CA2080026A1 - Novel method of bleaching of lignocelulosic pulp using persulphate - Google Patents
Novel method of bleaching of lignocelulosic pulp using persulphateInfo
- Publication number
- CA2080026A1 CA2080026A1 CA 2080026 CA2080026A CA2080026A1 CA 2080026 A1 CA2080026 A1 CA 2080026A1 CA 2080026 CA2080026 CA 2080026 CA 2080026 A CA2080026 A CA 2080026A CA 2080026 A1 CA2080026 A1 CA 2080026A1
- Authority
- CA
- Canada
- Prior art keywords
- pulp
- persulphate
- oven
- chlorine dioxide
- concentration
- 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.)
- Abandoned
Links
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
-
- 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
- D21C9/1026—Other features in bleaching processes
- D21C9/1036—Use of compounds accelerating or improving the efficiency of the processes
-
- 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
- D21C9/12—Bleaching ; Apparatus therefor with halogens or halogen-containing compounds
- D21C9/14—Bleaching ; Apparatus therefor with halogens or halogen-containing compounds with ClO2 or chlorites
-
- 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
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Paper (AREA)
Abstract
ABSTRACT
A process for the bleaching of lignocellulosic pulps using persulphate chemicals are admixed with conventional oxidizing agents selected from hydrogen peroxide and chlorine dioxide and combination thereof. A transition metal salt catalyst is added to effect improved pulp delignification with the combined pulp bleaching reagents of persulphate and chlorine dioxide.
A process for the bleaching of lignocellulosic pulps using persulphate chemicals are admixed with conventional oxidizing agents selected from hydrogen peroxide and chlorine dioxide and combination thereof. A transition metal salt catalyst is added to effect improved pulp delignification with the combined pulp bleaching reagents of persulphate and chlorine dioxide.
Description
fg 2 BAC~G~OUND OP TU~ INV~NTIOU
The pre~ent InYentlon rel~teD to e proce~ for th~b~e~chlng Or llgnocellulo-ic pulp8 u~ng persulph~te ch~lc~
The pre~ent InYentlon rel~teD to e proce~ for th~b~e~chlng Or llgnocellulo-ic pulp8 u~ng persulph~te ch~lc~
2. Pescr~Pt~on ot the PrlDr Art Withln lncreo~lng nv~ron~entcl dc~nd 80r cle~n-nnnufocture of poper~kln~ pulp,there i~ a need for l~pro~ed method Or ble~chlng pulp ~lth llttle or no u~e of chlorlne co~ fng compoundo.
Strong oY~tl~lng n8en~ auch o- monop-rox~oulphuric scld 01to are u~ed ln th- treot~ent of orgnnlc w~ste6, bl-~chlng o~ textll-~ ~nd ~ood pulp~, hoth odlu- ~nd pot~--lu- p-roulph~te lr com~erclull~
~olloble c ~tobl- eoll~ ~ater~l. Pcrsulph~te (820~) 18 ch-~lc~ diff~rent from poroYy~ono-ulphnte (RSOs-). The for~er 1~ dorl~e~ prlncipolly fro- the elcctroch-olcal tr--t--nt of ccldic ~ulphut-. The l-ttor lo t~plCollJ pro~uced ~rom the re~ctlon of ~lphur~c ~cld vlth hrdro~oD peroYide.
~Ss 1- u-cd ln the for. of coQ-orc~lly ~ blo ~iYed ~nlt of KHSOs,Y~S04 ~A~ ~2SO4~B~ ~ork-tod by DuPont Co.,Wll~lngotn,D~low~rc,~Ad-r tho t~oa- n~me o~ OXON~. Thl~
portleular ~xture i8 co~o~l~ known ~ oyer ~ B re-~ent (Bor. ,Vol. 34.P-8~ 853,1901~. ~enned~ aod Stock (J, Org.
Chc-.,Vol.25,p-ge 1901,1960) hn~e 8hown that the oxld~tion o org-nlc oubnt-nceo b~ th- lxtu~o of XHSOs,~HS04 ~nd SO~ ~roceed~ undcr ~n ~Itu cldic condltlono b~ th-pr-~ence o~ th- bloulphot- c-lt.
Xrln~-tnd et 1. (Nord. Pulp ~op. Reo. J.,Vol,3,No.2,1988) heve roport-d ~he u~- o~ ~odlu~ pcroulpbate for the orld-~lv~ ulphonotloA of kr-ft llgnln.
