Energy-ecological efficiency of dual-fuel series plug-in hybrid electric vehicle considering WTW emissions.

This paper discussed the possibility of replacing the internal combustion engine of the series plug-in hybrid electric vehicle (PHEV) powered by gasoline A and Brazilian gasoline in single-fuel mode by one fuelled with 50% bioethanol and 50% biogas in dual-fuel mode. The simulation of the combustion of the fuels selected, such as bioethanol, biogas and gasoline A, was carried out through GASEQ software to calculate the energy-ecological efficiency of the single-fuel and dual-fuel modes. The well-to-pump (WTP) emissions of the bioethanol and biogas production from sugarcane were evaluated through GREET software. The tank-to-wheel (TTW) emissions were determined to each series PHEV operating modes. Thus, the well-to-wheel (WTW) emissions were calculated through the sum of the WTP, TTW and electricity mix emissions. According to the results, the energy-ecological efficiency for the dual-fuel mode was 10.7% and 24.1% higher than that found for the single-fuel mode powered by gasoline and Brazilian gasoline, respectively. The analysis showed that the losses during the biogas production aggravate linearly the WTP emissions, and consequently, the WTW emissions of the series PHEV. Besides that, the dual-fuel mode presented 15.5% and 12.8 less TTW emissions than the single-fuel mode powered by gasoline A and Brazilian gasoline, respectively. Compared to the emission standards, the dual-fuel mode presented TTW emissions 30.5% higher than the European Union emission standard by 2021. Although the dual-fuel mode does not meet any of the emission standards, this engine mode can be an alternative to at least reduce the tailpipe emissions.

Well-to-wheel emissions and abatement strategies for passenger vehicles in two Latin American cities.

More stringent standards for engines and fuels are progressively implemented as alternatives to reduce on-road vehicle emissions. While electric vehicles appear as a perfect alternative since their engines do not emit pollutants, wear and dust resuspension (W&R) and indirect emissions associated with electricity production remain significant sources of pollution. This work compares well-to-wheel emissions (WTW) and abatement strategies for various types of passenger vehicles in Bogotá and Santiago for different pollutants (CO, PM2.5, SO2, and NOx) and greenhouse gases like CO2 equivalent (CO2-Eq). Results show that WTW baseline emissions are more extensive in Bogotá than in Santiago (i.e., 58 and 30% for PM2.5 and CO2-Eq), mainly due to the higher vehicle activity and older state of Bogotá's fleet. We also evaluated extreme scenarios to assess the potential of a given vehicle technology or energy source to reduce emissions. We assessed, in particular, the replacement of all current vehicles by (1) conventional technologies with stricter emission standards and (2) battery electric vehicles powered with different energy resources. Our results indicate that replacing the current fleet with modern combustion technologies has a lower reduction potential than battery electric vehicles, but these reductions largely depend on the energy mix. Substitution by electric vehicles powered with electricity from renewable energies is the most efficient scenario in both cities. Finally, results also stress the importance of the resuspension of deposited road dust and brake and tire wear emissions in both cities as a crucial source of PM2.5, which must be better controlled.

Life cycle assessment of gasoline production and use in Chile.

Gasoline is the second most consumed fuel in Chile, accounting for 34% of the total fuel consumption in transportation related activities in 2012. Chilean refineries process more than 97% of the total gasoline commercialized in the national market. When it comes to evaluating the environmental profile of a Chilean process or product, the analysis should consider the characteristics of the Chilean scenario for fuel production and use. Therefore, the identification of the environmental impacts of gasoline production turns to be very relevant for the determination of the associated environmental impacts. For this purpose, Life Cycle Assessment has been selected as a useful methodology to assess the ecological burdens derived from fuel-based systems. In this case study, five subsystems were considered under a "well-to-wheel" analysis: crude oil extraction, gasoline importation, refinery, gasoline storage and distribution/use. The distance of 1 km driven by a middle size passenger car was chosen as functional unit. Moreover, volume, economic and energy-based allocations were also considered in a further sensitivity analysis. According to the results, the main hotspots were the refining activities as well as the tailpipe emissions from car use. When detailing by impact category, climate change was mainly affected by the combustion emissions derived from the gasoline use and refining activities. Refinery was also remarkable in toxicity related categories due to heavy metals emissions. In ozone layer and mineral depletion, transport activities played an important role. Refinery was also predominant in photochemical oxidation and water depletion. In terms of terrestrial acidification and marine eutrophication, the combustion emissions from gasoline use accounted for large contributions. This study provides real inventory data for the Chilean case study and the environmental results give insight into their influence of the assessment of products and processes in the country. Moreover, they could be compared with production and distribution schemes in other regions.