1 2

Alvaro Alvaro OrjuelaOrjuela LondoLondoññoo, PhD., PhD.

Associate professorAssociate professor

Department of Chemical and Environmental EngineeringDepartment of Chemical and Environmental Engineering

Universidad Universidad NacionalNacional de Colombia, Bogotde Colombia, Bogotáá

Green Engineering PrinciplesGreen Engineering Principles

3

12 Principles12 PrinciplesPrinciple 1: Inherent rather than Principle 1: Inherent rather than

circumstantial.circumstantial.

●● Ideally, inputs to the system will be inherently less hazardous,Ideally, inputs to the system will be inherently less hazardous,

which significantly reduces the risks of failure and the which significantly reduces the risks of failure and the

resources expended on control, monitoring, and containment.resources expended on control, monitoring, and containment.

●● Significant investment of time, capital, material, and energy Significant investment of time, capital, material, and energy

resources.resources.

●● Evaluate inherent nature of the selected material and energy Evaluate inherent nature of the selected material and energy

inputsinputs

●● If inherently hazardous inputs are selected, If inherently hazardous inputs are selected, -- removal during removal during

purification or cleanup steps, or incorporated into the final purification or cleanup steps, or incorporated into the final

output (recycle).output (recycle).

●● Eventual removal to a permanent offEventual removal to a permanent off--site storage and site storage and

disposal facility.disposal facility.

●● Incorporating hazards into a product or process as long as Incorporating hazards into a product or process as long as

the hazard is continually recycled and reusedthe hazard is continually recycled and reused

Principle 2: Prevention instead of Principle 2: Prevention instead of

treatmenttreatment

●● Zero waste in unfeasible (thermodynamics)Zero waste in unfeasible (thermodynamics)

●● At every design scale, an opportunity exists to prevent waste At every design scale, an opportunity exists to prevent waste

rather than treat it after it is generated. rather than treat it after it is generated.

●● Find alternative ways to use waste when producedFind alternative ways to use waste when produced

●●Waste requires the expenditure of capital, energy, and Waste requires the expenditure of capital, energy, and

resources with no realized benefit. resources with no realized benefit.

Design scale Current practice Application of principle

Molecular Protecting groups;

substitution reactions Atom economy (1)

Process Dry cleaning with perchloroethylene

Dry cleaning with supercritical CO2

Product Virgin paper Paper with recycled content

System Fossil energy Fusion energy

Principle 3: Design for separationPrinciple 3: Design for separation

●● Separation and purification operations can be designed at Separation and purification operations can be designed at

every scale to minimize energy consumption and materials every scale to minimize energy consumption and materials

●● At the beginning of the productAt the beginning of the product’’s life to isolate the desired s life to isolate the desired

output, or at end of life to aid in the recovery, reuse, and output, or at end of life to aid in the recovery, reuse, and

recovery of materials recovery of materials

Design scale Current practice Application of principle

Molecular Column chromatography;

distillation Reaction product insoluble in

reaction medium (2)

Process Permanent joining/bonding of

two materials Reversible fastening

Product Circuit board masks and etching using large volumes of organic

solvent

Computer chip manufactured by vapor deposition

System Separation intensive recycling

of municipal waste Local/residential material and

energy systems

Principle 4: Maximize mass, energy, space, Principle 4: Maximize mass, energy, space,

and time efficiencyand time efficiency

●● Processes and systems often use more time, space, energy, Processes and systems often use more time, space, energy,

and material than are necessary and material than are necessary

●● Inefficiencies generate wasteInefficiencies generate waste

●●Optimized systems Optimized systems -- need for realneed for real--time monitoring time monitoring -- ensure ensure

operation under intended design conditions.operation under intended design conditions.

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: OutputPrinciple 5: Output--pulled versus inputpulled versus input--

pushedpushed

●● Extensive energy and material inputs often drive a Extensive energy and material inputs often drive a

transformation toward the desired outcome. transformation toward the desired outcome.

●● This logic has resulted in waste, inefficiency, and This logic has resulted in waste, inefficiency, and

environmental damageenvironmental damage

●●Manufacturing systems can be based on Manufacturing systems can be based on ““justjust--inin--timetime””

manufacturing manufacturing

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

Principle 6: Conserve complexityPrinciple 6: Conserve complexity

●● The degree of complexity is a function of the expenditure of The degree of complexity is a function of the expenditure of

materials, energy, time, and capital. materials, energy, time, and capital.

●● These investments should be considered when making These investments should be considered when making

design choices on recycle, reuse, or beneficial disposition.design choices on recycle, reuse, or beneficial disposition.

●●High complexity should generally correspond to reuse, while High complexity should generally correspond to reuse, while

lower complexity should correlate with recycling where lower complexity should correlate with recycling where

possible and beneficial disposition where necessary. possible and beneficial disposition where necessary.

