I was almost inevitable. The feed stock for this batch comprised of two years worth of dregs from the bottom of my settling tank, 40 ltrs of palm and the balance the liquid off the top of several other palm drums. So it was no surprise that this batch despite a long period dewatering at over 100°C went to jelly during the first stage of a two stage process.
I did a titration just to find out what I was dealing with and it came out at 4.5 NaOH. Continuing my reduction of ASM I used a base of 2.25 and slightly overdosed the methanol.
The jelly wasn't too bad, so I left the system running with heat whilst I had a little think. Based on things I'd observed previously when batches showed signs of gelling, but recovered without intervention, I thought I'd try something I'd not done before, I added more catalyst. This shopwed signs of working on samples where I grossly overdosed the catalyst, so I set about adding small amounts of methanol and ASM. I did this until the colour chanced from that yellow ochre goo to a much darker, more normal brown/black.
I was running the processor with heat and it was sitting at a stead 64°C controlled by the PID. As soon as the colour changed, the viscosity dropped and the temperature rose by three degrees.
A 3/27 test showed an 84% conversion, so I drained the glycerine and ran a second stage as normal to convert the 16%. It all seems to have worked out OK.
Anyone else recovered jelly by adding catalyst? Seems completely the wrong thing to do!
