Energy consumption by industrial processes in the European Union

Enerw Vol. 19, No. II. DD. 1113-1129. 1994 ‘Copyright 0 1994 kkvier Science Ltd Printed in GreatBritain.All rightsreserved 036X-5442/94 $7.00 + 0.00

Pergamon

ENERGY CONSUMPTION BY INDUSTRIAL EUROPEAN UNION

PROCESSES

E. WORRELL,~ R. F. A. CUELENAERE,~ K. BLOK, and W. C.

IN THE

TURKENBURG

Department of Science, Technology and Society, Utrecht University, Padualaan 14. NL-3584 CH Utrecht. The Netherlands (Received 22 February 1994)

Abstract--Industrial

energy consumption in the European Union has been studied, the focus being on specific energy consumption of various industrial sectors. An analysis is made of the main structural factors (e.g., primary or secondary production, product types) that affect energy efficiency. The industrial sub-sectors and production processes considered are those that are most important from an energy point of view, namely, oil refining, petrochemicals, ammonia, paper, cement, and steel production. These sectors consume 18% of the primary energy in the EU. There are considerable differences between the energy efficiencies of industries in EU member states. If each sector were to apply “best practice technology”, then potential improvements in energy efficiency in the EU would be on average 15 f 4% for oil refining, 21 + 2% for ammonia, 25 k 5% for paper, 13 + 1% for cement, and 27 f 3% for steel. No analysis can be made of possible improvements in the energy efficiency in the petrochemical industry because insufficient statistics are available. An improvement in the quality of international statistics is necessary to produce more reliable assessments.

INTRODUCTION

Ways must be found of reducing anthropogenic emissions of greenhouse gases because there is a risk that they may lead to climate change. Climate change requires a global approach (see for example the Climate Treaty, as approved by the United Nations Conference on Environment and Development, Rio de Janeiro, 1992). Economic issues affect the response strategy. According to King and Munasinghe,’ key issues are the efficiency and equity of the responses of nations. One of the items that should be taken into account for an equitable burden-sharing is the difference in the industrial infrastructure of nations.’ Country by country assessments are required so that opportunities for emission reduction are identified and compared. With regard to the most important greenhouse gas, namely carbon dioxide (CO,), an obvious way is reducing the energy consumption by improving the efficiency of energy conversion and consumption processes. What is needed is a detailed analysis of current energy efficiency and of the options available for improving the energy efficiency of a nations’ industry. These analyses must take differences in the industrial structure into account. Energy efficiency analysis can be performed at several levels, ranging from an energy intensity analysis for each country to a detailed analysis of individual plants, as depicted in Fig. 1. Each desegregation step requires additional data. Howarth et al* and Nilsson* are among those who have investigated the energy intensities in various countries and the factors affecting the intensity. Countries are found to have different energy intensities, with the differences changing over time. At the national level, energy intensity is defined as the energy consumption per unit of gross domestic product (GDP). At the sectoral, level energy intensity is defined as the amount of energy consumed per unit value added. SchippeFv6 and Morovii et al5 have investigated the factors (or indicators) that affect the energy intensity in a number of countries. Cross-country energy intensity studies (i.e. covering several countries), however, can be inappropriate because they are influenced by differences in the economic structure of a country or sector. So far few cross-country energy efficiency analyses having used a physical approach that focus on the specific energy consump-

tTo whom all correspondence should be addressed. $Currently employed by the Ministry of Housing, Physical Planning and the Environment, The Netherlands. 1113

E. WORRELLet al

1114

Data Aggregation Level

Efficiency Analysis Level National

energy

intensity

Individual individual

plant efficiency

plant data

4

b Needed Amount

of Data

Fig. 1. Aggregation levels in energy efficiency analysis, from national efficiency down to unit-operations or equipment in individual plants. From top to bottom the analysis is performed at an ever lower aggregation level. With a lower aggregation level the amount of data required for a comparative analysis increases (width of the pyramid).

tion (SEC), are performed. However, these studies are preferable to energy intensity studies4 since they give a clearer picture of the technical differences between different sectors in different countries. The purpose of this study is to gain insight into the importance of, and the current energy efficiency in, the major energy consuming industrial sectors. We will concentrate on the member states of the European Union? (EU), because more data are available for these countries. Manufacturing industries (including oil refining) in the EU are responsible for about one-third of the primary energy consumption. First of all we will describe the methodology used in this study. Next, an overview is presented of industrial production and energy consumption in the EU. Thereafter we determine the amount of energy consumed by industry in the various EU member countries. From this overview we then select individual sectors for in-depth analysis. We concentrate on a limited number of material production processes which are responsible for more than 1% of the primary energy consumption in the EU. The selected industries are petroleum refining, pulp and paper production, the petrochemicals industry, cement production and the iron and steel industry. We perform a cross-country analysis of the energy efficiency in the selected sectors in the EU countries. We consider the differences in the production structure of each sector in the EU countries. Finally, conclusions are drawn concerning the industrial energy consumption in the EU and the differences in the energy efficiencies of EU countries. METHODOLOGY

This study deals with the specific energy consumption (SEC) of different industrial sectors in the EU. The SEC is defined as the amount of energy (in enthalpy) needed to execute a certain activity (e.g. the production or processing of a specific product). In the industries studied the activity concerns the production of a tonne of a specific product. The SEC is influenced by three main factors: type of products made, type of production process (which is partly related to the type of resources or feedstock used in the process, e.g. primary or secondary resources) and the efficiency of the current production processes. The efficiency can be improved. The type of primary energy carrier used can also affect the energy efficiency (for instance in boilers). TThe European Union is the former European Community which in 1988 consisted of 12 member states.

