Phase behavior of bicontinuous and w/o diesel microemulsions using nonionic surfactants combined with hydrophilic alcohol ethoxylates.

Abstract

Bicontinuous and water in diesel microemulsions were formulated using single nonionic alkyl poly glycol ethers combined with hydrophilic alcohol ethoxylates. The phase behavior at temperatures ranging from 0 ~ to 50 was investigated. Visual inspection as well as cross polarizers were used to detect anisotropy. The fish phase diagrams were determined. The presence of the hydrophilic alcohol ethoxylates was necessary to initiate both types of microemulsions. Increasing the hydrophobic chain length of the surfactant led to a wider range of temperature stability at lower surfactant concentration. Meanwhile increasing the ethylene oxide units in the head group by two units led to a phase diagram that is dominated by lyotropic liquid crystal. The formulated water in diesel microemulsions were tested experimentally in a 4-cylinder diesel engine, from which it is observed that the emissions of NOx, soot, and CO2 were reduced substantially compared to neat diesel, while for the CO the reduction occurs just at low load.