PORe 3 Huynh (II.S. Plltent 6,773,966) t~4che~ the UOQ of ~ xtur~
of por~ulphoto onlon and tron~ltlon ~etsl cotlon to offect thQ c~talytlc ox~d~tlon of modol l~gnln compound~ It ~s ~ener-llJ recognized thot tb- cho~lcal atruc~ure of ~odel llanin co~pouods are very ~lrreren~ ~ro~ LhAL o~ poly-dlsp-rsod llgnln ~ocromoleculee pre~ellL ln wood pulp ~nd eon-w~od pulp For exe~plo the o~ro~e ~ul~culu we~ t xceetc Z0 000 Dol~onc I~ lo e~on~oll~ ot solulle ln w~ter In contr~st the l~nln codel eo~pounds oo ua-d by unh are alread~ ooluble ln w~ter Tl~e ~olecul~r wel~h~ o~
the~e ll~nln model eo~puund~ 18 of tho order of 1-D8 th-n W0 They aro alr-od~ nln degredatlo~1 pro~uc~B. ~ee ror ex~aple Fengel and ~-gner Wood-Cheu~try IJltr~ctructure Reaetlon- pp 131-181 Do Gruyt-r N-~ York 1984 It 1~
unr-a-onable to oxtrcpolote thot the oxldotlvo dogrodoelon t-chnl~u- - dluclo--d b~ H~unh csn be applled to ths f~-ctlve runoval Or llgnln of ~ood and non-~oot pulp Roe~c1~ e~ al (Ger. O~en. ~R321a889) hnvu d1~clo~ed th~
l~ultaneouo derl~ln~ and bloochlng Or eexLlle ~atorlol ~ro- textlle lbroo b~ u-ln~ pereulphoto oo a perox~de ctlYator .
Zaklu ~t nl (~hlm. Drev (Rl~o) ~ol.9 pp 109-117 1971) h-v- tudl-d th- dellgnlflcntlon ectlon of am~onlum p-ruulph-t- on prue- wood C-ol (U.8. Pat-nt 4 404 061) teaehes ths uoe of ~onoper~ulphurlc acld and lt~ sal~s ror the ~leochlng o~
ll~noc-lluloslc ~eterlels ln p-rtlculor wood chlpa or~
dollgnl~l-d Ylth o ~lxtur- of persulphdte ~ultJ und-r olkollno krett-type cook~n~ condltlona Syrln~-r ot l tU S P~tent 4"S6,aO0) t-~choo the use 0 euprle lon~ to produc- ~olt~ of onoperoxg~ulphurlc ~cld ~hleh In turn 1- u-cd for th- bl-~chlng of pulp Tho e~foctlvene-- o~ thl- prlor ast lo l~itod to dollgntrled pulp 1.- lo~-llgnln pulp ~hich b~s alr-ody boen prevlou-ly chlorlnutQd nd ~lknll-oxtracted Unfortun-tel~ the-e proc-asco re ll~lted to usos wlch d-llgnltlod pulp~ or tO uoe ~lth ~ood chlpc prlor to con~-ntlonel puljln~ procod~re.
Mor-o~ar the rel-tlvel~ hlgh cost~ of per~ulphAte~ c ~oll ~o -~t- o~ nonop-rox~oulphuolc cld h~vo llmlted tho ~lde-pr-od co~mercl-l ppllca~on o~ thi~ opprooc~. ~nd ln o-n~ co-es tho pulp ean onl~ be bleochet to ccop~nble brlgbtno60 l-vela ~l~l) con~ldo~abl~ c~ncomml~ant loa~ Or ph~oleal ot~on~th-P-~o 4 There 19 a need ~or l~provln~ ~he oxi~stlve ble~chin~
t-chnology to prov~do f~-ctlve and ~cono~lcal ~auuf~ctu~
o~ pulp tor paper~akln8 SUMMA~S OP rN~N~ION
~ proce~- h~c bo-n dl~cov-red ~or the ef fectlve dell~nlflc~tion of ~ood a~d non-~ood pulp,~hlch comprlsec the tepc of ~ddln8 an alk~ otal pcraulphota cnd an ~xltlz~n~
go~C,cnd rosctln~ thc a~d raQ8cnto wlth ~ny llgnocellulos1c wood or non-wood pulp,und~r condltlo~ vf ~dcratc t-~peraturoa and tl~ea ~ h-n the preaent laventlon 1- pr-c~lcad,llgnin-eont~lnln8 pulp 1 t d~ 8nlL~lad tO reduce the u~tg~ of aubaequent eho~lc~l re-~ent- for blesching or brlghtenin~ of the pulp. Tho ~p-nc llqùor contalnlng rerldu~l chemlcale ro~
th- pr---nt Inv-ntlon ~ay bc r-cyclod to l~provu thc ncono~y of pulp tr~atoent of tho preecnt lnv-ntlon ~nother ~d~nte~e ~tt-ndant to the prca-nt lnv-ntlon 1- tho sl~nl~cant pulp bl-achlng or brlght-nlng ~ect achl-vod wlthout th~ uae o~
any chlorlne co~t~l~lng chc~lc-la. ~n p~rrlcular,~ultl--t-~o non~ c-ntal chlorlne blenchln~ o~ pulp can be e~Eected efflclently ~Ith the lncluulon of persulphate tre~t~ent atep,to ach~eve -tl~f-ctor~ brlght~l-ao ldvel~ T~ non-per~ulphate bl--chlng at-gnJ of the nulti-ctag- bleachln~
chc~e of thr preaent ln~-~t~on ~aJ bo conv-ntlonal ln na~ure DBTAlLLD DESCRIP~rOR OF T0~ IN~TION
P-r-ulph-t- le known c~ndldat- oYld-tlv- blc-chlng ~-nt for pulp. T~ d~te~lee r-lot~vclr hl~h co~t he~ preclude~
nJ co---rcl-l loe-r--t ~lthlo th- pulp bl--ching. Ue h~e now t~-co~ered th-t ~h~n poroulpbote 1~ u6~d ln colubln~tlon wlth ~ueh bl--chlng gon~ ~ hydrogen pero~lde ~nd chlorlne dlo~ld-,lt c-n nhnnc- tho dellgnlf~lng urr~ct o~ t~eoo bl--chln~ ch-~lc~
~ he lk~ ot-l p-roulph~te uSot In the proeent In~-ntlon lo ~v~lloble conD-rclally~ Elth~ ~odluD, pot-~luo or a~monlu~ ~-lt o~r bo u~ed ln Lhe chemlcol ch~rge ran~- sf 0.5% to 5.0% bo~od on ovon-dr~ ~e~ght Or pulp. The orldlrl~g a8ent u-ed vlth p-r-ulphat- as set forth ln tho ~r-eent lnventlon ma~ be aelect~d ~rom,~mon~ othars,hydrog-n pcrorld- nd chlorln- dlo~ld-,-nd cooblnatlon~ thoroof. Th-ehe-lc~ chorg- of o~ldlrlng ogent to b- used wlth per~ulphnto ln ln th- r-n8e of 0 lS to l0%,bo-od on ovon-dry welght of pulp.
