Biochar – What can if offer beyond the hype?

1. Biochar – What can if offer beyond the hype? Dr Simon Shackley Simon.shackley@ed.ac.uk UK Biochar Research Centre, University of Edinburgh www.biochar.org.uk Managing Sustainable Development Thursday 15th March 2012

2. Talk outline • Biochar as a potential win–win “wedge” in climate change - storing carbon and doing something useful with it …… but: • Does it add-up? • Life-cycle assessment • techno-economic evaluation • agronomy • Potential barriers / difficulties in implementation • regulatory issues and risks • Incentive mechanisms • state-of-knowledge • Implications & Conclusions

3. What is Biochar? ….. think of charcoal …….. “….. the porous carbonaceous solid produced by thermochemical conversion of organic materials in an oxygen depleted atmosphere which has physiochemical properties suitable for the safe and long-term storage of carbon in the environment and, potentially, soil improvement”.

4. Pyrolysed Wood Pellets

5. Biomass Conversion Pyrolysis Bio-liquids 1/3 Biomass Gases 1/3 1/3 Solid – biochar

6. Why Biochar?

7. Charcoal production: ancient but still common …….

10. Small and Large Pyrolysis in Japan

11. Use of rice husks in Ankur gasifier for syngas production with rice husk char by-product UKBRC Farm-scale pryolysis unit, East Lothian

12. UKBRC Pyrolysis Kiln (30kg/hr feed)

13. Carbon neutral versus carbon negative

14. Simple Carbon / Energy balance x

15. Soils and Agronomy • Nutrient content • pH (biochar typically alkaline) • Cation exchange capacity (CEC) • Water retention • Micro-organisms • Soil structure • Pollution reduction (nitrates) • Nitrous oxide and methane suppression?

16. Photo: Shackley & Cook, UKBRC 200 mm Biochar Images

18. Integrating biochar into top soil

19. Soil impacts • Ash pH is also alkaline so same benefit may occur • Alkalinity may also explain N2O suppression • Biochar appears to break-up into small particles (<50 μm) from physical weathering and abrasion • Properties likely to differ greatly from material incorporated at e.g. <2cm • Evidence for mineral-char interaction which may guard against char degradation

20. Angus – May 2010 Horticultural (carrots, potatoes, beets): (not sig) Fife – March 2010 spring barley (not sig) East Lothian – 2009 - spring barley (sig) 2010 - oil seed rape (not sig) 2011 – wheat (sig) Midlothian 2011 – spring barley (significant) Nottinghamshire – April 2010 - Spinach (no sig)

21. Yield Results from Stonelaws Farm, September, 2009 (barley) (all 10t/ha eqv)(courtesy of Jason Cook)

22. Overview of the Boghall trial • Spring Barley, 2011-2012 • 5 N-fertilisation rates • 2 biochar application rates • 3 replicates of each • Gases, soils, crops sampled. 10m courtesy of Jim Hammond

23. Crop Yields

24. ‘cradle – to - grave’ ‘seed – to – seed’ Measures environmental impacts of all stages Here we focus on energy and CO2 (equivalent) emissions (including N20 and CH4) Life – Cycle Assessment

25. Source of GHGs Source Sink of GHGs Key: Sink Variable Hammond, Shackley, Sohi & Brownsort (2011)

26. PBS carbon abatement in kg of CO2 equivalent per oven dry tonne of feedstock: 1 to 1.4 tCO2 per odt feedstock

27. The percentage contribution to carbon abatement from different life-cycle stages for virgin biomass feedstocks

28. Tonnes of CO2e abatement per hectare of land per year (assuming co-product allocation based on economic indicators)

29. Comparison with Other Bioenergy Options Expressed as CO2 abatement per oven dry tonne (odt) feedstock: Conventional bioenergy systems (combustion) in UK: emissions of 0.06 – 0.4 tCO2eq Per Odt Expressed as CO2 abatement per hectare Conventional bioenergy systems in UK: abatement of 1-7 tCO2eq per ha Most productive system (Brazilian bioethanol from sugarcane: 16 tCO2eq per Ha

30. Preliminary and provisional estimate of UK production of biochar per annum and carbon equivalent abatement per annum under three feedstock scenarios and resulting land-use implications (using virgin biomass feedstock-derived biochar only)

31. Biochar C abatement & feedstock quantities

32. How important is biochar? • Biochar could provide 1.5 – 10% of emissions reductions required in the UK by 2020 • Current global potential production = 0.6 +/- 0.1 GtC per year • If agri- and forestry wastes all used, this would constitute 1 to 1.8 GtC … probably achievable by 2050 - a carbon ‘wedge’

33. The role of biochar? • It is one of the very few technologies that can actually remove CO2 from the atmosphere • Carbon negative technologies needed because we are v. likely to exceed ‘safe’ concentration of CO2 in the atmosphere • Other options are: Bioenergy-CCS (BECCS), direct air-capture, permanent reforestation, etc.

