CA2214049A1 - Apparatus for feeding hydrogen peroxide to a processing unit in an industrial facility - Google Patents
Apparatus for feeding hydrogen peroxide to a processing unit in an industrial facility Download PDFInfo
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- CA2214049A1 CA2214049A1 CA002214049A CA2214049A CA2214049A1 CA 2214049 A1 CA2214049 A1 CA 2214049A1 CA 002214049 A CA002214049 A CA 002214049A CA 2214049 A CA2214049 A CA 2214049A CA 2214049 A1 CA2214049 A1 CA 2214049A1
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- Prior art keywords
- hydrogen peroxide
- plant
- processing unit
- concentration
- reserve
- Prior art date
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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
-
- 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
-
- 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
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Paper (AREA)
- Oxygen, Ozone, And Oxides In General (AREA)
- Apparatus For Disinfection Or Sterilisation (AREA)
- Storage Of Fruits Or Vegetables (AREA)
Abstract
An apparatus (10) including a main apparatus (14) provided in situ in the processing unit (12) for producing hydrogen peroxide at a working concentration, and a back-up apparatus (16) for supplying the processing unit (12) in the event of a failure of the main apparatus (14). The back-up apparatus comprises a supply (18) of hydrogen peroxide at a storage concentration higher than the working concentration, and means (20) for diluting the stored hydrogen peroxide, arranged between the supply (18) and the processing unit (12) for lowering the storage concentration of the hydrogen peroxide to the working concentration.
Description
Plant for feedinq hYdroqen peroxide to a processinq unit on an industrial site.
The present invention relates to a plant for feeding hydrogen peroxide to a processing unit on an industrial site.
It applies in particular to the feed of hydrogen peroxide to a unit for bleaching paper pulp on a paper production site.
Many industrial sites consume large quantities of hydrogen peroxide, in particular paper pulp production sites. In practice ~he hydrogen peroxide employed is always delivered to the processing unit in the form of a concentrated aqueous solution, for example of 50 to 70 ~ by weight, by tanker or by container. This method of supplying hydrogen peroxide has numerous disadvantages, especially sa~ety problems linked with the many operations of unloading the concentrated solutions of hydrogen peroxide and costs associated with conveying it and with diluting it to the working concentration on the processing unit.
The applicant has envisaged the production of hydrogen peroxide in less highly concentrated aqueous solution on the processing unit on the industrial site itself. However, most o~ the sites operate virtually continuously throughout the year, o~ten at least 360 days per year and do not permit the interruption of the supply of hydrogen peroxide. Such an interruption is liable to take place, for example during the operations of maintenance of the hydrogen peroxide production plant.
The aim of the invention is to permit an uninterrupted feeding of the processing unit with hydrogen peroxide while allowing the usual maintenance operations of the feeding plant.
To this end the subject-matter of the invention is a plant for feeding hydrogen peroxide to a processing unit on an industrial site, characterized in that it includes a main plant for producing hydrogen peroxide at a working concentration, arranged on the .
The present invention relates to a plant for feeding hydrogen peroxide to a processing unit on an industrial site.
It applies in particular to the feed of hydrogen peroxide to a unit for bleaching paper pulp on a paper production site.
Many industrial sites consume large quantities of hydrogen peroxide, in particular paper pulp production sites. In practice ~he hydrogen peroxide employed is always delivered to the processing unit in the form of a concentrated aqueous solution, for example of 50 to 70 ~ by weight, by tanker or by container. This method of supplying hydrogen peroxide has numerous disadvantages, especially sa~ety problems linked with the many operations of unloading the concentrated solutions of hydrogen peroxide and costs associated with conveying it and with diluting it to the working concentration on the processing unit.
The applicant has envisaged the production of hydrogen peroxide in less highly concentrated aqueous solution on the processing unit on the industrial site itself. However, most o~ the sites operate virtually continuously throughout the year, o~ten at least 360 days per year and do not permit the interruption of the supply of hydrogen peroxide. Such an interruption is liable to take place, for example during the operations of maintenance of the hydrogen peroxide production plant.
The aim of the invention is to permit an uninterrupted feeding of the processing unit with hydrogen peroxide while allowing the usual maintenance operations of the feeding plant.
