(By Dr. Ashaq Hussain Astt. Professor (Chemistry) Govt. P.G.College Bhaderwah)
"It is impossible to deny that Chemistry has played a major part in determining the nature of the modern world." - Linus Pauling.
Chemistry has played a key role in determining the nature of the modern world. While defining chemistry let us consider a traditional definition which states 'Chemistry is the science of matter which undergoes changes during chemical reaction'. But in reality chemistry goes beyond its traditional definitions. From the evolution of mankind itself, chemistry had a close connection with the daily acts of human beings. So we cannot deny the contribution of chemistry. Every matter is related to chemistry; even we human beings are made of chemicals. Almost all changes that we see around are means of chemical reactions.
Chemistry has improved our quality of life, and made thousands of products possible. Unfortunately, the very fact that every good thing has a bad side to it gives rise to the question, As there are two sides of a coin, chemistry if not properly used can become the cause of the 'death carrier' of the planet that we live in.
Thus this achievement has come at a price: our collective human health and the global environment are threatened .Our bodies are contaminated with a large number of synthetic industrial chemicals, many of which are known to be toxic and carcinogenic while others remain untested for their health effects. Many chemicals work their way up the food chain and circulate round the globe. However All in All, the Pros of Chemistry far outweigh the cons. The only thing that researchers have to care of is, misusing chemistry.Before going into the details one should know the famous quote of Albert Einstein, “The significant problems we face today cannot be solved at the same level of thinking we were at when we created them.” While some efforts are underway to overhaul chemicals policy, the focus is also on overhauling the way chemicals are designed from the outset. This is what Green Chemistry sets out to do.
What is Green Chemistry?
Green chemistry, also called sustainable chemistry, is a philosophy of chemical research and engineering that encourages the design of products and processes that minimize the use and generation of hazardous substances. The goal of green chemistry is to create better, safer chemicals while choosing the safest, most efficient ways to synthesize them and to reduce wastes. It aims to avoid problems before they happen. The focus is on minimizing the hazard and maximizing the efficiency of any chemical choice. Thus Green Chemistry is an innovative scientific movement aimed at replacing toxic chemicals with safe materials. It provides an overarching set of principles for chemists and others to develop products, processes and services that curb pollution, waste, and energy consumption.
Although Green Chemistry has been around for over a decade, however due to fuel prices rise, it is generating more interest from industries in search of sustainable alternatives to petroleum-based products and work processes that use a lot of energy.
The green chemistry program was begun shortly after the passage of the Pollution Prevention Act of 1990 and is the central focus of the environmental Protection Agency’s Design for the Environment Program. However, Green Chemistry was officially launched in 1998, when two US chemists, Dr Paul Anastas and Dr John Warner of the Green Chemistry Institute of the American Chemical Society published the “Twelve Principles of Green Chemistry.” These principles outline methods for designing energy-efficient processes for creating non-polluting products. The main concept of these principles is:
· the design of processes to maximize the amount of raw material that ends up in the product;
· the use of safe, environment-benign substances, including solvents, whenever possible;
· the design of energy efficient processes;
· the best form of waste disposal: not to create it in the first place.
The 12 principles are:
• Raw materials. Companies can change the materials that they use to manufacture chemicals. Instead of relying on petrochemicals, they can use renewable biomass feedstocks, develop new chemical building blocks based on biomass or copy chemicals that already exist naturally.
• Production. Manufacturers can achieve significant change in their production efficiency, costs and impacts by using alternative reaction pathways, solvents, catalysts, reactor technology and solvent less systems. In particular, they can gain dramatic decreases in energy use and waste output. Such changes are the most established green chemistry practices because of prior industry interest in pollution prevention.
• Products. Targeting products can help create green chemistry changes that propagate across the production system. Manufacturers can reformulate chemicals, or redesign consumer products or introduce new ones so that less toxic chemicals are incorporated into products.
• Energy:- The vast majority of the energy generated in the world today is from non-renewable sources that damage the environment. Green Chemistry will be essential in developing the alternatives for energy generation (photovoltaics, hydrogen, fuel cells, biobased fuels, etc.) as well as continue the path toward energy efficiency with catalysis and product design at the forefront.
• Global Change:- Concerns for climate change, oceanic temperature, stratospheric chemistry and global distillation can be addressed through the development and implementation of green chemistry technologies.
• Resource Depletion:-Due to the over utilization of non-renewable resources, natural resources are being depleted at an unsustainable rate. Fossil fuels are a central issue. Renewable resources (Biomass, Nanoscience & technology, Solar, Carbon dioxide, Chitin, Waste utilization etc) can be made increasingly viable technologically and economically through green chemistry.
• Food Supply:-While current food levels are sufficient, distribution is inadequate, Agricultural methods are unsustainable and the Future food production intensity is needed. The Green chemistry can address many food supply issues by supplying Pesticides which only affect target organisms and degrade to innocuous by-products and Fertilizers and fertilizer adjuvants that are designed to minimize usage while maximizing effectiveness.
