• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    High purity aqueous alkali hydroxide solutions containing predetermined, low concentrations of alkali metal halide are obtained in the anode compartment of an electrolytic cell using a cationic ion exchange membrane by conducting the electrolysis under controlled conditions such that the difference between the concentration of alkali metal halide in the anode compartment and the limiting concentration of alkali metal halide in the anode compartment is within a defined range.
    公开号:SU818493A3
    申请号:SU762379616
    申请日:1976-07-14
    公开日:1981-03-30
    发明作者:Секо Маоми；Огава Синсаку；Такемура Рейдзи
    申请人:Асахи Касеи Когио Кабусики Кайся (Фирма)；
    IPC主号:
    专利说明:

    The invention relates to processes for producing chlorine and sodium hydroxide by electrolysis of sodium chloride solutions in electrolyzers with an ion-exchange membrane.
    The purpose of the invention is to increase productivity and increase the efficiency of the process.
    In FIG. 1 shows a graph of voltage across the electrolyzer versus current density; in FIG. 2 is a graph of voltage loss (Ohm) electro. a lithium bath depending on the distance between the electrodes; in FIG. 15 3 is a graph of current efficiency, depending on the concentration of sodium chloride; in FIG. 4 is a graph of W Na „/ W N0H 'depending on (C-C o ).
    Example 1. Carry out the process 78 of producing chlorine and sodium hydroxide in an electrolyzer in which the anode is made of a titanium network coated with oxides of ruthenium, titanium or zirconium, the cathode is made of a steel mesh · 25 ki. Cathode and anode chambers are separated by a cation-exchange composite membrane manufactured overlay film of copolymer of tetrafluoroethylene and perftorsulfonilvinilovogo ester The available 80 present an equivalent weight of 1500, a similar plate copolymer having an equivalent weight of 1100, Composite film on a substrate strengthened polytetrafluoroethylene fabric having a size of 35 to 40 mesh cells ( 40 holes by 2.54 cm).
    Anolyte and catholyte are circulated for 1 h in the absence of current flow at three different fixed concentrations of chloride — 1.0 N, 2.5 N, and 4.0 N.
    • Measure the amount of sodium chloride that migrates to the cathode chamber and the difference in the concentration of sodium chloride in the anode and cathode chamber 45.
    The ratio d./D is determined from the formula d _ [WnoCfJo
    D 'С-С ~ г ~' where [W NaCt ] 0 is the value of migration of sodium chloride in the absence of electric current;
    (C-Cj) is the difference in the concentration of sodium chloride in the anode and cathode chambers.
    The results are summarized in table.
    The concentration of anolyte, equiv · CM ' 3 [Wmae ) 0 equiv / s cm 2 d / D ' 0.001 3.37 -10 ' 9 2.9710 5 0.0025 5.72.-10 ' 3 4.37-10 5 0.004 10.39 Yu ' 9 3.85 -1 O 5 Average3.73-10 5
    They carry out the electrolysis process using a 4.0 N sodium chloride solution at various current densities i — 0.2, 0.3, 0.4, and 0.5 A cm 2 .
    The voltage of the bath is measured and a graph of the voltage across the cell E versus the current density Ι / S is plotted (see Fig. 1, line a). The point E O = 2.5 V, extrapolated relative to i = 0, displays the voltage of the electrode and E-E o - the voltage drop caused by the membrane and the liquid.
    In the same cell, an electrolysis process using 4.0 N. a solution of sodium chloride and a fixed current density of 0.5. A cm ' 2 . The voltage E on the cell is measured at a different distance 1 between the electrodes (see Fig. 2, line a). Point E = 1.33 obtained by extrapolation for 1 = 0 and characterizes the voltage drop only on the membrane. Membrane resistance calculated based on Ohm's law
    R = r = 1 "= 2.66 ohm cm" 2.
    The proportionality coefficient K is calculated by the formula. K- -3.7E.1O "jljj.1,40.10".
