Butane from ethane

Figure 1.4. Temperature dependence of the change in Gihhs energy, enthalpy and entropy upon transfer of ethane and butane from the gas phase to water. The data refer to transfer from the vapour phase at 0.101 MPa to a hypothetical solution of unit mole fraction and are taken from ref. 125.

Dehydrogenation (Section 5 1) Elimination in which H2 is lost from adjacent atoms The term is most commonly en countered in the mdustnal preparation of ethylene from ethane propene from propane 1 3 butadiene from butane and styrene from ethylbenzene... 

Figure 4-1. Vapor-solid equilibrium constant for (a) methane, (b) ethane, and n-butane. (From Gas Processors Suppliers Association, Engineering Data Book.)...

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. 

The observed product distribution indicates that Reaction 4 consumes virtually all methyl radicals. The formation of ethyl radicals is rapidly enhanced by electrostatic fields, clearly evident from the large increase in the yields of butane and ethane. These result predominantly from Reactions 5a and 5b. 

Figure 2.5 The response of an MISiC sensor, (a) At 600°C to gas mixtures containing different hydrocarbons (butane, propene, ethane) and concentrations. (From [56]. 1997 Elsevier B.V. Reprinted with permission.) (b) To hydrogen in different oxygen concentrations at 300°C and at T> 600°C plotted versus the ratio of reducing to oxidizing species, a, as defined in (2.6). Inset the pulse response at 620°C to 0.1, 0.2, and 0.3% Hj in 0.1% Oj/Ar. (From [57]. 1 988 The Electrochemical Society. Reprinted with permission.)...

Parent name a base from which other names are derived e.g., ethanol, from ethane butanoic acid, from butane. 

Water quality and the components present in the solution matrix can affect the reaction rates and product distribution, and can cause the catalyst to deactivate by slowing or eliminating the desired reaction. For example, Muftikian found ethane as the sole product from a 20 mg/L solution ofTCE, but observed butane and ethane from a saturated TCE solution. (Muftikian et... 

Table I illustrates typical products obtained on pyrolyz-ing the relatively light feedstocks from ethane through butane, but significant variations occur because of the design and operating conditions employed with each light paraffin. The compositions of products obtained from naphthas, gas oils, and even heavier feedstocks differ to an even greater extent the compositions of these heavier feeds vary over wide ranges. Tables II and III report typical...

Recently, attention has been shifted to the oxidative functionalisation of saturated molecules. Reactions such as from ethane —> vinylchloride, propylene — methacrylic acid, or butane -> maleic anhydride, became a target of many research efforts. A catalyst which appeared to be very versatile in such reactions is vanadyl pyrophosphate, (VO)2P20y. The mechanism of oxidative functionalisation is not yet known in all details, but there are many indications that it is in some crucial steps different from the mechanism operating with olefins (see also Chapter 5). 

Figure 2 demonstrates the impact of solvent quality and hydrogen bonding on the solubility of EMA31. Increasing the size of the alkane increases its polarizability and its critical temperature. Hence, the solvent quality increases going from ethane to butane and the cloud-point curves shift to lower temperatures and pressures. 

A block diagram for a gas processing plant is shown below. The purpose of this process is to recover ethane and propane (+ butane) from a natural-gas stream because these components have more value as chemicals than as fuel. This problem is based upon the 1987 AIChE Student Contest Problem. 

We performed extensive studies to determine the Cl-atom rate constant of benzene. n-Butane and ethane were among first molecules that were used as references to measure the relative rate constant of Cl-atom reaction of benzene. By the end of these experiments, the concentration of reference molecules reduced close to the detection limits whereas no decay of benzene outside the uncertainty limits was observed. Although the relative rate technique is particularly powerful in the measurement of reactions with comparable rate constants, for reactions with very different rate constants, this method is less accurate. Since it has become clear that the Cl-atom rate constant of benzene is slow, chloromethane, dichloromethane, and trichloromethane (chloroform) were used as references. These sets of experiments consisted of 20 individual experiments in which the concentration of hydrocarbons ranged from 10 to 15 mTorr and the concentration of CI2 varied from 10 to 100 mTorr. The relative rate constants for chloromethane and dichloromethane have been previously measured by Niki et al. [65]. Specifically, they were combined as a check on the experimental procedures. No difference in the values of the rate... 

If the assumption of constancy held exactly, it would be possible to deduce jE (CH) from methane and jF(G - G) from ethane, and to use these values to give the heats of formation of all paraffins. This is not in fact possible. The increment per GH2 group to the heat of formation is not constant for the lower n-paraffins, but becomes so only at -pentane 6. Moreover, if the assumption of constancy held exactly, all isomeric paraffins should have the same heat of formation. This is not so. For example, the heats of formation ( - A// ) at 298-16 K of n-butane and wo-butane are 29kcal and 31 45 respectively, and those of n-pentane and neo-pentane are 35-Oq and 39 67 kcal. This effect persists at 0 428, jf the... 

The presence of alkyl substituents can markedly increase the rate of the acid-catalyzed reaction [64] (cf. second-order rate constants for dehydration of the radicals from ethane-1,2-diol [61] and butane-2,3-diol [65] of 9 x 10 and 1.3 X 10 M s respectively). Alkyl substituents also increase the rate of loss of OH in their ionized counterparts (Scheme 4) [63]. 

The unsaturated dibasic acids bear the same relation to the saturated dibasic acids, just considered, as the unsaturated mono-basic acids, acrylic acid, crotonic acid, etc. (p. 172), do to the saturated monobasic acids, acetic acid, etc. They are also the oxidation products of the unsaturated hydrocarbons, alcohols, and aldehydes just as oxalic and succinic acids are of the corresponding saturated compounds. As the simplest dibasic acid containing an ethylene unsaturated group will contain two carboxyl groups and also two doubly linked carbon atoms there must be at least four carbons in the compound. This compound will therefore correspond to succinic acid of the saturated series. Now succinic acid may be derived from either butane by oxidation or from ethane by substitution. Similarly the corresponding unsaturated acid may be derived from butene by oxidation or from ethene by substitution. All of these general relationships may be represented as follows ... 

The selectivity to the product of partial oxidation is a function of the structure of the reactant. From n-butane and n-pentane the seleetivity to maleic anhydride and to maleic plus phthalic anhydrides, respectively, is high, while from ethane the prevailing products are either ethylene or earbon oxides (depending on the reaetion conditions) acetic acid is formed in rather low amounts. From propane very low amounts of acrylic acid are formed, and carbon oxides prevail. These differences can be attributed to the formation of very stable products... 

In general, the oxidized product from the pressure oxidation of hydrocarbons from ethane up to butane or higher in molecular weight may be expected to consist of a mixture of oxygenated organic compounds comprising alcohols, aldehydes, ketones, acids, esters, etc., together with water... 

Both of the above equations give good results for surface tension. A comparison of values from Equations (1-4) and (l 4a) with experimental data (37) provided essentially equivalent results for methane and butane. For ethane and propane, better agreement of correlation and experimental data was achieved with Equation (1-4). 

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