Hydrocarbon processing paraffins

Natural gas and crude oils are the main sources for hydrocarbon intermediates or secondary raw materials for the production of petrochemicals. From natural gas, ethane and LPG are recovered for use as intermediates in the production of olefins and diolefms. Important chemicals such as methanol and ammonia are also based on methane via synthesis gas. On the other hand, refinery gases from different crude oil processing schemes are important sources for olefins and LPG. Crude oil distillates and residues are precursors for olefins and aromatics via cracking and reforming processes. This chapter reviews the properties of the different hydrocarbon intermediates—paraffins, olefins, diolefms, and aromatics. Petroleum fractions and residues as mixtures of different hydrocarbon classes and hydrocarbon derivatives are discussed separately at the end of the chapter. 

For the range of industrially relevant conditions, the developed model could accurately predict both the observed CO conversion and the products distribution up to n = 49, in terms of total hydrocarbons, n-paraffins, and a-olefins. In particular, using thirteen adaptive parameters, the model is able to describe the typical deviations of the product distribution from the ASF model, i.e., the methane high selectivity, the low selectivity to C2 species, and the change of the slope of the ASF plot with growing carbon number. Accordingly, the present model can be applied to identify optimized process conditions that are suitable to grant the desired conversion with the requested products distribution. 

Uses Solvent standardized hydrocarbon manufacturing paraffin products jet fuel research paper processing industry rubber industry organic synthesis. 

Like other hydrocarbons, the paraffin wax in candles undergoes combustion when burned. It releases thermal energy in the process. In the following investigation, you will measure this thermal energy. 

The effect of trace contaminants on the reaction has been investigated carefully. All uncondensed effiuent gases were recycled to the reactor, except for the amounts present in the streams taken off for analysis or flashed upon depressuring of the organic phase. Aqueous phase from the separator containing the water soluble by-products has been used as the water feed to the reactor. Hydrogen chloride containing chlorinated hydrocarbons and acetylene was used in all operations. In addition, certain possible impurities were tested for their effect on the kinetics and selectivity of the process. Paraffins, carbon monoxide, sulfide, carbon dioxide, alkali, and alkaline earth metals were found to be chemically inert. Olefins, diolefins and acetylenic compounds are chlorinated to the expected products. No deleterious effects of by-product recycle were observed even when some of the main by-products were added extraneously. 

Thus, by the occurrence of many variations of processes, such as these, thermal cracking produces a mixture of gaseous and liquid hydrocarbons of paraffinic (saturated) and olefinic (unsaturated) types, plus coke (Eq. 18.16). 

As a rule, this method can be applied to the oxidation of any paraffinic or olehnic hydrocarbon, pure or in a mixture, using air, sometimes enriched with oxygen. Industrial plants mainly process paraffins (propane, n-butane and light gasolinei However, considerable development work has been conducted on the conversion of olefins, and more predsely n-butenes, by direct oxidation or indirect oxidation (intermediate formation of acetates). These developments have culminated in plant construction in Western Europe only. 

H. Franz, Urea Dewaxing Process Can Yield Normal Paraffins, Hydrocarbon Processing 44(9) 183-184 (1965). 

Asher, W.J. Campbell. M.L. Epperly, W.R., and Robertson, J.L., Desorb n-paraffins from molecular sieves with ammonia, Hydrocarbon Process., 48(1), I34-I38 (1969). 

LaPlante, L.J., and Symoniak, M.F., Molecular sieves for protein-from-paraffins process. Hydrocarbon Process., 49(12), 77-82 (1970). 

Petroleum fractions contain many different hydrocarbon molecules and ever more stringent environmental constraints now determine con iosition and purity requirements of the products. Furthermore, when upgrading different hydrocarbon streams the formation of side-products leads to even more complex mixtures. For example when producing linear olefinic hydrocarbons by paraffin dehydrogenation aromatic side-products are formed [28]. Often, alkane/alkene/aromatic hydrocarbon mixtures have to be separated. For the liquid phase separation of normal alkenes from n-alkene/n-alkane mixtures, the OLEX process was developed [2]. Also, the separation of alkane/alkene mixtures by adsorption via Ji-complexation has been extensively studied [29-31]. However, no industrial adsorptive separation processes are available for the separation of either alkanes or alkenes of different chain length. Rather, a downstream distillation section is used as to separate for exan5)le the linear aZp/jfl-olefins (C4-C10) produced by the AlphaSelect Process (IFP) [32]. 

