GLYCERIN OPTIONS: SOAP, COMPOST, AND ANAEROBIC DIGESTION
Dickinson College Biodiesel Shop
Carlisle, PA
The Dickinson Biodiesel Shop
Introduction to glycerin byproduct
� Crude glycerin classified as a haz mat
� Complicates storage, transport, and disposal
� Worldwide glut of crude biodiesel glycerin
� Pays to have a plan before getting stuck with a problem
What to do with glycerin backlog?
� glycerin soap production
� composting glycerin
� creating biogas digesters
For starters, do methanol recovery!
Recover the methanol! It’s not much harder than
making biodiesel
Safe handling of glycerin with methanol
Option one: soap making
Using methanol-free glycerin to make soap
Step-by-step soap making
Step-by-step soap making
Step-by-step soap making
Soap recipes that work!
Liquid soap recipe1 L KOH based glycerin900 mL water61 g KOH
Solid soap recipe1 L NaOH based glycerin200 mL water30 g NaOH
Making bar soap is more difficult…
� Failed batches
� Sweating
Marketing Soap
� Methanol content: flash point test
� Soap survey
� The Dickinson shop’s marketing locations
� The Brown Soap Company
� http://www.thebrownsoapcompany.com
Option two: composting glycerin
� Is composting just disposal, or is there a benefit? Is there a detriment?
� Everyone says glycerin can be composted, but there is currently no conclusive data available
What is composting?
� Composting is aerobic digestion of organic wastes
� Composting is NOT dumping waste in a hole in the ground
Composting basics
Small scale: 3’x3’x3’ Large scale: 8’ windrow
Composting basics: ingredients
� “Greens and browns”
� C:N ratio of 30:1
� Moist, but not too wet
� Good structure to allow air flow and prevent anaerobic digestion
Glycerin composting basics
� Cover piles to prevent rain saturation; compostex fabric
Glycerin composting research
� Trial 1: 10 piles; base of hay mixed with cow manure
� Trial 2: 6 piles; base of wood chips mixed with horse manure
� Trial 3: 4 piles; base of fall leaves with waste food
Glycerin composting research:adding the glycerin
• Five Saturation levels established
100% = 18 gallons glycerin
75% = 13.5 gallons glycerin
50% = 9 gallons glycerin
25% = 4.5 gallons glycerin
0% = 0 gallons glycerin
Cucumber bio assay using trial 1compost and soil additives
Compost:potting soil
ratio
% saturation (glycerin)
1:0 0%, 25%, 50%, 75%,
100%
2:3 0%, 25%, 50%, 75%,
100%
1:3 0%, 25%, 50%, 75%,
100%
0:1 0%, 25%, 50%, 75%,
100%
Cucumber bio assay using trial 1 compost and potting soil
Data and preliminary analysis
Cucumber bio assay using trial 1 compost and vermiculite
Data and preliminary analysis
Berlese funnel bio assay using trial 1 compost
Temperature data from trial 3 piles
Temperature data from trial 3 piles
Option three: biogas digesters
� Anaerobic digestion of organic matter into biogas and soil additives
� Research being conducted for large scale production
� Contracting with Robert Crosby of Biorealis Systems (www.biorealis.com) for small scale production research
� First attempts show possibilities
� Further research is underway
� Inoculate
� Feedstock
� Processor Design
� Glycerin feed levels