Propane, products from

Table 1. Products from the Reaction of a Propane Air Mixture at Various Pressures, %...

Relatively small amounts of methane, ethane, and propane also are produced as by-products from petroleum processes, but these usually are consumed as process or chemical feedstock fuel within the refineries. Some propane is recovered and marketed as LPG. 

The bottoms, consisting of absorption oil, absorbed propane, and higher boiling hydrocarbons, are fed to the lean-oil fractionator. The LPG and the natural gas Hquids are removed as the overhead product from the absorption oil which is removed as a ketde-bottom product. 

The overhead product from the lean-oil fractionator, consisting of propane and heavier hydrocarbons, enters the depropanizer. The depropanizer overhead product is treated to remove sulfur and water to provide specification propane. The depropanizer bottoms, containing butane and higher boiling hydrocarbons, enters the debutanizer. Natural gasoHne is produced as a bottom product from the debutanizer. The debutanizer overhead product is mixed butanes, which are treated for removal of sulfur and water, then fed iato the butane spHtter. Isobutane is produced as an overhead product from the spHtter and / -butane is produced as a bottoms product. 

Fractionation. Direct fractionation also can be used to remove dissolved water from LPG. The water-rich overhead vapor from the dryer fractionator is returned to the fractionator as reflux and the water phase is discarded. A dry LPG product that meets either propane or butane water specifications is produced as a ketde product from the fractionator. 

Significant products from a typical steam cracker are ethylene, propylene, butadiene, and pyrolysis gasoline. Typical wt % yields for butylenes from a steam cracker for different feedstocks are ethane, 0.3 propane, 1.2 50% ethane/50% propane mixture, 0.8 butane, 2.8 hill-range naphtha, 7.3 light gas oil, 4.3. A typical steam cracking plant cracks a mixture of feedstocks that results in butylenes yields of about 1% to 4%. These yields can be increased by almost 50% if cracking severity is lowered to maximize propylene production instead of ethylene. 

The dephlegmator process recovers a substantially higher purity C2+ hydrocarbon product with 50—75% lower methane content than the conventional partial condensation process. The C2+ product from the cryogenic separation process can be compressed and further separated in a de-ethanizer column to provide a high purity C3+ (LPG) product and a mixed ethylene—ethane product with 10—15% methane. Additional refrigeration for the deethanization process can be provided by a package Freon, propane or propylene refrigeration system. 

The propylene-90 bottoms product from the deethanizer may be upgraded to high polymer grade 99.8% purity by superfractionation. Propane bottoms are used elsewhere in the refinery. 

It is not necessary that the intermediate be separated from the reaction medium in the preparation of the end product. Instead, the reaction mixture, after cooling, is treated with 200 ml of water acidified with 42 ml 10% hydrochloric acid solution, and filtered. To the clear, light yellow filtrate is added dropwise a solution of 9.B g (0.07 mol) 5-nltro-2-furaldehyde in 100 ml ethyl alcohol. An orange solution of the hydrochloride results. The free base is precipitated asyellow plates by making the solution basic with saturated sodium carbonate solution. 14 g of the compound is filtered off by suction, washed with alcohol, and dried. The yield, MP 204°C to 205°C (dec.), is 53% of theoretical based on 3-(N-morpholinyl)-1,2-epoxy-propane. Recrystallization from 95% alcohol (75% recovery) raises the melting point to 206°C (dec.). 

Note that in a high purity condition as is represented in this example, the system is quite sensitive to the overhead withdrawal rate (product from the system). This system is for the purification of propylene from a feed high in propyl lene, with lessor amounts of propane, butane, and ethane. 

A major use of propane recovered from natural gas is the production of light olefins by steam cracking processes. However, more chemicals can be obtained directly from propane by reaction with other reagents than from ethane. This may be attributed to the relatively higher reactivity of propane than ethane due to presence of two secondary hydrogens, which are easily substituted. 

Like propane, n-hutane is mainly obtained from natural gas liquids. It is also a hy-product from different refinery operations. Currently, the major use of n-hutane is to control the vapor pressure of product gasoline. Due to new regulations restricting the vapor pressure of gasolines, this use is expected to he substantially reduced. Surplus n-butane could be isomerized to isobutane, which is currently in high demand for producing isobutene. Isobutene is a precursor for methyl and ethyl tertiary butyl ethers, which are important octane number boosters. Another alternative outlet for surplus n-butane is its oxidation to maleic anhydride. Almost all new maleic anhydride processes are based on butane oxidation. 

What is the structure of the aldol product from propanal ... 

Urbanski and Sion (Ref 3) later prepd it in small quantities, together with 1-nitropropane, on treating n-propane vapor with gaseous nitrogen. More recently, Kisp ersky et al (Ref 5) prepd a product from 1,3-diiodopropane and Ag nitrate which was stable for at least 9 months Its Na compd, C3Hs(N02)2Na, was prepd by Keppler Meyer (Ref 2), and was reported to be a violent expl ( heftig explodierendes pulver in Ger)... 