To this end the subject-matter of the invention is a plant for feeding hydrogen peroxide to a processing unit on an industrial site, characterized in that it includes a main plant for producing hydrogen peroxide at a working concentration, arranged on the .
actual site o~ the processing unit, and a backup plant intended to feed the processing unit in the event of stoppage of the main plant, comprising a backup reserve of hydrogen peroxide at a storage concentration higher than the working concentration and means for diluting the stored hydrogen peroxide which are connected between the reserve and the processing unit and which allow the concentration of stored hydrogen peroxide to be reduced to the working concentration.
10According to other characteristics of the nventlon: _ - the backup plant additionally comprises means for in~ecting a stabilizer into the dilute hydrogen peroxide;
15- the working concentration of the hydrogen peroxide is between 5 and 15 ~ by weight;
- the concentration of the hydrogen peroxide in the reserve is between 50 and 70 ~ by weight;
- the weight of the volume of the hydrogen 20peroxide in the reserve is between 100 and 200 metric tons;
- the main production plant is of the type using an anthraquinone process ~or the production o~
hydrogen peroxide;
25- the processing unit is a unit for bleaching paper pulp on a paper production site.
The invention will be understood better on reading the description which is to follow and which is given solely by way of example, for the understanding of which re~erence will be made to the drawings, in which:
- Figure 1 is a synoptic diagram of a plant for feeding hydrogen peroxide according to the invention;
- Figure 2 is a diagrammatic view of a main plant for the production of hydrogen peroxide, integrated into the plant of Figure 1, according to a preferred embodiment.
CA 022l4049 l997-08-27 A plant 10 ~or ~eeding hydrogen peroxide to a processing unit 12 on an industrial site has been shown in Figure 1.
This processing unit 12 is, ~or example, a unit ~or bleaching paper pulp o~ a paper production plant or site.
The plant 10 includes a main plant 14 for producing hydrogen peroxide arranged on the actual site o~ the processing unit 12.
The main plant 14 iS interLded to produce hydrogen peroxide at a relatively low working concentration which is preEerably between 5 and 15 ~ by weight.
The plant 10 for ~eeding hydrogen peroxide also comprises a backup plant 16 intended to ~eed the processing unit 12 in the event o~ stoppage o~ the main plant 14.
The backup plant 16 comprises a reserve oi~
backup hydrogen peroxide 18 and means 20 for diluting stored hydrogen peroxide oE known type. These means oi~
dilution 20 are connected between the reserve 18 and the processing unit 12 through the intermediacy o~ an upstream conduit 22 and a downstream conduit 24.
The hydrogen peroxide stored in the reserve 18 iS o~ the type usually supplied on the market. The hydrogen peroxide in the reserve has a concentration that is higher than the working concentration, pre~erably between 50 and 70 ~ by weight, and a volume the weight oi~ which is pre~erably between 100 and 200 metric tons, so as to make it possible to supply, ~or example, a conventional unit ~or bleaching paper pulp ~or approximately one week.
The main plant 14 iS connected to the processing plant 12 through the intermediacy o~ a conduit 26.
The conduit 24 downstream oE the reserve 18 and the conduit 26 downstream o~ the plant 14 are connected to the same conduit 28 Eor i~eeding the processing unit 12.
10According to other characteristics of the nventlon: _ - the backup plant additionally comprises means for in~ecting a stabilizer into the dilute hydrogen peroxide;
15- the working concentration of the hydrogen peroxide is between 5 and 15 ~ by weight;
- the concentration of the hydrogen peroxide in the reserve is between 50 and 70 ~ by weight;
- the weight of the volume of the hydrogen 20peroxide in the reserve is between 100 and 200 metric tons;
- the main production plant is of the type using an anthraquinone process ~or the production o~
hydrogen peroxide;
25- the processing unit is a unit for bleaching paper pulp on a paper production site.
The invention will be understood better on reading the description which is to follow and which is given solely by way of example, for the understanding of which re~erence will be made to the drawings, in which:
- Figure 1 is a synoptic diagram of a plant for feeding hydrogen peroxide according to the invention;
- Figure 2 is a diagrammatic view of a main plant for the production of hydrogen peroxide, integrated into the plant of Figure 1, according to a preferred embodiment.
