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EP2592186A1 - Procédé de réduction en pâte kraft - Google Patents

Procédé de réduction en pâte kraft Download PDF

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Publication number
EP2592186A1
EP2592186A1 EP11188279.1A EP11188279A EP2592186A1 EP 2592186 A1 EP2592186 A1 EP 2592186A1 EP 11188279 A EP11188279 A EP 11188279A EP 2592186 A1 EP2592186 A1 EP 2592186A1
Authority
EP
European Patent Office
Prior art keywords
liquor
treatment
vessel
process according
wood
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP11188279.1A
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German (de)
English (en)
Inventor
Johannes Bogren
Henric Brage
Espen Ribe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SODRA CELL AB
Original Assignee
SODRA CELL AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by SODRA CELL AB filed Critical SODRA CELL AB
Priority to EP11188279.1A priority Critical patent/EP2592186A1/fr
Priority to PCT/EP2012/072120 priority patent/WO2013068453A2/fr
Publication of EP2592186A1 publication Critical patent/EP2592186A1/fr
Withdrawn legal-status Critical Current

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    • 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
    • D21C11/00—Regeneration of pulp liquors or effluent waste waters
    • D21C11/12—Combustion of pulp liquors
    • 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
    • D21C11/00—Regeneration of pulp liquors or effluent waste waters
    • D21C11/0064—Aspects concerning the production and the treatment of green and white liquors, e.g. causticizing green liquor
    • D21C11/0071—Treatment of green or white liquors with gases, e.g. with carbon dioxide for carbonation; Expulsion of gaseous compounds, e.g. hydrogen sulfide, from these liquors by this treatment (stripping); Optional separation of solid compounds formed in the liquors by this treatment
    • 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
    • D21C11/00—Regeneration of pulp liquors or effluent waste waters
    • D21C11/04—Regeneration of pulp liquors or effluent waste waters of alkali lye

