Basics of biomass production Biomass and bioenergy potential Solid biomass Extra: Land-use changes (LUC and ILUC see supplementary material)

Lecture 10 Biomass •  Basics of biomass production •  Biomass and bioenergy potential •  Solid biomass •  Extra: Land-use changes (LUC and ILUC see s...
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Lecture 10

Biomass •  Basics of biomass production •  Biomass and bioenergy potential •  Solid biomass •  Extra: Land-use changes (LUC and ILUC see supplementary material)

C6370 Peter Lund 2014

Bioenergy in short •  What is biomass and bioenergy ? –  All forms of organic material (forests, plants, crops, algae, forestry and municipal waste, garbage, manure, etc.) is biomass; terrestrial (3/4) and ocean biomasses –  Often biomass and waste Alows are handled separately (e.g. in bioenergy statistics) –  Biomass is converted into bioenergy: •  Thermal, chemical and biochemical conversion processes •  Solid, liquid and gaseous bioenergy/fuels •  Bioenergy from biomass waste streams or from virgin biomass

•  Role of bioenergy in energy production –  Finland >20%, world 6% (14%), EU 4% of all energy (10% of all fuels in 2020)

•  Future of bioenergy –  Key issue is production of sustainable biomass resources –  Different advanced conversion paths: bio CHP, anaerobic fermentation, gasiAication, waste, biofuels, energy crops, lignocellulosic biofuels C6370 Peter Lund 2014

Relative share of bioenergy forms in EU presently

Evolution and nature’s energy systems Energy process Energy cocktail!

DNA cell/bacteria (fermentation)

plants/animals

mammals

Carbon stores

CO2

anaerobic assimilation / cyanobact. aerobic assimilation

Waste

Oxygen in atmosphere

O2 ↓

CO2

Ilmakehän happipitoisuus

Life form

korkeat elämän muodot

0.01

yhteyttäminen

0.001 0.0001

3

2

1

aika, mrd vuotta, nykyhetki=0

C6370 Peter Lund 2014

0.1

kasvit/hengitys

4

human

1

nykytaso, 21% happea

0

Natural production of biomass light

–  Photosynthesis 6 CO2+6H20 → C6H12O6+6O2; glucose as end product –  Light absorbs in chlorophyll which is located in chloroplast (cell) –  Conversion efAiciency of photosynthesis process from light to energy η(max) •  •  •  • 

Wavelength response (400-700 nm) ReAlection losses (20%) Quantum efAiciency (8 photons/Aixation) Plants own use (metabolisim)

50% 80% 28% 60%

Total (max) 6.7% –  C4-plants (4-C sugar as Airst product; sugars and starch, corn), theoretical η= 6.7% –  C3-plants (trees, wheat) η=3.3% (light saturation, only 30% of light utilized) ; 95% of all plant biomass –  Practical efAiciency of C4 plants is 2-3%

C6370 Peter Lund 2014

C3 and C4 processes to fix carbon dioxide and produce biomass •  The C3 pathway requires 18 ATP for the synthesis of one molecule of glucose while the C4 pathway requires 30 ATP •  C4 has four carbon atoms in the intermediate compound and is more advanced than C3 (Calvin cycle, picture below)

C6370 Peter Lund 2014

Biomass productivity of different ecosystems Producer

Biomass productivity (gC/m²/yr)

SWAMPS AND MARSHES

2,500

CORAL REEFS TROPICAL RAIN FORESTS ALGAL BEDS RIVER ESTUARIES

2,000

8

16

2,000

0.28

0.56

TEMPERATE FORESTS

1,250

19

24

650 140 125 3

17

11

311 50

39 0.15

CULTIVATED LANDS TUNDRAS OPEN OCEAN DESERTS

Total production (billion tonnes C/ yr)

2,000 1,800

Peter Lund 2013 Source Wikipedia

Total area (million km²)

Amount of biomass produced through photosynthesis •  World-wide biomass production is around 220 billion tons, or ten-fold world’s energy demand; 20% of this is used as food for land (animals) –  Total photosynthetic productivity of Earth is much higher or 1500-2250 TW –  Amount of biomass of bacteria ~ Amount of biomass of plants –  Biomass is an important carbon binder (110 billion tons of C/yr), it’s use inAluences climate-change

•  Energy value of biomass: in average 17-18 GJ/ton (dry mass; water content of fresh biomass may be quite high, 40-90%); woody biomass 20 GJ/ton •  Yields (incl water) : C4-plants 150 ton/yr per ha, C3-plants 70 ton/yr, but sensitive to temperature and amount of light, much lower values in north –  Mid-west USA 208 ton/yr per ha (C4)

–  Utilization: ½ of the biomass can be utilized (exl. roots, stump, branches → max 30-35 ton/year per ha C6370 Peter Lund 2014

Sunshine, water and heat = biomass •  Optimal temperature for biomass growth is 20-30 oC, if < 0-5 oC no production •  Water demand is 300-1000 ton H2O/1ton dry mass (C4 more effective) •  Solar radiation in tropics 5-6 GJ/ m2 yr, in north less than ½; biomass production is ca 1,5 g drymass per 1 MJ of solar radiation •  CO2 increases growth (in particular C3) C6370 Peter Lund 2014

