Q1: Can ion exchange beds replace traditional water washing?
A: The best answer to this is that ion exchange beds are not a “one for one”
replacement for water washing of crude biodiesel. Water washing removes:
methanol, soaps, glycerides and other impurities -- all in one multi-staged process.

Ion exchange resins can remove very trace amounts of methanol however this is not
their primary function rather they are used to remove almost all other impurities.  In
this sense it can replace the water wash method but I like to refer to it as biodiesel
purification since that is exactly what it does - purify the alkyl-esters (biodiesel) of
soaps, positively charged ions (metals) and glycerin (glycerides).

Typical homebrew all though acceptable to your engine, most likely isn't meeting fuel
grade standards (ASTM). With ion exchange this is now an economically viable for a
small biodiesel producer.

To use this system you would follow the GL 1-day method using his EcoProcessor
with your Appleseed style reactor. This involves removing methanol via a venturi air
inlet. See the Biodiesel SVO Forums on the Internet.

Then spray biodiesel into a 55 gallon drum for 24-72 hours of settling (depending on
the amount of soap present - a 5% prewash with water at the end of your reaction
can reduce content).

At this point you will use our ion exchange column(s) by pumping off the top 50% (of
the drums biodiesel) at 8-10 gph (for a 6” diameter column) and passing the
biodiesel through the resin.

The biodiesel can then be used, however we suggest you run it through a simple
whole house water filter to ensure no foreign material gets into your fuel tank.

Q2: How many gallons and how long would the example of 20 lbs of resin
last?
A: If used as recommended - ~2000-6000 gallons of biodiesel purification depending
on the thoroughness of your process.

Q3: How much is shipping for your loaded resin to Naples, FL 34119?
A: Our 6” and 10" diameter towers have the shipping cost included in their price. For
our larger columns (12" dia. up) are shipped as freight and require individualized
shipping quotes to your specific location.

Please keep in mind, we work to deliver these palletized loads to business addresses
in order to keep shipping cost to a minimum.  Additionally if a lift gate is required for
unloading at a residential address then an ~$75 fee is charged by the shipper...

Q4: How much would shipping be for just 20 lbs of resin if it needs to be
replaced?
A: ~$25 (a good rule of thumb is ~$1 dollar per pound up to 200 lbs, after this
shipping cost go down due to bulk rates)

Q5: Can you throw away the resin?
A: Yes, the ion exchange resin is completely non-toxic and can be disposed of in any
land fill - provided the resin has been dried of methanol.

Q6: Should I remove excess methanol before or after using ion exchange
resin purification
A: Yes to both. The gel based resins like PD-206, BD10 Dry and Thermax's T-45 BD
Gel all require some methanol above 1% to work satisfactorily while Thermax's T-45
BD Macro resin has been successfully operated at levels down to <0.2%.  

In either case methanol helps the resin function however any methanol above 0.3%
comes at the price of dissolved impurities - the higher the level of methanol, the
higher the level of impurities needing removed by the ion exchange resin. Therefore
it is important to operate the columns at the minimum level of methanol possible.

We recommend gross methanol removal prior to the ion exchange resin with final
residual methanol removal post ion exchange...

Q7: I have a Northern Tool Pump, the same one many people use on the
forums, would this work for the unit? If not, please give me more
information on your pump.
A: The Northern Tool supply pump is a centrifugal pump and operates at perhaps 15
gallons per minute (gpm) with biodiesel.  For ion exchange resin column dry washing  
you need a positive displacement pump capable of flow rates ranging from 9 gallons
per hour (gph) for our 6" diameter column, to 300 gph for our 22" diameter columns.

Presently we use have 5 different style pumps depending on the Dry Wash Tower's
production capacity - the best of these, is are $750-$1,800  pumps and our designed
for the proper flow rates and highly adjustable. This ability to adjust the process flow
rate allows the user to accommodate for when the resin bed system begins to load
with impurities. The pumps flow rate can be adjusted very precisely in response to
ensure proper purification.

Q8: You mentioned that once you are done spraying the biodiesel into
the drum or tank for 24-72 hours, you would pump off the top 50%
through the resin. Why is this?
A: This ensures that the soap and glycerin which settle to the bottom our not
inadvertently sent to the resin columns. The bottom gallons act as a safety buffer but
the main idea is not to draw from the bottom region above the settled soap and
glycerin.

At some point when the settled soaps and glycerin exceed this buffer region, the
biodiesel producer will need to be remove this glop to avoid sending these gross
impurities directly to the ion exchange resin bed.

Q9: What do you do with remainder of biodiesel before you can run that
through as well?
A: You will always keep a small amount of biodiesel between your settled
soap/glycerin and the biodiesel you send on to be purified. This is your safety buffer
zone.

Q10: What is the expected cost of using resin for biodiesel purification?
A: The initial cost of our resin ranges from  ~$8 to $10 per lb. depending on the
amount purchased and if purchased with a column. When used as recommended,
each pound will purify ~100 gallons of biodiesel with total impurity concentrations
<1500 ppm.

Note: ppm is parts per million and refers to the weight of the impurities to the weight
of the biodiesel. For example the 1500 ppm mentioned above equates to 0.15% by
weight of a sample of biodiesel.

Parts per Million our based on the metric system at 1 mg/Kg.
Dry Washing Biodiesel Question & Answers
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Biodiesel Dry Wash Purification
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