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Title:
PROCESS OF PRODUCING FIBRILLATED NANOCELLULOSE WITH LOW ENERGY CONSUMPTION
Document Type and Number:
WIPO Patent Application WO/2018/094493
Kind Code:
A1
Abstract:
The present invention refers to the separation of cellulose pulp into distinct fractions with different draining and morphological characteristics, as well as the use of part of these fractions for the production of nanocellulose. The process in reference combines the unitary operations of fiber separation, thickening to a certain consistency, draining and drying of the cellulosic pulp with the high drainage ability and production of nanocellulose from high primary fines content pulp. The process may consider any cellulosic pulp fiber derived from short or long fiber woods such as Eucalyptus, Corymbia, Birch, Aspen, Pinus, recycled fibers, etc., their residues such as bark, sawdust, etc.

Inventors:
RAMIRES HELOISA OGUSHI ROMEIRO (BR)
DEMUNER BRAZ JOSÉ (BR)
Application Number:
PCT/BR2017/050355
Publication Date:
May 31, 2018
Filing Date:
November 23, 2017
Export Citation:
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Assignee:
FIBRIA CELULOSE SA (BR)
International Classes:
D21C3/26; D21C7/00; D21H11/02
Domestic Patent References:
WO2013188657A12013-12-19
WO2015171714A12015-11-12
Foreign References:
US7005034B12006-02-28
US5879510A1999-03-09
Attorney, Agent or Firm:
SOUZA, Marcelo Oliveira De et al. (BR)
Download PDF:
Claims:
CLAI IV5

1. Process of produci ng fi bri M ated nanocel I ul ose with I ow energy consurrpti on characteri zed by conpri si ng the steps of:

a) cooki ng and bl eachi ng of bi orrass, generati ng a rrass ri ch i n eel I ul os i c and herri eel I ul osi c polymer chai ns, conpri si ng very reduced amount of I i gni n and extractives.

b) sel ecti ng and di recti ng a eel I ul osi c materi al froma fi ber l i ne havi ng the fol l owi ng characteri sti cs: b.1) average fi ber l ength: 0.3 to 2.5 mrn and b.2) pri mary fi ne content: 3% to 30% of fi nes by mass;

c) fracti onati ng the sel ected materi al by means of a f r act i onat i ng syst em

d) separati ng one strearn with the hi gh- pr i rrary fi nes content materi al fracti on obtai ned i n step c), i n a percentage range from 10% to 90% of pri mary fi nes and consi stenci es of 0, 02% to 1%

e) thi ckeni ng of thi s stream unti l consistenci es of 2% to 15%

f) subnitti ng the thi ckened materi al to a nanof i br i I I at ed cel l ul ose producti on process, wherei n it i s subj ected to mechani cal refi ni ng energy, bei ng the energy consurrpti on used for the generati on of the nanof i br i I I ar cel l ul ose smal l er than i n compari son with common eel I ul osi c pul p st ar t i ng mat er i al .

g) separati ng the other fracti on stream with l ower pr i rrary f i nes cont ent , so cal I ed hi gh dr ai nage pul p, pr esent i ng a rrassi c amount of fi nes of about 3 to 8% with signifi cant l ower resi stance to drai nabi l ity and water retenti on val ue, presenti ng a °SR reducti on of 15% to 50% and water retenti on val ue reducti on between 7% and 35; and

h) dryi ng of the l ow pri mary fi nes content pul p i n dryi ng pul p machi nes wi th l ower consumpti on of dryi ng energy, thi s reducti on bei ng typi cal ly between 2% and 10% i n total energy when conpared with the energy used to dry commDn pul p.

2. Process, accordi ng to cl ai m l, characteri zed i n that the eel I ul osi c materi al i s sel ected from bl eached cel l ul ose, seni - bl eached eel I ul ose, unbl eached eel I ul ose, recycl ed f i bers and corrtoi nat i ons thereof.

3. Process, accordi ng to cl ai m l, characteri zed i n that it further i ncl udes, after step b) , the step d) referri ng to the obtai nment of a fi ber fracti on i n a percentage range from 90- 10% f i bers.

4. Process, accordi ng to cl ai m 3, characteri zed i n that sai d fi ber fracti on i s di rected to the step e) of producti on of eel I ul ose.