34. The Costs of Pyrolysis-Biochar Systems

36. Figure Six: Biochar Marginal Abatement Cost (£tCO₂e-1) for higher feedstock supply scenario Marginal Carbon Abatement Cost Curve for pyrolysis-biochar 250 199 208 184 200 156 163 155 144 150 80 90 100 80 76 Cost (£) per tonne of CO2e Ø 57 50 19 18 0 volume (tCO2e) 0 2,000,000 4,000,000 6,000,000 8,000,000 10,000,000 12,000,000 -50 waste wood (L) Forestry residue (chips) Short rotation forestry (chips) ORS straw (M) Imported Canadian forestry (chips) Arboricultural arisings Miscanthus (chips) (L) SRC (chips) (L) Barley straw bales (S) Barley straw bales (L) Wheat straw bales(L) -100 -86 -86 Sawmill residues domestic organic waste (L) Sewage sludge (L) -150 -144 Commercial organic waste (L) S= small scale M= Medium scale L= Large scale OSR = Oil seed rape SRC = Short rotation coppice Values do not include indirect effects of biochars in soils on net CO₂equivalent abatement

37. Carbon Abatement Value • If biochar costs £100 per tonne, a carbon abatement price of £30-40 per tCO2 would be required for the operation to break-even (assuming no agronomic value) • ‘Front-runners’: Non-virgin resources:- where waste handling costs occur (gate fees, landfill tax) - e.g. green waste wood waste food waste sewage sludge • Virgin resources: arboricultural arisings low-cost straw (<£20 per t)

38. Valuing biochar in soil • Added soil benefit + C abatement benefits must exceed cost • Long term effects • soil structure and organic matter • nutrient use efficiency (CEC and soil solution) • Short and medium term effects • soil pH (liming effect) • ash nutrient value (extended release) • water dynamics • Aspects of cost • rate • frequency • method and timing

39. Potential Barriers: Regulation • EU Waste Framework Directive (WFD): biochar would, in some cases, be classified as a waste • Waste is: ‘any substance or object …which the holder discards or intends or is required to discard’. • Waste applications to land require a licence which can be expensive and time consuming to obtain. • There are waste categories that are exempted from the WFD but biochar is not one of these • If biochar becomes an established product, with a recognised market, it could (under the WFD) cease to be classified as a waste.

40. Regulation • Pyrolysis is a regulated process under Pollution Prevention Control (PPC) legislation • Health and safety / environmental nuisance issues could arise from dust particles, etc. • Wind and water erosion of biochar from application site • Metal contaminants • Polycyclic aromatic hydrocarbons (PAHs) – some are carcinogens, which may be produced during certain types of pyrolysis • Others: dioxins, phenols? • Nitrate vulnerable zones and N input controls (arising from N in the added biochar)

41. Incentive Mechanisms • Presently, there is no mechanism to obtain a carbon value from biochar • EU Emissions Trading Scheme – now includes CCS, but not carbon storage in soils • EU ETS only relevant to relatively large-scale power generation (>20MW) • Many PBS will be below this – hence not market players in the EU ETS in any case • Domestic market, Carbon Reduction Commitment (CRC) Energy Efficiency Scheme. Recently established as domestic carbon trading scheme for companies + organisations not included in the EU ETS – but off-setting is not permitted

42. Incentive Mechanisms • Flexibility Mechanisms under Kyoto Protocol - Clean Development Mechanism (CDM), Joint Implementation (JI) • CDM: Biochar not yet included. It will be tough to develop a robust methodology for its inclusion given current scientific uncertainties. • Voluntary Carbon Market (VCM): a biochar methodology has been submitted, but heavily criticised (for good reasons) • Biochar more likely to be registered through VCM in first instance, though methodological hurdles to overcome first.

43. How will biochar be deployed? • Seems unlikely that biochar will attract a market value for carbon abatement in the immediate future. • Even if it did, the current market price of CO2 is low – under EU ETS, CDM or VCM ($10-15). • Biochar deployment may, therefore, depend in the near future upon the agronomic value of biochar …... • And/or as an element in the environmental stewardship schemes • And upon the value of treating wastes through pyrolysis as opposed to alternative waste management (e.g. landfill, sewage sludge to land)

44. So can biochar add up? • What does it cost? • Producing biochar is generally not cheap unless waste feedstocks are utilised! • Front-runners are where feedstocks are low-cost or negative cost • What is it worth? • Biochar is valuable for carbon abatement, but no current mechanism for monetising this value • Biochar has uncertain benefits for soils / agronomy • Therefore, urgent need for including land-based carbon storage in C trading arrangements • But key scientific uncertainties have to be addressed first.