BENCHMARKING ENERGY USE IN CANADIAN PULP AND PAPER MILLS doc

These groups collect data on • purchased energy electricity, steam, fossil fuels • self-generated energy hog fuel, sludge, spent pulping liquor, hydroelectric power • sold energy electri

IN COLLABORATION WITH THEPULP ANDPAPERRESEARCH

INSTITUTE OF CANADA

BENCHMARKING ENERGY USE IN

For more information or to receive additional copies of this publication, contact

Canadian Industry Program for Energy Conservation

c/o Natural Resources Canada

580 Booth Street, 18th Floor

Ottawa ON K1A 0E4

Web site: www.paprican.ca

Library and Archives Canada Cataloguing in Publication

Benchmarking energy use in Canadian Pulp and Paper Mills

Text in English and French on inverted pages

Title on added t.p.: Analyse comparative de la consommation d'énergie dans le

secteur canadien des pâtes et papiers

ISBN 0-662-69589-5

Cat No M144-121/2006

1 Pulp mills – Energy consumption – Canada

2 Paper mills – Energy consumption – Canada

I Pulp and Paper Research Institute of Canada

II Canada Natural Resources Canada

III Title: Analyse comparative de la consommation d'énergie dans le secteur canadien despâtes et papiers

1 Photo courtesy of the Pulp and Paper Research Institute of Canada

2 Photo courtesy of Catalyst Paper Corporation

© Her Majesty the Queen in Right of Canada, 2008

Natural Resources Canada’s Office of Energy Efficiency

Leading Canadians to Energy Efficiency at Home, at Work and on the Road

TABLE OF CONTENTS

FOREWORD 1

1 INTRODUCTION 4

2 METHODOLOGY 8

3 RESULTS 14

4 DISCUSSION 28

5 INTERPRETATION OF THE RESULTS 34

5.1 How do the results affect my mill? 35

5.2 What steps do I take? 36

6 REFERENCES 40

APPENDICES 41

APPENDIX A AREA DEFINITIONS 42

APPENDIX B SAMPLE CALCULATION 50

APPENDIX C ENERGY BENCHMARKING SURVEY INSTRUCTIONS 56

DISCLAIMER

The information contained in Benchmarking Energy Use in Canadian Pulp and Paper Mills and the Energy

Benchmarking Survey Tool on the CD-ROM is intended to be used solely as an educational tool to help companies determine approximately how their facility compares against industry averages The information is not intended to replace the findings of a formal energy benchmarking study at a facility Under no circumstances will the

Government of Canada or the Pulp and Paper Research Institute of Canada (Paprican) be liable either directly or indirectly to any person who uses such information.

TMP for newsprint 17Figure 3-2 Fuel consumption for a kraft recausticizing area 18Figure 3-3 Thermal energy consumption of a kraft pulping area with a

continuous digester 19Figure 3-4 Thermal energy consumption of a kraft pulping area with a

batch digester 19Figure 3-5 Thermal energy consumption for a kraft pulp bleaching area for

softwood pulp 20Figure 3-6 Net thermal energy production for a mechanical pulping area

producing TMP for newsprint 21Figure 3-7 Thermal energy consumption for a paper machine area producing

newsprint 22Figure 3-8 Thermal energy consumption for a paper machine area producing

uncoated groundwood specialties 22Figure 4-1 Electricity consumption for manufacturing bleached kraft

market pulp 30Figure 4-2 Fuel consumption for manufacturing bleached kraft market pulp 30Figure 4-3 Thermal energy consumption for manufacturing bleached kraft

market pulp 31Figure 4-4 Electricity consumption for manufacturing newsprint from TMP 32Figure 4-5 Net thermal energy consumption for manufacturing newsprint

from TMP 32Figure B-1 Energy conversion and manufacturing areas of a mill producing

