Distillation Troubleshooting. Reflux and Intermediate Feed Inlets for Tray Columns. Reflux and Intermediate Feed Distribution and Liquid Redistribution in Packed Towers. Bottom Section and Column Outlets. Gravity Lines. Instrument, and Access Connections. Tray and Downcomer Layout. Mechanical Requirements for Trays. Internals Unique to Packed Columns. Distillation Overpressure Relief. Column Assembly and Preparation for Commissioning. Column Commissioning. Column Startup and Shutdown. Operation Difficulties. Column Field Testing: Flooding, Foaming, Efficiency, and Troubleshooting. Troubleshooting Reboilers. Condensers, and Reflux Drums. Column Control Philosophy. Reboiler, Condenser, and Pressure Controls. Composition Controls. Miscellaneous Controls. Columns That Did Not Work: Case Histories. Appendices: A: Useful Conversions. B: Revised Equations for Constructing Startup Stability Diagrams.