## 2 Aviation Fuel Emissions
### Aviation PM Emissions
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Ref.** & **Fuel** & **Aromatics** & **Method/Burning Platform** & **PM Emissions** \\ \hline \multirow{4}{*}{ASTM D7566 [10]} & FT-SPK & \textless{}0.5 m\% & \multirow{4}{*}{D2425} & \multirow{4}{*}{-} \\  & HEFA-SPK & \textless{}0.5 m\% & & \\  & SIP & \textless{}0.5 m\% & & \\  & FT-SPK/A & \textless{}0.5 m\% & & \\  & AT-SPK & \textless{}0.5 m\% & & \\  & CHI & 8.4-21.2 m\% & & \\  & HC-HEFA SPK & \textless{}0.5 m\% & & D2425 & \\ \hline ASTM D1655 [11] & Jet A or Jet A-1 & \textless{}25/26.5\% & & D1319, etc. & - \\ \hline \multirow{4}{*}{[PERSON] et al. (2021) [116]} & Jet A & 18.1 \% & \multirow{4}{*}{CRG56-7B26 engine} & \multirow{4}{*}{\begin{tabular}{c} nvPM number decreased by 60\% and 10\% during ground idle and take-off phases, respectively. nvPM mass and nvPM number decreased by 20\% and 25\% over a standardized ITO cycle, respectively.} \\ \cline{1-1}  & Jet A-1 & 15.6 \% \\ (2019) [78] & Readijet & 20.9 \% & \\  & AT\(\textless{}\)1 \% & & \\ \hline \multirow{2}{*}{[PERSON] et al. (2021) [118]} & Jet A-1 & 17.3 \% & \multirow{2}{*}{GTM-120 engine} & \multirow{2}{*}{\begin{tabular}{c} Total particle number and mass by approximately \\ 18\% and 53\%, respectively \\ \end{tabular} } \\  & 50\% AJ-SPK blend & 8.8 \% & \\ \hline \multirow{4}{*}{[PERSON] et al. (2016) [119]} & Jet A-1 & 18.3 \% & \multirow{4}{*}{\begin{tabular}{c} GE CF-700-2D-2 turbofan \\ engine \\ \end{tabular} } & \multirow{4}{*}{\begin{tabular}{c} 100\% CH-SKA, 50\% HEFA-SPK, and 100\% FF-SPK respectively \\ reduce EI-PM by 7-25\%, 40-60\%, and 70-95\%. \\ \end{tabular} } \\  & FT-SPK & 10.4 \% & & \\ \hline \multirow{4}{*}{[PERSON] et al. (2020) [103]} & Jet A-1 & 18.5 \% & \multirow{4}{*}{\begin{tabular}{c} GE CF/700-2D2 Engine \\ 97\% compared with Jet A-1 \\ \end{tabular} } \\  & JT-SPK blend & 8.8 \% & & \\  & AT-SPK Naet & 0 \% & & \\ \hline \multirow{4}{*}{[PERSON] et al. (2021) [121]} & Jet A-1 & 18.8/172 /18.6/ & \multirow{4}{*}{\begin{tabular}{c} Airbus \\ A320 equipped with two \\ V2527-A5 engines \\ \end{tabular} } & \multirow{4}{*}{Semisynthetic jet fuels lead to a 50\% to 70\% reduction in both soot and ice number concentrations} \\  & & & \\  & 30\% HEFA-SPK & 9.5 \% & & \\  & blend & & \\ \hline \multirow{4}{*}{[PERSON] et al. (2015) [122]} & Jet A-1 & 15.5 \% & \multirow{4}{*}{\begin{tabular}{c} Garnett GTCP85 \\ (APU) \\ \end{tabular} } & \multirow{4}{*}{\begin{tabular}{c} 50\% UCO-HEFA blend fuel reduced nvPM number and mass \\ emissions by approximately 35\% and 60\%, respectively. \\ \end{tabular} } \\  & UCO-HEFA & 1.91 \% & & \\ \hline \multirow{4}{*}{[PERSON] et al. (2017) [123]} & Medium-sulfur- & \multirow{4}{*}{\
\begin{tabular}{c} DC-8 aircraft equipped with \\ four C7B6-2C1 \\ engines \\ \end{tabular} } & \multirow{4}{*}{
\begin{tabular}{c} Compared with medium-sulfur-content Jet A fuel, the 50\% HEFA \\ blend fuel reduced the number of vPM and nvPM by 52\% and \\ 45\%, respectively, while decreasing vPM volume, nvPM volume, nvPM volume, \\ and total PM volume by approximately 50\%. \\ \end{tabular} } \\  & Low-sulfur-content Jet A fuel & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Information regarding the investigated SAF and fuels and the burning platforms and decline situation for PM emissions in literature. Figure 5: EI ratio compared with medium-sulfur-content Jet A fuel under medium thrust at cruise conditions (PM = particulate matter, vPM = volatile particulate matter, nvPM = non-volatile particulate matter) [123]. The 50% HEFA blend fuel effectively reduced both the number and volume of vPM and nvPM. Additionally, blend fuel exhibited varying degrees of reductions in BC, CO and NOx emissions.