Published on Sep 05, 2023
The objective: This project investigates the potential of five plant oils as alternatives to petro-diesel, with the primary objective to investigate the added value, if any, resulting from trans-esterification of these oils into bio-diesel
Avocado, camelina, castor, coconut and palm oils, as well as their methyl-esters were studied for:
i) physical properties of viscosity, freeze point, density, and pH;
ii) fuel performance; and
iii) comparative economics versus petro-diesel.
Physical and chemical characteristics were measured using traditional techniques.
Fuel performance was tested using a modified diesel generator and placing a constant load on the generator over a timed constant interval run and hen measuring the fuel consumed in grams.
Grams consumed over a test period was then converted to an equivalent miles per gallon in terms of percent efficiency relative to the petro-diesel baseline.
In addition, aged avocado oil was tested to investigate a potential drawback of bio-fuels, oxidative stability.
Based upon physical and chemical properties, castor, coconut, and palm oils were eliminated as viable alternatives.
However, all bio-diesels, including those of eliminated oils, proved viable, though coconut and palm diesels are constrained to serving as warm weather fuels.
In evaluation of energy efficiency relative to petro-diesel, testing indicated a baseline performance of 131 grams diesel consumed, which was converted to a base equivalent of 42.0 mpg.
Fuel efficiency of petro-diesel was followed by avocado and its bio-diesel at 38.4 mpg, then camelina and its bio-diesel at 38.3mpg and 38.4 mpg.
These were followed by the remaining bio-diesels, with the worst performing fuel tested, castor bio-diesel at 34.3 mpg
For four of five fuels, conversion from oil to bio-diesel was an improvement in physical characteristics and performance.
Camelina was the exception. Trans-esterification of camelina and avocado proved economically and environmentally unjustified though.
Those two oils, as well as all five bio-diesels were found to be superior to petro-diesel in terms of environmental impact, and competitive with petro-diesel in performance measured on cost per mile basis.
Furthermore, these can be produced at scale to be a measurable component of the total U.S. energy supply allowing for the potential for a substantial reduction in global CO2 emissions.
This project investigates the potential of five plant oils as alternatives to petro-diesel, with the primary objective to investigate the added value, if any, resulting from trans-esterification of these oils into bio-diesel.