CA 022l4049 l997-08-27 A plant 10 ~or ~eeding hydrogen peroxide to a processing unit 12 on an industrial site has been shown in Figure 1.
This processing unit 12 is, ~or example, a unit ~or bleaching paper pulp o~ a paper production plant or site.
The plant 10 includes a main plant 14 for producing hydrogen peroxide arranged on the actual site o~ the processing unit 12.
The main plant 14 iS interLded to produce hydrogen peroxide at a relatively low working concentration which is preEerably between 5 and 15 ~ by weight.
The plant 10 for ~eeding hydrogen peroxide also comprises a backup plant 16 intended to ~eed the processing unit 12 in the event o~ stoppage o~ the main plant 14.
The backup plant 16 comprises a reserve oi~
backup hydrogen peroxide 18 and means 20 for diluting stored hydrogen peroxide oE known type. These means oi~
dilution 20 are connected between the reserve 18 and the processing unit 12 through the intermediacy o~ an upstream conduit 22 and a downstream conduit 24.
The hydrogen peroxide stored in the reserve 18 iS o~ the type usually supplied on the market. The hydrogen peroxide in the reserve has a concentration that is higher than the working concentration, pre~erably between 50 and 70 ~ by weight, and a volume the weight oi~ which is pre~erably between 100 and 200 metric tons, so as to make it possible to supply, ~or example, a conventional unit ~or bleaching paper pulp ~or approximately one week.
The main plant 14 iS connected to the processing plant 12 through the intermediacy o~ a conduit 26.
The conduit 24 downstream oE the reserve 18 and the conduit 26 downstream o~ the plant 14 are connected to the same conduit 28 Eor i~eeding the processing unit 12.
Valves 30, 32 make it possible to isolate, respectively, the main plant 14 and the backup plant 18 from the processing unit 12.
The general flow direction of the fluids is shown by arrows in Figure 1 The operation of the plant for feeding hydrogen peroxide according to the invention can be implemented according to the manner described below.
Hydrogen peroxide has [sic] the desired working concentration is usually supplied directly to the processing unit by the main production plant 14. IP
this case the latter plant is connected to the processing unit 12 by opening the valve 30 while the reserve 18 is isolated from the processing unit 12 by closing the valve 32.
When the main plant 14 is stopped, especially ~or performing maintenance operations thereon, this plant is isolated from the processing unit 32 [sic] by closing the valve 30, the feeding of hydrogen peroxide to the unit 12 being done by the reserve 18 after opening the valve 32.
The concentration of the stored hydrogen peroxide is reduced by virtue of the means o~ dilution 20, to obtain . the working concentration normally supplied by the main production plant 14.
The backup plant 16 preferably comprises means 34 for injecting into the dilute hydrogen peroxide a stabilizer o~ a known type, chosen, for example, from carboxylic, aminomethylenecarboxylic, phosphonic and aminomethylenephosphonic compounds, in particular ethylenediaminetetraacetic acid (EDTA) or its salts, diethylenetriaminepentaacetic acid (DTPA) or its salts, polyacrylic acids, diethylenetriaminepentamethylene-phosphonic acid or its salts, 1,2-diamino-N,N,N'N'-tetramethylenephosphonic acid or its salts and hydroxy-ethylbismethylenephosphonic acid or its salts.
The stabilizer makes it possible to avoid the decomposition of the hydrogen peroxide to a relatively - low concentration until the injection of this hydrogen peroxide into the processing unit 12.
The main plant 14 for the production of hydrogen peroxide is preferably of the type employing an anthraquinone process. A plant of this type is shown in Figure 2.
The production plant 14 in Figure 2 includes three main units of equipment in the form of columns: a catalytic hydrogenator 101, a countercurrent oxidizer 102 and a water extractor 103. It also comprises many item~s of equipment associated with these three units of equipment, only some of which have been shown: a supercharger-condenser unit 104 for recirculating the gaseous mixture containing hydrogen, associated with the hydrogenator; a filter 106, a pump 107, a heat exchanger 108, a water cooler 109, a head condenser 110 and an air compressor 111 which are associated with the oxidizer; a conduit 112, as short as possible, connecting the base of the oxidizer 102 to that of the extractor 103; and a coalescer I14 and a pump 115 for recycling the working solution.
