Power Generation Characteristics of Pulse Jet Rechargeable Direct Carbon Fuel Cells at Different Isooctane Fuel Supply Frequency

Abstract

Power generation tests of pulse jet (PJ) rechargeable direct carbon fuel cells (PJ-RDCFCs), which supply small amounts of isooctane to the anode by pulse jetting, were conducted at different PJ supply frequency and for different PJ supply amount. PJ-RDCFCs could control power density by controlling the supply frequency. At 1 pulse/sec, power generation characteristics of PJ-RDCFCs approached flow-type. At lower supply frequency, power generation characteristics approached batch-type and fuel utilization becomes higher. Fuel utilization also became higher with decreasing PJ supply amount. In the reaction mechanism of a PJ-RDCFC, the contributing species for power generation might be hydrogen, carbon monoxide and hydrocarbons when the PJ supply frequency is high (≈1 pulse/sec). With decreasing supply frequency, carbon which has lower reactivity became to contribute to the power generation. In conclusion, the electrochemical reactions in the anode side in a PJ-RDCFC can be controlled by adjusting the pulse jet supply frequency.

Critical Review of Carbon Conversion in “Carbon Fuel Cells”

“…152 Naturally, this type of CFC necessarily operates in batch mode, where the amount of carbon deposited by pyrolysis is rather limited, and hence provides only limited energy capacity. To overcome this shortcoming, more recent work 153 proposed a rechargeable operation mode that involved pulsed jet injection of iso-octane on to the anode at a relatively high frequency of 1 pulse/s. They demonstrated current densities up to 6000 A/m 2 at 900 °C.…”

Novel Electrode Evaluation Method for Pulse Jet Solid Oxide Fuel Cells using Liquid Hydrocarbon Fuels

“…Previously, we estimated the relationship between U fuel and the reactions in each cycle from electrochemical measurements in the PJ-SOFCs. 40,41 When U fuel is set at a sufficiently small value, PJ-SOFC power generation involves the thermal decomposition of both isooctane and hydrocarbon (Eqs. 3 and 4), which have high partial pressures, and the direct electrochemical reaction of hydrocarbon fuel (Eq.…”

“…The relationship between U fuel and the reactions in the PJ-SOFC are described above. 40,41 In the present study, U fuel,end was fixed at 60%. Therefore, Eqs.…”

“…Against this background, we previously proposed a new SOFC that directly utilizes hydrocarbons. [40][41][42] In this cell, called a pulse jet SOFC (PJ-SOFC), a liquid-fuel injector used in gasoline engines is placed below the fuel electrode, which is directly supplied with liquid hydrocarbon fuel (see Fig. 1).…”

Effects of Gas Composition Just before Fuel Pulses on Power Generation Characteristics at Different Fuel Supply Frequency in Pulse Jet-Rechargeable Direct Carbon Fuel Cells

“…To address these drawbacks, we developed a "Pulse Jet-Rechargeable Direct Carbon Fuel Cell (PJ-RDCFC)" that can be supplied with liquid hydrocarbon directly (22). In a PJ-RDCFC, small amounts of isooctane, which is the gasoline model, are supplied via pulse jet at constant time intervals.…”