~8e 5 Whe~ chlorlne dloxlde le ~elecLed aB the oxldizln~
~ent to be uJ~d ~l~h ~er~ul~hoto,n tron~ltlon ~et~l c-tal~9t, ln the ran8e o~ 10 to 200 m~lllgro-~ p~r kllogram o~ oven-dry pulp,l~ to be added to f~-ct ~ls~aetory dellgnlflc~tlon of the pulp The tr~ tlon ~et~l eat-l~et ~y be ~alt~ ~f lron, copper or ang~neoe,~nd co~bloetloD~ theraof Pulp ~hlch ha~ been tre~ted ~ith combln~tlon of per~ulph~t- ~nd ~el-ctod o~izldlng ag~n~ ~n ~lxturo mor be bl-~ch~d eubaequently ln ono or moro conv~ntion~l bl~achin~
ategea to of~ect ~lgh pulp brl~heneo~
In or~or to dl~clo~e mo~e cle-~lr th~ n-uur~ oE the pre~ent in~entlon,tha rollowlne l~bor~torr ~ulp tr~at~nt x--pl-~ llluetr~tln~ thc lnv-nt~on are glYen Tho ~peclflc con-ontlon~l ble~chlng technlguoo unod herewlthln ar~ vell kno~n to thoJe ~)tLlled ln tho ~rt.
Pulp Unbl~-chod mi~-d C-n~dl~n northern oft~ood ~ra~t pulp;
~appA nu-ber 29 3 ~leco~lty 40.~ ~Pa.s: brlghtne--28 22 Photo~olt Tr-~t-ont condltlon~ T¢~porature 60 de8 C; con-l~tonc~ 10 ~;
t$~e 90 olnuto-T--t Run ___________________________ ov-n-drr pulp~8 5 S 5 5 N~ S20a,~ OD pulp 0 1 0 ,~ OD pulp 1 1 2 2 ~-0~,~ OD pulp 1 2 1 2 1 2 1 2 ~C2S103,S OD pulp 4 4 4 4 M~04 7N~O,~ OD pulp 0 15 Q 15 0 15 0 1 End pH Or ~re~tnent 12 0 11 8 11 9 12 ~epp~ nu-ber 2~ 3 29 7 23 8 22 3 ~l-co-ltr,-P~ - ~0 4 28 4 2~ 8 24 5 8r~htn-~a,% PV 32 6 33 6 33.9 33 1 Se-t Run~ M283 nd M29~ cle-rl~ ~ow~ tbe beneflt o~ che ddltlo~ o~ ood u- per-ulpb-~e to enhence thc ocLlvl~ of hydrogcn poroxl~c o~ the tecreaae ln ~ppo nu~ber The puly vloco-ltr lo ~tll~ ~-lnt~ln-t vlthln accept6bl~ r-n8e ~lth the tr-~t~ent procedurc o~ the pre-ent lnventlon Pulp: Unbleached mixed Canadian northern softwood kraft pulp;
Kappa number 30.0; viscosity 39.0 mPa.s; brightness 27.0% Photovolt Lab treatment conditions: Temperature 50 deg.C; consistency 10.0%; time 30 minutes Test Run oven-dry pulp g. 10 10 10 Na2S2Og % OD pulp O
ClO~ % OD pulp 1.60 1.60 1.60 Fe+3 mg/kg OD pulp O 0 14 End pH of treatment 2.16 2.10 2.10 Kappa number 19.5 20.0 17.7 Viscosity mPa.s 36.2 33.6 29.5 Brightness % PV 33.5 33.8 33.3 Test Run M413 illustrates that sodium persulphate may be used beneficially with chlorine dioxide in presence of iron catal~st. As given in Test Run M386 absence of iron catlyst provides neglible beneficial effect of persulphate-chlorine dioxide treatement of pulp. Significant improvement in Kappa number reduction is achieved with the present invention.
