Paper recycling environmental and economic impact

E L S E V I E R Resources, Conservation and Recycling 21 1997 109-127 ~ t l ~ a and Paper recycling: environmental and economic impact Stig Bystr6m a Lars L6nnstedt b,, a MoDo Pulp

E L S E V I E R Resources, Conservation and Recycling 21 (1997) 109-127

~ t l ~ a

and

Paper recycling: environmental and economic

impact Stig Bystr6m a Lars L6nnstedt b,,

a MoDo Pulp and Paper, S-891 01 Ornsk6ldsvik, Sweden and the Department of Forest-Industry-Market Studies, the Swedish University of Agricultural Sciences, Box 7054, S-750 07 Uppsala, Sweden

b The Department of Forestry Economics, the Swedish University of Agricultural Sciences,

S-901 83 Umegt, Sweden

Received 27 June 1996; received in revised form 28 May 1997; accepted 23 June 1997

Abstract

The Optimal Fibre Flow Model, a combined optimization and simulation model, calcu-

lates the optimal combination of energy recovery and recycling of waste paper for paper and

board production In addition, the environmental impact is estimated by using an environ-

ment load unit-index (ELU-index) The ELU-index assigns an environmental load value to

emissions and to the use of non-renewable resources such as oil and coal Given a 'forced'

utilization rate for the Scandinavian forest industry, optimization of marginal revenue shows

environmental impact to be at a minimum with a utilization rate of about 30% in

Scandinavia and 73% (an assumed upper limit) for the rest of Europe If instead environmen-

tal impact is minimized, the utilization rate for Scandinavia is almost the same, while the

utilization rate for the rest of Europe is 53% (a lower assumed level) Given a fixed use of

virgin fibres for the rest of Western Europe, a comparison of the environmental load at

different 'forced' utilization rates for the Scandinavian forest industry shows no significant

differences between the economic and environmental optimizations © 1997 Elsevier Science

B.V

Keywords: Systems analysis; Model; Policy analysis; Life cycle analysis; Waste paper; Energy

* Corresponding author Tel.: + 46 90 7866032; fax: + 46 90 7866073

0921-3449/97/$17.00 © 1997 Elsevier Science B.V All rights reserved

PII S0921-3449(97)00031- 1

110 S Bystr6m, L L6nnstedt / Resources, Conservation and Recycling 21 (1997) 109-127

I Introduction

A key issue in paper recycling is the impact of energy use in manufacturing Processing waste paper for paper and board manufacture requires energy that is usually derived from fossil fuels, such as oil and coal In contrast to the production

of virgin fibre-based chemical pulp, waste paper processing does not yield a thermal surplus and thus thermal energy must be supplied to dry the paper web If, however, the waste paper was recovered for energy purposes the need for fossil fuel would be reduced and this reduction would have a favourable impact on the carbon dioxide balance and the greenhouse effect Moreover, pulp production based on virgin fibres requires consumption of roundwood and causes emissions o f air-pol- luting compounds as does the collection of waste paper

The forest industry has become a convenient target for the environmental ambitions of consumers and politicians In countries like Germany, Sweden and the

US this has led to demands for changes in the industrial forest production system The forest industry o f the Scandinavian countries fear that political decisions made

by the European Union, or individual countries will force a fixed utilization rate for waste paper in paper and board production The risk is that such decisions will lead

to sub-optimal use of waste paper, if the environmental impacts o f alternative uses are not fully considered Important alternatives other than recycling for production

o f paper are energy recovery and landfill Fig 1 gives a principle outline o f linkages

o f the fibre flow when Western Europe is divided into two regions [1]

The benefits o f paper recycling have not been fully analyzed [22], though increased recycling is generally assumed to be desirable and necessary Waste management policy in a number of countries is characterized by a hierarchy of options in which waste minimization, reuse and recycling are all considered preferable to energy recovery This is in turn considered superior to landfill

Scandinavia

CO2 (

Energy

I re]very

t

ConsumlXion Products and Waste paper

consumption

Rest of Western Europe

I

Energy

a re]very

Fig 1 Principle flow of fibres in Western Europe

S Bystr6m, L L6nnstedt / Resources, Conservation and Recycling 21 (1997) 109-127 111

However, any assessment of recycling should compare the impacts, costs and benefits of recycling with those of alternative options for waste disposal This is the main purpose of this paper

