"Explain the thermodynamic principles governing the separation processes in distillation columns, focusing on the factors influencing efficiency and energy consumption. Analyze the role of equilibrium stages, reflux ratio, and tray design in achieving optimal separation efficiency. Furthermore, discuss the impact of operating parameters such as temperature, pressure, and feed composition on the performance of distillation columns. Finally, evaluate emerging technologies such as reactive distillation and membrane distillation in enhancing the sustainability and effectiveness of separation processes."