CPI vs API Oil Separator

I want to know the advantage and disadvantage of CPI and API for removal of oil.

Taxonomy

• Oil & Gas
• Oil Water Separation
• Oil Field Chemicals
• Oil Spill Treatments
• Heavy Oil

6 Answers

1. Pak Water Expo in Pakistan

2. if you chose the right material for the tilted plates, the CPI can function also as a coalescer

3. Dear Mahmud,

   both API and CPI are based on the same principle of the gravity separation based on the difference of density between oil and water. Hence the field of applicability is the same.

   Actually the design of each of them is guided by the same code API 421 and I recommend you to study it and  find many answers there.

   API is normally used for the primary treatment of high oil concentration and reduce it before other separation treatment steps. 

   CPI is normally preferred when the inlet oil concentration is below 1000 ppm and can be reduced eventually to less than 50 ppm (efficiency 95% typically higher than API).

   API is a large basin which requires large land whilst CPI is a more compact package unit which can be fabricated at shop and easily installed at site, ready to work. Hence CPI is preferred in the  majority of cases.

   2 Comments

   1. Yes this is correct and I agree with Marco and Rafael's minor correction, albeit important...

   2. Just a clarification, while API is based on experimental work for droplets of 150 micron dia. and Stoke's law, CPI is based mostly on a theoretical approach to plates on basis of the Stoke's law. For the rest I fully agree with Marco. 

4. Both technologies are in use. For Crude separation (sp. HO crude extraction) designers tend to go API. For light Oils CPI could be more efficient (and less costly).

5. Mahmud, in general these approaches are very similar and as Sean explained below the subtle technological advances associated with the CPI approach provide marginally better results/economics although do have drawbacks around reliability.  Our approach at Clean Industrial has been deploying rapid oil water separation capabilities in mobile platform - using an integrated membrane system (IMS).  This system is comprised of an upfront liquid-liquid centrifuge and a ceramic membrane system that are controlled by an intelligent control system which enables a high level of efficiency / reliability of the robust UF ceramic membrane system.  This approach allows for instant separation and often is able to break emulsions that would otherwise remain in a gravity based system.  Our IMS approach gives you high quality effluent / filtrate, ability to deal with varying influent qualilties, rapid and reliable separation via a very small footprint.

   1 Comment

   1. Can you provide a comparison between the CAPEX and OPEX vs Conventional.  I mean you do have a lot of energy needed to run a centrifuge and then there is always potential membrane fouling.  I am assuming this is for an oil refinery.  This may help in the decision-making process. Just my thoughts as I was reading through your spec sheet. Don’t get me wrong I love the technology, but sometimes the economics are not there to run such a system. Can you aluminate those doubts for him? Thanks, Sean.

6. API’s require normally less manual cleaning, but work off high RT.  The CPI is historically more efficient reducing RT requirement substantially and usually providing higher quality effluent.  However, the plates need cleaned often to function efficiently.

   1 Comment

   1. RT - residence time?