Biomass has the potential to become an important source of energy for future automotive fuels. Recent biological and chemical improvements to the conversion of biomass-derived carbohydrates have produced high yields of liquid 2,5-dimethylfuran (DMF). This discovery has made DMF a possible substitute for petroleum-based gasoline, because they share very similar physicochemical properties, which are superior to those of ethanol. In the present study, experiments have been carried out on a single-cylinder gasoline direct-injection (GDI) research engine to study the performance of DMF benchmarked against gasoline and what is considered to be the current biofuel leader, ethanol. Initial results are very promising for DMF as a new biofuel; not only is the combustion performance similar to commercial gasoline, but the regulated emissions are also comparable.

No abstract

Although exhaust gas recirculation (EGR) is an effective strategy for controlling the levels of nitrogen oxides (NO(X)) emitted from a diesel engine, the full potential of EGR in NO(X)/PM trade-off and engine performance (i.e., fuel economy) has not fully been exploited. Significant work into the cause and control of particulate matter (PM) has been made over the past decade with new cleaner fuels and after-treatment devices emerging to comply with the current and forthcoming emission regulations. In earlier work, we demonstrated that engine operation with oxygenated fuels (e.g., biodiesel) reduces the PM emissions and extends the engine tolerance to EGR before it reaches smoke-limited conditions. The same result has also been reported when high cetane number fuels such as gas-to-liquid (GTL) are used. To further our understanding of the relationship between EGR and PM formation, a diesel particulate filter (DPF) was integrated into the EGR loop to filter the recirculated soot particulates. The control of the soot recirculation penalty through filtered EGR (FEGR) resulted in a 50% engine-out soot reduction, thus showing the possibility of extending the maximum EGR limit or being able to run at the same level of EGR with an improved NO(X)/soot trade-off.

No abstract

Exhaust gas recirculation (EGR) is currently widely used in commercial diesel engines to provide an effective solution in reducing the levels of nitrogen oxide (NO X ) emissions. However, this currently comes at the expense of an exponential increase in particulate matter (PM) emissions resulting directly from the dilution effect (i.e. reduction in oxygen availability), as well as a further penalty arising from the recirculation of the exhaust emissions such as soot and hydrocarbons. In our earlier work it was observed that filtered EGR (FEGR) was able to play a significant role in controlling the soot recirculation penalty and thus improve the overall NO X /soot trade-off. In order to further our understanding of the effect of recirculated exhaust gases and in particular recirculated soot and hydrocarbon (HC), comparisons were made between standard EGR, FEGR and pure nitrogen (N 2 ), a direct cleaner replacement of the exhaust gas. When implementing FEGR, a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) were introduced into the exhaust to not only filter the soot particulates but reduce the recirculation of HC which can play a role in particulate surface growth. It was observed that the recirculated HC species and soot particles (especially at high load and EGR ratios) play a role in promoting the production and growth of further particles within the combustion chamber. Similarly, by comparing at the same O 2 intake concentration as that of FEGR and introducing N 2 as the EGR replacement gas, it was possible to correlate the increase in engineout mass of soot with EGR to the recirculation of soot particles, HC species as well as the presence of H 2 O and CO 2 .