Pickup Trucks and Oil Refinery Discussion - A Jay and Jimmie Production

Well, that is a good way of describing it. I would suggest the middle trays output of the CDU require the least processing

 

Don't forget the use of very expensive rare-earth catalysts, which must be replaced on a regular basis. Still, it's better than just dumping or flaring off "undesirable" byproducts

Too bad the same thing can't be done to shale processing. A lot of the wash water is a soupy muck that has high levels of heavy metals, currently they sit in giant settling ponds.

That's something the shale proponents never tell you

 

A lot of folks are unaware of the requirement for settling ponds to handle the contaminated water from shale processing. It's a simple fact that after "washing" the shale you have enormous amounts of arsenic and cadmium.

The reason the shaleoil must be "washed" is to get that crap out. Otherwise you'd kill the catalysts used in the refinery

So what you have left over is a concentrate toxic sludge with no real plan to deal with. I suppose they figure if they wait long enough, the earth will crash into the sun and take care of the problem

Seriously, there are means to take care of the toxic sludge, but the treatment cost is so bloody high that if factored into a barrel of syncrude, tack on another $15

Anyhoo, leaving tomorrow on another business trip, should be back Friday. Will try to have the diagrams numbered so the process is easier to follow

 

I've added a second general process diagram to my posts. The generic process diagram will have a red box superimposed on what part of the process I'm secribing

 

Crude Part IV: Catalytic Reforming

I would like to describe what happens in the last stage after isomerization, which is Catalytic Reforming. In catalytic reforming, the aromatics from the isomerization process are converted to gasoline blends and hydrogen gas

The actual catalytic process is typically a 3-step process using 3 reactors. The first step is the naphtha’s are heated to about 900 F and pressurized up to 45 atm, then sent into the first reactor. The gases react with the catalyst which causes the naphthenes to dehydrogenate, creating aromatics. As an example, methylcyclohexane to toluene and hydrogen gas. This is endothermic, so the gases must be preheated before the second reactor

In the second reactor, the aromatic paraffin’s are isomerized to isoparaffins. For example, n-octane to 2,5 dimethylhexane. You can also expect the paraffin’s to dehydrogenate and to undergo aromatization, such as n-heptane to toluene and hydrogen gas.

The resulting gases must again be heated up. In the third reactor, the remaining n-heptane is mixed with recycle and generated hydrogen to produce isopentane and ethane. The resulting mixture is sent through a chiller and a gas separator, which collects the excess hydrogen.

The resulting liquid from the chiller and gas separator is sent through a fractionating tower, and I’m sure you’ve noticed there are quite a few fractionating towers in use within a typical refinery. In this fractionating tower, the liquid is heated up again.

The lightest aromatics from this fractionating tower are typically methane, propane, ethane, butane, and trace hydrogen. These gases are collected at the gas processing plant within the refinery, the propane and butane are useful products. The remaining gases are used as fuel to run the plant. The bottom liquid from the fractionating tower, called a “reformate,†are used as gasoline blend.

Most often, the catalyst used is platinum, rhenium, a combination, and/or proprietary elements. The catalyst must be regenerated – usually on site - every 4-8 months of continuous operation, more often if the crude feedstock is heavy with sulfur.

This now concludes my brief discussion of the typical oil refinery process. If anybody would like me to expound on any part of the process, or certainly the waste handling aspect, please let me know. Likewise, if anybody would like me to discuss extraction techniques, please let me know

I’m leaving tomorrow for another week or so, hopefully back next Tuesday. I’m sure at least some of you will have questions or comments

 

Hello John

There isn't much excess hydrogen from a typical refinery process. Most of the hydrogen is needed in steps involving catalytic reactions, which I briefly touched on in other posts

What little excess hydrogen left over, can be cleaned and sent offsite for lab use. There is no way you could expect enough hydrogen to power cars, it would be far more efficient to simply power the engine with regular unleaded

Flaring is still done to gases that cannot be used in the process and have little to no commercial use. A lot of the sour gas from fractionating towers used to be flared off. In the past 20 years a lot of research has resulted in the capture of these former waste gases

Primarily, the waste gases can be used as part of a co-generation process to generate electricity in the refinery. The excess power can be put into the grid.