newsprint from TMP 50

List of Tables

Table 3-1 Distribution of mills by pulping process and product type 14

Table 3-2 Data quality 15

Table 3-3 Electricity consumption of pulp manufacturing areas 16

Table 3-4 Fuel consumption of pulp manufacturing areas 17

Table 3-5 Thermal energy consumption of pulp manufacturing areas 18

Table 3-6 Thermal energy production of pulp manufacturing areas 20

Table 3-7 Electricity consumption of product manufacturing areas 21

Table 3-8 Fuel consumption of product manufacturing areas 22

Table 3-9 Thermal energy consumption of product manufacturing areas 23

Table 3-10 Electricity consumption of common areas 23

Table 3-11 Fuel consumption of common areas 23

Table 3-12 Thermal energy consumption of common areas 24

Table 3-13 Electricity consumption of boiler areas 24

Table 3-14 Fuel consumption of boiler areas 24

Table 3-15 Thermal energy consumption of boiler areas 25

Table 3-16 Electricity consumption of kraft recovery boilers 25

Table 3-17 Fuel consumption of kraft recovery boilers 25

Table 3-18 Net thermal energy production of kraft recovery boilers 25

Table 3-19 Thermal energy consumption of generators 26

Table 3-20 Steam consumption of deaerators 26

Table 4-1 Energy consumption and production for unbleached kraft pulp 28

Table 4-2 Energy consumption and production for bleached kraft pulp 29

Table 4-3 Energy consumption and production for manufacturing bleached kraft market pulp 29

Table 4-4 Energy consumption and production for manufacturing newsprint 31

Table A-1 Technology descriptors–pulp manufacturing areas 42

Table A-2 Technology descriptors–product manufacturing areas 45

Table A-3 Technology descriptors–common areas 47

Table A-4 Technology descriptors–energy conversion areas 48

Table B-1 Energy data for a newsprint mill 52

Table B-2 Reconciled energy data for a newsprint mill 53

Table B-3 Specific energy data for a newsprint mill 55

Table B-4 Energy consumption of the power boiler 55

1 FOREWORD

The Canadian pulp and paper sector, founded 200 years ago, has become an important

component of the Canadian economy Pulp and paper manufacturing is highly integrated

with its allied sectors in the forest products industry—forestry and wood products

The forest products industry contributes 3 percent of Canada’s gross domestic product

The industry operates in communities throughout Canada, providing direct employment

for 360 000 Canadians

The pulp and paper sector is one of the most energy-intensive sectors, consuming

approximately 30 percent of the industrial energy used in Canada Because energy is a

significant production-cost component (about 25 percent), the sector has made efforts to

reduce its fuel costs by switching to renewable biomass sources (by-products of the

production process) and energy efficiency improvements

Pulp and paper manufacturing is unique among manufacturing sectors in that it sources

57 percent of its energy consumption from biomass As well, the sector reduced its energy

use by an average of 1 percent annually since 1990 through improvements in energy

efficiency These achievements have been well documented by the industry and through

initiatives such as the Canadian Industry Program for Energy Conservation (CIPEC)

Although its progress on energy conservation is impressive, the pulp and paper sector wants

and needs to go further The sector aims to produce all the energy it requires, to ensure its

long-term competitiveness in the global market In fact, the industry has the potential to

become a net exporter of energy It has the largest industrial cogeneration capacity in

Canada and has the potential for further installations

How can the industry become more energy efficient? It must implement both proven and

new technology However, mills must understand how they use energy before they adopt

new energy sources or technology

That is where energy benchmarking can help This benchmarking study, conducted by the

Pulp and Paper Research Institute of Canada (Paprican), shows how the sector uses energy

The study found causes of wasted energy, but also revealed that sector best practices are

near the theoretical minimums for certain process segments

Its results will help Canada’s pulp and paper manufacturers adopt today’s best practices

more consistently across the sector while investigating the best practices of tomorrow

1

Governments and pulp and paper trade associations, such as the Forest Products

Association of Canada (FPAC), collect data about energy use and about pulp and paperproduction for economic policy and planning See Figure 1-1

These groups collect data on

• purchased energy (electricity, steam, fossil fuels)

• self-generated energy (hog fuel, sludge, spent pulping liquor, hydroelectric power)

• sold energy (electricity, steam)

• pulp and paper production

These data can be used to calculate the energy intensity of a mill, by dividing the mill’senergy consumption by its pulp and paper production

The energy intensity can be used for global benchmarking even when you do not knowspecifics about the products and manufacturing processes.1Global benchmarking makes aninitial assessment of where the mill’s operations rank in the industry However, this

benchmarking can identify only the potential for energy savings, not where they can beachieved