208002~
Pulp: Unbleached mixed Canadian northern softwood kraft pulp;
~appa number 30.0; vi9c08ity 39.0 mPa.s; brightness 27.0% Photo~olt Lab treatment conditions: Temperature 50 deg.C; consistency 10.0%; time 30 minutes Test Run ____________________________ oYen-dry pulp,g. 10 10 10 10 Na2S20g,% OD pulp 2 2 2 2 C102,% OD pulp 1.83 1.83 1 83 1 83 Fe~J,mg/kg OD pulp44 87 1i4 500 End pH of treatment 2.01 1.92 1.91 1.90 Kappa number 16.7 16.2 15.9 16.7 Viscosit~,mPa.s 30.2 30.6 32 7 34 4 Brightness,% PV 35.2 34.9 35 7 28 5 These tests have une~pectedly shown that there is an optimum range of catal~st addition in the combined persulphate-chlorine dio~ide treatment of pulp,to achie~e low Kappa number,high ~iscosit~ and high brightness of the treated pulp.
2~800~
Pulp: Unbleached mixed Canadian northern softwood kraft pulp;
Rappa number 30.0; Viscosity 38.0 mPa.s; Brightness 30.0% Photovolt Lab treatment conditions: Consistency 10.0%; Time 90 minutes reatment sequence: D277/86 followed by D293,then by D299 and finally by D301 Test Run _______________________________ oven-dry pulp,g. 40 30 10 8 Na2S20g,% OD pulp 0 3 0 0 H2O2,% OD pulp 1 0 10 10 NaOH,% on OD pulp 1.2 0 3.5 3.5 H3P04,% on OD pulp 0 3 0 0 Na2SiO3,% OD pulp 4 0 0 0 MgSO4.7H2O,% on OD pulp 0.15 0 0 0 DTMPA,% on OD pulp O 0 0.5 0.3 Temperature,deg.C 60 50 75 75 End pH of treatement 11.8 1.9 10.8 10.9 ~appa number 24.7 24.6 17.7 13.0 Vigcosity,mPa.s 33.7 30.0 24.1 22.3 Brightnes~,% PV 38.2 39.9 60.3 68.8 _____________________________________________________________ DTMP~ - sodium salt of diethylenetriamine pentamethylene phosphonic acid,chelatant Test Runs D277/86,D293,D299 and D301 show the continued benefit of sodium persulphate treatment stage in a 4-stage bleachlng sequence to achieve bleached pulp with a brightness of 68.8%. The resitual hytrogen peroxide was 73% (of input) in Stage 3 and 76% (of the input) in Stage 4. The residual bleaching liquor may be recycled for reuse.
Pulp: Vnbleached mixed European softwood kraft pulp; Rappa number 35.3; viscosity 39.0 mPa.s; brightness 25.9%
Photovolt Lab treatment conditions: Consistency 10.0%;
Treatment sequence: M687,followed by M688.
Test Run oven-dry pulp,g. 44.3 8.0 Na2S20g,% OD pulp 0.5 0 H202,% OD pulp 5.0 10.0 NaOH,% on OD pulp 1.7 3.4 Na2SiO3,% OD pulp 4 0 MgS04.7H20,% on OD pulp0.15 0 DTMPA,% on OD pulp 0 0.5 Temperature,deg.C 60 75 Time,minutes 120 150 ~nd pH of treatment 10.6 10.6 Kappa number 26.7 16.5 Viscosity,mPa.s 24.1 18.0 Brightness,% PV 44.9 59.0 _____________________________________________________________ DTMPA sodium salt of diethylenetriamine pentamethylene phosphonic acid,cbelatant Te8t Runs M387 and M38B show the inclusion of a combined sodium persulphate-h~drogen peroxide treatment sta8e in a 2-stage bleaching sequence to achieve bleached pulp with a brlghtness of 59.0%. The residual hydrogen peroxide was 77%
(of the input) in Stage I and 89% (of the input) in Stage 2.
The resldual bleaching liquor may be recycled for reuse.
Strong oY~tl~lng n8en~ auch o- monop-rox~oulphuric scld 01to are u~ed ln th- treot~ent of orgnnlc w~ste6, bl-~chlng o~ textll-~ ~nd ~ood pulp~, hoth odlu- ~nd pot~--lu- p-roulph~te lr com~erclull~
~olloble c ~tobl- eoll~ ~ater~l. Pcrsulph~te (820~) 18 ch-~lc~ diff~rent from poroYy~ono-ulphnte (RSOs-). The for~er 1~ dorl~e~ prlncipolly fro- the elcctroch-olcal tr--t--nt of ccldic ~ulphut-. The l-ttor lo t~plCollJ pro~uced ~rom the re~ctlon of ~lphur~c ~cld vlth hrdro~oD peroYide.
~Ss 1- u-cd ln the for. of coQ-orc~lly ~ blo ~iYed ~nlt of KHSOs,Y~S04 ~A~ ~2SO4~B~ ~ork-tod by DuPont Co.,Wll~lngotn,D~low~rc,~Ad-r tho t~oa- n~me o~ OXON~. Thl~
portleular ~xture i8 co~o~l~ known ~ oyer ~ B re-~ent (Bor. ,Vol. 34.P-8~ 853,1901~. ~enned~ aod Stock (J, Org.
