Glycerol Monooleate (GMO): A Valuable Biobased Lubricity and Pour Point Enhancer Blend Component for the ULSD Fuel

Novel value-added usage of glycerol (biodiesel coproduct)derivativeshas been indispensable due to the extensive production of biodiesel.The physical properties of ultralow-sulfur diesel (ULSD) improvedwith the addition of technical-grade glycerol monooleate (TGGMO) withincreasing concentration from 0.01 to 5 wt %. The influence of increasingconcentration of TGGMO was studied on the acid value, cloud point,pour point, cold filter plugging point, kinematic viscosity, and lubricityof its blend with ULSD. The results showed improved lubricity forthe blended ULSD with TGGMO as shown by the reduced wear scar diameterfrom 493 to 90 mu m. The low-temperature flow properties werealso improved as shown by lower pour points of -36 degrees Cfor the 1% TGGMO/ULSD blend compared to -25 degrees C for ULSDTGGMOblends 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 ULSData blend concentration of 0.5 and 1.0%. Compared to PGMO, TGGMO significantlyimproved the physical properties of ULSD with increasing concentrationfrom 0.01 to 1 wt %. Nevertheless, PGMO/TGGMO did not significantlyaffect the acid value, cloud point, or cold filter plugging pointof ULSD. A comparison between TGGMO and PGMO showed that TGGMO improvesthe ULSD fuel lubricity and pour point more effectively than PGMO.PDSC data indicated that although addition of TGGMO will lower theoxidation stability slightly, it is still better than the additionof PGMO. Thermogravimetric analysis (TGA) data showed higher thermalstability and lesser volatility for TGGMO blends compared to thosefor PGMO blends. The cost effectiveness of TGGMO makes it a betterULSD fuel lubricity enhancer than PGMO.