LMS Biobleaching Process Parameter Studies Process Parameter - PowerPoint PPT Presentation

LMS Biobleaching Process Parameter Studies Process Parameter Studies Art J Ragauskas Art J. Ragauskas Institute of Paper Science and Technology

Pulp Bleaching • Purpose of bleaching is 2-fold: – to remove the residual lignin – to brighten the pulp • Current bleaching technologies • Current bleaching technologies consist of: – O 2 , ClO 2 , H 2 O 2 , & O 3 – Capital intensive – Limited selectivity – D has environmental limitations D has environmental limitations – New bleaching agents needed!

LACCASE-MEDIATED BIOBLEACHING BIOBLEACHING

Laccase: Overview Laccase OH Type II Cu 1+ Cu 2+ O 2 1+ Cu Cu 1+ 2+ Cu Cu 2+ O N His His N O Type III N His His N H H H S Cys S Cys Cu 1+ Cu 2+ Type I Fully Oxidized Fully Reduced Oxidoreductase enzyme y E.I. Solomon et al • Reduces O 2 to H 2 O •Catalysis occurs due to 4 2 concomitantly oxidizes concomitantly oxidizes copper atoms/active site • MW varies 65 000 140 000 • MW varies 65,000-140,000. • Active sites near surface • Carbohydrate content ~10-45 (% wt). Active sites on surface

Laccase: Overview • Proposed to be involved in lignin biosynthesis • Oxidize a wide array of phenolic substrates • Oxidize a wide array of phenolic substrates OCH 3 HO HO OR OR 2 OH Laccase/O 2 HO O O O OCH 3 OCH 3 OCH 3 MeO OH H 3 CO OCH 3 OMe OH MeO OMe HO OH OH OMe CO 2 H H 3 CO H 3 CO OCH 3 OH OH Hi Higuchi, Wood Sci. Techn., 24, 22(1990) hi W d S i T h 24 22(1990)

Pulp Fiber Low MW Co-factor - Mediator Laccase Biobleaching O 2

Laccase Biobleaching g LMS-Process LIGNIN LIGNIN MEDIATOR OX MEDIATOR LACCASE LACCASE O2 O MEDIATOR LIGNIN H2O LACCASE OX OX OX

Laccase Biobleaching Conditions LMS(E) C di i LMS(E) • LMS: 45 o C, 1-2 h, 5-20% csc, Laccase Lac/ABTS Lac/HBT Lac/NHA Lac/VA pH 4 pH 4 - 6, 1-4% mediator, +40 psi 6 1 4% mediator +40 psi 60 • E: 70 o C, 1-3 h, 1-2% NaOH 50 50 elignificatin SO 3 NH 4 40 S N N N N S H 4 NO 3 S 30 ABTS % De 20 OH O 10 N N OH O O N 0 N N S SW Kraft f HW Kraft f HN NH N OH O Highly selective for lignin, little HBT VA NHA Call -1995 Amman 1997 degradation of pulp carbohydrates degradation of pulp carbohydrates Ragauskas et al: Enzyme and Micro. Technol., 23, 422 (1998), TAPPI J., 83(9), 66(2000); J. Wood Chem. Technol., 20(2), 169(2000)

LMSVA Biobleaching High/Low Kappa Kraft Pulps Kraft P lps 50 Conditions 45 45 LMS 40 5.4 x 10 5 U laccase/gr od pulp 35 45 o C 2h 120 psi O 45 o C, 2h, 120 psi O 2 , 9% csc, 9% csc 30 30 Kappa # med.= VA 25 20 EP 15 15 80 o C, 1.5 h, 0.5% H 2 O 2 , 10 10% csc 5 0 0 SW1 SW1-LMS(EP) SW2 SW2-LMS(EP) HW1 HW1-LMS(EP) HW2 HW2-LMS(EP) LMS applicable to low and hi h k high kappa kraft pulps k ft l

LMS VA Biobleaching: Lignin Reactivity Start LMS(EP) mmol/g lignin 1.2 1 2 1 OMe OH OMe 0 8 0.8 OH 0.6 0.4 0.2 0 SW(50 0 K) SW(50.0 K) SW(27 5 K) SW(27.5 K) SW(50.0 K) SW(50 0 K) SW(27 5 K) SW(27.5 K) LMS LMS reactivity primarily via phenolics, especially C5 noncondensed in SW ti it i il i h li i ll C5 d d i SW Delving into the Fundamental LMS Delignification of High-Kappa Pulps. Biotechnology in the Pulp and Paper Industry, 151-164 (2002).

