and the first bed through the fifth opening and the eighth opening respectively . Wherein, the feeding mass ratio of mineralizer kaolin and waste resin is 2:1, the feeding mass ratio of mineralizing agent kaolin and additive sodium hydroxide is 1.7:1, and the feeding mass ratio of catalyst iron and waste resin is 0.05:1, The feeding mass ratio of oxygen and carbonaceous substances is 2:1. The temperature of the three beds is controlled by adjusting the flow rate of carbonaceous material, oxygen flow rate and inlet steam temperature. In the third bed, the fluidized gas that waste resin enters the third bed through the gas distribution plate is in fluidized contact with the inert fluidized medium, and the functional group cracking occurs. The reaction temperature is 300°C, the pressure is 65KPaA, and the reaction time is 30. Seconds, the solid product produced flows into the second bed through the overflow pipe, and the gas is discharged from the outlet at the top of the tower. In the second bed, the solid product and mineralizer flowing into the third bed pass through the gas distribution plate, and the fluidizing gas entering the second bed is fluidized and contacted with the inert fluidized medium, and the skeleton cracks to release nuclides. Simultaneously, the mineralization reaction captures the nuclide to form mineralized particles. The reaction temperature is 600°C, the pressure is 85KPaA, and the reaction time is 2 minutes. In the first bed layer, the carbonaceous substance passed in reacts with oxygen to release heat, such as combustion. The reaction temperature is 900°C and the pressure is 101KPaA.

The solid product obtained in the above reaction process was subjected to volume test, nuclide concentration test and nuclide anti-leaching test. The results showed that compared with the feed reactant, the volume reduction of the product was 1/8 of the reactant, and the nuclide encapsulation efficiency reached 99.87%, nuclide anti-leaching efficiency of 99.5%. During the three-month test period, there was no shutdown caused by agglomeration and agglomeration of the device. Comparing the two examples, the temperature of the second bed in Example 2 is lower than that of Example 1, the cracking of the resin skeleton is not complete and the release of nuclide is not complete, and the insufficient heat absorption of the mineralization reaction leads to relatively low stability of the product particle structure, resulting in product loss. The volume ratio decreases, the nuclide encapsulation efficiency and anti-leaching efficiency decrease, which is consistent with the test results.

Example 3

The device used in this embodiment is the same as the previous example, the difference is that the mass ratio of mineralizer montmorillonite and waste resin in the device is 1.5:1, and the mass ratio of mineralizer montmorillonite and additive sodium chloride is 0.8:1, the feeding mass ratio of catalyst iron sulfate and waste resin is 0.07:1, and the feeding mass ratio of oxygen and carbonaceous substances is 3:1. The obtained solid product is tested, and its effect is basically the same as that of Example 2.

Example 4

The device used in this embodiment is the same as the previous example, the difference is that the mass ratio of mineralizer illite and waste resin in the device is 1:1, the mass ratio of mineralizer illite to additive sodium sulfate is 1:1, and the catalyst The feeding mass ratio of magnesium oxide and waste resin is 0.02:1, and the feeding mass ratio of oxygen and carbonaceous substances is 3:2. The obtained solid product is tested, and its effect is basically the same as that of Example 2.

The above-mentioned embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. Various changes and modifications can be made by those skilled in the relevant technical fields without departing from the spirit and scope of the present invention. Therefore, all technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims (10)

1. a kind of method that use multicompartment fluidized bed steam reformer apparatus process spent resin, it is characterised in that：Described steam weight Whole consersion unit is multicompartment fluidized bed reactor, by setting distribution grid and overflow pipe in a fluidized bed reactor, by fluid bed Reactor is divided at least two independent beds；Spent resin, catalyst, additive and mineralizer are added into top bed, is occurred Cracking reaction and/or mineralising reaction and/or reduction reaction, generate mineralized particles and cracking gas；Added in the bed of lower section carbon containing Substance reaction heat supply；The mineralized particles for reacting generation flow downward through overflow pipe under gravity, finally anti-from fluid bed Device bottom is answered to discharge；The gas for reacting generation is discharged from fluidized-bed reactor top.

2. it is according to claim 1 treatment spent resin method, it is characterised in that：Described carbonaceous material enters many laminar flows First bed of fluidized bed reactor bottom, reacts in the first bed with oxygen and/or water vapour.

3. it is according to claim 1 treatment spent resin method, it is characterised in that：Described spent resin and catalyst are added Some beds of the top, by additive and mineralizer add layer where spent resin and carbonaceous material between layers one layer or In multilayer.

4. according to the method for any described treatment spent resins of claim 1-3, it is characterised in that：Described multicompartment fluidized bed is anti- Answer in device that the temperature of each bed is gradually reduced from bottom to up.

5. according to the method for any described treatment spent resins of claim 1-3, it is characterised in that：Fluidized gas at least enter multilayer First bed of fluidized-bed reactor bottom.

6. according to the method for any described treatment spent resins of claim 1-3, it is characterised in that：The multicompartment fluidized bed is divided into Three beds, are followed successively by the 3rd bed, the second bed, the first bed from top to bottom；Wherein, the temperature of the first bed be 750~ 1000 DEG C, the temperature of the second bed is 500~750 DEG C, and the temperature of the 3rd bed is 200~500 DEG C.

7. it is according to claim 6 treatment spent resin method, it is characterised in that：The spent resin and catalyst add the , there is functional group's elimination reaction in three beds, the skeleton that spent resin occurs in second bed splits in the 3rd bed Solution reaction；The mineralizer and additive add the second bed, mineralising reaction occurs in second bed and completes to the moon The absorption of cation, radioactive element, generates mineralized particles；The carbonaceous material adds the first bed, in first bed Middle carbonaceous material and water vapour and/or oxygen reaction.

8. according to the method for any described treatment spent resins of claim 1-7, it is characterised in that：Set respectively in each bed At least one heat-exchanger rig is put, for controlling bed temperature.

9. a kind of multicompartment fluidized bed steam reformer apparatus for realizing claim 1 methods described, including fluidized-bed reactor tower body And it is arranged on gas distribution grid and overflow pipe in tower body, it is characterised in that：In tower body, from the bottom of towe of the tower body to tower Top, first chamber, second chamber are at least divided into as boundary with the gas distribution grid, and first chamber is with second chamber by gas point Fabric swatch and the overflow pipe connection being arranged on the gas distribution grid.

10. multicompartment fluidized bed steam reformer apparatus according to claim 9, it is characterised in that：Including fluidized-bed reactor Tower body and the first gas distribution grid being arranged in tower body, second gas distribution grid and dividing plate, in tower body, from the tower The bottom of towe of body is divided into first chamber, with the dividing plate, second gas distribution grid, first gas distribution grid as boundary successively to tower top Two chambers, the 3rd chamber, the 4th chamber；First chamber and second chamber are isolated by dividing plate, and first chamber is led to the 3rd chamber The overflow pipe connection being arranged on the second gas distribution grid is crossed, second chamber passes through second gas distribution grid with the 3rd chamber Connection, the 3rd chamber and the 4th chamber are by setting the first gas distribution grid and being arranged on the first gas distribution grid Overflow pipe is connected.