Preferential integrated reactor

Figure 2.60 Integrated reactor/heat exchanger for the preferential oxidation of carbon monoxide developed by Eindhoven University and IMM [89] (source IMM).

This system includes several mixing and heat exchange units. A concept for an integrated, microtechnology-based fuel processor was proposed by PNNF [8]. As examples for unit operations which may be included in future integrated systems the same publication mentions reactors for steam reforming and/or partial oxidation, water-gas shift reactors and preferential oxidation reactors for carbon monoxide conversions, heat exchangers, membranes or other separation components. 

Design of 50 kW integrated fuel processor, which includes reformer, shift reactor, steam generator and preferential oxidation reactor. 

Achieve high efficiency through integration of steam reforming, water gas shift, and preferential oxidation reactors with microchannel recuperative heat exchangers, fuel and water vaporizers, condensers, and separators. 

Dokupil et al. [129] described a monolithic preferential oxidation reactor operated at 100°C temperature and 15 000h GHSV. It carried an integrated heat exchanger to improve its thermal management. 

Ersoza et al. (2005) studied a 100 kW net electrical power PEM fuel cell system consisting of an autothermal reformer, high and low temperature shift reactors, a preferential oxidation reactor, a PEM fuel cell, a combustor and an expander. Intensive heat integration within the PEM fuel cell system was necessary to achieve acceptable net electrical efficiency levels. The fuel cell stack efficiency has been calculated as a function of the number of cells (500-1250 cells). The obtained net electrical efficiency levels are between 30% (500 cells) and 37% (1250 cells) and they are comparable with the conventional gasoline based internal combustion engine systems, in terms of the mechanical power efficiency. 

Preferential Carbon Monoxide Oxidation 5 [PrOx 5] Integrated Heat Exchanger/Reactor for PrOx... 

Schuessler et al. [85] of XCELLSiS (later BALLARD) presented an integrated methanol fuel processor system based on autothermal reforming, which coupled fuel/water evaporation with exothermic preferential oxidation (PrOx) of carbon monoxide. The reactor technology was based, in contrast to most other approaches, on a sintering technique. 

A conventional FPS, shown in Fig. 14.2, includes a reformer, two WGS reactors, and two Preferential Oxidation (PrOx) reactors, located downstream of the WGS. For PEM fuel cells, it is a necessity to assure < 10 ppm of CO in the cell stack. These reactors form a considerable fraction of the FPS weight, volume, and cost. Replacing this train by an integrated hydrogen permeation selective membrane on the water gas shift reactor, shown in Fig. 14.3, results in a considerable reduction in the number of components, cost, and volume of the FPS. This will make fuel cell power plants practical and affordable for power generation in a wide range of applications, especially for residential and transportation. Numerous published works [8, 9] in the area of catalytic membrane reactors can be quoted in the experimental [10] and numerical [11, 12] domains. 

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