Agricultural residues for bioenergy

Transcription

1 Agricultural residues for bioenergy Niclas Scott Bentsen University of Copenhagen

2 Intended Learning Outcome Explain the basis of biomass supply, engineering processes and technologies involved, and energy production, in Sweden and Northern Europe. Identify the main elements of the production aspects of various forms of biomass, including forest and agricultural residues and biomass plantations. Supply, production, current use and utilization limitations, as well as the technologies related to production and conversion on a sustainable basis. Handle basic research tools concerning the estimation of current and future biomass supply and use, as well as the use of the different technologies associated with the planning, management, harvesting, transport, conversion and final use.

3 Bentsen, N. S., Felby, C., & Thorsen, B. J. (2014). Agricultural residue production and potentials for energy and materials services. Progress in energy and combustion science, 40, Bentsen, N. S., Nilsson, D., & Larsen, S. (2018). Agricultural residues for energy-a case study on the influence of resource availability, economy and policy on the use of straw for energy in Denmark and Sweden. Biomass and Bioenergy, 108, Bentsen, N. S., & Felby, C. (2012). Biomass for energy in the European Union-a review of bioenergy resource assessments. Biotechnology for biofuels, 5(1), 25.

4 Key words Resource potentials Agricultural residues/straw/stover/stalk Dry matter partitioning Resource mobilisation

5 What is a biomass potential?

6 What potential?

7 What potential? Theoretical limited by physical constraints only, photosynthetic efficiency, land/water surface, solar irradiation, Technical part of theoretical potential. Limited by technical constraints. Competing use, land availability, access, harvestability, Economic/market part of technical potential. Limited by economic constraints. Does it pay?, quotas, subsidies, tarifs, mandates, Implementation part of economic potential that can be mobilised within a fixed (short) timescale. Environmental/sustainable part of economic or technical potential that can be mobilised under constraints for biodiversity, soil degradation, water use, climate change,

8 Approach Batidzirai, B., et al. (2012). "Harmonising bioenergy resource potentials-methodological lessons from review of state of the art bioenergy potential assessments." Renewable & Sustainable Energy Reviews 16(9):

9 Straw as a biomass resource Central questions Department of Geosciences and Natural Resource Management How much is produced? The resource base, theoretical potential How much can be harvested? Availability, technical/economical/sustainable potential How much is already appropriated? Competition, availability, technical/economical/sustainable potential How can the resource be mobilised? Economic potential, policy framework, incentives, mandates

10 How much is produced - DK Kilo tonnes

11 How much is produced - DK Straw production is estimated from scalar expansion factors applied to crop production Department of Geosciences and Natural Resource Management

12 Is the residue to product ratio constant? Larsen, S. U., et al. (2012). "Straw yield and saccharification potential for ethanol in cereal species and wheat cultivars." Biomass and Bioenergy 45(0):

13 There are no/few official statistics on agricultural residue production, so how do we estimate residue potentials, when we only know the crop yield? Genus specific scalar multiplier: ATA (2008). Species specific scalar multiplier: Harberl et al (2010), Fujino et al. (1999), Smil (1999), Yamamoto et al. (1999), Kadam et al. (2003), Wirsenius et al. (2003), Ericsson et al. (2006), EEA (2006), Lal (2005), Hakala et al. (2009), Panoutsou et al. (2009). Geographically stratified species specific scalar multiplier: Krausmann et al. (2010). Species specific linear multiplier: Smeets et al. (2007), Fischer et al. (2010). Species specific piecewise linear multiplier: Bentsen et al. (2010). Species specific logarithmic multiplier: Scarlat et al. (2010). Department of Geosciences and Natural Resource Management Residue to product ratio applied Bentsen N. S. (2013) Biomass for bioenergy Biomass resources and their utilisation for energy services. University of Copenhagen

14 Plant physiology and matter partitioning Harvest Index Ratio between crop and total aboveground biomass Crop = grain, seed, fruit, tuber Residue to product ratio (RPR) Ratio between residue and product Product = crop Hay, R. K. M., & Gilbert, R. A. (2001). Variation in the harvest index of tropical maize: evaluation of recent evidence from Mexico and Malawi. Annals of Applied Biology, 138(1),

15 Plant physiology and matter partitioning Different targets of plant breeding Higher growth rate -> more biomass Shifted partitioning -> higher HI Hay, R. K., & Porter, J. R. (2006). The physiology of crop yield. Blackwell Publishing.

