Glycerol Monooleate (GMO): a valuable biobased lubricity and pour point enhancer blend component for the ULSD fuel

Authors: SHAH, SHAILESH - The University Of Texas At Dallas; Liu, Zengshe - Kevin; Sharma, Brajendra - Bk

Submitted to: ACS Omega
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2023
Publication Date: 5/24/2023
Citation: Shah, S.N., Liu, Z., Sharma, B.K. 2023. Glycerol Monooleate (GMO): a valuable biobased lubricity and pour point enhancer blend component for the ULSD fuel. ACS Omega. 8(22):19503-19508. https://doi.org/10.1021/acsomega.3c00889.
DOI: https://doi.org/10.1021/acsomega.3c00889

Interpretive Summary: All commercial diesel fuel contains some amounts of sulfur, as the fuel is burned it is converted into a gas (sulfur dioxide) which has negative effects on both human health and the environment. The Environmental Protection Agency (EPA) has mandated that diesel fuel for transportation applications have an extremely low amount of sulfur. The solution seems simple: remove the sulfur from the fuel – problem solved. However, decreasing the amount of sulfur in diesel fuel creates issues with lubricity (premature fuel pump and injector wear) and cold flow properties (fuel turning into a solid at low temperatures) of the fuel. In this research, we report that Ultra-Low Sulfur Diesel (ULSD) fuel lubricity and cold flow properties were improved with the addition of a new soybean oil type derivative. This new soybean oil type derivative helped to reverse the negative side effects of using less sulfur as well as being cost-effective which makes it ideal as ULSD fuel enhancer which benefits the diesel industry.

Technical Abstract: Novel value-added usage of glycerol (biodiesel coproduct) derivatives has been indispensable due to the extensive production of biodiesel. The physical properties of ultralow-sulfur diesel (ULSD) improved with the addition of technical-grade glycerol monooleate (TGGMO) with increasing concentration from 0.01 to 5 wt %. The influence of increasing concentration of TGGMO was studied on the acid value, cloud point, pour point, cold filter plugging point, kinematic viscosity, and lubricity of its blend with ULSD. The results showed improved lubricity for the blended ULSD with TGGMO as shown by the reduced wear scar diameter from 493 to 90 µm. The low-temperature flow properties were also improved as shown by lower pour points of -36 °C for the 1% TGGMO/ULSD blend compared to -25 °C for ULSDTGGMO blends in ULSD of up to 1 wt %, which met the ASTM standard D975 specifications. We also investigated the blending effect of the pure-grade monooleate (PGMO, purity level >99.98%) on the physical properties of ULSD at a blend concentration of 0.5 and 1.0%. Compared to PGMO, TGGMO significantly improved the physical properties of ULSD with increasing concentration from 0.01 to 1 wt %. Nevertheless, PGMO/TGGMO did not significantly affect the acid value, cloud point, or cold filter plugging point of ULSD. A comparison between TGGMO and PGMO showed that TGGMO improves the ULSD fuel lubricity and pour point more effectively than PGMO. PDSC data indicated that although addition of TGGMO will lower the oxidation stability slightly, it is still better than the addition of PGMO. Thermogravimetric analysis (TGA) data showed higher thermal stability and lesser volatility for TGGMO blends compared to those for PGMO blends. The cost effectiveness of TGGMO makes it a better ULSD fuel lubricity enhancer than PGMO.