Sustainable Chemistry Developments
Green Chemistry
HASSAN A. H. Al-BAR
King Abdulaziz University, Chem. Dept.,
Jeddah, Saudi Arabia
E-Mail:
[email protected]
Homepage:
kau.edu.sa/halbar
11 Apr. 2008
Indroduction: The Pollution Prevention Act of 1990 established a national policy to prevent or
reduce pollution at its source whenever feasible. The Pollution Prevention Act also provided an
opportunity to expand beyond traditional EPA programs and devise creative strategies to protect
human health and the environment. Green chemistry is the use of chemistry for pollution
prevention. More specifically, green chemistry is the design of chemical products and
processes 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 toxic
chemicals i chemistry by finding creative ways to minimize the human and environmental
impact without stifling scientific progress.
Green chemistry is a highly effective approach to pollution prevention because it applies innovative
scientific 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 generation
of hazardous substances in the design, manufacture, and application of chemical
products."
Chemical synthesis which takes into account environmental considerations in the selection
of reactants and reaction conditions is growing in importance as both industrial and
academic researchers become aware of the environmental and economic advantages of an
environmentally benign or "green" approach. The principles of a green approach are not
covered in traditional chemistry courses, perhaps contributing to its slow growth as an area of
academic research.
Twelve Principles of Green Chemistry
Prevent waste: Design chemical syntheses to prevent waste, leaving no waste to treat or clean up.
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 are
used in small amounts and can carry out a single reaction many times. They are preferable to
stoichiometric reagents, which are used in excess and work only once.
6. Avoid chemical derivatives: Avoid using blocking or protecting groups or any temporary modifications
if possible. Derivatives use additional reagents and generate waste.
7. Maximize atom economy: Design syntheses so that the final product contains the maximum proportion
of 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 auxiliary
chemicals. If these chemicals are necessary, use innocuous chemicals.
9. Increase energy efficiency: Run chemical reactions at ambient temperature and pressure whenever
possible.
10.Design chemicals and products to degrade after use: Design chemical products to break down to
innocuous 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 during
syntheses to minimize or eliminate the formation of byproducts.
12.Minimize the potential for accidents: Design chemicals and their forms (solid, liquid, or gas) to
minimize the potential for chemical accidents including explosions, fires, and releases to the
environment.
1.
2.
Sustainable Chemistry Developments
Chemical products and processes should be designed to the highest level of this
hierarchy 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 many
academic labs across the country.
In recent history, the trend has been toward "microscale" methods; using
smaller quantities of reactants to minimize the impact.
In contrast, green chemistry focuses on using less toxic reactants in the first
place, thus reducing the need to use microscale methods. Students in a
green chemistry lab can use quantities more typical of an industrial
setting than their counterparts in a microscale lab. Finding realistic
solutions to environmental concerns in academic labs should prove to be a
boon to industry as they look for employees ready to meet the demands of the
future of science.
History OF Green Chemsitry:
Shortly after the passage of the Pollution Prevention Act of 1990, the Office of
Pollution Prevention and Toxics (OPPT) explored the idea of developing new or
improving existing chemical products and processes to make them less hazardous to
human health and the environment. In 1991, OPPT launched a model research
grants program called "Alternative Synthetic Pathways for Pollution Prevention". This
program provided unprecedented grants for research projects that include pollution
prevention in the design and synthesis of chemicals. In 1993, the program was
expanded to include other topics, such as greener solvents and safer chemicals, and
was renamed "Green Chemistry." Since then, the Green Chemistry Program has built
many collaborations with academia, industry, other government agencies, and nongovernment organizations to promote the use of chemistry for pollution prevention
through completely voluntary, non-regulatory partnerships.
Presidential Green Chemistry Challenge
In 1995, OPPT launched the Presidential Green Chemistry Challenge , a voluntary partnership to
support 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 source
while contributing to the competitiveness of the innovators. Nominations for awards are judged for
how well they meet the selection criteria: novelty, environmental and human health benefits, and
impact or applicability in industry.
The Awards provide a rich source of examples of how proactive design of chemical products and
processes benefit the triple bottom line and move our society towards sustainability.
Top of page
Goals
EPA's Green Chemistry Program promotes the research, development, and implementation of
innovative chemical technologies that accomplish pollution prevention in a scientifically sound and
cost-effective manner. To accomplish these goals, the Green Chemistry Program recognizes and
supports chemical technologies that reduce or eliminate the use or generation of hazardous
substances during the design, manufacture, and use of chemical products and processes. More
specifically, the Green Chemistry Program supports fundamental research in the area of
environmentally benign chemistry as well as a variety of educational activities, international
activities, conferences and meetings, and tool development, all through voluntary partnerships
with 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 two
term sequence, taught by Jim Hutchison and Ken Doxsee consisted of two sections with twelve students each. Additionally, three
teaching assistants, Marvin Warner, Scott Reed, and Brad Wan worked with the students in the lab and continue to optimize and
test new green laboratory experiments. For the 1999-00 year, the green lab will be expanded to a class of 30 students, to further
test the experiments, conduct monitoring of waste production and air monitoring.
One of the challenges in developing this course was developing new
laboratory experiments, as there are very few examples in current lab
manuals. Our criteria for identifying green experiments for this curriculum
were that each experiment:
Illustrates green chemical concepts (e.g. recycling, hazard
reduction, solvent reduction)
Teaches modern reaction chemistry and techniques
Complements the lecture course and provides a platform for
discussion of environmental issues in the classroom
Can be accomplished by students given the time (3 hours) and
material 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 focused
on secondary school needs, particularly in chemistry. Providing
practical experiences in chemistry is a priority because
chemicals are consumables, giving rise to high running costs
and significant hazard and environmental impact, if used on the
traditional scale. Furthermore there is a need to contribute to
life skills development for all future citizens, as regards
"chemical literacy". The microscience approach has met this
challenge very successfully and stimulated interest in its
application at other educational levels and in other sciences.