16 Straw - globally Experimental data supports the conjecture that RPR is exponentially related to crop yield. Bentsen, N. S., et al. (2014). "Agricultural residue production and potentials for energy and materials services." Progress in Energy and Combustion Science 40(0):

17 Straw resources - globally Department of Geosciences and Natural Resource Management Production from barley, maize, rice, soy bean, sugar cane and wheat 3,7 billion tons dry matter/year Estimated production from all crops 4,6 billion tons dry matter/year Teoretical potential, original estimat Bentsen, N. S., et al. (2014). "Agricultural residue production and potentials for energy and materials services." Progress in Energy and Combustion Science 40(0):

18 Straw resources - globally Department of Geosciences and Natural Resource Management Bentsen, N. S., et al. (2014). "Agricultural residue production and potentials for energy and materials services." Progress in Energy and Combustion Science 40(0):

19 How much can be harvested? but it also depends on location, soil, precipitation, temperature, soil fauna, crop rotation, livestock, Sustainable harvest rates are ALWAYS context specific. Scarlat, N., et al. (2010). "Assessment of the availability of agricultural crop residues in the European Union: Potential and limitations for bioenergy use." Waste Management 30(10):

20 How much is already appropriated? Not collected Bedding Feed/fodder Energy

21 Consumption (PJ) Department of Geosciences and Natural Resource Management How much is already appropriated? 30 Depends on who and how you ask Statistics Denmark 15 Danish Energy Agency Year

22 How much is appropriated? Scarlat, N., et al. (2010). "Assessment of the availability of agricultural crop residues in the European Union: Potential and limitations for bioenergy use." Waste Management 30(10):

23 How much is available for energy? Scarlat, N., et al. (2010). "Assessment of the availability of agricultural crop residues in the European Union: Potential and limitations for bioenergy use." Waste Management 30(10):

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25 Review of original estimates? Bentsen, N. S. and C. Felby (2012). "Biomass for energy in the European Union - a review of bioenergy resource assessments." Biotechnology for Biofuels 5.

26 European biomass potentials From 1990 to 2100 Large variation Energy crops seems to have a significant role in the future energy supply No unambiguous growth in agricultural residues and forest biomass Bentsen, N. S. and C. Felby (2012). "Biomass for energy in the European Union - a review of bioenergy resource assessments." Biotechnology for Biofuels 5.

27 Global potentials Department of Geosciences and Natural Resource Management

28 Harmonized resource estimates Harmonized potentials Energy crops EJ/yr Forest+agr residues+waste EJ/yr Total global sustainable potential EJ/yr Searle, S. and C. Malins (2014). "A reassessment of global bioenergy potential in 2050." GCB Bioenergy.

29 Summary on biomass resources The amount of biomass available is critical for economic and environmental evaluations/analysis of bioenergy systems. Actual knowledge of biomass resources is limited No common framework for resource assessment No common framework for availability assessments Biomass may be renewable, but is still a constrained resource Probably there is a huge biomass potential, but there is also a lot of competition No right answer to the question how much is there?

30 A practical mobilisation case Why is it that we use much more straw for energy in Denmark than in Sweden?

31 Climatic conditions are not that different

32 Agriculture is somewhat different Department of Geosciences and Natural Resource Management

33 Competition differs not so much

34 Policy targets match, policy instruments don t

35 Conclusions In a landscape perspective the density of straw resources in eastern Denmark is almost double that of Scania. Resource density has direct implications for logistics and transportation costs. Weather conditions seem to be more favourable for straw harvest in eastern Denmark than in Scania, although the difference is small. As a result of slightly better weather conditions, the straw-producing crops may ripen earlier in eastern Denmark than in Scania. The time window for harvest may also be slightly longer in eastern Denmark because of somewhat better in-field drying conditions.

36 Conclusions The organisational framework differs between Denmark and Sweden. Particularly large scale energy producers and the Danish Straw Suppliers Association have been instrumental in developing the straw to energy market, which is why the Danish market is well established, transparent and mature, while the Swedish is still developing. Policies and applied instruments differ between Denmark and Sweden although the overall goals of energy and climate policies are the same. Particularly the technology specific straw mandate in Denmark and the technology neutral green certificate system in Sweden are considered the main reason for the difference in straw use.

37 Mobilisation summary Mobilisation of biomass potentials does not happen automatically Requirements are Stable and favourable political framework Market Interested biomass producers Tradition Social license to operate

38 Intended Learning Outcome Explain the basis of biomass supply, engineering processes and technologies involved, and energy production, in Sweden and Northern Europe. Identify the main elements of the production aspects of various forms of biomass, including forest and agricultural residues and biomass plantations. Supply, production, current use and utilization limitations, as well as the technologies related to production and conversion on a sustainable basis. Handle basic research tools concerning the estimation of current and future biomass supply and use, as well as the use of the different technologies associated with the planning, management, harvesting, transport, conversion and final use.

39 Thank you for your attention