5. Process, accordi ng to cl ai m l, characteri zed i n that the nanocel I ul ose producti on process of step c) conpri ses the steps of:

c.1) thi ckeni ng the fi ne fracti on to 3-25% and

c.2) produci ng NFC nanocel I ul ose.

6. Process, accordi ng to cl ai m l, characteri zed i n that step b) i s carri ed out through a fracti onati ng syst em sel ect ed f romthe group conpri si ng pressuri zed basket screeni ng systerrs, fi ne parti cul ate recoveri ng washers, hydr ocycl ones and corrtoi nat i ons thereof.

7. Process, accordi ng to cl ai m l, characteri zed i n that the ref i ni ng energy of step c) may be associ ated wi t h enzymati c t r eat ment .

8. Process, accordi ng to cl ai m l, characteri zed i n that the high pri mary fi nes content pul p of step d) has oSR between 20 and 95, and water retenti on val ues between 140 and 690 per cent .

9. Process, accordi ng to cl ai m l, characteri zed i n that the nanof i bri I I ated eel I ul ose producti on process of step f ) i s associ ated with enzymati c treatment.

Description:
' PROCESS OF INTEGRATED PRODUCING NANOFI BRI LLAR CELULOSE AND HIGH DRAINAGE TAILORED MARKET PULP WTH REDUCED ENERGY

CONSUIVPTION . .

Fi el d of t he i nvent i on

The present i nventi on refers to the producti on of nanof i br i I I at ed cel l ul ose and tai l ored pul p for high drai nage abi l ity with reducti on i n the energy consumpti on for both st r earrs.

The process consi sts i n the separati on of a standard cel l ul ose pul p i nto di sti nct fracti ons with different drai ni ng and morphol ogi cal characteri sti cs, as wel l as the use of one fracti on to produce pri mary fi nes enri ched pul p designated to nanof i br i I I ar producti on and a high drai nabi l ity pul p desi gnated to paper market, contai ni ng l ow pri mary fi nes cont ent .

The process i n reference corrtoi nes the uni tary operati ons of pul p cooki ng, bl eachi ng, fi ber separati on, dryi ng of the high drai nage pul p fracti on and thi ckeni ng the high pri mary fi nes content pul p to a certai n consi stency so as to be abl e to proper nanof i br i I I at i ng it.

Background of the Inventi on

The producti on of eel I ul osi c pul p i nvolves several chemi cal and physi cal processes that result i n the separati on of the corrponents of the wood raw materi al (usual ly corrposed of cel l ul ose fi bers and fi bri l s, herri eel I ul oses, I i gni n mol ecul es and extractives or resi ns components).

Or i gi nal I y, t here i s broad si ze di st r i but i on of eel I ul osi c parti cl es i n the above-menti oned raw materi al s associ ated with the anatomi cal structures, and part of i t has reduced l ength. Duri ng the processes, mechani cal fri cti on i n equi pments such as pressure reducers, purrps and sti rrers whi ch, i n addi ti on to the cherri cal embr i 111 ement caused by cooki ng and bl eachi ng l i quors, causes the generati on or i ncrease of the content of these parti cl es i n the total resul t i ng f i bers. Those parti cl es are named as pri ary eel I ul osi c f i nes, bei ng di ff erenti ated to any fi ne parti cl es produced i n papermaki ng process due to the fact that they never suffered the effect of any ki nd of refi ni ng, whi ch are cal l ed secondary fi nes.

These f i nes produced i n t he pul pi ng and bl eachi ng process, al ong with the content of natural ly occurri ng fi nes i n raw materi al s, compose the total of parti cl es present i n the eel I ul osi c pul p of whi ch approxi mate di mensi ons are l ess than 200 nicrometers i n l ength.

The fi nes are defi ned as parti cl es capabl e of l i nearly traversi ng si eves of whi ch mesh i s l ess than 200 (apertures of 74 nicrometers) or whi ch are l ess than 200 ni crometers i n l ength (Tappi T261 cm 10, 2010 - Fi nes fracti on by weight of paper stock by wet screeni ng).

These parti cl es have hi gh specifi c area as wel l as high hydrophi l i e capaci ty, wherei n t hei r presence makes i t di f f i cul t to drai n the eel I ul osi c paste i n pul p and paper machi nes.