    Electrolysis is continued for 10 hours at a current density of 0.5 A cm 2 at a concentration of sodium chloride in the 5θ anode chamber, variable from 1.0 n, 1.5 n, 2.0 n, 2.5 n to 4, 0 n The current efficiency is calculated based on the increase in sodium hydroxide content in the external container connected.
    to the cathode compartment through pipelines to circulate the alkali metal hydroxide.
    The dependence of the current efficiency on the concentration of sodium chloride is shown 5 in FIG. 3. The concentration at the point where there is a sharp inflection of the curve is the limiting concentration. The transfer number t Na is equal to the current efficiency expressed in decimal values. From FIG. 3, line a shows that the transfer number is 0.78, and the maximum concentration of C o is 1.76 N.
    Substitute the obtained values in the equation
    ... (c-s.).
    No
    Graphically, this relationship is shown in FIG. .4 line a.
    From this graph it is seen that if the work is carried out at a current density of 0.5 A-cm 2 , then the value of the expression (C-C o ) should be less than 0.4-1 O * 8
    F and the expression is K 'U' t, in this case it is equal to - (s-c 0 ) = J (C ~ C O > Να.
    1,2.8-ΙΟ ' 4 .
    PRI me R 2. Carry out the process at a current density of 0.5 A / cm 2 using '2.0 n ·. sodium chloride solution at (С-С о ) = О, 24 Ν.
    The current efficiency and the sodium chloride content in sodium hydroxide are calculated from the amount of sodium hydroxide formed and the concentration of sodium chloride in the aqueous sodium hydroxide solution.
    Yield c current is 78% and 40 centration concentration of sodium chloride is 210 mg / l. The concentration of sodium chloride was equalized after approximately 40 hours. The value of the expression d (CC 0 ) was 1.59-10. 4 5
    For comparison, electrolysis is carried out under the same conditions, but using 2.5 N. solution. The concentration difference (С-С о ) was 0.74 N, and the expression о <(С-С о ) = 4.81 -10 ' 4 . At the same time, the concentration of sodium chloride in the resulting sodium hydroxide increases sharply and amounts to 640 mg / L.
    Example Z. Electrolysis 55 is carried out at a current density of 0.75 A-cm 2 for 10 hours at various concentrations of sodium chloride - 1.5; 2.0; 2.5; 3.0 and 4.0 N in the anode chamber.
    The current efficiency is calculated based on the increase in sodium hydroxide content in the external container.
    The line in FIG. 3 shows the obtained dependence of the current efficiency on the concentration of sodium chloride. The graph shows that t Nc ( = 0.78 and C about = 2.7 N.
    In FIG. 4 line B corresponds to this example. From this graph, 'it is clear that in order to obtain sodium hydroxide with a sodium chloride content of less than 400 mg / l when conducting electrolysis with a current density of 0.75 A-cm 2, it is necessary to maintain such a concentration of sodium chloride in the anode chamber so that the concentration difference (C oo) was less than 0.6 * 10 '3 eq cm "3. For verification, electrolysis was carried out at a current density of 0.75 A-cm 3 for 50 h at a concentration of sodium chloride in the anode chamber of 3 N. The difference in the concentration of С-С is 0.3 N. The value of the expression (С-Со) was 1, 33-10. Get sodium hydroxide with a sodium chloride content of 180 mg / L. The current efficiency was 78%.
    For comparison, electrolysis is carried out under the same conditions, but while maintaining the concentration of sodium chloride in the anode chamber is 4.0 N and the concentration difference (C ~ C 0 ) was 1.3 N. The value of the expression about ((C-C 0 ) was 5 , 32 · 10 ' 4. The content of sodium chloride in the resulting sodium hydroxide increases and amounts to 880 mg / L.
    When carrying out electrolysis under the same conditions, but at a concentration of sodium chloride in the anode chamber of 2.0 N, i.e. below the limiting concentration, the current efficiency decreases and amounts to 69%.
    Π PRI me R 4. Carry out electrolysis in the conditions of example 3, but at a current density of 0.3 A · cm ' 2 . The test results are shown as lines c in FIG. 3 and 4. From the graphs it can be seen that in this case t Na = 0.78 and C o = 1.10.