Definitions

  • the present invention relates to a process for producing substantially pure hydrogen sulphide (H 2 S).
  • the present invention also relates to a process for producing a new pre-treatment mixture, which is to be used in a pre-treatment step before cooking in processes for producing kraft pulp.
  • the present invention also relates to a process for producing kraft pulp, said process comprising the above mentioned processes.
  • H 2 S is, as mentioned above, a very toxic and explosive gas and therefore has to be handled with care.
  • US 3560329 discloses that H 2 S can be obtained from black liquor, however the disclosed process has problems with fouling which is caused by non-soluble lignin in the evaporation train.
  • CA 923255 also discloses a process for obtaining H 2 S, wherein the black liquor is treated with flue gases and thereafter the obtained gas mixture is purified by using an absorption/desorption process to purify the gas mixture.
  • the problem with said process is that also solid substances are obtained, which requires expensive and advance equipment. Furthermore, this process also requires the addition of additional substances, which makes the process more complicated.
  • H 2 S can be made from green liquor by formation from hydrogen sulphide ions.
  • available processes provide products comprising large amounts of impurities and therefore large amounts of gas will be needed to obtain the desired yield of the pulp.
  • WO 2004/092478 discloses a method for the pre-treatment of chips that are fed to a kraft process, the method is characterized in that the chips before heating in a closed pre-treatment step are formed into a slurry with an acidic treatment fluid, after this the acidified chips are drained and then heated with a sulphide-rich alkali impregnation liquor and therefore H 2 S is formed locally.
  • the disadvantage with this process is the relative modest yield increase caused by the inefficient formation of H 2 S. Also, the process cannot be completed since suitable sulphide-rich liquors are not available in kraft mills of today.
  • A.R. Procter Pulp and Paper Canada Vol. 77, Nov 12/December 1976
  • US 3520 773 and US 3841962 discloses hydrogen sulphide pre-treatment of lignocellulosic materials in alkaline pulping processes.
  • the processes disclosed do not give as high pulping yield as when high pressure H 2 S is applied. Additionally, the processes are very complex and require many process steps, this makes the energy demand large, mainly because of the crystallization step.
  • the present invention besides from overcoming the problems mentioned above, also aims to fulfill these requirements.
  • the present invention provides a process for producing substantially pure hydrogen sulphide (H 2 S).
  • the substantially pure H 2 S is, according to the present invention, in gaseous form.
  • the advantage of having a substantially pure H 2 S is that the process equipment used in the kraft pulp mill will be cheaper and simpler as the total pressure can be minimized. Also, with said process, it will be possible to have a closed system for producing pulp, i.e. in the sense that almost all chemical substances used are recycled so there will be almost no emissions to the environment, which will provide a safer environment within the mill.
  • another advantage of having the present invention within a kraft pulp mill is that it will be much easier to control the total process system compared to a case when the H 2 S is formed in-situ.
  • the present invention is also providing a process for producing pre-treatment mixture and the use of said pre-treatment mixture in a process for pre-treating wood before the kraft cooking process.
  • the wood can be in the form of chips, shives, saw dust etc.
  • the pre-treatment mixture has a high content of H 2 S and a high buffering capacity.
  • said process will be very effective due to the high partial pressure of H 2 S and the sufficiently high reaction temperature, i.e. a temperature in the range of from 100 to 180 °C, such as from 120 - 160 °C, such as 140 °C.
  • the process for producing the pre-treatment mixture uses an efficient and short recirculation process of pre-treatment mixture which will provide a high concentration of H 2 S in the recirculated liquor and therefore reduce the charge of fresh H 2 S (g) to the pre-treatment process, which in turn will reduce the size of the needed stripper for H 2 S generation, and thereby reduce the costs.
  • the present invention will also provide a large scale kraft process comprising the two processes mentioned above, said process has a cheap and simple equipment as this process only needs one "main process equipment” when forming H 2 S (g).
  • the present invention provides a process integrating the processes disclosed above for producing pulp, more specifically kraft pulp.
  • the obtained pulp is provided in excellent yield and also has good pulp properties.