2 Approach

2.1 Literature reviewed

Examples of early economic studies of the supply and demand or trade, with waste paper are Grace et al [2] and Yohne [3] They examined international trade and its importance to price Price expectations and the effect of price changes have been analyzed by Edwards [4], Deadman and Turner [5] and Kinkley and Lahiri [6] Gill and Lahiri [7] and Edgren and Moreland [8] found low price elasticities for waste paper, which indicates that price subsidies are not recommended for stimulat- ing use In a Swedish study of the printing industry, Rehn [9] shows that the uses

of pulp, pulp wood and waste paper are sensitive to their individual price changes with substitution likely

More recently, systems analysis and extensive modelling approaches have been used for studying the waste paper problem Colletti and Boungiorno [10] and the NAPAP model [11] concentrate on production and economic aspects of waste paper recycling Virtanen and Nilsson [12] incorporate environmental aspects of recycling into their study

A comprehensive review of existing information on the paper cycle from forestry through to recycling, energy recovery, and waste paper disposal has been prepared

by The International Institute for Environment and Development [13] It is worth noting that consultancy companies have also done some interesting analyses Examples include Virta [14] and FAO [15] which give, respectively, valuable data and an analysis of the consequences of increased recycling in four different countries

2.2 A i m and methodology

In this paper, an interactive model, the Optimal Fibre Flow Model, considers both a quality (age) and an environmental measure of waste paper recycling Characteristics of the model are a simultaneous treatment of the following sectors:

• Energy and fibre

• Environment

• Quality (fibre age and fibre type distributions)

The system limits are straight forward, i.e most of the fibre production and fibre use in Western Europe are included Put simply, the following question is addressed

by the model:

• What are the environmental impacts of different recovery requirements? The dynamics and development of the fibre cycle are analyzed using a combined optimization and simulation model An engineering approach is taken to describe

112 S Bystr6m, L Ldnnstedt / Resources, Conservation and Recycling 21 (1997) 109-127

the production processes However, both economic and environmental aspects are considered The Model generates optimal flows of fibres under various assumptions Consideration of the effect of all relevant processes and transports on the environ- ment are included in the Model; for example, the carbon dioxide balance is calculated in the system Thus, the Model not only includes calculations of the industry-related fibre cycles but also the role of forestry and forest products in the climatologically important circulation of carbon dioxide The environmental effects

of the different activities in the total system are also added using the same methodology as used in some life cycle analyses, are Individual emissions and each use of non-renewable resources, such as oil and coal, are given an environmental load index value (ELU-index) The ELU-index is developed from a system for Environmental Priority Strategies in Product Design, the so called EPS-system [16] The system is based on the willingness to pay to avoid the consequences of different emissions We register all production processes and emissions instead of as in the established methodology of life cycle analysis concentrating on usually only paper and board production

3 Model

3.1 Structure

Western Europe is divided into two regions, Scandinavia (Finland, Norway and Sweden) and Continental Western Europe and the UK (Compare Fig 1) Some- times Scandinavia is described as the 'lumberyard' of the other region Each region has production resources and a market for paper products and energy The products produced are delivered either to the domestic market or to the export market After end-use, paper is recycled for production of paper and board and/or recovered for energy use If recycled, the waste paper is recovered, sorted, baled and transported to paper mills in either of the regions for production of recycled pulp

If recovered for energy use, the waste paper is assumed to follow the normal waste-handling system It then replaces oil or coal Eventually, the collected paper

is exported to Scandinavia or the rest of Western Europe The production value of waste paper depends on the price of fossil fuel and round timber The higher the price of oil, the more waste paper is recovered for energy purposes Waste paper which is not reused has no economic value and a negative environmental value in the Model Thus, in the Model all waste paper is recovered It is assumed that enough capacity exists for de-inking and energy production

Twelve different paper qualities are produced in the Model: newsprint, SC paper, LWC, office paper (wood-free), coated paper (wood-free), tissue, white lined chipboard, 'return fibre chipboard', wrapping paper, white liner, kraft-liner and fluting Recipes specifying the need for fibres, filler and energy are given for each product The Model chooses between virgin fibres and recycled fibres in keeping with the quality expected of the products Five different flush pulps and market pulps are included Dried pulp in sheets is delivered from Scandinavian producers

s Bystr6m, L L6nnstedt /Resources, Conservation and Recycling 21 (1997) 109-127 113

to non-integrated paper mills in other parts of Western Europe The need for pulp wood (short and long fibres) and energy is specified for each of the pulp qualities Surplus energy from pulp processing is used in the paper production Electricity can

be produced from back-pressure power or in condensation power stations that burn coal, oil, wood or waste paper However, the major source of electricity in the Nordic countries is hydroelectric power plants

