Phillips’ STAR process

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. 

Dunn, R.O. Brinkmeyer, F.M. Schuette, G.F. The Phillips STAR process for the dehydrogenation of C3, C4, and C5 paraffins, NPRA Annual Meeting, National Petroleum Refiners Association (NPRA) New Orleans, LA, Mar 22-24, 1992. 

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... 

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). 

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. 

Another cyclical process is the Phillips STAR pro-cess.t ] It uses a fixed-bed fired-tube reactor operating at a positive superatmospheric pressure. In many respeets, it is similar in design to a steam reforming furnaee with the heat of reaction provided by firing outside the tubes, thus operating at near-isothermal conditions. Steam is used as a diluent to lower the partial pressure of the reactants and, thus, to achieve reasonable conversion levels of about 30-40% for propane and 45-55% for butanes. It also helps slow down the deposition of carbon (coke) on the eatalyst, thereby extending cycle time from minutes to hours. 

Phillips Petroleum Star Process, Hydrocarbon Processing, June (1976) 133. Linde Process, Chem. Eng. News, March, 1992 Hydrocarbon Processing, July (2000). 

STAR [Steam Active Re-forming] A catalytic reforming process for converting aliphatic hydrocarbons to olefins or aromatic hydrocarbons. Hydrocarbons containing five or fewer carbon atoms are converted to olefins. Those containing six or more are dehydrocy-clized to aromatic hydrocarbons. The reactions take place in the vapor phase, in a fixed catalyst bed containing a noble metal catalyst, in the presence of steam. Demonstrated on a semi-commercial scale and offered for license by Phillips Petroleum Company. The first commercial plant was built for Coastal Chemicals in Cheyenne, WY, in 1992 another for Polibutenos Argentinos in 1996. 

The dehydrogenation process was first commercialized in the 1940 s (Houdry s CATADIENE). The initial catalyst used was chromia on alumina. Most commercial process still use this catalyst today. However, two recent processes use Pt on alumina catalyst (UOP s OLEFLEX) (Pujado, 1990) or other noble metals Phillip s STAR) (Brinkmeyer et al, 1983). 

The old Houdry process has been developed by UCI/Lununus to become the Catofin process while Phillips and UOP have introduced their Star and Ole-flex processes. Linde in Germany has also introduced a process. A range of dif-... 

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