Chemical engineers run chemical plants for maximum efficiency. Thermodynamics is an ever present tool for maximizing production with minimum energy usage. All chemical engineering programs include multiple discussions of thermodynamics at all levels.

An early successful application of thermodynamics to chemical engineering was the Haber process for production of ammonia. While this example is frequently noted with discussions of equilibrium and LeChatelier's principle, thermodynamic calculations make predictions quantitative. The Gibb's free energy calculations under non-standard conditions predict conditions for spontaneity. This process still produces millions of tons of ammonia every year.