IMPROVING DEINKED PULP QUALITY BY OXIDATION WITH TEMPO

Size: px

Start display at page:

Download "IMPROVING DEINKED PULP QUALITY BY OXIDATION WITH TEMPO"

Edwina Farmer
6 years ago
Views:

1 IMPROVING DEINKED PULP QUALITY BY OXIDATION WITH TEMPO by Julie Leroux Centre intégré en pâte et papier Université du Québec à Trois-Rivières

2 Outline Introduction Objectives Approach Experimental Results Conclusions Acknowledgements

3 Introduction Critical crisis for the Canadian pulp and paper industry Devastating effects on its future economic growth Challenges High value of the Canadian $ vs the US $ Rising costs: Fuel, energy,wood chips Low prices and overcapacity for several grades Newsprint demand in US is decreasing Quebec: Coulombe report

4 Solution? : Introduction Use more deinked pulp (DIP) To compensate for the reduction in virgin fibres supply To reduce production costs DIP is largely used for Newsprint Fine papers Tissue papers Boards

5 Problematic DIP is not used in value added papers Lower bonding ability of deinked fibres Lower water re-swelling properties Chemical and mechanical treatments affect fibre properties Residual ink Aging of offset inks Ink redeposition during repulping Reduced optical properties (Grey shade) Contaminants Adhesives, waxes and latexes Stickies (macro and micro stickies) Affect pulp quality and papermachine runnability

6 Objectives To increase DIP usage in value added papers Must improve both optical and physical properties of deinked fibres To study the oxidizing potential of TEMPO Improve strength and optical properties of deinked fibres Establish optimal conditions for oxidation Determine the effect of addition deinked fibres to TMP (physical and optical properties)

7 Approach Tempo oxidation of DIP improved strength properties Determine optimum concentration of NaBr and NaOCl With optimum concentrations Make handsheets with oxidized deinked fibres and TMP Determine physical and optical properties

8 Experimental Deinked Pulp Oxidation with Tempo Filtration and washing Optimized Oxidized Pulp Mixtures with TMP pulp Handsheet Making and testing

9 Experimental Experimental NaOCl (mmol/g) NaOCl (ml) NaBr (mmol/g) NaBr (g) TEMPO (mmol/g) TEMPO (g) Trial No.

10 Results Optimization Pulp mixtures

11 Results-Optimization Carboxylic Groups Carboxyl content in pulp (mmol/kg) NaOCl added (mmol/g) Blank 0.12 mmol NaBr/g 0.25 mmol NaBr/g 0.41 mmol NaBr/g 0.77 mmol NaBr/g

12 Breaking Length Breaking length (Km) Results NaOCl added (mmol/g) Blank 0.12 mmol NaBr/g 0.25 mmol NaBr/g 0.41 mmol NaBr/g 0.77 mmol NaBr/g

13 Results Burst Index Burst index (kpa*m 2 /g) NaOCl added (mmol/g) Blank 0.12 mmol NaBr/g 0.25 mmol NaBr/g 0.41 mmol NaBr/g 0.77 mmol NaBr/g

14 Tear Index Tear index (mn*m 2 /g) Results NaOCl added (mmol/g) Blank 0.12 mmol NaBr/g 0.25 mmol NaBr/g 0.41 mmol NaBr/g 0.77 mmol NaBr/g

15 Results Brightness 65 Brightness iso (%) NaOCl added (mmol/g) Blank 0.12 mmol NaBr/g 0.25 mmol NaBr/g 0.41 mmol NaBr/g 0.77 mmol NaBr/g

16 Residual Ink (ERIC) ERIC (ppm) Results NaOCl added (mmol/g) Blank 0.12 mmol NaBr/g 0.25 mmol NaBr/g 0.41 mmol NaBr/g 0.77 mmol NaBr/g

17 Conclusions-Optimization Increase of both NaOCl and NaBr Higher amounts of carboxyl groups Improvement is important for high concentration of NaOCl Breaking length and burst were improved Tear was reduced Brightness was slightly decreased ERIC was slightly reduced

18 Results-Pulp Mixtures Breaking Length Breaking length (km) Bl TMP Deinked pulp (%) Blank TMP Untreated High carboxyl Low carboxyl

19 Results Burst Index Burst index (kpa*m 2 /g) Bl TMP Deinked pulp (%) Blank TMP Untreated High carboxyl Low carboxyl

20 Results Tear Index Tear index (mn*m 2 /g) Bl TMP Deinked pulp (%) Blank TMP Untreated High carboxyl Low carboxyl

21 Results Brightness Brightness ISO (%) Bl TMP Deinked pulp (%) Blank TMP Untreated High carboxyl Low carboxyl

22 Residual Ink (ERIC) Results ERIC (ppm) Bl TMP Deinked pulp (%) Blank TMP Untreated High carboxyl Low carboxyl

23 Conclusions-Pulp Mixtures Higher proportions of oxidized deinked fibres improved Breaking length, burst and tear Brightness was slightly improved ERIC were higher for all trials Low carboxyl pulp can be use as fibres reinforcement.

24 Acknowledgements Financial supports Natural Sciences and Engineering Research Council of Canada (NSERC) Canada Research Chair in Value-added Paper And Bruno Chabot, Ph.D Claude Daneault, Ph.D

25 QUESTIONS

28 Mechanism CH 2 OH O CH 2 OH O N O O OH O OH O NaOCl NaBr OH pâte originale OH N O TEMPO NaCl NaOBr COONa O COONa O O OH O OH O N OH OH OH pâte oxydée

Keywords: TEMPO-mediated oxidation; Thermomechanical pulp; Carboxylic group; Lignin; Paper strength

Keywords: TEMPO-mediated oxidation; Thermomechanical pulp; Carboxylic group; Lignin; Paper strength Selective TEMPO-Mediated Oxidation of Thermomechanical Pulp Pu Ma and Huamin Zhai * Carboxylic acid groups were introduced onto thermomechanical pulp (TMP) long fiber surfaces by 2,2,6,6,- tetramethylpiperidine-1-oxyl