Experimental Investigation of Diesel Engine Performance, Combustion and Emissions Using a Novel Series of Dioctyl Phthalate (DOP) Biofuels Derived from Microalgae

Abstract

Physico-chemical properties of microalgae biodiesel depend on the microalgae species and oil extraction method. Dioctyl phthalate (DOP) is a clear, colourless and viscous liquid as a plasticizer. It is used in the processing of polyvinyl chloride (PVC) resin and polymers. A new potential biofuel, hydrothermally liquefied microalgae bio-oil can contain nearly 11% (by mass) of DOP. This study investigated the feasibility of using up to 20% DOP blended in 80% diesel fuel (v/v) in an existing diesel engine, and assessed the performance and exhaust emissions. Despite reasonable differences in density, viscosity, surface tension, and boiling point, blends of DOP and diesel fuel were found to be entirely miscible and no separation was observed at any stage during prolonged miscibility tests. The engine test study found a slight decrease in peak cylinder pressure, brake, and indicated mean effective pressure, indicated power, brake power, and indicated and brake thermal efficiency with DOP blended fuels, where the specific fuel consumption increased. This is due to the presence of 16.4% oxygen in neat DOP, responsible for the relatively lower heating value, compared to that of diesel. The emission tests revealed a slight increase in nitrogen oxides (NOx) and carbon monoxide (CO) emissions from DOP blended fuels. However, particulate matter (PM) emissions were lower from DOP blended fuels, although some inconsistency in particle number (PN) was present among different engine loads.

The Latest Method for Surface Tension Determination: Experimental Validation

“…Then, either Equations ( 6)-( 8) or the Equations ( 9)-( 12) are solved. When capillary constant a is obtained from either of Equations ( 8), ( 10), or (11) and specific weights of both fluids are known, the surface tension value may be determined from Equation (5). The solution is done in a spreadsheet which is attached in Supplementary Materials.…”

“…There are also plotted two reference surface tension values Çengel and Cimbala [33] as well as The International Association for the Properties of Water and Steam (IAPWS) [36] experimental data, which both are used as the benchmark values to validating the experimental results. When capillary constant a is obtained from either of Equations ( 8), ( 10), or (11) and specific weights of both fluids are known, the surface tension value may be determined from Equation (5). The solution is done in a spreadsheet which is attached in Supplementary Materials.…”

“…Since new created substances take part in energy transfer, they thermodynamic properties, including surface tension, must be determined. In addition, surface tension is one of the parameters that determine the combustion efficiency [2][3][4][5]. It is also an important property of the new synthesized surfactants that are applied during the fuel processing [6,7].…”

A Wavelet-Based Diagnostic Framework for CRD Engine Injection Systems under Emulsified Fuel Conditions

“…Most studies suggest the use of surfactants to enhance emulsion fuel stability and physio-chemical properties, yet their efficiency still depends on achieving appropriate hydrophilic-lipophilic balance (HLB) value [31]. Consequently, these phenomena have motivated several research studies on the quest for proper condition monitoring techniques for emulsified diesel fuel engines using the CR system [1,3,4,9,11]. By leveraging the vulnerabilities of CR systems to emulsified fuels, reliable condition monitoring frameworks can be developed.…”

“…Invariably, the need for emission control, improving diesel fuel efficiency, and extending the useful lifetime of engines have long motivated several improvement techniques. Among the diverse techniques available, diesel emulsification (in the right composition) has shown to improve the chemical properties of diesel fuels which in turn minimizes the quantity of pollution-causing agents that include nitrogen oxides (NOx), particulate matter (PM), and carbon monoxide (CO) [9]. The water in emulsified diesel fuel induces micro-explosions to form many small-sized emulsion droplets that enhance mixing.…”