TWI224024B - System and method for purifying and reutilizing boricacid solution of high concentration with reverse osmosis membrane - Google Patents

Abstract

A system and method for purifying and reutilizing boric acid solution of high concentration containing low concentration impurity such as silica with high-efficiency thin-film polyamide reverse osmosis membrane as separating media are disclosed. This system and method could apply to the main cooling system of nuclear power plant with pressurized water reactors. The system includes a boric acid storing device, a concentrate-storing device, a reserve osmosis separating device, an electric control system and a boric acid and silicon dioxide detecting device. By virtue of connecting the above devices and following the specific manipulating steps, the goal of high-efficiently purifying and reutilizing boric acid can be reached.

Description

1224024 V. Description of the invention (1), the technical field to which the invention belongs The present invention relates to a system and method for processing a high-concentration boric acid solution with or without radioactivity by using a reverse osmosis film, in particular to use a thin-film polyamine (thin- (film p〇iyamide) reverse osmosis (Reverse osmoxisis) membrane to separate boric acid and silicon dioxide in boric acid solution, and a system and method for purifying and reusing boric acid, which can be applied to the main cooling system of pressurized water nuclear power plants. High-concentration side acid solution 'and other chemical industry operations. 2. In the prior art, the high concentration of radioactivity in the main cooling system, "Solution cooling? = Reactivity control agent, due to the degree of main = during operation." Therefore, boron must be removed from the main cooling water; = system silicon is removed and reduced to an acceptable level. S ^-acid water 3 each: pressurized water nuclear power plant for butterfly water containing high concentration of dioxide Luoye has traditionally been treated in two ways, two: cutting liquid treatment, radioactive waste treatment fee ^ waste, the other is directly discharged to the outside :::: The two methods do not go through the country, China (China The Republic of China's environmental protection regulations are restricted. To use this field for water treatment, special treatment procedures must be performed to reduce the amount of boric acid to be treated. Fantastic principles are traditionally used in the semiconductor industry. Due to the existence of silicon dioxide, it is achieved by: boron stop and chemical conversion; this application is based on hydrazone and reverse osmosis membrane.

Page 7 1224024 Five 'invention description (2) Boric acid (H3B03) is very weak: acid, complex 9.2. The sulphur dioxide (Si⑻ is a representative 代表 = heng = (PKa) value is (H4Si04) exists, tDKa # R is pre-formed, in the water as silicic acid ^ (B (〇H) 4-), -STiTJ 'Only when the pH is> 10, the acid storage tank 删 <7) will be deleted from the fossil acid salt (_. 1-4) in the nuclear power plant, and the boron will be the resin Ϊ.I method; ；: ^ t Existing anthracite exists; while the traditional anion • has the ability to separate 3 negatively charged borate and silicate, the ion exchange method of boronic acid and silicon dioxide has no effect on the separation of boronic acid and silicon dioxide; the efficiency of recycling butterfly acid is low , Does not meet economic and practical value. The method of treating pressurized main cooling water and recovering boric acid was initially prepared in advance. The method of shrinking wood was first used, but the concentrated high-concentration shed acid would crystallize, and a would also contain radioactive salt deposits. Method For the volatility of steam, the acidity needs to be controlled to avoid crystallization, which makes the method very complicated. This method is no longer used. The ion-exchange resin is used to directly concentrate the shed acid. The main cooling water ρ η is in the test 11 (ρ Η-9 · 5 ) Can separate borate and silicate, but because their pKa is very close, good separation effect cannot be obtained, which is not conducive to practicality and economy. Therefore, the use of reverse osmosis separation method is the most feasible method. In the traditional technology, in the case of pressurized water nuclear power plants using reverse osmosis membranes to remove oxidized oxidant and to recover butterfly acid, cellulose acetate (CA) hollow fiber membranes are mostly used. USF cology applied this traditional technique to the United States 2101, Mi lstone, Hadden Neck, PWR, and ATI (Associated Technology Incorprate) to the United States c〇nnticu1: Yankee Power Plant, dTS

