Glycerin Purification


Crude glycerin on the left was purified from the waste in the center to the water-white glycerin on the right.

Crude glycerin on the left was purified from the waste in the center to the water-white glycerin on the right.


Glycerin Purification from Traditional Biodiesel Processes

For every nine pounds of biodiesel produced in any reaction, one pound of glycerin is also produced. The crude glycerin contains inorganic salts, heavies, solvent and water and is considered a hazardous waste as generated from most biodiesel processes. Artisan has developed a cost effective process to purify the glycerin from crude to fuel grade, tech grade, or USP grade, depending on the quality of the feedstock used in the process.


Artisan’s Glycerin Purification Unit (GPU) offers significant advantages over other glycerin purification systems:

  • Greener process and lower annual operating costs due to:
    • No use of steam sparge or high pressure steam used in jets to produce vacuum, which significantly reduces the annual energy consumption
    • No chemical treatment required which minimizes waste disposal and permitting requirements, over and above the rising cost of these chemicals
  • Operating costs as low as 1¢/lb of purified glycerin which is 1/3 that of typical deodorization processes and 1/10 that of membrane processes
  • Faster return–on–investment
  • Proven technology handling difficult separations for over 50 years
  • Simple 2–stage process requiring less equipment with 10:1 turndown capability
  • Can process wide variety of glycerin crudes (up to 40 – 50% solids/soaps) to produce higher yields in a single–pass for certain feedstocks compared to other technologies with less downtime for cleaning

Cost Comparison with a Competing Distillation Process
Plant size: 5 MM GPY crude > 99.0% product purity
Feed composition = 84 wt.% glycerin, 9.35% water, 6% NaCL, 0.055% MeOH

Competing process

Steam heat, steam sparge, steam jet vacuum system

Heating / Cooling Energy (MM BTU/hr) Steam Usage (lb/hr) Electric Power (kW) Annual Energy Cost ($MM) Line Item % of Total Energy Cost ($/lb)
150 PSI Steam 18,300 2.05 88%
Electricity for Process & Utilities 314 0.29 12%
Cooling Tower Load (for comparison) 13.8
Estimated Energy Cost per Year 2.34 $ 0.06

Artisan Process

2–Stage Rototherm evap. process w/rectif. column, mech. vac system

Heating / Cooling Energy (MM BTU/hr) Steam Usage (lb/hr) Electric Power (kW) Annual Energy Cost ($MM) Line Item % of Total Energy Cost ($/lb)
Hot oil heater (@ 1.3x est. duty) 4.8 0.40 66%
Electricity for process & utilities 223 0.21 34%
Cooling tower load (for comparison, @1.3x est. duty) 4.5
Estimated energy cost per year 0.61 $ 0.02
Annual operating cost savings of Artisan process: $1.7 MM
Capital savings of competing process: $1.8 MM
Assumptions includes: cost of steam @ $13.30/1000 lb/hr, heating @ $10/MM BTU (natural gas), electricity @ 11¢/kWh



Cost Comparison with a Competing Membrane Process
Plant size: 4.7 MM GPY crude > 99.0 % product purity, USP grade
Feed composition = 74 wt.% glycerin, 24% water, 0.05% MeOH, balance salts

Competing process

Chemical treatment, membrane technology, nanofiltration, and distillation

Annual Cost ($MM) Line Item % of total Operating Cost ($/lb)
Estimated total operating cost per year, including energy, pre & post treatment materials, and membranes 4.86 $ 0.17

Artisan Process

2–Stage Rototherm evap. process w/rectif. column, mech. vac system

Annual Cost ($MM) Line Item % of total Operating Cost ($/lb)
Hot oil heater (@ 1.3x est. duty) 0.30 64%
Electricity for process & utilities 0.17 36%
Estimated energy cost per year 0.48 $ 0.02
Annual operating cost savings of Artisan process: $4.4 MM
Capital savings of Artisan process: $1.5 MM
Assumptions includes: cost of heating @ $10/MM BTU (natural gas), electricity @ 11¢/kWh

Note: The above tables are part of a presentation, if you would like to see the whole presentation please contact us.