Trying to compare CO2 vs ethanol for processing hemp at industrial scale (20+ lbs / hr) into a winterized crude oil and wanted to run it by you guys as a sanity check.
There were several things not included in the study since I don’t have a good way of estimating them. Would appreciate any input if someone has a good way to estimate the cost to run a C1D1 or C1D2 lab vs non-regulated lab, the cost to dispose of ethanol or biomass soaked with ethanol, and ethanol re-distillation or proofing
Summary
Throughput - Processing Power in kg biomass processed/hr
Cold Ethanol - 30 kg/hr
Warm Ethanol - 20 kg/hr
CO2 - 22 kg/hr
System Cost and System Cost vs Throughput
Includes extraction vessel, centrifuge/spinner, chiller, carbon filter, ultra low temp freezer where applicable
Cold Ethanol - $514,000 & $17,276 per kg/hr
Warm Ethanol - $455,000 & $22,244 per kg/hr
CO2 - $2.5M or $114,271 per kg/hr
Operating Costs
Excludes loss of cannabinoids, but includes cost of energy (electricity, natural gas, LN2), and solvents
Cold Ethanol - $111.06/batch, $2.04/kg, $3.73 per kg/hr
Assuming 2% solvent loss and ethanol is $11/gallon
Warm Ethanol - $41.95, $0.77/kg, $2.05per kg/hr
Assuming 2% solvent loss and ethanol is $11/gallon
CO2 - $135.49, $1.24/kg, $6.21 per kg/hr
Extraction Efficiency
Extraction Efficiency of solvent * solvent recovery
Cold Ethanol - 81% = 90% * 90%
Warm Ethanol - 86% = 95% * 90%
CO2 - 74% = 75% * 99%
Cost Assumptions
Electricity $0.08* /kWh
Water - $0.0026/gallon
CO2 - $2.75/kg
Ethanol - $10.00/gallon
Natural Gas - $14.76/MCF
Liquid Nitrogen - $1.89/gallon
Operating Cost Assumption
Electrical usage approximated by taking 1/2 of the maximum usage of the equipment (V * A / 1000)
Good analysis! I would think solvent loss would be a little less on warm ethanol than cold ethanol but otherwise everything looks about right (obviously, I don’t know what equipment is being spec’d though).
When you say that “redistillation costs are not included”, do you have “solvent recovery” in there?
I would assume so, but i don’t see it explicitly listed.
Turns out that many folks are able to strip 190proof off their extract in single plate stills (FFE, rotovap, moonshine still without reflux column).
So long as they don’t try and get all of it at once, and retire the last bit to “cleaning solvent”.
I’ve only looked at cold ethanol extraction (-20 or lower), and simple stills I’ve purchased or built. I always finished in a rotovap, and I segregated that solvent.
At $10gal I’m guessing you’re looking at heptane denatured ethanol.
Getting back exactly what you put in doesn’t seem to happen with that stuff. I haven’t had appropriate analytics to sort that out (can’t just use a proofing gauge) In any of the spots the owners insisted on using that stuff, but I’ve got a buddy who is an HPLC operator at an OR hemp facility who thinks he has.
Pretty sure I could use the SRI 410c MM in front of me to figure it out… if I wasn’t currently sourcing solvent from a local artisanal distillery (should check methanol levels )
CO2 - Extraction > Winterization > Ethanol Evaporation
Why does ethanol have to be retired from extraction to a cleaning solvent after re-proofing – it’s just not high enough anymore?
What other types of ethanol is there? I just looked for 190 proof ethanol. Is there something cheaper or better than heptane denatured ethanol? How do I know if it’s denatured ethanol?
One thing I might have overlooked is manpower. How many people are needed to man a large semi-automated ethanol system or a CO2 system?
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