Recovered Paper Yield Estimate Recovered Paper Yield Estimate Using - - PowerPoint PPT Presentation

Recovered Paper Yield Estimate Recovered Paper Yield Estimate Using Laboratory + Mill Using Laboratory + Mill Accounting Accounting Data Data

By: By: Robert Robert de de Jong Jong 2 2 Fiber Consulting Fiber Consulting

2 2

Objective Objective

• To get maximum quantity of RP to the PM

To get maximum quantity of RP to the PM headbox without affecting product quality headbox without affecting product quality

• Remove contaminants:

Remove contaminants:

• Metal, plastic, wet strength, stickies

Metal, plastic, wet strength, stickies

• Remove undesirable components:

Remove undesirable components:

• Such as ash, RP fines, solubles

Such as ash, RP fines, solubles

• Minimize losses of good fibers from process,

Minimize losses of good fibers from process, which will increase residue disposal costs which will increase residue disposal costs

• Track RP yield to control process economics

Track RP yield to control process economics

3 3

Introduction Introduction

• Yield = (output tons / input tons) %

Yield = (output tons / input tons) %

• “

“As is As is” ” or bone dry (BD) basis

• r bone dry (BD) basis
• Accounting data subject to errors:

Accounting data subject to errors:

• Incorrect scale weights

Incorrect scale weights

• Inventory differences

Inventory differences

• Broke accounting discrepancies

Broke accounting discrepancies

• Yield per RP Grade not identified

Yield per RP Grade not identified

Numbers in Blue are Spreadsheet Variables Numbers in Blue are Spreadsheet Variables

4 4

Hypothetical Mill Example Hypothetical Mill Example

• Produces

Produces 21,000 21,000 “ “as is as is” ” tons / month tons / month

• Furnish =

Furnish = 30,000 30,000 “ “as is as is” ” tons / month tons / month

• SWL

SWL = = 20% 20%

• CBK

CBK = = 20% 20%

• ONP

ONP = = 20% 20%

• Wetlap Pulp

Wetlap Pulp = = 20% at PM 20% at PM

• Broke

Broke = = 20% at PM 20% at PM

5 5

Assumed Moisture Content Assumed Moisture Content

6% 6% 9% 50% 7% 7% 0% 10% 20% 30% 40% 50% 60% SWL CBK ONP Wetlap Broke Product % MOISTURE

Moisture content

The 50% moisture content of Wetlap lowers yield The 50% moisture content of Wetlap lowers yield

6 6

“ “As is As is” ” Yield Yield

Tons/mo. Moist. Tons/mo. Moist.

As is Furnish Comp As is Furnish Comp. .

As is As is Cont. Cont. Input DP = Input DP = 20% 20% SWL SWL 6,000 6,000 6% 6% 20% 20% CBK CBK 6,000 6,000 6% 6% 20% 20% ONP ONP 6,000 6,000 9% 9% Input PM= Input PM= 20% 20% Wetlap Wetlap 6,000 6,000 50% 50% 20% 20% Broke Broke 6,000 6,000 7% 7%

TOTAL INPUT = TOTAL INPUT = 30,000 30,000 OUTPUT = OUTPUT = 21,000 21,000

7% 7%

LOSSES = LOSSES = 9,000 9,000 YIELD = 21,000/30,000 = YIELD = 21,000/30,000 = 70% 70%

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Recalculated on BD Basis Recalculated on BD Basis

Tons/mo. Tons/mo.