However, thei r smal l di mensi ons showed them to be a good starti ng materi al for the producti on of nanof i br i I I at ed cel l ul ose, wherei n the appl i cati on of a cel l ul ose paste enri ched wi th fi nes for thi s purpose takes pl ace wi th l ower energy cost and or better qual ity potenti al when corrpared to the use of the standard eel I ul osi c pul p. The producti on of fi bri M ated nanocel I ul ose consi sts of processi ng steps, wherei n refi ni ng i s the rrai n treatment. But there are al so combi nat i ons of refi ni ng treatments wi th cherri cal and/ or enzymati c treatments. The energy consunpti on, however, i s high due to the high refi ni ng energy consunpti on, and the cost of cherri cal s or enzymes for the producti on of f i br i I I at ed nanocel I ul ose. Due t o t hi s pr obi ern it i s i rrport ant to devel op new al t er nat i ves that can reduce energy consunpti on. In thi s new process descri bed herei n, it was studi ed the pot ent i a I of ni ni rri z i ng r ef i ni ng energy consunpt i on by changi ng the raw materi al for the producti on of nanof i br i I I at ed cel l ul ose. VShi I e most of the exi sti ng processes use regul ar ( non- f r act i oned or segregated) cel l ul ose pul p for the producti on of nanof i br i I I at ed cel l ul ose, i n this new process it i s defi ned a process for fracti onati ng the origi nal cel l ul ose pul p to obtai n a fracti on ri ch i n pri mary fi nes and shorter fi bers, whi ch i s then the base raw materi al for the producti on of nanof i bri I I ated eel I ul ose.

Internati onal appl i cat i on \AD 2013/ 188657 A1 , publ i shed on Decerrber 19, 2013, enti tl ed ' Energy effi ci ent process for prepari ng nanocel I ul ose fi bers_, descri bes a process that corrbi nes mechani cal treatment (refi ni ng) with chemical (ozone) and/ or enzymati c treatment. The descri bed process i s di rected to i ncrease energy effi ci ency, whi ch i s measured by the depol ymer i zat i on degree of the pul p and by the refi ni ng energy consunpti on to reach a certai n l evel of secondary fi nes (reachi ng a very high l evel of fi nes i s not a starti ng pul p materi al but a way to defi ne the qual i ty of the nanocel ul ose obtai ned after the refi ni ng process, generati ng hi gh amount of secondary fi nes). The descri bed process i s based on i ni ti ati ng from an ori gi nal common eel I ul os i c pul p, whi ch i s corrposed of f i br ous el ement s and not segr egat ed or f r act i onat ed. At no t i me the raw materi al for produci ng nanof i bri I I at ed cel l ul ose i s a source of pri mary fi nes type el ements associ ated wi th separati on of pul p phases, contrary to what i s proposed i n the process descri bed herei n.

Another method of produci ng nanof i br i I I at ed cel l ul ose i s descri bed i n Internati onal appl i cati on \AD 2015/171714, publ i shed on November 12, 2015, enti tl ed ' Hi gh eff i ci ency producti on of nanof i br i I I at ed cel l ul ose . . Di fferent from the present i nventi on, thi s document descri bes r ef i ni ng t r eat ment s of the eel I ul osi c pul p i n i ts ori gi nal form (and not i n the form of pri mary f i nes enri ched pul p). The method consi sts of the treatment of the pul p i n two steps, wherei n the fi rst step i s conducted wi th refi ni ng el ements di fferent from those used i n t he second step.

Internati onal appl i cati on VOf 2015/ 171714, publ i shed on Noverrber 12, 2015, enti tl ed ' Cel I ul ose f i bers, nanofi bri l s and ni crof i br i I s: t he mor phol ogi cal sequence of IVFC corrponent s f r om a pi ant physi ol ogy and f i ber t echnol ogy of vi ew_ al so descri bes t he di mensi ons of ni cr o and nanof i br i I I at ed eel I ul oses produced fromori gi nal common pul p, and not the benef i ts f r om gener at i ng a new and uni que starti ng materi al .

Internati onal appl i cat i on PCT/ FI 2010/050897, publ i shed on Noverrber 24, 2009, al so descri bes the hi gh refi ni ng energy consunpti on i n t he product i on of f i bri I I ated nanocel I ul ose and presents the use of a bl eachi ng agent (as an addi tive), but i t does not descri be, at any ti me, the use of pri mary fi nes enri ched pul p as raw materi al i n pl ace of non- f ract i oned eel I ul ose.

