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>

Liquid-Phase Exfoliation of Graphene in Organic Solvents with Addition of Picric Acid

In this work, graphene was produced by liquid-phase exfoliation of graphite in different organic solvents with addition of picric acid. The graphene was easily produced by one step ultra-sonication of graphite powder in the organic solvents. The addition of picric acid has increased the graphene production yield in most of the solvents tested in this work. Picric acid serves as a “molecular wedge” to intercalate into the edge of graphite, which plays a key role during sonication and significantly improves the production yield of graphene. The products were analyzed by microscopic techniques, including atomic force microscopy (AFM) and scanning electron microscope (SEM). The AFM images indicate that the exfoliation efficiency and amount of graphene increased by addition of picric acid in organic solvents. Moreover, the AFM images also indicate presence of bilayer graphene. SEM analysis also shows that the addition of picric acid into the organic solvent favors the exfoliation process. The produced graphene was also analyzed by XRD, FTIR, Raman and UV-visible spectroscopy. The XRD results illustrate that exfoliation was best achieved in N-methyl-2-pyrrolidone (NMP) as a solvent. FTIR and Raman results indicate that addition of picric acid has slightly defected the produced graphene surface. The amount of graphene concentration was calculated by using Beer Lambert law, and it was observed that the graphene production yield was increased by using picric acid in most of the solvents. The maximum amount of graphene concentration (0.159 mg/ml) was achieved by adding 30 mg of picric acid in NMP.

Graphene production by cracking

In recent years, graphene has found its use in numerous industrial applications due to its unique properties. While its impermeable and conductive nature can replace currently used anticorrosive toxic pigments in coating systems, due to its large strength to weight ratio, graphene can be an important component as a next-generation additive for automotive, aerospace and construction applications. The current bottlenecks in using graphene and graphene oxide and other two-dimensional materials are the availability of cost-effective, high-quality materials and their effective incorporation (functionalization and dispersion) into the product matrices. On overcoming these factors, graphene may attract significant demands in terms of volume consumption. Graphene can be produced on industrial scales and through cost-effective top-down routes such as chemical, electrochemical and/or high-pressure mechanical exfoliation. Graphene, depending on end applications, can be chemically tuned and modified via functionalization so that easy incorporation into product matrices is possible. This paper discusses different production methods and their impact on the quality of graphene produced in terms of energy input. Graphene with an average thickness below five layers was produced by both methods with varied defects. However, a higher yield of graphene with a lower number of layers was produced via the high-pressure exfoliation route. This article is part of a discussion meeting issue ‘A cracking approach to inventing new tough materials: fracture stranger than friction’.

A facile and industrial method for synthesis of modified magnetic lipophilic graphene as a super oil additive

Friction and wear are the two major reasons for energy and material losses in mechanical processes. In this research, a simple, industrial and fast exfoliation technique for the production of graphene using sodium azide and graphite in a water solvent without the need for a specific device has been presented following by lipophilizing with octylamine and only with Fe (II). Magnetic nanoparticles were applied on graphene surface, and simultaneously the graphene surface was both lipophilic and magnetic. The method used for graphene production is unique up to now and also it does not oxidize in production procedure. Performed analyzes demonstrate non-destructive properties without any changes in surface functional groups.

Preparation and Characterization of Graphene from Refined Benzene Extracted from Low-Rank Coal: Based on the CVD Technology

Industrial preparation of graphene has been a research hotspot in recent years. Finding an economical and practical carbon source and reducing the cost of production and instrument is significant in industrial graphene production. Coal is a common carbon source. Efficient improvement and utilization in the cleaning of coal has recently been a popular research area. In this study, we developed a set of graphene preparation methods based on Anhui Huainan’s low-rank gas coal (HNGC). Using self-built experimental equipment, benzene precursor was prepared from HNGC and used as carbon source to realize graphene growth. The quality of the graphene was characterized by a high-resolution microscope and Raman spectrometer. This study provides a new idea and method for the preparation of low-rank coal-based graphene.