Figure 1-1 Energy inputs and outputs of a pulp and paper mill

To identify where process improvements and energy savings can be achieved, benchmarking

comparisons should be made for individual process areas in the mill

For example, in a thermomechanical pulp (TMP) newsprint mill, the total steam demand is

determined by the performance of both the TMP reboiler and the paper machine dryer

High steam consumption can result from poor performance of the reboiler or the dryer,

and a global benchmarking survey cannot determine which area requires improvement

However, by comparing these two individual process areas you can determine which area

requires improvement

In this report, the Pulp and Paper Research Institute of Canada (Paprican) describes a

method for benchmarking the energy use for process areas in pulp and paper mills

Paprican then presents the results of a benchmarking survey of energy use in Canadian pulp

and paper operations

In “Methodology,” the benchmarking method is explained Energy use in pulp and paper

mills was analysed by examining energy conversion areas and manufacturing areas

In “Results,” the results of the detailed data analysis in manufacturing areas and energy

conversion areas from 49 mills are presented

In “Discussion,” the energy consumption to produce two product grades, kraft pulp and

newsprint, from TMP is determined by combining the relevant manufacturing areas at mill

sites

In “Interpretation of the Results,” reasons are given for why the results for each area

benchmarked may differ

“How do the results affect my mill?” presents information about how to use the results

from the benchmarking study

“What steps do I take?” provides a seven-step process explaining how you can start to find

opportunities for energy efficiency improvements

“Appendix A Area definitions” lists the definitions for the process areas in the pulp and

paper mill

Sample calculations are described in “Appendix B Sample calculation.”

“Appendix C Energy benchmarking survey instructions” concludes the report with

instructions on how to benchmark your facility using the enclosed CD-ROM, which

includes an Excel workbook The workbook contains spreadsheets (six visible and one

hidden) with step-by-step instructions The information is not intended to replace the

findings of a formal energy benchmarking study at a facility

2

Data are collected on

• purchased energy

• self-generated energy

• sold energy

• pulp and paper production

With this information, you can make global benchmarking comparisons for mill operations.The energy and fibre resources are allocated to areas This allows benchmarking

comparisons for individual areas in a mill and for product grades

The benchmarking method has four steps:

• establish process areas

• collect data

• allocate and reconcile data

• calculate energy consumption

Establish process areas

The first step is to divide the pulp and paper mill into process areas The areas are described

in Appendix A

Figure 2-1 shows the process areas of a mill that produce newsprint and kraft market pulpfrom TMP and kraft pulp

There are two kinds of process areas: energy conversion areas and pulp and paper

manufacturing areas In the energy conversion areas, purchased and self-generated energyare converted to steam and electricity for use in the manufacturing areas or for sale Theenergy conversion areas include power and recovery boilers, a backpressure turbine and adeaerator

In the manufacturing areas of pulp and paper manufacturing operations, energy resources(fuel, steam and electricity) and fibre resources are used to produce newsprint and kraftmarket pulp

• general areas (for example, buildings)

Figure 2-1 Energy conversion areas and manufacturing areas of the pulp and paper mill

Kraft Recovery Boiler

Deaerator

Back Pressure Turbine

Manufacturing Areas

Mechanical Pulping TMP 1

Wood Preparation

Mechanical Pulping TMP 2 Mechanical

Pulping TMP 3

Kraft Pulping

Kraft Bleaching

Kraft Recaust.

Paper Machine

Kraft Evaporators

Effluent Treatment

General Buildings

Pulp Machine

Each of the energy conversion and manufacturing areas is defined by its product

For example, the mechanical pulping area in Figure 2.2 produces TMP from electricity andchips The input boundary is the inlet of the chip bin; the output boundary is the pulpstorage tank after thickening

The mechanical pulping area includes

Chips

Boiler Feed Water Steam

Mechanical Pulp

In Figure 2-2, the energy intensity of the process area is the energy consumption divided

by the pulp production The energy intensity is calculated by using the reconciled data Foreach energy conversion and manufacturing area, technology descriptors are defined toaccount for different energy use by different technologies For example, in mechanicalpulping, the energy use varies relative to the pulping process and the heat recovery

