> Just wondering if anyone bothers much about methanol extraction, and > the whole issue about vacuum systems. > > Dave ..................
Yup. Some of us do. When running small batches, it may not seem to be of much consequence, but it's about 5 gallons for every 50 gallons of output. That's a boatload of toxic material to be flushing down the drain or washing into a field. Nothing like creating another dead zone on the farm. Approximately 2% of the recoverable methanol is in the biodiesel. This amounts to about half of one gallon in 300 gallon batches. The remaining 98% recoverable is in the glycerin and amounts to ~29.5 gallons. At $1.50 or more a gallon for methanol, you can see where recovery becomes cost effective rather quickly. The least energy intense method of recovery requires that the 120 degree reaction temp is never lost - not even during a separation period. This permits a rather quick jump up to evaporation temp for the alcohol, rather than starting from scratch. The only way to achieve this is with a well insulated system. For shadetree operations, simple R-19 Kraft faced insulation secured to the vessel(s) with 2" box tape does the trick. Larger reactors of several hundred gallons or more would need spray insulation, which can usually be acquired at any tank fabrication company. Not only does the insulation reduce energy input during recovery, but during the reaction as well. After all, one of the purposes of making biodiesel is to reduce fossil fuel consumption, yes? Todd Appal Energy [EMAIL PROTECTED] Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Please do NOT send "unsubscribe" messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