1224024 V. Description of the invention (3) (Diversified terhnni ^ · (Boric An * H p gles serVlce! Nc ·) Development of bars ^ r ecovery System), South Korea's Krosys also developed H plant before the KEPC0 power plant waste system. CA of these traditional techniques repels the second; the membrane has a relatively low rejection rate due to its looseness, and the oxide of fume is f: II. The boron rejection rate was 15%. Although it still meets the separation effect, the CA membrane has a limited range (ρΗ = 3_7), and has a low dream dioxide rejection rate, low water flow ^ (5 GPD / ft2), and high use pressure (at least 400psi). , Low use temperature (maximum 35.0 'hollow fiber R (m easy to foul plugs, does not meet environmental requirements and economically expensive and other shortcomings. In view of the shortcomings of traditional techniques, the inventor finally developed a kind of long-term research and experiment The system and method for purifying and reusing boric acid solution by using reverse osmosis membrane can purify and reuse radioactive high boric acid solution containing excessively high silicon dioxide in the main system of pressurized water nuclear power plant. (Reference: Avi jit Dey, Gareth Thomas, Kiran Arum Kekre, and Tao Guihe, &quot; Part 1: Effect of

Interstage Caustic Dosing on The Silica, Boron and Organic Removal Using Double-Pass R0, f, Ultrapure Water, pp.52-58 (July / August 2001); Frank X. McGarvey, &quot; Use of Boric Acid in Nuclear Reactor From AN Ion-Exchange Standpoint ,; Ultrapure water, pp.47-52 (October 1995); David H. Paul, &quot; Understand-ing Reverse Osmosis Membranes, n Ultrapure Water, pp.50-52 (Ultrapure Water, September 1998); Jimmy Gelen, &quot; Removing Silica by Reverse Osmosis, M

Page 9 1224024 V. Description of the Invention (4),

Filtration Technology Review, ρρ · 43 (April 1991); Busch Goncarovs and Richard K. Doyle, &quot; A Cost Effective Approach to Silica Reduction, M Waste Management 88. Vol 1, pp · 483-486; Alex 0 Hobbs and PERaleigh , &quot; Review of Operating LWR Experience With Membrane Technology, &quot; Waste Management 83.

Vol1, pp. 22 3-231.) III. Contents of the invention

The main purpose of the present invention is to provide a special system and method for purifying and reusing a sodium concentration shed acid solution in a reverse osmosis membrane, which can be used for purifying a solution containing excessively high silicon dioxide radioactive perboric acid in the main system of a pressurized water nuclear power plant. A system and method for purification and reuse of boric acid by a reverse osmosis separation method. In order to achieve the above object, the reverse osmosis separation method of the present invention uses a reverse osmosis thin and medium porosity to separate, and the molecular weight cut off (MWC0) to remove the solute in the solution to be processed to manufacture the The porosity of the membrane; traditionally, the purpose of reverse osmosis membranes in water treatment ^ = all use ^ 200 Daltons as the MWC value (Dawltons, "丨 丨 ⑽ atomic or basic unit of atomic weight), That is, when the molecular weight of the solute is greater than 200, the ears are rejected by the film

Denier: Less than 2 0 迢 ears in Tian Daozi immediately pass through the membrane. Boric acid is divided into q eartons, and silicic acid (silicon dioxide) is 100 Daltons, but in order to pass through the pure water area of Γ and #, an additional 90 Daltons are required, so the MWC0 of the film in the present invention is still 20 0 Daltons to make the shed sore

(Nitric Oxide) Rejection, to achieve separation between the two. The invention mainly includes a boric acid storage device and a concentrated liquid temporary storage device.

Page 10 1224024 V. Description of the invention (5) Two reverse osmosis membranes are installed separately. The three are connected in series by pipelines, and control valves, an electrical control device and a boric acid silicon dioxide monitoring device are arranged around the pipeline. The boric acid storage device includes a boric acid storage tank for containing a boric acid solution and receiving a purified flow liquid; a low-pressure pump for transporting the boric acid solution;-flow # for regulating the flow;-a cylindrical data collector, It is used to suspend suspended particles contained in acid solution; Yanhai concentrated liquid temporary storage device, including a / Chen fine liquid temporary storage tank, for receiving a fixed amount of shed acid solution from the boric acid storage tank and collect the concentrated boron The temperature of the concentrated solution in a temporary storage tank is increased to increase ㈣ and ；; = = pressure f and pressure drop: The reverse osmosis membrane separation device includes a reverse impurity. There are redundant raw liquid inlets, concentrated liquid outlets, and pure octa-boric acid and dioxide 々 · II, the same as. 丄, ® are used to separate the shrinkage liquid out of the purification, ——: pressure gauges, which are set at the raw liquid inlet, concentrated ^ ,. ,,,, fc々, L liquid outlets, used to control the pressure of the liquid pipeline feeding and discharging of the membrane group; two groups of flow meters, which are used to control: concentrated = floating particles into the temporary sample. It is used to pass the suspension and various treatments according to the concentrated liquid stream. ": Cut: electrical control device 4 to control the system temperature, including-automatic and the acid dioxide monitoring device to monitor water dialysis Instrument and a UV-Vis spectrometer, use boric acid in the J-position water stream and two sets of =, and perform the following steps: Xi / Chen Du straw is transported from the boric acid storage tank by the above-mentioned a · low pressure pump once 々 to the concentrated solution temporary storage tank, 疋 ~ the boric acid solution to be processed b · the main concentrated boric acid solution of the concentrated solution storage tank is then transferred to the reverse osmosis membrane