  • kraft process and "sulphate process” are used interchangeably within the present application and describes a technology for chemically treating wood in order to liberate fibers from each other.
  • the process entails treatment of wood, e.g. in the form of chips, with a mixture of sodium hydroxide and sodium hydrosulphide, known as white liquor, which degrades lignin and makes it soluble.
  • hydroxide and "dihydrogen sulphide”, are used interchangeably herein to denote the chemical compound with the formula "H 2 S”. It is a colorless, very poisonous and flammable gas with the characteristic foul odor of expired eggs perceptible at concentrations as low as 0.00047 parts per million.
  • green liquor as used herein is intended to mean the dissolved melt of sodium carbonate and sodium sulphide from the recovery boiler in the kraft process.
  • An example of a composition of a green liquor of a kraft mill is a composition comprising 3.36 mol/kg Na + , 0.20 mol/kg K + , 0.68 mol/kg OH - , 0.60 mol/kg HS - , and 1.13 mol/kg CO 3 2- .
  • sulphide-lean green liquor as used herein is intended to mean green liquor comprising almost no sulphur, such as less than 10 % of the originating sulphur content of the green liquor, such as less than 9, 8, 7, 6, 5, 4, 3, 2 or 1% of the originating sulphur content of the green liquor.
  • short recirculation as used herein is intended to include the internal loop of H 2 S containing impregnation liquor around the H 2 S pre-treatment process step. It includes the pre-treatment vessel, piping and the impregnation liquor storage vessel.
  • the term "closed system” is intended to include a system which has almost no emissions of H 2 S to the surroundings. Further, all surplus H 2 S from the chip impregnation is collected and re-circulated in the short recirculation. This has both the advantage of lower emissions to the environment and substantially lower chemical costs.
  • stripper as used herein is intended to mean a kind of distillation column wherein a gas is desorbed from a liquid by using a stripping agent, example of a stripping agent is steam (vapour). Stripping is a physical separation process where one or more components are removed from a liquid stream by a vapor stream
  • main process equipment is used for equipment in which a process step is conducted.
  • the main process equipment includes process parts such as pumps, mixers, heat exchangers etc.
  • substantially pure H 2 S as used herein is intended to mean H 2 S gas consisting less than 15 weight% impurities, such as less than 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 weight% impurities.
  • the impurities are for example carbon dioxide and steam.
  • Example of a substantially pure H 2 S is a H 2 S gas consisting of 90 weight% H 2 S and 10 weight% CO 2 .
  • TTA Total Titratable Alkali and is the sum of the concentration of all bases present in liquor which can be titrated with strong acid (in total 3 inflexion points).
  • bases NaOH, Na 2 S and Na 2 CO 3 (as NaOH) measured by titration according to SCAN 30:85.
  • SCAN is an international standard for processes/analytical methods used within the technical field.
  • EA Effective Alkali and is the concentration of strongly alkaline constituents determined by titration of a sample of white or green liquor. It is determined by titration with strong acid to the first inflexion point in the procedure SCAN 30:85. In practise this is considered to be the concentration of hydroxide ions.
  • recirculated liquor is intended to mean the used pre-treatment liquor prior to the make-up charge of green liquor and H 2 S.
  • bar(a) means the absolute pressure in bar.
  • the present invention relates to a process for producing substantially pure H 2 S, wherein said process comprises the steps of:
  • the steps a)-f) will result in gas formation and separation of the gas from the liquors.
  • the separated gas from a)-f) may be treated in a condenser in step g) in order to obtain substantially pure H 2 S (g) in step h).
  • treating means mixing, injection etc., as there are different methods to obtain the result of each step, e.g. in step a) treating means mixing.
  • step a) is performed at a temperature of from 60 to 95°C, such as from 80 to 85°C.
  • the pressure of the vessel is from 0.05 to 1 bar(a), such as from 0.15 to 0.3 bar(a).
  • the temperature of the vessel is from 25 to 95°C.
  • the ratio of steam flow and H 2 S production flow is from 10 to 40, such as from 15 to 20.
  • said green liquor is obtained from the recovery cycle of the kraft pulping process and wherein said green liquor comprises a molar ratio of Na 2 CO 3 /Na 2 S of ⁇ 1.5.
  • a distillation column is used as a vessel, such as a stripper.
  • the acid of step a) and/or step e) is carbon dioxide.
  • FIG. 1 shows a schematic representation of the process of the present invention for producing substantially pure H 2 S (g).
  • Part of the green liquor flow of the pulp mill is treated with an acid, such as carbon dioxide.
