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American Institute of Chemical

Engineers – Delaware Valley Section

An Introduction to Green Chemistry and Engineering

November 18th 2011

Ken Rollins CEng, FIChemE

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American Institute of Chemical Engineers –

Delaware Valley Section

What is green chemistry and what is green

engineering?

Green chemistry/green engineering is

concerned with the design and use of

processes and products that are feasible and

economical while minimizing the risk to human

health and the environment, and the

generation of pollution at source.

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American Institute of Chemical Engineers –

Delaware Valley Section

The Twelve Principles of Green Chemistry 1. Prevent Waste

2. Safer Chemicals and Products

3. Less Hazardous Chemical Syntheses

4. Use Renewable Feedstocks

5. Use Catalytic Reactions

6. Avoid Chemical Derivatives

7. Maximise Atom Economy

8. Safer Solvents and Reaction Conditions

9. Increased Energy Efficiency

10. Design Chemicals to Degrade after Use

11. Pollution using Real Time Analysis

12. Minimize Accident Potential

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American Institute of Chemical Engineers –

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Principle #1 - Prevent Waste

Design chemical syntheses to prevent waste. Leave no waste

to treat or to clean up

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American Institute of Chemical Engineers –

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Principle #2 – Safer Chemicals & Products

Design chemicals/products to be fully effective but with little

or no toxicity

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American Institute of Chemical Engineers –

Delaware Valley Section

Principle #3 - Less Hazardous Chemical

Syntheses

Design reactions to use and/or generate chemicals with

little or no toxicity to humans, and with low environmental

impact

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American Institute of Chemical Engineers –

Delaware Valley Section

Principle #4 - Use Renewable Feedstocks

Use raw materials that are renewable rather than depleting.

Bio-based materials or other processes’ waste materials,

rather than fossil-based materials – oil, coal

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Principle #5 - Use Catalytic Reactions

Catalysts are renewable and can be re-used many times, in

preference to the use of excess stoichiometric reagents

which generate wstes

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American Institute of Chemical Engineers –

Delaware Valley Section

Principle # 6 - Avoid Chemical Derivatives

Avoid chemical derivatives used as ‘temporary by-products’,

which generate wastes

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Principle # 7 – Maximize Atom Economy

The final product should contain the maximum number of

atoms in the the starting materials

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Principle # 8 – Use Safer Solvents and

Reaction Conditions

Avoid solvents if possible. Consider using water or other

innocuous materials. Minimize

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Alternate ‘Green’ Solvents

• Supercritical Carbon Dioxide

• Supercritical Water

• Ionic Liquids

.

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Biomimicry

Imitate Mother Nature ?

How about a material with the strength of a Spider’s web ?

One of Paul Anastas’ examples. A glue that mimicked the

adhesive power of a limpet ?

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American Institute of Chemical Engineers –

Delaware Valley Section

Principle # 9 – Increased Energy Efficiency

Operate at ambient temperature and atmospheric pressure

where possible

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Delaware Valley Section

Principle # 10- Design Chemicals to

Degrade after Use

Choose materials that will degrade after use rather than

those that will accumulate in the environment

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Delaware Valley Section

Principle # 11- Analyze in Real Time

Use real time process analysis to monitor and control

reactions rather than historical data

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Principle # 12 - Minimize Accident

Potential

Minimize the potential for fires, explosions and other

hazards by selection of chemicals and their forms

(gas/liquid ?)

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American Institute of Chemical Engineers –

Delaware Valley Section

ACS – GCI Pharma Roundtable

Much of the work in promoting green chemistry and

engineering is undertaken by the Green Chemistry Institute –

an arm of the American Chemistry Society.