Biobleaching High and Low Kappa Pulps Biobleaching High and Low Kappa Pulps Pulp % Delign. % Yield SW kappa 50 43 99.9 SW kappa 28 62 100.0 65 a HW kappa 27 pp 98.6 70 a HW kappa 11 99.1 a k a kappa primarily hexenuronic acids i il h i id

Yield Kappa Relationships 50 50 LMS(E* 48 d, % ) 50(LMS)E*DED ( ) n Wood 46 50(OO) Pulping 50(OO)DED 44 Yield on 42 30DED 40 40 Y 30ODED 38 0 10 20 30 40 50 60 Kappa Number

LMS VA Bleaching Sequence Studies LMS VA Bleaching Sequence Studies • LMS based sequences 90 e equal to ECF in final l t ECF i fi l 80 brightness properties 70 rightness 60 • LMS yield gains occur 50 from higher selectivity for from higher selectivity for TAPPI Br 40 high kappa pulps 30 20 • What is not yet 10 established: established: 0 ) E ) ) ) ) ) ) k k O ) % % % O % % % O c c D O • NPE effects o o P P 6 8 0 4 6 8 ) t O . . . t E . . . E s s 0 0 1 0 0 0 n n ( ( P ( ( ( ( ( ( ) D D D D D D D w w S E O E E E ) ) ) o o M ( O O O ) r r O • Mixing effects D D D B L S B P P P ) ) ) ( M M O O O O O O E E E E E E S S L L ( ( ( ( ( ( P P P P P P M M D D D ( E E E S L O O O ( ( ( M ) ) ) • Carryover effects O O O S S S L M M M L L L ( ( ( S S S M M M L L L

NPE’s on LMS NPE s on LMS • Most LMS studies have been preformed using ‘clean systems’ • All kraft pulps and process streams have nonprocesss elements present (Ca Mg Fe Mn elements present (Ca, Mg, Fe, Mn, Cu, Ni, etc) Exp Design Exp. Design • Perform LMS(E) and repeat with NPEs • Compare delignification and viscosity properties of biobleached pulps l

>> no observed NPE impact on delignification LMS VA Bleaching: Effects of NPEs Kapp pa # VA 20 25 30 35 40 40 45 50 55 60 BS B LMS( LMS-0.1%NaCl( S(E) LMS-1.0%NaCl( l(E) LMS-1% MNSO4(E l(E) LMS-1%NiSO4(E (E) g LMS-1%FeSO4(E 4(E) LMS-1%CuSO4( 4(E) LMS-1%MgSO4( 4(E) 4(E)

>> slight NPE impact on pulp viscosity Visco osity/cP LMS VA Bleaching: Effects of NPEs 20 25 30 35 40 45 50 55 60 B S L L M M L S VA M ( E S ) - 0 . 1 % N N a a L C C M l ( E S ) - 1 . 0 % N N a a L C C M l ( S E - 1 ) % M n S S O O L 4 M ( E S ) - 1 % N i S S O O L 4 M ( E S g ) - 1 % F e S S O O L 4 M ( E S ) - 1 % ` C u S S O O L M 4 ( S E - ) 1 % M g S S O O 4 ( E )

LMS VA Bleaching: Effect of Mixing LMS VA Bleaching: Effect of Mixing Objective bj i Assess the impact of mixing on an LMS stage Experimental Procedure Biobleaching Sequence LMS(EPO) - LMS:Lac: 1.4 x 10 7 U/10 gr pulp, 45 min., 4.5 pH, 4% VA, 120 psi O 2 LMS:Lac: 1.4 x 10 U/10 gr pulp, 45 min., 4.5 pH, 4% VA, 120 psi O 2 Quantum reactor, 10% csc, 55 o C, -(E+P+O): 70 o C, 1 h, 10% csc, 60 psi, 0.5% H 2 O 2 , 2.5% NaOH ( ) , , , p , 2 , 2