The common example of utilization of Green chemistry is the Synthesis of Ibuprofen (analgesic, anti-inflammatory)
Environmental Advantages of BHC Synthesis of Ibuprofen
• Less waste
– greater atom economy
– catalytic versus stoichiometric reagents
– recycling, reuse, recovery of byproducts and reagents (acetic acid >99%; HF >99.9%)
– greater throughput (three steps versus five steps) and overall yield (virtually quantitative)
– Fewer auxiliary substances (solvents separation agents)
Another example of the difference between traditional chemistry and green chemistry is the use of petroleum. Today’s chemical industry relies almost entirely on non-renewable petroleum as the primary building block to create chemicals. This type of chemical production typically is very energy intensive, inefficient, and toxic—resulting in significant energy use, and generation of hazardous waste. One of the principles of green chemistry is to prioritize the use of alternative and renewable materials including the use of agricultural waste or biomass and non-food-related bio products.
In general, chemical reactions with these materials are significantly less hazardous than when conducted with petroleum products. Other principles focus on prevention of waste, less hazardous chemical syntheses, and designing safer chemicals including safer solvents. Others focus on the design of chemicals products to safely degrade in the environment and efficiency and simplicity in chemical processes.
Conclusion
Consumers and business purchasing departments can promote green chemistry by demanding safer, non-toxic products from manufacturers. This will help give a competitive advantage to those companies who screen the chemicals used in their products and demand safer substitutes from their suppliers. Such demand will also help increase the number of green chemistry courses in universities, training the next generation of chemists to consider life cycle impacts of the chemicals they design. To what degree the chemical industry is actually adopting green chemistry principles is unknown because some of the most innovative examples are proprietary. Researchers at Yale are identifying the barriers within the chemical industry that prevent or slow the adoption of green chemistry.13 Green chemistry awards help publicize the feasibility of green chemistry but much more needs to be done. Governments have a major role in adopting policies that promote green chemistry innovation and implementation in the commercial sector.
At the same time the chemical industry has a duty to integrate the principles of green chemistry into their manufacturing processes while product manufacturers and retailers have a responsibility to demand chemicals from their suppliers that have been tested and shown to be inherently safe. Green economic innovation for the 21st Century will require green chemistry Green Chemistry or environmentally benign chemistry is the design of chemical products and processes that eliminates the use or generation of substances hazardous to human health.
In the end we can say that Green chemistry is not a solution to all environmental problems But the most fundamental approach to preventing pollution.
"It is impossible to deny that Chemistry has played a major part in determining the nature of the modern world." - Linus Pauling.
Chemistry has played a key role in determining the nature of the modern world. While defining chemistry let us consider a traditional definition which states 'Chemistry is the science of matter which undergoes changes during chemical reaction'. But in reality chemistry goes beyond its traditional definitions. From the evolution of mankind itself, chemistry had a close connection with the daily acts of human beings. So we cannot deny the contribution of chemistry. Every matter is related to chemistry; even we human beings are made of chemicals. Almost all changes that we see around are means of chemical reactions.
Chemistry has improved our quality of life, and made thousands of products possible. Unfortunately, the very fact that every good thing has a bad side to it gives rise to the question, As there are two sides of a coin, chemistry if not properly used can become the cause of the 'death carrier' of the planet that we live in.
Thus this achievement has come at a price: our collective human health and the global environment are threatened .Our bodies are contaminated with a large number of synthetic industrial chemicals, many of which are known to be toxic and carcinogenic while others remain untested for their health effects. Many chemicals work their way up the food chain and circulate round the globe. However All in All, the Pros of Chemistry far outweigh the cons. The only thing that researchers have to care of is, misusing chemistry.Before going into the details one should know the famous quote of Albert Einstein, “The significant problems we face today cannot be solved at the same level of thinking we were at when we created them.” While some efforts are underway to overhaul chemicals policy, the focus is also on overhauling the way chemicals are designed from the outset. This is what Green Chemistry sets out to do.
What is Green Chemistry?
Green chemistry, also called sustainable chemistry, is a philosophy of chemical research and engineering that encourages the design of products and processes that minimize the use and generation of hazardous substances. The goal of green chemistry is to create better, safer chemicals while choosing the safest, most efficient ways to synthesize them and to reduce wastes. It aims to avoid problems before they happen. The focus is on minimizing the hazard and maximizing the efficiency of any chemical choice. Thus Green Chemistry is an innovative scientific movement aimed at replacing toxic chemicals with safe materials. It provides an overarching set of principles for chemists and others to develop products, processes and services that curb pollution, waste, and energy consumption.
Although Green Chemistry has been around for over a decade, however due to fuel prices rise, it is generating more interest from industries in search of sustainable alternatives to petroleum-based products and work processes that use a lot of energy.
