Python Notes for mca i year students osmania university.docx
Green chemistry - english version
1. Avanti
• It is better to prevent waste than to treat or clean up waste after it is formed.
• Synthetic methods should be designed to maximize the incorporation of all materials used in the process
into the final product.
• Wherever practicable, synthetic methodologies should be designed to use and generate substances that
possess little or no toxicity to human health and the environment.
• Chemical products should be designed to preserve efficacy of function while reducing toxicity.
• The use of auxiliary substances (e.g. solvents, separation agents, etc) should be made unnecessary
wherever possible and innocuous when used.
• Energy requirements should be recognized for their environmental and economic impacts and should be
minimized. Synthetic methods should be conducted at ambient temperature and pressure.
• A raw material or feedstock should be renewable rather than depleting whatever technically and
economically practicable
• Reduce derivatives – Unnecessary derivatization (blocking group, protection/deprotection, temporary
modification) should be avoided whenever possible.
• Catalytic reagents (as selective as possible) are superior to stoichiometric reagents.
• Chemical products should be designed so that at the end of their function they do not persist in the
environment and break down into innocuous degradation products.
• Analytical methodologies need to be further developed to allow for real-time, in-process monitoring and
control prior to the formation of hazardous substances.
• Substances and the form of a substance used in a chemical process should be choosen to minimize
potential for chemical accidents, including releases, explosions and fires.
2. Areas of Green Chemistry
Over 12 principles of green chemistry the OCSE (Organization Internazional for the Coperation
and Economic Development) has produced in a conference, held in Venezia, in October of
1998 (approved in Parigi in 1999) , a text on the 7 areas of Green Chemistry:
1) Use of recycled or renewable materials.
2)Use of harmless reagents
3)Use natural proces
4)Use alternative solvents
5)Design chemical compounds more sure
6)Development of alternative reaction conditions
7)Minimization of the consumption of energy
Indietro Avanti
3. Use of recycled or renewable
materials:
• This area of green chemistry find and use
renewable materials.
Renewable resource is a resource that can be
produced before it run out. The oils isn’t a
renewable resource because it taken millions
years to produce it. The biomass are
renewable materials results with the fast
forming.
Indietro Avanti
4. Use of harmless reagents
• In this case the modern science search new
advantageous methods for example serarch
reagent less polluting and catalysts more
selective.
The oxidation reactions that use air are too
fast or too lens and they aren’t selective. The
science search good reagent as water peroxide
or pure oxygen with selective catalysts.
Indietro Avanti
5. Use natural proces
• This area study the utilization of biological proces
for get renewable energy without polluting the
environment(because are biodegradable
substances). Also there is an energy and
resourcess saving.
The biosynthetic reactions are low consumption
of water, energy and limited emissions of CO2.
The natural proces are used for the production of
biofuel using waste products.
Indietro Avanti
6. Use alternative solvents
• This field is studied new alternative to
solvents more invasive for protection the
enviroment.
There are alternative to these solvents, for
example use water when is possible. Another
alternative is use harmless products
(water,CO2), in the supercritical phase
(pressure and temperature).
Indietro Avanti
7. Design chemical compounds more
sure
• This search with modern machines model the
molecules, or eliminate secondary products of
reaction dangerous for the organism.
You can do this if the molecules don’t change
it reactive features.
Indietro Avanti
8. Development of alternative reaction
conditions
• In this proces for increase the speed it use the
catalysts.
It use microonde or electromagnetic waves for
increase the speed.
According to the principe of “atom economy”,
it should eliminate the secondary products.
Indietro Avanti
9. Minimization of the consumption of
energy
• This field study new ways for reduce energy
for reaction.
Use of catalysts or solvents , it helps to save
energy.
Reduce consumption of energy for reduce
pollution.
Indietro Avanti