Highly radiating hydrogen flames: Effect of toluene concentration and phase

Fundamental Insights into the Effect of Blending Hydrogen Flames with Sooting Biofuels

“…However, a recent experimental study on hydrogen/toluene blends with 1-5% toluene concentration (by mole of H 2 ) under turbulent non-premixed conditions revealed that increasing the additive concentration from 1 to 3% has a marked effect on soot loading, but further increases in toluene concentration are less effective [10].…”

“…Thermal radiation is typically one of the primary means of heat transfer in stationary energy systems, such as kilns and boilers, which is typically enhanced by the efficient blackbody radiation from soot particulates. Whilst gaseous species, such as CO 2 and H 2 O also contribute to thermal radiation, these tend to be minor in comparison with the radiative heat transfer from soot [10][11][12]. To enhance the thermal radiation from hydrogen flames, which have considerably lower luminosity than hydrocarbon flames, one approach is to introduce additional material with complementary properties to the flames [13].…”

“…To enhance the thermal radiation from hydrogen flames, which have considerably lower luminosity than hydrocarbon flames, one approach is to introduce additional material with complementary properties to the flames [13]. This could be in the form of non-reacting particles, or by doping the hydrogen with a small quantity of a highly sooting fuel [10,14].…”

“…To enhance the radiative heat transfer from hydrogen flames, a highly sooting hydrocarbon fuel could be chosen as a suitable additional agent [10,14]. Biofuels are preferable to hydrocarbons extracted from fossil fuels as they are derived from renewable biomass resources [15].…”

“…The concentrations of toluene and anisole are varied with a fixed H 2 /N 2 concentration to simulate the experimental cases accordingly. The velocities at the fuel and oxidant inlets are adjusted to maintain a similar momentum.To predict the soot formation and corresponding thermal radiation from the biofuelblended H 2 /N 2 flames, naphthalene (C 10 H 8 , hereafter referred to as A 2 ), is chosen for analysis in the Chemkin simulation because it is widely used in numerical studies as a key intermediate in forming large PAHs to analyse soot formation[10,52,53]. Formaldehyde (CH 2 O) is a precursor to the oxidation of the fuel and the PAH, known to be (1) abundant in the initial oxidation reactions; (2) strongly correlated to the biofuel concentration; and(3) a primary intermediate species in toluene oxidation to CO 2[10,54,55].…”