The pulping process descriptors for mechanical pulping are

The heat recovery descriptors are

• primary refiners only

• mainline refiners only

• mainline and reject refiners

• none

These technology descriptors allow you to make benchmarking comparisons among areas

with the same technology (for example, TMP lines) or between areas with different

technologies (for example, between SGW lines and TMP lines) Similar technology

descriptors are defined for the other energy conversion and manufacturing areas See

Appendix A

Collect data

The second step is to collect data on energy inputs and outputs for the mill and for pulp

and paper production This is the same information that is collected in global

benchmarking studies

For the mill in Figure 2-1, the energy inputs can include fuel (purchased fossil fuel,

self-generated spent pulping liquor), electricity and steam The energy outputs can include

electricity and steam

Data are also collected on condensate input and output because the thermal energy input

to the mill is the steam input (for example, from a cogeneration plant) minus the

condensate returned to the steam supplier

At most mills, engineers from Paprican visited the mill site for several days to collect the

energy and production data from mill staff and mill information systems This practice

ensures a consistent method for the allocation of energy and fibre resources to the energy

conversion and manufacturing areas However, for a few mills, the mill staff, in consultation

with a Paprican engineer, recorded the data

At all mills, the data were recorded in a spreadsheet tool to facilitate data checking and data

reconciliation Paprican collected data from 51 mills: 49 mills in Canada and 2 mills in the

United States that were similar to the Canadian operations of the same companies These

mills represent 55 percent of Canadian production capacity and provided data for the

major pulping processes and product grades of the Canadian pulp and paper industry

Allocate and reconcile data

The third step is to allocate the energy and fibre resources to the energy conversion and

manufacturing areas For each area, data are collected on energy inputs and outputs and on

fibre inputs and outputs

For the mechanical pulping area in Figure 2-2, the energy inputs are electricity and the feedwater to the reboiler; the energy output is the reboiler steam The fibre input is chips fromwood preparation; the fibre output is TMP

Ideally, all the energy inputs to the mill would be allocated to areas in the mill and to anyenergy sales That is, energy inputs and outputs would balance Realistically, there will not

be a perfect energy balance because of instrument measurement errors and estimationswhen measurements are unavailable

The quality of the data is recorded when the energy and fibre data are collected:

• A–reliable instrumentation with good calibration

• B–less reliable instrumentation

• C–calculated by heat and material balance from measured values

• D–estimated when measurements are unavailable

This information is used to weight the corrections needed to reconcile the energy and fibredata

Calculate energy consumption

The fourth step is to calculate the specific energy consumption for each area from its

energy consumption and fibre production, by using the reconciled data These results allowthe mill staff to identify where their operations are least efficient and thereby to identifyareas that require changes in operating procedures or capital investments A sample

calculation for a newsprint mill is shown in Appendix B

3

3 RESULTS

The Pulp and Paper Research Institute of Canada (Paprican) collected energy and

production data from 51 mills on a quarterly basis For most mills, Paprican collected datafor four consecutive quarters For two mills, Paprican could collect data for only onequarter The data for these two mills were excluded from the analysis, leaving 49 mills inthe data set This section presents the results of the energy benchmarking survey for themanufacturing and energy conversion areas of the 49 pulp and paper mills

Data analysis

Table 3-1 shows the distribution of mills by pulping process and product type for the

49 pulp and paper mills Several mills had multiple pulping processes and multiple producttypes

Table 3-1 Distribution of mills by pulping process and product type

Total Mills in Data Analysis

Mills by Pulping Process

Mechanical Pulping Kraft Pulping Recycled Pulping Sulphite Pulping

Mills by Product Type

Pulp Newsprint Paper (other than newsprint) Board

49

28 24 10 4

27 20 17 5

The difference between the energy inputs (purchased and produced) and energy outputs(consumed and sold) for a mill indicates how well the energy was allocated to the energyconversion and manufacturing areas