On the other hand, the formation of ethylene was ascribed mainly to the unimolecular decomposition of a neutral excited propane molecule. These interpretations were later confirmed (4) by examining the effect of an applied electrical field on the neutral products in the radiolysis of propane. The yields of those products which were originally ascribed to ion-molecule reactions remained unchanged when the field strength was increased in the saturation current region while the yields of hydrocarbon products, which were ascribed to the decomposition of neutral excited propane molecules, increased several fold because of increased excitation by electron impact. In various recent radiolysis 14,17,18,34) and photoionization studies 26) of hydrocarbons, the origins of products from ion-molecule reactions or neutral excited molecule decompositions have been determined using the applied field technique. However, because of recent advances in vacuum ultraviolet photolysis and ion-molecule reaction kinetics, the technique used in the above studies has become somewhat superfluous. 

Various cyclic phosphonate esters 36 and 37 have been described previously as products from the HHT reaction of 25 with the appropriate cyclic phosphite. A complementary method has also been developed from the V-protected phosphonyl chloride 84, which was readily prepared from the corresponding phosphonic acid 83. Subsequent reaction of 84 with the appropriate diol produced the cyclic phosphonate esters 85 (63). Higher homologs of 85 have also been prepared from the analogous propane or butane diols. 

Product distribution for propane pyrolysis. [From Schutt, Chemical Engineering Progress, 50 (415), 1954. Used with permission.]... 

Bulk Plants, Distribution and Marketing Terminals store and distribute the finished products from the refineries and gas plants. Typically these facilities handle gasoline, diesel, jet fuels, asphalts, and compressed propane or butane. 

Liquefied petroleum gas (LPG) was used as fuel for the first time in the USA in 1912. Under the general term natural gas liquids (NGL), 60% of global LPG originates as a fraction separated from methane during the production of oil and gas the remaining 40% are generated as a by-product from the fractionated distillation of crude oil in refineries. Liquefied petroleum gas is a mixture of propane and butane, with the mixing ratio dependent on the country and season. 

A typical feature of hydroformylation is the fact that both sides of the double bond are in principle reactive, so only ethene yields propanal as a single product. From propene, two isomers are formed linear or normal butanal and 2-methylpropanal (branched or iso product). With longer chain 1-alkenes, the isomerization of the double bond to the thermodynamically more favored internal positions is possible, yielding the respective branched aldehydes (Fig. 1). Frequently, terminal hydroformylation is targeted because of the better biodegradability of the products. Thus, not only stability, activity, and chemoselectivity of the catalysts are important. A key parameter is also the regioselectivity, expressed by the n/i ratio or the linearity n/(n+i). 

Synthesis gas can easily be confused with the oxymoron synthetic natural gas, SNG. Both are sometimes called "syngas." But SNG is basically methane made from petroleum products, like naphtha or propane, or from coal. It s used as a substitute for or supplement to natural gas. 

Figure 7.7 Propane conversion percentage versus time (bottom), coke level versus temperature (top), and Raman spectra as coke level increases (inset). Coke level builds to a preset limit, after which a regeneration process is completed and propane production begins again. Reprinted from Bennici et al. (2007) [79]. Copyright Wiley-VCH Verlag CmbH Co. KCaA. Reproduced with permission.

Write structural formulas and names of four possible aldol condensation products from propanal and butanal. In each case, indicate which aldehyde acts as nucleophile and which as electrophile. 

Steam crackers provide the traditional cost-effective approach for olefins production from lighter feed stocks such ethane, propane, naphtha, and AGO. However, these options typically provide higher E/P ratio. To meet the increasing demands of ethylene and particularly propylene, refiners and petrochemical producers are planning integrated facilities. The objectives are ... 

Aartun, L, Silberova, B., Venvik, H., Pfeifer, P., Gbrke, 0., Schubert, K. and Holmen, A., Hydrogen Production from Propane in Rh-impregnated Metallic MicroChannel Reactors and Aumina Foams, Cat Tod., (2005) 105, 469-478 A. Fick, Phil. Mag. (1855), 10, 30 and W.F. Smith, Eoundations of Materials Science and Eng. 3 ed., McGraw Hill (2004)... 

Alkanes appear to react with platinum(IV) in an identical manner to benzene (34, 84) chloromethane and chloroethane can be detected as the reaction products from methane and ethane, respectively. When propane, butane, or hexane is the reactant, the terminal chloro isomers predominate over the internal isomers. This was interpreted to mean that primary C—H bonds are the most reactive (34), but a more detailed study has shown that this conclusion does not necessarily follow from the experimental results (84). When cyclohexane is the reactant, dehydrogenation (or chlorination and then dehydrohalogenation) occurs to give benzene as one of the reaction products (29, 34, 84). 

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