Characterization of the Ultrafine and Black Carbon Emissions from Different Aviation Alternative Fuels

Assessment of the Fuel Composition Impact on Black Carbon Mass, Particle Number Size Distributions, Solid Particle Number, Organic Materials, and Regulated Gaseous Emissions from a Light-Duty Gasoline Direct Injection Truck and Passenger Car

“…Similar to the PMI, fuels containing a higher aromatic content have higher TSI values as these compounds generate more BC during combustion when compared to aliphatic hydrocarbons. The higher emission rates of particles could lead to more coagulation resulting in particles with larger diameters, consistent with the particle number size distributions observed with high fuel aromatic content. − One study suggested that operating an engine at the same conditions with fuels containing nearly identical fuel aromatic content but substituting the monoaromatics with naphthalenes (from 0.78% to 1.19% by volume) could increase BC and nonvolatile PM emissions by 40% and 30%, respectively . Multiple NASA studies also suggest that the fuel sulfur and aromatic content affects the volatile PM emissions and contribute to measurement variability.…”

“…Early observations showed that different hydrocarbons have different tendencies to generate BC. − Many studies often compared petroleum-based jet fuel to renewable jet fuel containing significantly less or even the absence of aromatic hydrocarbons. Observations suggested that low fuel aromatic content, high hydrogen to carbon ratio, and low iso-to-normal paraffin ratio are factors to explain the lowered particulate matter mass (PMM) emissions from aviation turbine engines. − Some studies reported that particle size distributions could shift to larger diameter with increasing fuel aromatic content and thus produce higher BC emissions. − These studies have implied the possible existence of relationships between BC formation and fuel composition.…”

Review of black carbon emission factors from different anthropogenic sources

“…Chan et al (2013) found that the C-HEFA blend reduced BC emissions by 50% at idle and 32% at take-off when compared to F34. In the study by Chan et al (2015) the use of 50% HEFA-SPK led to significant reduction in BC mass emissions compared to Jet A-1 by 58%-85% for various engine load conditions. For the 100% FT-SPK fuel, reductions of BC emissions compared to Jet A-1 emissions of 70%-97% were achieved.…”

“…Typically, the BC EFs follow a U-shaped curve, having high emissions at idle conditions, and again at high thrust percentages, corresponding to engine operation during cruising, climbout and take-off. Cruise corresponds to 80% thrust (Chan et al 2015), whereas climb-out requires 85% (Durdina et al 2017, Kinsey et al 2019, and take-off 95%-100% of the nominal engine thrust (Chan et al 2015, Durdina et al 2017, Kinsey et al 2019. Durdina et al (2017) found that for a 1 h flight, over 70% of the BC emissions came from the climb phase and over 25% dispersed under 3000 ft altitude.…”

“…JP-8 (the US military) and F34 (NATO) are military jet fuels, similar to commercial aviation's Jet A-1, but with the addition of corrosion inhibitor and anti-icing additives (Chevron 2007). The alternative fuels in the studies include synthetic FT kerosene produced from natural gas (FT (NG), Kinsey et al 2019), synthetic paraffinic kerosene (SPK) produced from coal (FT (coal), Kinsey et al 2019), and fully synthetic FT SPK (Chan et al 2015). The studies also reported BC EFs for three renewable fuels; (a) fully synthetic kerosene with aromatics (CH-SKA, Chan et al 2015) from industrial oilseeds carinata (Brassica carinata) produced through catalytic hydrothermolysis process, (b) 50% volume mixed hydro-processed esters and fatty acid (HEFA) paraffinic kerosene produced from camelina (Camelina sativa L.) oilseeds through a hydro-treating and cracking process, mixed with 50% Jet A-1 (HEFA-SPK, Chan et al 2015), and (c) camelina-based hydro-processed bio-jetfuel by 50% in volume mixed with F34 (C-HEFA, Chan et al 2013).…”