Also shown in Figure 2 iS a conduit 116 for feeding the hydrogenator with make-up hydrogen, a conduit 117 for feeding air to the compressor 111, a conduit 118 for feeding the extractor 103 with demineralized water, a hydrogen peroxide output conduit 119, which starts from the base of the extractor 103 and ends at the processing unit 12 which consumes hydrogen peroxide at the same concentration, and a conduit 121 for recycling the working solution. The conduit 119 is connected to the conduit 26.
The plant for producing hydrogen peroxide includes many items of equipment which are well known in the art and are not shown, such as means for regenerating decomposed products of the working solution, for using the catalyst, for recovering solvent, and the like.
In operation, the working solution, consisting of at least one anthraquinone derivative and at least =
Wo 96/26897 6 PCT/FR96/00244 one organic solvent, is introduced at the base of the hydrogenator 101 via the recycling conduit 121 connected to the delivery of the pump 115, 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 supercharger-condenser unit 104 and, on the other hand, of make-up hydrogen delivered via the conduit 116.
The working solution is thus partially reduced.
The reduced solution--drawn ~rom-~ ~She base of the hydrogenator by the pump 107 via the filter 106 therefore contains hydroquinone derivatives (for example 80 ~ o~ tetrahydroanthrahydroquinone and 20 of anthrahydroquinone).
The anthraquinone derivative constituent of the working solution is preferably chosen from 2-alkyl-9,10-anthraquinones in which the alkyl substituent contains from 1 to 5 carbon atoms, such as the methyl, ethyl, sec-butyl, tert-butyl and tert-amyl radicals, as well as the corresponding 5,6,7,8-tetrahydro deriva-tives, or from 9,10-dialkylanthraquinones in which the alkyl substituents, which are identical or dif~erent, contain from 1 to 5 carbon atoms, such as the methyl, ethyl, tert-butyl radicals, for example 1,3-dimethyl, 1,4-dimethyl, 2,3-dimethyl, 2,7-dimethyl, 1,3-diethyl, 2,7-di-tert-butyl, 2-ethyl-6-tert-butyl and the corresponding 5,6,7,8-tetrahydro derivatives. The organic solvent constituent of the working solution is preferably a mixture o~ a nonpolar compound and of a polar compound. The nonpolar compound is preferably chosen from petroleum cuts with a boiling point higher than 140~C containing predominantly aromatic hydrocarbons containing at least 9 carbon atoms, such as trimethylbenzene isomers, tetramethylbenzene isomers, tert-butylbenzene, methylnaphthalene isomers and dimethylnaphthalene isomers. The polar compound is preferably chosen from saturated alcohols preferably containing ~rom 7 to 11 carbon atoms, such as .
- diisobutylcarbinol, 3,5,5-trimethylhexanol, isohep-tanol, carboxylic acid esters such as methylcyclohexyl acetate marketed under the name o~ "Sextate", heptyl acetate, butyl benzoate, ethyl heptanoate, phosphoric acid esters such as tributyl phosphate, tri(2-ethylbutyl) phosphate, tri(2-ethylhexyl) phosphate, tri(n-octyl) phosphate, and tetrasubstituted ureas such as tetra-n-butylurea.
"Hydrogen peroxide equivalent/' will hereina~ter be understood to mean the quantity o~ hydrogen peroxide, expressed in grams, which one liter o~
~ working solution is capable o~ supplying at the end o~
the oxidation stage i~ the yield o~ this stage in the oxidizer 102 is 100 ~. This potential mass concentration o~ peroxide corresponds to a molar concentration which is equal to the molar concentration o~ all the reoxidizable anthrahydroquinone ~orms in the working solution. It depends, on the one hand, on the concentration o~ anthraquinone ~orms o~ the working solution at the start and, on the other hand, on the hydrogenation conditions in 101.
In the present case the hydrogenation is per~ormed at a temperature o~ between 50 and 70~C, with a pressure in the gas headspace o~ the hydrogenator (pressure which controls the ~low rate o~ hydrogen) approximately ~rom 0.8 to 1.5 bar and the hydrogen peroxide equivalent is adjusted to a value o~
approximately between 7 and 9 g/l, by adjusting the residence time in the hydrogenator ~or a given concentration o~ anthraquinone ~orms.
