Drying Biodiesel.

[Julian]

I've not tried silica gel to dry bio, but I've tried using it to dry methanol ... that doesn't work.  The silica gel appears to absorb the methanol in preference to water.  The silica gel never seemed to work effectively afterwards.

I have tried those horticultural water absorbing crystals to dry bio ... that didn't work either!  They just sat there in the end of a stocking and did very little after an initial small swelling ... (sounds all too familiar these days!).

I'm good at failures, me!

[dgs]

Most things get harder the older you get Julian.

[oakwoodtv]

I would be happy to manage to get small swelling at my age.

[Bill]

I'm good at failures, me!

During a TV interview with a theoretical physicist he said ' ... a negative result is as valuable as a breakthrough result, it serves to narrow the field of possibilities.'

[dgs]

That is virtually what IMB used to say, That a failed experiment can sometimes tell us as much as a successful one.

[therecklessengineer]

I'd argue that it's possibly more so as it combats confirmation bias.

[dgs]

I recently ran a drying cycle and monitored the r/h and temperature as read by the sensor, together with the biodiesel temperature and did a s/b water test each hour. Here are the results.

Time      Bio temperature       r/h-sensor      temperature-sensor    water s/b

start              65degs                50%                      26.3                  860ppm

+1 hour          66degs                42%                     27.4                  400ppm

+2 hours         66degs                36%                     27.5                  180ppm

+3 hours         67degs                30%                     28.5                  130ppm

+4 hours         67degs                28%                     29.0                  120ppm

The exiting air temp will slightly alter the r/h which could be corrected but I think the correlation is pretty accurate. I have now started to only use a 3 hour cycle as there is not much drying taking place during the last hour. if graphed the drying curve would be very exponential.

[Julian]

Excellent stuff, Dave!

Did you get the Arduino and LCD working?
What sensor did you end up using?
Have you tried the sensor directly in the biodiesel?

If you are running the Arduino, can I send you one of the cheap sensors I've been playing with?  Quite happy for you to dunk that in bio.

[dgs]

No, I haven't tried the sensor in bio, it's just the cheap one with the readout that I am using. By all means send me the sensor which i will try on the arduino (which I will get operational this week, promise) so get ready for some PM's, Cheers.

[Julian]

This is the DHT11 sensor and how to connect it to the Arduino.

Do you want me to include the resistor too and can you PM me your address?

[dgs]

PM sent.

[Julian]

Ok, it's on its way to you.

I popped in some small dia heat shrink so you can cover the solder connections.

It'll be very interesting to see how it relates to the SB measurements.

[dgs]

Indeed it will.
I've been thinking about getting some new titrant and solvent for the KF. It's an instrument that should really be in daily use and I don't really use it enough to justify spending about £150 with sigma aldrich.

[slabster]

I've not tried silica gel to dry bio, but I've tried using it to dry methanol ... that doesn't work.  The silica gel appears to absorb the methanol in preference to water.  The silica gel never seemed to work effectively afterwards.

I have tried those horticultural water absorbing crystals to dry bio ... that didn't work either!  They just sat there in the end of a stocking and did very little after an initial small swelling ... (sounds all too familiar these days!).

I'm good at failures, me!

A molecular sieve works for Methanol. I will dig out the link for it. slabs

[slabster]

Looking for a schematic plan to demeth / dry freshly reacted bio in an inert atmosphere hopefully via the reactor / venturi....