Preparation of diesel-water blends with binary emulsifier systems for use in diesel engines

• Main Authors: Cokaliong, Casey M., King, Jerome Spencer S.
• Format: text
• Language: English
• Published: Animo Repository 2016
• Subjects: Diesel fuels; Heat-engines; Water; Chemical Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/14927
• Institution: De La Salle University

Diesel engines have long been regarded as a significant contributor to air pollution as it exhausts several hazardous pollutants. As such, the goal is to reduce these emissions and pollutants without compensating the efficiency of the engine. A solution to this problem is by using water-in-diesel emulsions (WiDE) as the alternative fuel to be placed in the engine.The researchers compared the results produced using two different binary systems of emulsifiers: (1) SPAN 80 and TWEEN 80, and (2) SPAN 60 and TWEEN 60. The diesel used is a blend prepared with 2% biodiesel in the form of coconut methyl ester. The water content of the system was fixed at 5%, with a high speed homogenizer being used to incorporate the emulsions at a fixed rotation speed. The prepared solutions were tested for long term stability using visual and turbidimetric analyses. The emulsions prepared using SPAN 80 and TWEEN 80 were satisfactory but SPAN 60 and TWEEN 60 failed to produce any stable solutions. The reason for this is likely due to the use of a biodiesel blend, as biodiesel is soluble with the former pair of emulsifiers but insoluble with the latter.The solutions prepared using SPAN 80 and TWEEN 80 were tested for physical properties, to check whether the properties are comparable to that of the properties of diesel. These properties include density, viscosity, higher heating value, distillation temperature range, flash point, cloud point and pour point. The physicochemical properties of the biodiesel blend and emulsions could be explained in terms of the molecular behavior of the micelles. However, the emulsions' viscosity failed to satisfy the standards set by both ASTM and PNS. This property was found to increase in value with the addition of any of following components of the emulsions: biodiesel, water and the emulsifiers. Hence, this needs to be counteracted by the addition of lower molecular weight hydrocarbons, removal of higher molecular weight hydrocarbons or decrease the emulsifier requirement. Nonetheless, changing the formulation would likewise change the other properties and care must be taken to ensure that none of the other properties would fail the standards after modification.