## 4 Results and Discussion
### Analysis of the Effect of Adding N-Paraffins on the Depressant Additives Effectiveness  
Effects of n-paraffins P1 and P2 addition, on the low-temperature properties of straight-run DF F1 and F2 with depressants A1 and A2 blends, are presented in Table 4: \(\Delta\) presented in comparison with blends F1A1 and F2A1 without the addition of n-paraffins. As we can see from the data presented in Table 4 adding n-paraffins P1 to blends F1A1 and F2A1 leads to:  
* deterioration of the depressant effectiveness in relation to CP (by 2-4 \({}^{\circ}\)C for a blend F1A1 and 1-4 \({}^{\circ}\)C for the blend F2A1), no change or deterioration in the depressant effectiveness in relation to PP (by 3 \({}^{\circ}\)C for the blend F1A1 and at 0-1 \({}^{\circ}\)C for the blend F2A1);
* at concentrations of 0.10-0.50% wt.--improving the depressant effectiveness in relation to CFPP (by 1-6 \({}^{\circ}\)C for the blend F1A1 and 1-4 \({}^{\circ}\)C for the blend F2A1); at a concentration of 0.05% wt.--deterioration of the depressant effectiveness in relation to CFPP (by 2 \({}^{\circ}\)C for the blend F1A1 and 4 \({}^{\circ}\)C for the blend F2A1). \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Content of N-Paraffins, \% wt.**} & \multirow{2}{*}{**Blend**} & \multicolumn{2}{c}{**CP**} & \multicolumn{2}{c}{**CFPP**} & \multicolumn{1}{c}{**PP**} \\ \cline{3-6}  & & & & \({}^{\circ}\)**C** & \\ \hline \multirow{8}{*}{0.50} & F1A1P1 & 4\(\uparrow\) & 6\(\downarrow\) & 3\(\uparrow\) \\  & F1A2P1 & 4\(\uparrow\) & 4\(\downarrow\) & 1\(\uparrow\) \\  & F2A1P1 & 5\(\uparrow\) & 9\(\uparrow\) & 5\(\uparrow\) \\  & F2A2P1 & 3\(\uparrow\) & 4\(\downarrow\) & 6\(\uparrow\) \\  & F2A1P2 & 5\(\uparrow\) & 3\(\downarrow\) & 0 \\  & F1A2P1 & 4\(\uparrow\) & 3\(\downarrow\) & 3\(\uparrow\) \\  & F1A2P1 & 4\(\uparrow\) & 3\(\downarrow\) & 0 \\
0.25 & F2A1P1 & 4\(\uparrow\) & 5\(\uparrow\) & 5\(\uparrow\) \\  & F2A2P1 & 2\(\uparrow\) & 10\(\downarrow\) & 6\(\uparrow\) \\  & F2A1P2 & 4\(\uparrow\) & 5\(\downarrow\) & 1\(\downarrow\) \\  & F1A1P1 & 4\(\uparrow\) & 1\(\downarrow\) & 3\(\uparrow\) \\  & F1A2P1 & 3\(\uparrow\) & 1\(\downarrow\) & 0 \\
0.10 & F2A1P1 & 3\(\uparrow\) & 2\(\uparrow\) & 4\(\uparrow\) \\  & F2A2P1 & 0 & 12\(\downarrow\) & 2\(\uparrow\) \\  & F2A1P2 & 1\(\uparrow\) & 5\(\downarrow\) & 5\(\downarrow\) \\  & F1A1P1 & 2\(\uparrow\) & 2\(\uparrow\) & 3\(\uparrow\) \\  & F1A2P1 & 1\(\uparrow\) & 4\(\uparrow\) & 0 \\
0.05 & F2A1P1 & 3\(\uparrow\) & 1\(\downarrow\) & 0 \\  & F2A2P1 & 0 & 16\(\downarrow\) & 1\(\uparrow\) \\  & F2A1P2 & 1\(\uparrow\) & 7\(\downarrow\) & 5\(\downarrow\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Influence of adding n-paraffins to DF blends on the depressants effectiveness: \(\downarrow\) is decrease, \(\uparrow\) is increase. \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Number of Carbon Atoms**} & \multicolumn{2}{c}{**Content, \% wt.**} \\ \cline{2-3}  & \(\mathbf{P_{1}}\) & \(\mathbf{P_{2}}\) \\ \hline C17–C22 & 4.247 & 0.059 \\ C23 & 8.668 & 0.018 \\ C24 & 16.050 & 0.042 \\ C25 & 19.269 & 0.168 \\ C26 & 19.533 & 0.916 \\ C27 & 14.048 & 4.417 \\ C28 & 9.408 & 13.466 \\ C29 & 6.329 & 25.314 \\ C30 & 2.448 & 23.539 \\ C31 & 0.000 & 15.258 \\ C32 & 0.000 & 11.658 \\ C33–C34 & 0.000 & 5.143 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Hydrocarbon composition of P1 and P2 n-paraffins. In addition, it can be seen that with a decrease in the concentration of added n-paraffins weaken both the negative effect on the depressant effectiveness in relation to CP and PP, and the positive effect on the depressant effectiveness in relation to CFP.