Discussion

Table 4.1 provides information on the primary and secondary research fronts for both biodiesel fuels and petrodiesel fuels. It also provides information on the distribution of these research fronts in the article papers for nanotechnology application on diesel fuels, the 100-most-cited papers, and over 121,000 population papers in the broader fields of petrodiesel and biodiesel fuels.

As this table shows, the research fronts of ‘biodiesel fuels in general’, ‘feedstockbased biodiesel fuels’, and ‘petrodiesel fuels’ comprise 28, 24, and 48% of these papers, respectively, in this field.

TABLE 4.1

Research Fronts

• *Sample size: 25.
• **Sample size: 100.
• ***Sample size: 121,000.

In the first group of article papers, those on ‘biooils’, ‘biodiesel fuels in general’, and 'glycerol' comprise 4, 8, and 16% of these papers, respectively. In the second group of article papers, ‘edible oil-based biodiesel fuels’, ‘nonedible oil-based biodiesel fuels’, ‘waste oil-based biodiesel fuels’, and ‘algal oil-based biodiesel fuels’ comprise 16, 4, 4, and 0% of these papers, respectively. In the final group of article papers, ‘crude oils’, ‘petrodiesel fuels in general’, ‘emissions from petrodiesel fuels’, and the ‘health impact of the emissions from petrodiesel fuels’ comprise 40, 8, 0, and 0% of these papers, respectively.

The data show that the most-prolific research front has concerned the applications of nanotechnology to ‘crude oils’, including ‘crude oil recovery’, ‘remediation of crude oils in the environment’, and ‘water-in-oil emulsions’. The applications of nanotechnology in ‘glycerol applications’ and ‘edible oil-based biodiesel fuels’ have also been prolific.

It is notable that there have been no prolific papers in the fields of ‘biooil upgrading’, ‘biodiesel emissions’, ‘algal biodiesel fuels’, ‘crude oil properties’, ‘crude oil refining’, ‘petrodiesel desulfurization’, ‘power generation by petrodiesel fuels’, ‘petrodiesel fuel emissions’, and the ‘health impact of petrodiesel emissions’.

These prolific studies on nanotechnology applications in the fields of biooils, biodiesel fuels, crude oils, and petrodiesel fuels, presented in this chapter, highlight the importance of nanotechnology in these fields. These studies also show the importance of nanomaterials as the nanocatalyts in these fields, ranging from ‘crude oil recovery’ and ‘remediation of crude oils in the environment’ to ‘biooil production’, ‘biodiesel production’, and the production of biochemical and bioenergy from glycerol, a by-product of biodiesel fuels.

Biooils

Iliopoulou et al. (2007) test two mesoporous aluminosilicate Al-MCM-41 materials (Si/Al=30 or 50) as catalysts for the in situ upgrading of biomass pyrolysis vapors in comparison to a siliceous MCM-41 sample and to a non-catalytic biomass pyrolysis in a paper with 167 citations. They conclude that these mesoporous materials were instrumental in biooil production.

Biodiesel Fuels

Production

Liu et al. (2008) study the development of sulfonated ‘ordered mesoporous carbon’ for the catalytic preparation of biodiesel in a paper with 149 citations. They conclude that these mesoporous catalysts were instrumental in biodiesel production.

Properties

Sajith et al. (2010) study the impact of the addition of cerium oxide in nanoparticle form on the major physicochemical properties and the performance of biodiesel in a paper with 194 citations. They conclude that such an addition of cerium oxide nanoparticles was instrumental in enhancing the major physicochemical properties and the performance of biodiesel.

Glycerol

Huang et al. (2008) prepare highly dispersed copper nanoparticles supported on silica by a simple and convenient precipitation-gel technique, and compare their physicochemical properties and activity to those of a catalyst prepared by the conventional impregnation method for glycerol hydrogenolysis in a paper with 254 citations. They conclude that these nanoparticles were efficient and stable catalysts for glycerol hydrogenolysis. Simoes et al. (2010) study the electrooxidation of glycerol on Pd-based nanocatalysts for application in alkaline fuel cells for chemicals and energy cogeneration in a paper with 219 citations. They conclude that Pd-based nanocatalysts were instrumental for the electrooxidation of glycerol.

Hong et al. (2015) study bimetallic PdPt nanowire networks with enhanced electrocatalytic activity for ethylene glycol and glycerol oxidation in a paper with 161 citations. They conclude that these catalysts were instrumental in the efficient production of these biodiesel fuels. Clacens et al. (2002) study the selective etherification of glycerol to poly glycerols over impregnated basic MCM-41 type mesoporous catalysts in a paper with 154 citations. They conclude that these mesoporous catalysts were instrumental in the selective etherification of glycerol to polyglycerols.

Edible Oil-based Biodiesel Fuels

Reddy et al. (2006) develop a route for the production of biodiesel via the transesterification of soybean oil (SBO) and poultry fat with methanol in quantitative conversions at room temperature using nanocrystalline calcium oxides as catalysts in a paper with 230 citations. They conclude that these nanocrystalline calcium oxides were instrumental in biodiesel production. Verziu et al. (2008) study the catalytic activity for the production of sunflower and rapeseed oil-based biodiesel with three morphologically different nanocrystalline MgO materials prepared using simple, green, and reproducible methods in a paper with 161 citations. They conclude that these catalysts were instrumental in the efficient production of these biodiesel fuels.