Page 11 1224024 V. Explanation of the invention (6) The boric acid is purified in the group (6), the boric acid is passed through, and the lice silicon is repelled, and most of the c. Is treated by the reverse osmosis membrane group in the temporary storage tank. The solution is sent back to the concentrated solution; &amp; The purified solution is sent back to the rotten acid storage tank and used to connect to the recipient directly :: Boron dioxide in the boric acid storage tank to the recontrol device; set = required; ::! By electricity:. The required purification of boric acid can be achieved through the above system and steps. The boronic acid and dioxin of Axiao are able to have a deeper understanding of the present invention: the detailed explanation of the consistent solution of the embodiment IV. The embodiment Figure 1 is a schematic diagram of the reverse osmosis system of the present invention, including a Deletion of acid storage, storage and reuse 2 (1) includes _deletion of acid storage tank (⑴), a set of electromagnetic. ; The switch for the storage and processing procedure of the rotten acid,-the low-pressure pump (13) is used to control the acid solution, the factory flow meter (14), and ^) to transmit the to-be-treated and a cylindrical filter. The device (15) is used to process the flow of 3 to 1 to suspend the particles. If there are too few suspended particles in the bypass line of the bypass pipeline contained in the boric acid solution to be treated, it can be removed as needed. The pipeline is connected to ν ^ Λ / Λ = (2), and it is connected to the naphthalic acid storage device (21) ']. Therefore, it is necessary to provide a concentrated liquid temporary storage tank (21). Page 12 1224024 V. Description of the invention (7) The liquid is warmed to improve the separation efficiency of the acid t on the south side, the dioxide of stone dioxide, and a high-pressure eaves ring pump (23) to adjust the pressure; a reverse osmosis membrane separation device (3) 'is temporarily stored with the concentrated liquid The device (2) is connected to the pipeline, and the pipeline is also provided with several control valves. The reverse osmosis membrane separation device (3) includes a reverse osmosis membrane group (3 1) and two pressure gauges (3 2 ′) (3 3 ′). (3 4 ′), two sets of flow meters (3 5) (35, 5), and a cylindrical filter (3 6); wherein the reverse osmosis membrane group (3 1) is made of specially manufactured Membrane Polyamide film (HS-BP1-4040CST), at a normal temperature (&lt; 3 5 C), although the boron repellency is high, it can increase the use temperature to achieve the unique low repulsive force and silicon dioxide High repulsion to increase the efficiency of separation, the reverse osmosis membrane group (31) is provided with three pipelines, a raw liquid inlet (32), a concentrated liquid outlet (33) and a purified flow liquid outlet (34). Pressure gauges are set on it, respectively, to detect the pipeline pressure of the membrane group feed, discharge and purified flow liquid; the two sets of flow meters are also set at the concentrated liquid outlet (33) and the purified liquid outlet (34) To control the flow of concentrated liquid and purified flow liquid; the cylindrical filter (36) is used to filter the suspended particles in the concentrated liquid flow and enter the concentrated liquid temporary storage tank (21), where the reverse osmosis membrane enters the water The highest pressure can reach 260 psi, which is the oldest and the best.: 1 Ask about Knab up to 95 C, the flow rate of purified flow can be high &j; the flow rate of the liquid machine can be up to 4 1 GPM; the electrical control device β control panel 'It is equipped with a plurality of power indicator lights and an open system of pump operation, temperature and pressure Control and system start-up, system application Chu 1τ mechanical net, and the boric acid silica monitoring device (52 ^, used to monitor W-fractional analysis = 51) and a UV-visible spectrum, and according to the following Step (/ position; ^ Wei and the concentration of stone dioxide; borrow

