Reforming butane

Validation Case 3 (Primary Secondary Reformer Butane Feed Reconcile Case)... 

Rings Hydrocarbon steam reforming. Butane oxidation. 

Butanes are naturally occurring alkane hydrocarbons that are produced primarily in association with natural gas processing and certain refinery operations such as catalytic cracking and catalytic reforming. The term butanes includes the two stmctural isomers, / -butane [106-97-8] CH2CH2CH2CH2, and isobutane [79-28-9], (CH2)2CHCH2 (2-methylpropane). 

Butanes are recovered from raw natural gas and from petroleum refinery streams that result from catalytic cracking, catalytic reforming, and other refinery operations. The most common separation techniques are based on a vapor—Hquid, two-phase system by which Hquid butane is recovered from the feed gas. 

Naphtha at one time was a more popular feed, and alkah-promoted catalysts were developed specifically for use with it. As of 1994 the price of naphtha in most Western countries is too high for a reformer feed, and natural gas represents the best economical feedstock. However, where natural gas is not available, propane, butane, or naphtha is preferentially selected over fuel oil or coal. 

It can also be prepd by the catalytic reforming of other low-boiling hydrocarbons (ethane to butane) (Ref 3)... 

Figure 8.7 confirms that this is correct A single nickel catalyst used for steam reforming of n-butane deactivates steadily and gains weight due to the accumulation of carbon, but a Ni-Au catalyst maintains its reforming activity at a constant level [F. Besenbacher, I. ChorkendorfF, B.S. Clausen, B. Hammer, A.M. Molenbroek, J.K. Norskov and I. Stensgaard, Science 279 (1998) 1913]. 

Figure 8.7. Steam reforming of n-butane as a function of time for a conventional Ni catalyst and a novel Ni-Au alloy catalyst, showing the superior stability ofthe latter. [Adapted from...

Hydrogenolysis of butane was used to study the catalysis of the RhPt particles in mesoporous silica. This is a test reaction of reforming of alkanes in oil refinery, and methane, ethane, and propane are formed by the cleavage of terminal or central C-C bond (Scheme 1). 

Enciforming [National Chemical reforming] A petroleum reforming process that converts pyrolysis gasoline to mixtures of propane, butane, and aromatic hydrocarbons, thereby obviating the usual hydrogenation and solvent extraction processes. The catalyst is a ZSM-5-type zeolite containing both iron and a platinum metal. Developed by the National Chemical Laboratory, Pune, India, since 1988, but not yet commercialized. 

Hydrocarbon feedstocks for steam reformers include natural gas, refinery gas, propane, LPG and butane. Naphtha feedstocks with boiling points up to about 430°F can also be used. The ideal fuels for steam reformers are light hydrocarbons such as natural gas and refinery gas, although distillate fuels are also used. Residual fuels are not used since they contain metals that can damage reformer tubes. 

The modem gasolines are produced by blending products from cmde oil distillation, that is, fluid catalytic cracking, hydrocraking, reforming, coking, polymerization, isomerization, and alkylation.Two clear examples of the possible use of solid-acid catalysts in refining processes are the isomerization of lineal alkanes and the alkylation of isobutene with butanes. In both these cases, and due to the octane... 

In addition to natural gas, steam reformers can be used on light hydrocarbons such as butane and propane and on naphtha with a special catalyst. Steam reforming reactions are highly endothermic and need a significant heat source. Often the residual fuel exiting the fuel cell is burned to supply this requirement. Fuels are typically reformed at temperatures of 760 to 980°C (1,400 to 1,800°F). 

Downstream of the reactors and the hydrogen separator, the product is fed to one or more fractionating columns, where it is split into several streams. If just the butanes and lighter gases are removed, the remaining stream is generally called reformate. But in those refineries where benzene is recovered, to... 

An alternative approach for the utilization of biomass resources for energy applications is the production of dean-buming liquid fuels. In this respect, current technologies to produce liquid fuels from biomass are typically multi-step and energy-intensive processes. Aqueous phase reforming of sorbitol can be tailored to produce selectively a clean stream of heavier alkanes consisting primarily of butane, pentane and hexane. The conversion of sorbitol to alkanes plus CO2 and water is an exothermic process that retains approximately 95% of the heating value and only 30% of the mass of the biomass-derived reactant [278]. 

Temperature drop throughout the process requires the constant addition of heat. In reforming processes utilizing more than one reactor, the temperature drop in the last reactor is less severe. The final liquid reformate is separated from the produced hydrogen in a separation drum. Butane is then removed from the reformate by fractionation. 

Fig. 5. Conversion of n-butane as a function of time-on-stream during steam reforming in a flow reactor. The gray curve shows the conversion of the pure nickel catalyst, and the black curve represents the gold/nickel catalyst. From Reference (79).

Typical effects of pressure on dry gas, butane, C5+ liquid, and hydrogen production are shown in Figures 2 and 3 for the reforming of a... 

To produce the maximum yield of finished gasoline in a hydrocracker-reformer combination, the hydrocracker should be operated to give maximum liquid yields, followed by a modem low pressure catalytic reformer to give the desired octane improvement (6). More severe hydrocracker operation produces higher octane naphtha but leads to an increase in the production of butanes with reduced yields of finished... 

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