"How does the application of thermodynamics, kinetics, and transport phenomena theory in chemical engineering contribute to the understanding and optimization of chemical processes? Furthermore, how do theoretical frameworks like reaction kinetics aid in designing efficient reactors, while transport phenomena theories facilitate the design of optimal separation processes? Additionally, how does the integration of molecular$-$level insights, such as quantum mechanics principles in material design and computational fluid dynamics in reactor modeling, enhance the efficiency and sustainability of chemical engineering processes? Lastly, how do advancements in theoretical frameworks continually shape the innovation and evolution of chemical engineering practices?"