Chc-.,Vol.25,p-ge 1901,1960) hn~e 8hown that the oxld~tion o org-nlc oubnt-nceo b~ th- lxtu~o of XHSOs,~HS04 ~nd SO~ ~roceed~ undcr ~n ~Itu cldic condltlono b~ th-pr-~ence o~ th- bloulphot- c-lt.
Xrln~-tnd et 1. (Nord. Pulp ~op. Reo. J.,Vol,3,No.2,1988) heve roport-d ~he u~- o~ ~odlu~ pcroulpbate for the orld-~lv~ ulphonotloA of kr-ft llgnln.
PORe 3 Huynh (II.S. Plltent 6,773,966) t~4che~ the UOQ of ~ xtur~
of por~ulphoto onlon and tron~ltlon ~etsl cotlon to offect thQ c~talytlc ox~d~tlon of modol l~gnln compound~ It ~s ~ener-llJ recognized thot tb- cho~lcal atruc~ure of ~odel llanin co~pouods are very ~lrreren~ ~ro~ LhAL o~ poly-dlsp-rsod llgnln ~ocromoleculee pre~ellL ln wood pulp ~nd eon-w~od pulp For exe~plo the o~ro~e ~ul~culu we~ t xceetc Z0 000 Dol~onc I~ lo e~on~oll~ ot solulle ln w~ter In contr~st the l~nln codel eo~pounds oo ua-d by unh are alread~ ooluble ln w~ter Tl~e ~olecul~r wel~h~ o~
the~e ll~nln model eo~puund~ 18 of tho order of 1-D8 th-n W0 They aro alr-od~ nln degredatlo~1 pro~uc~B. ~ee ror ex~aple Fengel and ~-gner Wood-Cheu~try IJltr~ctructure Reaetlon- pp 131-181 Do Gruyt-r N-~ York 1984 It 1~
unr-a-onable to oxtrcpolote thot the oxldotlvo dogrodoelon t-chnl~u- - dluclo--d b~ H~unh csn be applled to ths f~-ctlve runoval Or llgnln of ~ood and non-~oot pulp Roe~c1~ e~ al (Ger. O~en. ~R321a889) hnvu d1~clo~ed th~
l~ultaneouo derl~ln~ and bloochlng Or eexLlle ~atorlol ~ro- textlle lbroo b~ u-ln~ pereulphoto oo a perox~de ctlYator .
Zaklu ~t nl (~hlm. Drev (Rl~o) ~ol.9 pp 109-117 1971) h-v- tudl-d th- dellgnlflcntlon ectlon of am~onlum p-ruulph-t- on prue- wood C-ol (U.8. Pat-nt 4 404 061) teaehes ths uoe of ~onoper~ulphurlc acld and lt~ sal~s ror the ~leochlng o~
ll~noc-lluloslc ~eterlels ln p-rtlculor wood chlpa or~
dollgnl~l-d Ylth o ~lxtur- of persulphdte ~ultJ und-r olkollno krett-type cook~n~ condltlona Syrln~-r ot l tU S P~tent 4"S6,aO0) t-~choo the use 0 euprle lon~ to produc- ~olt~ of onoperoxg~ulphurlc ~cld ~hleh In turn 1- u-cd for th- bl-~chlng of pulp Tho e~foctlvene-- o~ thl- prlor ast lo l~itod to dollgntrled pulp 1.- lo~-llgnln pulp ~hich b~s alr-ody boen prevlou-ly chlorlnutQd nd ~lknll-oxtracted Unfortun-tel~ the-e proc-asco re ll~lted to usos wlch d-llgnltlod pulp~ or tO uoe ~lth ~ood chlpc prlor to con~-ntlonel puljln~ procod~re.
