IMPROVING DEINKED PULP IMPROVING DEINKED PULP QUALITY BY OXIDATION WITH QUALITY BY OXIDATION WITH TEMPO TEMPO by Julie Leroux Centre intégré en pâte et papier Université du Québec à Trois-Rivières
Outline Outline Introduction Objectives Approach Experimental Results Conclusions Acknowledgements
Introduction 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
Introduction Introduction Solution? : � 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
Problematic 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
Objectives 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)
Approach 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
Experimental Experimental Deinked Pulp Oxidation with Tempo Filtration and washing Optimized Oxidized Pulp Mixtures with TMP pulp Handsheet Making and testing
Experimental Experimental Trial No. TEMPO TEMPO NaBr NaBr NaOCl NaOCl (g) (mmol/g) (g) (mmol/g) (mL) (mmol/g) 1 0.025 0.0019 0.76 0.123 6 0.083 2 0.025 0.0019 1.52 0.246 6 0.083 3 0.025 0.0019 2.54 0.411 6 0.083 4 0.025 0.0019 4.75 0.770 6 0.083 5 0.025 0.0019 0.76 0.123 12 0.166 6 0.025 0.0019 1.52 0.246 12 0.166 7 0.025 0.0019 2.54 0.411 12 0.166 8 0.025 0.0019 4.75 0.770 12 0.166 9 0.025 0.0019 0.76 0.123 37 0.512 10 0.025 0.0019 1.52 0.246 37 0.512 11 0.025 0.0019 2.54 0.411 37 0.512 12 0.025 0.0019 4.75 0.770 37 0.512 13 0.025 0.0019 0.76 0.123 75 1.038 14 0.025 0.0019 1.52 0.246 75 1.038 15 0.025 0.0019 2.54 0.411 75 1.038 16 0.025 0.0019 4.75 0.770 75 1.038 17 0.025 0.0019 0.76 0.123 150 2.075 18 0.025 0.0019 1.52 0.246 150 2.075 19 0.025 0.0019 2.54 0.411 150 2.075 20 0.025 0.0019 4.75 0.770 150 2.075
Results Results Optimization Pulp mixtures
Results-Optimization Results-Optimization Carboxylic Groups 450 Carboxyl content in 400 pulp (mmol/kg) 350 300 250 200 150 100 0 0.083 0.166 0.512 1.038 2.075 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
Results Results Breaking Length 5.5 Breaking length (Km) 5.0 4.5 4.0 3.5 3.0 0 0.083 0.166 0.512 1.038 2.075 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
Results Results Burst Index Burst index (kPa*m 2 /g) 3.3 3.1 2.9 2.7 2.5 2.3 2.1 1.9 1.7 1.5 0 0.083 0.166 0.512 1.038 2.075 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
Results Results Tear Index Tear index (mN*m 2 /g) 11.0 10.0 9.0 8.0 7.0 6.0 0 0.083 0.166 0.512 1.038 2.075 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
Results Results Brightness 65 Brightness iso (%) 60 55 50 45 40 0 0.083 0.166 0.512 1.038 2.075 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
Results Results Residual Ink (ERIC) 280 260 240 ERIC (ppm) 220 200 180 160 140 120 100 0 0.083 0.166 0.512 1.038 2.075 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
Conclusions-Optimization 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
Results-Pulp Mixtures Results-Pulp Mixtures Breaking Length 5.5 Breaking length (km) 5.0 4.5 4.0 3.5 3.0 2.5 Bl 10 30 50 80 100 TMP Deinked pulp (%) Blank TMP Untreated High carboxyl Low carboxyl
Results Results Burst Index Burst index (kPa*m 2 /g) 3.5 3.0 2.5 2.0 1.5 1.0 Bl 10 30 50 80 100 TMP Deinked pulp (%) Blank TMP Untreated High carboxyl Low carboxyl
Results Results Tear Index Tear index (mN*m 2 /g) 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 Bl 10 30 50 80 100 TMP Deinked pulp (%) Blank TMP Untreated High carboxyl Low carboxyl
Results Results Brightness 59.0 Brightness ISO (%) 58.0 57.0 56.0 55.0 54.0 53.0 52.0 51.0 50.0 Bl 10 30 50 80 100 TMP Deinked pulp (%) Blank TMP Untreated High carboxyl Low carboxyl
Results Results Residual Ink (ERIC) 250.0 200.0 ERIC (ppm) 150.0 100.0 50.0 0.0 Bl 10 30 50 80 100 TMP Deinked pulp (%) Blank TMP Untreated High carboxyl Low carboxyl
Conclusions-Pulp Mixtures 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.
Acknowledgements 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
QUESTIONS QUESTIONS
Mechanism Mechanism CH 2 OH CH 2 OH O O O O N O OH OH O OH OH pâte originale NaBr NaOCl N O TEMPO COONa COONa NaCl NaOBr O O O O OH OH O N OH OH OH pâte oxydée
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