Post on 14-Dec-2015
Effects of Final Bleaching Stage Using Hydrogen Peroxide and Peracetic Acid (eq.) in the ECF
Bleaching of Acacia D0EOPD1 Kraft Pulps
Presenter : Dede Ermawan (st110031)Adviser : Dr. Jiri Basta (Chairman)
Dr. Mousa M. Nazhad Dr. Esa Lehtinen
Presented on Master Theses Competetion, AIT, 16th May 2011
INTRODUCTION
Background
Problem •Typically ECF Bleaching O-D0-EOP-D1-D2•The high chemical charge result in high cost and high environmental load.
Proposal •Looking for chemical to reduce chemical consumption which more effective in final bleaching and less environmental load
Objectives•To optimize the existing process and reintroduce new agents to minimize the cost and environmental load•To optimize D2 stage•To examine new chemicals (P and PAA)
EXPERIMENTAL DESIGN
Experimental Plan
RESULTS
D1 Stage Optimization
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.075.0
77.0
79.0
81.0
83.0
85.0
87.0
89.0
91.0
D1 Experiments
D1 Experiment Target 85% Target 87% Target 89%
Chlorine Dioxide as active cholrine (% On Pulp)
Bri
gh
tne
ss
(%
ISO
)
D1 stage: T=70°C, t=150 min, Consistency=10%, end pH= 3.5-4.5
A PulpB Pulp
C Pulp
D2 Stage Results
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.080
82
84
86
88
90
92
94
Chlorine Dioxide (D2) Experiments
A Pulp B Pulp C Pulp Target
Chlorine Dioxide as active chlorine (% on pulp)
Bri
gh
tne
ss
(%
ISO
)
D2 stage: T=70°C, t=180 min, Consistency=10%, end pH= 4.0-4.5
P Stage Results
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.00
102030405060708090
100
Final P Experiments
A Pulp B Pulp C Pulp Target
Hydrogen Peroxide Charge (% on Pulp)
Bri
gh
tne
ss
(%
ISO
)
P stage: T=90°C, t=90 min, Consistency=10%, Mg= 0.05%, end pH= 11-12
PAA Stage Results
0.00 0.10 0.20 0.30 0.40 0.500
102030405060708090
100Final Paa Experiments
A Pulp B Pulp C PulpA Pulp Change pH 11-12 B pulp Change pH 11-12 C Pulp Change pH 11-12Target 90% Brightness
Peracetic acid Charge (% on Pulp)
Brig
htne
ss (%
ISO
)
PAA stage: T=80°C, t=90 min, Consistency=10%, end pH= 5-6PAA/P stage: additonal: T=80°C, t=90 min, Consistency=10%, end pH= 11-12
Evaluation
Pulp Quality
CostEnvironmental
Brightness Reversion
90.6
90.0 90.2 90.2 90.0 90.1 90.0 90.1 90.1 90.1
88.8
87.688.1 88.0
88.7 88.588.9 89.0 88.8
88.6
-2.04-2.67
-2.38 -2.48
-1.51 -1.69-1.29 -1.25 -1.40 -1.62
-4.00
-2.00
0.00
2.00
4.00
6.00
8.00
10.00
80.0
82.0
84.0
86.0
88.0
90.0
92.0
D2 Mill A Final D B Final D C Final D A Final P B Final P C Final P A Final PAA/P B Final PAA/P B Final PAA
Brightness & Brightness Reversion
Initial Brightness (%ISO) Brightness reversion 105 deg celcius 4h (%ISO) Percentage reversion (%)
% IS
O%
Re
versio
n
Extractive Content
D2 Mill A Final D B Final D C Final D A Final P B Final P C Final P A Final PAA/P
B Final PAA/P
B Final PAA
0.000.050.100.150.200.250.300.350.400.450.50
0.260.31 0.30 0.31
0.09 0.08 0.07 0.05 0.050.10
Acetone Extractable Matter (%)
Properties of pulps
Kind of Pulps
Fiber Morphology Optical Properties Strength Properties
No. of Fibers
(Mill./g)
Average Length (mm)
Coarseness (mg/m)
Fines Content
(%weight)
Fiber Width (µm)
Opacity s coefficient (m²/kg)
k coefficient
(m²/kg)
Tear Index (mN.m2/g)
Tensile Index
(Nm/g)z-span Nm/g
D2 Mill 29.55 0.630 0.072 3.34 17.45 83.50 55.07 0.16 4.64 22.91 120.0
A Final D 27.23 0.640 0.077 3.29 17.30 83.05 53.69 0.16 5.22 23.88 129.0
B Final D 29.14 0.640 0.072 3.32 17.35 83.46 54.15 0.16 5.06 25.42 132.0
C Final D 28.26 0.635 0.075 3.29 17.35 83.27 54.89 0.16 4.69 24.71 128.0
A Final P 27.96 0.635 0.075 3.15 17.20 82.74 54.43 0.17 5.41 23.59 125.0
B Final P 28.74 0.635 0.073 3.20 17.20 82.75 54.76 0.16 5.40 24.44 130.0
C Final P 29.24 0.635 0.072 3.31 17.30 81.92 51.33 0.17 5.68 24.95 123.0
A Final PAA/P 29.88 0.650 0.069 3.17 ND 82.10 52.34 0.16 5.26 24.20 123.0
B Final PAA/P 28.74 0.640 0.073 3.28 ND 83.01 53.44 0.16 5.74 24.07 123.0
B Final PAA 29.34 0.640 0.071 3.18 ND 83.03 54.38 0.16 4.83 24.13 122.0
Average 28.81 0.638 0.073 3.25 17.31 82.88 53.85 0.16 5.19 24.23 125.5
S. deviation 0.80 0.005 0.002 0.07 0.09 0.53 1.20 0.00 0.39 0.71 4.0
Max 29.88 0.650 0.077 3.34 17.45 83.50 55.07 0.17 5.74 25.42 132.0
Min 27.23 0.630 0.069 3.15 17.20 81.92 51.33 0.16 4.64 22.91 120.0
Evaluation
Pulp Quality
CostEnvironmental
Evaluation of Environmental parameters
0.00 0.20 0.40 0.60 0.80 1.000.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
Plot of Bleaching Process vs COD (kg/tp)
Final PAA D1 D2 Final PFinal PAA/P
%Charge Chemical on Pulp
COD
(kg/
tp)
0.00 0.20 0.40 0.60 0.80 1.000.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
Plot of bleaching process vs Suspended Solid (kg/tp)
D1 D2 Final PFinal PAA/P Final PAA
Charge of Chemical (% on Pulp)
Susp
ende
d So
lid (k
g/tp
)
0.25 0.90 0.40 0.10D1 D2 Final P Final
PAA/P
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
Chloride content (kg/tp) in Bleaching filtrate
BAT emission of Bleached kraft pulp:
Evaluation
Pulp Quality
CostEnvironmental
Cost Analysis
No Process
D1 Final D Final Bleaching
Cost Per tp (USD)
*6000 tp per day (USD)aCl (kg/tp) NaOH
(kg/tp) aCl (kg/tp) NaOH (kg/tp)
1 A Final D 1.5 0 10.0 0.5 4.950 29,6992 B Final D 2.5 0 9.0 0.5 4.950 29,6993 C Final D 9.0 0.5 1.5 0 4.532 27,190
No Process
D1 Final P Final Bleaching
Cost Per tp (USD)
*6000 tp per day (USD)aCl (kg/tp) NaOH
(kg/tp)Hydrogen peroxide (kg/tp)
NaOH (kg/tp)
1 A Final P 1.5 0 6.0 10 9.427 56,5642 B Final P 2.5 0 4.0 10 7.846 47,0743 C Final P 9.0 0.5 1.5 7.5 7.504 45,026
No Process
D1 Final PAA Final Bleaching
Cost Per tp (USD)
*6000 tp per day (USD)aCl (kg/tp) NaOH
(kg/tp)Peracetic
acid (kg/tp)
NaOH (kg/tp)
1 A Final PAA/P 1.5 0 1.5 10 5.677 34,0642 B Final PAA/P 2.5 0 1.0 10 5.346 32,0743 B Final PAA 2.5 0 2.0 1.5 4.466 26,7944 C Final PAA 9.0 0.5 0.4 1.0 4.784 28,706
D2
P
PAAD1
CONCLUSIONS
Conclusions
Some alternative method to produce 90% ISO brightness pulp had been investigated. Those are D0EOPD1D2, D0EOPD1P, D0EOPD1PAA, D0EOPD1PAA/P
Final Bleaching DPAA/P produce pulp which the best brightness stability, followed by DP, DPAA and DD respectively.
Extractive content of DPAA/P pulp is the lowest, followed by DP, DPAA, and DD respectively.
No major differences in morphology of fiber and strength properties of paper.
Final bleaching of DD sequences produce lowest COD but higher SS and chloride content. While, DP and DPAA produce lower SS but higher COD , but it can be treated easily in the waste water treatment plant.
DP and DPAA/P stages are significantly more expensive , while cost of DPAA maybe of interested when comparing with DD.
Thank you