Costs connected to the different processes are considered The age distribution of the fibres in each product is calculated ([17]; also compare [18]) The model includes the yields in different processes, and these can be made age-dependent Further- more, the energy needs for production of chemicals are included Different types of emissions to the atmosphere and water, except those from plants producing chemicals for the pulp mills, are calculated and later converted into comparative environmental indexes Below, we describe the different subsystems that make up the Model

The Forestry part of the Model describes how the forest absorbs carbon dioxide Timber harvest and transport cause energy consumption and costs Energy used in producing fertilizers is also considered

The pulp mill module describes the production of pulp using wood as the raw material Apart from wood, use is made of electricity, thermal energy and chemi- cals Excess energy in the pulp mill can be used in the paper mill Electricity can be produced by back-pressure steam turbines or by condensing turbines

In the de-inking mill module, waste paper pulp is produced from recovered paper The Model calculates the consequences of poor quality waste paper material

In other respects, the calculations are the same as for the pulp mill Both the yield

of the process that produces recycled pulp and the energy value in waste paper are calculated on the basis of the fibre composition of each individual product In addition, the effect of filler is considered The efficiency in the recycled pulp mill and the thermal energy recovered from burning paper are dependent on the composition of the paper

The paper mill module of the Model describes how paper is produced from virgin pulp and waste paper pulp In addition, use is made of different types of energy and fillers Emissions to the atmosphere and to the water are registered The paper products can be produced with different amounts of recovered paper from different products Restrictions in the Model prohibit, however, incorrect combinations Wood-containing paper is not used, for example, when making wood-free qualities

In the Model, collection of waste paper requires energy in the form of diesel fuel, electricity and other resources represented by variable costs Standard emissions to the environment are considered The need for resources varies depending on both the product and region The resources needed (energy and financial) to collect paper are progressive For example, depending on quality, the resources needed to collect the last 30% of the consumption are three to six times higher then those needed to collect the first 30% It is assumed that sufficient industrial capacity exists to recover waste paper as fibres or as energy This implies that the recovered waste paper does not end up as landfill, even if this is an option, because it has economic value for both paper and energy production

114 S Bystr6m, L L6nnstedt / Resources, Conservation and Recycling 21 (1997) 109-127

All processes, including transport, require energy All energy in the Model is generated in an energy plant where emissions to the environment are also calcu- lated Energy can be purchased but some forms o f energy cannot be substituted, e.g all transport based on diesel fuel Electricity and heat, on the other hand, can

be generated both by fossil fuel (oil or coal) and by combustion o f fibre products

In Scandinavia, electricity can be produced from water and fossil fuels, whereas the rest o f Western Europe must rely on electricity generated by fossil fuels Naturally, emissions are affected

The mathematical expressions o f the Model are described in Appendix A

3.2 Environmental load unit index

To calculate the environmental impact of pulp and paper production, the use o f non-renewable resources and effects of emissions are added together In the Model, this is done using an environment load unit-index (ELU-index where 1 E L U corresponds to 1 ECU) based on the Environmental Priority Strategies in Product Design (EPS) method [16] This evaluation method was developed in 1991 and revised in 1994 by the Swedish Environmental Research Institute (IVL) with the Swedish Federation of Industries and the Volvo Car Corporation It is used in the realm of LCA to assess the environmental burden o f many products or processes According to this criterion, each impact is evaluated as costs and quantified in ELU Two different indices are calculated for resources and emissions In the case

o f resources:

where A is worldwide per capita of finite natural resources, B is an estimated irreplaceability factor, and C is a scale factor to match the emission indices In the case of emissions:

where F~ represents the environmental and health cost o f the problem as it is seen

by society, F2.3.4 describe the extent o f the problem in a term of frequency, durability and geographical distribution, F5 correlates the amount of the specific emission to the selected problem, and F6 is a measure o f the cost of an immediate action to solve the problem, i.e the use o f an emission control system