  • the acid neutralizes the hydroxide ions in the green liquor and alkali-lean green liquor is formed.
  • the alkali-lean green liquor is introduced to the main process equipment, preferably a stripper with a packed bed.
  • a sulphur-lean green liquor is also added, which is formed from a treatment of the bottom product of the stripper with an acid such as carbon dioxide.
  • the two liquors will react and H 2 S (g) will be obtained.
  • the obtained H 2 S (g) will be stripped of using a stripping agent, such steam.
  • the gaseous product will exit the stripper and the substantially pure H 2 S will be obtained after removal of steam.
  • the substantially pure H 2 S will also consist of CO 2 (g) and H 2 O (g).
  • the stripper is preferably operated in such a way that the concentration of CO 2 (g) is minimized.
  • the process of producing substantially pure H 2 S is, according to the present invention, preferably performed using a stripper as equipment.
  • a stripper as equipment
  • person skilled in the art are aware of other suitable equipment.
  • the driving force of the stripper is the difference in partial pressure in the vapor phase and the amount of substances in the liquid phase.
  • simultaneous chemical reactions will take place in the stripper, i.e. a reactive distillation.
  • stripping of H 2 S is more effective at lower total pressures because this reduces the partial pressure of H 2 S in the stripper.
  • a reduction of the total pressure enables a reduction in either stripping steam flow or the reflux flow of sulphide-lean green liquor.
  • the low pressure of the stripper also improves the safety as a leakage would not cause a hazardous environment outside the stripper. In this way, the zone in which pressurized H 2 S is handled can be minimized.
  • the reaction of the stripper is the following: NaHS + NaHCO 3 ⁇ Na 2 CO 3 + H 2 S (g).
  • the stripper has the following process data.
  • the obtained gas composition consists of about 90 % H 2 S and about 10 % CO 2 .
  • the stripper can be operated in many ways, as well known to a person skilled in the art.
  • the present invention also relates to a process for producing a pre-treatment mixture, said process comprises the steps of:
  • step i. and step ii. do not have to be carried out in any specific order, i.e. step ii. might be carried out before step i. and step i. might be carried out before step ii.. However, the lead time between said steps might be long.
  • the liquor of step i) has been used in earlier pre-treatment processes.
  • the obtained pre-treatment mixture comprises sulphur so that the total amount of sulphur is greater than 1 mol S/kg wood, such as greater than 1.5 mol S/kg wood.
  • said sulphur is in the form of HS - or H 2 S.
  • the pH of the recirculated liquor is in the range of from 5 to 9, such as from 6 to 8.
  • the total titratable alkali (TTA) of the pre-treatment liquor is from 1 to 10 %, such as from 3 to 6 %.
  • the temperature of the pre-treatment liquor is from 100-180°C, such as 130-160°C.
  • the present invention also relates to a process for the pre-treatment of wood wherein said wood is treated with the pre-treatment mixture produced as disclosed above.
  • the wood might be in the form of chips, shives, saw dust etc.
  • Figure 2 shows a schematic representation of the part of the present invention wherein the pre-treatment of wood with H 2 S prior to kraft cooking is taking place.
  • Wood is added to the pre-treatment vessel wherein the wood is treated with a buffer solution, which comprises recirculated buffer solution, green liquor and H 2 S.
  • a buffer solution which comprises recirculated buffer solution, green liquor and H 2 S.
  • the used pre-treatment liquor is displaced to the recirculation cycle (wherein a pre-treatment liquor storage vessel can be incorporated).
  • the treated wood thereafter undergoes kraft cooking (either in the pre-treatment vessel or in a separate digester).
  • the re-circulated pre-treatment liquor is rich in H 2 S (aq) and is re-used in subsequent pre-treatments after necessary make up of green liquor and H 2 S (g).
  • the present invention also relates to kraft processes comprising the processes of the present invention as disclosed above for producing high-yield kraft pulp.
  • Kraft processes are highly alkaline processes comprising NaOH and Na 2 S as the active chemicals in the cooking liquor. This is a difference compared to sulphite processes wherein SO 2 , water and a base cat-ion are used as cooking chemicals, example of a sulphite process is disclosed in e.g. SE383866 . Many different bases can be used in the sulphite process (Ca, Mg, Na and NH 4 ). The composition of the resulting spent cooking liquors and the corresponding regeneration of cooking chemicals therefore differ between sulphite and kraft processes.
