Course: BFM 202 Biodiesel Production

Lecture

Other Methods to Reduce High Viscosity Oils
Credits
BFM 202 Biodiesel Production Unit 3 Lecture has been adapted from "ENGY 131 Unit 3 Transestrification Made Simple" by Southeastern Illinois College.

ENGY 131 Biodiesel Production course content by Southeastern Illinois College is licensed under a Creative Commons Attribution 3.0 Unported License. Except where indicated otherwise.

Other Methods to Reduce High Viscosity Oils

Direct Use of Vegetable Oils and Blending

The use of crude vegetable oils as fuel has been attempted since the
diesel engine was invented. However, the use of “neat” vegetable oil
encounters operational problems due to its high viscosity which can
be 11-to-17 times higher than diesel fuel.

In 1893, Rudolf Diesel successfully demonstrated his diesel engine by
fueling it with peanut oil (a biomass fuel) and the possibility of
utilizing biomass fuel for engines was realized.

Polymerization lowers neat biodiesel fuel's volatility causing the
formation of carbon deposits in engines due to incomplete combustion.
These deposits results in oil ring sticking along with thickening and
gelling of the lubricating oils.

During the World War II, vegetable oils were used and tested in diesel
engines in Belgium, France, the United Kingdom, Germany, and Japan.
Blending biofuel with petroleum-based fuel became common but impractical
due to the decrease in power output and thermal inefficiency caused by the
carbon deposits.

Pyrolysis or Thermal Cracking

Pyrolysis is defined as the conversion of one substance into another by
means of heat in the absence of air or oxygen at temperatures range from
450 °C to 850 °C or by heat with the aid of a Lewis acid catalyst.

The Lewis acid catalysts used in this process include zeolites, clay
montmorrilite, aluminum choride, aluminum bromide, ferrous choride, and
ferrous bromide. However, the removal of oxygen during thermal
processing also eliminates the environmental benefits associated with
using an oxygenated fuel. In addition, these fuels are produced more
like gasoline.

Microemulsion

A microemulsion is technically defined as a stable dispersion of one
liquid phase into another with a droplet diameter approximately 100 nm
or less. The microemulsion process has been studied for use in biodiesel
production as a means to improve the viscosity of vegetable oils by
blending it with a simple alcohol, i.e, methanol or ethanol. However,
injector needle sticking, carbon deposits, incomplete combustion, and an
increase in the viscosity of lubricating oils were reported from fuel
produced using this process.