Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
  • D21C9/16—Bleaching ; Apparatus therefor with per compounds
  • D21C9/163—Bleaching ; Apparatus therefor with per compounds with peroxides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/32—Packing elements in the form of grids or built-up elements for forming a unit or module inside the apparatus for mass or heat transfer
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B15/00—Peroxides; Peroxyhydrates; Peroxyacids or salts thereof; Superoxides; Ozonides
  • C01B15/01—Hydrogen peroxide
  • C01B15/022—Preparation from organic compounds
  • C01B15/023—Preparation from organic compounds by the alkyl-anthraquinone process
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
  • B01J2219/322—Basic shape of the elements
  • B01J2219/32203—Sheets
  • B01J2219/3221—Corrugated sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
  • B01J2219/322—Basic shape of the elements
  • B01J2219/32203—Sheets
  • B01J2219/32213—Plurality of essentially parallel sheets
  • B01J2219/3222—Plurality of essentially parallel sheets with sheets having corrugations which intersect at an angle different from 90 degrees
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
  • B01J2219/322—Basic shape of the elements
  • B01J2219/32203—Sheets
  • B01J2219/32224—Sheets characterised by the orientation of the sheet
  • B01J2219/32227—Vertical orientation

Definitions

• the present invention relates to an installation for the production of hydrogen peroxide according to the self-oxidation technique of an anthraquinone derivative, of the type comprising a catalytic hydrogenator supplied with hydrogen; an oxidizer supplied with a fluid containing oxygen, in particular air; an extractor supplied with water; and means for passing a working solution containing at least one anthraquinone derivative in solution in at least one organic solvent, successively into the hydrogenator, into the oxidizer and into the ex-tractor, then recycle it to the hydrogenator.
• a catalytic hydrogenator supplied with hydrogen
• an oxidizer supplied with a fluid containing oxygen, in particular air
• an extractor supplied with water
• means for passing a working solution containing at least one anthraquinone derivative in solution in at least one organic solvent successively into the hydrogenator, into the oxidizer and into the ex-tractor, then recycle it to the hydrogenator.
• the pressures indicated are relative pressures (or overpressures).
• the operating parameters of the self-oxidation installation mentioned above are adapted so as to allow the use of a working solution having, throughout the installation, a hydrogen peroxide equivalent as high as possible, for example a hydrogen peroxide equivalent greater than 11 g / 1, or even more.
• patent application FR-A-2,086,166 recommends the use of a working solution which can produce, after oxidation, an amount of the order of 16 g of hydrogen peroxide per liter. working solution.
• the equivalent hydrogen peroxide is at least 16 g / 1 at the inlet of the oxidizer.
• Conventional installations using a high hydrogen peroxide equivalent have many drawbacks.
• the object of the present invention is to overcome the drawbacks mentioned above.
• the object of the invention is to provide a plant for the production of hydrogen peroxide according to the auto-oxidation technique, which is particularly well suited from the point of view of investment, the cost of operation and safety in real industrial conditions.
• the object of the invention is to provide an installation allowing the production of hydrogen peroxide directly on the consumption site by certain installations such as installations for the manufacture of paper pulp.
• the subject of the invention is an installation for producing hydrogen peroxide according to the self-oxidation technique of an anthraquinone derivative, of the aforementioned type, characterized in that provision is made for means for diluting the working solution from the hydrogenator.
• this installation may include one or more of the following characteristics:
• the dilution means include means for diverting part of the working solution from the extractor to the oxidizer without the latter passing through the hydrogenator; - the bypass means are adapted to drift to the oxidizer between 15 and 45% by volume of the working solution from the extractor;
• bypass means are adapted to divert to the oxidizer a third by volume of the working solution from the extractor;
• the hydrogenator is suitable for producing a working solution as an output with a hydrogen peroxide equivalent of between 8 and 15;
• Means are provided for mixing the reduced working solution from the hydrogenator and the oxidized working solution coming directly from the extractor, as well as means for directing the mixture thus formed towards the oxidizer;
• bypass means and the mixing means are adapted to obtain a working solution at the inlet of the oxidizer having a hydrogen peroxide equivalent of between 7 and 9;
• the bypass means comprise a bypass line disposed between a line for recycling the oxidized working solution, which connects an outlet of the extractor to an inlet of the hydrogenator, and a line for supplying the oxidizer with solution working which connects an outlet of the hydrogenator to an inlet of the oxidizer;
• a heat exchanger is provided between the line for recycling the oxidized working solution and the line for supplying the oxidizer with the working solution and in that said bypass line is connected to the upstream recycling line. of the exchanger, and to the supply line downstream of the exchanger;
• the oxidizer comprises an envelope containing gas-liquid contact means constituted at least in part by simple perforated trays or trays similar to distillation trays, or else by an organized packing, in particular a corrugated-cross packing.
• FIG. 1 schematically shows an installation for producing hydrogen peroxide in accordance to the invention