  • the chemical recovery of used kraft cooking liquor starts with evaporation of water followed by incineration of organic material in a recovery boiler which also regenerates cooking chemicals in the form of a melt which mainly consists of Na 2 S and Na 2 CO 3 .
  • This melt is dissolved in weak liquor (water and some alkaline components) and clarified to give kraft green liquor .
  • Example of a green liquor composition is a composition comprising 80-100 g Na 2 CO 3 , 40-50 g Na 2 S, 3-6 g Na 2 SO 4 , 5-20 g NaOH and 5-10 g other dissolved Na compounds per litre (calculated as Na 2 O).
  • the green liquor is processed further to produce the white liquor used for cooking.
  • the "sulphite green liquor” from a sodium based process is very different from kraft green liquor. Even though the brown liquor (in analogy to black liquor for the kraft process) is burned in a kraft type furnace the resulting melt consisting of sodium sulphide and sodium carbonate is much richer in sulphur.
  • the kraft process according to the present invention can be used either for a continuous or a batch digester.
  • An example of such a process is a process comprising a pre-treatment of wood prior to kraft cooking with H 2 S in diluted kraft green liquor with a TTA of 2-8 % on wood and liquor to wood ratio of 3-8 kg/kg.
  • Example of such a process is shown in figure 3 .
  • the wood are pre-treated with the present pre-treatment mixture according to the present invention before they are fed into the sulphate cooking process as shown in figure 3 .
  • the wood material for example in the form of chips can be obtained according to methods known to a person skilled in the art.
  • the wood chips may also prior to said pre-treatment step be pre-treated with steam to improve the impregnation with pre-treatment liquor.
  • the pre-treatment liquor will be displaced to the pre-treatment liquor vessel by another liquor (batch case) or in the continuous case first displaced using counter-current washing in the pre-treatment vessel, and then pumped to the digester in a standard manner.
  • the present invention is based on the finding that it in order to be able to scale-up pre-treatment processes comprising H 2 S, it is important to have a substantially pure H 2 S and to reduce the amount of CO 2 , the reduction of CO 2 will also reduce the total pressure of the process at a constant partial pressure of H 2 S.
  • the CO 2 is reduced since the amount of added CO 2 will be minimised and the stripper should be operated in such a way that the equilibrium and kinetics favours the formation of H 2 S (g) and suppresses the formation of CO 2 (g) from present CO 3 2- .
  • FIG 3 the process system for producing high yield kraft pulp is schematically presented incorporating both production of substantially pure H 2 S (g) and the production of high yield pulp based on H 2 S pretreatment using this substantially pure H 2 S as a make-up chemical.
  • the present invention provides a process for producing kraft pulp, which has taken the whole process system of the kraft pulping process under consideration. Furthermore, the processes according to the present invention can be integrated into a large scale kraft pulping process without any need of additional process equipment installations (except those mentioned in the present invention. Also, the present invention relates to a process for producing substantially pure H 2 S and also to a kraft pre-treatment process, wherein the pre-treatment liquor is recirculated in a closed system. The pre-treatment liquor is rich in H 2 S due to unconsumed gas from earlier pre-treatments, and the need for fresh make-up H 2 S is therefore reduced.
  • the present invention is further illustrated by the non-limiting example below.
  • Pilot plant H 2 S-impregnation in diluted green liquor followed by kraft cooking
  • the temperature of the vessel was increased to 140°C during 15 minutes and H 2 S was allowed to react with the chips at 140°C for 40 minutes.
  • the free liquor in the digester was displaced through the digester top to the impregnation liquor vessel charging liquors from the bottom of the digester using the following sequence: a) make-up chemicals needed to retain correct strength of the impregnation liquor (this liquor was also displaced to the impregnation liquor vessel), b) water to make sure there would not be any cooking liquor transferred to the impregnation liquor vessel and c) cooking liquor to hydraulic fill the digester (21.5 % EA).
  • a mill scale process for recycling of pre-treatment liquor and charging of necessary make-up H 2 S can be achieved for batch digesters by using the process as disclosed in this example (the digester is used both for the pre-treatment and the cooking phase).
  • the digester is used both for the pre-treatment and the cooking phase.
  • a separate pre-treatment vessel as shown schematically in Figure 2
  • the digester could be in the form of a standard pre-impregnation vessel (used in 2-stage cooking), in which a counter-current washing zone at the bottom is incorporated.

