Steam methane reformer furnace

UNS S30409) stainless steel (SS) for metal temperatures above 1,200°F (650° C). Caustic stress corrosion cracking (SCC) from solids can occur in the steam preheat coils if solid carry-over is excessive (see Chapter One, Steam and Condensate section). The inlet connections to the steam methane reformer furnace tubes are either IViCr-V Mo (1,100°F [595°C] maximum) or 21/4Cr-1Mo (1,200°F [650°C] maximum). 

In early July 1947, Cities Service Corporation joined Kellogg s Synthol effort. Cities Service s refinery in Lake Charles, Louisiana, would operate an experimental steam-methane reforming furnace at 4.4 atmospheres. 

One advantage of partial oxidation is that significant reductions in NOx and C02 emission rates can be achieved compared to steam methane reforming. In one case a reduction of 20% was achieved when partial oxidation replaced steam methane reforming. This is because the point source emissions related to the furnace flue gas exhaust are not a part of this process. Emissions from partial oxidation processes are relatively small by comparison and primarily come from fired heaters that may be used to preheat the process feed177. 

For the process scenario discussed, the solar-thermal process avoids 277 MJ fossil fuel and 13.9 kg-equivalent C02/kg H2 produced as compared to conventional steam-methane reforming and furnace black processing. 

The cost of production for a steam methane reformer to produce 5 MMS-CFD of high purity hydrogen is shown in Table 4. This estimate is based on a cylindrical reformer furnace using a hydrogen PSA for hydrogen separation and purification. Capital cost is third-quarter 1996, US Gulf Coast [8]. 

The CALCOR process is similar to a conventional steam methane reformer with an amine acid gas removal system, except that the CO2 from the amine system is recycled to the reformer furnace. The reformer operates at a very low pressure to reduce reforming severity. The synthesis gas from the CO2 removal system is just above atmospheric pressure. It is saturated with water and residual CO2 and must be compressed before entering downstream separation equipment. The process features a very low methane slip below 500 ppm in the synthesis gas [11]. 

The maximum allowable superheat coil outlet temperature is 700°F to protect the carbon steel tubes from failure. At low steam generation rates, I have seen furnace firing rates and thus heater charge rates reduced to keep from overheating the steam above 700°F. If the steam is not used eventually to drive turbines, or as a reactant in a catalytic process (steam-methane reformer for or NHj production), then the heater capacity is being limited for no logical reason. 

A review of conventional hydrogen production via steam reforming is useful to appreciate the advantages of the POLYBED PSA system. The conventional system consists of a feed desulfurizer, reforming furnace, high-temperature and low-temperature shift converters, C02 removal system and a methanator (see Figure 2). 

Hydrogen, methanol, and ammonia plants are very similar. Methane or naphtha feed stock is first desulfurized and then combined with steam in a reformer furnace. Hydrogen and carbon dioxide are produced at 1,500° F (820° C) in the reformer as the starting point for all three processes. 

In an ammonia plant (Figure 4.2), the synthesis gas from the reformer furnace is fed into a secondary reformer vessel, where air is added through a burner to create outlet vessel temperatures of -1,800° F (980° C). The outlet of the secondary reformer vessel is cooled in a quench steam generator and sent to a shift converter this is followed by a carbon dioxide removal system such as the one in a hydrogen plant. The purified nitrogen from the air added in the secondary reformer vessel and hydrogen synthesis gas is fed to a methanator to convert residual oxides of carbon back to methane (which is inert in the ammonia conversion) the gas is then compressed to -3,000 psia (2,070 kPa). The compressed synthesis gas is fed to an ammonia converter vessel. As the synthesis gas passes over catalyst beds, ammonia is formed. The ammonia product is then cooled and refrigerated to separate out impurities. 

Description The gas feedstock is compressed (if required), desulfurized (1) and process steam is added. Process steam used is a combination of steam from the process condensate stripper and superheated medium pressure steam from the header. The mixture of natural gas and steam is preheated, prereformed (2) and sent to the tubular reformer (3). The prereformer uses waste heat from the flue-gas section of the tubular reformer for the reforming reaction, thus reducing the total load on the tubular reformer. Due to high outlet temperature, exit gas from the tubular reformer has a low concentration of methane, which is an inert in the synthesis. The synthesis gas obtainable with this technology typically contains surplus hydrogen, which will be used as fuel in the reformer furnace. If C02 is available, the synthesis gas composition can be adjusted, hereby minimizing the hydrogen surplus. Carbon dioxide can preferably be added downstream of the prereformer. 

The above reactions proceed also in the so-called rich-gas processes of British Gas and Lurgi/BASF, which convert naphtha with steam in autothermal reactions in a vessel filled with a special nickel-containing catalyst. It was formerly successfully used for town gas production from naphtha. This reaction may also used as pre-reformer ahead of a conventional tubular steam reforming furnace to convert higher hydrocarbons at low temperature and low S/C ratio into a methane reach gas which can than be reformed in the primary reformer with a standard methane reforming catalyst instead of an alkalized catalyst (Section 4.1.1.3.1). 

The PNP-3000 reactor plant was designed for the generation of process heat for a steam reformer (1071 MW) and of electricity with 540 °C / 19.5 MPa turbine steam (1929 MW). The helium coolant is heated up from 250 to 950 °C at a primary system pressure of 4 MPa. Nuclear power density is 5 MW/m. Four (or more) loops are connected to the reactor either one with circulator, steam generator plus two steam reformers. Eight steam reforming furnaces are to be operated at 825 °C with a methane conversion of about 65 % [69]. 

Hydrocarbons are converted into a mixture of hydrogen and oxides of carbon by reaction with steam over steam reforming catalysts. The reforming reaction is endothermic and the catalysts are packed into narrow tubes, which are heated in a furnace. The reforming furnace is commonly known as a reformer. An efficient methane steam reforming process was developed by 1936 and was first used on a large scale in North America during World War Two as shown in Ta-... 

Steam reforming refers to the endothermic, catalytic conversion of light hydrocarbons (methane to gasoline) in the presence of steam [see Eq. (5.1)]. The reforming reaction takes place across a nickel catalyst that is packed in tubes in an externally-fired, tubular furnace (the Primary Reformer). The lined chamber reactor is called the secondary reformer , and this is where hot process air is added to introduce nitrogen into the process. Typical reaction conditions in the Primary Reformer are 700°C to 830°C and 15 to 40 bar46. 

The feed is desulfurized and mixed with process steam before entering the steam reformer. This steam reformer is a top-fired box type furnace with a cold outlet header system developed by Krupp Uhde. The reforming reaction occurs over a nickel catalyst. Outlet reformed gas is a mixture of H2, CO, C02 and residual methane. It... 

Yokata, O., Oku, Y., Sano, T., Hasegawa, N., Matsunami, J., Tsuji, M., Tamura, Y. (2000). Stoichiometric consideration of steam reforming of methane on Ni/A1203 catalyst at 650°C by using a solar furnace simulator. Int. 1. Hydrogen Energy 25,81-86. 

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