Effect of solar radiation on growth (C3) •  Saturation may occur already at 100 W/m2 (max solar is 1000 W/m2)

C6370 Peter Lund 2014

Net dry matter production

C6370 Peter Lund 2014

Biomass productivity of different ecosystems Producer

Biomass productivity (gC/m²/yr)

Total area (million km²)

Total production (billion tonnes C/ yr)

swamps and marshes

2,500

tropical rain forests

2,000

8

16

coral reefs algal beds river estuaries

2,000 2,000 1,800

0.28

0.56

temperate forests

1,250

19

24

650 140 125 3

17

11

311 50

39 0.15

cultivated lands tundras open ocean deserts Source Wikipedia

C6370 Peter Lund 2014

Energy yields from crops

C6370 Peter Lund 2014

Sources of solid biomass •  Waste streams from food production and forestry industries correspond to 20-25% of world energy •  All that waste cannot be utilized: –  Too dispersed, too low quality –  Other economic use –  Recycling (fertilizers)

•  ½ of all roundwood goes to industrial use, ½ to energy and charcoal –  Using natural forests as such for energy may be questionable

•  Energy plantations –  Short circulation plants –  Yearly (grasses) and 3-5 year-periodicaly harvested (trees) plants –  Sorgum, perennials, poppel, ruokohelpi

C6370 Peter Lund 2014

Sources of biowaste Waste sources (EJ)

14-17 GJ/ton C6370 Peter Lund 2014

Energy balance of biomass plantations

•  Net energy is deAined as energy contents of produced biomass divided by energy needed to produce that biomass •  Net energy ratio above 10 is possible

C6370 Peter Lund 2014

Potential of solid biomass in world energy production •  Overall potential of waste streams is around 10% of world energy •  Energy plantations: –  assume 15 ton/ha per year –  2050: potential could 60-70% of world energy (260 EJ/yr, corresponds to 10% of useful land)

C6370 Peter Lund 2014

Biomass in Europe •  Bioenergy corresponds to 4% of EU’s primary energy, potential of own biomass sources is 15% •  Environmental constraints put limitation to use

source: EEA C6370 Peter Lund 2014

Where does biomass come from in EU? •  Biomass from waste and agricultural residuals have largest potential

source: EEA C6370 Peter Lund 2014

Summary of differerent biomass potential estimates by 2050 •  •  •  •  •  •  • 

Residues from agriculture Organic waste Dung Forestry waste Energy crops Energiaplantations (poor land) Biomaterials

•  Total



15-70 EJ 5-50 5-55à0 30-150 à0 0-700 (100-300) 60-150à0 40-150





40-1100 EJ





(250-500 EJ )



•  World energy use presently ~ 450 EJ

C6370 Peter Lund 2014

Sustainable biomass potential •  30% of present energy use

C6370 Peter Lund 2014

Finland’s biomass resource base •  Huge biomass resource base: wood 50, agriculture 8, waste 5 Mton/yr, peat reserves total 2060 Mtons •  Wood grows 100 Mm3/year, 900 PJ/yr; total energy use 1400 PJ •  Energy crop yields would be 4-5 t /ha per year

C6370 Peter Lund 2014

Biomass energy use in Finland and potential

•  Bioenergy use at present in Finland 310 PJ (22%), peat 100 PJ

C6370 Peter Lund 2014

Indirect and direct land-use changes •  LUC and ILUC

C6370 Peter Lund 2014

Indirect and direct land-use changes •  aa

C6370 Peter Lund 2014

Your Work # 10 •  Home work from Lecture 10 (Biomass) –  How much could/should Finland increase its renewable energy use through biomass resources?

•  In preparing for Lecture 11 (Bioenergy) –  Have a look on the biofuel stuff, just overview)

C6370 Peter Lund 2014

Extras

C6370 Peter Lund 2014

Photosynthesis on molecular level (basis for 4th generation biofuels)

•  Microalgae and cyanobacteria show several energy reaction mechanisms : •  Basic photosynthesis reaction: CO2+H20 + light→ CnHmOn+O2 •  Anaerobic conditions: 4H20 + hydrogenase entzyme (side product of photosynthesis, sensitive to O2) + light → 2O2 + 4H2; •  Cyanobacteria and nitrogenase entzyme: – 

N2 +8H++8e-+16ATP → 2NH3+16ADP+16Pi+ H2

•  Purple bacteria –  From organic material or H2S electrons à proton gradient (H+) à ATP (energy storage that drive charge transfer mechanisms) C6370 Peter Lund 2014

Purple bacteria

Application: Biohydrogen from microbes Thermophylic bacteria that operate at temperatures up to 70°C give higher yields than bacteria that operate at ambient temperatures. A typical chemical reaction is: C6H12O6 + 2H2O = 2CO2 + 2CH3COOH + 4H2 The yields can be increased further by using phototropic bacteria that convert acetic acid to hydrogen, as follows: CH3COOH + 4H2O = 2CO2 + 4H2

C6370 Peter Lund 2014

Photobiochemical efficiency in bioH2 •  Bacteria can be used to produce fuel or chemicals (see previous slide) •  Yield of biological H2 120 l/ha/day in southern Europe, in north half of this •  In future photobioreactors

C6370 Peter Lund 2014