Designing CDU Preheating Train Thermally Coupled to DCU through Vacuum Residue Temperature

Developed by: AIChE
  • Type:
    Conference Presentation
  • Conference Type:
    AIChE Spring Meeting and Global Congress on Process Safety
  • Presentation Date:
    March 22, 2010
  • Skill Level:
  • PDHs:

Share This Post:

Crude oil distillation unit (CDU) and Delayed coking unit (DCU) present significant energy consumption in a refinery, given the high flow rates involved on process streams. As refiners are increasing the process of opportunity crudes, heat integration on these units becomes more relevant. Because DCU is essentially a semi-continuous process, heat integration involving its hot streams may impact considerably the CDU operation. However, thermal coupling between CDU and DCU can be explored through the evaluation of adequate DCU feed temperature. By increasing vacuum residue temperature to DCU, the DCU cooling demand increases while CDU cooling demand decreases. As pinch location on each unit is relatively high, little influence on heating demand is expected, unless the pinch is modified by variation on vacuum residue temperature to DCU. Capital costs are supposed to suffer variations as well, especially on DCU, due to the required area to preheat the feed and to cool the product streams. This work presents the evaluation of DCU feed temperature relevance on both CDU and DCU overall costs and utility consumption, considering grassroots designs, based on Pinch Analysis approach. Steam generation on each unit will be investigated for an interval of vacuum residue temperature, in order to evaluate the replacement of cooling water expenditure by steam generation revenue. The paper will also discuss the impact of increasing thermal coupling between units in terms of flexibility. Design considerations due to eventual operation, such as vacuum unit shutdown, will be addressed as well.

This recording is FREE to members of the Fuels and Petrochemicals Division of AIChE. AIChE members may join the Division for only $10. Join F&PD now and return to this page with your new log-in and you will receive this presentation for FREE.
F&PD Members: Simply click on “click here to buy this archived webcast ” below and your ‘0’ price will appear in your shopping cart.
Once the content has been viewed and you have attested to it, you will be able to download and print a certificate for PDH credits. If you have already viewed this content, please click here to login.



Do you already own this?

Log In for instructions on accessing this content.


AIChE Member Credits 0.5
AIChE Members $15.00
AIChE Fuels and Petrochemicals Division Members Free
AIChE Undergraduate Student Members Free
AIChE Graduate Student Members Free
Non-Members $25.00