BD Furnish Comp BD Furnish Comp. . BD BD

Input DP = Input DP = 22.3% SWL 22.3% SWL 5,640 5,640 22.3% CBK 22.3% CBK 5,640 5,640 22.6% ONP 22.6% ONP 5,460 5,460 Input PM= 11.8% Wetlap Input PM= 11.8% Wetlap 3,000 3,000 22.0% Broke 22.0% Broke 5,580 5,580

TOTAL INPUT = TOTAL INPUT = 25,320 25,320 OUTPUT = OUTPUT = 19,530 19,530 LOSSES = LOSSES = 5,790 5,790 YIELD = 19,530 / 25,320 = YIELD = 19,530 / 25,320 = 77.1% 77.1%

Numbers in Blue are Spreadsheet Variables Numbers in Blue are Spreadsheet Variables

8 8

Typical Average Laboratory Data Typical Average Laboratory Data

RP Grade RP Grade

6 Cut Rej 6 Cut Rej. . Solubles Solubles BJ F&A BJ F&A SWL SWL 0.2 % 0.2 % 4 % 4 % 26 % 26 % CBK CBK 0.4 % 0.4 % 6 % 6 % 33 % 33 % ONP ONP 1.4 % 1.4 % 1 % 1 % 27 % 27 % Wetlap Pulp Wetlap Pulp 0 % 0 % 2.5 % 2.5 % 20 % 20 % Broke Broke 0.1 % 0.1 % 1 % 1 % 11 % 11 %

• Fin. Product
• Fin. Product

0 % 0 % 1 % 1 % 11 % 11 %

Numbers in Blue are Spreadsheet Variables Numbers in Blue are Spreadsheet Variables

9 9

Allocating Coarse Rejects Allocating Coarse Rejects

• Coarse Rejects to landfill =

Coarse Rejects to landfill = 180 180 BD tons / mo BD tons / mo (according to accounting data) (according to accounting data)

• Good fiber content =

Good fiber content = 30 30% % (according to Lab) (according to Lab)

• Allocate Coarse Rejects

Allocate Coarse Rejects Input Input (% 6 cut rejects x BD RP tons + (% 6 cut rejects x BD RP tons + 30 30%) %)

• Compare with accounting data

Compare with accounting data

• Distribute unaccounted tons

Distribute unaccounted tons

30% good fiber per lab, 180 tons per accounting 30% good fiber per lab, 180 tons per accounting

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6 Cut Rejects in Furnish + Product 6 Cut Rejects in Furnish + Product

(BD tons/mo) (BD tons/mo)

Product Product 180 180 29 = 29 = 35 + 35 + 116 + 116 + Total Total 9 9 1 1 = = 2 2 + + 6 6 + + Broke Broke Wetlap Wetlap 119 119 19 = 19 = 23 + 23 + 76 + 76 + ONP ONP 35 35 6 = 6 = 7 + 7 + 23 + 23 + CBK CBK 17 17 3 = 3 = 3 + 3 + 11 + 11 + SWL SWL Losses Losses Unacc. Unacc. 30% 30% Fiber Fiber Lab Lab Calc. Calc. RP RP Grade Grade

11 11

Allocating Solubles Allocating Solubles

• Calculate input solubles

Calculate input solubles (% solubles x BD RP tons ) (% solubles x BD RP tons )

• Calculate solubles in Product

Calculate solubles in Product (% solubles x BD Product tons ) (% solubles x BD Product tons )

• Allocate output solubles

Allocate output solubles (according to BD furnish composition) (according to BD furnish composition)

• Input

Input – – output tons = solubles per furnish

• utput tons = solubles per furnish

component component

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Solubles in Furnish + Product Solubles in Furnish + Product

(BD tons/mo) (BD tons/mo)

195 195 Product Product 554 554 195 195 13 13 = = 43 43 56 56 -

• Broke

Broke 52 52 = = 23 23 75 75 -

• Wetlap

Wetlap 13 13 = = 42 42 55 55 -

• ONP

ONP 295 295 = = 44 44 338 338 -

• CBK

CBK 182 182 = = 44 44 226 226 -

• SWL

SWL Losses Losses Tons Tons In Prod In Prod Lab Lab Calc. Calc. RP RP Grade Grade

13 13

Calculate BJ Fines & Ash Calculate BJ Fines & Ash in PM Furnish and DIP in PM Furnish and DIP

