Assessment of the Sustainability-Potential of Adipic Acid Processes

The concept of sustainability-potential has been demonstrated to be a valuable tool for considering alternate chemical process schemes.  This hierarchical approach is a generalization of the notion of gross profit potential (GPP).  As such, it permits assessment of the technoeconomic, environmental, and societal impacts of a process in the early stages of its design.  In the present work, the sustainability-potential of adipic acid production from a biorenewable feedstock will be compared with that of conventional adipic acid processes based upon petroleum feedstocks.  Consideration of the gross available exergy dissipation for the conventional route (-983 kJ/mole) is much more negative than that for the biorenewable approach (-146 kJ/mole).  As such the biorenewable approach is more sustainable from a thermodynamic standpoint.  The gross profit potential shows the opposite trend.  The GPP for the biorenewable approach is quite low while the conventional adipic acid process has a positive GPP.  Arriving at a toxicity index is a much more subjective process.  Using measured and estimated values for the fathead minnow LC₅₀ as a toxicity index, the two processes are roughly equivalent.  Alternate indices for environmental and health considerations will be discussed.