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Biodiesel is a promising renewable alternative fuel, which can be used in diesel‐electric hybrid vehicles to potentially bring one kind of clean vehicle on the road. However, the fuel property variation can cause impacts to the powertrain and aftertreatment systems. In this paper, biodiesel's influence on post‐injection effects is studied. Experimental results are obtained to demonstrate the differences between diesel and biodiesel, and to build up fuel‐dependent maps of engine torque, temperature, and emissions. Utilizing those maps, an aftertreatment warm‐up approach compatible with both fuels is developed by strategically enabling double post injections. Finally, a supervisory controller based on model predictive control method is designed to optimize and balance the tradeoff between hybrid vehicle fuel economy and tailpipe emissions. Simulations are conducted for both fuels with or without the proposed control strategy. The validation results show that for both fuels, the controller can significantly reduce tailpipe emissions by successfully regulating the catalyst temperature to the desired range sacrificing fuel economy. And for biodiesel, additional fuel cost is required in order to realize the tradeoff.

The combination of Irish potato waste (IPW) and poultry waste (PW) can form a synergy resulting into an effective substrate for a better biogas production due to some materials they contain. In this work, optimization and kinetic study of biogas production from anaerobic digestion of IPW and PW was investigated. Response surface methodology (RSM) was applied to optimize conditions such as initial pH, solids concentrations and waste ratios. The anaerobic digestion of the two wastes was carried out in the mesophilic condition and Box-Behnken design (BBD) was used to develop and analyze a predictive model which describes the biogas yield. The results revealed that there is a good fit between the experimental and the predicted biogas yield as revealed by the coefficient of determination (R2) value of 97.93%. Optimization using quadratic RSM predicts biogas yield of 19.75% at the optimal conditions of initial pH value 7.28, solids concentration (w/v) 9.85% and waste ratio (IPW:PW) 45:55%. The reaction was observed to have followed a first order kinetics having R2 and relative squared error (RSE) values of 90.61 and 9.63% respectively. Kinetic parameters, such as rate constant and half-life of the biogas yield were evaluated at optimum conditions to be 0.0392 day-1 and 17.68 days respectively. The optimum conditions and kinetic parameters generated from this research can be used to design real bio-digesters, monitor substrate concentrations, simulate biochemical processes and predict performance of bio-digesters using IPW and PW as substrate.

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