Combined autothermal reformer

CAR [Combined autothermal reforming] A "reforming process for making "syngas from light hydrocarbons, in which the heat is provided by partial oxidation in a section of the reactor. Developed by Uhde and commercialized at an oil refinery at Strazske, Slovakia, in 1991. 

Heat exchange autothermal reforming, with a process gas heated steam reformer (heat exchange reformer) and a separate secondary reformer, or in a combined autothermal reformer, using excess or enriched air (under-stoichiometric or stoichiometric H/N ratio)... 

S. Fritsch, Synthesis Gas Production, Comparison of four Synthesis Gas Routes Steam Reforming, Combined Autothermal Reforming and Partial Oxidation , Krupp-Uhde Fertilizer Symposium 1998, Dortmund, June 11-13, 1998. 

Uhde has developed its Combined Autothermic Reformer (CAR) and has successfully operated a demonstration unit, which produces 13,000 m /h of process gas at 1.7 MPa [28]. CAR is a combination of reforming exchanger and r partial oxidation in a single vessel. The mixture of natural gas and steam is passed through the tubes filled with catalyst. These tubes are heated externally by hot reformed gas from the partial oxidation section. No commercial CAR unit has been installed as of late 1994. 

Combined Autothermal Reforming. In the combined autothermal reforming (CAR) process developed by Uhde (27), the HSR process and the ATR process are combinedin to one reactor (Fig. 3). 

Elimination of the reforming furnace is likely to be a significant trend in future ammonia plants. Similar technology is also under development by Uhde with their Combined Autothermal Reformer or although this process requires the... 

In more leoent ammonia plant designs, in which the large steam reforming furnace has been leplaeed with -heated reformers or combined autothermal reformers, the HTS eatalyst ean be leplaeed by a temperature resistant copper catalyst that can operate at temperature as low as 260°-270°C. 

Schematics of the reformer section of combined reforming of NG. 1 = Fired tubular reformer, 2 = furnace, and 3 = autothermal reformer.

ATR(l) [Autothermal reforming] A process for making CO-enriched syngas. It combines partial oxidation with adiabatic steam-reforming. Developed in the late 1950s for ammonia and methanol synthesis. Further developed in the 1990s by Haldor Topsoe. 

Fuel-reforming process should be understood in a broader sense as including all options such as partial oxidation (POX), steam reforming (SR), and their combination, i.e., autothermal reforming (ATR). In general, the fuel-reforming process can be represented by the following equation ... 

Today, different processes (steam reforming, autothermal reforming, partial oxidation, gasification) are available and commercially mature for hydrogen production from natural gas or coal. These processes would have to be combined with technologies for C02 capture and storage (CCS), to keep the emissions profile low. A power plant that combines electricity and hydrogen production can be more efficient than retrofitted C02 separation systems for conventional power plants. 

In addition to SMR, other technologies are used for syngas production from natural gas that involve addition of oxygen or air. The catalytic partial oxidation (CPO) reaction is given in Reaction (3) and in autothermal reforming (ATR) this reaction is combined with Reactions (1) and (2). 

The coupling of SR with POX is termed autothermal reforming (ATR). The exact definition varies. Some define ATR as an SR reaction and a POX reaction that take place over microscopic distances at the same catalytic site thus avoiding complex heat exchanging (16). Others have the less restrictive definition that ATR occurs when there is no wall between a combined SR reaction and catalytic POX reaction. ATR is carried out in the presence of a catalyst that controls the reaction pathways and thereby determines the relative extents of the POX and SR reactions. The SR reaction absorbs part of the heat generated by the POX process reaction, limiting the maximum temperature in the reactor. The net result is a slightly exothermic process. 

Autothermal Reforming is a combination of Steam Reforming and Partial Oxidation. In this example assume 47% nitrogen in the Synthesis Gas. 

The ATR (Autothermal Reforming) process makes CO-enriched syngas. It combines partial oxidation with adiabatic steam-reforming and is a cost-effective option when oxygen or enriched air is available. It was developed in the late 1950 s for ammonia and methanol synthesis, and then further developed in the 1990 s by Haldor Topspe2. The difference between Steam Methane Reforming (SMR) and ATR is in how heat is provided to activate the endothermic steam reforming reaction. In SMR, the catalyst is contained in tubes that are heated by an external burner. 

Fig. 1.20. Autothermal syngas generation by combining simultaneous autothermal reforming in an air/oxygen-fired fixed-bed reactor (ATR) and steam reforming in a gas-heated tubular fixed-bed reactor (GHR) [32, 33].

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