A review of fuel additives' effects and predictions on internal combustion engine performance and emissions

<abstract> <p>In recent years, there has been an increasing interest in additives for fuel research in the field of internal-combustion engine. Many studies have been conducted to improve the performance and emissions of the engine. Many kinds of additives in the form of solid, liquid, and gas have been used. The objective of this review is to examine the effects of having additives on the performance and emission of internal combustion engine. Additives such as alcohol, hydrogen, and metal oxides are proven to be successful to improve performance or reduce emission. Results from selected papers are discussed and summarised in a table. With the new development in nanotechnology, many researchers have shown an increased interest in carbon-based. In recent years, there has been an increasing interest in additives for fuel research in the field of internal-combustion engines. Many studies have been conducted to improve the performance and emissions of the engine. Many kinds of additives in the form of solids, liquids, and gases have been used. The objective of this review is to examine the effects of having additives on the performance and emissions of an internal combustion engine. Additives such as alcohol, hydrogen, and metal oxides are proven to be successful in improving performance or reducing emissions. Results from selected papers are discussed and summarised in a table. With the new developments in nanotechnology, many researchers have shown an increased interest in carbon-based nanoparticles such as multi-walled carbon nanotubes (MWCNT) and single-walled carbon nanotubes (SWCNT). Lately, with the discovery of graphene production techniques, graphene nanoplatelets (GNP) have also been applied as fuel additives. In addition to understanding the effects of the additives on the engine performance and emissions, researchers extended the research to predict the outcome of the performance and emissions. nanoparticles such as multi-walled carbon nanotube (MWCNT) and single-walled carbon nanotube (SWCNT). Lately, with the discovery of graphene production techniques, graphene nanoplatelets (GNP) also has also been applied as fuel additives. In addition to the understanding the effects of the additives to the engine performance and emissions, researchers extended the research to predict the outcome of the performance and emissions. The experiments involving the predictions efforts are summarised in a table. From the summary, it is found that the prediction of the GNP as fuel additive effects to the performance and emissions has not yet been explored. This gap is an opportunity for researchers to explore further.</p> </abstract>

Recycling of Rubber Wastes as Fuel and Its Additives

Economic, social, and urban developments generally require improvements in the transportation sector, which includes automobiles such as trucks, buses, trailers, airplanes, and even bicycles. All these vehicles use rubber tires. After consumption, these tires become waste, leading to enlarged landfill areas for used tires and implying additional harm to the environment. This review summarizes the growth of rubber recycling application and the sustainability of using waste rubber in the construction field. Furthermore, we provide methods to convert rubber waste to fuel or fuel additives by using tire-derived fuel and concentrate to pyrolysis, which are environmentally friendly and efficient ways. The related parameters such as temperature, pressure, and feedstock composition were studied. Most research papers observed that 500 °C is the optimal temperature at atmospheric pressure in the presence of a specific type of catalyst to improve pyrolysis rate, oil yield, and quality.

Operating of Gasoline Engine Using Naphtha and Octane Boosters from Waste as Fuel Additives

Fuel quality is an important indicator for the suitability of alternative fuel for the utilization in internal combustion (IC) engines. In this paper, light naphtha and fusel oil have been introduced as fuel additives for local low octane gasoline to operate a spark ignition (SI) engine. Investigated fuel samples have been prepared based on volume and denoted as GN10 (90% local gasoline and 10% naphtha), GF10 (90% local gasoline and 10% fusel oil), and GN5F5 (90% local gasoline, 5% naphtha and 5% fusel oil) in addition to G100 (Pure local gasoline). Engine tests have been conducted to evaluate engine performance and exhaust emissions at increasing speed and constant wide throttle opening (WTO). The study results reveal varying engine performance obtained with GN10 and GF10 with increasing engine speed compared to local gasoline fuel (G). Moreover, GN5F5 shows higher brake power, lower brake specific fuel consumption, and higher brake thermal efficiency compared to other investigated fuel samples over the whole engine speed. The higher CO and CO2 emissions were obtained with GN10 and GF10, respectively, over the entire engine speed and the minimum CO emissions observed with GN5F5. Moreover, the higher NOx emission was observed with pure local gasoline while the lowest was observed with GF10. On the other hand, GN5F5 shows slightly higher NOx emissions than GF10, which is lower than GN10 and gasoline. Accordingly, GN5F5 shows better engine performance and exhaust emissions, which can enhance the local low gasoline fuel quality using the locally available fuel additives.

A Rapid Compression Machine Study of 2-Phenylethanol Autoignition at Low-To-Intermediate Temperatures

To meet the increasing anti-knocking quality demand of boosted spark-ignition engines, fuel additives are considered an effective approach to tailor fuel properties for satisfying the performance requirements. Thus, screening/developing bio-derived fuel additives that are best-suited for advanced spark-ignition engines has become a significant task. 2-Phenylethanol (2-PE) is an attractive candidate that features high research octane number, high octane sensitivity, low vapor pressure, and high energy density. Recognizing that the low temperature autoignition chemistry of 2-PE is not well understood and the need for fundamental experimental data at engine-relevant conditions, rapid compression machine (RCM) experiments are therefore conducted herein to measure ignition delay times (IDTs) of 2-PE in air over a wide range of conditions to fill this fundamental void. These newly acquired IDT data at low-to-intermediated temperatures, equivalence ratios of 0.35‒1.5, and compressed pressures of 10‒40 bar are then used to validate the 2-PE model developed by Shankar et al. (2017). It is found that this literature model greatly overpredicts the current RCM data. The comparison of experimental and simulated results also provides insights into 2-PE autoignition behaviors at varying conditions. Further chemical kinetic analyses demonstrate that the absence of the O2-addition pathway of β-R radical in the 2-PE model of Shankar et al. (2017) could account for the model discrepancies observed at low-to-intermediated temperatures.

Solid Propellant Formulations: A Review of Recent Progress and Utilized Components

The latest developments in solid propellants and their components are summarized. Particular attention is given to emerging energetic binders and novel, ‘green’ oxidizing agents and their use in propellant formulations. A brief overview of the latest reports on fuel additives is included. Finally, a summary of the state of the art and challenges in its development are speculated on.