Discuss the principles and applications of distillation in chemical engineering processes, focusing on its role in separating liquid mixtures based on differences in volatility. Explore the design and operation of distillation columns, including tray and packed column configurations. Highlight key factors influencing separation efficiency, such as reflux ratio, tray efficiency, and column diameter. Provide examples of industrial distillation processes and their significance in producing pure chemicals, fuels, and pharmaceuticals.