The reduced working solution drawn ~rom the hydrogenator is ~iltered at 106 to remove any trace o~
catalyst and then cooled in 108 and then in 109 to a temperature o~ the order o~ 35 to 40~C. The pressure in the gas headspace o~ the oxidizer is maintained at a value o~ between 2 and 4 bars. The reduced working solution is thus oxidized in 102, the head ~luid of the oxidizer being partially condensed in 110.
wo 96/26897 8 PCT/FR96/00244 - The hydrogen peroxide ~ormed by the oxidation reaction is drawn ~rom the base o~ the oxidizer in a quantity equal to the product o~ the abovementioned hydrogen peroxide equivalent times the yield o~ the oxidizer, as a mixture with the working solution which is oxidized again. This liquid is conveyed directly via the conduit 112, by virtue o~ the propelling pressure dif~erence to the base o~ the extractor 103, which operates slightly above the atmospheric pressure. A
liquid-liquid extraction is per~ormed in the extractor by means o~ the demineralized water introduced at the top of the extractor.
A water-hydrogen peroxide solution is drawn ~rom the base o~ the latter, and its hydrogen peroxide concentration is adjusted to the value necessary ~or its direct use in the processing unit 12.
The working solution separated ~rom the hydrogen peroxide is drawn ~rom the top o~ the extractor 103, ~reed ~rom the droplets o~ aqueous phase which it has entrained in the coalescer 114, and then conveyed by the pump 115 to the heat exchanger 108, in which it is warmed up and, ~rom there, recycled to the base o~ the hydrogenator 101.
The oxidizer 102 comprises an outer enclosure containing an organized packing or simple per~orated trays or trays o~ the distillation tray type, that is to say each with a liquid seal, ori~ices ~or bubbling gas rising through this seal and liquid downcomers ~rom one tray to the next, or else a combination o~ an organized packing and o~ such trays.
The invention comprises numerous advantages.
The plant according to the invention makes it possible to ~eed a processing unit with hydrogen peroxide without interruption, while permitting plant maintenance operations. Thus, when the main plant ~or the production of hydrogen peroxide is stopped, the backup plant ~eeds the processing unit instead o~ the main plant.
WO 96/26897 9 P~T/FR96/00244 The dimensions of the reserve 18 are relatively small, given the high concentration of the hydrogen peroxide stored therein.
The plant according to the invention makes it possible to circumvent the disadvantages due to the supply of hydrogen peroxide in the form of concentrated aqueous solution, in particular the risks associated with the unloading operations.
The general flow direction of the fluids is shown by arrows in Figure 1 The operation of the plant for feeding hydrogen peroxide according to the invention can be implemented according to the manner described below.
Hydrogen peroxide has [sic] the desired working concentration is usually supplied directly to the processing unit by the main production plant 14. IP
this case the latter plant is connected to the processing unit 12 by opening the valve 30 while the reserve 18 is isolated from the processing unit 12 by closing the valve 32.
When the main plant 14 is stopped, especially ~or performing maintenance operations thereon, this plant is isolated from the processing unit 32 [sic] by closing the valve 30, the feeding of hydrogen peroxide to the unit 12 being done by the reserve 18 after opening the valve 32.
The concentration of the stored hydrogen peroxide is reduced by virtue of the means o~ dilution 20, to obtain . the working concentration normally supplied by the main production plant 14.
The backup plant 16 preferably comprises means 34 for injecting into the dilute hydrogen peroxide a stabilizer o~ a known type, chosen, for example, from carboxylic, aminomethylenecarboxylic, phosphonic and aminomethylenephosphonic compounds, in particular ethylenediaminetetraacetic acid (EDTA) or its salts, diethylenetriaminepentaacetic acid (DTPA) or its salts, polyacrylic acids, diethylenetriaminepentamethylene-phosphonic acid or its salts, 1,2-diamino-N,N,N'N'-tetramethylenephosphonic acid or its salts and hydroxy-ethylbismethylenephosphonic acid or its salts.