Most hydrocarbons are paraffins, but olefins and alcohols are also produced in lower concentrations than the paraffins. The product distribution of these polymers follows a Schulz-Flory distribution of molar masses usually formed in polymerization processes. Initially, the process was used to make gasoline from coal via "syn gas . Specialty chemicals have been looked for more recently, starting from alkenes made from syn gas derived from natural gas (methane) or coal. The formation of hydrocarbons from CO and H2 is thermodynamically favorable. For instance, for propene ... 

Fig. 22.38. Separation of high purity Cio-C2.j normal paraffins from kerosene. (Hydrocarbon Processing, SO,...

One version of the UOP IsoSiv process uses PSA to separate normal paraffins from branched and cycHc hydrocarbons in the to range. 

The fermentation of / -paraffins in the C q to range for protein production has provided a new oudet for these hydrocarbons (see Foods, nonconventional). Because it operates in Hquid phase, the UOP Molex process can readily accomplish the separation of / -paraffins from such a wide boiling feedstock. 

However, ia some cases, the answer is not clear. A variety of factors need to be taken iato consideration before a clear choice emerges. Eor example, UOP s Molex and IsoSiv processes are used to separate normal paraffins from non-normals and aromatics ia feedstocks containing C —C2Q hydrocarbons, and both processes use molecular sieve adsorbents. However, Molex operates ia simulated moving-bed mode ia Hquid phase, and IsoSiv operates ia gas phase, with temperature swiag desorption by a displacement fluid. The foUowiag comparison of UOP s Molex and IsoSiv processes iadicates some of the primary factors that are often used ia decision making ... 

Secondary alcohols (C q—for surfactant iatermediates are produced by hydrolysis of secondary alkyl borate or boroxiae esters formed when paraffin hydrocarbons are air-oxidized ia the presence of boric acid [10043-35-3] (19,20). Union Carbide Corporation operated a plant ia the United States from 1964 until 1977. A plant built by Nippon Shokubai (Japan Catalytic Chemical) ia 1972 ia Kawasaki, Japan was expanded to 30,000 t/yr capacity ia 1980 (20). The process has been operated iadustriaHy ia the USSR siace 1959 (21). Also, predominantiy primary alcohols are produced ia large volumes ia the USSR by reduction of fatty acids, or their methyl esters, from permanganate-catalyzed air oxidation of paraffin hydrocarbons (22). The paraffin oxidation is carried out ia the temperature range 150—180°C at a paraffin conversion generally below 20% to a mixture of trialkyl borate, (RO)2B, and trialkyl boroxiae, (ROBO). Unconverted paraffin is separated from the product mixture by flash distillation. After hydrolysis of residual borate esters, the boric acid is recovered for recycle and the alcohols are purified by washing and distillation (19,20). 

Fischer-Tropsch Process. The Hterature on the hydrogenation of carbon monoxide dates back to 1902 when the synthesis of methane from synthesis gas over a nickel catalyst was reported (17). In 1923, F. Fischer and H. Tropsch reported the formation of a mixture of organic compounds they called synthol by reaction of synthesis gas over alkalized iron turnings at 10—15 MPa (99—150 atm) and 400—450°C (18). This mixture contained mostly oxygenated compounds, but also contained a small amount of alkanes and alkenes. Further study of the reaction at 0.7 MPa (6.9 atm) revealed that low pressure favored olefinic and paraffinic hydrocarbons and minimized oxygenates, but at this pressure the reaction rate was very low. Because of their pioneering work on catalytic hydrocarbon synthesis, this class of reactions became known as the Fischer-Tropsch (FT) synthesis. 

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