Industrial energy consumption in the European Union

I1 IS

We will not consider the variety of fuels available, but we will treat fuels as one single energy carrier in determining the potential for energy efficiency improvement, since industries in the EU are assumed to have (market) access to all types of energy carriers. A production process can be described by its inputs and outputs. The input describes the raw material (or feedstock) input (e.g. primary and secondary materials). The output describes the type and quality of the products. For our analysis it is necessary to assess the major input and output factors that influence the composite SEC of the sector. An important input factor is the distribution of consumption over primary and secondary resources, especially as far as the production of paper and steel is concerned. In the output the main differences can be found in the product quality. For example, the steel industry makes slabs and hot rolled and cold rolled products, each with a different SEC.7 Differences of this kind are also found in oil refining, and in paper- and cement-production. In this study the SEC of a process is expressed by Eq. ( 1). SEC, = SECL, + SEC,., / 77, (GJ/tonne),

il)

where SEC, = SEC, expressed as the demand made on primary energy carriers needed per tonne of products (GJ/tonne), associated with a certain industrial process p; SE& = the SEC of fuel per amount of product associated with a certain industrial process (in GJ/tonne); SEC,,, = the SEC of electricity per amount of product associated with a certain industrial process (in GJ,/tonne); 7, = the average efficiency of electricity production (i.e. the total electricity output of power plants divided by the total fuel input of the power plants as reported in OECD statistics,’ see Table 1). The factors SEC,-., and SEC,., are process characteristics, which are influenced by the type of resources, type of products and efficiency factors in the process. We take Q to be the efficiency of public electricity generation in the member state, unless stated otherwise. The efficiency is calculated on the basis of the primary energy consumption for electricity generation. We do not account for efficiency differences caused by combined heat and power (CHP). In OECD countries, the heat delivery of industrial CHP is converted to fuel, assuming a fictional boiler efficiency. This means that in OECD statistics the CHP heat and electricity production cannot be linked with final users but is partly included in the transformation sector. Within an industrial sector several processes can be used in parallel to produce a product or material, Table

I. Fuels. electricity and primary energy consumption in the EU-member states in 1988 (excluding grid losses), as derived from OECD/IEA-data.Y

Country

Fuel

Electricity

Electricity Generation Efficiency

Calculated Primary Energy

(PJ)

(PJ,)

(%I

(PJ)

Belgium (B)

1217

204

38.1

1920

Denmark (DK)

480

144

36.4

798

4885

1015

38.3

8753

Germany (D)

6870

1446

36.9

11485

Greece (GR)

493

97

36.4

857

Ireland (IR)

262

39

36.6

407

4073

714

39.3

6357

France

(F)

Italy (I) Luxembourg

(L)

112

15

33.3

141

Netherlands

(NL)

1924

256

40.2

2704

Portugal (P)

412

Spain (E)

2001

411

37.1

3545

United Kingdom (UK)

5280

956

37.5

8737

EU

28010

5372

37.8

46365

E. WORRELL eta1

1116

each with its own SEC. Therefore, the composite SEC of a sector is a function of the distribution the different processes utilised within the sector. This is described by

over

p=ll

SEC = c SEC, x V,/V p=l

(GJ/tonne),

(2)

where SEC = Composite SEC of an industrial sector in a country with n processes, expressed in GJ/tonne; SEC, = SEC for process p (process with a well described input (feedstock) and output (product)), expressed in GJttonne; V, = Production volume of product p, expressed in tonne; V = Total sum of production volumes of n products p, expressed in tonne. Using Eq. (2) it is possible to decompose the SEC of a sector into the processes used and the energy efficiency of these processes. The efficiency can be expressed as a deviation from the so-called ‘best practice’ efficiency of a process, or as the difference between the current SEC of the process used and the ‘best practice’. ‘Best practice’ is here defined as the lowest SEC observed in a sector or plant in Europe in the reference year. This implies that all plants could in principle achieve this level of energy efficiency,8 and is therefore a useful point of reference. The differences in the energy efficiency of different countries are then expressed as the difference between the current SEC and the ‘best practice’ SEC for each sector. The composite ‘best practice’ SEC is given by

p=?l

SEC,,

= c SECBP,p x V,/V (GJltonne), p=l

(3)

where SE& = composite ‘best practice’ SEC of a certain industrial sector (with n processes), expressed in GJ/tonne; SECBP.p = the ‘best practice’ SEC of process p (process with a well described input (feedstock) and output (product)), expressed in GJ/tonne; V,, = production volume of product p, expressed in tonne; V= total sum of production volumes by n processes p, expressed in tonne. The processes involved and the ‘best practice’ SEC are described for the investigated sectors. The value of the ‘best practice’ SEC depends on many process characteristics. The most important characteristics are taken into account in this study. ‘Best practice’ indicates the energy efficiency improvement potential, although it does not include new or other opportunities for energy efficiency improvement that have not yet been implemented. Therefore, the total future potential for energy efficiency improvement is larger than the values found in a comparison of current and ‘best practice’ SEC.

INDUSTRIAL ENERGY CONSUMPTION IN THE EU

A summary of the national energy consumption in the EU member states in the reference year 1988 is presented in Table 1. In determining production quantities and energy consumption figures we have relied on (international) statistics and information provided by international agencies. Table 2 shows the energy consumption of the industrial sectors in the EU. The industrial sector in the EU (including oil refining) is responsible for 36% of the total primary energy consumption. This value is low compared to that for Japan (46%) but high compared to the U.S.A. (31%).9 The average figure for OECDcountries is 36%.9 The industrial energy consumption can also be compared on a per capita basis; for the EU this figure was 51 GJ/capita, and for the U.S.A. and Japan respectively the figures were 102 and 63 GJ/capita in 1988.9 The figure for the OECD is 73 GJ/capita.’ Table 2 gives figures for the energy consumption of different industrial sectors. Many sectors produce a large number of different products. For a cross-country analysis one needs to investigate the energy efficiency of uniform products. In Table 3 we present estimates of the demand that various products make on primary energy carriers and the percentage of the primary energy consumption used for these products in the EU. Since, it was not always possible to obtain data on the distinguished products for the reference year, that introduces a small inaccuracy in the relative contribution to the primary energy consumption in the EU.

