Synthesis and Evaluation of Ethanolamine-Cashew Nut Shell Liquid Products as Crude Oil Emulsion Breakers

Abstract

Cashew Nut Shell Liquid (CNSL), a natural phenolic liquid, was extracted from cashew nut shells using acetone and derivatized using Ethanolamine (EA) and Diethanolamine (DEA) in varying molar ratios via a one-pot process into anacardic acid-based ethanolamine esters and evaluated for use as crude oil emulsion breakers. The CNSL extract was characterized for its physico-chemical properties, FTIR spectral analysis for CNSL and the derivatives confirmed its chemical modification. Medium heavy crude and seawater sampled and characterized with ASTM standards were used in producing laboratory-simulated crude oil emulsions at varying crude oil: water mixing ratios of 90:10, 70:30 and 50:50. Performance of the anacardic acid-based CNSL extract and derivatives as demulsifiers were evaluated based on variation in dosage (10 ppm – 50 ppm), water content (10%, 30% and 50%), and solvent types (xylene and butanol, BuOH) at 60℃ within a 3-hr period via bottle testing. The performance of effective demulsifier formulations were compared with a commercial demulsifier, Phase Treat-4633, PT-4633, under similar conditions. Results obtained showed that water separation increases with demulsifier concentration and emulsion water content respectively, though water seperation varied among the demulsifiers as concentration and water content increased. PT-4633 in butanol achieved efficient water separation with an optimal seperation (100%) observed after 5 minutes at 40 ppm and 50 ppm, 50% and 60℃. In conclusion, the evaluated ethanolamine-CNSL products possess emulsion breaking potential using BuOH as solvent at shorter times. This behaviour may be due to the synergetic effect of BuOH as a solvent, thus, BuOH should be considered as solvent substitute for xylene due to low cost and toxicity levels, unlike xylene which is toxic and expensive.