I nt er nat i onal appl i cat i on \AD2014106684 al so di scl oses t he high energy consunpti on i n the producti on of ni cr of i br i I I at ed cel l ul ose and presents a sol uti on with combi nati ons of processes by al ternati ng refi ni ng and washi ng, thus obtai ni ng an i ncrease i n consi stency to m ni mze energy consumpti on.

Internati onal appl i cat i on \AD 2014085730 A1 , publ i shed on J une 5, 2014, provi des a method of fracti onati ng bi orrass i nto different chemi cal components and cel l ul ose. The fracti onati on menti oned herei n refers to the separati on of the bi orrass corrponents: cel l ul ose, from I i gni n and herri eel I ul oses, and therefore, it does not have any si mi larity with the present i nventi on. The use of the eel I ul ose extracted i s the producti on of nanocryst al I i ne cel l ul ose, whi ch i s not an obj ect of the present i nventi on ei ther.

The research paper publ i shed by Qsong, S. 2013, et al , titl ed ' An approach to produce nano- 1 i gno- eel I ul ose from mechani cal pul p fi ne materi al s . , publ i shed on pages 472-479 from Nordi c Pul p & Paper Research J ournal ( NPPRJ ), Vol ume 28, descri bes a study i n whi ch mechani cal pul p i s separated and the shorter parti cl es are di rected to nano- 1 i gno- eel ul ose product i on t hr ough horrogeni zat i on. It t ot a I I y di f f ers f r om t he present i nventi on consi deri ng the i niti al raw materi al (mechani cal pul p) and even more i n the fi nal product produced: nano- 1 i gni n- eel I ul ose, due to the high contents of I i gni n i n its compositi on. Al so, the type of processi ng i s different, it bei ng performed through horrogeni zati on and not through ref i ni ng energy appl i cat i on. The ref i ni ng rrechani cal t reat ment i s, i n general , t he most commonly used process for generati on of nanof i br i I I at ed cel l ul ose, whi ch results i n signifi cant changes i n the rmr phol ogi cal characteri sti cs. The publ i cati ons known fromthe state of the art, al though menti oni ng f i nes as secondary f i nes, are onl y t hose generat ed dur i ng t he ref i ni ng t reat ment , whereas i n t he present i nvent i on t he f i nes are i n its total ity pri mary f i nes, f r act i onat ed f r om an or i gi nal eel I ul ose, t hus bei ng t he raw materi al for the producti on of nanof i bri I I ar cel l ul ose.

Summary of the Inventi on

It i s an obj ect of the present i nventi on to provi de a process of produci ng f i bri I I at ed nanocel I ul ose wi t h I ow energy consumpti on and al so a high drai n abi l ity market pul p compri si ng the steps of:

a) cooki ng and bl eachi ng of bi ornass, generati ng a mass ri ch i n eel I ul os i c and herri eel I ul osi c polymer chai ns, compri si ng very reduced amount of I i gni n and extractives.

b) sel ecti ng and di recti ng a eel I ul osi c materi al froma fi ber l i ne havi ng the fol l owi ng characteri sti cs:

b.1) average fi ber l ength: 0.3 to 2.5 mrn and b.2) pri mary fi ne content: 3% to 30% of fi nes by mass;

c) fracti onati ng the sel ected materi al by means of a f r act i onat i ng syst em

d) separati ng one strearn with the hi gh- pr i mary fi nes content materi al fracti on obtai ned i n step c), i n a percentage range from 10% to 90% of pri mary fi nes and consi stenci es of 0, 02% to 1% e) thi ckeni ng of thi s stream unti l consistenci es of 2% to 15%

f) submitti ng the thi ckened materi al to a nanof i br i I I at ed cel l ul ose producti on process, wherei n it i s subj ected to mechani cal refi ni ng energy, bei ng the energy consumpti on used for the generati on of the nanof i br i I I ar cel l ul ose smal l er than i n compari son with common eel I ul osi c pul p st ar t i ng mat er i al .

g) separati ng the other fracti on stream with l ower pr i rrary f i nes cont ent , so cal I ed hi gh dr ai nage pul p, pr esent i ng a massi c amount of fi nes of about 3 to 8% with signifi cant l ower resi stance to drai nabi l ity and water retenti on val ue, presenti ng a °SR reducti on of 15% to 50% water ret ent i on val ue reducti on between 7% and 35; and

h) dryi ng of the l ow pri mary fi nes content pul p i n dryi ng pul p machi nes wi th l ower consumpti on of dryi ng energy, thi s reducti on typi cal ly bei ng between 2% and 10% i n total energy when compared with the energy used to dry commDn pul p.

