Transport of Ethanol by Pipeline 1

[EmeryRJ]

Is there any reason why ethanol in bulk cannot be transported by a mixed commodity pipeline (i.e., one that also ships gasoline, diesel, jet fuel, etc.)?

 

[JLSeagull]

The pipeline should verify that elastomers are compatible for many components at the terminals. I gather that the question pertains to fuel grade ethanol. API published a few studies such as ethanol storage integrity and TR 939 D on stress corrosion cracking of carbon steel in ethanol. Search the API publications for help.

 

[owg]

Ethanol will pick up all the water and some of the dirt adhering to the walls of the line and may need some reprocessing depending on the end use.

HAZOP at

http://www.curryhydrocarbons.ca

 

[EmeryRJ]

But shipping ethanol itself, whether it picks up water or not, is and of itself not dangerous or any more explosive than shipping gasoline, diesel, kerosene or jet fuel in the same pipeline?

How are the different commodities separated in a pipeline?

How much intermixing occurs?

How are such fluids pushed or pumped through the pipeline?

 

[JLSeagull]

The explosion proof requirements for electrical components are not much different as ethanol is a group D component.

Product pipelines batch the assorted refined products in a sequence to minimize incompatible interfaces. Some mixing occurs at the interface. I don't know the quantitative or qualitative measurements. I suspect that the mix zone is less than 100 barrels. The pipeline volumetric flow rate predicts the interfaces and changes in properties such as density identify the interfaces. The switching also follows a sequence. For example assume that diesel is badly contaminated by gasoline but gasoline can tolerate some diesel. Switch into the diesel tank after all gasoline is gone and switch out of the diesel tank at first indication of gasoline. A similar rule would exist between diesel and jet fuel if diesel could tolerate some kerosine and jet fuel would be contaminated by diesel. There could be similar rules if the same pipeline carried ultra low sulfur diesel and offroad diesel.

Fluids are pumped through the pipeline; unless looking at the downward direction from a mountain where a surge station slows the flow to maintain the liquid pack. Backpressure is maintained to keep LPG products in liquid phase. Flow meters are the cash register. Pump starting may be sequenced to avoid electrical consumption pricing spikes.

You can bet that there are lots of rules, regulations, codes, standards etc. in addition to company practices to maintain these quality issues.

 

[0707]

In my opinion the reason why ethanol is not transported through pipelines is because this industry is no “enough mature” to develop its own distribution facilities, for that reason this industry has to use traditional transportation such as car trucks, train trucks or vessel transportation. The problems related with water are the same for traditional gasoline or for ethanol.

Ethanol is more mixable with water than gasoline. Pipelines for ethanol transportation should have at the end of the distribution pipeline a kind of molecular sieve devices to remove any traces of water. Water contamination is also possible in actual traditional ethanol transportation, and cannot be used as an argument to impeach the use of pipelines in ethanol transportation

 

[JLSeagull]

Assume that this post applies to 85% or higher ethanol. So, how about the gasoline that contains 10% ethanol? Does water azeotrope in that ethanol too? Ethanol is widely used today as an oxygenate in a 10% mix with gasoline. The problems encountered with "gasohol" include elastomer swelling. According to the API study "Executive Summary
Literature Review, Impact of Gasoline Blended with Ethanol on the Long-Term Structural Integrity of Liquid Petroleum Storage Systems and Components" an alcohol water phase separates when water exceeds 0.5%. This water mix is about 75% ethanol, cosolvents and 25% water.

Again API has it covered. Read the reports.

 

[EmeryRJ]

JLSeagull,

Please define for this neophyte what is an elastomer and elastomer swelling in the context used in this thread.

 

[dcasto]

elastomers are the flexible sealing pices used in valves, pumps, and other componets. They are made of rubber, viton, butyl rubber, teflon, and all sorts of other compounds. They will flex and seal the material being handle by the aformentioned parts. O-rings are typical items made from elastomers .

elastomers are porous, some more so than others (you can imagine the pores can help make them flexible. certain molecules can enter the pores and "fill" them up and cause the whole elastomer to grow. In extreme cases, the fluid will enter the elastomer and the resulting swelling will cause the elastomer to fail and a leak results.

It is really fun to pull a butyl rubber elastomer that has been in contact with ethane, ethylene, ethanol out of service. The 3" oring will swell to about 4" and be twice as big around after a few minutes. Then blisters will form and the ring will pop as the gases expand inside the elastomer (due to lower pressure)

 

[dcasto]

Look up what makes an E85 vehicle different than a normal vehicle. All the elastomers were replaced and the fuel system is almost all stainless steel.

 

[0707]

JLSeagull

The problem related with ethanol transportation in pipelines is not water. The problem related with ethanol transportation seems to be corrosion; API defends to have experience Stress Corrosion Cracking in some ethanol pipelines. This Stress Corrosion Cracking has also occurred in traditional oil gasoline transportation. And cannot seriously be used as an alarmism against dedicated ethanol pipelines.

Ethanol pipeline is an economic question

When Ethanol production facilities became relatively big and spread out, and have enough network aggregate, ethanol pipeline transportation will grow up.

 

[JLSeagull]

As previously stated, API TR 939 D is a publication about stress corrosion cracking of carbon steel in ethanol. Ethanol is not a new product. Within petrochemical facilities ethanol is handled in carbon steel piping and tanks. Agricultural based ethanol is new and may require changes in pipeline distribution practices; or a completely separate transportation system. Bio-diesel is another renewable energy source that will increase in the market. Things change.

 

[EmeryRJ]

JLS,

Ethanol is ethanol. How is ethanol derived from petrochemical sources different from ethanol derived from agricultural sources?

Also, can anyone point me to an unbiased article that discusses the pros and cons of shipping ethanol via pipeline?

Next, how is ethanol today collected and consolidated for bulk shipment (by rail?) across the country?

Finally, if ethanol causes steel to corrode, are all the railroad tank cars being used to ship ethanol lined with glass or stainless steel?

 

[EmeryRJ]

dcasto,

Look up what makes an E85 vehicle different than a normal vehicle. All the elastomers were replaced and the fuel system is almost all stainless steel.

To my knowledge, all vehicles manufactured and operated within Brazil can operate on 100% ethanol or 100% gasoline or any mix in between. Every gas station has pumps that a motorist can set to the desired mix before filling their tank. I rather doubt all those vehicles have costly stainless steel fuel systems.

 

[pipehead]

Besides corrosion, think vapor pressure too (Vapor locking and pressurized fuel tanks). ethanol is very hydroscopic (remember your last hang over?)

 

[EmeryRJ]

pipehead,

I think you meant hygroscopic. Regardless, how does that affect pipeline transport of ethanol? And where does the water come from?

 

[JLSeagull]

Lots of ethanol is stored in atmospheric storage tanks without a nitrogen purge. In these cases ethanol absorbs water from the air.

Another thread from Brazil suggests that ethanol is not presently transported via pipeline but they were studying or planning for such.

 

[pipehead]

Ethanol will even pull the water out the gasoline it is mixed with because of polarity of the two. The ethanol and water will settle to the low points in a pipeline and start corroding the line.

Since most pipeline are batched, ethanol is a contaminate to some products at the ppm level, where the gasoline that contaminates the next product could be in the 1% range. So batch lines don't want the ethanol in their system.

If you were to make ethanol and dry it with mole sieves, then a dedicated ethanol line would be ok.

Presently we have trucks come in with 10% ethanol in the truck and we top the trucks off with natural gasoline and the truck mixes the stuff on it way to a filling station.

 

[BigInch]

See this thread!

thread481-165850

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com