FACE - Novel Integrated Fuel Reformer-Aftertreatment System for Clean and Efficient Road Vehicles

Lead Research Organisation: Brunel University
Department Name: Institute of Energy Futures

Abstract

Modern vehicles fuel economy has been improved since 2010 by approximately 20% and this has been achieved through engineering advances that have led to engine efficiency improvements, reduction in vehicle mass, introduction of hybrids. Vehicle manufacturers have managed to meet the mandatory 2015 CO2 levels, however according to their current announcements they are all still away by 30% to 15% from the 2020/21 target of 95 g/km. Achieving the necessary additional fuel economy improvement for 2020 and beyond requires the introduction of other unconventional technological approaches.

Despite substantial improvements in the emissions control technologies for road transport, which have been resulted in improved air quality over the past decade, there are still significant air quality problems throughout the UK and the EU, especially in urban and densely populated areas
Exhaust gas fuel reforming is a technique that utilises the engine exhaust heat, H2O, CO2 and fresh fuel to produce H2 rich gas through the promotion of primarily endodermic reactions
Fuel reforming for IC engine technologies has been discussed for years but has never been implemented. The combination of present challenges in the emission reduction requirements in road transport and the improved fuels quality in recent years provides a unique opportunity for a successful fuel reforming process to be utilized in the global aftertreatment market.

In the "first stage" (WP1) the fuel reformer will be designed and integrated within the engine exhaust to provide small reformate/H2 concentrations to the aftertreatment system when required. In the "second stage" (WP2) the fuel reforming catalyst will be amalgamated within the aftertreatment, into one novel compact integrated catalyst brick, designed using additive manufacturing techniques, to improve further response time to engine changes and emission and simplify its operation, costs, complexity and control. In addition to emission benefits, fuel economy improvements (taking into account the small quantity of fuel in the reformer to generate the required ppm of H2) in GDI and Diesel engine, though combinations of more efficient engine calibration, reduced pumping losses and the absence of disruptive aftertreatment control strategies (i.e. aftertreatment systems activity and regeneration achieved through the substantial use of fuel).

Publications

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Description Urea-based selective catalytic reduction (SCR) system is widely used to reduce NOx emission from diesel engines. The NOx conversion efficiency, as well as the adverse effects of wall-wetting is mainly influenced by the atomization characteristics of urea water solution (UWS). Under extreme winter conditions, the UWS can reach temperatures as close as its freezing temperatures. Under these adverse weather conditions the flow and spray characteristics of UWS are not well defined. In order to gain an understanding of these factors, an attempt has been made in this work to study the effect of varying the temperatures of UWS to evaluate the spray characteristics of UWS used in SCR systems. In this work, the temperatures of UWS were varied from 20°C to -10°C to consider the variations in the ambient temperatures from normal up to freezing point of UWS. Effect of temperature of UWS was significant at lower gauge pressures (?P) of the atomizing air. Bag breakup was observed at 20°C and ?P= 500 mbar condition in near-nozzle region of the spray. On the other hand, almost intact liquid core was observed at -10°C and 500 mbar condition suggesting poor atomization of UWS spray. This observation was confirmed in drop-size distributions where large number of big droplets was observed at -10°C and low ?P conditions. Drop-size distributions improved with increase in ?P at all temperature conditions showing marginal influence of temperature of UWS at high ?P conditions. This underlines the need of operating UWS systems at high ?P conditions to mitigate the effect of sub-atmospheric temperatures UWS spray characteristics.
Exploitation Route Design and operation guidelines for SCR systems for IC engine NOx emissions control.
Sectors Energy,Transport