Ethanol pumping 3

[vedranpetro]

Hi!
I have question regarding pumping of ethanol.It's new medium to me so my question would be do I need
some special consideration/equipment for pumping that medium regarding anti-explosion protection?
e.g. some anti-explosion valves on piping,drums with level indicators,...
Is there any possibility of explosion during pumping because of vapour pressure of ethanol in pipeline?
tnx in advance

 

[BigInch]

It is an inflammable substance, so where there is the possibility that oxygen, ethanol vapors and ignition sources are present, equipment should be rated for "explosion-proof" service.

Aside from that, ethanol has severe effects on some gasket materials, so be sure to warn your vendors that the equipment will be carrying ethanol.

It will not ignite inside the pipe, since presumably you do not have oxygen or an ignition source inside there. In and around tanks it could be possible.

You must do an "electrical" Area Classification Study before proceeding further.

What would you be doing, if you knew that you could not fail?

 

[vedranpetro]

tnx BigInch
one more question
is there any recommendation regarding choosing pump for ethanol- sealles vs. double seal?

 

[BigInch]

I would use a double seal API pump on any pump in inflammable service.

I found some notes I made on Ethanol pipeline transportation back in 2006. I have not built an ethanol pipeline yet.
===========================================
The biggest complaint by pipeline companies so far is about corrosion. It also seems that it is controversial. In any case, I believe it can be handled technologically, although it may involve substantial costs to old pipelines that want to convert using new gaskets and valve trims. That may be economically not feasible. Is it an excuse not to pump the stuff? Don't know. Maybe it just depends on if the pipeline wants to pump it or not. Most existing pipelines don't use aluminum or zinc inside pipes... maybe some zinc anodes in tanks? I haven't heard about that. They are used in water tanks, but not oil tanks as far as I know??? I don't think it would be any problem at all for a new pipeline.

************************************************************************

Buckeye Pipeline did tests in the 90s from New Haven to Springfield Ma
ethanol batches got cleaner with more being shipped
cleaned the pipeline of water deposits
should be shipped between reg nolead gasoline and premium nolead gasoline.
---------------------------------------------------
Amoco Tests
Higher concentration ethanol blends resisted separation for longer periods
Blends were more likely to separate with colder temperatures

****************************************************************************************
Potential problem areas,
**************************************************************************************

Corrosion (Apparently being used as a reason to squash pipeline shippment feasibility)
Water pickup from low areas in the pipeline
Sulfur pickup from pipeline wall deposits
Higher vapor pressure (gives a 1 psi lower NPSHA)
Discoloration
Making gums
Handling of interfacial mixtures generated with the leading and trailing products
Closed tanks needed to prevent rainwater leaking in from a floating roof.
Quality control programs
Safety procedures and training
--------------------------------------
"As is done in Brazil, neat ethanol shpment by commercial pipeline is seen to be viable in the Archer Daniels Midland-Williams Pipeline tests and observations."

(Don't know what this really means. Apparently there is a line in Brazil, but I can't find info on it yet)
----------------------------------------------
Petrobras is thinking about building a BIG one.

http://biopact.com/2006/04/brazil-planning-500-million-ethanol.html

http://www.greencarcongress.com/2006/02/petrobras_consi.html

-----------------------------------------------------------

http://www.us-dev.com/news.htm

Even though the sweet vodka-like smell of a tank car usually leaves little doubt it holds ethanol, Lomita's efficient six-person crew must sample the temperature, density, and clarity of each car before it's drained into a manifold running into a 4-mile ethanol pipeline. "This whole process is costly," says terminal manager Tim Lewallen, "but it's very little compared to contaminating a whole tank." There is always a remote chance a car could contain something else.

Next stop for ethanol from KAAPA and other Midwest producers is the Shell Oil Products U.S. 480-acre tank farm in Carson at the other end of the new pipeline. There, Shell has refurbished five 65,000-barrel storage tanks to hold ethanol. Those and other improvements made to switch from MTBE to ethanol cost the company $35 million. From there, 100 fuel trucks a day haul ethanol to blenders that supply gasoline to most of the major oil companies in the southern California market.

