Reforming concept

Gas-Heated Reforming. Gas-heated reforming is an extension of the combined reforming concept where the primary reformer is replaced by a heat-transfer device in which heat for the primary reforming reaction is recovered from the secondary reformer effluent. Various mechanical designs have been proposed which are variants of a shell-and-tube heat exchanger (12,13). 

Ammonia Plant 1. Where possible, use natural gas as the feedstock for the ammonia plant, to minimize air emissions. 2. Use hot process gas from the secondary reformer to heat the primary reformer tubes (the exchanger-reformer concept), thus reducing the need for natural gas. 

Emission-Free Reformer Concept for Portable Power Applications... 

Fig. 2.2. Reforming concepts for high-temperature fuel cells.

A tool is required for the evaluation of possible combinations of different reforming concepts, and for the analysis of various flow sheet options such as gas recycling, cell cascading, and side feeding. This tool should be ... 

As indicated in Fig. 2.2, three different reforming concepts are available for high-temperature fuel cells. The steady-state anode model presented above allows a comparison of various combinations of reforming concepts. First, a system without a reforming catalyst inside the anode channel is considered - that is, a fuel cell without DIR. Three alternatives for fuel gas treatment are discussed ... 

In this chapter, three applications of this model are demonstrated. The comparison of different reforming concepts reveals the advantages of direct internal reforming (DIR) in the anode channel of the fuel cell. Moreover, with the help of the proposed model, the benefit of fuel cell cascades can be demonstrated and they can be compared to single cells. Results indicate that a considerable power increase can be expected, but the additional hardware required might offset any benefit in the case of smaller systems. The third application demonstrates that anode gas recycle can be simulated with this model, but it also reveals its limitations, as temperature effects are not considered. 

Cyrogenic methods are usually used for final purification of partial oxidation gases, but may be also incorporated in steam reforming plants. A prominent example for the application in a steam reforming concept is the Braun Purifier process [746]-[753]. 

The first generation of the single-train steam reforming plants is discussed in [426], [1007]-[1012], and the required catalysts are reviewed in [633], [1013] -[1014], A survey of the development of the steam reforming concept through 1972 can be found in [1015]. Other references which cover the development of the steam reforming before the introduction of the single-train concept (1940 to 1960) can be found in [402 p. 276]. 

Peters, R. Dusterwald, H.G. Hohlein, B. Investigation of a methanol reformer concept considering the particular impact of dynamics and long-term stability for use in a fuel-cell-powered passenger car. J. Power Sources 2000, 86 (1-2), 507-514. 

If the module is equal to 2.0, the gas contains just the stoichiometric amount of hydrogen for MeOH production. A module lower than 2 indicates a deficiency in hydrogen, and a value higher than 2 reflects a surplus of hydrogen. The two-stage reforming concept enables the production of a synthesis gas with the desired module. 

Advanced Reforming Technology. The advanced reforming technology (ART) reformer concept (31) developed by KTI SpA (now Technip) is a convective reformer and is characterized by utilizing up to the maximum extent of the waste heat available in the steam-reforming process for the process itself and not for the production of export steam. This results in a reduced operating and investment costs. 

Figure 3.12 A convective reformer concept. Udengaard ef a/. [502]. A burner in the centre tube and flue gas are cooled by two concentric catalyst beds with internal heat exchange to cool the product gas.

The membrane reformer concept is shown in Eigure 5.55. Basically, the concept is fairly similar to the conventional concept described above. The most striking... 

Figure6.10 Plate reformer concept for stationary applications [5].

Figure 9.26 Schematic principle of the FLOX reformer concept [16]...

Fuel cell developers have for many years known that the heat required to sustain the endothermic reforming of low molecular weight hydrocarbons (e.g. natural gas) can be provided by the electrochemical reaction in the stack. This has led to various elegant internal reforming concepts that have been applied to the molten carbonate or solid oxide fuel cells, on account of their high operating temperatures. 

Figure 8.8 Plate reformer concept. Catalyst is coated as a thin film onto one or both sides of a heat exchanger material.

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