Dual-fuel strategies can enable replacement of diesel fuel with low reactivity biofuels like hydrous ethanol. Our previous work has shown that dual-fuel strategies using port injection of hydrous ethanol can replace up to 60% of diesel fuel on an energy basis. However, they yield negligible benefits in NOx emissions, soot emissions, and brake thermal efficiency (BTE) over conventional single fuel diesel operation. Pretreatment of hydrous ethanol through steam reforming before mixing with intake air offers the potential to both increase BTE and decrease soot and NOX emissions. Steam reforming can upgrade the heating value of the secondary fuel through thermochemical recuperation (TCR) and produces inert gases to act as a diluent similar to exhaust gas recirculation. This study experimentally investigated a novel thermally integrated steam reforming reactor that uses sensible and chemical energy in the exhaust to provide the necessary heat for hydrous ethanol steam reforming. An off-highway diesel engine was operated at three speed and load settings with varying hydrous ethanol flow rates reaching fumigant energy fractions of up to 70%. The engine achieved soot reductions of close to 90% and minor NOX reductions; however, carbon monoxide and unburned hydrocarbon emissions increased. A first law energy balance using the experimental data shows that efficient TCR effectively upgraded the heating value of the secondary fuel. Overall, hydrous ethanol steam reforming using TCR can lead to 23% increase in fuel heating value at 100% conversion, a limit approached in the conducted experiments.
|Original language||English (US)|
|Title of host publication||Large Bore Engines; Fuels; Advanced Combustion|
|Publisher||American Society of Mechanical Engineers|
|State||Published - 2018|
|Event||ASME 2018 Internal Combustion Engine Division Fall Technical Conference, ICEF 2018 - San Diego, United States|
Duration: Nov 4 2018 → Nov 7 2018
|Name||ASME 2018 Internal Combustion Engine Division Fall Technical Conference, ICEF 2018|
|Other||ASME 2018 Internal Combustion Engine Division Fall Technical Conference, ICEF 2018|
|Period||11/4/18 → 11/7/18|
Bibliographical noteFunding Information:
This research was funded by the Minnesota Corn Research and Promotion Council under grant # 1078-EU. The authors would also like to acknowledge Andrew York and David Wails of Johnson Matthey, Plc for providing the catalysts and wash-coating used in this study.