Energy Consumption in a Crude Oil Refinery Distillation Process

I bet james stewart could explain this.

That advice may be found in the design documentation and the commissioning records for the plant. No-one else here can see it.

Is this for a term paper?

Thesis?

Have you asked the API?

Your best source for an answer would be from an operating refinery.

Good luck with that these post 911 days. I got run down, cornered, and then run off from the public road beside a refinery last month for taking pictures, per instructions from NSA. I doubt any are going to discuss operations anymore.

http://www.ilo.org/iloenc/part-xii/oil-and-natural-gas/item/384-petroleum-refining-process

Sorry, I should have concentrated on steam, not heat.

The answer remains roughly the same. Any plant generating it's own steam, will use that steam for heat-tracing it's piping and vessels. There is also a requirement for super-heated steam.

Generally heat losses would arise from: Geometry of the plant (piping especially, owing to length of pipe runs; plant and vessel size; integrity of insulation; efficiency of steam turbines; boiler capacity/ throughput etc ....

Steam losses occur due to integrity of vessels and piping, valve packing, turbine efficiency etc etc...once you have a home grown supply, in-house engineers find it more and more attractive to power up modifications to plant and to power additional plant equipment. There are losses to both heat and steam during routine maintenance outages, and also breakdown in the steam supply equipment eg pressure let-down stations, pressure and temerature control valves, steam-cuts on fittings, failed gaskets etc...etc..ad nauseum.

Naturally, the boilers (aka 'steam generators') must be shut down for periodic inspection and maintenance (refer to ASME/ similar) and those losses (I call them losses, but other might not) must also be reckoned in....list just goes on and on..and that's why it becomes very difficult to predict. Of course , one can do estimates/worst case/ best case, but aside from an academic practice, there is no real value in those results.

OK i'm done now...feel a lot better for the mini-rant, thanks!

You really can't isolate steam from all the other energy intensive streams that go into a modern refinery. Every chemical engineer has to take a series of courses known as "Unit Operations"where every factor of process design is discussed, so the data is hardly a secret.

What is proprietary are the trade secrets that make one refinery more efficient than another; however mass, steam, energy, and material balances tend to contain the information you're looking for. As others have said, there is no universal guideline since each plant is different, and even in the same plant the differences in the raw feedstock require fine tuning of the processes so what's true today will be different tomorrow.

I agree, (as per my first response).

However, from the OP's post not directly addressed "Where is the steam used in the greatest quantities and does anyone know of methods or resources to determine analytically the amount of steam that needs to be produced?"

Calculating the amount of steam required, means having to know exactly what the total heat tranfser rate to the feedstock is, continuously and with certainty.

Nothing is impossible I guess (and I have worked with pretty smart Chem engineers in my time), but accurate calcs under the specified conditions were always above my pay grade in any case. I have no doubt that there exists a software simulation somewhere,that can do this, version number $$$$$!!!. Next best option is to call around the universities...maybe someone has done and published such a study.

Yes, there are simulators out there, as well as academic papers, these are the ones at the top of a Google search.

"...one can do estimates/worst case/ best case, but aside from an academic practice, there is no real value in those results..." I disagree, the real value is that they set the Bogey (target range) for the plant. Plant management is held accountable for any variations outside of these ranges. Without them how would you even know whether you are operating the plant properly and/or how efficient your operation is?

Ram,

You have provided good, considered responses, thanks. I have not ever had the joy of software package calcs on a new plant..what you read of mine previously are the opinions of the grunt tasked to do manual calcs on old (ish) plant with plenty of steam already escaping.

Hilton, Neither have I, but I do remember walking around a 660MW supercritical boiler when the windchill was -20ºF and feeling warm 5 ft from the walls. When I asked the chief engineer how much heat was being blown away he said, "...it's built into the design specifications..."

When you're burning 320+/- tons of coal per hour, a few pounds here and there are just part of the overall losses in power production. I did notice that the more modern plants had thicker insulation and tighter cladding as the escalating price of fuel started figuring into the calculations.

"...it's built into the design specifications..."

Yes...heard that one many times (in respect of other things as well), but never seen it in writing..

In spite of Kulas "belief" in me, I must preface my post by stating I have absolutely no idea of the actual steam or heat requirements for any refinery in operation.

What I can say is that the burn off is in the furnace that pre-heats the oil upstream of the distillation unit.

The utilization of steam varies also, but I suspect that much steam is required for any plant that has to heavy hydrotreat to upgrade stocks from naphthenic to more of a paraffinic character, or adjust ratios between paraffinics and aromatics. Steam is also injected into the distillation unit side-strippers, but this steam is usually of a lower BTU value (temperature, pressure), and as such might not constitute the majority of steam demand. Some steam is usually available to drive rotating equipment as pumps, generators, gas compressors, etc., although in recent years the trend is to utilize gas turbine equipment to handle the job of prime mover.

Bottom line: As others have stated, this is a case-by-case basis, and deals with very sensitive proprietary information each company will guard closely.