GREEN CHEMISTRY is a program of developing new chemical products and chemical processes or making improvements in the already existing compounds and processes so as to make them less harmful to human death and environment. Green chemistry uses the database information about the toxic and hazardous properties of certain in order to fully evaluate their positive and negative impact. The non availability of such data in the previous years posed problems to the chemists for evaluating consequences of the chemical substance being synthesis and green chemistry tries to find the solution of these problems.
FATHER Of Green CHEMISTRY:
PAUL.T.ANASTAS the father of green chemistry. They for the first time in 1991 coined the term green chemistry. Recently Paul T. Anastasio the Director of Yale University’s for Green Chemistry and Green Engineering. 15 years ago in 1990 the concept of green chemistry was established at the Environment Protection Agency . It was a response to the Pollution Prevention Act of 1990
When we start talking about GREEN CHEMISTRY many of us relate Green chemistry to the branch of science involving plants. However, it is nothing to do with the chemistry of plants. In fact, it relate to the program of alternative synthetic pathways for prevention of environmental pollution. The expression green chemistry was used by scientists in 1902 after the formation of Pollution Prevention Act 1990.
GREEN CHEMISTRY is simply a way of utilizing the existing knowledge and principles of Chemistry and other sciences to reduce the harmful impact on environment due to the compounds.
In the period of 1990’s a variety of ideas and research efforts (such as atom economy and catalysis ) emerged Green Chemistry .
Green chemistry is also known as “clean” and “sustainable” chemistry .
In 1962 a book Silent spring was written by Rachel Carson . It was a scientific book it talked about the devastation that certain chemical had on local ecosystem. The book served as wake up call for thee Public as well as the scientist and inspired the Morgen environmental movement . After this the congress noticed the importance and passed the National Environment Policy Act in 1969. This was The first step taken for the environment.
12 Principles of Green Chemistry
“ It is better to prevent waste than to treat or clean up waste after it is formed”.
- Atom Economy
“Synthetic method should be designed to maximize the incorporation of all materials used in process into the final products”.
- Less Hazardous Chemical Syntheses
“Whenever practicable, synthetic methodologies should be designed to use and generate substance that litter or no toxicity to human health and environment”
- Designing Safer Chemicals
“Chemical products should be designed to preserve Efficacy of function while reducing toxicity”.
- Safer Solvents and Auxiliaries
“ The use of auxiliary substance should be made unnecessary where possible and innocuous when used”.
- Reduce Derivatives
“Reduce derivatives unnecessary derivatives should be avoided whenever possible”.
“Catalytic reagents are superior to chemical reagents”
Use of a catalyst facilities transformation without the catalyst being consumed in the reaction and without incorporated in the final product.
- Design for Degradation
“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”.
- 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 substance”.
“Checking the Progress of chemical reaction as it happens”.
- Inherently Safer Chemistry for Accident Prevention
“Substance and the form of a substance used in a chemical process should be chosen to low potential for chemical accidents, including releases explosions, and fires”.
Design for Energy Efficiency
“Energy requirements should be recognized for their environmental and economic impacts and should be minimized. Synthetic method should be conducted at ambient temperature and pressure”.
Use of Renewable Feed stocks
“ A raw material or feed stock are often made from agricultural products are the waste of the other processes depleting feed stock are made from fossil fuels or are mined.
APPLICATION OF GREEN CHEMISTRY:
Green Chemistry In industry
- Development of dense-phase carbon dioxide.
Dense-phase Carbon dioxide has been characteristics. This super critical Carbon dioxide is wonderful material which has the ability to clean everything from the plutonium pits to semiconductor wafer as well as clothes. It can also be used as recyclable solvent and finds number of applications in food industry. Future possible uses of the Carbon dioxide include making cement stronger and also in reducing pollution emission from coal plants.
- Development of fuel cells for cellular phones which can last full life time of thee phones. These cells are based on methanol-oxygen fuels.
- Development of new method for synthesizing ibuprofen in 99 Percent yield, avoiding the use of large quantities of solvents and waste associated with traditional methods.
- Development of a safer marine compound sea-nine that degrades more rapidly than organised which persist in Marin environment and cause pollution problems.
- Development of a method for catalytic hydrogenation of diethanolamine. The new Friendly herbicide in a less dangerous way. This technology represents a major break through because it avoids the use of cyanide and formaldehyde.
GREEN CHEMISTRY IN Daily LIFE:
- Dry Cleaning of clothes
1,1,2,2-Tetrachloroethane was earlier used as solvent for dry cleaning clothes. The compound contaminates the ground water and is also a suspected carcinogen. Now a days, Carbon dioxide along with suitable detergent is used for dry cleaning in place of 1,1,2,2-Tetrachloroethane Replacement of hydrogenated solvent Carbon dioxide will result in less harm of ground water.
- Bleaching of paper and clothes
Chlorine gas was used earlier for bleaching of the paper. These days, hydrogen peroxide with some Suitable catalyst is used. Hydrogen peroxide is also used for the purpose of bleaching of clothes in the Laundry processes, which gives better results and makes use of lesser amount of water.
GREEN CHEMISTRY IN Agriculture:
Agriculture is the one of the most important things for humans.It plays an important role in the field of agriculture. Green chemistry principle are mostly related to the manufacturing part of the agriculture the pesticide, fertilizers should be non-toxic and should not harm the agriculture by any means And they also not harm humans and environment. There are many ways by which agriculture can be protected by green chemistry like:
- Minimise the risk of pesticides
- Using suitable fertilizer
- Maintain the variety
- Energy efficiency in the chemicals industry
Barriers of GREEN CHEMISTRY IN INDIA:
1: Availability of green technologies
2: Scale-up and commercial
3: Connecting green chemistry solution providers to industry
4:Understanding of basics of green principle
5: Green chemistry is costly, complex and not viable for SME?
6: Regulatory hurdles
Future aspects of green chemistry:
As we know green chemistry plays very important role for environment. In India present day also there are places where green chemistry should be applied but due to many reasons . In future
Green chemistry should be used there are many of the reasons
- Results in healthier living conditions
- Is economical and profitable
- Encourages creativity in the world of chemistry
- Is healthy for the environment.