6 replies to this topic

[joeblack]

Hi everyone
I'm just new here and was wondering if this forum can be useful for me too.
I'm doing a research on crude distillation plans and as you know and according what is written in wikipedia, there are hundreds of different oil refinery configurations. can you give me a hint or any reference to look for more common refinery plans? I don't need them in details, only schematic depics suffice.
thanks in advance

[Zauberberg]

http://www.cheresour...om/refining.pdf
http://www.osha.gov/...v/otm_iv_2.html

[StealthProg]

It depends on what the purpose of your study is, refinery configurations vary depending on the feed crude types, the desired end products and occasionally the product specs in a particular location amongst other things. For example in Europe, with Gasoline in surplus and Diesel in shortage, new refineries would tend to look at Hydro cracking rather then FCC configurations and that would impact the choice of the remaining units also.

[joeblack]

It depends on what the purpose of your study is, refinery configurations vary depending on the feed crude types, the desired end products and occasionally the product specs in a particular location amongst other things. For example in Europe, with Gasoline in surplus and Diesel in shortage, new refineries would tend to look at Hydro cracking rather then FCC configurations and that would impact the choice of the remaining units also.

Thank you Zauberberg for your good links, but they give informations on one typical refinery (and of course most common one) but I'm looking for several refineries to make a comparison between methods which are used these days. Mostly on feed preparation and CDU/VDU units. Do all refineries have this typical sequence?: HE preheat, desalting, HEs, (one) pre-flash, HEs, fired heater, CDU/VDU and so forth.

StealthProg,
yes I know the configuration changes with crude oil properties, most desirable products, optimization objectives.... I was told to find out how feed preparation and fractionation changes with situations. The downstream units (NHT,GHT, CCR, FCC are less important)

I got 3 different crude distillation methods (3 different licensors) in "Hydrocarbon Processing's Refining Processes 2006 Handbook" but these do not satisfy me.

Edited by joeblack, 05 January 2010 - 07:04 AM.

[Zauberberg]

Thank you Zauberberg for your good links, but they give informations on one typical refinery (and of course most common one) but I'm looking for several refineries to make a comparison between methods which are used these days. Mostly on feed preparation and CDU/VDU units. Do all refineries have this typical sequence?: HE preheat, desalting, HEs, (one) pre-flash, HEs, fired heater, CDU/VDU and so forth.

Pre-flash is an optional design approach, and sometimes used for debottlenecking existing crude units. It is a part of original design in some instances, e.g. for handling very light crude oils. There are options for using preflash drums and preflash fractionation columns.

Essentialy, the answer on your question is - yes. That's the only order of process units: CDU/VDU --> units downstream (NHT, CCR, HDS, FCC, HCR, VBR etc.). The configuration of CDU/VDU may vary up to certain extent (e.g. number of pumparounds, side-product draws, naphtha draw point...) but these are dependent on crude type, site conditions, perhaps local market conditions etc.

[StealthProg]

It depends on what the purpose of your study is, refinery configurations vary depending on the feed crude types, the desired end products and occasionally the product specs in a particular location amongst other things. For example in Europe, with Gasoline in surplus and Diesel in shortage, new refineries would tend to look at Hydro cracking rather then FCC configurations and that would impact the choice of the remaining units also.

Thank you Zauberberg for your good links, but they give informations on one typical refinery (and of course most common one) but I'm looking for several refineries to make a comparison between methods which are used these days. Mostly on feed preparation and CDU/VDU units. Do all refineries have this typical sequence?: HE preheat, desalting, HEs, (one) pre-flash, HEs, fired heater, CDU/VDU and so forth.

StealthProg,
yes I know the configuration changes with crude oil properties, most desirable products, optimization objectives.... I was told to find out how feed preparation and fractionation changes with situations. The downstream units (NHT,GHT, CCR, FCC are less important)

I got 3 different crude distillation methods (3 different licensors) in "Hydrocarbon Processing's Refining Processes 2006 Handbook" but these do not satisfy me.

Most of the stuff in the books is out of date and inefficient, especially from a heat integration point of view. Speaking from a European point of view the majority of crude units were built in the 1960's and I suspect the same may apply in the states. Many have been revamped since then to increase capacity and some new units will have probably been built, especially in other parts of the world. The results is you will see every possible combination of things that can be done and most of which should never have been. One example is the flash vacuum column which was designed using faulty design methods and which are a historical curiosity for the most part. Ditto dry vacuum columns.