This model aims to build a simple pressure indicator by aggregating many independent factors, thus giving any future user the possibility o f modifying and adapting the index to specific cases Its methodological framework is both concep- tually valid and well structured Nonetheless, the sheer number o f different coeffi- cients which occur in the indicator expression can be difficult to calculate However,

o f the methodologies available for evaluation purposes, the EPS has good charac- teristics for warranting its inclusion in comparative economic-environmental analy- sis

F o r example, the 'value' o f the use o f 1 kg o f fresh water in areas with a water deficiency is 0.003 ELU As can be seen in Table 1, the 'punishment' for destroying

S Bystr6m, L L6nnstedt / Resources, Conservation and Recycling 21 (1997) 109-127

Table 1

ELU-index used in the Model

115

Non-renewable resources

Emmisions

1 m 3 of oil is 360 ELU The ELU-index for non-renewable resources reflects the

m a r k e t value of the resources, i.e the demand and supply conditions This explains why oil has a higher value than, for example, coal Depending on use and emissions a value m a y be added I f oil is used as fuel, emissions f r o m incineration are added The Model only takes into account the ELU-index for important emissions and for the use o f non-renewable raw materials Effects on biodiversity caused by forest m a n a g e m e n t and similar environmental impacts have also been assigned an ELU-index in this Model However, the impact is minor

3.3 Data

The input data for the Model includes prices, efficiencies, costs of production and transport The fibre furnish and energy needs for each p a p e r quality are specified F o r each type o f pulp, the need for w o o d and energy and the emissions

to the environment f r o m the production process are specified D a t a sources include the Swedish Pulp and Paper Research Institute [19] and M o D o C o m p a n y databases D a t a f r o m G e r m a n y is assumed to reflect the situation in the whole of Western Europe Vass and Haglind [20] conducted a Swedish literature review of the environmental consequences of utilizing waste paper The review contains valuable data about sludge, chemical use, transports, use of energy and emissions

to air and water It is worth nothing that the data available for Sweden is considered reliable whilst that for the rest o f Western Europe could be improved

An extensive collection o f data on the production and trade in Western Eu- ropean forest products has been carried out for 1990 [1] This was the year for which the most up-to-date data for the countries studied could be found

116 S Bystr6m, L L6nnstedt /Resources, Conservation and Recycling 21 (1997) 109-127

4 R e s u l t s

In the following two examples we have forced the model to save forests in Scandinavia by recycling fibres Given the restrictions, it optimizes the use o f waste paper for energy recovery and recycling In the first case we minimize the produc- tion cost for the forest industry, and in the second example we minimize the load

on the environment as measured by the ELU-index

In 1990 the utilization rate in Western Europe, excluding Scandinavia, was 53% [1] It is unlikely that the rate will decrease in the future, on the contrary, it is likely

to increase When calculating the optimal solution the model is allowed to use a range for the Western European utilization rate Given the economic, technical, and practical limits for the utilization rate precisely defining the upper range end is difficult We have assumed, therefore this limit is 20 percentage units above the present level, i.e 73% When economic optimization is made, the utilization rate for Western Europe, excluding Scandinavia, ends up at the higher limit, i.e 73% When

an environmental optimization is made the utilization rate ends up at the lower limit, i.e 53%

4.1 Optimal economic distribution among products

In this example an economic optimization is made, i.e the marginal revenue for the forest industry is optimized Given the 'forced' utilization rates for the Scandi- navian forest pulp and paper industry the model is allowed to use the recycled fibres

in whatever production processes maximize revenue F o r the forest industry in the rest of Western Europe, it finds a solution within a utilization rate between 53 and 73% As noted above, the economic solution is found at the upper limit

Fig 2 shows the total environmental impact for Western Europe measured as change in the ELU-index when the overall utilization o f recycled fibres in Scandina- vian paper and board production changes Furthermore it illustrates the difference

Million ELU

19

18 • -,.~.,

h ~ s ;ile e l

16

15

14

_ , , ~ 1 I ~ ~ r

12

D B = - f f ~le, n E

11

j =,~,1 , -B ~ -

10

0 5 10 15 20 25 30 35 40 45 50 55 60 65

Utilization of DIP in Scandinavia (%)

Fig 2 Consequences at maximization of the marginal revenue for the environmental load, measured by the ELU-index, of a forced increase of the Scandinavian utilization rates of de-inked pulp (DIP) and a fixed utilization rate, 73%, for the rest of Western Europe

