# Assessment of Carbon Emissions at the Logistics and Transportation Stage of Prefabricated Buildings
## 2 Research Boundary and Key Parameters
### Selection of Carbon Emission Factors
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Transportation Mode**} & \multirow{2}{*}{**Type of Transportation Vehicle**} & \multirow{2}{*}{**Rated Load Capacity (t)**} & \multirow{2}{*}{**Fuel Type**} & \multicolumn{2}{c}{**Carbon Emission Factor**} \\  & & & & **[kgCO\({}_{2g}\)/(t\(\cdot\)km)]** \\ \hline \multirow{6}{*}{Road} & Light truck & 2 t & Gasoline & 0.334 \\  & Light truck & 2 t & Diesel & 0.286 \\ \cline{2-5}  & \multirow{2}{*}{Medium-sized truck} & 8 t & Gasoline & 0.115 \\ \cline{2-5}  & & 8 t & Diesel & 0.179 \\ \cline{2-5}  & & 10 t & Gasoline & 0.104 \\ \cline{2-5}  & & 18 t & Gasoline & 0.104 \\ \cline{2-5}  & Heavy truck & 10 t & Diesel & 0.162 \\ \cline{2-5}  & & 18 t & Diesel & 0.129 \\ \cline{2-5}  & & 30 t & Diesel & 0.078 \\ \cline{2-5}  & & 46 t & Diesel & 0.057 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Summary of carbon emission factors for each type of transportation. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Type**} & \multirow{2}{*}{\begin{tabular}{c} **Energy** \\ **Source** \\ **Name** \\ **(KJ/kg)** \\ \end{tabular} } & \begin{tabular}{c} **Average** \\ **Low-Level Heat** \\ **Generation** \\ **(KJ/kg)** \\ \end{tabular} & \begin{tabular}{c} **Discounted** \\ **Standard Coal** \\ **(kgce/kg)** \\ \end{tabular} & \begin{tabular}{c} **Unit Calorific** \\ **Value Carbon** \\ **Content** \\ **(kgce/kg)** \\ \end{tabular} & \begin{tabular}{c} **Carbon** \\ **Value Carbon** \\ **Content** \\ **(tC/T)** \\ \end{tabular} & \begin{tabular}{c} **Emission** \\ **Factor** \\ **Rate (\%)** \\ \end{tabular} & \begin{tabular}{c} **Emission** \\ **Factor** \\ **(tCO\({}_{2}\)/T)** \\ \end{tabular} & \
\begin{tabular}{c} **Emission** \\ **Factor** \\ **(kgCO\({}_{2}\)/kg)** \\ \end{tabular} &
\begin{tabular}{c} **Emission** \\ **Factor** \\ **(kgCO\({}_{2}\)/kg)** \\ \end{tabular} \\ \hline \multirow{6}{*}{**Solids**} & Anthracite & 20,908 & 0.7143 & 27.4 & 0.94 & 94.44 & 1.97 & 2.76 \\  & Bituminous & 20,908 & 0.7143 & 26.1 & 0.93 & 89.00 & 1.86 & 2.61 \\  & Coal & 20,908 & 0.7143 & 28.0 & 0.96 & 98.56 & 2.06 & 2.88 \\  & Lignite & 28,435 & 0.9714 & 29.5 & 0.93 & 100.60 & 2.86 & 2.94 \\  & Type coal & 20,908 & 0.7143 & 33.6 & 0.90 & 110.88 & 2.32 & 3.25 \\ \hline \multirow{6}{*}{**Liquids**} & Crude oil & 41,816 & 1.4286 & 20.1 & 0.98 & 72.23 & 3.02 & 2.11 \\  & Gasoline & 43,070 & 1.4714 & 18.9 & 0.98 & 67.91 & 2.93 & 1.99 \\  & Diesel & 42,652 & 1.4571 & 20.2 & 0.98 & 72.59 & 3.10 & 2.12 \\  & Fuel oil & 41,816 & 1.4286 & 21.1 & 0.98 & 75.82 & 3.17 & 2.22 \\  & Kerosene & 43,070 & 1.4714 & 19.6 & 0.98 & 70.43 & 3.03 & 2.06 \\  & Liquefied & 50,179 & 1.7143 & 17.2 & 0.98 & 61.81 & 3.10 & 1.81 \\  & LPG & 38,931 & 1.3300 & 15.3 & 0.99 & 55.54 & 2.16 & 1.63 \\ \hline \hline
**Gas** & Natural gas & 38,931 & 1.3300 & 15.3 & 0.99 & 55.54 & 2.16 & 1.63 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of CO\({}_{2}\) emission factors for various fossil fuels. \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Region**} & \multicolumn{2}{c}{**Carbon Emission Factor**} & \multirow{2}{*}{**Region**} & \multicolumn{2}{c}{**Carbon Emission Factor**} \\  & & **(kgCO\({}_{2}\)/kWh)** & & **(kgCO\({}_{2}\)/kWh)** \\ \hline East China Power Grid & 1.04 & Central China Power Grid & 0.848 \\ \hline North China Power Grid & 1.27 & Northwest China Power Grid & 0.944 \\ \hline Northeast Power Grid & 1.36 & Southern Power Grid & 0.854 \\ \hline National average & & 1.05 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Summary of carbon emission factors of electric energy. formula, based on the above-mentioned carbon emission factors, to reflect the real carbon emissions of the logistics and transportation stages relatively accurately. \[E_{t}=E_{tp}+E_{tu} \tag{5}\]  
\(E_{t}\): Total carbon emissions during the logistics stage. \(E_{tp}\): Carbon emissions from the logistics phase of prefabricated components. \(E_{tu}\): Carbon emissions from the logistics phase of building materials.