Together with most of the major pharmaceutical

manufacturers, they have established the ACS GCI Pharma

Roundtable to catalyze the implementation of green

chemistry and green engineering within that industry

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American Institute of Chemical Engineers –

Delaware Valley Section

Concept of Process Mass Intensity

One of the concepts to come out of the ACS GCI Pharma

Roundtable is that of Process Mass Intensity. This is defined as the summation of the mass of all materials used in a process, including water, catalysts, solvents and reagents, divided by the mass of product. The PMI index is used as an indication of ‘greenness’

In the petroleum industry this PMI has a value a little over unity, and increases through general chemicals and specialty chemicals industries. The pharmaceutical industry demonstrates the highest PMIs – often over 100

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American Institute of Chemical Engineers –

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ACS-GCI Solvent Selection Guide

The Roundtable has also published, in April 2011, a Solvent

Selection Guide. Industrial organic solvents are assessed in

terms of safety, health, environmental impact on air, water,

and waste. These assessments are ranked on a scale of 1-

10, with 1 being the most desirable and 10 the least. This

guide is color coded with scores of 1-3 in green, 4-7 yellow

and 8-10 in red.

American Institute of Chemical Engineers

– Delaware Valley Section

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American Institute of Chemical Engineers –

Delaware Valley Section

GCN & NNFCC in the UK

Two leading promoters of Green Chemistry and Engineering

in the UK

• Green Chemistry Network – based out of the University

of York

• National Non-Food Crops Centre (NNFCC)

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American Institute of Chemical Engineers –

Delaware Valley Section

The Twelve Principles of Green Engineering 1. Ensure Inherent Safety

2. Prevent Waste rather than Treat Waste

3. Separation & Purification to Minimize Energy and Materials Use

4. Maximize Mass, Space, Energy and Time Efficiency

5. Output Pulled rather than Input Pushed

6. Conserve Complexity

7. Durability rather than Immortality

8. Meet the Need while Minimizing Excess

9. Minimize Material Diversity

10. Integrate Material and Energy Flows

11.Design for a Commercial Afterlife

12.Renewable rather than Depleting

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Delaware Valley Section

Principle #1 - Ensure Inherent Safety

Strive to ensure that all materials and energy

inputs/outputs are as inherently non-hazardous as possible

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Inherent Safety as Applied to a Chemical

Process

A chemical process is inherently safer if it reduces or

eliminates the hazards associated with materials used and

operations, and that this reduction or elimination is a

permanent and inseparable part of that process

Per Trevor Kletz and Dennis Hendershot

American Institute of Chemical Engineers –

Delaware Valley Section

Concepts of Inherent Safety Intensification Using less of a hazardous material.

Smaller (intensified) equipment can reduce the

hazardous inventory and minimize the consequences

of accidents

Attenuation Using a hazardous material in a less

hazardous form, for example, a diluted acid rather

than a concentrated one. Larger particle size to

minimize a dust explosion hazard.

Substitution Using safer material. Water instead of a

flammable solvent.

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American Institute of Chemical Engineers –

Delaware Valley Section

Principle #2 - Prevent Waste rather than

Treat Waste

Better to prevent waste streams occurring rather than

treating them afterwards

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Principle #3 - Separation & Purification

Operations Selection

Separation & Purification Operations Designed to Minimize

Energy and Materials Use

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American Institute of Chemical Engineers –

Delaware Valley Section

Principle #4 - Maximize Efficiencies

Processes and products should be designed to maximize

Mass, Space, Energy and Time Efficiencies

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American Institute of Chemical Engineers –

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Principle #5 - Output Pulled not Input Pushed

Often a reaction or transformation is "driven" to completion by

adding more energy/materials to shift the equilibrium to

generate the desired output. However, this same effect can be

achieved by designing reactions in which outputs are removed

from the system, and the reaction is instead "pulled" to

completion without the need for excess energy/materials.