The green chemistry program was begun shortly after the passage of the Pollution Prevention Act of 1990 and is the central focus of the environmental Protection Agency’s Design for the Environment Program. However, Green Chemistry was officially launched in 1998, when two US chemists, Dr Paul Anastas and Dr John Warner of the Green Chemistry Institute of the American Chemical Society published the “Twelve Principles of Green Chemistry.” These principles outline methods for designing energy-efficient processes for creating non-polluting products. The main concept of these principles is:
· the design of processes to maximize the amount of raw material that ends up in the product;
· the use of safe, environment-benign substances, including solvents, whenever possible;
· the design of energy efficient processes;
· the best form of waste disposal: not to create it in the first place.
The 12 principles are:
- 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 wherever 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 chosen to minimize potential for chemical accidents, including releases, explosions, and fires.
• Raw materials. Companies can change the materials that they use to manufacture chemicals. Instead of relying on petrochemicals, they can use renewable biomass feedstocks, develop new chemical building blocks based on biomass or copy chemicals that already exist naturally.
• Production. Manufacturers can achieve significant change in their production efficiency, costs and impacts by using alternative reaction pathways, solvents, catalysts, reactor technology and solvent less systems. In particular, they can gain dramatic decreases in energy use and waste output. Such changes are the most established green chemistry practices because of prior industry interest in pollution prevention.
• Products. Targeting products can help create green chemistry changes that propagate across the production system. Manufacturers can reformulate chemicals, or redesign consumer products or introduce new ones so that less toxic chemicals are incorporated into products.
• Energy:- The vast majority of the energy generated in the world today is from non-renewable sources that damage the environment. Green Chemistry will be essential in developing the alternatives for energy generation (photovoltaics, hydrogen, fuel cells, biobased fuels, etc.) as well as continue the path toward energy efficiency with catalysis and product design at the forefront.
• Global Change:- Concerns for climate change, oceanic temperature, stratospheric chemistry and global distillation can be addressed through the development and implementation of green chemistry technologies.
• Resource Depletion:-Due to the over utilization of non-renewable resources, natural resources are being depleted at an unsustainable rate. Fossil fuels are a central issue. Renewable resources (Biomass, Nanoscience & technology, Solar, Carbon dioxide, Chitin, Waste utilization etc) can be made increasingly viable technologically and economically through green chemistry.
• Food Supply:-While current food levels are sufficient, distribution is inadequate, Agricultural methods are unsustainable and the Future food production intensity is needed. The Green chemistry can address many food supply issues by supplying Pesticides which only affect target organisms and degrade to innocuous by-products and Fertilizers and fertilizer adjuvants that are designed to minimize usage while maximizing effectiveness.
The common example of utilization of Green chemistry is the Synthesis of Ibuprofen (analgesic, anti-inflammatory)
Environmental Advantages of BHC Synthesis of Ibuprofen
• Less waste
– greater atom economy
– catalytic versus stoichiometric reagents
– recycling, reuse, recovery of byproducts and reagents (acetic acid >99%; HF >99.9%)
– greater throughput (three steps versus five steps) and overall yield (virtually quantitative)
– Fewer auxiliary substances (solvents separation agents)
Another example of the difference between traditional chemistry and green chemistry is the use of petroleum. Today’s chemical industry relies almost entirely on non-renewable petroleum as the primary building block to create chemicals. This type of chemical production typically is very energy intensive, inefficient, and toxic—resulting in significant energy use, and generation of hazardous waste. One of the principles of green chemistry is to prioritize the use of alternative and renewable materials including the use of agricultural waste or biomass and non-food-related bio products.
In general, chemical reactions with these materials are significantly less hazardous than when conducted with petroleum products. Other principles focus on prevention of waste, less hazardous chemical syntheses, and designing safer chemicals including safer solvents. Others focus on the design of chemicals products to safely degrade in the environment and efficiency and simplicity in chemical processes.
Conclusion
Consumers and business purchasing departments can promote green chemistry by demanding safer, non-toxic products from manufacturers. This will help give a competitive advantage to those companies who screen the chemicals used in their products and demand safer substitutes from their suppliers. Such demand will also help increase the number of green chemistry courses in universities, training the next generation of chemists to consider life cycle impacts of the chemicals they design. To what degree the chemical industry is actually adopting green chemistry principles is unknown because some of the most innovative examples are proprietary. Researchers at Yale are identifying the barriers within the chemical industry that prevent or slow the adoption of green chemistry.13 Green chemistry awards help publicize the feasibility of green chemistry but much more needs to be done. Governments have a major role in adopting policies that promote green chemistry innovation and implementation in the commercial sector.
At the same time the chemical industry has a duty to integrate the principles of green chemistry into their manufacturing processes while product manufacturers and retailers have a responsibility to demand chemicals from their suppliers that have been tested and shown to be inherently safe. Green economic innovation for the 21st Century will require green chemistry Green Chemistry or environmentally benign chemistry is the design of chemical products and processes that eliminates the use or generation of substances hazardous to human health.
In the end we can say that Green chemistry is not a solution to all environmental problems But the most fundamental approach to preventing pollution.
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