Further Development of an On-Board Distillation System for Generating a Highly Volatile Cold-Start Fuel

Octane-On-Demand: Onboard Separation of Oxygenates from Gasoline

“…These interactions promote the partitioning of the alcohols into the polar media, which can be separated from the fuel. Alcohols can then be recovered from the polar media through a distillation process, similar to those previously reported, using heat from the engine, the engine exhaust, or the catalytic converter. − ,− , …”

“…As previously noted, an onboard distillation system (OBDS) has been shown to be effective at separating low boiling point fractions from gasoline or E85 gasoline. ,,− Whereas these systems used distillation to separate a gasoline stream into two components, approaches in this paper require the alcohol-rich sorbent and gasoline to be physically separated, prior to heating the sorbent and recovering the alcohol. Separation of the gasoline and sorbent does not need to be complete for an OBS–OOD system to be effective.…”

“…Leveraging existing vehicle systems is essential to limit OBS complexity and enhance efficiency. The ability to use heat from the engine coolant or engine exhaust, as well as active or passive cooling using air circulation, or by preheating the gasoline feed, has been considered or tested in both vehicles and laboratory systems. ,− ,− , For the three separation approaches we have presented, the relatively low temperatures required for recovering alcohols and regenerating separation media (Table ) are in keeping with temperatures available from these sources; however, an onboard resource not previously required, or considered, is CO 2 , which could be provided from engine exhaust. Whereas two of our approaches, ILs and EDA-SAMMS, do not require the use of CO 2 for effective separation, the two switchable-polarity solvents tested here, TMG and K1, require CO 2 to trigger either a reaction with an alcohol, or to trigger phase separation of the polar base (Figure ), respectively.…”

“…The first onboard separation (OBS) of gasoline and ethanol used distillation to fractionate the high- and low-volatility fuel components in E85 gasoline, , resulting in a cold-start fuel containing about 40% ethanol by volume . The next iteration of the onboard distillation system was developed to mitigate cold-start emissions from nonethanolic fuels, providing a highly volatile fuel ( T 90 < ∼100 °C) and enabling combustion with reduced enrichment during cold-start and catalyst warm-up. , As noted by Morganti et al , automakers are investigating the feasibility of onboard distillation of E10 gasoline as an enabling approach for OOD. , These OBS approaches do not require fuel storage as the separated fuel component is immediately consumed; however, in combination with an OOD application, storage for the high- and low-octane fuel components is needed. Figure shows the basic components for a generalized OBS–OOD system, which is representative of approaches presented in the literature as well as those presented in this work.…”

“…39 The next iteration of the onboard distillation system was developed to mitigate cold-start emissions from nonethanolic fuels, providing a highly volatile fuel (T 90 < ∼100 °C) and enabling combustion with reduced enrichment during cold-start and catalyst warmup. 40,41 As noted by Morganti et al, automakers are investigating the feasibility of onboard distillation of E10 gasoline as an enabling approach for OOD. 23,37 These OBS approaches do not require fuel storage as the separated fuel component is immediately consumed; however, in combination with an OOD application, storage for the high-and lowoctane fuel components is needed.…”