EcoFracSmart: A new stock preparation process for testliner - PowerPoint PPT Presentation

EcoFracSmart: A new stock preparation process for testliner Karl-Johan Grundström, Marco Lucisano STFI-Packforsk AB Box 5604 – SE-11486 Stockholm (Sweden ) Bernt Bergström, Annika Bjärestrand Eva Larsson Noss Lyckeby Industrial Hans-Olof Lindh Roland Selin Owe Sänneskog Smurfit Kappa Lagamill JLR Pulping Systems Läckeby Water 2007-09-24 8 th Research Forum on recycling 2007 turning science into reality

Outcome Introduce a stock preparation process for testliner , based on ecoefficient coarse screening and hydrocyclone fractionation of the furnish for differentiated treatment of the fractions.

Outcome In an industrial installation : - 35-40 kWh/t as electricity. - 130 kWh/t as steam. In pilot trials : � 60% furnish: no upgrade by refining. � 60% furnish: excellent papermaking fibres.

The papermaking process Illustration: CEPI Sustainability Report 2005

Recycling in Europe Strategic goal 2005 56% Recycling rate 2005 54.6% Strategic goal 2010 66%

Energy in papermaking Source: CEPI Sustainability Report 2005

Raw materials

Goal of the project Demonstration of process technology for stock preparation in a recycled paper mill: – Decreasing energy consumption. – Improving product properties. – Simplifying stock preparation.

• Separate fibre according to end-product properties. • Limit energy intensive processes. Hydrocyclone fractionation EcoFracSmart = EcoSmart + FracSmart Pulper + Hydration + Multifunctional Screen • Minimize energy consumption in the early steps. • Separate impurities as early as possible. • Gentle mechanical treatment of the fibre material.

The project Papermill OCC / Consumer packaging OCC / Consumer packaging Pulping Pulping Screening Screening Papermill Refining Refining Hydrocyclone Cleaning Cleaning fractionation Cleaning Refining Production of Production of two two -ply testliner -ply testliner Pilot Production of two -ply testliner - Repulping Repulping • Addition of starch • Screen Screen • Impulse drying • fractionation fractionation Pilot Refining Refining Hydrocyclone Production of Production of trial two two -ply testliner -ply testliner - • Addition of starch • • • Impulse drying Reference trial

Multifunctional screen Combines the functions of: • Defibration, • Separation of heavy contaminants, • Coarse screening, • Fine screening.

Multifunctional screen • A modified pressure screen: – Lower defibration energy in the pulper. – Hydration between the pulper and the screen. – The feed flow is hydrated but poorly defibrated material. – The rotor has a defibration action in the entrance section of the screen. • Simplification of the process flow.

Multifunctional screen

Original installation PM Pulper FS FF PM Curved screen Pulper Disp Disp PM Broke PM

Original reject system Water Press Pulper

With multifunctional screen Water Multifunctional Screen Chest Pulper Chests Refining Cleaners To PM Chest

Installed power Standard Multifunctional [kW] Screen Fractionating Screen 121 - Fractionating Screen 24 - Dispersion 375 - Multifunctional Screen - 219 Total 520 219 � - 301 kW

Stock preparation energy Trad EcoSmart Energy consumption 320±40 280±40 (excluding dispersion) [kWh/t] Energy consumption 450±40 280±40 (including dispersion) [kWh/t]

Effect of the new process • Lower energy consumption. • Simplified process layout. • Good papermachine runnability. • Lower contaminants � better surface. • Higher ash content � somewhat lower strength properties.

Raw material – OCC 250 um 250 μ m Micrograph Phase contrast microscopy

Papermill OCC / Consumer packaging OCC / Consumer packaging Pulping Pulping Screening Screening Papermill Refining Refining Hydrocyclone Cleaning Cleaning fractionation Cleaning Refining Production of Production of two two -ply testliner -ply testliner Pilot Production of two - -ply testliner Repulping Repulping • Addition of starch • Screen Screen • Impulse drying • fractionation fractionation Pilot Refining Refining Hydrocyclone Production of Production of trial two two -ply testliner -ply testliner - • Addition of starch • • • Impulse drying Reference trial

Hydrocyclone fractionation Q = 950 l/min 60% C = 0.38% Filtrate P = 3.6 kg/min Fine fraction C = 3.3% P = 3.7 kg/min 72°SR 39°SR Q = 1400 l/min C = 0.66% P = 9.2 kg/min 40% Coarse fraction Fractionating C = 3.0% hydrocyclones P = 2.5 kg/min 14°SR Cleaners Q = 34 l/min Sand C = 1.3% Heavy reject P = 0.44 kg/min

Reference: screen fractionation P = 14 kg/min Q = 700 l/min 34°SR C = 0.9% 48% Short fibre fraction C = 0.028% C = 3.9% P = 6 kg/min 59°SR Q = 1400 l/min C = 1.1% 52% Q = 700 l/min Long fibre C = 1.3% fraction C = 4.1% C = 0.39% P = 8 kg/min 19°SR

Fractionation, Impurities 1,8 1,6 1,4 Hydrocyclones Screen 1,2 Impurities [%] 1,0 0,8 0,6 0,4 0,2 0,0 Feed Fine fraction Unrefined 70 kWh/t 120 kWh/t Coarse fraction

Tensile index 60 Hydrocyclones Screen 50 Tensile index [Nm/g] 40 30 20 10 0 Feed Fine fraction Unrefined 70 kWh/t 120 kWh/t Coarse fraction

Surface roughness 1000 Surface roughness [ml/min] 800 600 400 200 0 Feed Fine fraction Unrefined 70 kWh/t 120 kWh/t Coarse fraction

Pilot scale papermaking Fourdrinier table Roll press Twin-wire former Shoe presses • Two-ply testliner: – Twin-wire: 50 g/m 2 (fine/short fraction) – Fourdrinier: 75 g/m 2

SCT index Hydrocyclones Screen 30 Impulse drying 25 SCT index [Nm/g] 20 15 10 5 0 Commercial 120 kWh/t 70 kWh/t 120 kWh/t 70 kWh/t 70 kWh/t 120 kWh/t testliner No starch Starch X Starch A

Surface roughness 1800 1600 Surface roughness [ml/min] 1400 1200 1000 Impulse drying 800 600 400 200 0 Commercial 120 kWh/t 70 kWh/t 120 kWh/t 70 kWh/t 70 kWh/t 120 kWh/t testliner No starch Starch X Starch A

Results and conclusions • New screening section installed and tested: – -35-40 kWh/t electricity. – -130 kWh/t steam. • Hydrocyclone fractionation tested successfully: – Testliner from OCC: energy saving > 20 kWh/t. – All properties unaffected or improved. – Synergy with selective dosage of starch. • Process integration assessed on testliner from OCC: – No technically unsolvable open issues. – Large optimization window.

Acknowledgements Financial support from STEM, The Swedish Energy Agency, is gratefully acknowledged.