• FIG. 2 schematically represents in perspective the general arrangement of a part of the oxidizer equipped with a corrugated-cross packing
• FIG. 3 shows in exploded perspective the constitution of an element of the lining of Figure 2.
• the installation shown in FIG. 1 comprises three main apparatuses in the form of columns: a catalytic hydrogen generator 1, a counter-current oxidizer 2, and a water extractor 3. It also includes numerous equipment associated with these three apparatuses , of which only some have been represented. Thus, a booster-condenser assembly 4 for recirculating the mixture gaseous containing hydrogen is associated with the hydrogenator.
• a filter 6, a pump 7, a heat exchanger 8, a mixer 9, a water cooler 10 are connected in series on a pipe 11 for supplying the oxidizer 2 with working solution connecting an outlet 12 of the hydro-generator 1 at an upper inlet 13 of the oxidizer 2.
• the installation further comprises a head condenser 14 and an air compressor 15 associated with the oxidizer; a pipe 16, as short as possible, connecting the base of the oxidizer 2 to that of the extractor 3; and a coalescer 18 and a pump 19 for recycling the working solution.
• FIG. 1 also shows a line 20 supplying the hydrogenator with additional make-up gas, a line 21 supplying air to the compressor 15, a line 22 supplying the ex ⁇ tractor 3 in demineralized water, a pipe 23 for producing hydrogen peroxide, which leaves from the base of the extractor 3 and ends at an installation 24 consuming hydrogen peroxide at the same concentration, and a line 25 for recycling the working solution carrying the pump 19 and connecting an outlet of the coalescer 18 to the base of the hydrogenator 1, passing through the heat exchanger 8.
• a bypass line 26 is provided between the recycling line 25 and the mixer 9. It is tapped upstream of the exchanger 8 on the recycling line 25.
• the installation 24, which is located on the same site as the installation for producing hydrogen peroxide, can in particular be a pulp bleaching installation.
• the hydrogen peroxide production installation includes many other equipment well known in the art and not shown, such as means regeneration of degraded products of the working solution, implementation of the catalyst, recovery of solvent, etc.
• part of the oxidized working solution consisting of at least one anthraqui ⁇ nonic derivative and at least one organic solvent is introduced into the base of the hydrogenator 1 via the recycling pipe 25 connected to the discharge of the pump 19, and a stream of gas containing hydrogen is also introduced at the base of the hydrogenator.
• This gas stream consists on the one hand of the gas stream drawn off at the top of the hydrogenator, recirculated by the booster-condenser assembly 4, and on the other hand of make-up hydrogen arriving via line 20.
• This part of the oxidized working solution is thus partially reduced.
• the reduced solution, supported from the base of the hydrogenator by the pump 7 via the filter 6, therefore contains hydroquinone derivatives (for example 80% tetrahydroanthrahydroquinone and 20% anthrahydroquinone).
• the anthraquinone derivative constituting the working solution is preferably chosen from the 2 alkyl 9.10 anthraquinones in which the alkyl substituent comprises from 1 to 5 carbon atoms, such as the methyl, ethyl, sec-butyl, tert-butyl radicals , tertio-amyl, iso-a yl, as well as the corresponding tetrahydro-5,6,7,8 derivatives, or among the dialkyl 9,10 anthraquinones in which the alkyl substituents, identical or different, comprise from 1 to 5 carbon atoms, such as methyl, ethyl and tert-butyl radicals, for example 1.3 dimethyl, 1.4 dimethyl, 2.3 dimethyl, 2.7 dimethyl, 1.3 diethyl, 2.7 ditertio-butyl, 2 ethyl 6 tert-butyl and the corresponding tetrahydro-5,6,7,8 derivatives.
• the organic solvent constituting the working solution is preferably a mixture of a non-polar compound and a polar compound.
• the non-polar compound is preferably chosen from petroleum fractions with a boiling point above 140 ° C. mainly containing aromatic hydrocarbons containing at least 9 carbon atoms, such as the isomers of trimethylbenzene, the isomers of tetramethylbenzene , tert-butylbenzene, isomers of methylnaphthalene, isomers of dimethylnaphthalene.
• the polar compound is preferably chosen from saturated alcohols preferably containing from 7 to 11 carbon atoms, such as diisobutylcarbinol, trimethyl-3,5,5 hexanol, iso-heptanol, esters of carboxylic acids such as methyl acetate cyclohexyl sold under the name "Sextate", hexyl acetate, butyl benzoate, ethyl heptanoate, esters of phosphoric acid such as tributyl phosphate, tri phosphate (2 ethyl butyl), tri phosphate (2 ethyl hexyl), tri phosphate (n-octyl), tetrasubstituted ureas such as tetra (n-butyl urea).
• saturated alcohols preferably containing from 7 to 11 carbon atoms, such as diisobutylcarbinol, trimethyl-3,5,5 hexanol, iso
• hydrogen peroxide equivalent is meant the quantity of hydrogen peroxide, expressed in grams, that a liter of working solution is capable of supplying at the outlet of the oxidizer if the yield of this step is 100 %.
• This poten ⁇ tial mass concentration of peroxide corresponds to a molar concentration which is equal to the molar concentration of all of the reoxidizable anthrahydroquinone forms in the working solution. It depends on the one hand on the concentration in anthraquinone forms of the starting working solution, and on the other hand on the conditions of hydrogenation in the hydrogenator 1, as well as on possible dilutions of the solution reduced work.
• the hydrogenation is carried out at a temperature of between 50 and 70 ° C., with a pressure in the gaseous sky of the hydrogenator (pressure which regulates the flow of hydrogen) from 0.8 to 1.5 bar approximately, and the hydrogen peroxide equivalent at output 12 of the hydrogenator 1 is adjusted at a value of between 8 and 15 g / l approximately, and preferably between 9 and 12 g / l approximately, by adjusting the residence time in the hydrogenator, for a given concentration of anthraquinone forms.
