Fuel cell reforming system with carbon dioxide removal
A power generation system includes a fuel cell including an anode that generates a tail gas. The system also includes a hydrocarbon fuel reforming system that mixes a hydrocarbon fuel with the fuel cell tail gas and to convert the hydrocarbon fuel and fuel tail gas into a reformed fuel stream including CO 2 . The reforming system further splits the reformed fuel stream into a first portion and a second portion. The system further includes a CO 2 removal system coupled in flow communication with the reforming system. The system also includes a first reformed fuel path coupled to the reforming system. The first path channels the first portion of the reformed fuel stream to an anode inlet. The system further includes a second reformed fuel path coupled to the reforming system. The second path channels the second portion of the reformed fuel stream to the CO 2 removal system.
1. A method of generating electric power with a power generation system utilizing a fuel cell, said method comprising:
channeling a fuel to an inlet of a solid oxide fuel cell anode;
generating a tail gas stream including carbon dioxide (CO 2 ) in the solid oxide fuel cell anode and discharging the tail gas stream from an outlet of the fuel cell anode;
channeling the tail gas stream to a hydrocarbon fuel reforming system;
mixing a hydrocarbon fuel with the tail gas stream to form a fuel/tail gas mixture stream;
at least partially converting the fuel/tail gas mixture stream into a reformed fuel stream including CO 2 ;
splitting the reformed fuel stream including CO 2 into a first portion and a second portion, wherein the first portion includes a hot partially reformed fuel stream;
channeling the first portion of the reformed fuel stream including CO 2 to the inlet of the solid oxide fuel cell anode;
channeling the second portion of the reformed fuel stream to a CO 2 removal system;
wherein channeling the second portion of the reformed fuel stream including CO 2 to a CO 2 removal system comprises decreasing a CO 2 concentration in the first portion of the reformed fuel stream including CO 2 comprising:
channeling the second portion of the reformed fuel stream including CO 2 to a solvent-based CO 2 absorber;
transferring at least a portion of the CO 2 in the second portion of the reformed fuel stream including CO 2 to a CO 2 -lean solvent stream, and
forming a CO 2 -rich solvent stream and a reformed fuel stream without CO 2 ; and channeling the reformed fuel stream without CO 2 into the hot partially reformed fuel stream.
2. The method in accordance with claim 1 , wherein decreasing a CO 2 concentration in the first portion of the reformed fuel stream including CO 2 further comprises: channeling the CO 2 -rich solvent stream to a rich solvent reboiler; adding heat into the rich solvent reboiler from at least one of a combustion engine exhaust stream and a heat pump.
3. The method in accordance with claim 2 , wherein adding heat into the rich solvent reboiler from at least one of a combustion engine exhaust stream and a heat pump comprises:
splitting the reformed fuel stream including CO 2 into a third portion; and
channeling the third portion of the reformed fuel stream including CO 2 to a combustion engine and generating the engine exhaust stream.
4. The method in accordance with claim 1 , wherein decreasing a CO 2 concentration in the first portion of the reformed fuel stream including CO 2 further comprises transferring heat from the CO 2 -lean solvent stream to the CO 2 -rich solvent stream through a solvent recuperator, thereby preheating the CO 2 -rich solvent stream prior to entry into the rich solvent reboiler.