The average and 90th percentile values for the difference between energy inputs andenergy outputs are shown in Table 3-2 The largest differences were for steam and

condensate

There were problems in allocating the electricity to the areas The power distribution and

metering were not arranged by area in some cases Therefore, the total electricity

consumption was correct but the allocation to individual areas was not accurate for some

mills

For example, some of the power for the kraft evaporators area were measured in the kraft

recovery boiler area Therefore, the measurements of the electricity consumption for the

kraft evaporators are lower than the actual value, and the measured consumption for the

kraft recovery boiler is higher than the actual value However, the power was measured

accurately in areas such as mechanical pulping and turbogenerators, where there was

significant electricity consumption or production

Manufacturing areas

The energy consumption and production of the manufacturing areas are shown in Tables

3-3 to 3-12 The tables show the 25th percentile, median and 75th percentile specific

energies for each area.*

For most areas, the fibre allocated to the area was equal to the fibre produced by the area

For kraft evaporators and recausticizing, the fibre allocation was the unbleached kraft pulp

produced in the kraft pulping area

For the sulphite acid plant, the fibre allocation was the unbleached sulphite pulp produced

in the sulphite pulping area

For the common areas, the fibre allocated was the total mill production

The tables also show the energy values (adapted from recent literature)4, 5 for the

manufacturing areas that use modern technology

Table 3-2 Data quality

Electricity Fuel Steam Condensate

Energy Inputs – Energy Outputs (%) †

* The k percentile is the value of a distribution with k percentage of the values equal to or below it Thus, the 25th percentile value is equal to or greater than 25

percent of the values of the distribution; the median (50th percentile) value is equal to or greater than 50 percent of the values; the 75th percentile value is equal

to or greater than 75 percent of the values.

Harrison Hot Springs, British Columbia, May 7–10, 2003.

Be careful when making direct comparisons of the energy data in this report with reports

of best practices The data for best practices are derived from several sources, and thosesources can draw area boundaries in different ways, or they may apply only to specifictechnologies

In addition, the definition of thermal energy (the steam consumed minus the condensatereturned to the boiler) may not be the same in various reports Consequently, use thesecomparisons with best practices as general guides only

16

Table 3-3 Electricity consumption of pulp manufacturing areas

25th Percentile Median 75th Percentile Modern

Kraft Pulping – Continuous 150.50 179.50 221.30 161.00 Kraft Pulping – Batch 134.90 169.30 230.50 161.00 Kraft Pulping – M&D 166.00 190.90 208.70 NA Kraft Evaporators – Indirect Contact 0.00 15.70 30.60 33.00 Kraft Evaporators – Direct Contact 10.00 24.50 44.70 NA

Kraft Bleaching – Softwood 112.30 179.50 240.70 122.00 Kraft Bleaching – Hardwood 117.10 143.90 237.50 NA

Mechanical Pulping – TMP for Newsprint 2508.60 2661.60 2786.80 2450.00 to 2600.00 Mechanical Pulping – TMP for Paper 2586.60 2943.20 3261.10 2650.00 to 2800.00 Mechanical Pulping – SGW 1690.80 1780.30 2081.70 1500.00 to 1800.00 Mechanical Peroxide Bleaching 84.10 133.80 232.50 NA

Electricity Consumption (kWh/ODt) †

mechanical pulping – TMP for paper include uncoated groundwood specialties and printing and writing paper; some of the pulp may also be used for newsprint.

The energy consumption and production of various manufacturing areas are shown inFigures 3-1 to 3-8 The mills that followed best practices used the least energy Thevariations in energy consumption for each area indicate the realistic potential for energyreductions

The mechanical pulping areas in pulp manufacturing used the most energy The

distribution of electricity consumption for the mechanical pulping area producing TMP for

newsprint is shown in Figure 3-1 The lowest electricity consumption value is suspect The

variation of the remaining values is related to wood species primarily, not to operating

practices

The largest fuel consumption for pulp manufacturing occurred in the kraft recausticizing

area The fuel is used in the lime kiln The distribution of fuel consumption for the kraft

recausticizing area is shown in Figure 3-2

Figure 3-1 Electricity consumption for a mechanical pulping area producing TMP for newsprint