    A test is carried out for 100 hours, conducting electrolysis at a current density of 0.3 A cm 2 , and the concentration of sodium chloride in the anode chamber is maintained at 1.3 N. The difference in the concentration of CC about was 0.2 N. The value of the expression with ((C 0) = 2.21 -10 '4. The result is sodium hydroxide with sodium chloride Niemi containing 250 mg / l. The current efficiency was 78%. when conducting electrolysis under the same current density, but at the concentration sodium chloride in the anode chamber 2.0 N, when the difference in concentration (C o) is 0. 90 N, and the value of the expression d (C-C o) = 10.111 d '4, to give and sodium hydroxide with a content of chloride 10 Sodium chloride 1430 mg / L.
    When carrying out electrolysis under the same conditions, but at a concentration of sodium chloride in the anode chamber of 0.6 N 15 , the current efficiency was 56%.
    Similar tests were carried out with various types of membranes. The test results are presented in graphs. 20 . Lines d in the drawings correspond to testing with a membrane “obtained by applying a copolymer film of a thickness of 0.0381 mm with an equivalent weight of 1500 to a copolymer film of a thickness of 0.1016 mm with an equivalent weight of 1100 and provided with a Teflon substrate. The test was carried out at a current density of 0.5 A cm 2 .
    Line "e" in the figures corresponding to θ 3 was tested with a membrane of the same copolymer, but the copolymer film thickness with an equivalent weight of 1500 was 0.0254 mm. Tests were also carried out at a dense 35 current of 0.5 A cm -2 . ·
    Lines f correspond to tests with a membrane, one side of which has carbon groups. The thickness' of the membrane layer containing the sulfonic acid group was 0.167 mm, and the thickness of the layer containing the carboxylic acid group was 0.0102 mm.
    The tests were carried out at a current density of 0.6 A-cm 2 .
    权利要求:
    Claims (2)
    [1]
    181849 The invention relates to processes for the production of chlorine and sodium hydroxide by the electrolysis of solutions of sodium chloride in electrolytic cells with an ion exchange membrane. The purpose of the invention is to increase productivity and increase the efficiency of the process. FIG. 1 shows a diagram of the voltage on the electrolyzer versus current density; in fig. 2 is a graph of voltage loss (ohm) electro-. lytic bath depending on the distance between the electrodes; in FIG. 3 is a graph of current efficiency, depending on the concentration of sodium chloride; in fig. 4 is a graph of W gfj / W versus (C – C). Example 1. The process of producing chlorine and sodium hydroxide in an electrolyzer, in which the anode is made of a titanium mesh coated with ruthenium oxides, titanium or zirconium oxide, is carried out, the cathode is made of steel Vrrr Ti-o1 aurirruao v Kfcartu cathode and the anodic chambers are separated by a composite cation-exchange membrane made by overlaying a film of a copolymer of tetrafluoroethylene and perfluorosulfonylvinyl ether having an equivalent weight of 1500 on a similar slab of a copolymer with an equivalent weight of 1100. The composite film is fixed on a substrate watered. trafluoroethylene fabric having a mesh size of 40 mesh (40 holes per 2.54 cm. Anolyte and catholyte are circulated for 1 h with no current flowing at three different fixed concentrations of chloride — 1.0 O, 2.5 N and 4.0 N. The amount of sodium chloride that migrates to the cathode chamber and the difference in sodium chloride concentration in the anode and cathode chamber are measured. The d / D ratio is calculated from the formula d D C-SG, the migration of sodium chloride in the absence of effect of electric current; (C-Cj) the difference in the concentration of sodium chloride in the anode and cathode chambers. njoH The results obtained are summarized in person. The process of electrolysis is carried out using a 4.0 N sodium chloride solution at various current densities, 2, 0.3, 0.4 and 0.5 A-cm1. The voltage of the bath is measured and a graph of the voltage across the electrolyzer E is plotted. from the current density t / a fi and tn m I / S 1cm. FIG. 1, line a). The point ,, ,, - t, b., 2.5 V, extrapolated relatively, displays the voltage of the electrode and Е-Е - the voltage drop caused by the membrane and the liquid. In the same cell, the electrolysis process is carried out using 4.0 n. solution of sodium chloride and a fixed current density of 0.5. A-cm. The voltage E is measured at the electrolyzer at different distances 1 between the electrodes (see Fig. 2, line a). Point, 33 is obtained by extrapolation for and characterizes the voltage drop only on the membrane. The membrane resistance is calculated on the basis of Ohm’s law R ii | 2 2,66 OM-CM-I jL V у J The proportionality coefficient K is calculated using the formula 73., 40.10 Electrolysis is continued for 10 hours at a current density of 0.5 A -cm when the concentration of sodium chloride in the anode chamber varies from 1.0 N, 1.5 N, 2.0 N, 2.5 N to 4.0 N. The current output is calculated based on the increase in sodium hydroxide content in the outer container connected. 