Industrial

energy consumption in the European Union

Table 2. Energy consumption

Sector

in industrial

sectors in the European

Fuel

Electricity

(PJ)

(PJ,)

Primary Energy (PJ) s.b

1117 Union.’

Share of EU Consumption (%)

Iron & Steel

1831

304

2635

5.7

Refineries

1392

74

1588

3.4

Chemical

3509

570

5017

10.8

163

217

737

1.6

I142

168

1586

3.4

Transport equipment

137

120

455

I.0

Machinery

410

204

950

2.0

54

47

178

0.4

Food & tobacco

582

I95

1098

2.4

Paper, pulp & printing

372

172

827

1.8

Wood products

33

44

149

0.3

Construction

120

22

178

0.4

Textile & leather

208

II3

507

I.1

Non-specified

496

I44

877

1.9

IO243

2395

16747

36.1

Non-ferrous Non-metallic

metals minerals

Mining & quarrying

industry

TOTAL a. Primary energy consumption for electricity Table I.

is calculated

includes fuels and feedstocks; b. The primary energy consumption by use of the average generation efficiency in the EU, mentioned in

ENERGY EFFICIENCY

ANALYSIS

Table 3 shows which processes are the most important from an energy point-of-view. In this study we concentrate on production processes which consume more than 1% of all the primary energy in the ELJ. These processes are the production of oil derivatives (3%), paper (2%), ammonia (I%), petrochemicals (5%), cement ( 1%), and steel (6%). These processes cover nearly 18% of EU primary energy consumption. Table 4 presents the production volumes for each EU member state. Table 5 gives figures for the energy used to produce the selected products in each EU member state. In Fig. 2 the total primary energy consumption in the six selected sectors is depicted as a percentage of the national primary energy consumption in each EU member state. Figure 2 shows that the percentage varies strongly from country to country. We next discuss the specific input and output factors which influence the composite SEC in each sector.

Petroleum

refining

Crude oil is separated and processed into a number of fractions or products. The fractions are divided into light to heavy fractions, according to the molecular weight. The main input variation is the type of crude oil. The type of crude oil can influence the energy consumption of the Crude Distillation unit by 24%,‘8 or can alter the SECBp of each product with 4-8% (see Table 6). In practice countries import several types of crude oil, reducing the error. We cannot take this variation into account, because no data concerning the crude oil types used are available. The output is always a mixture of products. The production of light fractions consumes more energy, since more processing steps are involved. We distinguish six fractions: gases (LPG and refinery gas), gasoline, kerosene, gasoil (including naphtha), fuel oil and others. Unfortunately, we cannot take into account the influence that modem heavy residue conversion (hydroconversion) has on the SEC. Hydroconversion units produce a higher proportion of light fractions, which have a higher economic value and also a higher energy consumption. However, since no separate throughput figures for hydroconver-

E. WORRELL et al

1118

Table 3. Energy consumption in the EU for the production of a number of products. production volume is given in ktonnelyear.

ProductI Process

Resources

Production volume

Primary energy demand

(ktonne)

G’Jt =

Primary energy demand (S of total)

137774 b

2635

5.7

Steel

Ore, scrap

Aluminium

Alumina

2319’

369 d

0.8

Copper

Ore, scrap

1266’

14 g

0.0

Zinc

Ore

1719 f

67 g

0.1

Alumina

Bauxite

4900 8

72 g

0.2

Ammonia

Fossil fuels

12479 h

443h

1.0

Chlorine

Salt

8490 s

287 g

0.6

Soda Ash

Salt

5750 ’

75 E

0.2

Phosphor

Ore

240 8

408

0.1

Methanol

Natural gas

34 i

0.1

Oil products

Crude oil

463725 j

1421

3.1

Petrochemicals

HC Feedstocks

27734 ’

2237 ’

4.8

Styrene

Ethylene, benzene

3OOOg

27 p

0.1

VCM

Ethylene, chlorine

4360 B

36 g

0.1

Polyethylene

Ethylene

5955 m

36 g

0.1

Polypropylene

Propylene

2440 ”

29 8

0.1

PVC

VCM

3930 s

23 g

0.1

Cement

Limestone

171922 a

665 o

1.4

Building bricks

Clay

47760 p

133.5 g

0.3

Glass

Sand, cullets

20410 q

181.9 q

0.4

Paper

Pulp, waste paper

35010 I

778.0

1.7

1. m. n. 0.

P. q. r.

The

2000’

Unless stated otherwise, the energy figures are derived from OECD-data? Source: Ref. 10. Source: Ref. 11. The figure given is valid for 1990. Source: Ref.12. Only primary production. Source: Ref.13. Total 1988 production figure. Source: Ref.14. Production is valid for 1985. Source: Ref.15 Source: Refs. 16 and 17. Figure is valid for 1985, excluding feedstock. Source: Ref.15 Total volume refinery products. Source: Ref.18. Because all cracking products are produced in one process (except for a part of the aromatics), these products (ethylene, propylene, butadiene and aromatics) are added together. This figure excludes Belgium. Sources: Refs. 11 and 19. Energy consumption has been estimated to equal the oil consumption in the chemical industry. Unfortunately no detailed energy consumption figures are available. Estimated production figure in 1986. Only capacity figures are available for Belgium. Source: Ref.20. Estimated production figure in 1986. Only capacity figures available are available for Belgium and Italy. Source: Ref.21. Source: Ref.22. Figure is valid for 1985. The 1988 production (30877 m3) is not available in tonnes. Glass products are: container glass (65%). flat glass (25%). Glass fibreitechnical glass (5%) and others (5%). Source: Ref.14. Paper production figures are provided by the OECD. Source: Ref.23.

Industrial Table 4. Figures for the production Country

energy consumption

in the European

of some selected materials

Union

1119

in the various EU countries

(in ktonne/year).

Refineries’

Paperb

Belgium

27345

1137

307

Denmark

1956

343

0

France

76174

6313

2011

Germany

85100

10576

2215

Greece

15951

270

296

0

12392

959

Ireland

1387

0

210

0

1869

271

83070

5512

2122

2966’

40522

23762

Italy Luxembourg Netherlands Portugal Spain United Kingdom __ _~ __~_~~~ EU

0

0

PetrochemicaW’ na.