• the reduced working solution drawn from the hydrogenator is filtered at 6 to remove all traces of catalyst, then cooled at 8. It is then diluted, in mixer 9 with the complementary part of the partially oxidized working solution coming from bypass line 26 and whose hydrogen peroxide equivalent is close to zero.
• This complementary part of the working solution corresponds to approximately 15 to 45% by volume, and preferably to approximately one-third by volume of the total working solution coming from the extractor 3.
• This part of oxidized working solution is therefore directed directly to the oxidizer 2 without having passed through the hydrogenator 1.
• the flow rate in the bypass line 26 is adjusted so that the working solution obtained at the outlet of the mixer 9 has an equivalent hydrogen peroxide included between 7 and 9 approximately.
• the hydrogen peroxide formed by the oxidation reaction is withdrawn from the base of the oxidizer, in an amount per unit volume of the oxidized working solution equal to the product of the hydrogen peroxide equivalent equivalent to l input 13 of the oxidizer by the efficiency of the oxidizer.
• This liquid is sent directly via line 16, thanks to the difference in driving pressure, to the base of the extractor 3, which operates a little above atmospheric pressure.
• the extractor is carried out a liquid-liquid extraction by means of demineralized water introduced at the top of the extractor.
• a water-hydrogen peroxide solution is drawn from the base of the latter, the hydrogen peroxide concentration of which is adjusted to the value necessary for its direct use in the installation consom ⁇ matrix 24.
• the hydrogen peroxide concentration is chosen to be less than 15% by weight, for example between 5 and 12% by weight.
• the working solution separated from the hydrogen peroxide is withdrawn from the top of the extractor 3, freed from the droplets of aqueous phase which it has entrained in the coalescer 18. Part of this solution is sent by the pump 19 to the heat exchanger 8, in which it heats up, and from there recycled to the base of the hydrogenator 1. The other part is sent to the mixer 9 via the bypass line 26.
• the oxidizer 2 comprises an outer casing containing an organized lining, or simple perfo ⁇ res trays or trays of the type of distillation trays, that is to say each with a liquid guard, bubbling orifices for the gas rising through this guard, and means for lowering the liquid from one tray to the next, or a combination of an organized lining and such trays.
• the organized packing if there is one, is preferably of the so-called "corrugated-cross" type.
• FIG. 2 illustrates the general arrangement of the current part of the oxidizer containing such a lining.
• This main part essentially comprises a cylindrical shell 27 in which are stacked packing elements 28 of generally cylindrical shape.
• Each element 28, of the "wavy-cross" type comprises a packet of strips 29 having a general rectangular shape and wavy obliquely, the waves preferably having a triangular profile. The direction of inclination of the waves is reversed from one strip to the next, as can be seen in FIG. 3.
• each strip On each face, each strip has wave peaks 30 and wave troughs 31 defining a multitude of inclined channels.
• each element 28 is angularly offset by 90 ° relative to the following, as seen in Figure 2, and each strip has a multitude of perforations, not shown.
• the installation as described here uses a hydrogenator 1 having a high efficiency. Since only part of the working solution (approximately 2/3 by volume) is treated in the hydrogenator, the dimensions of the latter can be reduced compared to the hydrogenators of installations in which all of the solution work is covered in this one. Furthermore, the working solution introduced into the hydrogenator has a fairly high concentration of anthraquinone forms, which allows easy hydrogenation. This makes it possible to obtain a hydrogen peroxide equivalent of between 8 and 15.
• the oxidizer 2 is supplied with a working solution of which the hydrogen peroxide equivalent is between 7 and 9.
• the relatively low value of this equivalent compared to the values used in the installations known limits the temperature in the oxidizer without risk of crystallization of the solution.
• the low temperature in the oxidizer leads to a low partial pressure of organic vapor in the gaseous sky (for example less than 2600 Pascals and preferably less than 1300 Pascals).
• the mixture thus contained in the oxidizer then has characteristics suf ⁇ ficiently distant from the explosive conditions.
• the same advantages are found in the pipe 16 as well as the extractor 3, in which the concentration of species which can form hydrogen peroxide in the presence of water, or the concentration of hydrogen peroxy ⁇ is limited.
• the "corrugated-cross" packings like the trays occupy a smaller volume than the loose packings, which makes it possible to reduce the dimensions of the oxidizer.
• the relatively low oxidation temperature also brings, as another advantage, the possibility of using oxygen-enriched air, or even pure oxygen, in the safety, in order to reduce the time. of stay of the solution in the oxidizer. Indeed, when the residence time is longer in short, the dimensions of the apparatus can be further reduced, and the quantity of degraded products of the working solution is reduced.
• the installation described here uses a bypass of the recycling line for the dilution of the reduced working solution from the hydrogenator. It is also possible to use any other suitable device.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Wood Science & Technology (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Catalysts (AREA)
• Fats And Perfumes (AREA)
• Treatment Of Water By Oxidation Or Reduction (AREA)
• Oxygen, Ozone, And Oxides In General (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9476579

