Sustainability & efficiency (sustainable development, sustainability methods & metrics, thermodynamic approach to sustainability of efficiency). Thermodynamic Analysis of process (Mass & energy rate balances for a steady flow process – 1^st law of thermodynamics, quality of energy & materials, entropy & 2^nd law of thermodynamics, entropy production, entropy rate balance for a steady flow process, maximum work obtainable from a steady flow process). Exergy concept (Defining exergy, exergy reference environment, exergy versus energy, exergy of work & heat transfer, exergy of a stream of matter, physical exergy, chemical exergy). Exergetic evaluation of process & technologies (Exergy rate balance for a steady flow process, internal & external exergy losses, exergetic efficiency performance, Economic & Ecological aspects of exergy). Renewability of biofuels (Application of cumulative exergy consumption of biofuels production, renewability indicators).