Table 3-4 Fuel consumption of pulp manufacturing areas

25th Percentile Median 75th Percentile Modern

Fuel Consumption (GJ/ODt) †

Annual Value Range of Quarterly Values

4 3.5 3 2.5 2 1.5 1 0.5 0

Figure 3-2 Fuel consumption for a kraft recausticizing area

Table 3-5 Thermal energy consumption of pulp manufacturing areas

25th Percentile Median 75th Percentile Modern

Kraft Evaporators – Indirect Contact 5.03 5.91 7.06 3.20 Kraft Evaporators – Direct Contact 2.90 2.96 3.89 NA

Sulphite Pulping 4.11 5.00 6.48 NA Sulphite Acid Plant 0.00 – – NA

Mechanical Pulping – TMP for Newsprint 0.39 0.56 0.80 0.00 Mechanical Pulping – TMP for Paper 0.03 0.67 0.93 0.00

Mechanical Peroxide Bleaching 0.00 0.00 0.13 0.00

Thermal Energy Consumption (GJ/ODt) †

Annual Value Range of Quarterly Values

Thermal energy consumption for some kraft pulp manufacturing areas are shown in Figures

3-3 to 3-5 Although the median value for kraft pulping with a continuous digester (Figure

3-3) is lower than that for pulping with a batch digester (Figure 3-4), some batch digester

areas consume less thermal energy than some continuous digester areas This fact indicates

that both technology and operating practices affect the energy consumption

Figure 3-4 Thermal energy consumption of a kraft pulping area with a batch digester

Annual Value Range of Quarterly Values

Annual Value Range of Quarterly Values

Thermomechanical pulping produces a large amount of thermal energy that can be

recovered with a reboiler as clean steam The net thermal energy production for the area isthe thermal energy of the steam production less the thermal energy consumption

The net thermal energy production for mechanical pulping areas that produce TMP fornewsprint is shown in Figure 3-6 Negative values represent net thermal energy

consumption Seventeen of the 36 TMP lines recover thermal energy to produce steam

20

10 9 8 7 6 5 4 3 2 1 0

Figure 3-5 Thermal energy consumption for a kraft pulp bleaching area for softwood pulp

Table 3-6 Thermal energy production of pulp manufacturing areas

25th Percentile Median 75th Percentile Modern

Mechanical Pulping – TMP for Newsprint 0.00 0.00 3.50 5.00 to 5.50 Mechanical Pulping – TMP for Paper 0.00 0.00 1.04 5.50 to 6.00

Thermal Energy Production (GJ/ODt) †

Annual Value Range of Quarterly Values

Thermal energy consumption for various product manufacturing areas are shown in Figures

3-7 and 3-8 Although the median value for paper machine areas that produce newsprint

(Figure 3-7) is lower than that for uncoated groundwood specialties (Figure 3-8), some

paper machine areas that produce uncoated ground wood specialties consume less thermal

energy than some areas that produce newsprint

Table 3-7 Electricity consumption of product manufacturing areas

25th Percentile Median 75th Percentile Modern

Paper Machine – Newsprint 502.90 565.20 622.40 330.00

Paper Machine – Uncoated Ground wood 559.10 677.00 777.10 NA

Paper Machine – Printing and Writing 595.80 662.50 706.70 550.00

Paper Machine – Kraft Papers 823.90 1021.50 1108.80 NA

Pulp Machine – Steam Dryer 119.10 153.20 191.30 141.00

Electricity Consumption (kWh/ADt) †

Annual Value Range of Quarterly Values

18 16 14 12 10 8 6 4 2 0

Table 3-8 Fuel consumption of product manufacturing areas

25th Percentile Median 75th Percentile Modern

Fuel Consumption (GJ/ADt) †

Annual Value Range of Quarterly Values

Annual Value Range of Quarterly Values

Table 3-9 Thermal energy consumption of product manufacturing areas

25th Percentile Median 75th Percentile Modern

Paper Machine – Uncoated Groundwood 4.93 6.21 7.01 NA

Paper Machine – Printing and Writing 5.74 6.32 8.31 5.10

Thermal Energy Consumption (GJ/ADt) †

Table 3-10 Electricity consumption of common areas

25th Percentile Median 75th Percentile Modern

Effluent Treatment – Activated Sludge 31.80 49.40 80.60 30.00

Effluent Treatment – Aerated Lagoon 34.30 47.60 70.80 30.00

Electricity Consumption (kWh/ADt) †

Table 3-11 Fuel consumption of common areas

25th Percentile Median 75th Percentile Modern

Fuel Consumption (GJ/ADt) †

Energy conversion areas

The energy consumption and production of the energy conversion areas are shown inTables 3-13 to 3-20 The tables show the 25th percentile, median and 75th percentilespecific energy consumption for each area The tables also show the energy values adaptedfrom recent literature6, 7for the manufacturing areas that use modern technology

