With Mark Imisides recent forum posts about his method I couldn't resist giving it another go.
Original thread is here;
http://www.biopowered.co.uk/forum/index.php/topic,3037.0.htmlI mixed up plenty of methoxide for the 100 litre batch so as not to disturb the CaO fines in the cubie bottom;
17 litres methanol, 800gms KOH, 1KG CaO x2
Cold reaction starting temp was 17.5 degsC mixed for 1 hour, end temp was 29.5 degsC
I did 2 stages and the total chemicals used were virtually the same as my usual KOH/ASM mix, eq to 6.2 gms KOH/litre and 13.5% methanol. Oil was glyc washed and showed 8.5mls dropout using 10/90 before processing.
The soap produced seemed to be lower than my normal process, after S2 I added only 1 litre of water and bubbled for only 4 hours to remove the watery glycerol, by this time the soap was down to <500ppm so I could do a hard water wash with the compressor.
The process did not stop the typical emulsified mono layer forming between the water and bio layers after settling. In fact I resorted to using a little acid on the last 2 washes.
The batch was left to settle overnight and dried the next day. I'm pleased to report the dried bio was clear and bright and free from any suspended calcium soaps.
The methoxide took me an extra 20 mins to mix, so the method hardly takes any extra time. Using the 50/50 mix of KOH/ASM means that for me this method isn't really an advantage, but for those on KOH only you will find an increase in yield, especially if you don't glyc pre-treat the oil.
As with other 'dry' methods I have tried glyc out is about 2/3 of methoxide in due to very little soap being formed to increase the glycerol volume.