The stabilizer makes it possible to avoid the decomposition of the hydrogen peroxide to a relatively - low concentration until the injection of this hydrogen peroxide into the processing unit 12.
The main plant 14 for the production of hydrogen peroxide is preferably of the type employing an anthraquinone process. A plant of this type is shown in Figure 2.
The production plant 14 in Figure 2 includes three main units of equipment in the form of columns: a catalytic hydrogenator 101, a countercurrent oxidizer 102 and a water extractor 103. It also comprises many item~s of equipment associated with these three units of equipment, only some of which have been shown: a supercharger-condenser unit 104 for recirculating the gaseous mixture containing hydrogen, associated with the hydrogenator; a filter 106, a pump 107, a heat exchanger 108, a water cooler 109, a head condenser 110 and an air compressor 111 which are associated with the oxidizer; a conduit 112, as short as possible, connecting the base of the oxidizer 102 to that of the extractor 103; and a coalescer I14 and a pump 115 for recycling the working solution.
Also shown in Figure 2 iS a conduit 116 for feeding the hydrogenator with make-up hydrogen, a conduit 117 for feeding air to the compressor 111, a conduit 118 for feeding the extractor 103 with demineralized water, a hydrogen peroxide output conduit 119, which starts from the base of the extractor 103 and ends at the processing unit 12 which consumes hydrogen peroxide at the same concentration, and a conduit 121 for recycling the working solution. The conduit 119 is connected to the conduit 26.
The plant for producing hydrogen peroxide includes many items of equipment which are well known in the art and are not shown, such as means for regenerating decomposed products of the working solution, for using the catalyst, for recovering solvent, and the like.
In operation, the working solution, consisting of at least one anthraquinone derivative and at least =
Wo 96/26897 6 PCT/FR96/00244 one organic solvent, is introduced at the base of the hydrogenator 101 via the recycling conduit 121 connected to the delivery of the pump 115, 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 supercharger-condenser unit 104 and, on the other hand, of make-up hydrogen delivered via the conduit 116.
The working solution is thus partially reduced.
The reduced solution--drawn ~rom-~ ~She base of the hydrogenator by the pump 107 via the filter 106 therefore contains hydroquinone derivatives (for example 80 ~ o~ tetrahydroanthrahydroquinone and 20 of anthrahydroquinone).
The anthraquinone derivative constituent of the working solution is preferably chosen from 2-alkyl-9,10-anthraquinones in which the alkyl substituent contains from 1 to 5 carbon atoms, such as the methyl, ethyl, sec-butyl, tert-butyl and tert-amyl radicals, as well as the corresponding 5,6,7,8-tetrahydro deriva-tives, or from 9,10-dialkylanthraquinones in which the alkyl substituents, which are identical or dif~erent, contain from 1 to 5 carbon atoms, such as the methyl, ethyl, tert-butyl radicals, for example 1,3-dimethyl, 1,4-dimethyl, 2,3-dimethyl, 2,7-dimethyl, 1,3-diethyl, 2,7-di-tert-butyl, 2-ethyl-6-tert-butyl and the corresponding 5,6,7,8-tetrahydro derivatives. The organic solvent constituent of the working solution is preferably a mixture o~ a nonpolar compound and of a polar compound. The nonpolar compound is preferably chosen from petroleum cuts with a boiling point higher than 140~C containing predominantly aromatic hydrocarbons containing at least 9 carbon atoms, such as trimethylbenzene isomers, tetramethylbenzene isomers, tert-butylbenzene, methylnaphthalene isomers and dimethylnaphthalene isomers. The polar compound is preferably chosen from saturated alcohols preferably containing ~rom 7 to 11 carbon atoms, such as .
- diisobutylcarbinol, 3,5,5-trimethylhexanol, isohep-tanol, carboxylic acid esters such as methylcyclohexyl acetate marketed under the name o~ "Sextate", heptyl acetate, butyl benzoate, ethyl heptanoate, phosphoric acid esters such as tributyl phosphate, tri(2-ethylbutyl) phosphate, tri(2-ethylhexyl) phosphate, tri(n-octyl) phosphate, and tetrasubstituted ureas such as tetra-n-butylurea.