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American Institute of Chemical Engineers –

Delaware Valley Section

Principle #6 - Conserve Complexity

Value-conserving recycling, where possible, or beneficial

disposition, when necessary, End-of-life design decisions

for recycle, reuse, or beneficial disposal should be based

on the invested material and energy and subsequent

complexity

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American Institute of Chemical Engineers –

Delaware Valley Section

Industrial Symbiosis at Kalundborg, Denmark

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Delaware Valley Section

Principle #7 - Durability rather than

Immortality

Targeted durability should be a design goal

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American Institute of Chemical Engineers –

Delaware Valley Section

CFCs These coolant chlorofluorocarbons are:

Non-flammable

Non-toxic

Effective

Inexpensive

Stable – so stable that they migrate to the upper atmosphere,

where UV-induced fragmentation causes ozone depletion

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American Institute of Chemical Engineers –

Delaware Valley Section

Principle #8 - Meet the Need, Minimizing Excess

Designing for unnecessary overcapacity or over capability is a

design flaw

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Principle #9 - Minimize Material Diversity

Material diversity in multi-component systems is to be

minimized

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Delaware Valley Section

Principle #10 - Integrate Material & Energy Flows

• Water Loop Closure

• Integrate Heat/Cool Loops

• Cogeneration

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American Institute of Chemical Engineers –

Delaware Valley Section

Pinch Technology

Pinch technology, developed principally by Bodo Linnhoff at

the University of Manchester in the UK, is a methodology for

the integration of heating and cooling systems for

maximizing energy efficiency.

American Institute of Chemical Engineers –

Delaware Valley Section

Simple Heat Exchange System

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Hot Stream

3500 lb/hr

400 deg

F

70 deg F

Coolant 0.98MM Btu/hr

Cold Stream

4000 lb/hr

90 deg

F

400 deg F

Heating

0.87MM Btu/hr

American Institute of Chemical Engineers –

Delaware Valley Section

Integrated Heating and Cooling

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Hot Stream

3500 lb/hr

400 deg F

70 deg F

Coolant

0.67MM Btu/hr

Cold Stream

4000 lb/hr

200 deg F

90 deg F

Heating

0.56MM Btu/hr

290 deg F

400 deg F

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American Institute of Chemical Engineers –

Delaware Valley Section

Principle #11 - Design for a Commercial

Afterlife

Products and processes should be designed for a commercial

afterlife

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Principle #12 - Renewable not Depleting

Material and energy inputs should be from renewable

resources not depleting resources

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American Institute of Chemical Engineers –

Delaware Valley Section

Green Corrosion Inhibitors

Traditional corrosion protection methods often rely on

hazardous substances, notably carginogenic chromates.

Research in Europe is demonstrating the use of ‘intelligent’

self healing inhibitors. The controllable delivery is based on

incorporating nano-containers of organic inhibitors in

protective films of silica and zirconia – both benign and

abundant. Release of material in triggered by pH.

taken from GCN Newsletter (UK) April 2007

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American Institute of Chemical Engineers –

Delaware Valley Section

Biocatalysis – the use of enzymes or whole

cells in the manufacturing process .

Bicatalysts can simplify or enable production of complex

molecules. These often eliminate the requirement for

elaborate separation and/or purification steps. Reactions may

be undertaken under milder conditions of temperature,

pressure and pH. Such biocatalytic reactions are by nature

safer.

American Institute of Chemical Engineers –

Delaware Valley Section

Microchannel Reactors

The use of microchannel reactors for catalytic hydrogenation

reactions has the potential to improve a significant number of

catalytic hydrogenation reactions in both the chemical and

pharmaceutical industries.

These reactors could significantly improve the efficiency and

safety of such manufacturing processes. These reactors

possess small transverse dimensions with high surface-to-

volume ratios and consequently exhibit enhanced heat and

mass-transfer rates.

Taken from a Promotional Brochure from US Dept. of Energy

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American Institute of Chemical Engineers –

Delaware Valley Section

Metabolic Pathway Engineering

Genetic modification of micro-organisms to make them

produce the desired chemical.

Many examples – ethanol, 1.3 PDO, 1,4 BDO, succinic acid etc

etc.

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American Institute of Chemical Engineers –

Delaware Valley Section

Acknowledgements

Jacobs & KBR for supporting this webinar – hopefully they will continue throughout the series

My peer reviewers – Linda, Jasmine and Bob

Paul Anastas & David Shonnard – for their published works which have contributed so much to this material

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American Institute of Chemical Engineers –

Delaware Valley Section

Questions ?