Waste-to-Materials:
Carbon recycling into built
infrastrucure
• KEVIN GARDNER
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DR. PHILIP NUSS
DR. STEFAN BRINGEZU
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*ENVIRONMENTAL RESEARCH GROUP, UNIVERSITY OF NEW HAMPSHIRE
**WUPPERTAL INSTITUTE FOR CLIMATE, ENVIRONMENT AND ENERGY
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Introduction
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 Pre-industrial era
 Forest clearing
 Use of biomass for food, materials, and energy
 Industrial era
 Use of fossil-fuels; relieved overall demand for fuel wood
 Shift towards renewables
 Currently, orientation towards increased use of biomass
 Bioenergy thought to be among the solutions for reducing
dependence on fossil fuels, switching to renewables and
mitigating climate change
 May only be fulfilled through expansion of global arable land.
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Introduction
 Have all of our efforts at reuse and recycling
resulted in lower materials consumption?
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Let's remind ourselves of the reality of our
recycling/efficiency gains!
And be realistic about our impact in our technical
world.
How is our work improving equitable access to
materials& energy?
 Still more than 90% of biomass and raw
materials are wasted on the way to making
products for market.
 Jevon's Paradox / Rebound effect needs to be
considered from a societal perspective.
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Sustainable Biomass Use
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•UNEP Resource Panel recommendations:
Bringezu et al. (2009)
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Socio-industrial metabolism: Future Features
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• Significant C in building and construction materials
• Construction/demolition debris & carbon fraction of MSW
should be looked at with view of cascading use.
• Capture carbon in waste materials by production of new
materials - keep C in the technosphere.
• C released at end of life through energy recovery.
Bringezu & Bleischwitz (2009)
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Carbon Recycling
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Source: P Nuss, (2012)
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Central Research Question
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 What are system-wide environmental burdens (and costs) of
thermo- and biochemical routes that would allow carbon recovery
from organic waste (i.e. BMSW, C&D wood, forest residuals) for
chemical feedstock provision?
 Comparison to conventional fossil-based production routes and
current WM practices (i.e. landfilling and incineration w/ energy
recovery)?
 GOAL: Provide information on environmental benefits
and tradeoffs prior to implementation
identify critical areas for improvement/focus
avoid burden shifting
provide systems perspective on prospects for
cascading use of carbon in technosphere
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Projects
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THERMOCHEMICAL
Fischer-Tropsch Synthesis
BMSW
Ethylene
BIOCHEMCIAL
Fermentation
Softwood Hemicellulose
Polyitaconic Acid (PIA)
THERMOCHEMICAL
Plasma Gasification
C&D Wood, Forest
Residuals
Syngas/Electricity
THERMOCHEMICAL
Carbon Recycling Review
BMSW
Polyethylene (HDPE)
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Projects
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THERMOCHEMICAL
Fischer-Tropsch Synthesis
BMSW
Ethylene
BIOCHEMCIAL
Fermentation
Softwood Hemicellulose
Polyitaconic Acid (PIA)
THERMOCHEMICAL
Plasma Gasification
C&D Wood, Forest
Residuals
Syngas/Electricity
THERMOCHEMICAL
Carbon Recycling Review
BMSW
Polyethylene (HDPE)
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Fischer-Tropsch Synthesis - production of base chemical for durable
goods production
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 Goal & Scope
 What are the life-cycle environmental burdens associated
with the production of ethylene in comparison to its fossilbased counterpart and when compared to conventional
waste management practices?
 The functional unit for comparison is 1 kg ethylene at the
factory gate.
 Inventory data from literature search, LCI databases,
personal communications.
 Geographical area: USA
 Impact Categories: GWP, CED, TMR, AP, Smog, WD
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Gasifier Technologies
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LCA - Comparative Systems
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Global Warming Potential (GWP)
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Impacts
Offsets
BAU#1 (LF) Business-as-Usual – Landfilling
BAU#2 (INC) Business-as-Usual – Incineration
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Global Warming Potential (GWP)
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BMSW - FT-liquids LHV eff.
Battelle 27%
MTCI: 31%
Choren: 53%
Impacts
Offsets
BAU#1 (LF) Business-as-Usual – Landfilling
BAU#2 (INC) Business-as-Usual – Incineration
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functional unit:
ethylene (not
management
of waste)
Global Warming Potential
(GWP)
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BMSW - FT-liquids LHV eff.
Battelle 27%
MTCI: 31%
Choren: 53%
BAU#1 (LF) Business-as-Usual – Landfilling
BAU#2 (INC) Business-as-Usual – Incineration
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Sensitivity Analysis
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 Allocation
 Economic vs. physical
 Energy substitution
 Marginal power mix
 Future power mix (BLUEMap)
 Conversion efficiencies
 ~50% in future design
 Energy inputs to steam cracker
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Sensitivity Analysis
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Incineration
Landfilling
C-Recycling
 Energy Substitution
 Marginal (100% coal), 1.31kg CO2-eq/kWh
 Future (BLUEMap), 0.21kg CO2-eq/kWh
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Sensitivity Analysis
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 Conversion Efficiency (from BMSW to FT-liquids)
 Assuming 50% LHV eff. in future design
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Sensitivity Analysis
 Conversion Efficiency (from BMSW to FT-liquids)
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Cost Analysis: Fischer-Tropsch Synthesis
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 Capital cost
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CRF=10.19% (m=20 years, r=8%)
8395 hours/year
15%/25% project contingency
 O&M cost
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Material and energy costs / revenues
US$ 2.06 for the Battelle and US$ 1.85 for the
MTCI system (Jan 2011 US$).
US$ 1.17 per kg fossil-based ethylene (CMAI 2011).
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Cost Analysis: Fischer-Tropsch Synthesis
tipping fee: $30/ton
discount rate: 8%
FT-diesel: $.99/kg
propylene: $1.57/kg
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Dissertation Projects: FTS
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Take-home
messages:
Take
home message(s)
• Carbon recycling may have lower impacts than
landfilling BAU
• But: higher than incineration BAU
• Might become increasingly competitive in the
future
• Production cost not yet competitive (may break
even w/ fossil-based counterpart at BMSW
tipping fee of $42)
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Conclusion
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 Production
of clean synthesis gas, fermentable
carbohydrates and subsequent energy/chemical feedstock
possible
 While as of yet conversion technologies do not work in
integrated fashion (future vision), results may give guidance
on benefits and tradeoffs prior to implementation
 Contributions:
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Identification of potential routes suitable for carbon recycling
Detailed environmental assessments and inventory data that may be used
in future studies
Identification of sources of large uncertainties and ‘hot-spots’
Recommendations for improvements
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Limitations and Future Work
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 Limitations of attributional LCA calls for
advanced sustainability assessment in future
work
 e.g. Consequential LCA
 Additional carbon recycling routes (e.g. MTO)
 Policy analysis (barriers to implementation)
 Forest growth carbon dynamics (for systems
using forest residuals as feedstock)
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Thank You
[email protected]
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