Effect of carbon-based nanoparticles on the ignition, combustion and flame characteristics of crude oil droplets

Abstract

The use of in-situ burning (ISB) as a clean-up response in the event of an oil spill has generated controversy because of unburned hydrocarbons and products of incomplete combustion left behind on an ISB site. These substances threaten marine life, both in the ocean and on the ocean floor. Treating crude oil as a multicomponent liquid fuel, this manuscript investigates the effect of carbon-based nanomaterials, acetylene black (AB) and multi-walled carbon nanotube (MWNT), on the combustion and flame characteristics of crude sourced from the Bakken formation (ND, USA). Sub-millimeter droplets of colloidal suspensions of Bakken crude and nanomaterials at various particle loadings were burned, and the process was captured with CMOS and CCD cameras. The resulting images were post-processed to generate burning rate, ignition delay, total combustion time, and flame stand-off (FSR) ratio data for the various crude suspensions. A maximum combustion rate enhancement of 39.5% and 31.1% was observed at a particle loading of 0.5% w/w acetylene black nanoparticles and 0.5% w/w multi-walled carbon nanotubes, respectively. Generally, FSR for pure Bakken was noted as larger than for Bakken with nanoparticle additives. These results are expected to spur further investigations into the use of nanomaterials for ISB crude oil clean-ups.

Graphene oxide doped ethanol droplet combustion: Ignition delay and contribution of atomization to burning rate

“…As can be seen, the effects of these two competing mechanisms droplet equivalent diameter cancel out, leading to a nearly constant of the droplet equivalent during 0. This observation is expected and is consistent with the results in literature for pure ethanol [57], α-methylnaphthalene [102], and Bakken crude oil [10].…”

“…The maximum increase of the ignition delay for the loading concentration of 0.1% are 20.9, 16.8, and 16.6% pertaining to ethanol droplets doped with pGO, rGO, and hGO, respectively. The increase in the ignition delay of liquid fuels doped with carbonaceous nanomaterials is consistent with the observations reported in [9,10,13]. It is speculated that, generally, the presence of the carbonaceous nanomaterials increases the absorption of the heat generated by the flame without an immediate increase in the droplet temperature.…”

“…It can be inferred from the results presented in [50][51][52]61] that increasing the concentration of the doping agent as well as reducing the oxygen content of the graphene oxide increase the thermal conductivity of the fuel. It is speculated that the enhancement of K 1 with addition of graphene oxide is due to a potential increase of the thermal conductivity, which is similar to the conclusions reported in [3,9,10,12].…”

“…Although several studies reported the occurrence of atomization, see for example [2,6,9,10], our quantitative understanding related to the characteristics of this phenomenon is limited and requires further investigations. For example, trajectory and velocity of the ejected baby droplets as a result of atomization, as well as how such phenomenon influences the droplet burning rate is of interest.…”

The Effects of Nano-Additives Added to Diesel-Biodiesel Fuel Blends on Combustion and Emission Characteristics of Diesel Engine: A Review

“…Hao et al [53] found that aluminium (Al) nano-additives had a strong oxygen extraction ability and could significantly reduce the induction time and energy required for catalytic exothermic reactions. Singh et al [54] found that carbon-based single-walled nanotubes and multi-walled nanotubes could dramatically increase the ignition rate, ignition delay period, and extend the total combustion time. Therefore, it can be concluded that nano additives are very promising in fuels.…”