綠色化學(xué)slideworldgreenchemistryppt課件

1、GREEN 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

2、 of ReagentsUsing Non-Toxic ReagentsUse of Renewable ResourcesImproved Atom EfficiencyUse of Solvent Free or Recyclable Environmentally Benign Solvent systems Green Chemistry Is About. CostWasteMaterialsHazardRisk Energy Chemistry is undeniably a very prominent part of our daily lives. Chemical deve

3、lopments also bring new environmental problems and harmful unexpected side effects, which result in the need for greener chemical products. A famous example is the pesticide DDT.Why do we need Green Chemistry ? Green chemistry looks at pollution prevention on the molecular scale and is an extremely

4、important area of Chemistry due to the importance of Chemistry in our world today and the implications it can show on our environment. The Green Chemistry program supports the invention of more environmentally friendly chemical processes which reduce or even eliminate the generation of hazardous sub

5、stances. This program works very closely with the twelve principles of Green Chemistry.1. PreventionIt is better to prevent waste than to treat or clean up waste after it has been created.2. Atom EconomySynthetic methods should be designed to maximise the incorporation of all materialsused in the pr

6、ocess into the final product.3. Less Hazardous Chemical SynthesisWherever practicable, synthetic methods should be designed to use and generatesubstances that possess little or no toxicity to people or the environment.4. Designing Safer ChemicalsChemical products should be designed to effect their d

7、esired function while minimisingtheir toxicity.5. Safer Solvents and AuxiliariesThe use of auxiliary substances (e.g., solvents or separation agents) should be madeunnecessary whenever possible and innocuous when used.6. Design for Energy EfficiencyEnergy requirements of chemical processes should be

8、 recognised for their environmentaland economic impacts and should be minimised. If possible, synthetic methods should beconducted at ambient temperature and pressure.The 12 Principles of Green Chemistry (1-6)7 Use of Renewable FeedstocksA raw material or feedstock should be renewable rather than de

9、pleting whenever technically and economically practicable.8 Reduce DerivativesUnnecessary derivatization (use of blocking groups, protection/de-protection, and temporary modification of physical/chemical processes) should be minimised or avoided if possible, because such steps require additional rea

10、gents and can generate waste.9 CatalysisCatalytic reagents (as selective as possible) are superior to stoichiometric reagents.10 Design for DegradationChemical products should be designed so that at the end of their function they break down into innocuous degradation products and do not persist in t

11、he environment.11 Real-time Analysis for Pollution PreventionAnalytical methodologies need to be further developed to allow for real-time, in-process monitoring and control prior to the formation of hazardous substances.12 Inherently Safer Chemistry for Accident PreventionSubstances and the form of

12、a substance used in a chemical process should be chosen to minimise the potential for chemical accidents, including releases, explosions, and fires.The 12 Principles of Green Chemistry (7-12)“It is better to prevent waste than to treat or cleanup waste after it is formed”ChemicalChemicalProcessProce

13、ssClassic Route to IbuprofenAc2OAlCl3COCH3HCl, AcOH, Al WasteClCH2CO2EtNaOEtOEtO2CHClH2O / H+OHCAcOHNH2OHOHNNH2O / H+HO2CNH3Hoechst Route To IbuprofenOHFAcOHAc2OH2 / NiOHCO, PdHO2C“The use of auxiliary substances (e.g. solvents,separation agents, etc.) should be made unnecessarywherever possible, an

14、d innocuous when used”“Energy requirements should be recognized for their environmental impacts and should be minimized.Synthetic methods should be conducted at ambientpressure and temperature”HeatingCoolingStirringDistillationCompressionPumping SeparationEnergy Requirement(electricity)Burn fossil f

15、uelCO2 toatmosphereGLOBAL WARMING“A raw material of feedstock should be renewablerather than depleting wherever technically andeconomically practical”Non-renewableRenewableResource Depletion Renewable resources can be made increasingly viable technologically and economically through green chemistry.

16、BiomassNanoscienceSolarCarbondioxideWaste utilizationPoly lactic acid (PLA) for plastics productionPolyhydroxyalkanoates (PHAs) Energy Global Change Resource Depletion Food Supply Toxics in the EnvironmentThe major uses of GREEN CHEMISTRYEnergyuThe vast majority of the energy generated in the world

17、today is from non-renewable sources that damage the environment.uCarbon dioxideu Depletion of Ozone layer u Effects of mining, drilling, etcu ToxicsEnergyuGreen Chemistry will be essential inu developing the alternatives for energy generation (photovoltaics, hydrogen, fuel cells, biobased fuels, etc

18、.) as well as u 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

19、 technologies.Resource DepletionuDue to the over utilization of non-renewable resources, natural resources are being depleted at an unsustainable rate. uFossil fuels are a central issue.Resource DepletionuRenewable resources can be made increasingly viable technologically and economically through gr

20、een chemistry.u Biomassu Nanoscience & technologyu Solaru Carbon dioxideu Chitinu Waste utilizationFood SupplyuWhile current food levels are sufficient, distribution is inadequate u Agricultural methods are unsustainableu Future food production intensity is needed.u Green chemistry can address m

21、any food supply issuesFood SupplyuGreen chemistry is developing:u Pesticides which only affect target organisms and degrade to innocuous by-products.u Fertilizers and fertilizer adjuvants that are designed to minimize usage while maximizing effectiveness.u Methods of using agricultural wastes for beneficial and profitable uses.Toxics in the EnvironmentuSubstances that a