Methanol gasoline blends are a more economical, and environmentally friendly fuels than gasoline alone, and are widely used in the transportation industry. The content of methanol in methanol gasoline plays an important role in ensuring the quality of gasoline. In some solutions, due to the shortage of energy and illegal profits, the problem of gasoline adulteration and its fineness, has received more and more attention, which would seriously affect the operating condition and service life of internal combustion engines. Therefore, it is very important to identify the correct level of gasoline. However, the traditional detection method is complex and time-consuming. To this end, the feasibility of using attenuated total reflectance Fourier transform infrared (ATR-FTIR) methods coupled with chemometrics methods were investigated to quantitatively and qualitatively analyze methanol gasoline. The qualitative analysis result of partial least squares discriminant analysis (PLS-DA) obtained 100% and 98.66% accuracy in the calibration set and the prediction set, respectively. As for quantitative analysis; two regression algorithms of partial least squares regression (PLSR) and the least square support vector machine (LS-SVM), as well as two variables selection methods of the successive projections algorithm (UVE) competitive adaptive reweighted sampling (CARS) and uninformative variable elimination (UVE) were combined to establish the quantitative model. By comparing the performance of the optimal models; the UVE-PLSR model performed best with a residual predictive deviation (RPD) value of 6.420. The qualitative and quantitative analysis results demonstrate the feasibility of using ATR-FTIR spectra to detect the methanol in methanol gasoline. It is believed that the promising IR spectra will be widely used in gasoline energy quality control in the further.

By adding an injection system of n-butanol on the intake manifold, the four-cylinder direct injection (DI) diesel engine had been modified to operate in n-butanol/diesel compound combustion mode (BDCC). Effects of temperature, combustion, and emissions were experimentally investigated on this experimental engine. The temperature, combustion, and emissions characteristics were compared between the original neat diesel mode and the BDCC mode. The engine speeds were set to be 2,250, 2,800, and 3,350 rpm, and the engine loads were set to be 25, 50, 75, and 100%, respectively. The experimental results demonstrated that the intake temperature, the combustion temperature, and the exhaust temperature were decreased under BDCC mode, compared with that of the original neat diesel mode. The form of heat release rate was significantly changed using the BDCC mode, and the maximum combustion pressure of BDCC mode was higher than that of diesel mode. Under the low load, the ignition delay of BDCC mode was longer than that of original neat diesel mode, which caused the heat release was much more centralized and the peak of heat release was much higher. Under the high load, BDCC mode had two peak values of the heat release rate, the first small peak was formed by the small partial self-ignition of n-butanol, and the second peak was formed by the heat release of n-butanol and diesel compound combustion. The diesel engine operating with the BDCC mode could simultaneously reduce the ${\mathrm{NO}}_{\mathrm{x}}$ and soot emissions but increase the total hydrocarbons (THC) and carbon monoxide (CO) emissions compared with the original neat diesel engine.

This paper focuses on a four-cylinder light-duty diesel engine and analyzes how the coupling action of oxygenated fuel and gas circuit oxygen impact soot generation based on tests where the in-cylinder ambient oxygen concentration is rich, medium, or poor. The test results show that ignition delay period and fuel oxygen content are major factors in soot value decreases, whereas in-cylinder combustion temperature hardly affects soot generation. Further analysis reveals that the weight of influence of ignition delay period and fuel oxygen content on soot generated by combustion of B0 (pure diesel) and B20 (20% n-butyl alcohol + 80% diesel by mass) fuels are different at various in-cylinder oxygen concentrations. For an oxygen content of 0.87% in the fuel, when there is rich oxygen inside the cylinders, the weight of influence on soot generation is 72.73–80.00%; when there is a medium amount of oxygen, the weight of influence is 42.18–72.73%; in the case of scarce oxygen, the weight of influence is 41.43–42.18%. In terms of ignition delay period, when there is rich oxygen, the weight of influence is 20.00–27.27%; in the case of a medium amount of oxygen, the weight of influence is 27.27–57.82%; and for only a little oxygen, the weight of influence is 57.82–58.57%.

With the continuous growth of global energy demand, although the use of fossil fuels has brought economic benefits, it has also brought a series of environmental problems. Especially, greenhouse ga...

To investigate the feasibility of diesel engines with high butanol substitution rate (BSR), the performance and emissions of diesel–butanol dual fuel engines are studied numerically. It i based on a four-cylinder diesel engine, which is modified into a diesel–butanol dual fuel engine with port-injected butanol fuel and direct-injected diesel fuel. The simulation is performed using GT-Power software, and simulation results are validated with the experimental data. The engine speeds are set at 1600, 2300, and 3600 rpm, respectively. The engine load is set at 25%, 50%, and 75% engine load, respectively. The BSR varies from 0% to 80% with an interval of 10%. The results show that, with the increase of BSR, the peak cylinder pressure (PCP), and the maximum pressure rise rate (MPRR) decrease, while the brake mean effective pressure (BMEP) and the indicated thermal efficiency (ITE) increase under various working conditions. Among them, the MPRR increases by 9%–12%, while the ITE increases by 6%–7%. In terms of emissions, the nitrogen oxide (NO_X) decreases obviously (decrease by 32%–54%), while the carbon monoxide (CO) and the hydrocarbons (HC) decrease slightly (CO: decrease by 4%–10%, HC decrease by 3%–4%).