Page 13 1224024 V. Description of the invention (8) a. Low, the pump is transported from the butterfly storage essence to the condensed temporary storage tank, and the butterfly acid solution to be processed is stored in the tank. B. The concentrated liquid temporary storage tank is to be treated. The boron group is treated for purification of boric acid, and most of the liquids are passed on to the reverse osmosis membrane boric acid; the silicon oxide is repelled, and most C · are processed by the reverse osmosis membrane group to generate koji—in the temporary storage tank, the purification process The produced gentleman = ί bath solution and then returned to the concentrated solution; 、, tun, and grain solution is returned to the boric acid storage tank and repeat steps a ~ C until the acceptable level when the boric acid storage is used; the purified two lice Reduce the silicon to the re-control device, set the required conditions to reach ^ person ^ ^ can be connected at any time by electricity, the same: Temple can also be re-connected-computer system = = = = acid purification operation wrong due to the above system and step method is two The result of the separation of silicon. "In order to better understand the efficacy of the present invention, boric acid and dioxygen, the results are explained here. The boric acid that can be treated by the present invention; Fourth, the attached table tests up to 83.63ppm of boric acid-reverse osmosis-emulsification The concentration of silicon reverse osmosis membrane is more than 97%, which is practical. Dioxin also provides the reverse osmosis thinner 1 or the high-concentration boric acid that does not contain radioactivity. In combination with the technologies that limit emissions within any environmental protection regulations, the present invention has the following advantages: Liquid is widely used. First, the separation characteristics of reverse osmosis membranes in aqueous solutions, such as the above-mentioned boric acid and oxalic acid can reach the sub-set of solute bite j excellent separation effect.

V. Description of the invention (9)

Third, the use of two temperature reading, silicon, silicon dioxide separation can increase the separation effect, so that boric acid and dioxygen, the application of other inventions contained in the boric acid solution to be treated helmets% 玛 塑 # 贝 如 Calcium, Magnesium 4 has any negative impact on the ..., so it does not affect the application of the present invention. The solution to be treated with tetraboronic acid contains a micron-sized porosity filter to remove it, and its durability. For suspended particulate impurities, the use of the membrane system can be increased by using five or six methods, which can achieve the acid removal quality required in the main cooling car system of pressurized water nuclear power plants, and minimize the reuse, saving operating costs and environmental protection. Requirements. * Lilijiang The advantages of the present invention for boric acid five without the same level of radioactivity. There are also those mentioned above, which are only the preferred embodiments of the present invention. The scope of the present invention can be limited. According to the above, it cannot be used to ensure that the intended purpose of the invention can be achieved, and a special dagger is provided. The present invention and a system and method for reusing a high-concentration boric acid solution can purify and regenerate boric acid by a reverse osmosis and permeation separation method in a main system of a power plant which can permeate a membrane and purify a water-containing core containing excessively high silicon dioxide and radioactive boric acid. It can be used for purification, and an invention patent application is filed according to law. For the industry

Page 15 1224024 Simple illustration of the diagram, 5. Simple illustration of the diagram u Figure 1 shows the system of the embodiment of the present invention Figure 2 shows the boric acid of the embodiment of the present invention Figure 3 shows the step flow of the method of the present invention Figure 4 It is the experimental data table of the present invention. [Description of symbols] (1) Boric acid storage device (1 2) Solenoid valve (1 4) Flow meter (2) Concentrated liquid temporary storage device (2 2) Heater (3) Reverse osmosis membrane separation Device (3 2) Raw liquid inlet (3 4) Purified flow liquid outlet (35) (35 ') Flow meter (4) Electrical control device (5 1) Automatic titration analyzer architecture diagram and silicon dioxide monitoring device diagram Grid (1 1) shed acid temporary storage tank (1 3) low pressure pump (1 5) cylindrical filter (21) concentrated liquid temporary storage tank (2 3) high pressure circulation pump (3 1) reverse osmosis membrane group (3 3) Concentrate outlet (32 ') (33') (34 ') pressure gauge (3 6) cartridge filter (5) boric acid silicon dioxide monitoring device (52) UV-visible light spectrometer

Page 16

Claims (1)