Cement’

steel’

6766

11161

1597

650

5179

26827

19122

8366

27700h

41023

0

582’

3661

54410

2475

3278

3227

3419

5518

8624

681

118

403c

6743

811

51693

3408

581

2306’

28217

11886

8493 1

4295

1341

5287

15764

18950

35010

12479

27734

171922

137774

496641

0

Ammonia’

0

a. The figures represent the total throughput of the refineries. Source: Ref.18. b. Production figures for paper production have been taken from Ref.22. C. Production figures for ammonia production have been taken from Ref.16. d. The sources for me production figures are. Refs. 11 and 16. No production figures are available for Belgium. e. Since no 1988 production figures are available, production data for 1987 are given. f. Production figures are valid for 1989 and provided by Cembureau. Source: Ref.23. Figures for the total production of primary and secondary steel. Source: Ref.lO. ;: The production figure of 1990 is presented, because the clinker production figure could only be obtained for this year. Source: Ref.24. i. Figure for 1989. Clinker production in Luxembourg was 1049 ktonne, of which 72% is exported. Source: Ref.25

sion units are available (only capacity figrues are givenz9), we cannot correct for this factor. Table 6 shows the SECBp for each fraction produced in a modern standard refinery. Pulp and paper production Paper is produced from wood pulp and waste paper. The main input factors are the amounts of pulp and waste paper used for the production of paper. We also take into account the pulping processes used. We distinguish chemical, mechanical and other pulping processes, each of which has its own SECBP,p). The SE&, for de-inking and pulping of waste paper is assumed to be 0.4 GJ fuel/tonne and 1.4 GJ, electricity/tonne.3’ The main output factor is the paper grade. The paper grade is defined by the relative amount of waste paper used and determines how much energy is consumed by the paper machine. We distinguish five paper grades: newsprint, printing, sanitary, packaging and others. There is no specific information about the composition of the different paper grades in each country. Therefore, we use as representative figures in the analysis the SEC,r,r-figures quoted in Table 7. Ammonia production The SEC is influenced by the type of feedstock. Ammonia is produced by the reaction of nitrogen and hydrogen. The main hydrogen production processes used in the EU are steam reforming of natural gas and partial oxidation of oil residues. The SEC, of modem partial oxidation units is 30 GJ/tonne,33 and for older units up to 30% higher. I6 In the EU only 8% of the production capacity is based on partial oxidation. 34 In the analysis we use the ICI-AMV steam reforming process as ‘best practice’ with a SE& of 28 GJ/tonne.34

13 7

219 8 2 107

297

40

7

239

GelllXUlY

185

25

179

281

1588 (3.4%)

Netherlands

Portugal

Spain

United Kingdom

EU

126

78

28

41

0

46

17

5

110

0

78

71

2237 (4.8%)

316

665 (1.4%)

82

85’

27

59 194

7’

4

135

273

2

282

9

60

8 5

108

531

115

9

374

2d

5

Cement’

93

Petrochemicals”

2633 (5.7%)

367

216

17

99

63

419

5

14

815

388

10

237

Steel’

Energy consumption figures from OECDIlEA statistics. Source: Ref.43. Energy consumption figures from OECD/IEA statistics, which include pulp and paper production and also printing & publishing. Source: Ref.9. Figures represent only fuel consumption. The figures have been calculated on the basis of data about production volume (see table 4) and specific energy consumption figures. Source: Ref.16. Figures represent the oil consumption of the total chemical industry (including feedstocks) as given in OECDIIEA statistics. 1987 data are presented for Italy, Portugal and Spain. Source: Ref.9. Cembureau gives energy consumption figures for nine EU-countries, excluding Belgium, Greece and the Netherlands. For Greece the energy consumption has been estimated as equal to the OECDIIEA figures for the non-metallic minerals production. The figure for Belgium has been calculated on the basis of clinker production and SEC figures provided by the Belgian Cement manufacturers’ organisation.26 f. Figure taken from Ref.27. 8. Figures taken from OECDIIEA statistics. Source. Ref.9.

0

Luxembourg

IdY

Ireland

86

131

246

0

France

12

12

Ammonia’

18

26

PapeP

Denmark

Refineriesa

14

_

Belgium

country

Table 5. Overview of the primary energy” required for the production of six materials in the various countries of the EU in 1988 (in PJ/year). Between brackets in the share given of the total EU primary energy consumption (46365 PJ) for the consumption per sector (in %). Primary energy consumption for electricity production has been calculated using the average efficiencies for each country. .. ~.._

Industrial

energy consumption

in the European

Union

I121

60%

DK

F

D

m

GR

IR

NL

studied industries 0

P

E

UK

EU

other industries

Fig. 2. Primary energy consumption of the six major industrial sectors in 1988 as share of the total national primary energy consumption, depicted for each EU member state. Also shown is the distribution of the total industrial primary energy consumption.

Table 6. ‘Best Practice’ SEC for six types of oil refinery products.‘(’ Oil refinery product

SEC,; (GJ/tonne)

Gases (LPG, refinery gas)

1.3

Gasoline

3.8

Kerosene

1.6

Gasoil (including

a.

Petrochemical

naphtha)

3.2

Fuel oil

1.8

Others

1.8

The SEC,, is based on a typical standard refinery, consuming 6.5% of throughput, with a mixed feedstock of Arabian light and Brent blend.

indust

The production of petrochemicals by steam cracking of hydrocarbon feedstocks is the single most energy-consuming process in this sector. The input factor is the type of feedstock. The processing of lighter feedstocks consumes less energy. The European petrochemical industry uses a mixture of LPG, naphtha and gasoil. OECD statistics43 give separate consumption figures for the various hydrocarbons. The output consists mainly of ethylene, propylene, benzene and butadiene, which are used as intermediate feedstocks for a large number of chemicals. Only aromatics are produced by processes other than steam cracking, e.g. by catalytic reforming. We cannot take this factor into account, because statistics do not distinguish between these processes. The energy consumption data comprise the entire chemical sector. Therefore, it is impossible to make an accurate calculation of the energy efficiency with existing international statistics. For some member states, production data are not available at all (e.g., Belgium)

E. WORRELL et al

1122

Table 7. Shares of pulping processes and paper types in paper production in 1988.23 The SE& by Komppa”’ and for paper making by Ref. 32.

