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GREEN CHEMISTRY GREEN CHEMISTRY PREVENTING POLLUTION SUSTAINING THE EARTHGREEN CHEMISTRY DEFINITION Green Chemistry is the utilisation 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 .

GREEN CHEMISTRY IS ABOUTWaste Minimisation at SourceUse of Catalysts in place of ReagentsUsing Non-Toxic ReagentsUse of Renewable ResourcesImproved Atom EfficiencyUse of Solvent Free or Recyclable Environmentally Benign Solvent systems

2What is the atom economy for making hydrogen by reacting coal with steam ? The other product is carbon dioxide.Write the balanced equation:C(s) + 2H2O(g) CO2(g) + 2H2(g)

C(s) + 2H2O(g) CO2(g) + 2H2(g) 12 2 18 44 2 2 total mass of products = 44 + 4 = 48g (note that this is the same as the reactants: 12 + 36 = 48g) mass of desired product (H2) = 4g% atom economy = 4 48 100 = 8.3%

This process has a low atom economy and is therefore an inefficient way to make hydrogen. It also uses a non-renewable resource: coal.

PRINCIPLES OF GREEN CHEMISTRYThe environment and human health.A stable economy that uses energy and resources efficiently.Social and political systems that lead to a just society.

IN A SUSTAINABLE CIVILIZATIONTechnologies used for production of needed goods are not harmful to the environment or to human health.Renewable resources (such as plant-based substances or solar energy) are used rather than those, like fossil fuels, that will eventually run out.

IN A SUSTAINABLE CIVILIZATIONManufacturing processes are either designed so as not to produce waste products, OR Waste products are recycled or biodegradable.

GREEN CHEMISTRY WORKS TOWARD SUSTAINABILITY BY:Making chemical products that do not harm either our health or the environment,Using industrial processes that reduce or eliminate hazardous chemicals, andDesigning more efficient processes that minimize the production of waste materials.

Examples of Green ChemistryNew syntheses of Ibuprofen and Zoloft.Integrated circuit production.Removing Arsenic and Chromate from pressure treated wood.Many new pesticides.New oxidants for bleaching paper and disinfecting water.Getting the lead out of automobile paints.Recyclable carpeting.Biodegradable polymers from renewable resources.

SYNTHESIS OF IBUPROFENIbuprofen is a popular over-the-counter drug that has pain relief and anti-inflammatory properties. It was originally developed in the 1960s by the Boots Company of England. The Boots synthesis of Ibuprofen involved a six-step process that generated millions of pounds of unwanted waste This became known as the Brown process due to reactants of the process not being incorporated into the product because of poor atom utilization.

The solution to this problem was developed by the BHC Company in 1991. They implemented the green synthesis of Ibuprofen, which only required three steps. This process also incorporated most of the reactants into the final product, reducing or eliminating most of the waste by-products. The switch from the Boots process to the BHC process has resulted in a more efficient creation of Ibuprofen.

IN SUMMARY,GREEN CHEMISTRY ISScientifically sound,Cost effective, andLeads toward a sustainable civilization.