Reforming, thermal

Thermal reforming Thermal sensitization Thermal stability Thermal transfer Thermal-transfer printing Thermal treatment Thermal wave imaging Thermate Thermate-TH2 Thermate-TH3 Therm-Chek... 

The initial process for molecular conversion was thermal reforming (late 1920s). Thermal reforming at 950 - 1050 F and 600 psi produced gasolines of 70 to 80 octane and heavy naphthas less than 40 octane. Products were olefins, diolefins, and aromatic compounds that were unstable in storage and tended to form heavy polymers and gums, which caused combustion problems. 

By 1950 a reforming process was introduced using a catalyst to improve the yield loline components while minimizing the formation of unwanted material. In catalytic as in thermal reforming, a naphtha-type material serves as the feedstock, but the reactions are carried out in the presence of... 

Recently, more sophisticated reactors, such as the auto thermal reformer, use a burner at the reactor entrance to heat the catalyst bed directly through combustion... 

SMR—steam methane reformer ATR—auto thermal reformer POX—partial oxidation PSA—pressure swing adsorption... 

Avaro [Aviation aromatics] A process for increasing the aromatics content of gasoline by thermal reforming in the presence of low molecular weight hydrocarbons. Used at the Shell refinery in Curacao during World War II. 

IFC conducted testing of a 100 kW mobile electric power plant (MEP) with the logistic fuels of JP-8 and DF-2. An auto-thermal reformer that achieved 98% conversion was used to convert the logistic fuel to a methane rich fuel. 

Reforming Both thermal and catalytic processes are utilized to convert naphtha fractions into high-octane aromatic compounds. Thermal reforming is utilized to convert heavy naphthas into gasoline-quality aromatics. Catalytic reforming is utilized to convert straight-run naphtha fractions into aromatics. Catalysts utilized include oxides of aluminum, chromium, cobalt, and molybdenum as well as platinum-based catalysts. 

Table 1. Laboratory Results of Thermal Reforming 248/396° F. East Texas Virgin Heavy Naphtha at 1000 Pounds per Square Inch ...

Figure 1. Thermal Reforming vs. Hydroforming of East Texas Virgin Heavy Naphtha...

Considerable development work has been and is now being carried out by many organizations to improve or replace the original catalyst as well as the component parts of the hydroforming unit itself. This paper describes a new and improved hydroforming process, which permits continuous operation through the use of a powdered or fluid catalyst. The new process is compared with thermal reforming and with the intermittent or cyclic fixed-bed process employed in the commercial plants mentioned above. 

In the middle thirties the reactions of naphtha and certain compounds known to be present in naphtha were being studied in university and industrial laboratories. One of the problems was to find a catalyst that was capable of synthesizing an aromatic from a paraffin. It was reasoned that the hydrogenation-dehydrogenation oxide-type catalysts such as molybdenum oxide and chromium might possess suitable activity at temperatures well below those employed in thermal reforming. 

Table II. Yield Comparison of Conventional Fixed-Bed Hydroforming with Thermal Reforming Plus Catalytic Polymerization...

Process Hydroforming Thermal reforming Hydroforming Thermal reforming... 

The economics of the fluid catalyst process represent a considerable improvement over the conventional fixed-bed process. This is attributed to reduced investment and operating costs in addition to the improved yield picture. The investment cost now visualized is very nearly the same as that for the thermal reforming plus catalytic polymerization combination mentioned previously. Consequently, the pay-out times are now shorter than for that process in high or low fuel cost areas. 

A comparison has been made of Platforming and of thermal reforming from the standpoint of yield-octane number relationships, product properties, hydrocarbon types, and with respect to the nature of chemical reactions responsible for improvement of octane number. Comparison is based on studies of thermal reforming in a commercial operation at a Pennsylvania refinery and in a pilot plant on a midcontinent naphtha and in pilot plants and laboratory Platforming on the same stocks. 

Correlations presented in the middle thirties enabled the prediction of octane number improvement resulting from thermal reforming (7, 21). They have continued to appear in the literature (6, 20). Improvement of the octane number of naphthas has been the principal function of thermal reforming, but Egloff (8) discusses its usefulness also for the production of light olefins which provide feed stocks for alkylation or polymerization processes. To show the distinct improvement in the yield-octane relationship realized by the catalytic polymerization of C3 and C4 olefins produced by thermal reforming, Mase and Turner (16) present experimental data at various reforming severities for two naphthas. 

HAENSEL AND STERBA— COMPARISON OF PLATFORMING AND THERMAL REFORMING... 

---