"Hydrogen peroxide equivalent/' will hereina~ter be understood to mean the quantity o~ hydrogen peroxide, expressed in grams, which one liter o~
~ working solution is capable o~ supplying at the end o~
the oxidation stage i~ the yield o~ this stage in the oxidizer 102 is 100 ~. This potential mass concentration o~ peroxide corresponds to a molar concentration which is equal to the molar concentration o~ all the reoxidizable anthrahydroquinone ~orms in the working solution. It depends, on the one hand, on the concentration o~ anthraquinone ~orms o~ the working solution at the start and, on the other hand, on the hydrogenation conditions in 101.
In the present case the hydrogenation is per~ormed at a temperature o~ between 50 and 70~C, with a pressure in the gas headspace o~ the hydrogenator (pressure which controls the ~low rate o~ hydrogen) approximately ~rom 0.8 to 1.5 bar and the hydrogen peroxide equivalent is adjusted to a value o~
approximately between 7 and 9 g/l, by adjusting the residence time in the hydrogenator ~or a given concentration o~ anthraquinone ~orms.
The reduced working solution drawn ~rom the hydrogenator is ~iltered at 106 to remove any trace o~
catalyst and then cooled in 108 and then in 109 to a temperature o~ the order o~ 35 to 40~C. The pressure in the gas headspace o~ the oxidizer is maintained at a value o~ between 2 and 4 bars. The reduced working solution is thus oxidized in 102, the head ~luid of the oxidizer being partially condensed in 110.
wo 96/26897 8 PCT/FR96/00244 - The hydrogen peroxide ~ormed by the oxidation reaction is drawn ~rom the base o~ the oxidizer in a quantity equal to the product o~ the abovementioned hydrogen peroxide equivalent times the yield o~ the oxidizer, as a mixture with the working solution which is oxidized again. This liquid is conveyed directly via the conduit 112, by virtue o~ the propelling pressure dif~erence to the base o~ the extractor 103, which operates slightly above the atmospheric pressure. A
liquid-liquid extraction is per~ormed in the extractor by means o~ the demineralized water introduced at the top of the extractor.
A water-hydrogen peroxide solution is drawn ~rom the base o~ the latter, and its hydrogen peroxide concentration is adjusted to the value necessary ~or its direct use in the processing unit 12.
The working solution separated ~rom the hydrogen peroxide is drawn ~rom the top o~ the extractor 103, ~reed ~rom the droplets o~ aqueous phase which it has entrained in the coalescer 114, and then conveyed by the pump 115 to the heat exchanger 108, in which it is warmed up and, ~rom there, recycled to the base o~ the hydrogenator 101.
The oxidizer 102 comprises an outer enclosure containing an organized packing or simple per~orated trays or trays o~ the distillation tray type, that is to say each with a liquid seal, ori~ices ~or bubbling gas rising through this seal and liquid downcomers ~rom one tray to the next, or else a combination o~ an organized packing and o~ such trays.
The invention comprises numerous advantages.
The plant according to the invention makes it possible to ~eed a processing unit with hydrogen peroxide without interruption, while permitting plant maintenance operations. Thus, when the main plant ~or the production of hydrogen peroxide is stopped, the backup plant ~eeds the processing unit instead o~ the main plant.
WO 96/26897 9 P~T/FR96/00244 The dimensions of the reserve 18 are relatively small, given the high concentration of the hydrogen peroxide stored therein.
The plant according to the invention makes it possible to circumvent the disadvantages due to the supply of hydrogen peroxide in the form of concentrated aqueous solution, in particular the risks associated with the unloading operations.
Claims (7)
1. Plant for feeding hydrogen peroxide to a processing unit (12) on an industrial site, characterized in that it includes a main plant (14) for producing hydrogen peroxide at a working concentration, arranged on the actual site of the processing unit (12), and a backup plant (16) intended to feed the processing unit (12) in the event of stoppage of the main plant (14), comprising a backup reserve (18) of hydrogen peroxide at a storage concentration higher than the working concentration and means for diluting the stored hydrogen peroxide which are connected between the reserve (18) and the processing unit (12) and which allow the concentration of stored hydrogen peroxide to be reduced to the working concentration.
