CDU/VDU will process crude from storage and will provide feeds to the following units, accordingly to the block flow scheme:
- Full range naphtha as feed to the NHT
- Kerosene as feed to DHT
- Light atmospheric gas oil as feed to DHT
- Heavy atmospheric gas oil as feed to DHT
- Light vacuum gas oil as feed to DHT or as fuel oil cutter
- Medium vacuum gas oil as fuel oil cutter
- Heavy vacuum gas oil fuel oil cutter
- Vacuum residue as feed to VIS
- Vacuum residue as feed to bitumen production
- Vacuum residue as fuel oil
Crude from storage will be preheated in 4 stages and (including heat exchanger, de-salters and pre-flash drum) will pass through a fired heater to gain necessary heat for product separation in the atmospheric column. The primary objective of the ADU is to separate the crude boiling range cuts to meet the desired product specification.
The full range of naphtha will be sent to NHT, the kerosene and atmospheric gas oil will be combined to feed the DHT, and the long residue will be fed to the VDU.
The aim of the VDU section is to fractionate the atmospheric residue under vacuum condition to produce vacuum gasoil and VR that will be processed in the downstream units. The column separates the long residual into light, medium and heavy vacuum gas oil and VR.
The light vacuum gas oil will be fed to the DHT; VGO will be fed to storage to use as fuel oil. VR will be fed to the BBU for the production of paving bitumen. However, a portion of VR will be fed to VIS. The BBU has been included in the refinery configuration since bitumen production for road construction. In addition, producing bitumen is more desirable if a permanent shutdown of the Homs refinery, currently the major bitumen supply source for this area of the country, is expected to occur shortly after the startup of the refinery.