Principle 6: Conserve complexityPrinciple 6: Conserve complexity

●● Examples Examples

Design scale Complexity Current practice Application of

principle

Low “Flaring” methane at petroleum

refineries

C-1 (carbon) as a feedstock for value

added material Molecular

High Complex biomaterials reduced

to hydrocarbon feedstocks Chiral molecules with

multiple stereo centers

Low Incorporating used rubber

as a fill material for its bulk properties

Depolymerization of homopolymers

Process

High Incineration of PET bottles Regeneration of

Petretec polymer (5)

Low Landfilling of yard “waste” Using yard “waste” for

mulch Product

High Single-use

(nonrechargeable) batteries Refurbished/

re-manufactured copiers

Low Municipal wastewater treatment

sludge to landfill Sludge for energy and/or agricultural

System

High Under-used public school

buildings torn down

Former schools converted to senior

centers

Principle 7: Durability rather than Principle 7: Durability rather than

immortalityimmortality

●● Persistence of synthetic materials in the environment and Persistence of synthetic materials in the environment and

biosphere is increasingly recognized as incompatible with biosphere is increasingly recognized as incompatible with

sustainability sustainability

●● The targeted durability of product, process, and system levels The targeted durability of product, process, and system levels

can help avoid the legacy of environmental impacts that have can help avoid the legacy of environmental impacts that have

historically caused extensive concerns historically caused extensive concerns

●● balanced with the design of products that are durablebalanced with the design of products that are durable

Design scale Current practice Application of principle

Molecular Polyacrylic acid Polylactic acid (6)

Process Paper coating with petroleum-

based polymers Paper coating with renewable,

biodegradable polymers

Product Polystyrene packaging material Eco-fill (7)

(starch-based packing peanut)

System Utility energy sales Energy efficiency

buy-back programs

Principle 8: Meet need, minimize excessPrinciple 8: Meet need, minimize excess

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 Technologies specific to needs

and demands of end user

System Shipping by underutilized fixed

capacity vehicles

Shipping by rail with railcars that can attach or detach as

needed

●● Anticipating the necessary process agility and product Anticipating the necessary process agility and product

flexibilityflexibility

●● There is a tendency to design for worstThere is a tendency to design for worst--case scenarioscase scenarios

●● The tendency to design an eternal and global solution should The tendency to design an eternal and global solution should

be minimizedbe minimized

Principle 9: Minimize material diversityPrinciple 9: Minimize material diversity

●●Diversity becomes an issue when considering endDiversity becomes an issue when considering end--ofof--usefuluseful--

life decisions life decisions

●●UpUp--front design will determine to what degree a product can front design will determine to what degree a product can

be disassembled and the value recovered be disassembled and the value recovered

Design scale Current practice Application of principle

Molecular Multistep syntheses One-pot reactions, cascading reactions, self-assembly (9)

Process Plastics with dyes,

Plasticizers and elasticizers Properties of polymers built into

the backbone (10)

Product Vehicle door panel based on

multiple plastic types

Vehicle door panel based on monomaterial (i.e.,

polypropylene) synthesized to meet mechanical property

demands

System Analog photography developing Digital photography developing

Principle 10: Integrate local material and Principle 10: Integrate local material and

energy flowsenergy flows

●● Extensive Design for interconnectivity requires that the Extensive Design for interconnectivity requires that the

designer recognize that such integrated systems can be designer recognize that such integrated systems can be

either very stable or very vulnerable to cascading impacts.either very stable or very vulnerable to cascading impacts.

●● The positive impacts of integrating flows on sustainability are The positive impacts of integrating flows on sustainability are

an essential design element. an essential design element.

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: Design for commercial Principle 11: Design for commercial

““afterlifeafterlife””

●●With forethought, design can ensure performance and value With forethought, design can ensure performance and value

long after initial commercializationlong after initial commercialization

●●Commercial end of life occurs as a result of technological or Commercial end of life occurs as a result of technological or

stylistic obsolescence, rather than a fundamental stylistic obsolescence, rather than a fundamental

performance or quality failure. performance or quality failure.

●● To reduce waste, components that remain functional and To reduce waste, components that remain functional and

valuable can be recovered for reuse and/or reconfiguration.valuable can be recovered for reuse and/or reconfiguration.

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

Principle 12: Renewable rather than Principle 12: Renewable rather than

depletingdepleting

●●Moving toward renewable material and energy sources will Moving toward renewable material and energy sources will

require extensive innovation and infrastructurerequire extensive innovation and infrastructure

●● Every unit of finite substance used incrementally moves the Every unit of finite substance used incrementally moves the

supply of that substance toward depletion supply of that substance toward depletion

●● Virgin substances require repetitive extractive processes, Virgin substances require repetitive extractive processes,

using depleting resources causes ongoing environmental using depleting resources causes ongoing environmental

damage.damage.

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

17

THANK YOU!THANK YOU!

Questions?Questions?