Country

Paper Types

Pulping Processes

SEC,, I Mechanical

Chemical

is given for pulping processes

Others

Newsprint

Printing

Sanitary

Packaging

Others

Fuel (GJ/tonne)

-2.7

11

11

3.2

6.9

5.3

5.0

5.0

Elec. (GJ./tonne)

9.7

-1.8

-1.8

2.1

119

2.4

1.8

1.3

Belgium

50%

21%

29%

10%

62%

9%

16%

3%

Denmark

0%

0%

100%

0%

37%

4%

59%

0%

24%

70%

6%

6%

39%

5%

46%

4%

Germany

68%

28%

4%

8%

44%

7%

36%

5%

Greece

100%

0%

0%

4%

22%

30%

30%

14%

0%

0%

0%

100%

0%

France

Ireland 68%

12%

20%

5%

40%

5%

45%

5%

100%

0%

0%

12%

28%

7%

50%

2%

Portugal

0%

100%

0%

0%

22%

7%

66%

5%

Spain

14%

86%

0%

5%

24%

6%

53%

12%

United Kingdom

100%

0%

0%

12%

28%

10%

42%

7%

EU

39%

56%

6%

8%

37%

7%

43%

5%

Italy Luxembourg Netherlands

or are not available for the reference was closed in 1984.

year (Italy, Portugal and Spain). In Greece, the naphtha cracker

Cement production Cement is produced by burning lime-stone to produce clinker. Clinker is blended with other constituents and bline, to produce various cement types (depending on the clinker content). Clinker production is the main energy-consuming step in cement production. The concentrations of several components in the limestone affect the SEC only slightly. The raw materials for the production of Portland-cement are blended until the mixture contains 76-78% calcium carbonate,35 and therefore the SEC is hardly influenced. The main output-factor influencing the SEC is the amount of (Portland) clinker produced in relation to the total cement (blend or composite) production. Clinker can be produced by two process types: the wet and dry type. Several configurations and mix-forms (semi-wet, semi-dry) exist for both types. The dry-type is the modem and more energy efficient configuration. The wet-process is used because it is less sensitive to the (low-grade) fuels used. The fuel mix for cement production differs from country to country. However, we were not able to obtain statistical data concerning the nature of the alternative fuels used and on the volumes consumed. The fuel mix does not influence the SEC.36 The SE& is assumed to be 3.3 GJ fuel/tonne fuel for a dry process kiln with a 5-stage pre-heater.37,38 Electricity demand is assumed to be 0.3 GJ/tonne .39 The figures are corrected for the amount of energy used to blend the cement; it is assumed that the energy consumption for blending is 0.2 GJ/tonne.37 Iron and steel production The most important input-factor influencing the SEC is the feedstock: iron ore and scrap for primary steel [Basic Oxygen Furnace (BOF)] or scrap only for secondary steel [Electric Arc Furnace (EAF)]. In this study, direct reduction is not taken into account because it makes only a very small contribution to the EU iron production (0.3%40). The production of primary steel consumes relatively more energy but produces a higher steel quality. In the BOF-process the amount of scrap used is different for each plant. We will correct for the amount of scrap input in the BOF-process on the basis of Ref. 48. The

Industrial

energy consumption

in the European

Union

1123

Table 8. SE& for steel production (excluding coke production). Primary steel and rolling SEC is given by Ref. 7 and the SEC,, for the EAF process is given by Ref. 41. Process/product

Electricity (GJCtonne)

Fuel (GJ/tonne)

BOF - slab

14.2

0.4

BOF - Hot rolled

16.1

0.7

BOF - Cold rolled

17.2

1.3

1.8

1.9

EAF - Wire rod

SECBP.r given in Table 8 are valid for a 10% scrap input in the BOF-process. The main output-factor is the product type. We distinguish four types: slab, hot rolled product, cold rolled product and wire rod. The SE&, for the various products is given in Table 8. The SEC& for the BOF-route is based on the Hoogovens steel plant in The Netherlands’ (corrected for the amount of scrap in the BOF-input) and for the EAF-route the SECsp is based on the Badische Stahlwerke plant in Germany.4’ RESULTS

AND DISCUSSION

In this section we discuss the effects of the major input and output factors that have been taken into account in the analysis. We will also discuss the results of energy efficiency analysis and compare the efficiency levels in the EU countries. We will also evaluate the effects of our assumptions. Petroleum refining is plotted versus the current SEC (derived from statistics) on the basis of the In Fig. 3 the SE& data for a standard refinery (see Table 6). We have used the throughput and production figures of

3 2 3.6 g

y 2.4 rn

1.2

3

0.0

_.__I B

DK

D

F

GR

IR

I

L

NL

P

E

UK

EU

Country m

‘Best Practice’ SEC

n

Deviation 1988 SEC

Fig. 3. The SEC (GJ/tonne) of petroleum refining in each EU member state, which accounts for differences in product-mix. The total bar represents the 1988 SEC. The black part of the bar is the 1988 ‘best practice’ SEC.

E. WORRELLet al

1124

Eurostat18 and energy consumption figures from the Energy Statistics of the OECD.43 The energy consumption figures are composed of fuel consumption, refinery losses and electricity consumption. Comparison of throughput figures from Eurostat” and OECD43 show average deviations of 6% (ranging from 0 to 28% for individual countries). In oil consumption deviations of 16% on average have been found (ranging from 8 to 38%). This influences the results by 12% on average (range of 4-24%). The use of modern heavy residue conversion units introduces an inaccuracy for countries where a relatively large hydroconversion capacity has been installed. The inaccuracy is compensated by the composition of the product mix (more light products with a higher SEC,,); this reduces the error by 2%. The capacities vary from 0 to 6% (Germany) of the CDU-capacity,29 which introduces a maximum error of 12, 6, 4, and 3% for Germany, Portugal, The Netherlands, and Italy, respectively. For other countries, the error is smaller than 1%. Because of the large uncertainties one must be cautious about comparing the efficiencies of EU member states. Pulp and paper production

