Rhenium catalytic reforming

Rheniforming [Rhenium reforming] A catalytic reforming process developed by Chevron Research Company. The catalyst formulation includes rhenium. First announced in 1967 and first commercialized in 1970 by 1988, 73 units had been licensed. 

Ultraforming A catalytic reforming process developed by Standard Oil of Indiana and licensed by Amoco Oil Company. The catalyst contains platinum and rhenium, contained in a swing reactor - one that can be isolated from the rest of the equipment so that the catalyst can be regenerated while the unit is operating. The first unit was commissioned in 1954. 

In the catalytic reforming of naphthas there are a number of nonhydrocarbon materials which play an important part in the performance of the catalyst. Sulfur is a poison for the reforming catalyst. There appears to be evidence developing that the platinum-rhenium catalysts may be more sensitive to sulfur than the conventional catalysts. Effective pretreatment of the feed stock to maintain sulfur at low levels is desirable. 

Rhenium Catalysts A Major New Catalytic Reforming Development, API, Div. Ref., Midyear Meetg., 34th, Chicago (May 1969). 

A typical process flow diagram of a catalytic reformer is shown in Figure 3.17. Desulfurized naphtha is heated in feed-effluent exchangers and then passed to a fired heater, where it is heated to 850 to 1,000° F (455 to 540° C) at 500 psia (3,450 kPa) in a series of reactors and fired heaters. In the reactors, the hydrocarbon and hydrogen are passed over a catalyst (often platinum/rhenium based) to produce rearranged molecules, which are primarily aromatics with some isoparaffins. The reactor effluent is cooled by exchange and then passed to a separator vessel. The gas from the separator is recycled to the reactors. The liquid is fed to a fractionator. 

Poisoning of metal catalysts may provide a tool for improving selec> tivity by affecting the concentrations of ensembles required by different reaction paths. This is illustrated by steam reforming on sulfur passivated nickel catalysts and the results are compared with observations for sulfided platinum-rhenium catalysts for catalytic reforming and for a chlorine poisoned palladium catalyst for partial oxidation of methane. 

Another successful promotion is in catalytic reforming, where addition of rhenium to platinum leads to vastly improved performance, due to decreased hydrogenolysis of the hydrocarbons. " The rhenium functions perhaps as an electronic promoter, but its exact role is still being debated. Chemically, the rhenium prercremially bonds with low coordination sites on crystal plane corners, edges and steps. Since these atoms appear to be involved with the hydrogenolysis, coke-forming reactions are suppressed. ... 

Jacobson, R.L. Kluksdahl, H.E. McCoy, C.S. and Davis, R.W. "Platinum-rhenium catalysts a major new catalytic reforming development." Proceedings of the American Petroleum Institute, Division of Refining. 49 504-521 1969. 

Reforming Catalytic reforming is the process of increasing the number of double bonds on a petroleum product but maintaining the same number of carbon atoms. This process is done at high temperatures in the presence of a platinum or rhenium catalyst on alumina [1],... 

Catalytic reforming catalysts contain highly dispersed platinum (Pt), the activity of which is inhibited by sulfur. Therefore, an upstream hydrotreater lowers the sulfur content of reformer feeds to <1 wppm. In addition to Pt, modem multi-metallic catalysts contain highly dispersed rhenium (Re) and in some cases tin (Sn). 

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