Report on a Visit to the CDU Unit at the Duqm Refinery With a view to better understanding and linking external absorption to practical application, a field visit was conducted to the atmospheric distillation unit (CDU) in Duqm.Deaerator (Dissolved Gas Separator) We learned about the operation of a carbon deaerator, which removes dissolved gases such as oxygen and carbon dioxide from boiler feed water to prevent corrosion in boiler equipment.Heat Exchanger We observed the thermal heat exchangers used to transfer heat between different fluids, whether to move crude oil before it enters the furnace or to recover heat from external products.Compressor We also expected controls for compressing gases generated or used in central processing unit operations.We observed how this dynamic tool improves energy efficiency within the unit and reduces fuel consumption.The engineers explained how the device works and the importance of maintaining specific levels and pressures for optimal performance.2.3.4.?