Anastas/Zimmerman Supporting Information for ES&T A-page feature
“Design Through the 12 Principles of Green Engineering” (March 1, 2003)
Principle 1: Designers need to strive to ensure that all material and energy
inputs and outputs are as inherently nonhazardous as possible.
Principle 2: Preventing waste is better than treating or cleaning it up after it is
formed.
At every design scale, an opportunity exists to prevent waste rather than treat it after it is
generated. Waste requires the expenditure of capital, energy, and resources with no
realized benefit. Examples are presented in Table 1 for molecules, processes, products,
and systems to demonstrate moving from the status quo toward sustainable design
through the application of Principle 2.
TABLE 1
Examples of status quo and application of Principle 2 across design scales
Design scale
Current practice
Application of principle
Protecting groups;
substitution reactions
Dry cleaning with
perchloroethylene
Atom economy (1)
Product
Virgin paper
Paper with recycled content
System
Fossil energy
Fusion energy
Molecular
Process
1
Dry cleaning with
supercritical CO2
Principle 3: Separation and purification operations should be a component of
the design framework.
Separation and purification operations can be designed at every scale to minimize energy
consumption and materials. This design strategy can be used at the beginning of the
product’s life to isolate the desired output or at end of life to aid in the recovery, reuse,
and recovery of materials as illustrated by the examples in Table 2.
TABLE 2
Examples of status quo and application of Principle 3 across design scales
Design scale
Molecular
Process
Product
System
Current practice
Application of principle
Column chromatography;
distillation
Permanent joining/bonding of
two materials
Circuit board masks and etching
using large volumes of organic
solvent
Separation intensive recycling
of municipal waste
Reaction product insoluble in
reaction medium (2)
Reversible fastening
Computer chip manufactured by
vapor deposition
Local/residential material and
energy systems
Principle 4: System components should be designed to maximize mass, energy,
and temporal efficiency.
Processes and systems often use more time, space, energy, and material than are
necessary. Table 3 illustrates examples where designing for maximized efficiency and
intensity moves toward eliminating the design flaw of waste.
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TABLE 3
Examples of status quo and application of Principle 4 across design scales
Design scale
Current practice
Application of principle
Molecular
Batch reactors using large
volumes of solvent
Continuous flow microreactors
(3); spinning disk reactors
Process
Painting
Powder coating
Product
Printed media
Digital media
System
Urban sprawl
Ecoindustrial park planning
Principle 5: System components should be “output-pulled” rather than “inputpushed” through the use of energy and materials.
Extensive energy and material inputs often drive a transformation toward the desired
outcome. This logic has resulted in waste, inefficiency, and environmental damage. Table
4 presents examples at each scale in which the final outcome is “pulled” rather than
“pushed”. This concept can be applied to all design scales minimizing the demand for
resources to obtain the desired output and resulting in a more sustainable design.
TABLE 4
Examples of status quo and application of Principle 5 across design scales
Design scale
Current practice
Application of principle
Molecular
Excess reagent
Dehydration reactions
Process
Coating technologies with high
curing temperature
Fermentation product removal
Product
Metal casting
Direct metal deposition (4)
System
Marketing overproduced items
at a minimal profit
“Just in time” manufacturing
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Principle 6: Embedded entropy and complexity must be viewed as an
investment when making design choices on recycle, reuse, or beneficial
disposition.
The degree of complexity is a function of the expenditure of materials, energy, time, and
capital. These investments should be considered when making design choices on recycle,
reuse, or beneficial disposition. High complexity should generally correspond to reuse,
while lower complexity should correlate with recycling where possible and beneficial
disposition where necessary. Table 5 provides examples of applying Principle 6 at each
design scale and has led to more sustainable design decisions.
TABLE 5
Examples of status quo and application of Principle 6 across design scales
Design scale
Complexity
Current practice
Low
“Flaring” methane at petroleum
refineries
Molecular
High
Low
Process
Complex biomaterials reduced
to hydrocarbon feedstocks
Incorporating used rubber
as a fill material for its
bulk properties
High
Incineration of PET bottles
Low
Landfilling of yard “waste”
Product
High
Low
System
High
Single-use
(nonrechargeable) batteries
Municipal wastewater treatment
sludge to landfill
Under-used public school
buildings torn down
Application of
principle
C-1 (carbon) as a
feedstock for value
added material
Chiral molecules with
multiple stereo centers
Depolymerization of
homopolymers
Regeneration of
Petretec polymer (5)
Using yard “waste” for
mulch
Refurbished/
re-manufactured copiers
Sludge for energy
and/or agricultural
Former schools
converted to senior
centers
Principle 7: Targeted durability, not immortality, should be a design goal.
Persistence of synthetic materials in the environment and biosphere is increasingly
recognized as incompatible with sustainability, and some of these examples are listed in
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Table 6. The targeted durability of product, process, and system levels can help avoid the
legacy of environmental impacts that have historically caused extensive concerns.
TABLE 6
Examples of status quo and application of Principle 7 across design scales
Design scale
Current practice
Application of principle
Molecular
Polyacrylic acid
Polylactic acid (6)
Process
Paper coating with petroleumbased polymers
Product
Polystyrene packaging material
System
Utility energy sales
Paper coating with renewable,
biodegradable polymers
Eco-fill (7)
(starch-based packing peanut)
Energy efficiency
buy-back programs
Principle 8: Design for unnecessary capacity or capability should be considered
a design flaw. This includes engineering “one-size-fits-all” solutions.