Assume: Assume:

• Wetlap + Broke F & A retained

Wetlap + Broke F & A retained 90% 90% (determine when deink plant is down) (determine when deink plant is down)

• Calculate F & A in Product

Calculate F & A in Product

• Calculate F & A from wetlap + broke

Calculate F & A from wetlap + broke

• Difference is from DIP

Difference is from DIP

• Allocate DIP F & A

Allocate DIP F & A (according to DIP BD furnish) (according to DIP BD furnish)

*=90% PM fines & ash retained; rest is removed *=90% PM fines & ash retained; rest is removed

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BJ F & A in PM Furnish + Product BJ F & A in PM Furnish + Product

(BD tons/mo) (BD tons/mo) 1,056 1,056 DIP DIP 2,148 2,148 2,148 2,148 Product Product 1,092 1,092 61 61 552* = 552* = 614 614 -

• Broke

Broke 60 60 540* = 540* = 600 600 -

• Wetlap

Wetlap BJ BJ Losses Losses Tons in Tons in Product Product Lab Lab Calc. Calc. RP RP Grade Grade

2148 2148 -

• 1092 = 1056 in DIP

1092 = 1056 in DIP

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BJ F & A in DIP BJ F & A in DIP

(BD tons/mo) (BD tons/mo)

3,867 3,867 1,092 1,092 61 61 552 = 552 = 614 614 -

• Broke

Broke 60 60 540 = 540 = 600 600 -

• Wetlap

Wetlap 1,130 1,130 1,056* 1,056* 344 = 344 = 1,474 1,474 -

• ONP

ONP 1,505 1,505 356 = 356 = 1,861 1,861 -

• CBK

CBK 1,111 1,111 356 = 356 = 1,466 1,466 -

• SWL

SWL BJ BJ Losses Losses Sub Sub-

• Total

Total Tons in Tons in Product Product Lab Lab Calc. Calc. RP RP Grade Grade

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Calculate Residue Losses Calculate Residue Losses

Assume: Assume:

• Residue contains

Residue contains 20% 20% good fiber good fiber (according to lab samples) (according to lab samples)

• Accounting reports

Accounting reports 4,900 4,900 tons BD residue tons BD residue (according to truck weights x average dry (according to truck weights x average dry solids content of residue) solids content of residue)

• Add BJ losses +

Add BJ losses + 20% 20% fiber losses fiber losses

• Compare with accounting BD residue losses

Compare with accounting BD residue losses

• Distribute unaccounted losses

Distribute unaccounted losses

20% Fiber in residue per Lab, 4,900 tons per acc. 20% Fiber in residue per Lab, 4,900 tons per acc.

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Residue Losses Residue Losses

(BD tons/mo) (BD tons/mo)

4,900 4,900 390 = 390 = 752 + 752 + 3,758 + 3,758 + 78 78 4 4 = = 12 12 + + 61 61 + + Broke Broke 76 76 4 = 4 = 12 + 12 + 60 + 60 + Wetlap Wetlap 1,432 1,432 76 = 76 = 226 + 226 + 1,130 + 1,130 + ONP ONP 1,907 1,907 101 = 101 = 301 + 301 + 1,505 + 1,505 + CBK CBK 1,407 1,407 74 = 74 = 222 + 222 + 1,111 + 1,111 + SWL SWL Residue Residue Losses Losses Unacc. Unacc. 20% 20% Fiber Fiber BJ BJ Losses Losses RP RP Grade Grade

18 18

Calculate Total Losses Calculate Total Losses

• Add losses per grade and per category

Add losses per grade and per category

• Coarse rejects + good fiber

Coarse rejects + good fiber

• Solubles

Solubles

• Fines & ash + good fiber

Fines & ash + good fiber

• Compare with accounting BD losses

Compare with accounting BD losses

• BD accounting losses

BD accounting losses – – calculated losses = calculated losses = unaccounted losses unaccounted losses

