Re: Sun Break Processing

On 6/7/07, Jeff Brandt <jeffb-hD0ojMJ1hjDksvZKaRJZc1aTQe2KTcn/@public.gmane.org> wrote:

> We have processed 7 batches of fuel and have had very good success.
>

> Batch #6 - Titrated at 2.7ml, Used 8.12kg NaOH - Girlmark Formula
> Batch #7 - Titrated at 2.8ml, Used 8.22kg NaOH - Girlmark Formula
>

> Girlmark and others have suggested that the 3.5g base reaction
> quantity is wrong and 5g is closer to the real number. These numbers
> have been verified with GC testing.
>

> Infopop GC Formula (((titration ^ 1.1) + 5.0) * total litres)
>

> Then we proceed to process batch #7. This is were things got ... well

> different.
>
> There are several variables which changed with batch #7.
>

> 4) We ran out of NaOH and decided to use some NaOH that had survived
> our fire last year. It looked alright, but in retrospect.... perhaps
> not a good idea.
>

> I came back to find that the second sample also had considerable soap
> fall out. However there was something else that I have never seen
> before happening. The fuel was turning gelatin. Literally like jello
> shots.


Sooo .... the results are in ... where did we make our mistake?

Well, suspect #4: bunk NaOH turned out to be the culprit.

This wasn't just any sodium hydroxide, in fact it turned out not to be
sodium hydroxide at all. Some how we convinced ourselves that the
container we had left over from the fire was lye, when in actuality it
was anhydrous sodium sulfate.

We had experimented with drying fuel with the compound as it will
absorb 10 times its molecular weight in water.

When we made the methoxide we only used 3.4kg of good lye, and about
4.8kg of the anhydrous sodium sulfate.

During methoxide mixing the compound would have absorbed all of the
water produced by the NaOH + MeOH -> H2O + Na+ + MeO- reaction. The
solution was then inducted into the fuel that had additional amounts
of water.

Throughout the entire reaction the Na2SO4 was making bonds with water.
The sodium sulfate can share a bond with water. This is what causes
the solution to thicken into a jelly.

The good news is that we can recover from this.

We will need to get the sodium sulfate out of the biodiesel.

Since it is soluble in water we should be able to wash it out.

There is a large amount of excess methanol due to the incomplete
reaction. The methanol will foul up our washing. Methanol will absorb
water and in small amounts can act as a co-solvent and promote water
retention.

So ... we need to get the methanol out of the solution, wash, dry, and
reprocess.

We have been wanting to get our methanol recovery system going, so now
we have the perfect excuse to do it.

Dave is currently building an external heater for the system out of a
15 gallon stainless beer keg and a 5500 watt heavy duty heating
element.

The heater will be hooked in line from the output of the circulation
pump to the input on the top of the tank. We are welding 2" stainless
collars into the top and bottom of the keg to allow for a 2" T
stand-pipe style element arrangement. The other collar on the top of
the keg will be the exit port. This will prevent any air pockets from
forming in the keg.

We have our reactor setup like a pot still with a exit port on the top
of the tank leading to a copper condenser that sits in a 5 gallon
bucket of ice water.

We should be able to heat the solution to 165F and recover the
methanol through the condenser.

I'll then add warm water to the solution and manually stir the tank,
settle and drain until I can no longer detect Na2SO4 in the wash.

Then we will heat the solution to 220F to get rid of the water and reprocess.


--
Jeff Brandt
Sun Break Biofuels, LLC
mailto:jeffb-hD0ojMJ1hjDksvZKaRJZc1aTQe2KTcn/@public.gmane.org
503-317-4564