Reactor configurations architecture

Gas-diffusion to surfaces is mainly dependent on reactor configuration (geometry) and is to be taken under considerations when the membrane architecture includes a porous layer (grain size, porosity, interconnection shapes and dimensions,...). 

Sherwin-Williams has developed such a polymer process control system. The methodology used to accommodate the contrasting requirements has two key elements. First, the software is based on a simple architecture that places the definition of changing reactor hardware elements and characteristics in easily modified configuration files (5). Second, the language uses a small number of basic commands to describe formulations and reactor control. Complex operations are described by reference to commands tables (macros) built using several basic commands or other macros. 

The optimal configuration of a valve or flow-through system is achieved by mounting the reactors at a stationary location in the instrument, thus dictating a closed architecture... 

In configuration 1, the reformer and membrane module (RMM) where hydrogen selective membrane is assembled in separation modules applied downstream to reaction units so that the process scheme is composed by a series of reaction-separation units (staged membrane reactor architecture)... 

The coupling of membrane separation modules and the conventional WGSR reactors through this kind of architecture results in a better overall efficiencies (97.5% as compared to 91% for the reference case). By this configuration, the fuel stream is enriched in H2 by the membrane reactor and requires only polishing by PSA. 

The typical and most straightforward configuration for a membrane reactor is composed of two concentric tubes, where the catalyst is packed in the annular zone while the inner tube is the membrane itself (closed architecture) as shown in Fig. 11.2. 

In an alternative configuration, the selective membrane is placed outside the reactor in units located downstream (open architecture. Fig. 11.3). In this case, after the membrane separation module another reaction unit is required, in which the enhancement in hydrocarbon conversion may be observed. 

The two configurations both have several benefits and drawbacks. Globally, at the same operating conditions, the closed architecture is more compact, shows ease of scalability and avoids catalyst waste however, its major drawback is in the technological difficulties involved in designing and maintaining the reactor. 

Finally, when a membrane reactor was employed in open architecture configuration along with a catalyst effectiveness factor of 0.6, the hydrogen recovery factor was evaluated as a function of the membrane permeation surface. The results are shown in Fig. 11.6. 

A distinctive feature of microreactors is the microchannels for fluid flow. MMRs are mainly characteristic of such microchannels with anchored catalysts for reactions and miniature membranes to perform separation, which are formed on the porous ceramic or metal supports. Based on the configuration and architecture of the reactor, MMRs can be classified into two categories plate type and tubular type. 

The number, type, function, location, and size of required valves would have ultimately depended on the selected system architecture for the Reactor module Reactor Coolant segment (number of Brayton unit loops and shared components - see Section 3). As stated in Section 6, the current SNPP heat balance assumed a check valve and isolation valve would be included at the compressor outlet. Valve location and function is dependent on the specific plant configuration. Isolation valves may eliminate the need for check valves. 

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