Steam hydrocarbon reforming reformer design

Many refiners are still operating hydrogen plants that were designed and built 20 or more years ago. These older plants were generally designed with the best available technology of the time. These typical plants consist of a steam-methane reformer (SMR) to convert the hydrocarbon feed to a S5mgas... 

Most industrial hydrogen is manufactured by the following hydrocarbon-based oxidative processes steam reforming of light hydrocarbons (e.g., NG and naphtha), POx of heavy oil fractions, and ATR. Each of these technological approaches has numerous modifications depending on the type of feedstock, reactor design, heat input options, by-product treatment,... 

Ce02-supported noble-metal catalysts such as Pt, Pd and Rh are of interest because of their importance in the so-called three-way converter catalysts (TWC), designed to reduce emissions of CO, NOx and uncombusted hydrocarbons in the environment and to purify vehicle-exhaust emissions. Such catalysts are also of current interest in steam reforming of methane and other hydrocarbons. Conventional practical catalysts for steam reforming consist of nickel supported on a ceramic carrier with a low surface area and are used at high temperatures of 900 C. This catalyst suffers from coke formation which suppresses the intrinsic catalyst activity. Promoters such as Mo are added to suppress coke formation. Recently, Inui etal(l991) have developed a novel Ni-based composite... 

The necessary fuel processing of natural gas or other hydrocarbons and coal before its use in the SOFC changes the system design. The following investigations have been done for methane as the main component of natural gas to keep the calculations simple. A common type of fuel processing for hydrocarbons is the endothermic steam reforming process as shown for methane in Equation (2.105) with the heat demand Equation (2.106)... 

T. Johansen, K.S. Raghuraman and L.A. Hacket, Trends in Hydrogen Plant Design - Steam Reforming will Continue to be the Main Source of H2 , Hydrocarbon Processing, [8] 119-27 (1992). 

Tindall, B.M. and King, D. L., 1994, Designing steam reformers for hydrogen production, Hydrocarbon Processing, 7, p69. 

Another advantage is that a prereformer may be preferred in flowsheets for processing heavier feedstocks. The prereformer converts heavier hydrocarbons to methane before they are fed to the steam reformer. This allows the steam reformer to be designed for methane service. The prereforming catalysts are very sensitive to poisons. Therefore a good feed purification section is essential.70... 

Description Natural gas or another hydrocarbon feedstock is compressed (if required), desulfurized, mixed with steam and then converted into synthesis gas. The reforming section comprises a prereformer (optional, but gives particular benefits when the feedstock is higher hydrocarbons or naphtha), a fired tubular reformer and a secondary reformer, where process air is added. The amount of air is adjusted to obtain an H2/N2 ratio of 3.0 as required by the ammonia synthesis reaction. The tubular steam reformer is Topsoe s proprietary side-wall-fired design. After the reforming section, the synthesis gas undergoes high- and low-temperature shift conversion, carbon dioxide removal and methanation. 

Autothermal reforming combines partial oxidation and adiabatic steam reforming for conversion of the hydrocarbon feedstock into synthesis gas free of soot and higher hydrocarbons. The ATR reactor design consists of burner, combustion chamber, and catalyst bed placed in a refractory lined vessel, as illustrated in Fig. 10. The hydrocarbon feedstock with steam is reacted with oxygen in a substoichiometric flame, often... 

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