Wang and Yang (2007) study the transesterification reaction of soybean oil with supercritical/subcritical methanol by Nano-MgO catalysts in a paper with 157 citations. They conclude that these catalysts were instrumental in the efficient production of these biodiesel fuels. Carmo et al. (2009) study the production of biodiesel by esterification of palmitic acid over mesoporous aluminosilicate Al-MCM-41 in a paper with 145 citations. They conclude that these nanocatalysts were instrumental in biodiesel production from palmitic acids.

Nonedible Oil-based Biodiesel Fuels

Deng et al. (2011 ) study the production of biodiesel from Jatropha oil catalyzed by a nanosized solid basic catalyst in a paper with 171 citations. They conclude that these nanocatalyts were instrumental for biodiesel production from Jatropha oils.

Waste Oil-based Biodiesel Fuels

Reddy et al. (2006) develop a route for the production of biodiesel via transesterification of soybean oil and poultry fat with methanol in quantitative conversions at room temperature using nanocrystalline calcium oxides as catalysts in a paper with 230 citations. They conclude that these nanocrystalline calcium oxides were instrumental in biodiesel production.

Crude Oils

Water-in-Oil Emulsions

Si et al. (2015) report a strategy to create ‘fibrous, isotropically bonded elastic reconstructed’ aerogels with a hierarchical cellular structure and super-elasticity by combining electrospun nanofibers and the freeze-shaping technique for separating surfactant-stabilized water-in-oil emulsions in a paper with 333 citations. They conclude that these aerogels were instrumental in the effective separation of oil/water emulsions. Arriagada and Osseo-Asare (1999) study the effect of an ammonia concentration on the region of existence of single-phase water-in-oil microemulsions for the system ‘polyoxyethylene (5) nonylphenyl ether (NP-5)/cyclohexane/ammonium hydroxide’ in a paper with 326 citations. They conclude that the effect of an ammonia concentration on the region of existence of single-phase water-in-oil microemulsions for this system was significant.

Oil Recovery

Suleimanov et al. (2011) study the nanofluids for enhanced oil recovery (EOR) in a paper with 151 citations. They use an aqueous solution of anionic surface-active agents with the addition of light non-ferrous metal nanoparticles. They conclude that the use of a developed nano-suspension results in a considerably increased EOR. Zhang et al. (2014) study the EOR using nanoparticle dispersions in a paper with 149 citations. They conclude that using nanoparticle dispersions was instrumental for EOR. Hendraningrat et al. (2013) study nanofluid enhanced oil recovery in a paper with 143 citations focusing on the parameters involved in the structural disjoining pressure mechanism, such as lowering interfacial tensions (IFTs) and altering wettability. They conclude that application of nanofluid EOR was an alternative EOR method.

Remediation of Crude Oils

Calcagnile et al. (2012) present a novel composite material based on commercially available polyurethane foams functionalized with colloidal ‘superparamagnetic iron oxide nanoparticles’ and submicrometer polytetrafluoroethylene particles, which can efficiently separate oil contaminants from water in a paper with 417 citations. They conclude that by simply moving them around oil-polluted waters using a magnet, they could absorb the floating oil from polluted regions, thereby purifying the water underneath. This low-cost process could easily be scaled up to clean large-area oil spills in water. Toyoda and Inagaki (2000) study the sorption behaviors of four kinds of heavy oils into exfoliated graphites with different bulk densities in a paper with 270 citations. They conclude that exfoliated graphite with a low bulk density was a promising material for the sorption and recovery of spilled heavy oil.

Yang et al. (2011) show that fluorous ‘metal-organic frameworks’ are highly hydrophobic porous materials with a high capacity and affinity to C₆-C_s hydrocarbons of oil components in a paper with 240 citations. They conclude that there is great promise for FMOFs in applications such as the removal of organic pollutants from oil spills or ambient humid air, hydrocarbon storage and transportation, and water purification, under practical working conditions. Ge et al. (2017) report on a Joule-heated ‘graphene-wrapped sponge’ to clean up viscous crude oil at a high sorption speed in a paper with 184 citations. They conclude that this in situ Joule self-heated sorbent design would promote the practical application of hydrophobic and oleophilic oil sorbents in the clean-up of viscous crude-oil spills. Lin et al. (2012) report on nano-porous polystyrene fibers prepared via a one-step electrospinning process used as oil sorbents for oil spill cleanup in a paper 155 citations. They conclude that these nano-porous materials have great potential for use in wastewater treatment, oil accident remediation, and environmental protection.

Petrodiesel Fuels

Production

Kang et al. (2009) study ruthenium nanoparticles supported on carbon nanotubes as efficient catalysts for the selective conversion of synthesis gas to diesel fuel in a paper with 190 citations. They conclude that these catalysts were instrumental in biodiesel production.

Properties

Tyagi et al. (2008) improve the ignition properties of diesel fuels by investigating the influence of adding aluminum and aluminum oxide nanoparticles to diesel in a paper with 161 citations. They conclude that the addition of these nanoparticles enhanced the ignition properties of petrodiesel fuels.