Fuels dispersed with engineered nanoparticle additives, or nanofuels, are desirable for the vastly different combustion properties such as combustion rate and ignition delay they exhibit compared to base fuels. The stability of such nanofuels over time and under different particle loadings is a very important parameter to consider before they can be put into practical use. Many techniques exist today to analyze suspension stability, which have been developed to analyze water-based nanofluids. Sometimes these techniques can be expensive, and/or require specialized equipment, and/or require a method that is invasive and disturbs the suspension. Present research uses a non-contact, non-invasive, low-cost experimental setup to analyze suspension stability over long periods of time. Nanofuels made from carbon-based nanomaterials (acetylene black, multiwalled carbon nanotubes) and metal oxide nanomaterials (copper oxide, aluminum oxide) with hydrocarbon fuels (canola biodiesel, petrodiesel) have been prepared and their settling rates have been analyzed over the period of three days. It is found that metal oxides go through several metastable states as they settle. The effect of initial concentration and liquid column height is shown. It is hoped that present research showcases the positive traits of the presented technique and will spark further interest in nanofuel stability. Number of words: 198
Biodiesel has proved to be an attractive alternative fuel for the compression-ignition engine, with its blends of regular petrodiesel being sold at virtually every gas station in the United States. Researchers have explored many of its combustion properties and sought to modify them in the interest of better fuel economy, specific fuel combustion, and lower emissions. The emulsification of biodiesel with water in order to promote microexplosions during the combustion process is one such fuel modification method. Microexplosions fragment the fuel droplet into many smaller droplets, which promote homogeneous combustion, and can result in smoother power output and better fuel economy. Present research analyzes the droplet combustion properties of soy biodiesel with 10% water and 0.1% POLYOX™ polymer. A sub-millimeter droplet is suspended on three 16μm silicon carbide wires and ignited using hot wire loops. The combustion process is recorded at 1000 frames/second by a high-speed CCD camera. Combustion behavior of the emulsified fuel is then analyzed by post-processing the resulting high-speed images. Results show several microexplosion events. Combustion trends are plotted, and combustion rates are determined. Burning rate for the emulsion was found to be very close to that of base fuel, with 2.1% decrease noted. It is hoped that present research will spark further interest in the fuel behavior modification of biodiesel.
The combustion of liquid fuels emulsified with water have long generated interest in the internal combustion engine research community. Typically, these fuels consist of small quantities of water emulsified with ultrasonification or other mechanical methods into a pure or multicomponent hydrocarbon fuel. These emulsion fuels promise significant advantages over base liquid fuels, such as better fuel economy, colder combustion temperatures, less NOx emissions, and so on. However, a significant practical disadvantage of these fuels is that they are prone to phase separation after they have been prepared. Till date, an objective but economical method of identifying the various degrees of phase separation has not been identified. Present research presents such a method and shows its utilization in analyzing the stability of water and hydrocarbon fuel emulsions over time without the addition of chemical stabilizers. It is expected that present research will pave the way in establishing this method to study the stability of other specialized multicomponent fluids.
The emulsification of water with liquid fuels to modify combustion characteristics has been of great interest to the combustion research community for some time. The emulsions are usually comprised of only water combined via ultrasonification (or other mechanical methods) with a base hydrocarbon fuel. These emulsions show improved combustion characteristics, such as lower combustion temperatures, and lower emissions. One of the main issues with these emulsions, however, is that these emulsions are not stable and are prone to phase separation over time, which inhibit the economic viability and practical application of these fuels. There are a multitude of ways being researched to improve fluid stability, including new mixing techniques, the addition of nanoparticles, as well as the addition of other fluids. The addition of ethanol to water-based emulsions has been shown to decrease the size of water droplets in the emulsion, allowing for a more homogenous mixture. With the aviation industry being a sizeable source of the global emissions caused by transportation, methods of lowering the emissions of aviation fuels as well as greener alternatives are needed. Present research quantitatively studies how the addition of ethanol to water and jet fuel emulsions affects the stability of the emulsion. A non-invasive, quantitative, and economical method for determining phase separation is used to study the stability of these multi-component mixtures. The system periodically measures the phase separation of the fluid column by automatically shining light through the fluid and detecting how much interference is created by the fluid. The system does this at five different depths of the fluid so the phase separation of the emulsion can be tracked in more detail. Ethanol and water are studied at mixtures of 5%, 10%, 15%, and 20% ethanol by weight and 5% and 10% water by weight emulsified with jet fuel. It is expected that the present research will lay additional foundation for the future study of fuel emulsion stability, as well as spark additional interest in utilizing emulsions to improve fuels.
Recent studies have shown that the addition of nanomaterials to fuels can improve combustion characteristics. A downside, however, is that these mixtures are unstable and prone to phase separation. Finding stable nanomaterial-fuel mixtures are required to make these mixtures viable for practical use. Current research studied the stability of Renewable jet fuel combined with multiple nanomaterial additives being acetylene black, graphene nanoparticles, and multiwalled carbon nanotubes, at 1.0% w/w ratio. Results were compared with prior research and it was shown that renewable jet fuel had a similar effect on settling as soy biodiesel and the results indicated that the fuel’s bulk viscosity was not a major factor determining the stability of the nanofuel.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.