--------------------------------------------
SEMCO PIPELINE CO has recently filed for a permit to build an ethanol pipeline in Michigan.
----------------------------------------------

"Because ethanol can be corrosive to some metals and damaging to rubbers (gaskets and seals), fuel-storage tanks and dispensing equipment must be corrosion and damage resistant."
----------------------------------------------------------------------

http://age-web.age.uiuc.edu/faculty/qzhang/Publications/2005BT96(2)Hansen.pdf

"General corrosion was caused by ionic
impurities, mainly chloride ions and acetic acid. Dry
corrosion was attributed to the ethanol molecule and its
polarity. de la Harpe (1988) reviewed reports of dry
corrosion of metals by ethanol and found that magnesium,
lead and aluminum were susceptible to chemical
attack by dry ethanol.
Wet corrosion is caused by azeotropic water, which
oxidizes most metals (Brink et al., 1986). Freshly formulated
blends containing pH neutral dry ethanol
would be expected to have relatively little corrosive effect.
However, if a blend has been standing in a tank for
sufficient time to allow the ethanol to absorb moisture
from the atmosphere, it may tend to be more corrosive
as it passes through the fuel injection system (de la
Harpe, 1988). In addition, the fuel may stand in the fuel
injection pump for a number of months, for example in
a combine harvester engine, thus allowing the fuel time
to corrode parts of the pump internally. Corrosion
inhibitors have been incorporated in some additive
packages used with ethanol–diesel blends (de la Harpe,
1988).
Non-metallic components have also been affected by
ethanol with particular reference to elastomeric components
such as seals and O-rings in the fuel injection
system. These seals tend to swell and stiffen. Resinbonded
or resin-sealed components also are susceptible
to swelling and seals may be compromised (Bosch,
2001)."
--------------------------------------------------------------------------------

http://www.deq.state.or.us/wmc/pubs/factsheets/tank/FuelEthanolUSTSystems.pdf

Is Fuel Ethanol Compatible with Current Underground Storage Tank Systems?
In most cases the simple answer is probably not. Unlike petroleum-based fuels, ethanol conducts electricity. As such, it is much more aggressive in dissolving soft metals such as aluminum, brass, zinc and lead. Once dissolved, these metals may be deposited in engines following combustion and can lead to fouling and poor engine performance. Unplated steel, stainless steel, black iron and bronze have shown acceptable resistance to ethanol corrosion. Fuel ethanol may also cause rapid deterioration of some early generation (prior to 1992) plastics, fiberglass, cork gaskets, natural rubber and leather, among other materials. Some nonmetallic materials that have been successfully used with ethanol include thermoset reinforced fiberglass, Neoprene rubber, polypropylene, nitrile and Teflon, among others.
-------------------------------------------------------------------------------


Conventional Gasohol MTBE Reformulated
gasoline 10% Blend Gasoline

Vapor Pressure: Summer 8.7 9.7 8.7 7.2
Vapor Pressure: Winter 11.5 11.5 11.5 11.5
Benzene(vol%) 1.6 1.6 1.6 1.0
Sulfur (ppm) 338 305 313 302
MTBE(vol%)* - - 15 11
Ethanol(vol%)* - 10 7.7 5.7


What would you be doing, if you knew that you could not fail?

 

[vedranpetro]

tnx,useful tips

 

[stanier]

I guess the automotive engineers would have a hadnle on the corrosion aspects of ethanol and ethanol blends. Iunderstand that ethanol in some older vehicles corrodes the elastomeric seals.

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/

 

[BigInch]

I do believe that a car "should be rated for ethanol" use. Check your warranty before introducing ethanol into the tank.

What would you be doing, if you knew that you could not fail?

 

[vedranpetro]

stanier and BigInch
i'm talking about industrial pump ,and pure ethanol (cca 98%), not about cars and their pumps
and trying to figure out usual type of pumps for ethanol (sealles vs. mechanical seal)

 

[BigInch]

I know that.

What would you be doing, if you knew that you could not fail?

 

[JJPellin]

We have five pumps in our refinery that pump pure ethanol. All five of them are single-stage, overhung, API process pumps. All of them are made of cast carbon steel with 400 SS wear rings. All of them use spiral wound (flexitalic) gaskets. All of them use low temperature seals with Kalrez o-rings. Three of them use dual bellow seals and two of them use single, multi-stage pusher seals. We do not use Kalrez (very expensive) because it is the only alternative. We use it to allow for stocking consolidation. We use the same seal in other services. I would consider Viton acceptable (at low temperatures) or even EPR. I do not consider ethanol to be a particularly difficult service. I am not any more concerned about fire or explosion than I would be with LPG or other light hydrocarbon. For a new service that met the head and flow requirements, I would consider a canned motor pump just to eliminate the seal leak potential and save the cost of the API plan 53 system.

Johnny Pellin

 

[JJPellin]

Above post should say "multi-spring" pusher seal, not "multi-stage".

Johnny Pellin