Design of Water in Diesel Emulsion Fuel using Computer-Aided Approach

Abstract

The diesel engine is the main source of exhaust pollutants, mainly nitrogen oxides (NOx) and particulate matter. Water in diesel emulsion (WIDE) is the best and most successful alternative fuel strategy to reduce emissions without modifying the engine. Previous research has used an experimental technique to determine fuel formulation, stability, and environmental impact. Due to the limited number of studies that can be conducted, it is difficult to determine the best formulation via trial and error. This work aims to develop a systematic methodology for the design of WIDE fuel formulations using computer-aided product design. Chemical databases and property model libraries for pure compounds and mixtures for fuel attributes were created explicitly for this study. This investigation consists of four steps. The first step defines the problem by identifying product properties and needs and translating them into physico-chemical parameters as target properties. The second step involves creating databases and property model libraries. A database for nonionic surfactants is created. The property models required for the target properties are retrieved from the property model library at this stage. Screening possible surfactants to be used as input for step 4 is the next step. The last phase is to create a possible WIDE fuel formulation that meets the required parameters. An economic evaluation of the possible formulation is made by comparing the WIDE fuel prices of different surfactants with SPAN 80 as a reference. As a result, six potential surfactants with 48 potential WIDE fuel formulations with water composition from 2% to 11%, diesel from 80.7% to 92.9%, surfactant from 0.1% to 0.46% and additive from 0.1 % to 1% proposed as potential formulations. All the formulations meet the desired parameters set in step 1. Using a computer-aided approach, two surfactants, diethylene glycol monododecyl ether and propylene glycol stearate, have promising potential new surfactants to explore because of the properties and lower price of up to 72.7% compared to SPAN 80. WIDE fuel can be presented as an alternative fuel for diesel engines due to its formulation.