Starring process

The Phillips Steam Active Reforming (STAR) process catalyticaHy converts isobutane to isobutylene. The reaction is carried out with steam in tubes that are packed with catalyst and located in a furnace. The catalyst is a soHd, particulate noble metal. The presence of steam diluent reduces the partial pressure of the hydrocarbons and hydrogen present, thus shifting the equHibrium conditions for this system toward greater conversions. 

The H-Oil and T-STAR processes are jointly licensed by Texaco and HRI, Inc. 2Acronym for Texaco Strategic Total Activity Retention. 

Johns, W. F., Clausen, G., Nongbri, G., and Kaufman, H., Texaco T-STAR Process for Ebullated Bed Hydrotreating/Hydrocracking, paper presented at the 1993 National Petroleum Refiners Association Annual Meeting, San Antonio, TX (1993)... 

Application The Uhde Sleam Active Reforming STAR process produces (a) propylene as feedstock for polypropylene, propylene oxide, cumene, acrylonitrile or other propylene derivatives, and (b) butylenes as feedstock for methyl tertiary butyl ether (MTBE), alkylate, isooctane, polybutylenes or other butylene derivatives. 

Commercial plants Two commercial plants using the STAR process for dehydrogenation of isobutane to isobutylene have been commissioned (in the US and Argentina). More than 60 Uhde reformers and 25 Uhde secondary reformers have been constructed worldwide. 

From now on, butane can be dehydrogenated by a new technique caQed the Star process, already mentioned in the case of propane dehydrogenation (see Section 23.4.2) and also in that of isobutene manufoctnre (see Secticm 63). 

In the STAR process (steam active reforming) feed is heated and mixed with steam before passing to the reactor. This avoids the use of pumping to lower the partial pressure of the reactants. The outline of the process is shown in Figure 10.5. ... 

R.D. Dunn et al.. The Phillips steam active reforming (STAR) process for the dehydrogenation of C3, C4 and C5 paraffins. Presented at the 1992 NPRA meeting. New Orleans, LA, March 22-24,1992. 

The Phillips STAR process also regenerates the catalyst on a cyclic basis, but while the Houdry regeneration is actually a mechanism to provide the heat for the reaction even when coke buildup is still very low, the catalyst in the isothermal STAR process is only regenerated after coke has accumulated to appreciable levels that result in low catalyst activity. 

Periodic catalyst regeneration or carbon burn off is required to maintain the activity of the catalyst. Typical cycle time is reported to be at least 8 hr, with 7 hr of process time and 1 hr of regeneration time. For continuous operation, various furnace modules can be operated such that, for example, seven operate in the process mode while one is in the regeneration mode. Fig. 13 shows a schematic diagram of a STAR process unit. ... 

Several commercial processes have been developed for the catalytic dehydrogenation of propane to propylene as presented in Table 4. Of the seven commercial propane dehydrogenation plants in operation, six use UOP s Oleflex continuous moving-bed process. The other uses ABB Lummus Catofin cyclic multiple-reactor system. Other processes include Krupp Uhde s STAR process, as well as technologies from Linde and Snamprogetti. ... 

Figure 3.35 shows a process flow diagram of Phillips MTBE/ETBE/TAME process. This process is often called the Phillips Etherification Process. The reaction section (1,2) which receives methanol and isobutene concentrate, contains an ion exchange resin. The isobutene concentrate may be mixed olefins from a Fluid Catalytic Cracking Unit (FCCU) or steam cracker or from the on-purpose dehydration of isobutene (Phillips STAR process). High purity MTBE (99 wt%) is removed as a bottoms product from the MTBE fractionator (3). AH of the unreacted methanol is taken overhead, sent to a methanol... 

The starring process" applied (a) successfully to naphthalene, (b) unsuccessfully to... 

The STAR process is also performed in fixed beds, over noble metal (Pt) supported by zinc and calcium aluminate and impregnated with various metals, but it is an ODH process. The catalyst maintains its activity for DH and is stable in the presence of steam and oxygen. The STAR process was proven for several applications, among them ODH of propane to propylene and ODH of butanes. 

Johns WF, Clausen GA, Nongbri G, Kaufman H. Texaco T-star process for ebullated bed hydrotreating/hydro-cracking. National Petroleum Refiners Association (NPRA) Conference, San Antonio, TX, 1993. 

Phillips STAR process uses a tubular reactor to supply the heat of the reaction in a fired fiirnace. Steam is used to lower the partial pressure of the butanes (and thus increase the equilibrium conversion) and reduce coking. The STAR process operates on about an 8 hour cycle before regeneration (Brinkmeyer, et al, 1983). 

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