Quercetin rich compound and cardanol rich compound were extracted and modified via the William ether synthesis using 1,2-dibromoethane in the presence of a base catalyst. The FTIR spectral analysis of the modified product confirmed its chemical modification. The modified product MRCNSL was evaluated as emulsion breakers. Medium crude and seawater, 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 MRCNSL demulsifier was evaluated based on variation in dosage (10 ppm – 50 ppm), water content (10%, 30% and 50%), and solvent types (ethanol, butanol, xylene and a binary mixture of butanol and xylene in ratio 30:70, 50:50 and 70:30) at room temperature within a 3-hr period via bottle testing. Results obtained showed that water separation increases with demulsifier concentration and emulsion water content respectively, though water separation varied among the solvents. In conclusion, the evaluated MRCNSL product possesses emulsion breaking potential using binary mixture of Butanol/xylene (70:30) as solvent at shorter times. This may be due to the synergetic effect of Butanol as a solvent, thus, Butanol/xylene (70:30) should be considered as solvent substitute for xylene due to reduced cost and less toxicity levels, unlike using xylene alone which is toxic and expensive.