1224024 6. Scope of patent application · 1. A boric acid purification and reuse system for reverse osmosis separation method ^ It uses thin-film polyamide reverse osmosis membrane to separate boric acid and silicon dioxide in boric acid solution. It includes: a boric acid storage device, including: a boric acid storage tank, which is used for holding boric acid stock solution and recovering and purifying A low-pressure pump to transport boric acid stock solution; a flow meter to regulate the flow rate; a cylindrical filter to filter suspended &amp; floating particles contained in the shed acid stock solution, a concentrated liquid temporary storage device, including : A concentrated liquid temporary storage tank is used to receive the boric acid stock solution from the boric acid storage tank to transfer the amount of boric acid liquid to be processed and collect the concentrated boric acid liquid. A heater provides a concentrated liquid temporary storage tank to warm the concentrated liquid to improve the concentration of boric acid, Separation efficiency of silicon oxide; a high-pressure circulating pump, which provides appropriate water pressure to overcome reverse osmosis pressure and pressure drop as required; a reverse osmosis membrane separation device, which includes: a reverse osmosis membrane group, connected with three pipelines, and a raw liquid inlet , Concentrated liquid outlet and a purified flow liquid outlet; three sets of pressure gauges are respectively set at the original liquid inlet, concentrated liquid outlet and purified liquid outlet, which are used to adjust the pressure of the film group feed, discharge and purified liquid pipeline; Page 17 1224024 VI. Patent application scope group flowmeter [to control the flow of concentrated liquid and purified flow liquid 2 4 5 Measured into an electric number and electricity operation, etc .; a boric acid-purple boric acid which transports each boric acid as specified in the application If you apply for specialization and re-purchase online, you can apply for specialization and re-purchase online. For example, you can apply for specialization and re-purification of radioactivity. For example, you can apply for a special cylindrical filter to the control device in the temporary storage tank. Visible light and silicon dioxide are monitored by silicon oxide, and the solution is used in each device, and purification is performed. The first range of profit system can be a manual control range of the first range system, its analysis or non-linear range of the first range of system, which is used to filter suspended particles in the concentrated liquid stream is provided with a control panel, which There are multiple switching buttons on the system to control the pumping force of the system, as well as system startup and shutdown measurement devices, including an automatic drip analyzer and spectrometer to monitor the concentration of water flow at various locations; pipelines are connected in series and equipped with The pump and the control valve are controlled by a computer system or a computer to automatically control the electrical control device of the pure boric acid in the reverse osmosis separation method described in the system item by controlling the electrical control device. According to the reverse osmosis separation method described in the item, the pure boric acid and middle silicon dioxide monitoring device can be set for analysis. The boric acid purified in the reverse osmosis separation method described in item 1 is a boric acid purified in the reverse osmosis separation method described in item 1 containing a radioactive or unfavorable range. Page 18 I1224024 VI. Scope of patent application and re-interest. 6. If applying for specialization and re-liton to make 〇7, if applying for specialization and re-liability for special manufacturing 8. A reverse osmosis, such as applying for specialization and re-liability a · Low-pressure solution to b · ίchen shrink film Group and let the multi-c · reverse osmolyte temporarily acid storage repeat the a ~ c to accept the gas control device. The first range of the system is used, and the first range of the thin-film poly-permeation separation method is the first system of the system. The system is used to store the concentrated solution of boric acid in the temporary storage tank. Medium, pure tank; Steps to the extent; Set the required steps described in the desired item of the reverse amine R 0 boric acid Purify the tank in the following steps; Process the purification of zeolite, boron acid For storage and purification of the product, it is recommended to use * Μ β Μ See 'L where the boric acid being treated is a fluid or suspended solids, and the pure boric acid' system 'of the reverse osmosis separation method described in item 1 where the MWC0 of the reverse osmosis membrane is 200 otolithic acid, dentifrice, silicon dioxide repulsion, connected to the separation of the two osmotic acid pure osmosis membrane group (31), using membrane (HS-BP1 -4040CST). The purification and reuse methods are the pure boric acid steps of the reverse osmosis separation method: a certain amount of boric acid solution to be treated is sent to the reverse osmosis. Most of the silicon dioxide is rejected, and the raw concentrated solution is sent for purification. Solution = 丨: Dioxide reduction to Ziya can be purified at any time by boronic acid purified by electricity to 1 charge