Ozone depletion potential, life cycle

Manufacturing processes for sustainability can be optimized in the context of life cycle analysis (Shoimard and Hiew 2000). It involves definition of the process boundaries and quantifiable sustainability impacts in the form of established metrics, incorporated into process design and optimization. It has been applied to determining waste treatment options, abatement of pollution, and designing the optimal recipe of solvents. Impact indices, such as ozone depletion potential to human toxicity and eco-toxicity, developed by the EPA, can be used. This method has been applied in a methyl ethyl ketone production plant to determine the effect of recycling on the enviromnent (Shonnard and Hiew 2000). 

Life-cycle assessment when carried ont according to the ISO rules has shown its ability to deliver data for certain more global environmental compartments like the impact potential on saving of resonrces, global warming potential, acidification, ozone depletion, and the like. It nsnally does not cover local effects such as noise or smell and hazardons snbstances. Here risk assessment or other methodologies are needed. The evalnation of effects regarding human toxicity is hampered by a lack of sufficient data and by a still undecided question of data evaluation. Thns, life-cycle analysis is a nseful tool but not the only answer to all enviromnental aspects. 

The LCA study of ethanol focused on the evaluation of (GHG) emissions. Meanwhile, Life Cycle Impact Assessment (LCIA) studied the impacts (eg, global warming potential, ozone depletion, acidification potential) resulting from the LCI study. Finally, depending on the results obtained in the LCI and/or LCIA, many suggestions and recommendations can be offered. GHG emissions of biofuels are expressed per MJ of unit output. 

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