Life Cycle Assessment of Organic Waste: Application and Relevance to New Zealand Simon Love

1. Life Cycle Assessment of Organic Waste: Application and Relevance to New ZealandSimon Love

2. PRESENTATION OUTLINE 1. Introduction to LCA 2. LCA and Organic Waste 3. Scion’s ‘Waste 2 Gold’ Project

3. Part One: Brief introduction to LCA

4. Introduction to LCA Life Cycle Assessment (LCA) is an analytical tool for the systematic and quantitative evaluation of the environmental impacts of a product or service system through all stages of its life.

5. ISO STANDARDS • ISO 14040 – ‘Principles and framework’ • Terms used • Phases of an LCA • Methodological framework • Need for critical reviews • ISO 14044 – ‘Requirements and guidelines’ • More detailed guidelines for each step • More specific requirements • Guidelines for critical reviews • Examples of application

6. Introduction to LCA Life Cycle Assessment Framework Direct applications: • Product development and improvement • Strategic planning • Public policy making • Marketing • Benchmarking • Ecolabels and product declarations Goal and scope definition Interpretation Inventory analysis Impact assessment

7. Impact Categories in LCA Input-related Categories • Abiotic resources (e.g. minerals, fossil fuels) • Biotic resources (e.g. fish, logs) • Land Output-related categories • Global warming • Depletion of stratospheric ozone • Human toxicological impacts • Ecotoxicological impacts • Photo-oxidant formation • Acidification • Eutrophication (incl. BOD and heat) • Odour • Noise • Radiation • Casualties Impact categories according to SETAC-EUROPE working group on LCA

8. Two types of LCA Consequential: • Consequences of future activities • i.e. What if we change a to z…? • Higher uncertainty • Decision support Attributional: • Attributing impact to current activities • i.e. ‘Footprint of process abc’ • Used for comparison and benchmarking

9. Notables in the Life Cycle Assessment scene Crown Research Institutes Consultants Universities Specialist Organisations Legislative and Government bodies

10. Part Two: LCA and Organic Waste

11. Challenges and Opportunities of Organic Waste Opportunities: • Energy Source • Conversion to useful products • Carbon-based • N & P - based • Land application • Large volume reduction Challenges: • Large volumes • Methane gas from decomposition • Odour • Leachate • Metals

12. New Zealand Waste figures • Total waste to landfill, year to June 2010: ~2.5 million tonnes1 • Organic waste at 23%: ~570,000 tonnes1 1. http://www.mfe.govt.nz/issues/waste/

13. Options for Organic Waste • A large proportion of organic waste in New Zealand goes to landfill • Other options: • Compost • Anaerobic digestion • Gasification • Pyrolysis • Incineration • Land application (biosolids)

14. LCA Studies • Can quantify important environmental impacts such as: • Global warming (methane production) • Energy (methane for heat/electricity, energy balance of incineration/drying/gasification) • Eutrophication (leachate to rivers/streams) • May not be as useful for impacts such as: • Accumulation of heavy metals (land application) • Odour

15. Can be combined with: • Economic (LCC): • Cost of processing • Useful byproducts • Energy production • Social factors • Not traditionally in LCA • Emerging field • Necessary to account for human factors!

16. Part Three: Scion’s ‘Waste to Gold’ Project

17. Wet Oxidation Technology • Feedstock: Biosolids from wastewater treatment • High pressure and temperature in oxidising environment • Outputs: Useful liquid products or energy, small amount of solids • Over 90% solids reduction

18. Bioenergy Liquid biofuels Biopolymers Waste to Gold High Carbon Solid Wastes Biomass Deconstruction Biodegradable Intermediates Energy Recovery Bioconversion

19. Economic and Other Potential Benefits • Reduction in solid waste to landfill, resulting in increased landfill life • Reduction of emissions from solid waste decomposition • Can produce a range of useful outputs (organic intermediates or energy)

20. RDC Case Study • Rotorua District Council were interested in wet oxidation of biosolids • LCA was employed for environmental comparison of current and future options

21. Options Compared • Current average NZ Landfill • Landfill without methane capture • Wet Oxidation (‘Waste 2 Gold’) variants • Anaerobic Digestion variants • Land Application

22. System Boundary Diagram Infrastructure Buildings

23. Results • W2G showed much promise in: • Global warming potential • Eutrophication potential • Solids Reduction • But had high energy and ozone depletion potentials • Sensitivity analysis shows that results are very sensitive to oxygen use and solids content, so much potential for improvement

24. Other Technologies • Anaerobic digestion • Good energy production • Reasonable solids reduction • Landfill • Landfill gas capture makes large difference • Still potential for eutrophication and acidification • Land application • Low energy alternative • Potential for heavy metals build-up • Application and transport could be a challenge • Public perception

25. RDC Case Study • Pilot scale plant currently being built • MfE Waste Management Fund : $1m

26. Conclusions & Future Work

27. Conclusions • LCA can help to decide on the suitability of future organic waste disposal options in NZ • Can provide quantitative and qualitative results in many impact categories • LCA assisted in putting case forward to gain WMF Funding for the Rotorua trial

28. Future Work • New Zealand-specific data collection and impact categories • Life Cycle Costing and Social LCA • Assessment of other new technologies