A refinery may have;

CDU
CDU/VDU
VDU
CDU/MVDU/VDU

CDU themselves may have a flash tower (reboiled or otherwise), flash drum, or neither.
CDU desalting may be one stage or two stage.
VDU may be low vacuum to deep vacuum or anything in-between, dry, semi-dry or wet.
CDU residue may go directly to the VDU heater or it may go via exchangers

Product Stripping can and has been done by steam, nitrogen, vacuum or reboiling to varying levels of success.

A 'typical' CDU/VDU would look like the following, HE's, Desalters, HE, Preflash, HE, furnace, CDU, Furnace, VDU. Very few of the older CDU's are well designed. If you look at existing refineries, by and large you will be looking at something designed 50 years ago and revamped since by Johnny GiveMeBucks. Deep cut vacuum columns are more recent (than 50yrs) and are also often poorly designed and have problems with coking in the wash sections as a result, usually when they are poorly designed its often to do with Johnny GiveMeBucks contractor giving the simulation work to some grunt just out of university. You'd be surprised how often engineers think a deeper vacuum means less heating requirements. (ok rant over).

The simplest configuration i've seen recently was crude fed straight into the VDU furnace and into a mild vac column (but thats a special case)

[joeblack]

It depends on what the purpose of your study is, refinery configurations vary depending on the feed crude types, the desired end products and occasionally the product specs in a particular location amongst other things. For example in Europe, with Gasoline in surplus and Diesel in shortage, new refineries would tend to look at Hydro cracking rather then FCC configurations and that would impact the choice of the remaining units also.

Thank you Zauberberg for your good links, but they give informations on one typical refinery (and of course most common one) but I'm looking for several refineries to make a comparison between methods which are used these days. Mostly on feed preparation and CDU/VDU units. Do all refineries have this typical sequence?: HE preheat, desalting, HEs, (one) pre-flash, HEs, fired heater, CDU/VDU and so forth.

StealthProg,
yes I know the configuration changes with crude oil properties, most desirable products, optimization objectives.... I was told to find out how feed preparation and fractionation changes with situations. The downstream units (NHT,GHT, CCR, FCC are less important)

I got 3 different crude distillation methods (3 different licensors) in "Hydrocarbon Processing's Refining Processes 2006 Handbook" but these do not satisfy me.

Most of the stuff in the books is out of date and inefficient, especially from a heat integration point of view. Speaking from a European point of view the majority of crude units were built in the 1960's and I suspect the same may apply in the states. Many have been revamped since then to increase capacity and some new units will have probably been built, especially in other parts of the world. The results is you will see every possible combination of things that can be done and most of which should never have been. One example is the flash vacuum column which was designed using faulty design methods and which are a historical curiosity for the most part. Ditto dry vacuum columns.

A refinery may have;

CDU
CDU/VDU
VDU
CDU/MVDU/VDU

CDU themselves may have a flash tower (reboiled or otherwise), flash drum, or neither.
CDU desalting may be one stage or two stage.
VDU may be low vacuum to deep vacuum or anything in-between, dry, semi-dry or wet.
CDU residue may go directly to the VDU heater or it may go via exchangers

Product Stripping can and has been done by steam, nitrogen, vacuum or reboiling to varying levels of success.

A 'typical' CDU/VDU would look like the following, HE's, Desalters, HE, Preflash, HE, furnace, CDU, Furnace, VDU. Very few of the older CDU's are well designed. If you look at existing refineries, by and large you will be looking at something designed 50 years ago and revamped since by Johnny GiveMeBucks. Deep cut vacuum columns are more recent (than 50yrs) and are also often poorly designed and have problems with coking in the wash sections as a result, usually when they are poorly designed its often to do with Johnny GiveMeBucks contractor giving the simulation work to some grunt just out of university. You'd be surprised how often engineers think a deeper vacuum means less heating requirements. (ok rant over).

The simplest configuration i've seen recently was crude fed straight into the VDU furnace and into a mild vac column (but thats a special case)

Thank you both, specially you StealthProg that was a thorough great answer to my questions. Flash vacuum column was one of questions which you answered before I ask. I really appreciate it.