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226 Pages·2006·13.85 MB·English

by  Aina Svensson

Biomass Potential for Heat,
Electricity and Vehicle Fuel in Sweden

Volume I

Peter Hagström
Faculty of Natural Resources and Agricultural Sciences
Department of Bioenergy
Uppsala

Doctoral thesis
Swedish University ofAgricultural Sciences

Uppsala 2006
Acta Universitatis Agriculturae Sueciae
2006: 11

ISSN 1652-6880
ISBN 91-576-7060-9
© 2006 Peter Hagström, Uppsala
Tryck: Tierps Tryckeri AB, Tierp 2006
Abstract

Hagström, P. 2006. Biomass Potential for Heat, Electricity and Vehicle Fuel in Sweden.
Doctoral dissertation.

The main objective of this thesis was to determine how far a biomass quantity, equal to the
potential produced within the Swedish borders, could cover the present energy needs in
Sweden with respect to economic and ecological circumstances. Three scenarios were
studied where the available biomass was converted to heat, electricity and vehicle fuel.
Three different amounts of biomass supply were studied for each scenario: 1) potential
biomass amounts derived from forestry, non-forest land, forest industry and community; 2)
the same amounts as in Case 1, plus the potential biomass amounts derived from
agriculture; 3) the same amounts as in Case 1, plus 50% of the potential pulpwood quantity.
For evaluating the economic and ecological circumstances of using biomass in the
Swedish energy system, the scenarios were complemented with energy, cost and emergy
analysis.
The scenarios indicated that it may be possible to produce 170.2 PJ (47.3 TWh) per year
of electricity from the biomass amounts in Case 2. From the same amount of biomass, the
maximum annual production of hydrogen was 241.5 PJ (67.1 TWh) per year or 197.2 PJ
(54.8 TWh) per year of methanol.
The energy analysis showed that the ratio of energy output to energy input for large-scale
applications ranged from 1.9 at electric power generation by gasification of straw to 40 at
district heating generation by combustion of recovered wood. The cost of electricity at
gasification ranged from 7.95 to 22.58 €/GJ. The cost of vehicle work generated by using
hydrogen produced from forestry biomass in novel fuel cells was economically competitive
compared to today’s propulsion systems. However, the cost of vehicle work generated by
using methanol produced from forestry biomass in combustion engines was rather higher
compared to use of petrol in petrol engines.
The emergy analysis indicated that the only biomass assortment studied with a larger
emergy flow from the local environment, in relation to the emergy flow invested from
society after conversion, was fuel wood from non-forest land. However, even use of this
biomass assortment for production of heat, electricity or vehicle fuels had smaller yields of
emergy output in relation to emergy invested from society compared to alternative
conversion processes; thus, the net contribution of emergy generated to the economy was
smaller compared to these alternative conversion processes.

Key words: bioenergy potential, biomass potential, cost analysis, emergy, energy analysis,
energy scenarios, systems analysis, thermochemical conversion.

Author’s adress: Peter Hagström, Department of Bioenergy, SLU, P.O. Box 7061,
SE-750 07 UPPSALA, Sweden. E-mail: [email protected]

Contents

Volume I
1. Introduction, 7
Energy use, 9
Premises and dwellings, 9
District heating, 10
Industrial activities, 11
Mining and metal industry, 12
Saw milling industry, 12
Pulp and paper industry, 14
Transport, 14
Energy supply, 16
Biomass, 16
Round wood for residential heating, 17
Logging residues, 17
Charcoal, 17
By-products from saw mills, 17
By-products from pulp mills, 17
Energy crops from agriculture, 18
Peat, 18
Waste, 19
Fossil fuels, 19
Coal and coke, 19
Oil, 19
Natural gas, 20
Electricity, 20
Hydroelectric power, 20
Nuclear power, 20
Wind power, 21
Solar power, 22
Prerequisities for biomass in the future Swedish energy system, 22
Objectives and study design, 23

2. Methods, 27
Description of complex systems, 27
Evaluation methods, 28
Energy scenarios, 30
Energy analysis, 31
Cost analysis, 34
Emergy analysis, 35
Selected systems for the energy, cost and emergy analyses, 39
Data handling, 44

3. Biomass available for energy conversion, 45
Sources and supply systems, 45
Biomass from forestry and fuel wood from non-forest land, 46
Logging residues, 49
Final felling, 49
Thinning, 51
Trees from early thinning, 52
Direct fuel wood cuttings, 52
Fuel wood from industrial wood cuttings, 53
Fuel wood from non-forest land, 53
By-products from forest industries, 53
Agriculture, 56
Willow farming, 56
Reed canary grass, 59
Straw, 60
Municipal waste, 60
Recovered wood, 60
Other potential biomass assortments, 61

4. Selected biomass conversion systems, 65
Small-scale firing, 65
District heating, 67
Combined heat and power generation, 68
Electric power generation, 69
Vehicle fuel production, 71
Hydrogen production, 74
Methanol production, 75
Black liquor gasification, 77

5. Bioenergy in three scenarios, 79
Heat demand and supply in Sweden in 2002, 79
Energy use for heat production to premises and dwellings, 79
Single-family houses, 79
Premises and dwellings excluding single family-houses, 79
Energy use for heat production in industry, 81
District heating, 81
Scenario ‘heat’, 82
Single-family houses, 83
Premises and dwellings excluding single-family houses, 84
Energy use for heat production in industry, 85
District heating, 85
Compilation of biomass amounts required for heat production in scenario
‘heat’, 87
Simulation of the amounts of heat and electricity received, 88
Scenarios electricity and vehicle fuel, 89
Simulations of maximum amounts of electricity and vehicle fuel produced –
Case 1, 91
Simulations of maximum amounts of electricity and vehicle fuel produced –
Case 2, 93
Simulations of maximum amounts of vehicle fuel produced – Case 3, 96
The potential of electricity and vehicle fuel production by black liquor
gasification, 98
Comparison of maximum yields of energy carriers with today’s use, 102
Discussion, 103