38 to the cathode compartment through the conduits to circulate the alkali metal hydroxide. The dependence of the current efficiency on the concentration of sodium chloride is shown in FIG. 3. The concentration at the point where the soup; there is a sharp bend in the curve is the ultimate concentration. The transfer number is equal to the current output, expressed in decimal terms. From FIG. 3, line a shows that the transfer number is 0.78, and the limiting concentration of Cd is 1.76 N. Substitute the obtained values into the equation L (g s} yTf t ,.- .-. NdOH. Na Graphically this dependence is shown in Fig. 4 by line A. From this graph it can be seen that if the work is carried out at a current density of 0.5 A-cm, then the value of the expression (C-Cd) should be less than 0.4-10, and the expression r -rj-r- (С-С.) (С-СЛ in i -U-tNc, in this case it is equal 1.7.8-10. EXAMPLE
    [2]
    2. The process is conducted at a current density of 0.5 A / cm using 2.0 N-. sodium chloride solution at (C-Cp) 0.24 N. The current efficiency and sodium chloride content of sodium hydroxide are calculated from the amount of sodium hydroxide formed and the concentration of sodium chloride in an aqueous solution of sodium hydroxide. The yield of g {current is 78% and the concentration of sodium chloride is 210 mg / l. The concentration of sodium chloride was equalized in approximately 40 hours. The value of the expression (j (C-Co) was 1.59-10. For comparison, electrolysis was carried out under the same conditions, but using a 2.5 n solution. (G-CO) was 0.74 N, and the expression oi (C-Cg) was 4.81 ° C. At that, the sodium chloride concentration in the sodium hydroxide produced increased dramatically and was 640 mg / l. at a current density of 0.75 A-cm for 10 hours at different concentrations of sodium chloride — 1.5, 2.0, 2.5, 3.0, and 4.0 N in the anode chamber. The current efficiency was calculated t, based on the increase in sodium hydroxide content in the outer container. The line in Fig. 3 shows the resulting dependence of the current output on the concentration of sodium chloride. The graph shows that, 78 and С 2.7 N. In Fig. 4, this example corresponds to the line This graph shows that to obtain sodium hydroxide with a sodium chloride content of less than 400 mg / l, when conducting electrolysis with a current density of 0.75 A-cm, it is necessary to maintain such a concentration of sodium chloride in the anode chamber so that the concentration difference (C-Cd ) less than 0.6 jlO eq -cm Electrolysis was carried out for the test at a current density of 0.75 A-cm for 50-h at a concentration of sodium chloride in the anode chamber of 3 N. The difference in C-Cp concentration is 0.3 N. The value of the expression (C-Cd) amounted to 1 ,. Sodium hydroxide is obtained with a content of sodium chloride 180 mg / l. The current output was 78%. For comparison, the electrolysis is carried out under the same conditions, but while maintaining the concentration of sodium chloride in the anode chamber is 4.0 N and the concentration difference (C – C) was 1.3 N, the value of the expression o (C – C) was 5.32-10. The content of sodium chloride in the resulting sodium hydroxide increases and is 880 mg / l. When electrolysis is carried out in the same conditions, but with a concentration of sodium chloride in the anode chamber of 2.0 N, i.e. below the limiting concentration, the current efficiency falls and is 69%. EXAMPLE 4. Electrolysis is carried out under the conditions of Example 3, but at a current density of 0.3 A-cm. The test results are presented as lines with in FIG. 3 and 4. From the graphs it can be seen that in this case, 78 and Co 1,10. The test was carried out for 100 hours, the electrolysis wire at a current density of 0.3 A-cm, and the sodium chloride concentration in the anode chamber was maintained at 1.3 N. The C-Cp concentration