Steam reforming industrial plants

In this section we collect some computed results when simulating industrial steam reformers. We compare the actual plant outputs with those obtained by simulation using the three models that we have developed earlier. We investigate both the close to thermodynamic equilibrium case and the far from thermodynamic equilibrium case. 

Of the indirect liquefaction procedures, methanol synthesis is the most straightforward and well developed [Eq. (6)]. Most methanol plants use natural gas (methane) as the feedstock and obtain the synthesis gas by the steam reforming of methane in a reaction that is the reverse of the methanation reaction in Eq. (5). However, the synthesis gas can also be obtained by coal gasification, and this has been and is practiced. In one modern low-pressure procedure developed by Imperial Chemical Industries (ICI), the synthesis gas is compressed to a pressure of from 5 to 10 MPa and, after heating, fed to the top of a fixed bed reactor containing a copper/zinc catalyst. The reactor temperature is maintained at 250 to 270°C by injecting... 

Today, the United States is using some 9 billion cubic feet of H2 a day in the petrochemical, food, and rocket propulsion industries. Around 98% of the bulk H2 is produced by steam reformation of natural gas (e.g., methane). Methane is reacted with water vapor over a catalyst to form carbon monoxide (CO) and H2. H2 can also be made from ethanol (alcohol), biomass, fossil fuels, or organic waste by the process of "reforming." Most of the currently operating H2 production plants depend on reforming natural gas. This is a process that emits C02 while consuming a nonrenewable fossil... 

These catalysts have to fulfil new safety requirements as they may be operated in the consumer s home, and also will experience a very different duty cycle than industrial catalysts. Another field that has attracted interest is sulfur tolerant shift catalysts. Catalysts have been developed for high sulfur concentrations in the feed gas since the 1960s, but have not found large-scale application up to the present. The fact is that most ammonia, methanol, and hydrogen plants are based on natural gas or naphtha feedstocks, which have relatively low content of sulfur-containing compounds, and therefore do not require these more expensive catalysts. HDS is typically used to reduce sulfur levels in the feed gas to ppm to ppb levels to protect the steam reforming and downstream catalysts. 

Studies point to the superiority of direct hydrogen, but this is regarded by some in the industry as less attractive than liquid fuels such as methanol. A large steam reformer plant could supply 1 million cars with hydrogen. 

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