In Tables 3-13 to 3-15, the energy consumption is expressed in terms of thermal energyproduced by the boilers The thermal energy production is equal to the steam producedminus the condensate (boiler feed water) consumed

24

Table 3-12 Thermal energy consumption of common areas

25th Percentile Median 75th Percentile Modern

Effluent Treatment – Activated Sludge 0.00 0.00 0.00 NA Effluent Treatment – Aerated Lagoon 0.00 0.00 0.17 NA

Thermal Energy Consumption (GJ/ADt) †

Table 3-13 Electricity consumption of boiler areas

25th Percentile Median 75th Percentile Modern

Kraft Recovery Boiler – Low Odour 3.10 5.20 7.20 4.00 Kraft Recovery Boiler – Direct Contact 4.80 9.00 10.90 NA

Electricity Consumption (kWh/GJ) †

Table 3-14 Fuel consumption of boiler areas

25th Percentile Median 75th Percentile Modern

In Tables 3-16 to 3-18, the energy consumption and net thermal energy production are

expressed in terms of unbleached kraft pulp produced in the kraft pulping area The net

thermal energy is the thermal energy produced by the recovery boiler minus the thermal

energy used by the recovery boiler (for example, for soot blowing)

Table 3-15 Thermal energy consumption of boiler areas

25th Percentile Median 75th Percentile Modern

Kraft Recovery Boiler – Low Odour 0.11 0.14 0.19 0.05

Kraft Recovery Boiler – Direct Contact 0.14 0.16 0.17 NA

Thermal Energy Consumption (GJ/GJ) †

Table 3-16 Electricity consumption of kraft recovery boilers

25th Percentile Median 75th Percentile Modern

Kraft Recovery Boiler – Low Odour 54.60 82.60 112.00 70.00

Kraft Recovery Boiler – Direct Contact 73.50 100.60 133.40 NA

Electricity Consumption (kWh/ODt) †

Table 3-17 Fuel consumption of kraft recovery boilers

25th Percentile Median 75th Percentile Modern

Kraft Recovery Boiler – Low Odour 26.16 28.78 29.61 NA

Kraft Recovery Boiler – Direct Contact 22.34 26.39 30.79 NA

Fuel Consumption (GJ/ODt) †

Table 3-18 Net thermal energy production of kraft recovery boilers

25th Percentile Median 75th Percentile Modern

Kraft Recovery Boiler – Low Odour 13.45 14.63 16.72 NA

Kraft Recovery Boiler – Direct Contact 9.66 10.58 11.84 NA

Net Thermal Energy Production (GJ/ODt) †

blowing The specific energy is the net thermal energy produced divided by the fibre allocated to area expressed on an oven-dried basis.

The thermal energy consumption for power generation is expressed in terms of the

electricity generated See Table 3-19 The specific energy is the thermal energy consumeddivided by the electricity generated

26

Table 3-19 Thermal energy consumption of generators

25th Percentile Median 75th Percentile Modern

Back-Pressure Turbine – Electricity 3.71 3.77 4.36 3.70 Condensing Turbine – Electricity 8.68 9.74 14.14 8.60

Thermal Energy Consumption (MJ/kWh) †

Table 3-20 Steam consumption of deaerators

25th Percentile Median 75th Percentile Modern

Steam Consumption (%) †

percent condensate return for the mill.

The deaerator produces boiler feed water from condensate, make-up water and steam Thenet thermal energy produced for the deaerator does not provide useful information because

it is equal to the enthalpy of the water make-up minus any heat losses

Instead of reporting the specific thermal energy produced for the deaerator, Papricancalculated the steam consumption at the deaerator at each mill as a percentage of the totalsteam production See Table 3-20

4