Bri ef Descri pti on of Drawi ngs

The structure and operati on of the present i nventi on, together wi th further advantages thereof may be better understood by reference to the acconpanyi ng drawi ngs and the f ol I owi ng descri pt i ons:

Figure 1 i l l ustrates a si mpl ifi ed scheme of obtai nment of products fromthi s i nventi on: nanof i br i I I ar cel l ul ose and high drai nage pul p for papermaki ng.

Figure 2 shows exampl es of the evol uti on of fi nes format i on ( measured by Bri tt J ar) and wi dt h of f i bers ( measured by opti cal morphol ogy) i n kraft pul p mi l l s. Figure 3 shows the characteri zati on of the fi nes materi al present i n the pul p sarrpl es (l ow fi nes content and hi gh fi nes content) i n extreme condi ti ons.

Figure 4 i l l ustrates the i pact of the fi nes i n drai nabi l ity of pul p i n l ab conditi ons.

Figure 5(a)-(c) shows a morphol ogi cal characteri zati on of processed pul p wi t h I ower f i nes content, showi ng i ts proper t i es and uni queness i n terms of pri mary f i nes content, wi t h i ncrease i n general fi ber l ength and wi dth of fi bers.

Figure 6(a)-(d) i l l ustrates the characteri zati on of pul p generated i n pi l ot scal e with l ower fi nes content, so cal l ed high drai nage pul p i n terrrs of resi stance to drai nage (°SR), water retenti on val ue, bul k and water absorpti on of a never dr i ed eucal ypt us pul p.

Fi gure 7 i I I ust rat es a pi I ot pi ant tri al data showi ng t he gai ns i n dryness after press with High Drai nage pul p cont a i ni ng reduced pri mary fi nes content, and showi ng the i ncrease i n the dryness content for the treated (high drai nage) pul p. The dryness i s a di rect measurement for energy consurrpti on. The higher the dryness, the smal l er the energy consurrpti on to dry a pul p i n a pul p machi ne.

Figure 8(a)-(e) shows the characteri zati on of hi gh fi nes content pul p, generated through pi l ot process, consi deri ng i ts morphol ogy and drai nabi l ity characteri sti cs.

Fi gure 9 shows hi gh resol ut i on ni croscopy of nanof i bri I I ar eel I ul ose based on 4 di ff erent types of pul ps, obtai ned i n I ab: Reference or Standard common pul p; High pri mary fi nes content pul p wi t h 25% pr i mary f i nes i n mass; Hi gh pr i mary f i nes cont ent pul p wi t h 50% pr i mary f i nes i n mass; Hi gh pr i mary f i nes cont ent pul p with 75% pri rrary fi nes i n rrass; pi l ot tri al Hi gh pri rrary f i nes cont ent pul p wi t h 37% showi ng t hat al l sarrpl es were abl e to generate nano di mensi ons i n the fi nal nanof i br i I I ar mat er i al .

Figure 10 shows a pi cture i n scal e of standard cel l ul ose fi bers, for reference i n conpari son with the nanof i br i I I ar eel I ul ose. It i s to be not ed t hat the scal e i s 10 ti rres hi gher than that shown i n figure 9.

Figure 11 i l l ustrates the average of the wi dth of nanofi bri l s from different pri mary fi nes content sampl es, i ncl udi ng the High Fi nes Content Pul p generated i n pi l ot conditi ons, showi ng that al l the Nanof i br i I I ar cel l ul oses generated have si rri I ar wi dth of nanofi bri l s average.

Figure 12(a) shows a conpari son of tensi l e strength of a standard pul p added with nanof i br i I I ar cel l ul ose i n order to eval uated the qual ity of the nanof i br i I I ar cel l ul ose i n terrrs of Tensi l e strength generati on i n a given pul p, showi ng that i n terrrs of qual ity of nanofi bri l s generated al l pul ps were si rri I ar.

