Recent patch of biomass we are working through i’m seeing higher 2nd pass vacuum levels than my 1st pass. Running a single stage stainless WFE and extracting CBD Hemp biomass
Cold ethanol extracted -40C denatured ETH
Decarb in 50L jacketed reactor taking it up to 138C @ which point light terpenes are coming off.
1st pass on the wiped film running evap:132-135C/condenser:100C 375RPM. Vacuum ~35-40 micron -75 CT
-1st pass I’m pulling about 6-7% volatiles off and about about another 6% as heads.
2nd pass on the wiped film running evap:162-165C/condenser:100C 425RPM. Vacuum 42-46 micron -75 - -80 CT yielding 73-76% to distillate from start material here.
been playing around with increasing the 1st pass temp from 132-135 but doesn’t change anything on the 2nd pass and just creating more SPD cleanup of the heads coming off which yield pretty high to distillate already.
Been keeping it in the mid 20’s for the 2nd pass in the past but for the past month or so we are just seeing it climb way past there when begin feeding. I’m happy with the output overall… i’m thinking the obvious answer is some fraction in the 140-160 range coming off but cold traps are bone dry. Anyone got any experience with this ?
Your second pass material will be thicker than the first pass which in turn will give you a higher vacuum. I get 200-350mtorr on first and 100mtorr or less on second pass.