LMS VA Bleaching: Effect of Mixing LMS Mixing Conditions: Quantum g Q A. 600 rpm for 10 sec every 2 min. B B. 1200 rpm for 5 sec every 2 min. 1200 rpm for 5 sec every 2 min C. 2400 rpm for 2.5 sec every 2 min. [constant refining energy] Pulp Kappa # Viscosity/cP TAPPI Brightness Brownstock 33.3 30.4 25.9 A(E+P+O) 14.6 23.6 34.2 B(E+P+O) 14.4 23.2 34.2 C(E+P+O) 14.3 23.1 33.3

LMS VA Bleaching: Effect of Mixing g g VA LMS Mixing Conditions: i i di i D. 600 rpm for 10 sec every 2 min. E. 3600 rpm for 10 sec every 2 min. [variable mixing energy] Pulp P l K Kappa # # Vi Viscosity/cP it / P TAPPI B i ht TAPPI Brightness Brownstock 33.3 30.4 25.9 D(E+P+O) 14.2 23.8 32.9 E(E+P+O) 14.0 22.7 32.6

LMS VA Bleaching: Effect of Mixing LMS Mixing Conditions: F F. 600 rpm for 10 sec every 2 min. – 20% csc (Quantum) 600 rpm for 10 sec every 2 min – 20% csc (Quantum) G. 2400 rpm for 10 sec every 2 min. – 20% csc (Quantum) H. ≈ 48 rpm- constant – 10% csc (Parr reactor, paddle mixer) H 48 10% (P ddl i ) Pulp Kappa # Viscosity/cP Brownstock 33.3 30.4 F(E+P+O) F(E+P+O) 14 2 14.2 22 9 22.9 G(E+P+O) 14.1 23.6 H(E+P+O) H(E+P+O) 16 3 16.3 -- Provide efficient mixing is occurring in a LMS-stage, detrimental shear effects were not observed

Black Liquor Carryover on LMS q y • Most LMS studies have been preformed using ‘clean systems’ • All kraft pulps are delignified in the presence of black liquor carryover and this is know to influence O D and P this is know to influence O, D and P. • Effect on LMS is unknown Exp Design Exp. Design • Perform LMS(E) with and without Black liquor carryover • Compare delignification and viscosity properties of biobleached pulps

LMS VA Bleaching: Effect of Carryover 50 40 # Kappa 30 20 BS 0% Solids 0.1% Solids 0.5% Solids 1.0% Solids 5.0% Solids % Solids carryover added 2% charge of VA in LMS VA

LMS VA Bleaching: Effect of Carryover LMS VA Bleaching: Effect of Carryover 50 4% VA 40 30 Kappa # 20 10 0 Brownstock 1% 5% 10% 20% 30% Carryover Carryover Carryover Carryover Carryover Carryover levels of 10% black liquor solids are not detrimental towards an LMS stage

LMS - BIOBLEACHING LMS BIOBLEACHING Effect of Temperature – pH on LMS

LMS VA Bleaching: Effect of Temperature g p VA 50 40 # Kappa 30 30 20 BS [LMS- [LMS- [LMS- [LMS- [LMS- [LMS- 45](E) 55](E) 65](E) 75](E) 85](E) 95](E) Temperature limitations of laccase employed limited LMS stage to ∼ 20–75 o C

LMS VA Bleaching: Effect of pH 50 45 40 pa # Kapp 35 35 30 25 20 [LMS-2.9](E) BS S [LMS-4.7](E) E) [LMS-5.1](E) E) [LMS-5.3](E) E) [LMS-6.4](E) E) [LMS-6.9](E) E) [LMS-7.0](E) E) [LMS-7.1](E) E) [LMS-8.9](E) E) E) pH limitations of laccase employed limit LMS stage to ∼ 3 - 5