Gas Application Technologies (Household Use)
Fuel processor for small size fuel cells
Fuel Cell Development Dept.
Outline
Osaka Gas has developed compact fuel processors for 1kW-class polymer electrolyte fuel cells (PEFC). High thermal efficiency, extremely low CO concentration, long durability and low cost have been achieved by using Osaka Gas's proprietary catalysts to meet all the requirements of fuel processors for residential PEFC cogeneration system. Osaka Gas has already transferred its fuel processing technology on non-exclusive basis to PEFC system manufacturers.
Characteristics
- All in one package
All elements (desulfurizer, steam reformer, CO shift converter, CO removal reactor, steam generator, burner and heat exchangers) are integrated in a single package. - High thermal efficiency
High thermal efficiency*1 (over 82% (HHV) for 1kW,) is achieved by both low S/C and low O2/CO ratios operation due to Osaka Gas's proprietary high performance catalysts, and by low heat loss arrangement and integration of each reactor. - Extremely low outlet CO concentration
Extremely low CO concentration (below 1 ppm) in the product gas is constantly achieved by highly selective CO preferential oxidation catalyst. - No catalyst exchange
The Fuel Processor is designed to operate using Japanese city gas (natural gas 13A, 5 ppm-S) without exchanging any catalysts (desulfurization, steam reforming, CO shift and CO preferential oxidation catalysts) for 90,000 hours, based on the abundant experiences for PAFC reformer durable for 50,000 hours. - Long durability
Stable product gas and thermal efficiency have been demonstrated for more than 40,000 hours continuous operation, and for more than 3,000 times of start and stop operation, and no deterioration tendency was observed. - Simple temperature control
By controlling temperatures of only two points (steam reformer and CO removal), the temperatures of all reactors are autonomously balanced.. - Low cost
Low production cost can be expected by using common plate type elements for almost all reactors producible by stamp formation and automatic welding.
Appearance
Inside (side view)
Product Specifications
| Class | Net 1kWe | Net 750We | Net 500We | |
|---|---|---|---|---|
| Raw material | Natural gas(Liquefied petroleum gas) | |||
| Reforming process | Steam reforming | |||
| CO removal process | Preferential oxidation | |||
| Burner fuel | Anode off gas and/or Natural | |||
| CO in product gas | < 10 ppm (< 1 ppm (initial)) | |||
| Thermal efficiency (HHV) at normal output | 82% | 82% | 80% | |
| Life (without exchanging any catalysts) | 90,000 hours (5 ppm-S in natural gas) | |||
| Size (including thermal insulation, without outer piping) | W280*L450*H390 | W250*L375*H375 | W260*L350*H400 | |
| Start-up time | ca. 1 hour | |||
| Turn down (net available H2 basis) | 0% (Self-sustainable) - 100% | |||
| Load change rate at increasing output | > 1 W/sec*2 | |||
| Load change rate at decreasing output | Moment*2 | |||
| Designed start-up and shut-down times | 1,200 times | |||
| Operating Pressure | < 20 kPa | |||
| Pressure drop of fuel line | < 5 kPa | |||
| Flow rate of natural gas*3 for process at nominal output | 4.2 NL/min. | 3.4 NL/min. | 2.1 NL/min. | |
| Steam / Carbon ratio at steam reformer | 2.5 | |||
| O2/CO ratio at CO removal reactor | 1.5 | |||
| Flow rate of product gas at normal output (dry) | 23 NL/min. | 18 NL/min. | 11.5 NL/min. | |
| Product gas (dry %) | H2 | > 75 vol.% | ||
| N2 | < 3 vol.% | |||
| CH4 | < 2 vol.% | |||
| CO | < 1 ppm | |||
| O2 | ca. 20 vol.% | |||
*1 Thermal efficiency = Enthalpy of H2 consumed
in cell stack / (Process natural gas + Burner natural gas)
*2 depends on control procedure.
*3 Composition of natural gas: CH4 = 89 vol.%, C2H6 = 7 vol.%, C3H8 = 3 vol.%, C4H10 = 1 vol.%
*2 depends on control procedure.
*3 Composition of natural gas: CH4 = 89 vol.%, C2H6 = 7 vol.%, C3H8 = 3 vol.%, C4H10 = 1 vol.%
