Evaluation of Water-blend Fuels in a City Bus and an Assessment of Performance with Emission Control Devices

Abstract

<div class="htmlview paragraph">The UK government offered a tax incentive to introduce ultra-low sulphur diesel (ULSD) fuels into the market place. This has led rapidly to the use of such a fuel with a consequent reduction in emissions, notably particulates and permits the use of some exhaust after-treatment devices that were formerly precluded.</div> <div class="htmlview paragraph">A water-blend fuel technology has been developed to substantially reduce engine out emissions relative to ULSD and is currently under market evaluation. Use of the fuel requires no engine modifications.</div> <div class="htmlview paragraph">To further evaluate the emissions performance of the technology, a trial was conducted with the Millbrook testing facility, Bedfordshire, England. The trial also considered the impact of such water-blend fuels on existing/future exhaust emission control technology.</div> <div class="htmlview paragraph">On the Millbrook London Transport Bus (MLTB) cycle, the water-blend fuels tested achieved significant reductions in nitrogen oxides (NOx) and particulates over that attained by ULSD. Speciation confirmed that the water-blend fuels tested also gave equivalent or lower levels of unregulated emissions. Further enhancements in total emissions control were achieved through the combination of water-blend fuel with oxidation catalyst and particulate filter traps. No detrimental effect was noted for these fuels with regard to these exhaust emission control technologies.</div> <div class="htmlview paragraph">The data from this programme of work illustrate the viability of water-blend fuels in reducing exhaust emissions alone or in combination with exhaust emission control products.</div>