Optimization on preparation process parameters of glucose solutions emulsified diesel

Abstract: In order to study the stability and fuel economy of glucose as a substitute for diesel fuel, this paper presented an experimental scheme and experimental procedures for the stability test of glucose solution emulsified diesel based on the design of experiment (DoE).The effects of glucose which instead of alcohol fuels on stability of glucose solution emulsified diesel were developed. Glucose solution emulsified diesel, a kind of potential renewable energy which is clean and environment-friendly, can be used as fuel in diesel engine directly. It not only improves the performance and emissions of diesel engines, but also can be applied to diesel engines without any modification. Glucose solution emulsified diesel is a mixture with glucose and water, which is experienced with stratification, flocculation, coalescence and demulsification process, the stability of the emulsified fuel products is an very important factor for its large scale application. At the same time, the choice of emulsifier, latent solvent and hydrophilic and lipophilic balance (HLB) value are important parameters which can affect the stability of glucose solution emulsified diesel. In this paper, the impacts of emulsifier types, HLB value, dosage of emulsifier, types of latent solvent, dosage of latent solvent, dosage of glucose aqueous solutions and dosage of glucose in solutions on the stability of glucose solution emulsified diesel were studied. According to HLB theory and emulsification principles, compound reagents instead of single reagent were selected as emulsifier on stability of glucose solution emulsified diesel, and the preparation experiments and the scope of the value were determined. Reagents scope were as follows: HLB value 5-6.5, Span80 and Tween80 as compound reagents, castor oil as latent solvent, glucose aqueous solutions 10%-25% and glucose in solutions 10%-25%. A response surface model based on test data was constructed using the software Design-Expert. Resorting to the response surface model, stability time of emulsified fuel was obtained and preparation parameters of glucose solution emulsified diesel were optimized. The optimum processing of glucose solution emulsified diesel was: compound reagents 2.43%, castor oil 1.08%, pure diesel 81.49%, HLB value 5.77, aqueous glucose solutions 15% and glucose in solutions 16.83%. In this condition, it could stay stable without separation in a plug tube at room temperature for 264.2h. In order to improve the accuracy of the characteristic test, parameter of the optimal processing was kept one significant digits after the decimal point as the following: compound emulsifier 2.4%, castor oil 1.1%, pure diesel 81.5%, HLB value 5.8, aqueous glucose solutions 15% and glucose in solutions 16.8%, and it could stay stable without separation in a plug tube at ambient temperature for 252 h, which has 4.62% error component with software simulation value. The experiment was carried out on an automotive diesel engine fuelled by glucose solution emulsified diesel and pure diesel with the method of European stationary cycle (ESC). The result showed that fuel consumption of glucose solution emulsified diesel was 238.14 g/(kW·h) while that of pure diesel was 205.70 g/(kW·h). Based on the optimal processing parameters, the cost of glucose solution emulsified diesel was calculated. the calculation result was as follows: economy characteristics of glucose solution emulsified diesel costs 1.786 yuan and that of pure diesel costs 1.598 yuan. This consistent with our expectation that this study will assist in support of industrial development and application of the glucose solution emulsified diesel.