Seeking Synergy Between Technological and Ecological...

Seeking Synergy Between Technological and Ecological Systems for Sustainable Engineering

Bhavik R. Bakshi

William G. Lowrie Department of Chemical & Biomolecular Engineering

The Ohio State University, Columbus, OH 43210

Department of Chemical Engineering,Carnegie Mellon University, March 26, 2013

Ecosystems and Sustainability

� Availability of ecosystem goods and services (Natural Capital) is essential for sustainability

� It is the source of all other goods and services

� But its role is greatly underappreciated

EconomicProducts &ServicesEconomy

NaturalCapital

Ecosystem

Sun

Drawing Down Natural CapitalRegulating

• Air quality regulation

• Regional and local climate regulation

• Erosion regulation

• Water purification

• Pest regulation

Provisioning

• Capture fisheries

• Wild foods

• Wood fuel

• Genetic resources

Cultural

• Spiritual & religious values

• Aesthetic values

DegradedDegraded

• Pest regulation

• Pollination

• Natural hazard regulation

resources

• Biochemicals

• Fresh water

MixedMixed

EnhancedEnhanced

• Timber

• Fiber

• Water regulation (e.g., flood protection)

• Disease regulation

• Recreation & ecotourism

• Crops• Livestock• Aquaculture

• Carbon sequestration

Anthropogenic Impacts & Ecological Limits

Climate Change

Atmospheric AerosolLoading

Chemical PollutionOcean Acidification

Stratospheric Ozone Depletion

Rockstrom et al., Nature, 2009; http://vimeo.com/anthropocene/shortfilm

Nitrogen cycle

Biodiversity Loss

Depletion

Phosphorous cycle

Global Freshwater UseChange in Land Use

Typical Engineering Response

� Develop new technologies

� Fuels and materials from biomass

� Enhanced oil recovery, fracking

� Genetically engineered crops

� Enhance efficiency

� Process systems engineering has played a key role� Process systems engineering has played a key role

� From process to enterprise scales

� May not solve the problem, but shift it outside the analysis boundary

“The significant problems we face cannot be solved at the

same level of thinking we were at when we created them”

- Albert Einstein

Ecosystem

Economy

Value ChainIncreasing

system scope

and complexity

Increasing

relevance to

global sustainabilityEnterprise

From PSE to Sustainable Engineering

Domain of Process Systems Engineering

Process

Process &

Prepare

Inputs

Fabricate

& Package

Product

Distribute

& Support

Product

Extract

Raw

Materials

Recover,

Recycle or

Dispose

Flows &

Services

Flows &

Impacts

Bakshi, B. R., and J. Fiksel,

AIChE J., 2003

Challenges in Sustainable Engineering

� Consider network of processes across scales

� Choose more “eco-efficient” alternative

Life Cycle Assessment


� Aims to consider all processes from “cradle to grave”

� Need data for each stage of life cycle

Production

Extraction

& Processing

Energy Emission

Environment

life cycle

� Energy

� Materials

� Emissions

� Popular and standardized

Use

Disposal

Reuse or

recycleMaterial

Waste

Waste Emission

Carbon Footprint of Selected Biofuels

8E+12

1E+13

1.2E+13

1.4E+13

GasolineDiesel

15

-2E+12

0

2E+12

4E+12

6E+12

CornEthanol

CornStover

YellowPoplar

News-print

Switch-grass

MSW

Life Cycle Approaches in Industry

� “Sustainability Nears a Tipping Point”

� Survey of 4000 managers from 113 countries

� MIT Sloan Management Review (Jan 23, 2012)




� Account for role of ecosystem services

� Quantify contribution from nature to human activities



Ecologically-Based Life Cycle Assessment

Eco-LCA Network Model

Zhang, Baral, Bakshi, Env. Sci. Tech., 2010

Framework for Eco-LCA

Equations for Eco-LCA

� Intensity of resource use in each sector,

R = (I – AT)-1X-1vph

aij=zij/xj

� Life cycle resource use for final demand, fnew

vph,new = RTfnew

� Life cycle network analysis,

^

� Life cycle network analysis,

(I – A)-1 = I + A + A2 + A3 + …

� Hybrid Eco-LCA can combine detailed process level information with economy scale model

Direct Indirect

Eco-LCA softwarehttp://resilience.osu.edu/ecolca/

Nitrogen footprint

1.50E+11

2.00E+11

2.50E+11CornEthanol

CornStover

Switch-grass

-2E+12

0

2E+12

4E+12

6E+12

8E+12

1E+13

1.2E+13

1.4E+13

Carbon Footprint

0.00E+00

5.00E+10

1.00E+11

1.50E+11

Gasoline

Diesel

Stover

YellowPoplar

News-print

grass

MSW

Ecosystem Services in Eco-LCA

� PROVISIONING SERVICES

� Fuels

� Crude Oil; Natural gas; Coal; Nuclear fuel

� Ores

� Iron; Copper; Silver; Zinc and lead; Gold; Other metallic ores

� Primary production

� Fish & related species

� Wood

� Grass

� Land

� Cropland; Rangeland and pasture; Timber

� Pollination

� Sunlight

� Hydropotential

� Geothermal

� Wind

� Non-metallic

� Minerals; Crushed stone; Sand

� Water

� Irrigation water

� Thermoelectric power generation water

� Public Supply Water

� SUPPORTING SERVICES

� Mineralization

� Nitrogen, Phosphorus

� Soil

� Nitrogen deposition from atmosphere; Detrital matter; erosion

� Farm, Timber, Ranch

* Work In Progress

Ecosystem Services in Eco-LCA

� REGULATING SERVICES

� Carbon Sequestration

� Yard trimming and food scrap stocks in landfills

� Urban trees

� Soil (land converted to grassland)

