绿色化学与化工导论Chapter 1 introduction Production costs Figure Production costs for speciality chemicals. The Coy thought of as being dirty (oil refining & bulk chemical production) are relatively clean - they need to be since margins per Kg are low. Newer industries with higher profit margins and employing more complex chemistry produce much more waste relatively. Industry sector Product tonnage By-product weight / product weight Oil Refining 106 - 108 < Bulk Chemicals 104 - 106 1 - 5 Fine Chemicals 102 - 104 5 – 50+ Pharmaceuticals 10 - 103 25 - 100+ Environmental quotient (EQ) E-----Environmental factor Q-----The extent of hazardousness of the waste to the environment obtained from the performance of the waste in the environment. EQ＝E×Q The E factor just gives the ratio of the waste and the target product. But the environmental pollution is strongly associated with the harmful performance of the waste. Energy Efficiency Table Global ‘lost work’ in major chemical processes Process Theoretical work potential (kJ·mol-1 final product) Raw materials Final producta Thermodynamic efficiency (%) Natural gas + air → methanol 1136 717 63 Natural gas + air → hydrogen 409 236 58 Ammonia (from natural gas + air) → nitric acid 995 43 4 Copper ore → copper 1537 130 9 Bauxite →aluminium 4703 888 19 a Excludes any ‘steam credit’. Energy efficiency via ‘lost work’ Biomass utilisation Figure Biomass utilisation in 2040. Biomass utilisation Table From fossil to green Energy source Percentage of energy sources 1990a 2040b Oil 38 17 Coal 20 18 Gas 16 14 Biomass 16 19 Hydro 5 5 Nuclear 5 6 Solar — 14 Wind — 7 Based on an energy consumption of a ×1020J; b 1×1021J. We seek to satisfy our need and not our greed life-cycle assessment The life-cycle of a product can be considered as: Pre-manufacturing (materials acquisition) ↓ Manufacturing (processin