Mor-o~ar the rel-tlvel~ hlgh cost~ of per~ulphAte~ c ~oll ~o -~t- o~ nonop-rox~oulphuolc cld h~vo llmlted tho ~lde-pr-od co~mercl-l ppllca~on o~ thi~ opprooc~. ~nd ln o-n~ co-es tho pulp ean onl~ be bleochet to ccop~nble brlgbtno60 l-vela ~l~l) con~ldo~abl~ c~ncomml~ant loa~ Or ph~oleal ot~on~th-P-~o 4 There 19 a need ~or l~provln~ ~he oxi~stlve ble~chin~
t-chnology to prov~do f~-ctlve and ~cono~lcal ~auuf~ctu~
o~ pulp tor paper~akln8 SUMMA~S OP rN~N~ION
~ proce~- h~c bo-n dl~cov-red ~or the ef fectlve dell~nlflc~tion of ~ood a~d non-~ood pulp,~hlch comprlsec the tepc of ~ddln8 an alk~ otal pcraulphota cnd an ~xltlz~n~
go~C,cnd rosctln~ thc a~d raQ8cnto wlth ~ny llgnocellulos1c wood or non-wood pulp,und~r condltlo~ vf ~dcratc t-~peraturoa and tl~ea ~ h-n the preaent laventlon 1- pr-c~lcad,llgnin-eont~lnln8 pulp 1 t d~ 8nlL~lad tO reduce the u~tg~ of aubaequent eho~lc~l re-~ent- for blesching or brlghtenin~ of the pulp. Tho ~p-nc llqùor contalnlng rerldu~l chemlcale ro~
th- pr---nt Inv-ntlon ~ay bc r-cyclod to l~provu thc ncono~y of pulp tr~atoent of tho preecnt lnv-ntlon ~nother ~d~nte~e ~tt-ndant to the prca-nt lnv-ntlon 1- tho sl~nl~cant pulp bl-achlng or brlght-nlng ~ect achl-vod wlthout th~ uae o~
any chlorlne co~t~l~lng chc~lc-la. ~n p~rrlcular,~ultl--t-~o non~ c-ntal chlorlne blenchln~ o~ pulp can be e~Eected efflclently ~Ith the lncluulon of persulphate tre~t~ent atep,to ach~eve -tl~f-ctor~ brlght~l-ao ldvel~ T~ non-per~ulphate bl--chlng at-gnJ of the nulti-ctag- bleachln~
chc~e of thr preaent ln~-~t~on ~aJ bo conv-ntlonal ln na~ure DBTAlLLD DESCRIP~rOR OF T0~ IN~TION
P-r-ulph-t- le known c~ndldat- oYld-tlv- blc-chlng ~-nt for pulp. T~ d~te~lee r-lot~vclr hl~h co~t he~ preclude~
nJ co---rcl-l loe-r--t ~lthlo th- pulp bl--ching. Ue h~e now t~-co~ered th-t ~h~n poroulpbote 1~ u6~d ln colubln~tlon wlth ~ueh bl--chlng gon~ ~ hydrogen pero~lde ~nd chlorlne dlo~ld-,lt c-n nhnnc- tho dellgnlf~lng urr~ct o~ t~eoo bl--chln~ ch-~lc~
~ he lk~ ot-l p-roulph~te uSot In the proeent In~-ntlon lo ~v~lloble conD-rclally~ Elth~ ~odluD, pot-~luo or a~monlu~ ~-lt o~r bo u~ed ln Lhe chemlcol ch~rge ran~- sf 0.5% to 5.0% bo~od on ovon-dr~ ~e~ght Or pulp. The orldlrl~g a8ent u-ed vlth p-r-ulphat- as set forth ln tho ~r-eent lnventlon ma~ be aelect~d ~rom,~mon~ othars,hydrog-n pcrorld- nd chlorln- dlo~ld-,-nd cooblnatlon~ thoroof. Th-ehe-lc~ chorg- of o~ldlrlng ogent to b- used wlth per~ulphnto ln ln th- r-n8e of 0 lS to l0%,bo-od on ovon-dry welght of pulp.
~8e 5 Whe~ chlorlne dloxlde le ~elecLed aB the oxldizln~
~ent to be uJ~d ~l~h ~er~ul~hoto,n tron~ltlon ~et~l c-tal~9t, ln the ran8e o~ 10 to 200 m~lllgro-~ p~r kllogram o~ oven-dry pulp,l~ to be added to f~-ct ~ls~aetory dellgnlflc~tlon of the pulp The tr~ tlon ~et~l eat-l~et ~y be ~alt~ ~f lron, copper or ang~neoe,~nd co~bloetloD~ theraof Pulp ~hlch ha~ been tre~ted ~ith combln~tlon of per~ulph~t- ~nd ~el-ctod o~izldlng ag~n~ ~n ~lxturo mor be bl-~ch~d eubaequently ln ono or moro conv~ntion~l bl~achin~
ategea to of~ect ~lgh pulp brl~heneo~
In or~or to dl~clo~e mo~e cle-~lr th~ n-uur~ oE the pre~ent in~entlon,tha rollowlne l~bor~torr ~ulp tr~at~nt x--pl-~ llluetr~tln~ thc lnv-nt~on are glYen Tho ~peclflc con-ontlon~l ble~chlng technlguoo unod herewlthln ar~ vell kno~n to thoJe ~)tLlled ln tho ~rt.