• Distribute unaccounted losses proportionally

Distribute unaccounted losses proportionally

25,320 BD tons input 25,320 BD tons input -

• 19,530 output = 5,790 tons

19,530 output = 5,790 tons

19 19

Summary of Losses per Grade Summary of Losses per Grade

(BD Tons/mo) (BD Tons/mo) 5,790* 5,790* 156 = 156 = 4,900 + 4,900 + 554 + 554 + 180 + 180 + 102 102 3 3 = = 78 78 + + 13 13 + + 9 9 + + Broke Broke 131 131 4 = 4 = 76 + 76 + 52 + 52 + 0 + 0 + Wetlap Wetlap 1,606 1,606 43 = 43 = 1,432 + 1,432 + 12 + 12 + 119 + 119 + ONP ONP 2,299 2,299 62 = 62 = 1,907 + 1,907 + 295 + 295 + 35 + 35 + CBK CBK 1,651 1,651 44 = 44 = 1,407 + 1,407 + 182 + 182 + 18 + 18 + SWL SWL Total Total Losses Losses Unacc. Unacc. F&A F&A Soluble Soluble Coarse Coarse Rejects Rejects RP RP Grade Grade

20 20

Calculate Yield Calculate Yield

• Subtract BD losses per grade from BD input

Subtract BD losses per grade from BD input per grade = BD output per grade per grade = BD output per grade

• BD yield per grade =

BD yield per grade =

• (BD output / BD input )%

(BD output / BD input )%

• “

“As is As is” ” yield per grade = yield per grade =

• (

(“ “as is as is” ” output /

• utput / “

“as is as is” ” input )% input )%

21 21

BD Yield Calculation BD Yield Calculation

19,530 19,530 Product Product 77.1% 77.1% 19,530 19,530 5,790 5,790 25,320 25,320 98.2% 98.2% 5,478 5,478 102 102 5,580 5,580 Broke Broke 95.6% 95.6% 2,869 2,869 131 131 3,000 3,000 Wetlap Wetlap 70.6% 70.6% 3,854 3,854 1,606 1,606 5,460 5,460 ONP ONP 59.2% 59.2% 3,341 3,341 2,299 2,299 5,640 5,640 CBK CBK 70.7% 70.7% 3,989 3,989 1,651 1,651 5,640 5,640 SWL SWL Yield Yield BD BD Output Output Losses Losses BD BD Input Input RP RP Grade Grade

22 22

“ “As is As is” ” Yield Calculation Yield Calculation

21,000 21,000 Product Product 70.0% 70.0% 21,000 21,000 5,790 5,790 30,000 30,000 98.2% 98.2% 5,890 5,890 102 102 6,000 6,000 Broke Broke 51.4% 51.4% 3,084 3,084 131 131 6,000 6,000 Wetlap Wetlap 69.1% 69.1% 4,144 4,144 1,606 1,606 6,000 6,000 ONP ONP 59.9% 59.9% 3,592 3,592 2,299 2,299 6,000 6,000 CBK CBK 71.5% 71.5% 4,289 4,289 1,651 1,651 6,000 6,000 SWL SWL Yield Yield As is As is Output Output BD BD Losses Losses As is As is Input Input RP RP Grade Grade

23 23

Yield per RP Grade Yield per RP Grade

70.7% 59.2% 70.6% 95.6% 98.2% 77.1% 71.5% 69.1% 51.4% 98.2% 70.0% 59.9% 40% 50% 60% 70% 80% 90% 100% SWL CBK ONP Wetlap Broke Process YIELD.