Figure 4 presents the composite SEC for each EU member state for paper production, as a function of the pulp/paper-ratio. The line in Fig. 4 represents the calculated energy consumption for the average production in the EU. Errors are introduced because the energy statistics include the printing and publishing sector. The error is difficult to estimate because separate energy consumption figures for the printing and publishing sector are not available. National statistics could make it possible to separate the two sectors. However, in our methodology we only use international statistics. Using the breakdown for The Netherlands4 the error in the results is estimated to be 15%. Figure 4 shows a comparable potential for energy efficiency improvement, with three deviations (Denmark, Greece and the U.K.). A comparison of the relative gross output figures45 for printing and publishing with paper making does not explain the high SEC for these countries. Water temperature influences the fuel efficiency of the paper mill by approximately l%/°C.46 The average ambient temperature varies by 5°C (derived from Ref. 47) from an average figure of 12°C in the EU, introducing an error of 5% into the fuel use. Therefore, the total error in the results is estimated to be not more than 20%. Ireland, Luxembourg and Portugal are not included. Portugal is a pulp-exporting country which produces more pulp than paper. Luxembourg does not produce paper. Ireland produces only a very small volume of paper (only two mills); the results are therefore unreliable, due to the relative large share that the printing and publishing sector have in the total energy consumption.

DK

35-

0!

I

0

t

0.2

0.1

0.3

0.4

I

0.5

t s

Ratio pulp/paper production -

1988SEC

0

‘Best practice’ SEC

Fig. 4. Energy efficiency of the pulp and paper industry in the EU. The SEC is depicted as a function of the pulp/paper-ratio. The upper points (H) depict the 1988 energy efficiency. The lower points (0) give the 1988 ‘best practice” energy efficiency. The calculations take the pulp/paper-ratio, as well as the paper types into account. The line represents the EU-average (pulping-processes and paper-types), using the 1988 ‘best practice’ SEC.

Industrial

energy consumptton

in the European

Union

1125

Ammonia production Figure 5 depicts the SEC for ammonia production in the different member states. The horizontal line represents the ‘best practice’ SEC of the AMV-process. The SEC of the AMV-process depends on local conditions and plant capacity, and varies between 28 and 30 GJ/tonne,48 which introduces an uncertainty of 7% in the SECBP,p. The low values for Ireland and Spain can be explained from the fact that these countries have recently completely retrofitted their (relatively small) ammonia plants. The use of naphtha and fuel oil in Germany and Greece causes a maximum error of 4%, due to the higher SEC& for this feedstock. The total error is estimated to be not more than 11% for Germany and Greece and 7% for the other member states. Petrochemicals It is unfortunate that because of the lack of detailed statistics no detailed analysis can be performed for the second largest energy consuming sub-sector (5% of total primary energy consumption) in the EU. Cement production Figure 6 shows the energy efficiency for cement production in the EU member states. We have depicted the current SEC as a function of the clinker/cement-ratio. Both cement production and energy consumption figures come from the same source (Ref. 22). Clinker production figures are not collected centrally, and were provided for this study by the national cement producers’ organisations. The relatively high figure for The Netherlands is explained by the use of one wet-process plant in the reference year (which was closed in 1990). Unfortunately no clinker production figures are available for Greece and Italy. The specific fuel consumption for these countries is 5.0 and 3.3 GJ/tonne cement respectively. For Germany we have used 1990 production and energy consumption figuresz4 because 1989 figures were not available for this study. The uncertainties in the SEC& range from 3 (for countries with a high clinker/cement-ratio) to 10% (for countries with a low ratio), due to the uncertainty in the energy needed for drying the cement. It is not possible to estimate the total error in the results, because the statistical errors are unknown.

5or------

1

I

GR 6

P

D

40 F

EU

UK

NL

IR

-

-

10

0

-I 6

1

I

DK

1

T-

I

GR

IR

L

NL

’ UK

EU

dountry

Fig. 5 The energy efficiency (depicted as SEC) of ammonia production in the EU member states. The horizontal line represents the 1988 ‘best practice’ SEC of 28 GJ/tonne.

;

E. WORRELL et al

1126

5 OK 4.5UK 4= E

IFi

3.5-

+

3-

+

2.5-

L0 $

1.5l-

0.5

0.6

0.7

Clinker/cement ratio Fig. 6. Energy efficiency of cement production in the EU member states. The specific fuel consumption ((X/tonne cement) is depicted as a function of the clinker/cement production-ratio in 1989. The upper points (m) depict the 1989 SEC, while the lower points (0) on the line represent the ‘best practice’ SEC.

Iron and steel productoin

Figure 7 shows the current SEC of steel production as a function of the share in the total steel production. The vertical position of the ‘best practice’ SEC is of the energy consumption figures in Table 8. The EAF-production figures statistics,‘O and the product types are taken from data published by IISI.40 We

of EAF produced steel calculated on the basis are taken from OECD have corrected for the

25

I

0%

1

10%

%

1

30%

I

I

40%

50%

0

60%

I

,

70%

30%

I

%

I

100%

Share EAF

m

Current SEC

•I

‘Best Przxtice’ SEC

Fig. 7. Energy efficiency of steel production in the EU member states. The energy efficiency is depicted as SEC (GJ/tonne steel) and as function of the share of EAF produced steel in the total 1988 steel production. The upper points (m) represent the 1988 SEC, while the lower points (Cl) represent the 1988 ‘best practice’ SEC. The latter takes three major products (slabs, hot rolled products and cold rolled products) into account. The upper line represents the SEC,, for the production of cold rolled sheets and the bottom line the SEC,, for the production of slabs.