� Soil (cropland remaining cropland)

� Forest

� Water Regulation*

� Climate Regulation*

� Disease Regulation*

� Pest Regulation*

� Waste treatment*

� EMISSIONS

� Carbon dioxide

� Fuel combustion� Forest

� Ranchland

� Farmland

� Ocean*

� Reactive Nitrogen Production

� Fixed by microorganisms in soil

� From leguminous plants

� Atmospheric deposition

� Livestock manure

� Fertilizer use (farm and non-farm)

Fuel combustion

� Grassland remaining grassland

� Land converted to cropland

� Urea fertilization

� Liming

� Reactive Nitrogen

� Soil management

� Forest fires

� Burning of agricultural residues

� Manure management

� Many other pollutants

* Work In Progress

Thermodynamic Aggregation

� Aggregation reduces dimensionality

� Why thermodynamics?

� Governs the behavior of all systems

� Exergy (available energy) is the ultimate limitingresource

++−∆= zgv

STHB2

� Provides common currency for the joint analysis of industrial and ecological systems

� Can represent energy and material resources

� Monetary aggregation ignores role of nature

++−∆= zg

vSTHB

20

Eco-LCA Thermodynamic Indices

NNon-Ren

Resources

Sun EcosystemR1 Industrial

Processes

F

Y Economic

Resources

R

� Renewability Index

� R/(F+N+R)

� Return on Investment (Quality Corrected)

� Product Exergy / Processing Exergy = EY/F

W

Wastes

R2

(Odum, 1996; Brown and Ulgiati, 1998; Baral and Bakshi, 2010)

Fuels: Renewability vs. Physical ROI

� Best fuels have high renewability and high ROI

� Bubble area represents fuel use or potential

� �

Renewability

Quality corrected return on investment

Shortcomings of Life Cycle Methods

� Life cycle methods enhance efficiency at large scale

� Focus is on doing “less bad” … not good enough!

� Continuous improvement maintains status quo, does not foster breakthrough innovation

� Ignores capacity of ecosystems to provide services� Ignores capacity of ecosystems to provide services

� Could lead to perverse decisions that increase reliance on degraded ecosystem services

� Cannot benefit from ability of ecosystems to meet industrial and societal needs




� Account for role of ecosystem services




� Account for capacity of ecosystems to provide services

� Exploit synergies between technological and ecological systems to benefit both

Ecologically-Based Life Cycle Assessment

Techno-Ecological Synergy (Eco-Synergy)

Goods and Services from Ecosystems

N, P

Solvents

Pesticides

Sewage

Aromatics Fresh Water

Genetic Resources

WetlandFish, Rice

Flood Regulation

CO2Biomass

Particulate Matter

NOx

CO2

SO2

COO3

O2

Trees & Soil

Pollinators

Fuel

Aesthetics

Recreation

Task Technologicalsystem

Ecological system

Water purification Water treatment Wetland

Air purification Scrubber, precipitator Trees

Carbon sequestration Deep well injection Trees, soil, wetlands

Water provision Dams, canals Forest, aquifers,

Technological vs. Ecological Options

Water provision Dams, canals Forest, aquifers, rivers

Shoreline protection Sea walls Mangroves

Reliable power & flood control

Sediment dredging Forests on slopes upstream of dam

Pollination None Bees, bats, birds

� Are ecological solutions practical and economically feasible?

Renewability vs. ROI with Eco-Synergy

Low Intensity High Diversity grassland• Natural prairie• On degraded farmland

Percent Re

Return on emergy investment

ISSST

Modified Corn• No till• Wetlands• Crop rotation

Eco-Synergy for Biodiesel Production

Conventional Biodiesel Facility

� Eco-efficiency approach will enhance techno-logies to reduce impact

� Ignores local ecosystems

0.4

0.6

0.8

1

1.2

NOx

SOxCO2

0

0.2

0.4 SOx

PM10CO

CO2

Demand for Ecosystem Services

Eco-Synergy for Biodiesel Production

Biodiesel Facility with Eco-Synergy

� Local ecosystems can supply needed ecosystem services

� Highly cost effective & “island of sustainability”

0.4

0.6

0.8

1

1.2

NOx

SOxCO2

0

0.2

0.4 SOx

PM10CO

CO2

Supply of Ecosystem Services with Eco-Synergy

Demand for Ecosystem Services

Columbus Biosolids – Current Approach

� Biosolids coming from two wastewater treatment facilities: Southerly & Jackson Pike

� Allocation between

� Incineration, Landfill, Composting, Land Application

� Minimize cost and carbon dioxide emissions

City of ColumbusWWTP Biosolids

Production

Gravity ThickeningDewatering

Anaerobic Digestion

Decision:How toallocate

biosolids?

