Modified and Unmodified Jatropha Curcas Seed Oils as Pour Point Depressants for a Nigerian Waxy Crude Oil

Abstract

Transportation of waxy crude oil faces great challenges in pipelines, however, pour-point depressant could be employed to improve flow properties of waxy crude oil by modifying the morphology and structure of wax crystals. In this paper, modified and unmodified jatropha curcas seed oils was used as a green pour point depressants to evaluate the flow properties of a Nigerian waxy crude oil. Jatropha curcas seed oil (49.5%) was extracted using petroleum ether and the oil was analyzed for oil quality parameters (acid value, iodine value, free fatty acid and saponification value) and subsequently modified using diethanolamine and ethylene glycol to give fatty amides and glycol esters with sulphamic acid (2% and 10% respectively) as catalysts. The modified products were characterized using Fourier transform infra-red (FT-IR) spectroscopy. The modified and unmodified Jatropha seed oils were used treat a Nigerian waxy crude oil to determine their effects on the pour point of the said crude oil. This was done by determining the viscosity and pour point of the crude oil before and after it is dosed with different concentrations of the modified and unmodified Jatropha oils. The results revealed the efficiency of the fatty amides to reduce the pour point and viscosity of the crude oil from 180C to 150C and from 3.49 cst. to 2.0 cst respectively. Both ethylene glycol-modified Jatropha seed oil and the unmodified Jatropha seed oil were able to also depress the pour point of the crude oil to the same degree showing that modification with ethylene glycol did not improve the ability of ordinary Jatropha seed oil to act as pour point depressant.

Keywords

• Pour point;
• Crude oil;
• Jatropha;
• Fatty amides;
• Glycol esters;
• Viscosity