BD As is

24 24

Calculate Furnish Cost to Headbox Calculate Furnish Cost to Headbox

• “

“As is As is” ” yield can be used to calculate yielded yield can be used to calculate yielded cost to the headbox cost to the headbox (if that RP grade was used 100%)

(if that RP grade was used 100%)

• Add RP cost + Freight + Mill storage & handling

Add RP cost + Freight + Mill storage & handling

• Divide by

Divide by “ “as is as is” ” yield = furnish cost / yield = furnish cost / “ “as is as is” ” ton ton

• Furnish cost

Furnish cost – – RP cost = shrink cost per ton RP cost = shrink cost per ton

• Example for SWL

Example for SWL (per

(per “ “as is as is” ” ton): ton):

• $270 + $20 freight + $10 S&H = $300

$270 + $20 freight + $10 S&H = $300

• Furnish cost = $300 / 71.5% = $416

Furnish cost = $300 / 71.5% = $416

• Shrink = $416

Shrink = $416 – – $300 = $116 $300 = $116

25 25

Allocate Residue Costs Allocate Residue Costs

• Monthly residue disposal costs can be

Monthly residue disposal costs can be allocated per RP grade: allocated per RP grade:

• Determine residue disposal cost per BD ton

Determine residue disposal cost per BD ton (incl. polymer costs, transport + disposal fee) (incl. polymer costs, transport + disposal fee)

• Add BD residue losses per grade

Add BD residue losses per grade

• Divide losses by

Divide losses by “ “as is as is” ” PM tons for each grade PM tons for each grade

• Example for CBK

Example for CBK (using hypothetical numbers)

(using hypothetical numbers):

:

• Disposal cost = $5,080,000 / (4,900 + 180) = $100

Disposal cost = $5,080,000 / (4,900 + 180) = $100

• Residue losses = (1,907 + 35) / 3,592 = 0.54

Residue losses = (1,907 + 35) / 3,592 = 0.54

• $100 x 0.54 BD tons residue / PM ton = $54

$100 x 0.54 BD tons residue / PM ton = $54

26 26

Allocate Bleach Costs Allocate Bleach Costs

• Determine bleach cost per

Determine bleach cost per “ “brightness brightness” ” ton ton

• Say monthly bleach costs = $360,000

Say monthly bleach costs = $360,000

• 21,000 PM tons x brightness increase = 120,000

21,000 PM tons x brightness increase = 120,000

• $360,000 / 120,000 brightness tons = $3

$360,000 / 120,000 brightness tons = $3

• Example for ONP:

Example for ONP:

• 4,144 PM tons x brightness increase = 100,000

4,144 PM tons x brightness increase = 100,000

• 100,000 brightness tons x $3 = $300,000

100,000 brightness tons x $3 = $300,000

• $300,000 / 4,144 PM tons = $72

$300,000 / 4,144 PM tons = $72

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Allocated Grade Cost Allocated Grade Cost to the Headbox to the Headbox

300 200 160 120 134 72 467 388 341

$0 $100 $200 $300 $400 $500 SWL CBK ONP

US$ / As is ton.

Allocated Costs Bleach Reject Disposal Yield Loss RP+Frt+S&H

56% 94% 113%

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Conclusion Conclusion

• By combining average lab data for each

By combining average lab data for each furnish component + monthly mill accounting furnish component + monthly mill accounting data in a spreadsheet, you can calculate yield data in a spreadsheet, you can calculate yield to the headbox for each RP grade. to the headbox for each RP grade.

• Convert the data to a BD basis.

Convert the data to a BD basis.

• Allocate furnish losses to appropriate RP grade.

Allocate furnish losses to appropriate RP grade.

• Calculate BD yield per RP grade

Calculate BD yield per RP grade

• Use this information to calculate the actual

Use this information to calculate the actual grade cost to the headbox. grade cost to the headbox.

29 29

Acknowledgment Acknowledgment

• The help of M. Doshi of Progress in Paper

The help of M. Doshi of Progress in Paper Recycling in reviewing the abstract + paper is Recycling in reviewing the abstract + paper is greatly appreciated. greatly appreciated.

• Questions?

Questions?