What is Microscale Chemistry?
How to maintain a pollution-free environment and how to handle chemical wastes
are subjects of increasing concern to all scientists, educators and the general
public.
The best way to succeed in this effort is by eliminating chemical waste at the
source. Reduction of chemical use to the minimum level at which experiments can
be effectively performed is known as Microscale Chemistry.
Microscale chemistry is an environmentally safe pollution prevention method of
performing chemical processes using small quantities of chemicals with out
compromising the quality and standard of chemical applications in education and
industry.
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 to
the use of chemicals. Microscale Chemistry is recognized as Smallscale Chemistry
by the International Union of Pure and Applied Chemistry

Training
Time
Economical
Teacher & Student
Environmental
The safety and security
Understands &
memorizes
Discipline
Hard work
Punctuality
Good conduct
Applications
Honesty
Patience
Practical
Application
Good manners
Responsiveness
memorizes
Understands
S.D 1
The teaching methods
for the strategies
continuity between the
teacher and student
Researcher
Scientism
and
theoretical
system
Scientific
experiments ,
practical system
Artistry proficiency
Handmade proficiency
Conscience collection
Thinking collection
Proficiency collection
Handmade collection
Ideological
proficiency Scientism
proficiency
S.D.1
Student
Showing the
quality in more
than ten
workshops and
Conferences
.
Time
Green Sciences
in Scientific and
research Training
Quality Triangle is designed
by the help of Dr.Hamed
Elwan
Continuous
Improvement
.
Qualit
y
Search Training and high
studies under the
supervison of Scientific
Research
Cost
Systemic entrance in
teaching and learning
sciences courses
Application
from Life
Experiment
Viewing
Scientific
Application
Deduction
Theoretical
Methodology
‫ا‬application
from Faith
NO2(g)
- NaCl
- H2O
NaNO2
+
- NaCl
- H2O
SO2(g)
Na2S2O3
- NaCl
- H2O
Na2SO3
+
+
+
HCl
+
- NaCl
Na2CO3
+
- H2O
- NaCl
NaHCO3
- H2O
FeS
- Na3F
- H2O
H2S(g)
Reference: scientific book coves the course of general basis of chemistry:
System of Green Chemistry Experiments in General Chemistry Basis
CO2(g)
Finding mole size from a gas under the standard conditions
2KClO4
23 mg
MnO2
2 KCl + 3 O2
Water size=resulted Oxygen=7.2
Designed by
Hassan Al Bare and Ali Masaud
Determination of Gas constant
2HCl
0.5 ml
12 ml
+
Mg
MgCl2
+
H2
1.13 mg
‫تصميم‬
‫حسن البار وعلى مسعود‬
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
2HCl
0.5 ml
1.13 mg
+ Mg
MgCl2 + H2
12 ml
‫تصميم‬
‫حسن البار وعلى مسعود‬
‫‪2005‬‬
‫تجارب توضيحية عن استراتيجية التدريب على إجراء‬
‫التجارب العملية باستعمال نظام علوم الميكروسكال‬
‫‪20‬‬
‫‪GREEN CHEMISTRY‬‬
‫صورة للجهاز المستخدم في التجربة‬
21
Determination of the Percent Composition and simplest formula
Microstand
Glass Fusion
Silicone tube
Syring
H 2O 2
Comboplate
.
O2
Lid 1
Comboplate
MnO2
Furnace
H2O absorber A
Mg(ClO4)2
Cyclohexane
Or ethylacetate
Or benzoic acid
A
CO2 absorber B
Finely divided
NaOH supported on
asbestos.
B
Inside the Comboplate wt. of H 2O and CO2 will get
them from the different the two beakers A & B
(contain the absorbers) before and after the
experiment.
OR
Zn + HCl
H2
Metal Oxide ………..
Continuous Improvement team that follows
up Teacher, Student, Supervisor and
Technician’s Performance
Learner
Technicians
Committee of
Training Following
Up
Teacher
Supervisor
Continuous Improvement
Team that followed to
Trainee
Technical Team for Training .........
Program of Micro Chem Green
Sciences
Comprehensive
Quality
Administration
Appraisal questionnaire of each experiment in the green scientific program
The 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 techniqu
e:
No
.
1
2
3
4
5
6
7
8
9
10
11
12
13
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15
Statement
The rate of suitability exp. at your system
order school
The easy in the run of exp.
The time of demonstrated exp. With
comparable traditional method
The rate of safety and security through the
exp. Running
The rate of pollution obtained from exp.
The rate of approach realization from the exp.
The rate of the significance technique for pupil
student
The chemical quantity used in the exp. With
other method techniques
The ability of the student to accept that exp.
The rate of newness their technique
The rate of positive action at the time of
running with your student civilized action ,
with insert.
Your insert. of laying lay this technique at your
school
The rate in the use of systematic technique for
the binding between the net results of exp .
and the theoretical system
The extent of your opinion for lute of exp.
Result with conclusion study system
The rate of the student assimilation for the
theoretical part in which its supported the
experiment
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easy
less
in
time
-
medium
-
Difficult
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Long
than
equal
Very
little
Medium
equivalent
Little
1
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Stron
gly
Normal
Refused
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