Economic aspects of crop selection for phytoremediation purpose and the production of biofuel. Prof dr. Bernard Vanheusden Ms.

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1 Economic aspects of crop selection for phytoremediation purpose and the production of biofuel Prof dr. Bernard Vanheusden Ms. Nele Witters OVAM, Mechelen, May 3rd 2011

2 Conceptual framework Crop Based Systems for Sustainable Risk Based Land Management for Economically Marginal Degraded Areas

3 Conceptual framework Rejuvenate I: Decision Support Tool (DST) Support the use of biomass on marginal land While recycling of organic matter Sustainability Greatest private benefits Greatest wider benefits (external) Manage risks Human health, environment Technology Acceptability

4 Conceptual framework Rejuvenate II Practical test of the DST Different work packages WP 3: site selection WP 4: SWOT WP 5: economic and legal aspects

5 Conceptual framework Source: Rejuvenate I WP 5

6 Work package 5 Research questions Does phytoremediation offer an economically viable alternative for conventional remediation technologies and which crops should be used and under what circumstances? Does phytoremediation result in other than private costs and benefits and if so are these externalities positive or negative?

7 Work package 5 Biomass on contaminated land Remediation duration Biomass production Income Biomass use Trace elements in biomass

8 Case study Campine region 700 km² (BE + NL), 280 km² (BE): Cd, Pb, and Zn Historical contamination Remediation from the moment contamination is serious until level where risk is restrained Accumulation of metals in crops Exceeding legal threshold values of food and fodder crops

9 Case study Two large scale experimental fields on a former maize field To evaluate the possibilities of cultivation of non-food crops as an economic alternative for farming on these historically contaminated soils Location: Flanders, Belgium (51 12'41"N; 5 14'32"E)

10 General model

11 Biomass on contaminated land Yield, remediation and income Biomass (ton dm ha -1 ) Cd (mg kg -1 dm) Cd removal (kg ha -1 y -1 ) Clean up time (y)* AGI ( ha -1 y -1 ) Maize ,260 Rapeseed ,023-1,354 Willow-twigs Willow-leaves Willow-total *To go from 2 to 1.2 mg kg -1 soil, calculations based on 25 cm soil depth for energy maize, rapeseed, and 50 cm willow, a soil density of 1.5 ton m -3, and assuming linear extrapolation

12 Biomass for energy

13 Biomass for energy Life Cycle Analysis (LCA) energy (NE) and CO 2 abatement potential of willow, energy maize, and rapeseed Direct energy use Indirect energy use (1 step) Transport Thermal and electric efficiency Rest products

14 Biomass for energy Trace elements: impact on energy production Biodiesel (literature) Combustion (literature, coal) Digestion (literature, batch + continuous) No impact on energy conversion efficiency No metals in energy carrier BUT legal restrictions on use rest product will have an impact on energy

15 Biomass for energy Energy production (1, in GJ ha -1 y -1 ) and CO 2 abatement (2, in kg CO 2 ha -1 y -1 ) Energy maize SRC (el) SRC (heat) SRC (CHP) Rapeseed (PPO) Rapeseed (diesel) EI (1) (13.4) (11.4) (11.4) (11.4) (14.0) (14.5) EI (2) (990) (841) (841) (841) (1,042) (1,081) EO (1) EO (2) 13,526 6,157 9,975 5,301 3,628 4,017 Epost (1) Epost (2) 1, NE (1) NE (2) 14,242 5,316 9,134 4,460 2,730 3,044 EI= energy input, EO= energy output, Epost= energy for rest product, NE= net energy

16 Trace elements in biomass Trace elements: impact on biomass class. Report on legal aspects Depends on main purpose of growing them Sustainable agricultural land use Remediation (no quantitative threshold value) Important for woody biomass Trace elements: impact on use rest product Report on legal aspects VLAREA, Directive 2002/32/EC, Fodder Decision Waste hierarchy: follow blind-folded? (WF Dir.)

17 Conclusion Does phytoremediation result in other than private costs and benefits and if so are these externalities positive or negative? (+) Renewable energy potential with CO 2 abatement (-)Contaminants in rest product

18 Conclusion Does phytoremediation offer an economically viable alternative for conventional remediation technologies and which crops should be used and under what circumstances? Case study: yes, serves as example Our findings do support the label of phytoremediation as a sustainable remediation technology BUT

19 Conclusion Does phytoremediation, as a multifunctional and sustainable alternative for conventional remediation technologies for functional restoration of contaminated soil, result in economically optimal remediation strategies?

20 Practical implementation? Data on more case studies available in 2012 within Rejuvenate. The opportunity to develop a practical generally applicable economic (and legal) decision framework for phytoextraction as an alternative technology for soil (and groundwater) management policy contribute to the introduction of phytoremediation on a commercial scale Contact: bernard.vanheusden@uhasselt.be (Law) nele.witters@uhasselt.be (Economics)