Quantifying technological aspects of process sustainability: a thermodynamic approach

S. Lems, H.J. van der Kooi, J. de Swaan Arons;

Thermodynamic analysis has greatly helped to
compare and to improve the energy efficiency of all kinds
of technological processes, and recently we have also attempted
to analyse some important biochemical processes
under intracellular conditions. This work has pointed to
some key strategies on sustainable process operation, such
as the exceptionally high thermodynamic efficiencies of
chemical and solar energy conversion in living cells.From
this it was expected that the sustainability strategies of
specific biochemical processes and those of the ecosphere
as a whole could be of guidance to current technological
processes, especially now that there is a growing demand
from government and industry to effectively deal with
sustainability aspects in process analysis. Our focus on this
issue has led to methodologies to quantify technological
aspects of sustainability by making use of thermodynamic
principles. Three indicators were constructed to express
three technological aspects of process sustainability. First,
an indicator for the sustainability of resource utilization
considers the thermodynamic input and the availability
the resources used in the process. Secondly, an efficiency
indicator focuses on the conversion and loss of thermodynamic
quantities in the process itself. Thirdly, an indicator
for environmental compatibility takes into account
the thermodynamic input required to prevent possible
negative side effects of the process, such as global warming
or water pollution. The three indicators are used to reflect
on (un)sustainable characteristics of current technological
processes compared to biochemical processes. Finally, we
address the drawbacks of combining indicator values to
express overall sustainability.