Refining Processes Handbook - 2020 - 114

2020 REFINING PROCESSES HANDBOOK
PROCESS CATEGORIES

COMPANY INDEX

BIOFUELS

Supercritical Biodiesel
Application: Produces biodiesel economically from any feedstock, such as used
cooking oil, corn oil and tallow.
Description: The feedstock, which normally contains at least a portion of fatty acid, is
combined with an alcohol, preferably methanol. This mixture is fed to a high-pressure
pump to increase the pressure and is then heated to elevate the temperature above
the critical point.
The now supercritical mixture enters the reactor, which allows for the products
to sufficiently react with a majority of fatty acids and fatty acid esters (glycerides,
sterol esters, etc.) to produce fatty acid methyl esters and glycerol. This does not
require the use of any catalyst. The reacted mixture leaves the residence bed and
enters the economizer to cool. The economized, reacted mixture then proceeds to the
back-pressure regulator where the pressure is reduced to atmospheric pressure. This
situation allows for immediate flashing of a vast majority of alcohol and water, which
proceeds to downstream separation and recovery of alcohol for recycling as a reagent.
The temperature of the remaining crude lipid stream undergoes cooling via heat
exchanger and enters the decanter. This decanter is where the vast majority of glycerol/
water/alcohol (bottom phase) are removed from the lipid stream (top phase). Since the
bottom phase contains virtually no salt, the downstream upgrading of crude glycerol is
vastly improved vs. conventional transesterification systems where salt is present. The
wet lipid stream proceeds from the decanter to the dryer where virtually all water is
removed. The dry lipid stream next enters the fatty acid ester (i.e., FAME) recovery unit.
Products: Distilled FAME compliant with ASTM D6751 and premium crude glycerin
(no salts).
Advantages: Innovative, yet proven referenced technology in operation since 2017;
simple design; easy to operate; higher quality products, such as distilled biodiesel and
crude glycerin (no salts); the option to retrofit to existing facilities; feedstock flexibility
(e.g., used cooking oil, corn oil, acid oil, tallow); and attractive economics.
Economics: CAPEX is comparable to conventional biodiesel for low-quality feedstocks.
Typical data for 300-tpd plant:
Feedstock:
320 tpd
Methanol:
29 tpd
Distilled biodiesel:
300 tpd
Premium crude glycerin:
42 tpd

Oil/fats
313 tpd

Supercritical biodiesel

Methanol
31 tpd

Distilled biodiesel
300 tpd
Premium crude glycerin
33 tpd

Other costs (utilities, chemicals, labor, maintenance): $4 MM/yr (for a US-based,
300-tpd plant)

Utilities: Heating oil and electric power
Development/delivery: Technology development started in the 2010s. A pilot plant
is in operation in the U.S. (mostly used for R&D purposes). A commercial plant has
been operated by Wilmar since 2017 in Taizhou, China.
Installations: One plant in operation
References:
1. Sturm, E., "Making biodiesel profitable without tax credits?",
Biodiesel Magazine, January 2020.
2. Tegen, M. "Wilmar implements Inventure supercritical technology
in China," Biodiesel Magazine, June 2018.
3. Sutterlin, R., "Supercritical biodiesel and soap carbonate technologies,"
AOCS, Minneapolis, Minnesota, 2018.
Licensor: Air Liquide Global Engineering & Construction (under license by
Inventure Renewable Inc.)
Website: https://www.engineering-airliquide.com/
Contact: inventure@airliquide.com

http://www.hydrocarbonprocessing.com/ https://www.engineering-airliquide.com/

Refining Processes Handbook - 2020

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