Family Applications (1)

Country Status (14)

Families Citing this family (6)

Family Cites Families (5)

• 1995
  • 1995-02-28 FR FR9502317A patent/FR2730986B1/fr not_active Expired - Fee Related
• 1996
  • 1996-02-14 JP JP8526054A patent/JPH11500997A/ja active Pending
  • 1996-02-14 EP EP96904143A patent/EP0812299A1/fr not_active Withdrawn
  • 1996-02-14 US US08/894,138 patent/US5902559A/en not_active Expired - Fee Related
  • 1996-02-14 NZ NZ302323A patent/NZ302323A/xx unknown
  • 1996-02-14 AU AU48350/96A patent/AU4835096A/en not_active Abandoned
  • 1996-02-14 CZ CZ972695A patent/CZ269597A3/cs unknown
  • 1996-02-14 CN CN96192214A patent/CN1176628A/zh active Pending
  • 1996-02-14 BR BR9607051A patent/BR9607051A/pt not_active Application Discontinuation
  • 1996-02-14 WO PCT/FR1996/000245 patent/WO1996026898A1/fr not_active Application Discontinuation
  • 1996-02-14 CA CA002214087A patent/CA2214087A1/en not_active Abandoned
  • 1996-02-27 CO CO96009196A patent/CO4560351A1/es unknown
• 1997
  • 1997-08-25 NO NO973895A patent/NO973895L/no not_active Application Discontinuation
  • 1997-08-27 FI FI973512A patent/FI973512A/sv unknown

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events