## 3 Results and Discussion
### Hydrocracking Experiments
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Analysis** & \begin{tabular}{c} **Diesel Fraction** \\ **HC Product** \\ **WHSV.0.5 h\({}^{-1}\)** \\ \end{tabular} & \
\begin{tabular}{c} **Diesel Fraction** \\ **HC Product** \\ **WHSV.1.0 h\({}^{-1}\)** \\ \end{tabular} &
\begin{tabular}{c} **Diesel Fuel Standards EN590** \\ **Min.** \\ \end{tabular} \\ \hline Density at 15 \({}^{\circ}\)C, kg/m\({}^{3}\) & 799.3 & 811.5 & 820 & 820 \\ \hline Kinematic viscosity at 40 \({}^{\circ}\)C, mm\({}^{2}\)/s & 2.77 & 3.38 & 2.0 & 2.0 \\ \hline Sulphur content, mg/kg & 2.5 & 38.1 & N/A & N/A \\ \hline Nitrogen content, mg/kg & 1.02 & 2.69 & N/A & N/A \\ \hline Elemental analysis, wt.\% & & & & \\ \hline Carbon content & 85.6 & 86.5 & N/A & N/A \\ \hline Hydrogen content & 14.5 & 13.4 & N/A & N/A \\ \hline Distillation & & & & \\ \hline -Evaporates at 250 \({}^{\circ}\)C: & 30 & 20 & N/A & 65 \\ \hline Evaporates at 350 \({}^{\circ}\)C: & 100 & 90 & 85 & N/A \\ \hline
95\% evaporated at: & 337.3 & 356.2 & N/A & 360 \\ \hline Cetane index & 70 & 68 & 46 & N/A \\ \hline Cetane number & 68 & 67 & 51 & N/A \\ \hline Flash point, \({}^{\circ}\)C & 88 & 93 & 55 & N/A \\ \hline Refractive index & 1.4431 & 1.4498 & N/A & N/A \\ \hline Water content, wt.\% & \textless{}0.01 & \textless{}0.01 & N/A & 0.02 \\ \hline Impurities, mg/kg & 2.04 & 4.18 & N/A & 24 \\ \hline Oxidative stabilisation, h & \textgreater{}48 & \textgreater{}48 & 20 & N/A \\ \hline Colour ASTM D 1500 & 0.3 & 0.5 & N/A & 2.0 \\ \hline CPFF & \textasci{}20 & \textasci{}1 & N/A & \textasci{}1 \\ \hline n-d m method, wt.\% & & & & \\ \hline Aromatic Carbon & 4.6 & 6.6 & N/A & N/A \\ \hline Naphthenic Carbon & 25.5 & 22.4 & N/A & N/A \\ \hline Paraffinic Carbon & 55.5 & 57.5 & N/A & N/A \\ \hline Mono-aromatics & 7.7 & 12.3 & N/A & N/A \\ \hline Di-aromatics & 1.0 & 1.7 & N/A & N/A \\ \hline Poly-aromatics & 0.2 & 0.4 & N/A & 8.0 \\ \hline Total aromatics & 8.9 & 14.4 & N/A & N/A \\ \hline GCxGC-MS analysis, \% & & & & \\ \hline n-alkanes & 13.29 & 17.71 & N/A & N/A \\ \hline i-alkanes & 66.17 & 63.98 & N/A & N/A \\ \hline Alkenes + cycloalkanes & 16.03 & 12.22 & N/A & N/A \\ \hline Aromatics & 3.28 & 4.86 & N/A & N/A \\ \hline Undefined compounds & 1.24 & 1.24 & N/A & N/A \\ \hline \hline \end{tabular}  
* Summer diesel (max. 0 \({}^{\circ}\)C), transition diesel (max. \(-10\)\({}^{\circ}\)C), winter diesel (max. \(-20\)\({}^{\circ}\)C).  
\end{table} 
Table 4: Detailed characterisation of the diesel fraction from the product of the VGG-H-FTS co-processing at different WHSV (operating conditions: T = 420 \({}^{\circ}\)C, WHSV = 0.5–1.0 h\({}^{-1}\), P = 10.0 MPa). indicates a higher hydrogenation ratio of the feedstock. This result was also confirmed by the presence of naphthenes and a high content of isomers and cycloalkanes, which might be due to aromatic compound hydrogenation. The only exception to these promising results is the product density, which is lower than what is required by EN590. This fact was due to the different density of linear paraffin regarding the VGO compounds. However, this point might not be a significant issue and is easily solved by additive addition or fuel blending.