Industrial energy consumption in the European Union

1127

use of scrap in the BOF-process on the basis of Ref. 49. The low SEC for Luxembourg is explained by the high scrap input in the BOF-process (up to 30%).40 Because no 1988 scrap consumption figures for the BOF are available for Belgium,4g we estimated it on the basis of the total scrap consumption and the consumption by EAF plants. The differences in the SEC are comparable to those listed in the literature.4g A comparable methodology was used in Ref. 49, whereas the data were collected by means of a questionnaire sent out to the steel industries. Small differences are caused by the figures for the primary energy demand required to produce electricity. In particular, the countries using EAF-mills show a large deviation from the ‘best practice’ SEC. This is probably due to the age of the plants and the fast developments in EAFtechnology. Ireland is not depicted, because the energy consumption statistics for this country also include non-ferrous metal production. 9 The high SEC for Denmark cannot be explained. Although Greece has BOF-capacity, in 1988 all steel was produced using the EAF-route.“s4’ There are differences between the statistics of IEA/OECD and those of Eurostat, in the transformation sector (refineries) and the chemical industries, especially with regard to oil and natural gas consumption. Electricity consumption figures of both sets of statistics are comparable. The deviations are distributed over all countries. The IEA indicates that most countries have difficulty in giving a detailed breakdown are regarded as by fuel for industry consumption, 9 although the total fuel and electricity consumptions accurate for most EU countries. 42 The data on the transformation sector are still being improved in the IEA statistics.42 Deviations result from the methodologies that the international agencies use to process the data from individual countries and are also due to individual non-systematic errors in the statistical data, which are sometimes improved or recalculated. The uncertainty in the value for the ‘best practice’ SEC depends not only on the uniformity of the input and output factors, but also on plant scale and local circumstances. We have taken the most important input and output factors into account. In the analysis of the individual countries we have used the national electricity generation efficiencies. This can disguise the size of the differences, since the efficiency of public electricity generation cannot be influenced by the industrial sector. The application of the average EU efficiency introduces no deviation in the results for cement and ammonia production, since we take only fuel into account in these sectors. For refineries and pulp and paper production no deviations are found and for iron and steel production there is a maximum deviation of +8% (relative to the potential for energy efficiency improvement).

CONCLUSIONS

We have presented an overview of energy consumption per process/product for the EU member states in the year 1988. The production in the sectors refineries, pulp and paper, ammonia, petrochemicals, cement and steel is responsible for more than 1% of the EU primary energy consumption each. Industry in the EU is responsible for 36% of the total primary energy consumption. The sectors investigated are responsible for 18% of the primary energy consumption (or half the industrial energy consumption). From this it can be concluded that the industrial structure of the EU, as far as energy consumption is concerned, is dominated by heavy industry. The energy consumption of the selected sectors of industry varies from 10% (Ireland) to 50% (Luxembourg) of the national energy consumption. It has been shown on the basis of the OECD statistics that in the industrial sectors studied there are considerable differences in the energy efficiency between the EU member states. The deviation from the SECsp is an estimate of the potential for energy efficiency improvement that can be achieved by implementing the ‘best practice’ technology. These results are presented in Table 9. It should be noted that efficiency improvements, over and above the best practice technology can be achieved. The high deviations for Denmark (for oil refineries, paper and steel) could be caused by the relatively small size of the sectors, and hence larger errors in statistical data. Recent data were not always available. National or international statistics are often not detailed enough, and the various statistics show deviations. Comparison of the energy consumption figures for the industrial sectors given by several statistical sources show differences for some countries and sectors. Large deviations occur in the transformation sector (petroleum refineries), which makes a comparison of efficiencies difficult. For an assessment of the energy efficiency of the petrochemical industry one needs more and better data on energy consumption and production than are currently available. In the analysis of the cement industry

E. WORRELL

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eta1

Table 9. Estimated potentials for energy efficiency improvement (in W) compared to a ‘best practice’ case, for the selected processes in each of the EU member states and the EU. The uncertainties in the figures are given in the text. Country

Refineries

Pulp & Paper

Ammonia

Cement

ken & Steel

30%

25%

19%

30%

55%

Belgium

I%

17%

Denmark

0%

55%

France

13%

22%

21%

19%

27%

Germany

19%

17%

28%

0%

23%

Greece

0%

55%

35%

n.a.

51%

Ireland

41%

n.a.

11%

16%

n.a.

8%

25%

23%

n.a.

36%

Italy

1%

20%

Luxembourg

-

Netherlands

25%

13%

16%

30%

8%

Portugal

13%

n.a.

34%

0%

27%

Spain

27%

19%

I%

10%

42%

United Kingdom

14%

41%

18%

21%

26%

EU

15%

25%

21%

13%

27%

we have used data from the national cement producers’ associations. Unfortunately not all associations collect clinker production data. The calculations presented give an overview of the cross-country differences, and give an indication about where energy efficiency can be improved effectively. The potential for energy efficiency improvement can be calculated more accurately using an approach that starts with processes and unit-operations. Furthermore, it is necessary to improve the accuracy and availability of (international) statistics. Acknowledgements-The authors wish to thank the Ministry of Housing, Physical Planning and Environment and the National Research Programme on Global Air Pollution and Climate Change for supponing the research under project number 852084. They also acknowledge the help received from Aalborg Portland (Denmark), Agrupacion de Fabricants de Cement0 de Esptia, Association of the Greek Cement Industry, Associacao T&nica da Indtistria do Cimento (Portugal), British Cement Association, Bundesverband der Deutschen Zementindustrie e.V., Cemhureau, FCdBration de I’Industrie Cimentitre (Belgium), Hydro Agri Benelux S.A., International Iron & Steel Institute, Irish Cement Ltd., Italcementi (Italy), S.A. des Ciments Luxembourgeois, Syndicat Fraqais de I’Industrie Cimentitre, and Vereniging Nederlandse Cementindustrie (The Netherlands). They are grateful to S. M. McNab for linguistic assistance.

REFERENCES

1. K. King and M. Munasinghe, “Global Warming: Key Issues for the Bank”, The World Bank, Environment Department, Divisional Working Paper No. 1992-36, Washington, DC (1992). 2. R. B. Howarth, L. Schipper, P. A. Duerr, and S. Strom, Energy Econ. 13, 135 (April 1991). 3. L. J. Nilsson, Energy-The International Journal 18, 309 (1993). 4. L. Schipper and S. Meyers, Energy Eftkiency and Human Activity, Past Trends and Future Prospects, Cambridge Univ. Press, Cambridge (1992). 5. T. MoroviC, G. Gerritse, G. Jaeckel, E. Jochem, W. Mannsbart, H. Poppke, and B. Witt, Energy Conservation Indicators II, Springer, Berlin (1989). 6. L. Schipper and D. V. Hawk, Energy Policy, 244 (April 1991). 7. E. Worrell, J. de Beer, and K. Blok, “Energy Conservation in the Iron and Steel Industry” in Energy Eficiency in Process Technology, P. A. Pilavachi, ed., Elsevier Applied Science, London (1993). 8. K. F. Langley, “Energy Use and Energy Efficiency in UK Manufacturing Industry up to the year 2000”, Vol. 1, Energy Efficiency Office, London ( 1984).

