Green ChemistryHASSAN A. H. Al-BARKing Abdulaziz University, Chem. Dept.,

Jeddah, Saudi Arabia E-Mail: halbar@kau.edu.sa

Homepage: kau.edu.sa/halbar

11 Apr. 2008

Sustainable Chemistry Developments

Indroduction: The Pollution Prevention Act of 1990 established a national policy to prevent orreduce pollution at its source whenever feasible. The Pollution Prevention Act also provided anopportunity to expand beyond traditional EPA programs and devise creative strategies to protecthuman health and the environment. Green chemistry is the use of chemistry for pollutionprevention. More specifically, green chemistry is the design of chemical products andprocesses that reduce or eliminate the use and generation of hazardous substances.

What is Green Chemistry?

The principles of green chemistry focus on reducing, recycling, or eliminating the use of toxicchemicals i chemistry by finding creative ways to minimize the human and environmentalimpact without stifling scientific progress.

Green chemistry is a highly effective approach to pollution prevention because it applies innovativescientific solutions to real-world environmental situations. What is Green Chemistry?

In a recent book on the subject, green chemistry was defined as

"The utilization of a set of principles that reduces or eliminates the use or generationof hazardous substances in the design, manufacture, and application of chemicalproducts."

Chemical synthesis which takes into account environmental considerations in the selectionof reactants and reaction conditions is growing in importance as both industrial andacademic researchers become aware of the environmental and economic advantages of anenvironmentally benign or "green" approach. The principles of a green approach are notcovered in traditional chemistry courses, perhaps contributing to its slow growth as an area ofacademic research.

Twelve Principles of Green Chemistry1. Prevent waste: Design chemical syntheses to prevent waste, leaving no waste to treat or clean up. 2. Design safer chemicals and products: Design chemical products to be fully effective, yet have little or

no toxicity. 3. Design less hazardous chemical syntheses : Design syntheses to use and generate substances with little

or no toxicity to humans and the environment. 4. Use renewable feedstocks: Use raw materials and feedstocks that are renewable rather than depleting.

Renewable feedstocks are often made from agricultural products or are the wastes of other processes;depleting feedstocks are made from fossil fuels (petroleum, natural gas, or coal) or are mined.

5. Use catalysts, not stoichiometric reagents: Minimize waste by using catalytic reactions. Catalysts areused in small amounts and can carry out a single reaction many times. They are preferable tostoichiometric reagents, which are used in excess and work only once.

6. Avoid chemical derivatives: Avoid using blocking or protecting groups or any temporary modificationsif possible. Derivatives use additional reagents and generate waste.

7. Maximize atom economy: Design syntheses so that the final product contains the maximum proportionof the starting materials. There should be few, if any, wasted atoms.

8. Use safer solvents and reaction conditions: Avoid using solvents, separation agents, or other auxiliarychemicals. If these chemicals are necessary, use innocuous chemicals.

9. Increase energy efficiency: Run chemical reactions at ambient temperature and pressure wheneverpossible.

10.Design chemicals and products to degrade after use: Design chemical products to break down toinnocuous substances after use so that they do not accumulate in the environment.

11.Analyze in real time to prevent pollution: Include in-process real-time monitoring and control duringsyntheses to minimize or eliminate the formation of byproducts.

12.Minimize the potential for accidents: Design chemicals and their forms (solid, liquid, or gas) tominimize the potential for chemical accidents including explosions, fires, and releases to theenvironment.

Sustainable Chemistry Developments

Chemical products and processes should be designed to the highest level of thishierarchy and be cost-competitive in the market.

1.Green Chemistry: Source Reduction/Prevention of Chemical Hazards Design chemical products to be less hazardous to human health and the

environment* Use feedstocks and reagents that are less hazardous to human health and the

environment* Design syntheses and other processes to be less energy and materials

intensive (high atom economy, low E-factor) Use feedstocks derived from annually renewable resources or from abundant

waste Design chemical products for increased, more facile reuse or recycling

2.Reuse or Recycle Chemicals 3.Treat Chemicals to Render Them Less Hazardous 4.Dispose of Chemicals Properly

Chemicals that are less hazardous to human health and the environment are:

Less toxic to organisms and ecosystems Not persistent or bio-accumulative in organisms or the environment Inherently safer with respect to handling and use

Finding creative ways to reduce hazard and waste has been the goal of manyacademic labs across the country.

In recent history, the trend has been toward "microscale" methods ; usingsmaller quantities of reactants to minimize the impact.

In contrast, green chemistry focuses on using less toxic reactants in the firstplace, thus reducing the need to use microscale methods. Students in agreen chemistry lab can use quantities more typical of an industrialsetting than their counterparts in a microscale lab. Finding realisticsolutions to environmental concerns in academic labs should prove to be aboon to industry as they look for employees ready to meet the demands of thefuture of science.