In the event of a process upset - which is fairly common with older plants and old control systems - you will generate enormous volumes of naphthas, hydrogen, butanes, and other explosive gases. Without a quick way to deal with that, you could have a catastrophic explosion

Parts of the process most likely to experience sudden pressure upsets are connected to a flare gas header system. When pressure exceeds a setpoint, the excess is sent to the header pipe system

There is always a small flame at the tip of the flare pipe, think of it like a pilot on a gas water heater or stove. There are also damper systems and steam injection nozzles at the flare tip.

When there is a process upset, the excess gas is sent to the flare pipe header system, then into the flare column itself. The small flame at the top will ignite the excess gas, automatic dampers are supposed to control the flame (Not too rich or a lot of black smoke will result), and the steam injection minimizes visible and particulate emissions.

There is a lag time for everything to respond. The sudden burp of gas tends to create a huge orange/black fireball out the tip, then as the steam nozzles and dampers respond, it becomes a bluish/white flame until it dies down as pressure bleeds

International law calls for minimising and even forbidding routine flaring. Not sure if folks are aware of this, but globally about half the natural gas needed to run the US is flared off oil wells each and every year. This is primarily in African, South American, and Russian oil fields.

It's a very wasteful practise

 

Try heavy drinking. That seems to work for me!

 

That's why I've always gotten quite hot under the collar when a doo-fus brought it up.

I'd suggest that back in the "good 'ole days" of Sudbury, it was as bad as tar sands is right now. It took INCO a long time to clean things up, using technology they had access to +40 years ago.

Currently, with the effluent sludge rich in toxic heavy metals, nobody really has a clue what to do about it. Thus the giant man made lakes chock full of the stuff. And the occasional "whoopsy-daisy" moment

Syncrude Canada Ltd. - News Room

He never admits to being wrong. He'll make up new numbers, change the outcome, but of course, he is NEVER wrong

A pure EV would rely on far less of it. Modern petrochemical processing has massive and continuous demand for rare earth catalysts, compared to the one-time demand for a rare earth magnet material

 

Re: I have betrayed you all.....sorta

Of course, even a short 20 years ago, folks in the engineering community already had fear of WAG's (Wild Assed Guess) of oil needing to be +$100 a barrel to ever think of uncapping some wells, or considering goey tar-like stuff in Wyoming, Utah, ND, and Alberta.

IOW, we'd have to already be in very deep s***. Guess what? Looks like we're at +$100 a barrel. So we're now in very deep s***. As in FUBAR

No no, patience has nothing to do with it. I credit Kokanee beer and Bombay Sapphire Gin, not necessarily in that order or even mutally exclusive. The sudden upswing in petrochemical consulting is a direct consequence of scarce resources

Now that I think about it, a lot of the more depressed engineers and policy planers I know appear to be stocking up on hard liquor, rather than food supplies. They also appear to be almost constantly s***faced. I guess whatever helps you cope with bad news that cannot be fixed

Not to mention the booze has a much longer shelf life than boring, ordinary food

 

Well, that would depend on how the particular refinery is constructed. Eg: the naphtha hydrotreater, the isomerization unit, and the catalytic reforming unit. Each step can introduce bottlenecks and obvious upsets

For the most part, you can expect to change the yield of propane vs benzene most economically by changing process setpoints in the frac tower. Minor changes in the iso unit and the cat reform unit can also influence gas output

For the most part, unless there is a wild change in demand for one gas or another, there is a fair amount of flexibility in process gas output. Keep in mind that the design of the various catalyst units is about as optimized as can be made.

Unless we have a dramatic breakthrough, don't expect any sudden efficiency gains

 

Re: I have betrayed you all.....sorta

Oops a rushed sentence on my part. Nope, I've also never thought of using beer as a mixer for gin. I usually drink them separate. For some reason, I prefer cranberry juice as a mixer for gin, gives it more of a Pucker Factor

Anyhoo, leaving this afternoon on a business trip. Should be back Saturday