Among primary alcohols, bio-n-butanol is considered as a promising alternative fuel candidate. However, relatively low production efficiency and high cost of component recovery from the acetone-n-butanol-ethanol (ABE) or isopropanol-n-butanol-ethanol (IBE) fermentation processes hinders industrial-scale production of bio-n-butanol. Hence it is of interest to study the intermediate fermentation product, i.e. ABE and IBE as a potential alternative fuels. However, for fuel applications, the IBE mixture appears to be more attractive than ABE due to more favorable properties of isopropanol over acetone, such as being less corrosive to engine part, higher energy density and octane number. In this study, an experimental investigation on the performance, combustion and emission characteristics of a port fuel-injection SI engine fueled with IBE-gasoline blends was carried out. By comparisons between IBE-gasoline blends with various IBE content (0 vol.%-60 vol.% referred to as G100-IBE60) and more commonly used alternative alcohol fuels (ethanol, n-butanol and ABE)-gasoline blends, it was found that IBE30 performed well with respect to engine performance and emissions, including brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), carbon monoxide (CO), unburned hydrocarbons (UHC) and nitrogen oxides (NO x). Then, IBE30 was selected to be compared with G100 under various equivalence ratio (Φ=0.83~1) and engine load (300 and 500 kpa BMEP). Overall, higher BTE (0.04-4.3%) and lower CO (4%), UHC (15.1-20.3%) and NO x (3.3-18.6%) emissions were produced by IBE30 compared to G100. Therefore, IBE could be a good alternative fuel to gasoline due to the environmentally benign fermentation process (from non-edible biomass feedstock and without recovery process) and the potential to improve energy efficiency and reduce pollutant emissions.

Ethanol is the most extensively used oxygenate for spark ignition (SI) engines. In comparison with ethanol, n-butanol exhibits a number of desirable properties for use in SI engines, which has proved to be a very promising oxygenated alternative fuel in recent years. However, the dehydration and recovery of bio-n-butanol consume extra money and energy in the acetone-n-butanolethanol (ABE) fermentation process. Hence, we focus on the research of ABE as a potential oxygenated alternative fuel in SI engines. e combustion, performance, and emission characteristics of B30, E30, ABE30 (i.e., 30 vol.% n-butanol, ethanol, and ABE blended with 70 vol.% gasoline), and G100 (pure gasoline) were compared in this study. e comparison results between B30, E30, and ABE30 at stoichiometric conditions show that ABE30 presents retarded combustion phasing, higher brake thermal efficiency, lower CO emissions, higher UHC emissions, and similar NO x emissions. In comparison with G100 under various engine loads and equivalence ratios, for the most part, ABE30 exhibits 1.4% higher brake thermal efficiency, 14% lower carbon monoxide, 9.7% lower unburned hydrocarbons, and 23.4% lower nitrogen oxides. It is indicated that ABE could be served as the oxygenate in spark ignition engine due to its capability to improve energy efficiency and reduce pollutant emissions.

Bio-butanol is typically produced by acetone-butanol-ethanol (ABE) fermentation, however, the recovery of bio-butanol from the ABE mixture involves high costs and energy consumption.Hence it is of interest to study the intermediate fermentation product, i.e. ABE, as a potentially alternative fuel. In this study, an experimental investigation of the performance, combustion and emission characteristics of a port fuel-injection SI engine fueled with ABE-gasoline blends was carried out. By testing different ABE-gasoline blends with varying

To face the challenges of fossil fuel shortage and stringent emission norms, there is growing interest in the potential usage of alternative fuels such as bio-ethanol and bio-butanol in internal combustion engines. More recently, Acetone-Butanol-Ethanol (ABE), the intermediate product of bio-butanol fermentation, has been gaining a lot of attention as an alternative fuel. The literature shows that the acetone in the ABE blends plays an important part in improving the combustion performance and emissions, owing to its higher volatility. Acetone and ethanol are the low-value byproducts during bio-butanol production, so using acetone and ethanol as fuel additives may have both economic and environmental benefits. This study focuses on the differences in combustion, performance and emission characteristics of a port-injection spark-ignition engine fueled with pure gasoline (G100), ethanol-containing gasoline (E10 and E30) and acetone-ethanol-gasoline blends (AE10 and AE30 at A:E volumetric ratio of 3:1). The tests were conducted at 1200 RPM, under gasoline maximum brake torque (MBT) at 3 bar and 5 bar brake mean effective pressure (BMEP). Performance and emission data were measured under various equivalence ratios. Based on the comparison of combustion phasing, brake thermal efficiency, brake specific fuel consumption and various emissions of different fuels, it was found that using acetone as an oxygenate additive with the default ECU calibration (for gasoline) maintained the thermal efficiency and showed lower unburned HC emissions.

No abstract

The accurate air-fuel ratio (AFR) control is crucial for the exhaust emission reduction based on the three-way catalytic converter in the spark ignition (SI) engine. The difficulties in transient cylinder air mass flow measurement, the existing fuel mass wall-wetting phenomenon, and the unfixed AFR path dynamic variations make the design of the AFR controller a challenging task. In this paper, an adaptive AFR regulation controller is designed using the feedforward and feedback control scheme based on the dynamical modelling of the AFR path. The generalized predictive control method is proposed to solve the problems of inherent nonlinearities, time delays, parameter variations, and uncertainties in the AFR closed loop. The simulation analysis is investigated for the effectiveness of noise suppression, online prediction, and self-correction on the SI engine system. Moreover, the experimental verification shows an acceptable performance of the designed controller and the potential usage of the generalized predictive control in AFR regulation application.

Accurate AFR control with TWC is a significant method to reduce the exhaust emission of SI engines. To follow the up to date model-based methodology in automotive industries, a virtual engine simulation platform was carried out to simulate a SGMW B15 engine based on enDYNA and improved by adding the AFR path dynamic models. Experiments and simulation results were compared for the model validation both about the engine performance at steady state, and especially the AFR path transient response. Also a soft ECU model was designed for the control algorithm implementation. Simulation results shows that the engine model is appropriate for simulating SI engine operated at steady and transient state, and the close-loop PID controller has better performance for suppressing the overshoot of AFR signal during transient throttle position varying. The simulation model described in this work could support the AFR control algorithm development as a proper virtual engine control objects.

The selective catalytic reduction (SCR) decomposition of nitrogen oxide (de-NO x ) process in coal-fired power plants not only displays nonlinearity, large inertia and time variation but also a lag in NO x analysis; hence, it is difficult to obtain an accurate model that can be used to control NH 3 injection during changes in the operating state. In this work, a novel dynamic inferential model with delay estimation was proposed for NO x emission prediction. First, k -nearest neighbour mutual information was used to estimate the time delay of the descriptor variables, followed by reconstruction of the phase space of the model data. Second, multi-scale wavelet kernel partial least square was used to improve the prediction ability, and this was followed by verification using benchmark dataset experiments. Finally, the delay time difference method and feedback correction strategy were proposed to deal with the time variation of the SCR de-NO x process. Through the analysis of the experimental field data in the steady state, the variable state and the NO x analyser blowback process, the results proved that this dynamic model has high prediction accuracy during state changes and can realize advance prediction of the NO x emission.