Hello,

I am knee deep in the process of my first ever batch of biodiesel. First ever batch and I am using the apple turnover and trying to simulate some of the GL one day process.

During dewatering I found it took a very long time to heat from 68F to about 195F. I am using one element and 110V, 1500watts. Would running a 220 volt 4500 watt element on 110volt heat the oil faster? I understand that it will only produce 1300 watts or so at that voltage, but it appears to have more surface area than the 110V element. Ideally I would like to run 220volt power (it is available in the garage). With the apple turn over I can only run a single element.

The glyceral is now settling after the 5% prewash. It appear that I passed 27/3 test (no settling after an hour). Will be heating from 120-195F again to drive off excess methanol through the plumbers delight still. Probably won't be able to start until 6pm. I hope its not a really late night....

I am still looking for some input on this. In 3 hours last night I was able to drive the temperature of the prewashed-gly settled biodiesel in my apple turnover from 120F to 185F. In those 3 hours I collected just shy of 3 liters of methanol of unknown purity (don't have hygrometer yet). The batch was 90 liters of soy bean oil titrated at 1 with 24% methanol added.

I started adding air to the lower plumbing at the start of the third hour. The temp did not want to get above 190F.

Should I have expected more methanol recovery? If so, do I need to change my heating element (110V,1500W) to get more heat?

Hi jon

You had drained off the glycerol, had you? (Don't do a traditional distillation while the two are in the same container)

Was your pump circulating the biodiesel during the distillation?

If so, 3 litres methanol from 90 lires biodiesel is a good figure.

Graham,

I did a 5% prewash (circ for 15 minutes) settled for 90 min, and then drained as much as I could (about 25 liters or so of glycerine).

The pump (blue Harbor Freight) was circulating the entire time.

Would a beer/winemaking hygrometer work (I think I can dig one up in the basement) to determine the purity of the distilled methanol?

Jon, you can use a beer/wine hydrometer. These are designed for higher density fluids and will sink completely in alcohol. The trick is to extend the stem with a lightweight plastic drinking straw so that it floats. Just extend the calibration from the glass stem up the straw. You need quite a deep flask to accomodate it.

No matter how much you heat it, or how big your element is, the presence of the methanol limits the temperature.

This is analogous to the boiling point of water. Even if you put a blow torch on water, it won't get hotter than 212F.

Now, since you are heating a mixture, the maximum temperature will change (go higher) as the percentage of methanol in the mix goes down.

What you can accomplish with bigger/faster heat input, is to drive the methanol out faster. Your condensor will also have to remove that heat faster as well, or you will lose methanol vapor and maybe gas yourself. One way to tell is if the discharge end of your condensor gets warm/hot, that's a bad sign. It should stay cool, well below the boiling point of methanol.

HTH

troy

Thanks for that info. The bottom of the plumbers delight was cool to the touch. I think I may have gassed myself a little bit during the air injection part of the process. At one point I may have been putting too much air in. I could see a vapor cloud in addition to the dripping/running condensed liquid coming out. Does the presence of vapor (steam/cloud whatever you want to call it) indicate that I need to make process adjustments, or is that OK?

John,
I had the same problem when I started with my applesauce processor; IE takes too long to heat.
I solved it by "turbocharging the output of the Harbor Freight pump.

Check this out (look at pics #3 and #4 especially):

smcleod's turbo idea

smcleod uses 220v, but I just use 110v to run 2 220 elements. It takes me about 1.5 hours to heat up 30 gallons of WVO for processing (it used to take close to 3 hours!)

quote:

Originally posted by jon h.:
Thanks for that info. The bottom of the plumbers delight was cool to the touch. I think I may have gassed myself a little bit during the air injection part of the process. At one point I may have been putting too much air in. I could see a vapor cloud in addition to the dripping/running condensed liquid coming out. Does the presence of vapor (steam/cloud whatever you want to call it) indicate that I need to make process adjustments, or is that OK?

Visible vapor of any kind exiting the condensor is a BAD sign and is NOT ok. Use caution with your air injection system, as to how much and how fast you inject the air.

HTH,

troy

Hi Jon

Injecting air is not a good idea, because the air has to go somewhere, and when it leaves, it carries methanol vapour with it, because the condenser is not perfect.

Instead, why not think about a system something like this ....

http://www.london-electronics.com/bd/ecosystem/state_diagram_new.htm


It recirculates the same air continously in a closed loop, dragging it thru the condenser time after time. You don't add any extra air, so none escapes.

It is effective, speeds up recovery time and is simple and cheap to make. (I made it easily, and I'm left-handed AND penny-pinching by nature)

Any questions, let me know and I'll try to help.

I do want to get the venturi setup like you show Graham. My first couple of attemps have failed. Has anybody found a commercially available venturi that would work for this application?