Figure 12(b) shows a conpari son of resi stance to drai nage of a standard pul p added with nanof i br i I I ar cel l ul ose i n order to eval uated the qual i ty of the nanof i br i I I ar cel l ul ose i n terrrs of Schopper Ri egl er degree i ncrement generati on i n a given pul p, showi ng that i n terrrs of qual ity of nanofi bri l s generated al l pul ps were si rri I ar.

Figure 13 i l l ustrates the energy consumpti on i n kwh per metri c ton consumed to generate a given qual ity of nanof i br i I I ar cel l ul ose i n a pi l ot pl an with capaci ty to produce 2 tons per day, showi ng a signifi cant decrease i n the energy consumpti on when usi ng the high pri rrary fi nes content pul p as starti ng materi al for the nanocel I ul ose producti on.

Detai l ed Descri pti on of the i nventi on

Although the present i nventi on may be suscepti bl e to vari ous embodi ment s, there are shown i n the drawi ngs and i n the fol l owi ng detai l ed di scussi on, preferred embodi ments wi th the understandi ng that the present di scl osure i s to be consi dered as an exempl ifi cati on of the pri nci pl es of the i nventi on and i s not i ntended to I i rri t the present i nventi on to what i s i l l ustrated and descri bed herei n.

The present i nventi on refers to a process of produci ng nanof i br i I I at ed cel l ul ose with l ower energy consumpti on, and a pul p with hi gh drai nage abi l i ty. The energy consumpti on set herei n i s based on the same treatment performed on a reference (standard or corrmDn) pul p, compared to different l evel s of tri al pul ps accordi ng to what i s proposed i n the present i nvent i on.

The energy consumpti on reducti on i s possi bl e with the producti on of a raw materi al of cel l ul ose pri mary fi nes obtai ned by fracti onati ng of cel l ul ose pul p, fol l owed by a r ef i ni ng t reat ment .

Al t hough t he f i br i I I at ed nanocel I ul ose product i on process i nvolves a si mi l ar uni tary operati on, the present i nventi on refers to the new use of pr e- f r act i onat ed raw mat er i a I corrtoi ned wi t h uni que process par a met ers for t he product i on of eel I ul osi c materi al havi ng nanometri c di mensi ons with signifi cant reducti on of energy consumpti on. The preferred errbodi rrent of thi s i nventi on rel ates to a process of produci ng nanof i br i I I at ed cel l ul ose with I ow energy consumpti on conpri si ng the steps of:

a) cooki ng and bl eachi ng of bi orrass, generati ng a rrass ri ch i n cel l ul osi c and herri eel I ul osi c polymer chai ns, conpri si ng very reduced amount of I i gni n and extractives.

b) sel ecti ng and di recti ng a cel l ul osi c materi al froma fi ber l i ne havi ng the fol l owi ng characteri sti cs: b.1) average fi ber l ength: 0.3 to 2.5 mrn and b.2) pri mary fi ne content: 3% to 30% of fi nes by rrass;

c) fracti onati ng the sel ected materi al by means of a f r act i onat i ng syst em

d) separati ng one strearn with the hi gh-pri mary fi nes content materi al fracti on obtai ned i n step c), i n a percentage range from 10% to 90% of pri mary fi nes and consi stenci es of 0, 02% to 1%

e) thi ckeni ng of thi s stream unti l consistenci es of 2% to 15%

f) submitti ng the thi ckened materi al to a nanof i br i I I at ed cel l ul ose producti on process, wherei n it i s subj ect ed to mechani cal ref i ni ng energy, associ at ed or not wi t h enzymati c treatment, bei ng the energy consumpti on used for the generati on of the nanof i br i I I ar cel l ul ose smal l er than i n compari son with cornrron cel l ul osi c pul p starti ng materi al .

g) separati ng the other fracti on strearn with l ower pr i rrary f i nes cont ent , so cal I ed hi gh dr ai nage pul p, pr esent i ng a rrassi c amount of fi nes of about 3 to 8% preferably between 4% and 7% with signi fi cant l ower resi stance to drai nabi l i ty and wat er r et ent i on val ue, typi cal I y present i ng a °SR r educt i on of 15% to 50% more preferabl e between 20% and 40% water retenti on val ue reducti on between 7% and 35% more preferabl e between 10% and 25%

h) dryi ng of the l ow pri mary fi nes content pul p i n dryi ng pul p machi nes with l ow r consumpti on of dryi ng energy, thi s reducti on bei ng typi cal ly between 2% and 10% i n total energy when corrpared with the energy used to dry common pul p.