difference was 0.2 N. The value of the expression o ((C -Co) 2.21 -10 Sodium hydroxide is obtained with a sodium chloride content of 250 mg / l. The current output is 78%. When electrolysis is carried out at the same current density, but at a concentration of sodium chloride in the anode chamber 2.0 N when the difference in concentrations (C-C) is 0-, 90 N, and the value of the expression d (C-Cp) 10,11 10, a hydroxide is obtained Sodium is containing sodium chloride 1430 mg / l. When electrolysis was carried out under the same conditions, but with a sodium chloride concentration of 0.6 in the anode chamber, the current output was 56%. Similar tests were carried out with different types of membranes. The test results are presented in graphs. . Line d in the drawings corresponds to testing with a membrane obtained by applying a copolymer film with a thickness of 0.0381 mm with an equivalent weight of 1500 to a copolymer film with a thickness of 0.1016 mm with an equivalent weight of 1100 and provided with a tefpon substrate. The test was carried out at a current density of 0.5 A-cm. Lines e in the drawings correspond to testing with a membrane made of the same copolymer, but the thickness of the copolymer film with an equivalent weight of 1500 was 0.0254 mm. Tests were also carried out at a current density of 0.5 A-cm. Lines f correspond to testing with a membrane, one of the sides of which has carbonic groups. The thickness of the membrane layer containing sulfonic acid groups was 0.167 mm and the thickness of the layer containing carboxylic acid groups was 0.0102 mm. The tests were carried out at a current density of 0.6 A-cm. Claims A method for producing chlorine and sodium hydroxide by electrolysis of an aqueous solution of sodium chloride in a cell with an ion exchange membrane separating the inside of the cell into an anodic and cathodic chambers, including controlling the concentration of sodium chloride in the anodic chamber, characterized in that, in order to increase productivity and In view of the efficiency of the process, the electrolysis is carried out at a current density of 0.3-0.75 A / cm, the ratio of the density: current and the limiting concentration of sodium chloride in a A node chamber of 150-350 A / cm / eq / cm is the difference in the concentration of sodium chloride in the anode chamber and the maximum concentration of sodium chloride in the anode chamber is 0.-0.001 eq / cm, the current density and the concentration of sodium chloride in the anode chamber are adjusted so that the value of F- (C-CO) o-t / expression.-g --- did not exceed 2.74 x KLt Farad constant; HD «F С concentration of sodium chloride in the anode chamber; Cp is the limiting concentration of sodium chloride in the anode chamber; and - voltage drop across the membrane; t is the number of transfer of Na ions through the membrane; K is the coefficient of proportionality in the expression - K-R, where d is the membrane thickness, D is the diffusion coefficient of sodium chloride through the membrane ;. R is the electrical resistance of the membrane.
    ": Olf LGTg
    al
    li
     Lhsto yiv
    ,
    类似技术:
    公开号 | 公开日 | 专利标题
    CA1153982A|1983-09-20|Electrolytic production of alkali metalhypohalite and apparatus therefor
    KR830002163B1|1983-10-17|Chlorine-Alkaline Electrolyzer
    EP0777905A2|1997-06-11|Method of producing aluminum foil for electrolytic capacitors and product thereof
    US3177131A|1965-04-06|Method for the production of platinum coated titanium anodes
    US3617462A|1971-11-02|Platinum titanium hydride bipolar electrodes
    US3974058A|1976-08-10|Ruthenium coated cathodes
    US2872405A|1959-02-03|Lead dioxide electrode
    SU818493A3|1981-03-30|Method of producing chlorine and sodium hydroxide
    Krzewska et al.1984|Electrochemical determination of thiourea and glue in the industrial copper electrolyte
    Krstajić et al.1987|Hypochlorite production. I. A model of the cathodic reactions
    CA1062202A|1979-09-11|Rhenium coated cathodes
    Kikuchi et al.2001|Hydrogen concentration in water from an Alkali–Ion–Water electrolyzer having a platinum-electroplated titanium electrode
    US4545863A|1985-10-08|Automated membrane test cell apparatus and method for so using
    US3592750A|1971-07-13|Electrodes for use in aqueous alkali metal chloride electrolytes
    US4127457A|1978-11-28|Method of reducing chlorate formation in a chlor-alkali electrolytic cell
    FI82078C|1991-01-10|ELEKTROKEMISKT AVLAEGSNANDE AV HYPOKLORITER UR KLORATCELLOESNINGAR.