History OF Green Chemsitry:Shortly after the passage of the Pollution Prevention Act of 1990, the Office ofPollution Prevention and Toxics (OPPT) explored the idea of developing new orimproving existing chemical products and processes to make them less hazardous tohuman health and the environment. In 1991, OPPT launched a model researchgrants program called "Alternative Synthetic Pathways for Pollution Prevention". Thisprogram provided unprecedented grants for research projects that include pollutionprevention in the design and synthesis of chemicals. In 1993, the program wasexpanded to include other topics, such as greener solvents and safer chemicals, andwas renamed "Green Chemistry." Since then, the Green Chemistry Program has builtmany collaborations with academia, industry, other government agencies, and non-government organizations to promote the use of chemistry for pollution preventionthrough completely voluntary, non-regulatory partnerships.

Presidential Green Chemistry ChallengeIn 1995, OPPT launched the Presidential Green Chemistry Challenge , a voluntary partnership tosupport further green chemistry research and recognize outstanding examples of green chemistry.The Presidential Green Chemistry Challenge Awards highlight successes in research,development, and industrial implementation of technologies that prevent pollution at the sourcewhile contributing to the competitiveness of the innovators. Nominations for awards are judged forhow well they meet the selection criteria: novelty, environmental and human health benefits, andimpact or applicability in industry.

The Awards provide a rich source of examples of how proactive design of chemical products andprocesses benefit the triple bottom line and move our society towards sustainability.

Top of page

GoalsEPA's Green Chemistry Program promotes the research, development, and implementation ofinnovative chemical technologies that accomplish pollution prevention in a scientifically sound andcost-effective manner. To accomplish these goals, the Green Chemistry Program recognizes andsupports chemical technologies that reduce or eliminate the use or generation of hazardoussubstances during the design, manufacture, and use of chemical products and processes. Morespecifically, the Green Chemistry Program supports fundamental research in the area ofenvironmentally benign chemistry as well as a variety of educational activities, internationalactivities, conferences and meetings, and tool development, all through voluntary partnershipswith academia, industry, other government agencies, and non-government organizations.

Teaching Green Chemistry in the Lab - the Story of CH337G

In 1998-99 a green lab was offered as an alternative to the normal organic lab sequence at the University of Oregon. This twoterm sequence, taught by Jim Hutchison and Ken Doxsee consisted of two sections with twelve students each. Additionally, threeteaching assistants, Marvin Warner, Scott Reed, and Brad Wan worked with the students in the lab and continue to optimize andtest new green laboratory experiments. For the 1999-00 year, the green lab will be expanded to a class of 30 students, to furthertest the experiments, conduct monitoring of waste production and air monitoring.

One of the challenges in developing this course was developing newlaboratory experiments, as there are very few examples in current labmanuals. Our criteria for identifying green experiments for this curriculumwere that each experiment:

Illustrates green chemical concepts (e.g. recycling, hazardreduction, solvent reduction)

Teaches modern reaction chemistry and techniques

Complements the lecture course and provides a platform fordiscussion of environmental issues in the classroom

Can be accomplished by students given the time (3 hours) andmaterial constraints of a typical student organic laboratory

Is adaptable to either macroscale or microscale methods

Uses inexpensive, greener solvents and reagents

Reduces laboratory waste and hazards

The Microscience Approach

The initial development of the microscience approach focusedon secondary school needs, particularly in chemistry. Providingpractical experiences in chemistry is a priority becausechemicals are consumables, giving rise to high running costsand significant hazard and environmental impact, if used on thetraditional scale. Furthermore there is a need to contribute tolife skills development for all future citizens, as regards"chemical literacy". The microscience approach has met thischallenge very successfully and stimulated interest in itsapplication at other educational levels and in other sciences.

What is Microscale Chemistry?

How to maintain a pollution-free environment and how to handle chemical wastesare subjects of increasing concern to all scientists, educators and the generalpublic.

The best way to succeed in this effort is by eliminating chemical waste at thesource. Reduction of chemical use to the minimum level at which experiments canbe effectively performed is known as Microscale Chemistry.

Microscale chemistry is an environmentally safe pollution prevention method ofperforming chemical processes using small quantities of chemicals with outcompromising the quality and standard of chemical applications in education andindustry.

Microscale Chemistry is performed by using:

Drastically reduced amounts of chemicals Safe and easy manipulative techniques Miniature labware and high quality skills

Microscale Chemistry amounts to a Total Quality Management (TQM) approach tothe use of chemicals. Microscale Chemistry is recognized as Smallscale Chemistryby the International Union of Pure and Applied Chemistry

Teacher & Student

Time

The safety and securityEnvironmental

Economical

Training

Applications

Practical Application

Understands & memorizes

memorizesUnderstands

S.D 1

Discipline

Punctuality

Honesty

Good manners

Hard work

Good conduct

Patience

Responsiveness

The teaching methods for the strategies

continuity between the teacher and student

Scientism and

theoretical system

Scientific experiments ,

practical systemArtistry proficiency

Handmade proficiency

Ideological proficiency Scientism

proficiencyStudent

Conscience collectionThinking collection

Proficiency collection Handmade collection

Researcher

S.D.1

Cost Time

Quality

.