Pulp Unbl~-chod mi~-d C-n~dl~n northern oft~ood ~ra~t pulp;
~appA nu-ber 29 3 ~leco~lty 40.~ ~Pa.s: brlghtne--28 22 Photo~olt Tr-~t-ont condltlon~ T¢~porature 60 de8 C; con-l~tonc~ 10 ~;
t$~e 90 olnuto-T--t Run ___________________________ ov-n-drr pulp~8 5 S 5 5 N~ S20a,~ OD pulp 0 1 0 ,~ OD pulp 1 1 2 2 ~-0~,~ OD pulp 1 2 1 2 1 2 1 2 ~C2S103,S OD pulp 4 4 4 4 M~04 7N~O,~ OD pulp 0 15 Q 15 0 15 0 1 End pH Or ~re~tnent 12 0 11 8 11 9 12 ~epp~ nu-ber 2~ 3 29 7 23 8 22 3 ~l-co-ltr,-P~ - ~0 4 28 4 2~ 8 24 5 8r~htn-~a,% PV 32 6 33 6 33.9 33 1 Se-t Run~ M283 nd M29~ cle-rl~ ~ow~ tbe beneflt o~ che ddltlo~ o~ ood u- per-ulpb-~e to enhence thc ocLlvl~ of hydrogcn poroxl~c o~ the tecreaae ln ~ppo nu~ber The puly vloco-ltr lo ~tll~ ~-lnt~ln-t vlthln accept6bl~ r-n8e ~lth the tr-~t~ent procedurc o~ the pre-ent lnventlon Pulp: Unbleached mixed Canadian northern softwood kraft pulp;
Kappa number 30.0; viscosity 39.0 mPa.s; brightness 27.0% Photovolt Lab treatment conditions: Temperature 50 deg.C; consistency 10.0%; time 30 minutes Test Run oven-dry pulp g. 10 10 10 Na2S2Og % OD pulp O
ClO~ % OD pulp 1.60 1.60 1.60 Fe+3 mg/kg OD pulp O 0 14 End pH of treatment 2.16 2.10 2.10 Kappa number 19.5 20.0 17.7 Viscosity mPa.s 36.2 33.6 29.5 Brightness % PV 33.5 33.8 33.3 Test Run M413 illustrates that sodium persulphate may be used beneficially with chlorine dioxide in presence of iron catal~st. As given in Test Run M386 absence of iron catlyst provides neglible beneficial effect of persulphate-chlorine dioxide treatement of pulp. Significant improvement in Kappa number reduction is achieved with the present invention.
208002~
Pulp: Unbleached mixed Canadian northern softwood kraft pulp;
~appa number 30.0; vi9c08ity 39.0 mPa.s; brightness 27.0% Photo~olt Lab treatment conditions: Temperature 50 deg.C; consistency 10.0%; time 30 minutes Test Run ____________________________ oYen-dry pulp,g. 10 10 10 10 Na2S20g,% OD pulp 2 2 2 2 C102,% OD pulp 1.83 1.83 1 83 1 83 Fe~J,mg/kg OD pulp44 87 1i4 500 End pH of treatment 2.01 1.92 1.91 1.90 Kappa number 16.7 16.2 15.9 16.7 Viscosit~,mPa.s 30.2 30.6 32 7 34 4 Brightness,% PV 35.2 34.9 35 7 28 5 These tests have une~pectedly shown that there is an optimum range of catal~st addition in the combined persulphate-chlorine dio~ide treatment of pulp,to achie~e low Kappa number,high ~iscosit~ and high brightness of the treated pulp.
2~800~
Pulp: Unbleached mixed Canadian northern softwood kraft pulp;
Rappa number 30.0; Viscosity 38.0 mPa.s; Brightness 30.0% Photovolt Lab treatment conditions: Consistency 10.0%; Time 90 minutes reatment sequence: D277/86 followed by D293,then by D299 and finally by D301 Test Run _______________________________ oven-dry pulp,g. 40 30 10 8 Na2S20g,% OD pulp 0 3 0 0 H2O2,% OD pulp 1 0 10 10 NaOH,% on OD pulp 1.2 0 3.5 3.5 H3P04,% on OD pulp 0 3 0 0 Na2SiO3,% OD pulp 4 0 0 0 MgSO4.7H2O,% on OD pulp 0.15 0 0 0 DTMPA,% on OD pulp O 0 0.5 0.3 Temperature,deg.C 60 50 75 75 End pH of treatement 11.8 1.9 10.8 10.9 ~appa number 24.7 24.6 17.7 13.0 Vigcosity,mPa.s 33.7 30.0 24.1 22.3 Brightnes~,% PV 38.2 39.9 60.3 68.8 _____________________________________________________________ DTMP~ - sodium salt of diethylenetriamine pentamethylene phosphonic acid,chelatant Test Runs D277/86,D293,D299 and D301 show the continued benefit of sodium persulphate treatment stage in a 4-stage bleachlng sequence to achieve bleached pulp with a brightness of 68.8%. The resitual hytrogen peroxide was 73% (of input) in Stage 3 and 76% (of the input) in Stage 4. The residual bleaching liquor may be recycled for reuse.
Pulp: Vnbleached mixed European softwood kraft pulp; Rappa number 35.3; viscosity 39.0 mPa.s; brightness 25.9%
Photovolt Lab treatment conditions: Consistency 10.0%;
Treatment sequence: M687,followed by M688.
Test Run oven-dry pulp,g. 44.3 8.0 Na2S20g,% OD pulp 0.5 0 H202,% OD pulp 5.0 10.0 NaOH,% on OD pulp 1.7 3.4 Na2SiO3,% OD pulp 4 0 MgS04.7H20,% on OD pulp0.15 0 DTMPA,% on OD pulp 0 0.5 Temperature,deg.C 60 75 Time,minutes 120 150 ~nd pH of treatment 10.6 10.6 Kappa number 26.7 16.5 Viscosity,mPa.s 24.1 18.0 Brightness,% PV 44.9 59.0 _____________________________________________________________ DTMPA sodium salt of diethylenetriamine pentamethylene phosphonic acid,cbelatant Te8t Runs M387 and M38B show the inclusion of a combined sodium persulphate-h~drogen peroxide treatment sta8e in a 2-stage bleaching sequence to achieve bleached pulp with a brlghtness of 59.0%. The residual hydrogen peroxide was 77%
(of the input) in Stage I and 89% (of the input) in Stage 2.