    US4734170A|1988-03-29|Electrolysis of aqueous solution of sodium chloride
    JP2836840B2|1998-12-14|Electrode for chlorine generation and method for producing the same
    US3933603A|1976-01-20|Electrolysis of alkali metal chloride
    CA1098076A|1981-03-24|Reduction of steel cathode overpotential
    Atkinson1959|Electrodeposition of platinum from chloroplatinic acid
    US4523984A|1985-06-18|Treatment of ion-exchange membrane
    US4316781A|1982-02-23|Method for electrolyzing alkali metal halide
    BG98450A|1995-05-31|Method for chlor-alkaline electrolysis and cell for its implementation
    JP2938815B2|1999-08-25|Method for displaying pH value of electro-generated water and pH display device for electro-generated water
    同族专利:
    公开号 | 公开日
    SE7607989L|1977-01-16|
    FR2318240B1|1979-09-28|
    DE2631523A1|1977-01-20|
    NL7607849A|1977-01-18|
    US4276130A|1981-06-30|
    DE2631523C3|1985-04-25|
    NL168011B|1981-09-16|
    BR7604568A|1977-08-02|
    GB1543249A|1979-03-28|
    DE2631523B2|1979-08-23|
    FR2318240A1|1977-02-11|
    NL168011C|1984-10-16|
    CA1084866A|1980-09-02|
    JPS529700A|1977-01-25|
    IT1064602B|1985-02-25|
    SE450498B|1987-06-29|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    GB955307A|1962-01-26|1964-04-15|Pittsburgh Plate Glass Co|Improvements in and relating to the electrolytic production of alkali metal hydroxide and chlorine|
    BE790369A|1971-10-21|1973-04-20|Diamond Shamrock Corp|METHOD AND APPARATUS FOR THE PREPARATION OF HYDROXIDES FROM HIGH PURE ALKALINE METALS IN AN ELECTROLYTIC TANK.|
    US3773634A|1972-03-09|1973-11-20|Diamond Shamrock Corp|Control of an olyte-catholyte concentrations in membrane cells|
    US3933603A|1973-04-25|1976-01-20|Asahi Kasei Kogyo Kabushiki Kaisha|Electrolysis of alkali metal chloride|
    US3904496A|1974-01-02|1975-09-09|Hooker Chemicals Plastics Corp|Electrolytic production of chlorine dioxide, chlorine, alkali metal hydroxide and hydrogen|USRE32077E|1977-06-30|1986-02-04|Oronzio Denora Impianti Elettrochimici S.P.A.|Electrolytic cell with membrane and method of operation|
    JPS5735688A|1980-08-13|1982-02-26|Toagosei Chem Ind Co Ltd|Method for electrolysis of potassium chloride brine|
    US4588483A|1984-07-02|1986-05-13|Olin Corporation|High current density cell|
    US4722772A|1985-01-28|1988-02-02|E. I. Du Pont De Nemours And Company|Process for electrolysis of sulfate-containing brine|
    GB9213220D0|1992-06-22|1992-08-05|Langton Christian M|Ultrasound bone analyser|
    JP2737643B2|1994-03-25|1998-04-08|日本電気株式会社|Method and apparatus for producing electrolytically activated water|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    JP50085777A|JPS529700A|1975-07-15|1975-07-15|Manufacturing method of high purity caustic soda solution|
    [返回顶部]