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Martyn Poliakoff www.nottingham.ac.uk/supercritical.

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Presentation on theme: "Martyn Poliakoff www.nottingham.ac.uk/supercritical."— Presentation transcript:

1 Martyn Poliakoff

2 China Cup

3 Paper Cup

4 Polystyrene Cup

5 Which is best for the Environment? ChinaPaperPolystyene

6 Coffee Cups - Manufacture China – most energy to make Polystyrene – made from oil Paper – made from wood, messy process Cost of Energy varies

7 Coffee Cups- Use Polystyrene – use once Paper – use once China – multi-use BUT needs washing (hot water, detergent)

8 Coffee Cups- Verdict You have to use a china cup 1000 times before it is environmentally better than Polystyrene

9 Coffee Cups - Disposal China – landfill Polystyrene – landfill (125 times better) Paper – can be composted – generates CH 4 (greenhouse effect)

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15 One of the main problems in chemical manufacture is the generation/disposal of (toxic) waste

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17 Environmental acceptability: the E Factor Industrytons/yr E Oil refining ca. 0.1 Bulk Chemicals < Fine Chemicals Pharmaceuticals Roger A. Sheldon “Consider the Environmental Quotient” ChemTech, 1994, March, page 38. kgwaste/kgproduct

18 Roger Sheldon

19 Manufacture of Terephthalic Acid 26 Mtons per year world-wide 500,000 tons per year per plant CH 3 COOH O2O2 Catalyst

20 DuPont (former ICI) – Wilton Manufacturing Terephthalic Acid

21 Why not make fibres from Sheep?

22 Fibre from Sheep 1 Sheep produces 3.5 kg wool/ year 500,000 tons of wool need 10 8 sheep 10 sheep need 1 acre of land 10 8 sheep need 10 7 acres (640 acres = 1 square mile) 10 8 sheep need 15,625 square miles

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24 Fibre Production Sheep need 15,625 square miles 1 TA plant needs 25 acres

25 What is Green Chemistry? Carrying out chemical activities (design, manufacture, use and disposal) such that hazardous substances will not be used or generated

26 Assessing Risk Risk = Hazard x Exposure What we do now Limit Exposure  Acceptable Risk Green Chemistry if Hazard = 0  Risk = 0

27 Areas of Green Chemistry New reactions New catalysts Alternative Feedstocks Safer Solvents

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29 Most solvents are Volatile Organic Compounds Fire / explosion hazards VOC emissions  atmospheric pollution Disposal / recycle  environmental pollution Solvents: the problems

30 Fork Lift +Toluene  ‘Big Bang’

31 No solvent Water Ionic Liquids Supercritical Fluids Solvents: Alternatives

32 Supercritical Fluids Gases e.g. CO 2, C 2 H 4, H 2 O compressed until they are nearly as dense as liquids SCFs can dissolve solids solubility increases with density (applied pressure)

33 Decaffeination in scCO 2 Well established commercially

34 Greener Hydrogenation + H2H2 Catalyst Solvent? Use Supercritical CO 2 CO 2 compressed until it is nearly as dense as a liquid ca. 200 atm

35 Continuous Supercritical Hydrogenation

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38 Hydrogenation of Isophorone O Pd Deloxan® 100 bar, scCO °C + H 2 O scCO 2 - quantitative, no by-products The product & by-products have similar boiling points Conventional process requires an expensive downstream separation

39 Dr Stephen Ross Thomas Swan & Co Ltd

40 HeaterSub-cooler Hydraulic Power Unit CO 2 (liq) from Tank Work Tank Condenser Separator Pump Unit Products Reactor Reactants Flow diagram

41 continuous multipurpose 1000 ton p.a. scCO 2 Chemical Plant

42 The First Product! OO

43 Isophorone Hydrogenation Product of saleable quality without downstream purification Optimized conditions: almost identical for lab (5 mL) and plant (1000 tons p.a.)

44 Taking Green Chemistry to Developing Countries

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49 Sugar Cane

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51 Is it silly to make polymers out of sugar cane? Sugar cane is grown in huge amounts It grows where there is little oil There is a surplus The farmers cannot sell all of it No!!!

52 Sugar Cane

53 How to do it? “To make a bag from sugar needs new Chemistry” 2 nd July, 2003

54 Polymers from Carbohydrate Microorganisms eat carbohydrate They store energy as a polymer Polymer is easily harvested Waste is recycled. Dr Isao Noda, Procter & Gamble

55 P & G NODAX TM Polymer from carbohydrate

56 Coffee Cups from Waste Carbohydrate Cups for US Navy Can be made on existing machines Composts in 2 days!

57 Green Chemistry: What Now? 15 years old – growing fast Spreading all over the world Increasing industrial interest Needs lots of new ideas

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59 Live on the Web!! fusion.com/kongress /costday2004/http://www.meta- fusion.com/kongress /costday2004/


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