Gas heated reformer

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). 

Two processes of this kind are in operation, and some others are at the pilot stage. As of 1999, single train capacities have been limited to 1,000 tonnes per day or less53, and four plants had been installed that used this type of technology from Synetix. This type of reformer, referred to as a Gas Heated Reformer (GHR) is shown in Figure 5.1172. 

A Gas-Heated Reformer (which receives heat directly from the secondary reformer process gas),... 

The gas-heated reformer (GHR) reduces the need for the high pressure steam system associated with the primary reformer and also minimizes or eliminates nitrogen oxide formation. The GHR is discussed in more detail in Chapter 5. 

Farnell, P.W., Synetix s Advanced Gas Heated Reformer , AIChE Ammonia Safety Symposium, Seatde, WA, September, 1999. 

In this paragraph two of the most appropriate concepts for steam reforming employing a membrane will be discussed, namely Membrane Steam Reforming (MSR) and Gas Heated Reforming (GHR) with enriched air. The cases are described below, and are based on a Techno-Economic Evaluation prepared by KEMA, SINTEF and Norsk Hydro [21],... 

Another possible concept for membrane steam reforming is Gas Heated Reforming (GHR). A flowsheet of this process is provided in Figure 4. 

The mixed feed stream is given a final preheating to 430°C, and fed to the gas-heated reformer, where the feedstock is partially converted to synthesis gas by conventional membrane steam reforming (paragraph 5.1). The partially reformed gas leaves the gas-heated reformer and is fed to the secondary reformer together with enriched air and hence partially combusted. 

The product gas leaves the secondary reformer at a temperature of 885°C and is heat-exchanged in the primary membrane reformer. After that, the product gas leaving the gas-heated reformer is utilised for preheating of the natural gas feed, heating of circulating water in the saturator loop and generation of LP steam at 3 bar. Finally, after a temperature decrease to 265°C the gas is fed to a shift converter, after which again methanation takes place and removal of CO2 and traces of water. 

Fig. 22.5. Advanced Gas Heated Reformer (AGHR) from Synetix. (Reproduced by permission of Johnson Matthey Catalyst. Copyright Johnson Matthey PLC.)...

GHR [Gas Heated Reformer] A process for making syngas from natural gas, designed for making methanol. Developed by ICI, Davy, and Aka Kvaerner. See LCM. 

In the ICI gas-heated reformer (GHR) (Figure 49) the reformer tubes consist of an outer scabbard tube with an open ended bayonet tube inside, and the annular space between the tubes is filled with the reforming catalyst. The steam/natural gas mixture enters the tubes via a double tube sheet and flows downwards through the catalyst, and the reformed gas leaves through the bayonet tubes. To enhance the heat transfer from... 

Another type of steam-reforming reactor that is attracting increasing attention is known as gas heated reformers or heat exchange reformers. In such reformers, heat is transferred by convection and the heat source is a hot process gas from another reformer or a partial oxidation reactor. A number of different installations of heat exchange reformers can be envisaged. In Fig. 5, the installation of a heat exchange reformer either in series or in parallel to an auto-thermal reformer (ATR) is illustrated. 

The gas-heated reformer is a reformer reactor that can be integrated with a primary reformer or with an oxygen secondary reformer to improve overall plant efficiency. A schematic of the reactor is shown in Figure 7 [2]. The principle of its operation is to maximize the recovery of high and medium... 

The reforming exchanger concept totally eliminates the furnace and uses a hot secondary reformer outlet as its heat source. Surplus air over the stoichiometric demand or oxygen-enriched air in the secondary reformer is required to balance the heat demand for the primary reforming reaction. Chiyoda proposed this concept in 1984 [26,271 however, ICI was the first one. to comr mercialize a reformer exchanger called the Gas Heat Reformer (GHR) as part of their Leading Concept Ammonia (LCA) process. The GHR is discussed further under the LCA process section. 

Gas-Heated Reformer. The gas-heated reformer (GHR) concept (25,26) is another process, which uses the heat content present in the synthesis gas. 

Figure 2.35 Syngas for GTL. Gas heated reforming (HTER) in combination with autothermal reforming. Bakkeud et al. [34]. Reproduced with the permission of Elsevier.

At present, FT units are built with a carbon yield to C5+ products of 75% [477] corresponding to a CO2 emission of 1.1 tonnes/tonne C5+ product and a thermal efficiency of approximately 65% [193], The diesel product is sulphur-ffee and has a high cetane number (70+). This makes the GTL plant economically feasible at oil prices above 25-40 USD/b depending on location and gas price. There may be room for improvement of the thermal efficiency, for instance by adding gas heated reforming for heat recovery as illustrated in Figure 2.35. 

Hicks, T., A Decade of Gas Heated Reforming, FINDS, Volume XI, Number 3 Third Quarter 1996. 

In the development of the steam-reforming route to ammonia, for many years there has been a desire to eliminate the steam-reforming furnace for reasons of capital cost, efficiency, and reliability. This technology has now been demonstrated on a commercial scale by ICI with the LCA process. With this process the plant is simplified by the use of a Gas Heated Reformer (GHR) in which the primary reformer receives heat directly from the process gas leaving the secondary reformer. This compact pressurized reformer eliminates the massive furnace structure and the high-pressure steam system of a conventional plant. A pressure swing adsorption... 

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