Stack-like reactors

Methanol Steam Reforming 3 [MSR 3] Electrically Heated Stack-like Reactor... 

Figure 2.7 Close-up view of the experimental set-up and stack-like reactor [25] (source IMM).

Pfeifer et al. [22] used a stack-like reactor ([MSR 3]) for testing of various CuO/ZnO and PdZnO catalyst systems ... 

Water-gas Shift 1 [WGS 1] Stack-like Reactor Applied to Water-gas Shift Testing... 

Germani et al. [82] wash-coated Cu/ZnO catalyst on to micro channels and compared their performance with that of conventional monoliths for the low-temperature water-gas shift. Up to six plates could be put into a stack-like reactor heated by cartridges, which had a maximum operation temperature of600 °C (see Figure 2.47). The reactor had capabilities for measuring the inlet and outlet temperature of the gases via thermocouples. 

Figure 2.50 (a) Mounted stack-like reactor used for the water-gas shift reaction and (b) schematic of the stacked foils [83] (by courtesy of Elsevier Ltd.). 

Preferential Carbon Monoxide Oxidation 4 [PrOx 4] Stack-like Reactor Applied to PrOx... 

A stack-like reactor was applied for catalyst testing for the reaction by Chen et al. [38], Four micro structured foils made of stainless steel formed the stack, which were 340 pm thick, carrying 48 channels 170 pm deep and 500 pm wide (see Figure 2.14). 

Pfeifer et al. used a stack-like reactor heated by cartridges for methanol steam reforming [180]. The aim of this work was a microstructured reformer supplying a 200-W fuel cell for small scale mobile applications. To highlight the dynamic... 

As MSRs are studied in the field of microprocess engineering, together with other devices, in which physical processes occur, some combinations can be found such as stack-like reactors with or integrating external heating and cross-fiow/counterflow heat exchangers/reactors, the last one being used mainly for evaporation purposes. 

One of the most frequently used micro reactor types relies on the use of micro-structured platelets with multiple parallel channels, typically manufactured by methods other than routinely used for chip processing, encased in a housing [3,4, 12, 13, 18, 28-39]. If more than one platelet is used, which is usually done to increase throughput, a stack-like arrangement is preferred for parallel feed. Such stacks are either welded directly from the outside [29, 30], are encompassed by a cover [3,18, 31, 32, 37-39], have end caps with fluidic connectors [12,13, 33] or are inserted into a recess of a housing, which is typically composed of two parts [4, 28, 34-36, 40 1]. 

The band width in this study was limited to 150 mm but could exceed 1000 mm, thus opening a route to large-scale micro structured plate-like reactors comparable to the large-scale micro (or mini) structured heat exchangers from Heatric [96], These are manufactured by diffusion welding of stacked plates (Figure 4.114). 

Early studies with the detailed description of the so-called microstructured reactors (microreactors) are dated 1986 however, theoretical calculations of scientists of the former GDR were not put into practical application (1). A patent of that time describes, very generally, a miniaturized chemical engineering apparatus and systems made by simple fabrication methods. A stack-like arrangement of platelets carrying microchannels and fluid connecting structures was also proposed. 

The optical anisotropy observed in most carbon materials reflects the ordered stacking of graphite-like microcrystalline units that has been recognized to be essential in determining their properties. Pitch-based carbon fiber, electrode and metallurgical cokes, and carbons for nuclear reactors are characterized by their anisotropic texture since this structural factor is fundamentally related to their mechanical, thermal, electronic, and chemical properties (1-5) ... 

Industrially, hydrodesulfurization of oil fractions, like aU hydroprocessing, is carried out catalytically in a fixed bed trickle flow unit. The catalyst is stacked in a packed bed and gas (hydrogen) and liquid (oil) are fed downstream concurrently. The reactor operates in the trickle-flow regime, in which the catalyst pellets are fully wetted with the liquid and both gas and liquid flow along the external surface. 

AECL began to study dry storage for spent nuclear fuel in the early 1970s. Silo-like structures called concrete canisters were first developed for the storage of research reactor enriched uranium fuel and then perfected for spent CANDU NUE fuel. By 1987, concrete canisters were being used for the safe and economical storage of all spent fuel accumulated during the operation of AECL s decommissioned prototype reactors. Each canister contains a stack of spent fuel baskets. 

The Caterpillar micro mixer is an example of a simple, pilot-sized micro mixer-tube reactor that has an internal microstructure with a ramp-like shape inducing recirculation flow patterns, whereas the overall channel structure can be kept fairly large. The volume varies between 1 L/hr to several hundred liters per hour. Several hundreds of precision-engineered, star-shaped platelets can be stacked, and the flow can be distributed. 

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