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“Energy Balances of OECD Countries”, 1987-1989, OECD, Paris ( 1990). “The Iron and Steel Industry in 1989”, OECD, Paris ( 1990). “Industrial Production, Quarterly Statistics 4/1990”, Eurostat, Brussels ( 1990). “Non ferrous metals & ferro-alloys production and related energy consumption in EC and EFTA member countries”, Eurometaux, Brussels ( 1992). 13. P. Crowson, Minerals Handbook 1990-1991, Stockton Press, New York, NY (1990). 14. “Panorama of EC Industry, Statistical Supplement 1992”, Eurostat, Brussels/Luxembourg ( 1992). 15. F. Springman, “Analysis of the Ecological Impact of Demonstration Projects in the Field of Rational Use of Energy-Development of Evaluation Criteria”, Part 3: Annexes, Regio-Tee GmbH, Stamberg, Germany (1991). 16. Data (originally of NITREX, Switzerland) provided by Hydro Agri Benelux S.A., Brussels. Belgium ( 1989). 17. “Chem-facts Ammonia”, Chemical Intelligence Services, Dunstable ( 1989). 18. “Energy, Yearly Statistics 1990”, Eurostat, Brussels/Luxembourg ( 1992). 19. “Chem-facts Ethylene & Propylene”, Chemical Intelligence Services, Dunstable ( 1991). 20. “Chem-facts Polyethylene”, Chemical Intelligence Services, Dunstable ( 1987). 21. “Chem-facts Polypropylene”, Chemical Intelligence Services, Dunstable ( 1988). 22. “The pulp and paper industry 1988”, OECD, Paris (1991). 23. “Cement Industry and Market Data: European Annual Review No. 12/1989-1990”, Cembureau, Brussels ( 1990). Cologne, 24. “Zement 92-93, Zahlen und Dater?’ (in German), Bundesverband der Deutschen Zementindustrie, Germany ( 1993). (20 July 1993). 25. Written communication from S.A. des Ciments Luxembourgeois, Esch-sur-Alzette 26. Written communication from R. Bouchat, Federation de l’lndustrie Cimentiere (Cement manufacturers’ Federation Belgium), Brussels (15 July 1993). ‘s Hertogenbosch, The 27. Personal communication from P. Lanser, Vereniging Nederlandse Cementindustrie, Netherlands (17 August 1993). 28. F. van Oostvoorn, P. Kroon, and A. V. M. de Lange, “SERUM: Een model van de Nederlandse raffnageindustrie” (in Dutch), Energy Study Centre, Petten, The Netherlands (1989). 29. A. Cantrell, “Worldwide Refining”, Oil Gas J. 85, 76 (1987). 30. H. Bakker and J. H. Bredee, “CO?, Emission in Refineries”, Comprimo Engineers & Contractors, Amsterdam (1991) 31. A. Komppa, “Paper and Energy: A Finnish View”, in Energy EfJiciency in Process Technology, P. A. Pilavachi, ed., Elsevier Applied Science, London (1993). 32. J. G. de Beer, E. Worrell, and K. Blok, “Energy Conservation on the Long Term, Case Study: Paper and Board industry”, Dept of Science, Technology & Society, Utrecht Univ. (1993). 33. The Lurgi Route to Ammonia, Lurgi GmbH., Frankfurt/Main, Germany (March 1987). 34. E. Worrell and K. Blok, Energy-The International Journal 19, 195 (1994). (in German), in Gesundes Wohnen, J. Becker& 3.5. K. Kroboth, “Zement Herstellung-Eigenschaften-Hydratation” ed., Beton Verlag, Dusseldorf, Germany (1986) (in German). 36. S. R. Venkateswaran and H. E. Lowitt, “The U.S. Cement Industry: An Energy Perspective”, Department of Energy, Washington, DC (May 1988). 37. H. Herschenbach and A. Wolter, “Auswahlkriterien fur den Einsatz des kurzen Zementdrehrohrofens” (in German), ZKG 35, 450 (1982). und Betriebsverhalten von Zementdrehofenanlagen mit Vorcalcini38. H. Roseman, “Brennstofenergieverbrauch erung” (in German), ZKG 40, 489 (1987). 39. E. Worrell, R. J. J. van Heijningen, J. F. M. de Castro, J. H. 0. Hazewinkel, J. G. de Beer, A. P. C. Faaij, and K. Vringer, Energy-The International Journal 19, 627 ( 1994). 40. “Steel Statistical Yearbook 1992”. International Iron and Steel Institute, Brussels (1992). 41. L. L. Teoh, Ironmaking Steelmaking 16, 303 (1989). 42. Personal communication from Mrs Frank, IEA, Paris (27 July, 1993). 43. Energy Statistics 196&1991 (diskette service), OECD/IEA, Paris (1993). 44. “Energy Supply in The Netherlands-Annual Figures 1988”, Netherlands Central Bureau of Statistics, The Hague, The Netherlands ( 1989). 45. Industrial structure Staristics 1988, OECD. Paris ( 1989). 46. K. Blok, A. J. M. van Wijk, E. Nieuwlaar, and W. C. Turkenburg, “Patronen in het industritle energieverbruik en de toepassing van warmte/krachtkoppeling” (in Dutch), Universiteit Utrecht (1985). 47. M. J. Mtiller, ed., Handbuch ausgewiihlter Klimastutionen der Erde (in German), 3rd edition, Universitlt Trier (1983). 48. Written communication from G. van Noord, KTI B.V., Zoetermeer, The Netherlands (25 July 1991). 49. “Statistics on Energy in the Steel Industry (1990 Update)“, International Iron and Steel Institute, Brussels (1990).