.Continuous Improvement

Systemic entrance in

teaching and learning sciences courses

Green Sciences in

Scientific and research Training Search Training and high

studies under the supervison of Scientific

Research

Quality Triangle is designed by the help of Dr.Hamed

Elwan

Showing the quality in more

than ten workshops and Conferences

Experiment Viewing Deduction

Application from Life

Scientific Application

Theoretical Methodology

applicationاfrom Faith

H2S(g)

NO2(g)

SO2(g)

- Na3F

- H2O

- NaCl

- H2O

- NaCl

- H2O

CO2(g)

+

HCl

+

+

+

+ +

NaNO2

- NaCl- H2O

Na2CO3

NaHCO3

- NaCl

- H2O

- NaCl

- H2O

Na2S2O3

Na2SO3

FeS

Reference: scientific book coves the course of general basis of chemistry:System of Green Chemistry Experiments in General Chemistry Basis

Finding mole size from a gas under the standard conditions

2KClO4

2 KCl + 3 O2

MnO2

Water size=resulted Oxygen=7.223 mg

Designed byHassan Al Bare and Ali Masaud

2HCl + Mg MgCl2 + H2

0.5 ml 1.13 mg 12 ml

Determination of Gas constant

تصميموعلى البار حسن

مسعود

2HCl + Mg MgCl2 + H

2

0.5 ml 1.13 mg 12 ml

تصميممسعود وعلى البار حسن

Determination of O2 in the Air

0.3 mL of Phenol Derv. & 1.2 gm NaOH

Vol. of the air absorbed in the close system = 2.6 mL

20

على التدريب استراتيجية عن توضيحية تجاربإجراء

علوم نظام باستعمال العملية التجاربالميكروسكال

GR

EEN

CH

EM

ISTR

Y2005

التجربة في المستخدم للجهاز صورة

21

Determination of the Percent Composition and simplest formula

OR Zn + HCl H2 Metal Oxide ………..

Glass Fusion

MnO2

O2

CyclohexaneOr ethylacetateOr benzoic acid

.

Comboplate

H2O absorber A

Mg(ClO4)

2

CO2 absorber B

Finely divided NaOH supported on asbestos.

Furnace

Silicone tube

Microstand

Syring H

2O

2

Lid 1

A B

Inside the Comboplate wt. of H2O and CO

2 will get

them from the different the two beakers A & B (contain the absorbers) before and after the experiment.

Comboplate

Continuous Improvement team that follows up Teacher, Student, Supervisor and

Technician’s Performance

Program of Micro Chem Green Sciences

SupervisorTeacherTechnicians

Learner

Trainee

Continuous Improvement Team that followed to

Comprehensive Quality

Administration

Technical Team for Training .........

Committee of Training Following

Up

Appraisal questionnaire of each experiment in the green scientific programThe scientism: ………………………. course: ……..……… The name of exp.: ………….……Teacher name: …………………………. The purpose from exp.: ……………….……..………….Observation: ………………..….. Results: ………..…………. Comments: …………….............

Put yes or no and/or other suitable symbol on the ration of percentage in the using of the green scientific technique:

No. Statement -- -- -- -- --

1The rate of suitability exp. at your systemorder school

1 2 3 4 5

2 The easy in the run of exp. easy - medium - Difficult

3The time of demonstrated exp. Withcomparable traditional method

lessin

timeequal

Longthan

4The rate of safety and security through theexp. Running

1 2 3 4 5

5 The rate of pollution obtained from exp. 1 2 3 4 56 The rate of approach realization from the exp. 1 2 3 4 5

7The rate of the significance technique for pupilstudent

1 2 3 4 5

8The chemical quantity used in the exp. Withother method techniques

Verylittle

Little Mediumequivalent

9 The ability of the student to accept that exp. 1 2 3 4 510 The rate of newness their technique 1 2 3 4 5

11

The rate of positive action at the time ofrunning with your student civilized action ,with insert.

1 2 3 4 5

12Your insert. of laying lay this technique at yourschool

Strongly

Normal Refused

13

The rate in the use of systematic technique forthe binding between the net results of exp .and the theoretical system

1 2 3 4 5

14The extent of your opinion for lute of exp.Result with conclusion study system

1 2 3 4 5

15

The rate of the student assimilation for thetheoretical part in which its supported theexperiment

1 2 3 4 5