In step a), the eel I ul osi c materi al i s sel ected from cooked materi al s, and may be bl eached cel l ul ose, serri - bl eached cel l ul ose, unbl eached cel l ul ose, recycl ed fi bers and corrbi nat i ons thereof.

The process may consi der any eel I ul osi c pul p f i ber deri ved from short or l ong fi ber woods such as Eucalyptus, Coryrrbi a, Bi rch, Aspen, Pi nus, etc. , thei r resi dues such as bark, sawdust, etc., and al so any t ype of r ecycl ed f i bers, preferably of Eucalyptus and Coryrrbi a genders.

The pre-sel ected materi al i s then fracti onated i n step b) preferably through a fracti onati ng systern but not l i mited to pressuri zed basket screeni ng systerrs, fi nes parti cul ate recoveri ng washers or hydrocycl ones, i n one or more steps, wherei n combi nati ons of the aforementi oned equi pment may be used.

The high-pri mary fi nes materi al fracti on obtai ned from step b) i s then subj ected to thi ckeni ng and nanof i br i I I ar eel I ul ose producti on process, i n whi ch i t wi I I be subj ected to refi ni ng energy so that i ts el ement si zes are reduced to nanomet r i c f ract i ons.

The fracti on of fi bers with l ower pri mary fi nes content, contai ni ng a massi c amount of f i nes of about 3 to 8% pref era bl y between 4% and 7% with signi fi cant l ower resi stance to drai nabi l ity and water retenti on val ue.

In step d) , the high pri rrary fi nes content pul p i s characteri zed by °SR between 20 and 95; and water retenti on val ues between 140 and 690 per cent.

In step g) , the absol ute vari abl es specifi c from Eucalyptus treatments i n the Hi gh Drai nage Pul p after pul p dryer are: fi nes content between 3%to 8, 5% preferably between 4 to 7% water retenti on val ue between 90 and 140 g/g, more preferabl e between 110 and 130 and °SR between 12 and 19, more preferabl e between 14 and 17.

Figure 1 descri bes bri efly the processual steps from raw materi al sel ecti on unti l the producti on of the

Nanof i br i I I at ed cel l ul ose and the high drai nage pul p.

Figure 2 descri bes the i ncrease i n the fi nes content i n two different kraft rri I I s, showi ng the crescent profi l e of fi nes content accordi ng to the course of the process. The profi l e may be sl ightly different case by case for each rri I I due to the ki nd of equi pments, i ntensity of cooki ng and mechani cal energy suffered by the fi bers.

Li kewi se, the wi dth of the fi bers al so decreases due to the chenical peel i ng reacti ons al so contri buti ng to the i ncrease and generati on of the f i ber category so cal I ed pri rrary f i nes.

Figure 3 shows the ni croscopi c aspect of the fi bers (i n the right) and pri rrary fi nes (i n the l eft). A high amount of short f i bers and s ma I I el ements i s present i n t he pri rrary f i nes sarrpl e and barely seen i n the sarrpl es whose materi al was removed, al l owi ng the high drai nabi l ity of the pul p trough physi cal and chenical i nproved fl ow through the voi d vol umes cr eat ed.

Figure 4 shows the i rrpact of the pri rrary fi nes (measured by Britt J ar i n mass percentage) i n drai nabi l ity aspects represented by Schopper Ri gl er degree (°SR) and water retenti on val ue. The val ues cl early i ndi cates the high i mpact of the presence of pri mary fi nes i n the drai nabi l ity of the fi bers.

Figure 5 shows the morphol ogi cal characteri sti c of the high drai nage pul p, with reduced pri rrary fi nes content to i ts half, and i ncrease of fi ber l ength and wi dth.

Figure 6 show the drai nabi l ity and absorpti on properti es characteri zati on of pul p generated i n pi l ot scal e wi th l ower fi nes content. The properti es of the so cal l ed High drai nage pul p i n terms of resi stance to drai nage (°SR), water retenti on val ue, bul k and water absorpti on demonstrates that consi derabl e gai ns i n the drai nabi l ity properti es are present, signifyi ng high potenti al for energy consumpti on reducti on i n the dryi ng of thi s pul p i n pul p and paper machi nes. The absence of fi nes al so creates higher bul k pul p, al l owi ng the pul p to absorb more water per gram of pul p.