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EP11188279.1A 2011-11-08 2011-11-08 Procédé de réduction en pâte kraft Withdrawn EP2592186A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP11188279.1A EP2592186A1 (fr) 2011-11-08 2011-11-08 Procédé de réduction en pâte kraft
PCT/EP2012/072120 WO2013068453A2 (fr) 2011-11-08 2012-11-08 Procédé de production de pâte kraft

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP11188279.1A EP2592186A1 (fr) 2011-11-08 2011-11-08 Procédé de réduction en pâte kraft

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EP2592186A1 true EP2592186A1 (fr) 2013-05-15

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EP11188279.1A Withdrawn EP2592186A1 (fr) 2011-11-08 2011-11-08 Procédé de réduction en pâte kraft

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EP (1) EP2592186A1 (fr)
WO (1) WO2013068453A2 (fr)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1633736A (en) * 1925-07-07 1927-06-28 Jr Frederick Knapp Fish Process of preparing paper pulp
US3520773A (en) 1968-05-17 1970-07-14 Mac Millan Bloedel Ltd Alkaline pulping processes with chemical pretreatment
US3560329A (en) 1968-12-27 1971-02-02 Combustion Eng Process for low sulfide chemical recovery
CA923255A (en) 1969-04-25 1973-03-27 Sivola Yrjo Method of making various sulphate cooking liquors
US3841962A (en) 1972-07-31 1974-10-15 Mac Millan Bloedel Ltd Hydrogen sulfide pretreatment of lignocellulosic materials in alkaline pulping processes
WO1997002383A1 (fr) * 1995-07-04 1997-01-23 Kvaerner Pulping Ab Procede relatif a la production de polysulfure par oxidation du sulfure contenu dans les liqueurs epuisees provenant de la cuisson de la cellulose au sulfate
EP0810321A1 (fr) * 1996-05-30 1997-12-03 Sunds Defibrator Pori Oy Procédé en discontinu pour préparation des pâtes kraft ameliorées
WO2000065150A1 (fr) * 1999-04-23 2000-11-02 The Babcock & Wilcox Company Procede de gazeification de liqueur residuaire a haute temperature et haute pression
WO2004092478A1 (fr) 2003-04-17 2004-10-28 Kvaerner Pulping Ab Impregnation de liquide acide dans des copeaux avant un procede de fabrication de pate au sulfate

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI45576C (fi) 1971-06-30 1972-07-10 Tampella Oy Ab Menetelmä väkevän rikkivedyn erottamiseksi sulfidipitoisesta liuoksest a

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1633736A (en) * 1925-07-07 1927-06-28 Jr Frederick Knapp Fish Process of preparing paper pulp
US3520773A (en) 1968-05-17 1970-07-14 Mac Millan Bloedel Ltd Alkaline pulping processes with chemical pretreatment
US3560329A (en) 1968-12-27 1971-02-02 Combustion Eng Process for low sulfide chemical recovery
CA923255A (en) 1969-04-25 1973-03-27 Sivola Yrjo Method of making various sulphate cooking liquors
US3841962A (en) 1972-07-31 1974-10-15 Mac Millan Bloedel Ltd Hydrogen sulfide pretreatment of lignocellulosic materials in alkaline pulping processes
WO1997002383A1 (fr) * 1995-07-04 1997-01-23 Kvaerner Pulping Ab Procede relatif a la production de polysulfure par oxidation du sulfure contenu dans les liqueurs epuisees provenant de la cuisson de la cellulose au sulfate
EP0810321A1 (fr) * 1996-05-30 1997-12-03 Sunds Defibrator Pori Oy Procédé en discontinu pour préparation des pâtes kraft ameliorées
WO2000065150A1 (fr) * 1999-04-23 2000-11-02 The Babcock & Wilcox Company Procede de gazeification de liqueur residuaire a haute temperature et haute pression
WO2004092478A1 (fr) 2003-04-17 2004-10-28 Kvaerner Pulping Ab Impregnation de liquide acide dans des copeaux avant un procede de fabrication de pate au sulfate

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
A.R. PROCTER, PULP AND PAPER CANADA, vol. 77, 12 November 1976 (1976-11-12)

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Publication number Publication date
WO2013068453A3 (fr) 2013-07-18
WO2013068453A2 (fr) 2013-05-16

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