## 4 Engine Test Results
### Other Models of New Biodiesels  
To study the effects of different biodiesel ether groups on engine combustion and emissions, different ether groups were selected and transesterified to biofatty acids, therefore, several kinds of biodiesel were prepared. Here listed are Ethylene Glycol Monoethyl Ether Soyate and Palm Oil Monoester, Ethylene Glycol propyl Ether Palm Oil Monoester, propylene glycol methyl ether palm oil monoester, diethylene glycol ethyl ether and triethylene glycol ethyl ether cottonseed oil Monoester were synthesized respectively. Their effects on engine combustion and emissions were digested below. \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Fuel Type** & **Engine** & **Operation Condition** & **Smoke** & **HC** & **CO** & **NO\({}_{\mathrm{x}}\)** \\ \hline FAME & 2102 QB & \begin{tabular}{c} 1400 r-min\({}^{-1}\) \\ 2200 r-min\({}^{-1}\) \\ \end{tabular} & 47.4\% & 36.4\% & 62.5\% & 16.2\% \\ \hline EGMEROM & TY110 & 2200 r-min\({}^{-1}\) & 78.2\% & 61.5\% & 50.0\% & Increase slightly \\ \hline EGMESOM & TY110 & 2200 r-min\({}^{-1}\) & 74.6\% & 61.6\% & 79.1\% & changeless \\ \hline EGMEPOM (Peanut) & TY110 & \begin{tabular}{c} 1400 r-min\({}^{-1}\) \\ 2000 r-min\({}^{-1}\) \\ \end{tabular} & 75.0\% & 69.2\% & 50.0\% & changeless \\ \hline EGMEPOM (Palm) & 2102 QB & \begin{tabular}{c} 1400 r-min\({}^{-1}\) \\ 2000 r-min\({}^{-1}\) \\ \end{tabular} & 58.3\% & 66.7\% & 60.0\% & changeless \\ \hline EGMECOM & 2102 QB & \
\begin{tabular}{c} 1400 r-min\({}^{-1}\) \\ 2000 r-min\({}^{-1}\) \\ \end{tabular} & 55.6\% & 66.7\% & 54.5\% & 32.2\% \\ \hline EGMECOM & 2102 QB &
\begin{tabular}{c} 1400 r-min\({}^{-1}\) \\ 2000 r-min\({}^{-1}\) \\ \end{tabular} & 50.0\% & 55.6\% & A little & 39.3\% \\ \hline \end{tabular}
\end{table} 
Table 3: Effect of biodiesel on the reduction of engine emissions [32; 33; 34; 38; 39; 40; 41; 42]. 1. Ethylene glycol ethyl ether Soyate oil monoester  
Compared with petrodiesel operation, when ran on pure biodiesel or their mixture, the engine power output remained the same level, while fuel consumption increased to some extent. This was thought to be unit heat energy remained due to the same product of decrease of LHV and increase of density. When pure biodiesel operating, engine smoke reduced by 59.8-83.3%, CO reduction rate was 47.7-76.7% and HC decreased by 48.9-64.7%, while NO\({}_{\rm x}\) increased little. When 50% blending operation, engine exhaust smoke reduced 37.5-75%, CO reduced 13.9-55.8%, HC reduced 30.3-45.7%. NO\({}_{\rm x}\) reduced 50%. 2. Ethylene glycol ethyl ether palm oil monoester  
The cylinder pressure analysis indicated that, the peak pressure reduced about 7% as well as the calculated heat release rate, while the ignition delay advanced 2.5 deg. CA. And engine brake thermal efficiency was improved for the fast combustion processes within the cylinder. When diesel engine is fueled with this palm oil monoester, exhaust smoke reduced 36.5% to 60.0% when pure operation and 10% to 25% when the engine ran on the mixture of 25% blending with petrodiesel. Engine speed had a little effect on it. B100 made CO emission reduce 25% to 66%, HC reduce 44.4% to 55.6%, NO\({}_{\rm x}\) reduce 17% to 32.2% according to the engine load and speed, respectively. 3. Ethylene Glycol n-Propyl Ether Palm Oil Monoester [45]. With an increase of EGFPOM in the blends, the peak cylinder pressure decreased while the start of combustion advanced. Meanwhile, the BSFC and brake thermal efficiency increased because of the low LHV and high oxygen content. Smoke reduction was not significant when B25 operating, while B100 fueled operation, smoke reduced by 50% approximately. CO reduced 33.2% for B25 and 66.6% for B100. HC were 11% for B25 and 27.1% for B100. NO\({}_{\rm x}\) were reduced by 15.8% to 23.7% for B25 and B100 operating conditions. 4. Propylene glycol methyl ether palm oil monoester [44]. For the tested engine working under partial load mode, smoke emissions generally can be lessened by more than 50% and up to 75.0%. CO emissions can be reduced by 16.7% to 76.2%.