Figure 7 shows the possi bl e gai ns i n dryness after pul p machi ne press, al l owi ng the energy savi ng i n between 2 to 10% for pul p dryi ng.

Figure 8 shows the properti es of the hi gh pri mary fi nes content pul p, generated through pi l ot processes. In figure 8 a), the pri mary fi nes content shown has val ues obtai ned from one of the conditi ons used i n pi l ot trial s, and can be higher or l ower dependi ng of the need and technol ogy set up used. The i rrpact on drai nabi l i ty as demonstrated i n items b and c i s enourrrous, showi ng very high drai nage and water retenti on val ues caused by the presence of the pri mary f i nes i n the pul p. The i tems d and e show the average fi bers l ength and wi dth measured, demonstrati ng that the fi bers contai ned i n the materi al s are al so shorter and narrower that the regul ar ones.

Figure 9 shows exampl es of i mages showi ng the wi dth of the nanof i bri I s generated f romi ncreasi ng pri mary f i nes content sarrpl es.

The average of its wi dth was done by eval uati ng 400 measurements for each sarrpl e, fromat l east 10 high resol uti on i mages and resulted i n very si ni l ar wi dth for al l the sarrpl es, showi ng that the qual ity of the nanof i br i I I at ed cel l ul ose i s the same, as seen i n Figure 11.

Figure 12 shows the characteri zati on of the potenti al of modi fyi ng properti es i n a given standard pul p by addi ng Nanof i br i I I ar cel l ul ose i n terrrs of Tensi l e Strength and Resi stance to drai nage i ncrease.

As can be seen from figure 12, there i s no difference bet ween t he qua I i t y of t he nanof i br i I I at ed eel I ul ose gener at ed from standard pul p and from the high pri mary fi nes content pul p.

Figure 13 shows the energy consumpti on i n k\Ah per metri c ton consumed to generate a given qua I i ty of nanof i br i I I ar eel I ul ose i n a pi l ot pl an wi th capaci ty to produce 2 tons/day. By conventi on, and based on l iterature and machi ne constructi on for nanocel I ul ose obtai nment trough refi ni ng energy (pl ease see reference \AD 2013/188657) when 90% of the parti cl es si ze i n l ength i s smal l er than 200 micrometers, obtai ned i n morphol ogi cal measurements, the product can be consi dered a nanof i br i I I at ed eel I ul ose accor di ng to t he def i ni t i on of havi ng at l east one of its three di mensi ons between 1 and 100 nanometers accordi ng to ISO/TS 20477:2017 - Nanot echnol ogi es St andar d terrrs and thei r def i ni t i on f or eel I ul ose nanomat er i a I .

In the chart 13, it i s shown that the energy necessary to the obtai nment of high quantity of smal l er parti cl es i s rruch l ower than the standard pul p. Consi deri ng the standard val ue of 90% t he t ot a I net energy reduces to its ha I f. It i s possi bl e al so to see that if necessary, the appl i cati on of energy can be such that the qual ity of the nanof i br i I I at ed eel ul I ose can be i ncrease (through the i ncrease of the amount of fi bers i n smal l er si ze than 200 ni cr omet er s) .

Thus, al though only some embodi ments of the present i nventi on have been shown, it wi I I be understood that several onissi ons, substituti ons and changes can be made by a person ski l l ed i n the art, wit hout depart i ng f r om t he spi r i t and scope of thi s i nventi on. The embodi ments descri bed shoul d be consi dered i n al I respects only as i l l ustrative and not i n a rest r i ct i ve manner.

It i s expressly provi ded that al l corrtoi nat i ons of the el ements that performthe same functi on substanti al ly the same way to achi eve the same results are withi n the scope of the i nventi on. Substi tuti on of el ements i n an embodi ment descri bed to another are al so ful ly corrpri sed and cont errpl at ed.

It shoul d be also understood that some of the drawi ngs are not necessari ly i n scal e, and are conceptual i n nature. The i ntenti on i s, therefore, to be l i ited, as i ndi cated by the scope of the attached cl ai rrs.