Dehydrogenation of butane, catalytic

Butadiene is obtained mainly as a coproduct with other light olefins from steam cracking units for ethylene production. Other sources of butadiene are the catalytic dehydrogenation of butanes and butenes, and dehydration of 1,4-butanediol. Butadiene is a colorless gas with a mild aromatic odor. Its specific gravity is 0.6211 at 20°C and its boiling temperature is -4.4°C. The U.S. production of butadiene reached 4.1 billion pounds in 1997 and it was the 36th highest-volume chemical. ... 

Butadiene could also be produced by the catalytic dehydrogenation of butanes or a butane/butene mixture. 

Paraffin dehydrogenation for the production of olefins has been in use since the late 1930s. During World War II, catalytic dehydrogenation of butanes over a chro-mia-alumina catalyst was done for the production of butenes that were then dimerized to octenes and hydrogenated to octanes to yield high-octane aviation fuel. 

Butadiene, the simplest of the conjugated dienes, is produced commercially by thermal cracking of petroleum fractions and catalytic dehydrogenation of butane and butene. Polymerization of butadiene can potentially lead to three poly(l,2-butadiene)s, atactic, isotactic, and syndiotactic, and two cis and irons forms of poly(l,4-butadiene). This is discussed in Chapters 2 and 3. 

The catalytic dehydrogenation of butane is important both in the manufacture of butadiene and as one step in the synthetic manufacture of gasoline. It has been reported that the principal reaction and important secondary reaction are as follows ... 

Series reaction networks are not limited to two reactions. Butadiene (C4H6) is an important monomer that goes into a large number of elastomeric products, including automobile tires. Butadiene can be produced by the catalytic dehydrogenation of butane (C4H10) as shown below. 

Dehydrogenation. Dehydrogenation of / -butane was once used to make 1,3-butadiene, a precursor for synthetic mbber. There are currently no on-purpose butadiene plants operating in the United States butadiene is usually obtained as a by-product from catalytic cracking units. 

Butadiene. Although butadiene was produced in the United States in the eady 1920s, it was not until the start of Wodd War 11 that significant quantities were produced to meet the war effort. A number of processes were investigated as part of the American Synthetic Rubber Program. Catalytic dehydrogenation of / -butenes and / -butanes (Houdry process) and thermal cracking of petroleum hydrocarbons were chosen (12). 

During World War II, production of butadiene (qv) from ethanol was of great importance. About 60% of the butadiene produced in the United States during that time was obtained by a two-step process utilizing a 3 1 mixture of ethanol and acetaldehyde at atmospheric pressure and a catalyst of tantalum oxide and siHca gel at 325—350°C (393—397). Extensive catalytic studies were reported (398—401) including a fluidized process (402). However, because of later developments in the manufacture of butadiene by the dehydrogenation of butane and butenes, and by naphtha cracking, the use of ethanol as a raw material for this purpose has all but disappeared. 

During World War II, the Japanese cut ofFU.S. access to sources of natural rubber, giving the Americans a strategic imperative to develop and expand the manufacture of synthetic rubber. The C4 streams in refineries were a direct source of butadiene, the primary synthetic rubber feedstock. As a coincidence, the availability of this stream was growing rapidly with the expansion of catalytic cracking to meet wartime gasoline needs. Additional butadiene was manufactured by dehydrogenation of butane and butylene also. 

Butadiene (> 98%w/w) 20 ooo longtons Catalytic dehydrogenation of n-butenes feedstock of liquid mixed hydrocarbon stream containing 80.5 mol % n-butenes, 11.5 mol % n-butane, and 1 mol % of higher hydrocarbons. 

Spectra of AgHf2(PC>4)3 during dehydration and dehydrogenation of butan-2-ol were recorded by Brik et al. (2001), who used the Harrick accessory to determine the state of silver. The authors reported slightly lower conversions in the cell than in a U-shaped microreactor. The catalytic data corresponding to the spectra are not shown in the paper. 

The dehydrogenation process feed can be refinery streams from the catalytic cracking processes. This mixed C4 stream typically contains less than 20 percent n-butenes. For use in dehydrogenation, however, it should be concentrated to 80-95 percent. The isobutylene generally is removed first by a selective extraction-hydration process. The n-butenes in the raffinate are then separated from the butanes by an extractive distillation. The catalytic dehydrogenation of n-butenes to 1,3-butadiene is carried out in the presence of steam at high temperature (>600°C) and... 

Manufacturing processes today employ petroleum raw materials. In Europe and Japan, butadiene is obtained entirely by extraction from steam C4 cuts (see Se on 3.1.2). In the United States, it is also produced by the dehydrogenation of butane and particularly of butenes contained in C4. cuts from catalytic cracking. 

Supported vanadium catalysts, whereby vanadium oxide is dispersed on a support such as alumina or titania are of particular importance in, for instance, the oxidative dehydrogenation of alkanes [58-64]. Such materials have attracted considerable interest in the direct dehydrogenation of butane, where a key driver is to identify the relationship between catalytic activity and structural properties [5, 6, 65-68]. In the pure (solid) metal oxides the coordination of vanadium is well defined. However, this is not necessarily true in the case of supported catalysts. Vanadium may be present on the support surface as isolated vanadium ions dimeric or polymeric species one- and two-dimensional chains of vanadium ions ... 

For those reactions such as dehydrogenation of butane or isobutanc which require frequent regeneration of the catalyst or catalytic membrane, a cyclic process involving reaction and coke-bumout steps in sequence may need to be considered. It is essential, however, that a purge step be installed between the reaction and the burnout steps to... 

Butadiene (1,3-butadiene) is manufactured in the petroleum industry by the catalytic dehydrogenation of the butanes and butenes, and by the direct cracking of naphthas and light oils. The overall butadiene yield by catalytic dehydrogenation, the most common industrial process, is as high as about 80% at selectivities of about 90%. The yields and selectivities of butadiene by... 

Derivation (1) Catalytic dehydrogenation of butenes or butane (2) oxidative dehydrogenation of butenes. 

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