2 replies to this topic

[olga]

For heavy crude oil processing :

What are the best options to design the fractionator? Is better to use dry column?.

These are my questions because some information related with the topic explain that wet column is better than dry column. I would like to know what the new tendencies are showing. Thanks for any help.

[Zauberberg]

Hello Olga,

It depends whether we are speaking about the existing Vacuum Distillation Unit (VDU), or is it a completely new design (grassroots project).
As you probably know, the intrinsic advantage of wet towers is they can use coil steam injection in order to suppress excessive feed cracking in vacuum furnace; in addition, use of stripping steam in the main VDU tower is also enabled for enhanced HVGO recovery. However, there are some dry unit designs (split-column system) in which stripping steam can also be applied for the purpose of Gas Oil recovery.

I believe you can see there are many key factors to be addressed before the final decision can be made: sometimes, it could be more cheaper to modify vacuum furnace and retain the existing dry tower system, instead of revamping the complete ejector system and (probably) column internals. You should conduct a full analysis of new crude (long residue) being processed through the VDU, and watch for different constraints as they appear throughout the study. There is no universal solution or "one size fits all" approach.

Here are some interesting technical articles which you may want to read. If you can provide additional data from your side, we would gladly do our best to assist you.

Vacuum unit revamps
Consider retrofits to handle high-viscosity crudes
Why vacuum unit fired heaters coke

Best regards,

[olga]

Thanks a lot for your information. I will read the technical articles.

Olga Martinez
Chemical engineer-Venezuela