The resldual bleaching liquor may be recycled for reuse.
Claims (12)
1. A process in which delignification of any cellulosic pulp is by the use of alkali metal persulphate with one or more oxidizing agents.
2. The process of claim 1 wherein the alkali metal persulphate may be selected from sodium,potassium or ammonium,and combination thereof.
3. The method of claim 2 wherein the concentration of said persulphate is 0.5% to 5.0% based on oven-dry weight of pulp.
4. The process of claim 1 wherein the oxidizing agent is hydrogen peroxide,as used commonly in the alkaline regime.
5. The method of claim 4 wherein the concentration of hydrogen peroxide is 0.1% to 10% based on oven-dry weight of pulp.
6. The process of claim 1 wherein the oxidizing agent is chlorine dioxide,as used commonly in the acidic regime.
7. The method of claim 6 wherein the concentration of chlorine dioxide is 0.1% to 10% based on oven-dry weight of pulp.
8. The process of claim 1 wherein the alkali persulphate is used admix with chlorine dioxide in the presence of a transition metal catalyst.
9. The method of claim 8 wherein the metal catalyst may be selected from iron,copper and manganese,and mixture thereof.
10. The method of claim 8 wherein the ionic concentration of transition metal catalyst ion is between 10 milligrams per kilogram of oven-dry pulp to 200 milligrams per kilogram of oven-dry pulp.
11. The process of claim 1 wherein the residual treatment liquor extracted from is pulp is recycled for reuse.
12. The process of claim 1 wherein subsequent one or more stages of known bleaching methods are used to achieve high pulp brightness.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2080026 CA2080026A1 (en) | 1992-09-09 | 1992-09-09 | Novel method of bleaching of lignocelulosic pulp using persulphate |
| AU58920/94A AU5892094A (en) | 1992-09-09 | 1993-09-09 | Novel method of bleaching of lignocellulosic pulp using persulphate |
| PCT/CA1993/000362 WO1994005851A1 (en) | 1992-09-09 | 1993-09-09 | Novel method of bleaching of lignocellulosic pulp using persulphate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2080026 CA2080026A1 (en) | 1992-09-09 | 1992-09-09 | Novel method of bleaching of lignocelulosic pulp using persulphate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2080026A1 true CA2080026A1 (en) | 1994-03-10 |
Family
ID=4150504
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2080026 Abandoned CA2080026A1 (en) | 1992-09-09 | 1992-09-09 | Novel method of bleaching of lignocelulosic pulp using persulphate |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU5892094A (en) |
| CA (1) | CA2080026A1 (en) |
| WO (1) | WO1994005851A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3698178B2 (en) * | 1995-09-22 | 2005-09-21 | 三菱瓦斯化学株式会社 | Process for bleaching chemical pulp for papermaking |
| US6511578B2 (en) | 1997-03-21 | 2003-01-28 | Peroxid-Chemie Gmbh & Co. Kg | Bleaching and delignifying cellulosic pulp using caroate/caro's acid solution |
| WO1998042911A1 (en) * | 1997-03-21 | 1998-10-01 | Peroxid-Chemie Gmbh & Co. Kg | Bleaching and delignifying cellulose using caroate/caro's acid and production of same |
| CA2956661C (en) | 2014-07-28 | 2018-08-28 | Anomera Inc. | Method for producing functionalized nanocrystalline cellulose and functionalized nanocrystalline cellulose thereby produced |
| AR104939A1 (en) | 2015-06-10 | 2017-08-23 | Chemsenti Ltd | OXIDATIVE METHOD TO GENERATE CHLORINE DIOXIDE |
| AR104940A1 (en) * | 2015-06-10 | 2017-08-23 | Chemsenti Ltd | METHOD FOR GENERATING CHLORINE DIOXIDE |
| JP7100315B2 (en) * | 2018-05-30 | 2022-07-13 | 三菱瓦斯化学株式会社 | How to make bleached pulp |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU670650A1 (en) * | 1978-01-09 | 1979-06-30 | Пермский политехнический институт | Method of obtaining semi-finished finrous product |
| US4773966A (en) * | 1986-09-29 | 1988-09-27 | Regents Of The University Of Minnesota | Oxidative degradation of lignin with inorganic metal complexes |
| FR2626020B1 (en) * | 1988-01-20 | 1990-05-04 | Protex Manuf Prod Chimiq | IMPROVED PROCESS FOR BLEACHING CELLULOSIC FIBERS USING HYDROGEN PEROXIDE IN AN ALKALINE MEDIUM |
-
1992
- 1992-09-09 CA CA 2080026 patent/CA2080026A1/en not_active Abandoned
-
1993
- 1993-09-09 WO PCT/CA1993/000362 patent/WO1994005851A1/en active Application Filing
- 1993-09-09 AU AU58920/94A patent/AU5892094A/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| WO1994005851A1 (en) | 1994-03-17 |
| AU5892094A (en) | 1994-03-29 |
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