S Bystrrm, L Lrnnstedt / Resources, Conservation and Recycling 21 (1997) 109-127

Table 2

Increase in environmental impact in ELU/ton product for every 10% increase in recycled fibres

117

Hydroelectric power Fossil electricity

Newsprint Office p a p e r Newsprint Office paper

in load depending on whether the electricity in Scandinavia is hydroelectric or based on fossil fuels

If electricity is produced from fossil fuels, and as the de-inked pulp utilization rate increases from 5 to 60%, the environmental load first decreases and later increases The curve is rather flat and has its minimum at a utilization rate of about 30% At the beginning thermomechanical pulp is replaced by de-inked pulp but this potential disappears gradually A pulp mill produces an energy surplus that is used for drying the paper web This energy surplus must now be replaced by energy produced from fossil fuel This means that the minimum level depends on the actual Scandinavian pulp production structure, i.e the balance between chemical and thermomechanical pulp production The disadvantage of recycling is greater if the

electricity is hydroelectric In this case the consequence o f an increased utilization

rate is a continuous increase in the oil consumption

Depending on source of electricity production, the total oil consumption will more or less have the same shape as the curves presented in Fig 2 The explanation

is to be sought in the ELU-index which heavily punishes use of fossil fuels and emissions o f carbon dioxide

4.2 Optimal economic distribution among newsprint and office paper, respectively

In another example, use o f waste paper is forced when producing newsprint and office paper As above, a comparison is made between hydroelectric power and fossil electricity The results are summarized in Table 2

If electricity produced by hydroelectric power is used for newsprint production, the increased use of recycled fibres has an adverse effect on the environment The index increases by 32 E L U / t o n newsprint for every 10% increase in recycled fibres

in the product The excess energy from the pulp mill (about 6 G J/ton pulp) can be used for drying the paper (Fig 3) However, a lot o f electric energy is used; 10.5

G J/ton must be added This corresponds to approximately 20 GJ of heat energy per ton if a condense turbine power plant is used If newspaper after consumption is used for energy recovery 11.5 GJ o f heat per ton will be produced Thus, in total the energy saving for the whole system when T M P is used is about 7 GJ o f heat per ton When paper is recycled as fibres the thermo-mechanical pulping process no longer converts electricity into heat energy which is needed in the paper-making

118 S Bystr6m, L L6nnstedt /Resources, Conservation and Recycling 21 (1997) 109-127

process This energy loss is compensated for by fossil (oil) energy which is the cheapest available alternative In addition to being a non-renewable resource, the burning of oil for energy produces emissions, of which carbon dioxide is the most important

If, on the other hand, the electricity for newsprint production is generated from fossil fuels, an increased utilization rate has a favourable environmental impact This is because in this case the electricity, used for producing TMP, is produced from fossil fuel in condensing power plants with low efficiency (40%) If the electricity is not needed, as is the case when waste paper is used, it is more efficient

to produce this heat directly from fossil fuel Thermal energy must be added to the de-inking process (2 G J/ton) and to the paper mill (5.1 G J/ton) Thus, instead of getting 6 GJ of thermal energy as in the first case, 7.1 GJ of heat per ton must be added (Fig 3) However, the use of electric energy is only 5.2 GJ/ton which is 5.3 GJ/ton less than when T M P is used Differences in the type of transport of wood and waste paper contribute only slightly to the differences in the ELU-index However, the index does indicate a small increase in environmental impact, mainly due to larger emissions

In Table 2, figures describing the environmental impact caused by changing the utilization rate of recycled pulp in woodfree office paper are also included The chemical pulp process converts about half of the wood used into pulp The remainder of the wood raw material can be converted to thermal energy that is normally used in the paper-making process The total use of electric energy when office paper is produced from virgin pulp is about 5 G J/ton (Fig 4) Excess energy from the pulp mill (about 7 G J/ton pulp) can be used for drying the paper If waste paper is used for energy recovery, about 11.5 GJ of heat per ton will be produced

E n e r g y r e c o v e r y

Wood 0,04 ton T$

, ~ ~ 1 ton F i l e r

~ 11,8Gd hat

1Q,80J e/

0 0 J hear

O~put: 11,8 ~1 hear

Fibre r e c y c l i n g , Wood 0,14 ton TS

OJel mat

IJ heat G,Jel

I)~15 ton DIP ~ O,14mwood

U e J d 7,10JImar Ooq~:

Fig 3 Use and production of energy in newsprint production