Implications of Thermodynamics for Sustainability

This chapter describes and demonstrates the role that thermodynamics can play in assessing the sustainability of technological activities and in improving their design. Since thermodynamics governs the behavior of all systems, it can play a crucial role in understanding fundamental physical limits of technologies and for quantifying the contribution of resources. The concept of exergy captures the first and second laws of thermodynamics. Since exergy is the common currency that flows and gets transformed in industrial and ecological systems, it allows the joint analysis of industrial and ecological systems. This insight permits accounting of the role of ecosystem goods and services in supporting human activities. Since ecosystems are critical to sustainability, accounting for their role must be a part of all methods aimed toward the analysis and design of sustainable systems. Thermodynamics provides a scientifically rigorous approach for meeting this challenge. In addition, exergy analysis of industrial processes and life cycles helps in identifying areas of maximum resource inefficiency and opportunities for improvement. This approach complements the insight obtained from assessing the impact of emissions. Case studies based on the life cycle of biofuels and nanomanufacturing are used to demonstrate the important role that thermodynamics can play in sustainability engineering.

Keywords: Thermodynamics, first law, second law, Gibbs free energy, Exergy, Energy analysis, Energy return on investment, Energy quality, Cumulative exergy consumption, Transformity, Emergy, Biofuels, Nanotechnology.