another batch

last batch separated nicely, transferred fuel into holding carboy. started new batch, tried to heat oil outside in the sun, but it was too late in the day, so little effect was seen. ended up brewing in the traditional way, still using 110V AC hotplate. used 95g sodium hydroxide. methanol supply is running low (and oil supply) so need to stock up. 95g batch has settled nicely.

all WVO 15L batch

used a new decanter tool, made from a rieke spout cap glued into a PVC slip-on cap with black RTV silicone, but the glue melted in the end. design is good, just need better methanol resistant glue.

used solar/golf-cart batteries to power pumps, worked brilliantly. next need to try using 12v heater as well.

need to modify distiller stand so it will hold the methoxide carboy properly to get all the methoxide out. cut a slot into the end, add variable wedge support to tip up carboy.

process:
1. measure 15L (pre-measured) WVO into processor, heat to 130F
2. decant 3.3L methanol into carboy
3. measure 85g NaOH into 100mL glass beaker
4. add NaOH to methanol, bit by bit, swirling carboy in between
5. continue to mix methoxide while waiting for heat to reach 130F
6. heat passes 130F, but methoxide not well mixed enough, continue to mix, turn off heat
7. turn on pump, make sure oil is uniform temp
8. add methoxide by evacuating processor and pumping air into methoxide bottle
9. somewhat manual process, need to hold carboy sometimes and pump vacuum handle sometimes.. would be nice to automate
10. once methoxide bottle is empty, close valve
11. allow to mix for 10 minutes
12. turn off for 10 minutes
13. mix for 8 minutes
14. off for 8 minutes
15. mix for 8 minutes
16. decant into glass carboy, leave to settle

will check progress in the morning.

brew

3 successful batches so far, 0 duds.

batch 1 & 2:
15 L virgin soy
3.3 L methanol
75 g NaOH

process:
1. measure oil
2. decant oil into processor
3. turn on hotplate
4. measure methanol into 10L HDPE carboy (2nd graduation on back)
5. measure NaOH into paper baking cups (3 x 25g, 1st time; 1 x 50g & 1 x 25g, 2nd time)
6. add NaOH to carboy, decanting caps on, 3/16 hose connecting out-in ports
7. swish methoxide to mix, watch processor temp until 125 degrees F, running pump occasionally to keep uniform temp (5-10 seconds every minute or 2)
8. temp securely above 120, turn off/unplug hotplate
9. with processor pump running, attempt to inject methoxide into flow, slowly opening T valve. try pressurizing air in methoxide carboy, still not enough to promote flow. finally, close T valve and add methoxide thru vent port, opening processor cap to allow mixing. bad fumes and methoxide spill result.
10. re-setup methoxide carboy cap as vent, then seal rest of processor
11. run processor pump for 30-60 minutes, 5 minutes on, 5 or 10 off
12. decant into separation vessel (plastic carboy, 1st time; glass carboy, 2nd time)
13. allow to separate at least overnight
14. siphon biodiesel into separate (glass) carboy
15. pour glycerol into separate (plastic) carboy
16. siphon bottom layer biodiesel/glycerol mix into 1 gallon glass jug, allow further separation
17. decant biodiesel from 14 into fuel tank after passing thru 5u filter

results/notes:
fuel is golden color, feels & smells like biodiesel. still have not tested final pH, or other quality measurements. did not wash fuel. sloppy method for mixing methoxide, measurement of NaOH, and adding methoxide addressed in later batches.

3rd batch:
15 L used cooking oil from J restaraunt
3.3 L methanol
75 g NaOH

process:
1. measure oil
2. decant oil into processor
3. turn on hotplate
4. measure methanol into 10L HDPE carboy (2nd graduation on back)
4a. extract a few mL of warm oil
4b. titration:
4b-i. add 10 mL 99% isopropanol, 3 drops phenolphthalein, a few drops of 0.1% NaOH soln until color change is stable to 100 mL glass beaker, stirring with glass rod
4b-ii. add 1 mL oil
4b-iii. add 0.1% NaOH soln, 0.5 mL at a time, until color change is stable, in this case it was less than 1 mL, so use the same recipe as before (5 g/L)
5. measure NaOH into 100 mL glass beaker (easier to handle than paper)
6. add NaOH to carboy, put decanting caps on, 3/16 hose connecting out-in ports
7. swish methoxide to mix, watch processor temp until 125 degrees F, running pump occasionally to keep uniform temp (5-10 seconds every minute or 2)
8. temp securely above 120, turn off/unplug hotplate
9. with processor pump running, inject methoxide into pump flow, slowly opening T valve. pressurize air in methoxide carboy, evacuate air from processor top into methanol reclamation still. open valve bit by bit until methoxide bottle is empty.
10. close methoxide valve, keep still attached to vent.
11. run processor pump for 30 minutes, 5 minutes on, 5 or 10 off
12. decant into separation vessel (plastic carboy, 1st time; glass carboy, 2nd time)

results:
so far, good separation is noted. fuel is amber color, much darker than virgin fuel. much happier with handling of NaOH and methoxide, feels much safer than before. no spills this round, except for some portion of oil while measuring, and a little finished product came out of the top during processing.

first 15 L batch settling

last night, measured out 15 L of soybean oil into the processor, then let it sit overnight to check for leaks. there is a very slow leak, but it should be remedied by some teflon tape and an extra 1/4 turn (all fittings were made hand tight). today, measured 3.3 L methanol and added 75 g lye in a 10 L carboy, put the lids on and swished it around. at the same time, oil was heating up to 125 F. once methoxide was completely mixed (i.e. no more little chunks in the carboy), plumbed it to the processor and opened the valves, but it doesn't flow in easily. will need some sort of system to evacuate processor and push methoxide in. also, need plugs for all flanges and some easier method for decanting.

compiling equipment, building processor

found 2 tight head 5 gallon steel buckets. started turning one into a processor, attached 3 pipe flanges using #14 sheet metal screws and silicone metal epoxy. put together some other plumbing as well.. restrictor for inserting thermometer, and methoxide T and valve.

Getting it Together

last friday, picked up 5gal methanol from ERC in san leandro. also found a bottle of Red Devil lye in OSH, and 2x35 lb of soybean oil (little less than 9 gallons) at costco.

on order:
o phenolphthalein pH indicator
o steel 5 gal pail with lever lock lid
o "drug dealer" scale (accurate to 10th of gram up to 500 gram)
o hot plate
o 12" turkey fry dial thermometer
o 10 L HDPE carboy (x 3)
o 1 L HDPE bottles (graduated, x 2)
o 100 mL beakers (x 12)
o 50 mL graduated cylinder
o stirring rods
o 20 cc syringe (x 10)
o goggles, aprons, gloves (x 3)

still need:
o isopropyl alcohol (at least 70%)