Simulator reformer

To facilitate the maintenance and updating of plant performance inputs, we have developed and implemented an LP preprocessor. This preprocessor automatically generates and stores in the LP database the usage of equipment and utilities, the product yields, and the product properties for six process units at Sun Petroleum Products Company s Toledo Refinery. Linked to the preprocessor are three already existing process simulators a fluid catalytic cracker or FCC simulator, a hydrocracker simulator, and a catalytic reformer simulator. 

The reformer simulator was converted to subroutine form for inclusion in nonlinear programming models of two refinery complexes. To save computer time and memory, the subroutine uses a linearized version of the original kinetic model, with 28 components and 33 reactions. Instead of numerical integration, the linearized model is solved analytically at constant temperature, pressure, and total mols using special subroutines to find the eigenvalues and eigenvectors of the reaction rate constant matrix. 

The reformer simulator also requires a description of the feed in terms of hydrocarbon components. These are shown in Table II. Fortunately, most of these components are measured in the crude assay and are predicted by the hydrocracker simulator. 

To speed the operation of the preprocessor, the convergence loops in the linked reformer simulator have been modified. In the inner loop, after a certain number of iterations, the mole fractions of C4 and heavier in the recycle gas are held constant. It was found that slight variations in these components (which are assumed to react in the reforming kinetic model) slowed down the rate of convergence without materially improving the accuracy of the results. 

Figure 6.2.32 Evolution of methane conversion ( Ht). mean radial process gas temperature and external and internal tube skin temperatures (Tprocessi and Tint), and total pressure in a tube of a steam reformer simulations by a one-dimensional reactor model (Section 4.10.7.3), internal/external tube diameter 10.2/13.2cm, heated tube length 11.1m, ring-shaped catalyst (height 1 cm, diameters 0.8 and 1.7cm), molar steam to methane ratio 3.4, average flue gas temperature 1100°C [data from Xu and Froment (1989a, b) Plehiers and Froment (1989)].

A fired tube reactor was configured to match the dimensions and catalyst loading of an existing oxo-alcohol synthesis gas steam reformer. Simulation results at observed conditions (feed gas composition, outlet temperature, steam to earbon ratio, ete.) agree very well with observed results. Catalyst activity is first determined by matching key effluent eomposition. 

Currendy, there are three commercially available PX adsorption processes UOP s Parex, IFP s Eluxyl, and Toray s Aromax (not to be confused with Chevron s Aromax process for reforming naphtha into aromatics). In all of these processes, the feed and desorbent inlets and the product oudet ports are moved around the bed, simulating a moving bed. 

Figure 2. Catalytic reforming flowsheet. (Used with permission of Simulation Sciences Inc.)...

The authors developed a multi-layered microreactor system with a methanol reforma- to supply hydrogen for a small proton exchange membrane fiiel cell (PEMFC) to be used as a power source for portable electronic devices [6]. The microreactor consists of four units (a methanol reformer with catalytic combustor, a carbon monoxide remover, and two vaporizers), and was designed using thermal simulations to establish the rppropriate temperature distribution for each reaction, as shown in Fig. 3. 

The catalyst (0.15 g) was loaded into a quartz tube reactor (internal diameter = 4 mm). The catalyst was pretreated in nitrogen at 400°C. Simulated gasoline reformate was used for the activity test of the catalyst. The composition of the simulated reformate was 36 wt% H2, 17 wt% CO2, 28 wt% N2, 17 wt% H2O, 1 wt% CO, and air was added additionally as the oxidant. The total flow rate was maintained at 100 ml/min. The test was performed over the temperature range of 120 280°C at various flow rates of inlet air. 

Dynamic Simulation of Plate-Type Reformer and Combustor System for Molten Carbonate Fuel Cell... 

Fig. 5. Result of reformer dynamic simulation with combustor feed rate change by 10% at 30 sec...

The experimental apparatus is consists of reformed gas feeding sections, CO PrOx reaction section in the reactor, and the analysis section with a gas chromatograph system. Simulated reformed gas composition was 75 vol.% H2, 24 vol.% CO2 and 1.0 vol.% CO. The dry reformed feed stream was fed with O2 (A.=l) into the microchannel reactor by MFC (Brooks 5850E). Water vapor (10vol.% of reformed gas) was also fed into the reactor by a s)ninge pump. 

Thus, the virtual heart may be used to simulate cardiac pathologies, their effect on the ECG, and the consequences of drug administration. It can be seen that drug discovery and assessment will be among the first fields where in silico technologies could reform research and development in a whole industry. 

Also a simulation of the flow field in the methanol-reforming reactor of Figure 2.21 by means of the finite-volume method shows that recirculation zones are formed in the flow distribution chamber (see Figure 2.22). One of the goals of the work focused on the development of a micro reformer was to design the flow manifold in such a way that the volume flows in the different reaction channels are approximately the same [113]. In spite of the recirculation zones found, for the chosen design a flow variation of about 2% between different channels was predicted from the CFD simulations. In the application under study a washcoat cata-... 

Yokota, O. et al., Steam reforming of methane by using a solar simulator controlled by H20/ CH4 = 1/1, Appl. Organomet. Chem., 14,867,2000. 

B. CFD Simulation of Reformer Tube Heat Transfer with... 

The overall effect of catalyst pellet geometry on heat transfer and reformer performance is shown in the simulation results presented in Table 1. The performance of the traditional Raschig ring (now infrequently used) and a modern 4-hole geometry is compared. The benefits of improved catalyst design in terms of tube wall temperature, methane conversion and pressure drop are self-evident. 

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