green chemistry – the chemical industries' way to go green

GREEN CHEMISTRY

The Chemical Industries' Way to Go Green

A Presentation by:

Tariq Hashmat TauheedIInd yearB.Tech. Electronics Engg.

Omar Ahmed SiddiquiIInd yearB.Tech Mechanical Engg.

Zakir Husain College of Engineering & Technology

ALIGARH MUSLIM UNIVERSITY

INTRODUCTIONOne of the most widely accepted definition of green chemistry is the one given by the man who coined the term itself, Paul T. Anastas, in the year 1991.O Anastas along with John C. Warner defined Green Chemistry as follows:

"Green Chemistry is the design of

chemical products and processes

that reduce or eliminate the use

and/or generation of hazardous

substances,"

O Paul Anastas is known as the 'Father of Green Chemistry' for his groundbreaking work on the design and manufacture of non-hazardous and environmentally benign chemicals.

O 'Green Chemistry' now is a globally accepted term to describe the movement towards more environmentally acceptable chemical processes and products.

O Green Chemistry is all about REDUCTIONS. These reductions lead to what is known as "Triple Bottom Line Benefits", a combination of Environmental, Economic and Social improvements. This encourages businesses of all kinds to go the green way [4].

GREEN CHEMISTRY IS ABOUT..

Waste

Materials

Hazard

Environmental Impact

COST

Risk

Energy

“It is better to prevent waste than to treat or clean

up waste after it is formed”

ChemicalProcess

OCosts saved by-reduction of expensive-to-

dispose waste, and energy use,-making processes more efficient

reducing material consumption.

OReduction in hazardous incidents and handling of dangerous substances

= add-on social health benefit

Ecological aspects of the Natural Step Systems

Paul Anastas and James Warner together chalked down twelve principles of Green Chemistry to aid in assessing how green a chemical process or a product is [1].

1. PreventionIt is better to prevent waste than to treat or clean up waste after it has

been created.

PRINCIPLES OF GREEN CHEMISTRY

2. Atom Economy

Synthetic methods should be designed to maximize the incorporation of all materials used in the process into the final product.

3. Less Hazardous Chemical Syntheses

Wherever practicable, synthetic methods should be designed to use and generate substances that possess little or no toxicity to human health and the environment.

4. Designing Safer Chemicals

Chemical products should be designed to effect their desired function while minimizing their toxicity.

5. Safer Solvents and AuxiliariesThe use of auxiliary substances (e.g., solvents, separation agents, etc.)

should be made unnecessary wherever possible and innocuous when used.

6. Design for Energy EfficiencyEnergy requirements of chemical

processes should be recognized for their environmental and economic impacts and

should be minimized. If possible, synthetic methods should be conducted at ambient temperature and pressure.

7. Use of Renewable FeedstocksA raw material or feedstock should be renewable rather than depleting

whenever technically and economically practicable.

8. Reduce DerivativesUnnecessary derivatization (use of

blocking groups, protection/ deprotection, temporary modification of physical/chemical processes) should be minimized or avoided if possible, because such steps require additional reagents and can generate waste.

9. CatalysisCatalytic reagents (as selective as

possible) are superior to stoichiometric reagents.

10. Design for DegradationChemical products should be designed

so that at the end of their function they break down into innocuous degradation products and do not persist in the

environment.

11. Real-time analysis for Pollution Prevention

Analytical methodologies need to be further developed to allow for real-time, in-process monitoring and control prior

to the formation of hazardous substances.

12. Inherently Safer Chemistry for Accident Prevention

Substances and the form of a substance used in a chemical process should be

chosen to minimize the potential for chemical accidents, including releases,

explosions, and fire.

THE DRIVERS OF GREEN CHEMISTRY

Green chemistry

Lesshazardous materials

High fines for waste

Producerresponsibility

Government legislation

Lowercapital investment

Loweroperating costs

Economic benefit

Pollution control

Saferand smaller plants

Improvedpublic image

Societal pressure

TOWARDS THE GOAL OF GREEN CHEMISTRY

There is a certain group of technologies or pool of technologies most widely used or studied in achieving the goal towards Green Chemistry. The major ones are summarized in the figure

Industrialecology

Greenengineering

Greenchemistry

Renewableenergy

Practical approaches

Sustainabledevelopment

Strategic goal

Life-cycleassessment

Catalysis

Wastemanagement

E-factor,atom economy

Process intensification

Operational tools

Monitoring tools

THE BIG PICTURE

The application of Green Chemistry at every stage in the lifecycle of a product is of a particularly high importance.

Going green at each step in lifecycle

APPLICATION OF GREEN CHEMISTRY

THE MAJOR USES OF GREEN CHEMISTRY

O Energy

O Global Change

O Resource Depletion

O Food Supply

OEnergy: Green chemistry is essential in developing alternatives of energy generation as well as continue the path towards energy efficiency.

OGlobal Change: The concerns for climate change, global distillation, etc. can be addressed through the development and implementation of green chemistry technologies.

OResource Depletion: Renewable resources can be made increasingly viable technologically and economically through green chemistry.

OFood Supply: Green chemistry can address many food supply issues by developing target specific pesticides, fertilizers with maximum effectiveness, etc.

EXAMPLES OF GREEN CHEMISTRY

O Antifoulants:

Rohm and Haas Company designed Sea-Nine™ replacing the classical TBTO, which though effective, has widespread environmental problems.

O Pest Control:EDEN Bioscience Corporation designed

“Messenger®”, a non-toxic pest-control product, substituting the contemporary pest control methods.

OOxidation:Iron based activators TAML™ containing no toxic group seek to replace chlorine chemistry based polluting oxidation techniques.

ODegradable Polymers:BASF developed product Savant™ made from nylon-6 can be depolymerized and reused. This came as apart of its “6ix Again®” recycling program, thus making it possible to recycle old nylon upholstery fabric back to virgin grade nylon.

CONCLUSIONSGreen chemistry has come a long way since its birth in 1991, growing from a small grassroots idea into a new approach to scientifically-based environmental protection. All over the world, governments and industries are working with ‘green’ chemists to transform the economy into a sustainable enterprise.

Who knows? Green chemistry

may be the next social

movement that will set aside

all the world’s differences

and allow for the creation of

an environmentally

commendable civilization.