Since 1997 a lot of testing programmes on engine and vehicles test benches has been carried out to prove the environmental effects of this emulsified fuel (reduction of NOx, PM and black smoke).
The introduction on the world-wide market of new engine and/or post-treatment technologies (common rail, unit injectors and Diesel Particulate Filters) designed to meet the increasingly severe emissions standards represents a major challenge to the producers of emulsified fuels. Indeed, the compatibility of the emulsions with these new hardware technologies must clearly be demonstrated if emulsified fuels want to retain their rank amongst the clean fuels offer.
This presentation is addressing this issue by giving an outline of the strategy and test procedures which had to be followed in order to check on the compatibility of the emulsion tested with these technologies being introduced across Europe. In addition, DPF soot loading and regeneration have been investigated. For that purpose, accelerated engine bench soot loading process and filter regeneration characterisation testing have been developed. Testing and measurements using both emulsion and diesel fuel (with identical sulphur level) have been compared.
The test results show that with this emulsion:
soot loading process of the filter is drastically longer compared to diesel fuel,
filter regeneration after soot loading period of about 6 g/l is much faster,
regeneration of soot by NO2 is effective at lower temperature,
Those results can be related to changes in engine out PM emissions when using the tested emulsion: soot level is reduced by 65 % but also PM composition is modified.