2. Plant according to claim 1, characterized in that the backup plant (16) additionally comprises means (34) for injecting a stabilizer into the dilute hydrogen peroxide.
3. Plant according to claim 1 or 2, characterized in that the working concentration of the hydrogen peroxide is between 5 and 15 % by weight.
4. Plant according to any one of the preceding claims, characterized in that the concentration of the hydrogen peroxide in the reserve is between 50 and 70 %
by weight.
by weight.
5. Plant according to any one of the preceding claims, characterized in that the weight of the volume of the hydrogen peroxide in the reserve is between 100 and 200 metric tons.
6. Plant according to any one of the preceding claims, characterized in that the main production plant (14) is of the type using an anthraquinone process for the production of hydrogen peroxide.
7. Plant according to any one of the preceding claims, characterized in that the processing unit (12) is a unit for bleaching paper pulp on a paper production site.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9502319A FR2730984B1 (en) | 1995-02-28 | 1995-02-28 | INSTALLATION FOR SUPPLYING HYDROGEN PEROXIDE TO A TREATMENT UNIT OF AN INDUSTRIAL SITE |
| FR95/02319 | 1995-02-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2214049A1 true CA2214049A1 (en) | 1996-09-06 |
Family
ID=9476581
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002214049A Abandoned CA2214049A1 (en) | 1995-02-28 | 1996-02-14 | Apparatus for feeding hydrogen peroxide to a processing unit in an industrial facility |
Country Status (12)
| Country | Link |
|---|---|
| EP (1) | EP0812298A1 (en) |
| JP (1) | JPH11500996A (en) |
| CN (1) | CN1176629A (en) |
| AU (1) | AU4834996A (en) |
| BR (1) | BR9607432A (en) |
| CA (1) | CA2214049A1 (en) |
| CO (1) | CO4560352A1 (en) |
| FI (1) | FI973511A (en) |
| FR (1) | FR2730984B1 (en) |
| MY (1) | MY132346A (en) |
| TW (1) | TW302410B (en) |
| WO (1) | WO1996026897A1 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993021106A1 (en) * | 1992-04-15 | 1993-10-28 | A. Ahlstrom Corporation | Production of bleaching chemicals on site at a pulp mill |
| SE9301940L (en) * | 1992-06-10 | 1993-12-11 | Ahlstroem Oy | Preparation of bleaching chemicals for cellulose pulp |
-
1995
- 1995-02-28 FR FR9502319A patent/FR2730984B1/en not_active Expired - Fee Related
-
1996
- 1996-02-14 BR BR9607432A patent/BR9607432A/en active Search and Examination
- 1996-02-14 WO PCT/FR1996/000244 patent/WO1996026897A1/en not_active Application Discontinuation
- 1996-02-14 CA CA002214049A patent/CA2214049A1/en not_active Abandoned
- 1996-02-14 EP EP96904142A patent/EP0812298A1/en not_active Withdrawn
- 1996-02-14 AU AU48349/96A patent/AU4834996A/en not_active Abandoned
- 1996-02-14 JP JP8526053A patent/JPH11500996A/en active Pending
- 1996-02-14 CN CN96192215.XA patent/CN1176629A/en active Pending
- 1996-02-27 MY MYPI96000702A patent/MY132346A/en unknown
- 1996-02-27 CO CO96009194A patent/CO4560352A1/en unknown
- 1996-04-01 TW TW085103797A patent/TW302410B/zh active
-
1997
- 1997-08-27 FI FI973511A patent/FI973511A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| MY132346A (en) | 2007-10-31 |
| TW302410B (en) | 1997-04-11 |
| JPH11500996A (en) | 1999-01-26 |
| FI973511A (en) | 1997-10-16 |
| FI973511A0 (en) | 1997-08-27 |
| EP0812298A1 (en) | 1997-12-17 |
| AU4834996A (en) | 1996-09-18 |
| CN1176629A (en) | 1998-03-18 |
| FR2730984A1 (en) | 1996-08-30 |
| FR2730984B1 (en) | 1997-05-23 |
| BR9607432A (en) | 1998-05-26 |
| CO4560352A1 (en) | 1998-02-10 |
| WO1996026897A1 (en) | 1996-09-06 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |