- •Recovered Paper and Recycled Fibers
- •Isbn: 3-527-30999-3
- •Introduction
- •Isbn: 3-527-30999-3
- •Isbn: 3-527-30999-3
- •2006, Isbn 3-527-30997-7
- •Volume 1
- •Isbn: 3-527-30999-3
- •4.1 Introduction 109
- •4.2.5.1 Introduction 185
- •4.3.1 Introduction 392
- •5.1 Introduction 511
- •6.1 Introduction 561
- •6.2.1 Introduction 563
- •6.4.1 Introduction 579
- •Volume 2
- •7.3.1 Introduction 628
- •7.4.1 Introduction 734
- •7.5.1 Introduction 777
- •7.6.1 Introduction 849
- •7.10.1 Introduction 887
- •8.1 Introduction 933
- •1 Introduction 1071
- •5 Processing of Mechanical Pulp and Reject Handling: Screening and
- •1 Introduction 1149
- •Isbn: 3-527-30999-3
- •Isbn: 3-527-30999-3
- •Isbn: 3-527-30999-3
- •Isbn: 3-527-30999-3
- •Introduction
- •Introduction
- •Isbn: 3-527-30999-3
- •1 Introduction
- •1 Introduction
- •1 Introduction
- •1 Introduction
- •1 Introduction
- •1 Introduction
- •150.000 Annual Fiber Flow[kt]
- •1 Introduction
- •1 Introduction
- •Introduction
- •Isbn: 3-527-30999-3
- •Void volume
- •Void volume fraction
- •Xylan and Fiber Morphology
- •Initial bulk residual
- •4.2.5.1 Introduction
- •In (Ai) Model concept Reference
- •Initial value
- •Validation and Application of the Kinetic Model
- •Inititial
- •Viscosity
- •Influence on Bleachability
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Introduction
- •International
- •Impregnation
- •Influence of Substituents on the Rate of Hydrolysis
- •140 116 Total so2
- •Xylonic
- •Viscosity Brightness
- •Xyl Man Glu Ara Furf hoAc XyLa
- •Initial NaOh charge [% of total charge]:
- •Introduction
- •Isbn: 3-527-30999-3
- •Introduction
- •Isbn: 3-527-30999-3
- •Introduction
- •Introduction
- •Isbn: 3-527-30999-3
- •In 1950, about 50% of the global paper production was produced. This proportion
- •4.0% Worldwide; 4.2% for the cepi countries; and 4.8% for Germany.
- •1150 1 Introduction
- •1 Introduction
- •1 Introduction
- •Virgin fibers
- •74.4 % Mixed grades
- •Indonesia
- •Virgin fibers
- •Inhomogeneous sample Homogeneous sample
- •Variance of sampling Variance of measurement
- •1.Quartile
- •3.Quartile
- •Insoluble
- •Insoluble
- •Insoluble
- •Integral
- •In Newtonion liquid
- •Velocity
- •Increasing dp
- •2Α filter
- •0 Reaction time
- •Increasing interaction of probe and cellulose
- •Increasing hydrodynamic size
- •Vessel cell of beech
- •Initial elastic range
- •Internal flow
- •Intact structure
- •Viscosity 457
- •Isbn: 3-527-30999-3
- •1292 Index
- •Visbatch® pulp 354
- •Index 1293
- •1294 Index
- •Impregnation 153
- •Viscosity–extinction 433
- •Index 1295
- •1296 Index
- •Index 1297
- •Inhibitor 789
- •1298 Index
- •Index 1299
- •Impregnation liquor 290–293
- •1300 Index
- •Industries
- •Index 1301
- •1302 Index
- •Index 1303
- •Xylose 463
- •1304 Index
- •Index 1305
- •1306 Index
- •Index 1307
- •1308 Index
- •In conventional kraft cooking 232
- •Visbatch® pulp 358
- •Index 1309
- •In prehydrolysis-kraft process 351
- •Visbatch® cook 349–350
- •1310 Index
- •Index 1311
- •1312 Index
- •Viscosity 456
- •Index 1313
- •Viscosity 459
- •Interactions 327
- •1314 Index
- •Index 1315
- •Viscosity 459
- •1316 Index
- •Index 1317
- •Xylose 461
- •Index 1319
- •Visbatch® pulp 355
- •Impregnation 151–158
- •1320 Index
- •Index 1321
- •1322 Index
- •Xylan water prehydrolysis 333
- •Index 1323
- •1324 Index
- •Viscosity 459
- •Index 1325
- •Xylose 940
- •1326 Index
- •Index 1327
- •In selected kinetics model 228–229
- •4OMeGlcA 940
- •1328 Index
- •Index 1329
- •Intermediate molecule 164–165
- •1330 Index
- •Viscosity 456
- •Index 1331
- •1332 Index
- •Impregnation liquor 290–293
- •Index 1333
- •1334 Index
- •Index 1335
- •1336 Index
- •Impregnation 153
- •Index 1337
- •1338 Index
- •Viscose process 7
- •Index 1339
- •Volumetric reject ratio 590
- •1340 Index
- •Index 1341
- •1342 Index
- •Index 1343
- •1344 Index
- •Index 1345
- •Initiator 788
- •Xylose 463
- •1346 Index
- •Index 1347
- •Vessel 385
- •Index 1349
- •1350 Index
- •Xylan 834
- •1352 Index
Impregnation
HOT
DISPLACEMENT
HEATING
AND COOKING
COLD
DISPLACEMENT
DISCHARGE
Fig. 4.131 Steps of the Rapid Displacement Heating (RDH) cooking cycle [1,2].
accumulator B. Eventually, the pulp is discharged from the digester by use of pressurized
air or by pumping [1,2].
4.2.8.2.5 SuperBatch
The typical SuperBatch tank farm also consists of three pressurized accumulators
and two atmospheric tanks (Fig. 4.132). Again, the liquor tanks are staged in temperature
and fresh alkali is supplied from the hot white liquor tank. Steam is used
for controlling the temperature of both hot white liquor and hot black liquor in
the tank farm, as well as for bringing the digester to cooking temperature.
The SuperBatch cooking cycle is shown schematically in Fig. 4.133. After chip
filling, impregnation liquor (i.e., black liquor of below 100 °C) is used for impregnation.
During the subsequent hot black liquor treatment, the impregnation
liquor is displaced from the digester back to the impregnation liquor tank. The
cooking liquor is then charged in the form of hot white liquor and hot black
liquor, and the digester is brought to cooking temperature by steam injection into
the circulation line. White liquor can be added during the cooking phase to control
the alkali balance. After cooking, wash filtrate displaces the hot black liquor
first into the primary hot black liquor accumulator and then into the secondary
accumulator. Eventually, the pulp is discharged by pumping [3].
4.2 Kraft Pulping Processes 373
HBL
I
HBL DIG WF
II
IL HWL
WHITE LIQUOR
CHIPS
PULP
BLACK
LIQUOR
WASH
FILTRATE
WW
HW
STEAM
STEAM
Fig. 4.132 Simplified SuperBatch process flowsheet.
IL = impregnation liquor; HBL I/II = primary/secondary hot
black liquor; HWL= hot white liquor; DIG = digester;
WF = wash filtrate; WW = warm water; HW = hot water [3].
CHIPS
AIR
CHIP FILL
SUPERBATCH
COOKING
CYCLE
Impregnation
HOT BLACK
LIQUOR
TREATMENT
HEATING
AND COOKING
COLD
DISPLACEMENT
PUMP
DISCHARGE
IL
HBL I
IL,
HBL II
WF
HBL I,
HBL II
PULP
WF
COOKING LIQUOR
CHARGE
HWL +
HBL I
HBL II
STEAM
Fig. 4.133 Steps of the SuperBatch cooking cycle [3].
374 4 Chemical Pulping Processes
4.2.8.2.6 Continuous Batch Cooking (CBC)
The CBC tank farm consists of two pressurized accumulators and two atmospheric
tanks (Fig. 4.134). There is no hot white liquor tank, and steam is used only for
heating of liquors in the tank farm. The temperatures and alkali concentrations of
the impregnation liquor and the cooking liquor are adjusted in the tank farm in
their respective tanks. There are also no digester circulation lines. During impregnation
and cooking, the liquor circulates from the tank to the digester and back to
the tank [4].
IL WBL CL DIG WF
WHITE
LIQUOR
CHIPS
PULP
BLACK
LIQUOR
WASH
FILTRATE
WW
HW
STEAM
Fig. 4.134 Simplified CBC process flowsheet.
IL = impregnation liquor; WBL= warm black liquor;
CL = cooking liquor; DIG = digester; WF = wash filtrate;
WW = warm water; HW = hot water [4].
After chip filling, impregnation liquor (IL) is charged to the digester. Once the
digester is hydraulically full, the liquor circulates back to the impregnation liquor
tank. Following the impregnation step, cooking liquor (CL) is pumped to the
digester and the displaced liquor first continues to return to the impregnation
liquor tank and then is switched to the warm black liquor tank (Fig. 4.135). All
heating of the digester contents is carried out by the supply of hot cooking liquor.
During cooking, the displaced liquor is returned to the cooking liquor tank. Subsequent
to cooking, the wash filtrate displaces hot black liquor first into the hot
black liquor accumulator and then to the warm black liquor accumulator. Eventually,
the pulp is discharged from the digester by pumping [4].
Since the CBC cook is controlled by alkali concentrations rather than by alkali
charges, the determination of chip weight in the digester is not an issue. With its
straightforward design, the CBC process features the least number of sequence
steps per cooking cycle, which makes its operation the easiest of all displacement
cooking processes.
4.2 Kraft Pulping Processes 375
PULP
WF
WF
CL, WBL
CL
IL, WBL
CHIPS
AIR
CHIP FILL
CBC
COOKING
CYCLE