Table 7 provides examples of where historical “overengineering” in unsustainable ways
has caused environmental concerns and where the application of Principle 8 has and can
result in more sustainable products, processes, and systems.
TABLE 7
Examples of status quo and application of Principle 8 across design scales
Design scale
Current practice
Application of principle
Molecular
Excessively reactive reagents
Enzyme catalysts under mild
conditions
Process
Overchlorinating or
overdisinfecting domestic
drinking water
Real-time process analysis/
controlled systems (8)
Product
“Off-the -shelf” technologies
System
Shipping by underutilized fixed
capacity vehicles
5
Technologies specific to needs
and demands of end user
Shipping by rail with railcars
that can attach or detach as
needed
Principle 9: Multicomponent products must minimize material diversity and strive
for using materials that promote disassembly and value retention.
In certain design fields and engineering specialties, up-front design will determine to
what degree a product can be disassembled and the value recovered. The application of
Principle 9 to the examples in Table 8 illustrate how movement from the status quo to
next-generation design can be accomplished across scales.
TABLE 8
Examples of status quo and application of Principle 9 across design scales
Design scale
Current practice
Molecular
Multistep syntheses
Process
Plastics with dyes,
Plasticizers and elasticizers
Product
Vehicle door panel based on
multiple plastic types
System
Analog photography developing
Application of principle
One-pot reactions, cascading
reactions, self-assembly (9)
Properties of polymers built into
the backbone (10)
Vehicle door panel based on
monomaterial (i.e.,
polypropylene) synthesized to
meet mechanical property
demands
Digital photography developing
Principle 10: Design of processes and systems must include integration of
interconnectivity with available energy and materials flows.
While the list of examples in Table 9 shows the importance of interconnectivity of
material and energy flows in moving toward sustainability from the current status quo,
there are important caveats. Design for interconnectivity requires that the designer
recognize that such integrated systems can be either very stable or very vulnerable to
isolated failure causing cascading impacts. The positive impacts of integrating flows on
sustainability are an essential design element.
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TABLE 9
Examples of status quo and application of Principle 10 across design
scales
Design scale
Current practice
Application of principle
Molecular
Neutralizing waste acids to
waste salts
Using “waste” nitrous oxide as
in-process oxidant (11)
Process
Flaring at refineries
Cogeneration of energy
Product
Braking systems integrated with
drive trains based on internal
combustion engines
Regenerative braking in hybrid
electric cars (12)
System
Municipal solid waste/landfill
Kalundborg, Denmark
Principle 11: Performance metrics include designing for performance in
commercial “afterlife”.
Table 10 features examples of how Principle 11 can be used to design products,
processes, and systems for commercial afterlife, ensuring that the impacts are nonharmful
if not beneficial. With forethought, design can ensure performance and value long after
initial commercialization.
TABLE 10
Examples of status quo and application of Principle 11 across design
scales
Design scale
Current practice
Application of principle
Molecular
Polyester fabrics
Nylon 66
Process
Single-purpose unit process
Flexible manufacturing
Product
Personal electronics (cellular
phones, PDAs, laptop
computers)
Xerox copiers (13)
System
Single-purpose/use buildings
Convert industrial buildings
to housing at end of business
life
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Principle 12: Material and energy inputs should be renewable and from readily
available sources throughout all life-cycle stages.
Table 11 illustrates how applying Principle 12 to current practices can help move toward
sustainability and ensuring material and energy inputs are renewable rather than
depleting, where technically and economically feasible. While moving toward renewable
material and energy sources will require extensive innovation and infrastructure,
examples already exist where these types of technologies have been successfully
commercialized.
TABLE 11
Examples of status quo and application of Principle 12 across design
scales
Design scale
Current practice
Application of principle
Molecular
Petroleum-based feedstocks
Recovered biomass feedstock
Process
Wastewater/water treatment by
chemically based systems
Wastewater/water treatment by
natural ecosystems (14)
Product
Petroleum-based plastics
Bio-based plastics
System
Hazardous waste site soil
extraction/cleaning
Phytoremediation
References
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(4) Mazumder, J.; Schifferer, A.; Choi, J. Mater. Res. Innov.
1999, 3, 118–131.
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(5) U.S. EPA Presidential Green Chemistry Challenge;
www.epa.gov/greenchemistry/docs/award_recipients_1996_2002.pdf
(6) Green, C. AURI Agric. Innov. News 1999, 8, 4.
(7) Drumright, R. E.; Gruber, P. R.; Henton, D. E. Adv. Mater. 2000, 12, 1841–1846.
(8) Illman, D. L.; Callis, J. B.; Kowalski, B. R. Am. Lab. 1986, 12, 8–10.
(9) Whitesides, G. M. MRS Bull. 2002, 27, 56–65.
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(12) Lovins, A. Hypercars: The Next Industrial Revolution. In Proceedings from
IEEE Aerospace Applications Conference, Snowmass, CO, 1996.
(13) Smith, H. Ind. Environ. 1997, 20, 54–56.
(14) Riggle, D; Gray, K. BioCycle 1999, 40, 40–41.
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