6. Energy, cost and emergy analysis, 105
Prerequisites and methods, 105
Energy analysis, 106
Cost analysis, 107
Emergy analysis, 108
Results, 107
Energy analysis, 108
Cost analysis, 115
Emergy analysis, 118
Sensitivity analysis, 122
Discussion, 128

7. Summary and conclusions, 135
Comparisons of used methods and generated results, 135
Policy options, 144
Future work, 145
Conclusions, 145

References, 149

Acknowledgements, 173

Appendices
Appendix A: Abbreviations, units, symbols and time concepts, 175
Appendix B: Physical data, 180
Appendix C: Footnotes, 183
Appendix D: Description of the spreadsheet used for the simulations, 203
Appendix E: Brief of other technologies for gasification of biomass, 204
Appendix F: Calculation of sej/SEK index for 2002, 205
Appendix G: Dry matter losses, 213
Appendix H: Embodied energy and solar transformities of machinery
equipment, 217

Volume II
Appendix I: Tables A.I-1 through to A.I-17, 225
Appendix J: Data for silviculture, agriculture, machinery and process
equipment, 307

1. Introduction
Sweden is the fi fth largest of the European countries (449,964 square kilometres
(The Swedish Institute, 2002)). More than half of its land area is covered by forest.
Historically, forests have always been a major primary energy source in Sweden,
both for heating of dwellings in the rather cold climate and for industrial purposes
(Arpi (ed.), 1959).
Other natural resources forming the base for Sweden´s prosperity are rich metal
ores and plenty of rivers, in earlier times serving as a transport system as well as
a direct power source for fl our-mills and saw mills and also for pumps, bellows
and hammers in the mining and metal industry. Nowadays, the rivers have lost
their importance in the transport system and serve mainly as the basis for extensive
hydroelectric power production (Eklund, 1991).
With industrialisation process from the middle of the 19th century, Sweden had
about 3.5 million inhabitants of which 10% lived in urban areas. Since then, the
population has steadily increased and reached 5.1 million in 1900 and 9.0 million
people in 2004, with about 85% living in urban areas (see Figure 1-1).
Originally, wood was the dominant energy source, but coal gained importance
and accounted for 27% of the energy supply of 87 TWh iinn 11990000 ((LLHHVV == LLoowweerr
LLLHHHVVV
heating value). The coal was imported, as indigenous fossil fuel sources in Sweden
are limited and quite insignifi cant on a national level. A hundred years later the
population had increased by 75% (see Figure 1-1), and the energy supply was more
than fi ve times as high (or seven times as high if conversion losses in nuclear power
reactors are accounted for), and dominated by imported oil and uranium and to a
lesser degree indigenous hydroelectric power and biofuels.
Millionpeople
10
9
8
Totalpopulation
7
6
5
Ruralpopulation
4
3
Ruralpopulation
2 (newdefinition)
1
0
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
Figure 1-1. Population development in Sweden during the period 1900–2002. Total popula-
tion reached 9 million people in August 2004. Defi nitions of urban and rural changed in 1960.
Since then, Statistics Sweden defi ne urban areas as having at least 200 inhabitants living in
buildings normally not more than 200 meters apart from each other. Data from Statistics
Sweden (1999, 12-Aug-2004 (URL)).
7
The development of energy supply from 1900 to 2002 is shown in Figure 1-2,
details of the development of bioenergy seperated into different sources are pre-
sented in Figure 1-3. Energy supply and use in 2002 are displayed in Figure 1-4,
Windpower
TWh/year
Nuclearpower
700 -electricity
Hydropower -wastedheat
600
Naturalgas
500
Oil
400
Biomass
300 (mainlywood)
200
Coalandcoke
100
0
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
} }
Oilcrisis
WorldWarI WorldWarII
1973
Figure 1-2. Energy supply in Sweden during the period 1900–2002. Data on wood fuel
1900-1955 adapted from Arpi ((ed.) 1959); data on other energy supply 1900–1970 adapted
from yearly reports by Statistics Sweden; data 1970–2002 from the Swedish Energy Agency
(2003a, 2003b). The energy supply is based on lower heating values (LHV).
Districtheating
-municipalrefuse
-peat
TWh/year -woodfuels
-crudetalloil
100
90
Roundwood Biofuelsfor
80
forcharcoal Othersectors electricityproduction
70
Pulpandpaperindustry
60 -blackliquor
-otherby-products
50
40
Roundwoodforresidentialheating
30
20
By-productsfromsawmillingindustry
10
0
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
} } Oilcrisis
WorldWarI WorldWarII 1973
Figure 1-3. Biomass use for energy in different sectors of the Swedish economy during 1900–
2002. Data 1900–1955 from Arpi ((ed.) 1959, Table 43) showing average of fi ve year periods
adapted into TWh ppeerr yyeeaarr;; ddaattaa 11995566––11996699 aaddaapptteedd ffrroomm SSttaattiissttiiccaall YYeeaarrbbooookk ooff FFoorreessttrryy
LLLHHHVVV
published annually by the National Board of Forestry; data 1970–2002 from the Swedish
Energy Agency (2003a, 2003b).
8