Incineration

Landfill

CompostProcess

LandApplication

Ash

LandfillGas

Compost

Fertilizer

10

11

12

Tota

l C

ost

(m

illion

s o

f d

olla

rs)

Base Case

Process Optimization [Sikdar, 2008]

SI - 50%

SL - 5%

SC - 45%

JLA - 9%

JI - 91%

Current Operation

Total CostMillion $

Traditional Engineering Solution

6

7

8

9

0 5000 10000 15000 20000 25000 30000 35000 40000 45000

Tota

l C

ost

(m

illion

s o

f d

olla

rs)

Net GHG Released (tons CO2 equiv)

SI - 100%

JLA - 100%

SI - 41%

SC - 59%

JLA - 100%

SL - 41%

SC - 59%

JLA - 100%

Pareto Curve – no ES or tax

Pareto Curve –no ES,with tax

Designs in this region are not reachable by technological network

Net GHG Released (tons CO2 equivalent)

Biosolids Eco-Synergy

City of ColumbusWWTP Biosolids

Production

Gravity Thickening

Dewatering

Anaerobic Digestion

Decision:How toallocate

biosolids?

Incineration

Landfill

CompostProcess

LandApplication

Ash

LandfillGas

Compost

FertilizerApplication

CarbonTax

Atmosphere

CO2

Decision:How to allocateCO2?

Extend Timber Cycle

New Forest

GeologicalSequestering

Ecosystem

Ecosystem

Underground

Biosolids Eco-Synergy: Problem Formulation

� Multiobjective optimization

� Minimize (Cost, CO2 emissions)

� subject to

� Models of technological systems (incinerator, land fill, land application, composting, geological sequestration)

� Models of ecological systems (forest, timber cycles)

� Carbon tax options

� Determine Pareto curve (win-lose options)

� Choose “best” option by considering all stakeholders

9

10

11

12

Base Case

Process Optimization [Sikdar, 2008]

No Carbon Tax

$15/ton

$30/ton

$50/ton

$75/ton

$100/ton

SL - 41%

SC - 59%

JLA - 100%

Timber - 19%

Forest - 17%

Tax - 64%

SI - 100%

SL - 41%

SC - 59%

JLA - 100%

Timber - 39%

Forest - 26%

Tax - 36%

SI - 50%

SL - 5%

SC - 45%

JLA - 9%

JI - 91%

Current Operation

Total CostMillion $

Biosolids Eco-Synergy: Solution

6

7

8

9

0 5000 10000 15000 20000 25000 30000 35000 40000 45000

Net GHG Released (tons CO2 equiv)

SI - 100%

JLA - 100%

Timber - 14%

Forest - 13%

Tax - 73%

SI - 100%

JLA - 100%

Timber - 29%

Forest - 26%

Tax - 46%

SI - 100%

JLA - 100%

Timber - 29%

Forest - 19%

Tax - 52%

SI - 100%

JLA - 100%

SI - 41%

SC - 59%

JLA - 100%

SL - 41%

SC - 59%

JLA - 100%

Pareto Curve – no tax, no ES

SI - 100%

JLA - 100%

Timber - 41%

Forest - 34%

Geol. - 25%

Zero net CO2

Pareto Curve – with tax, no ES

� Eco-synergy expands design space to allow,

� Identification of new design alternatives

� Closed-loop design within ecological constraints

Conclusions

� Traditional engineering focus on technology and efficiency will not lead to sustainability

� Also true for conventional life cycle approaches

� Need to consider ecosystems

� Compare demand and supply of ecosystem services� Compare demand and supply of ecosystem services

� Include ecosystems in solving design problems

� Techno-Ecological Synergy

� Expands design space by including role of ecosystems

� Enables engineering within ecological constraints

Acknowledgments

� Collaborators� Prof. Gretchen Daily

(Stanford)� Conservation Biology

� Dr. Joseph Fiksel� Corporate sustainability

Prof. Prem Goel

� Graduate Students

� Geof Grubb

� Vikas Khanna

� Shweta Singh

� Bob Urban

Yi Zhang� Prof. Prem Goel� Statistics

� Prof. Bill Mitsch� Ecological engineering

� Post-docs� Dr. Anil Baral

� Dr. Guy Ziv (Stanford)

� Yi Zhang

� Sponsors

� National Science Foundation

� Environmental Protection Agency

� USDA

“Does the educated citizen know he is only a cog in

an ecological mechanism? That if he will work with

that mechanism, his mental wealth and his material

wealth can expand indefinitely? But if he refuses to

work with it, it will ultimately grind him to dust. If

education does not teach us these things, then what is

education for?”

-- Aldo Leopold

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