Synthesis, isoparaffin

The isoparaffin synthesis studied at the Kaiser Wilhelm Institut fur Kohlenforschung (37, 67, 68, 69) is more closely related to the synthesis of the higher molecular weight alcohols using difficultly reducible oxides plus alkali as catalysts, than to the Fischer-Tropsch process. Thoria, zinc oxide. 

The capsule catalyst Co/SiO -Z with zeolite HZSM-5 as the shell and the Co/SiO -Z-Pd capsule catalysts were used for isoparaffin synthesis from syngas at H2/CO=2/l, 1.0 MPa and 533 K [107]. The isoparaffin and olefin selectivity increased for the HZSM-5-based capsule catalysts compared to the conventional Co/SiO catalyst. Supporting Pd by sputtering caused the selectivity to isoparaffins to increase, and the selectivity to olefins to decrease compared to the samples prepared by incipient wetness, because metallic Pd supported by sputtering on the zeolite shell could hydrogenate olefins efficiently. The CO conversion, CH and CO selectivity on the catalyst Co/SiO -Z-Pd prepared by sputtering increased with a temperature rise from 513 to 553 K. At elevated temperatures, the isoparaffin selectivity also increased, whereas the olefin selectivity diminished. 

Eleven isoparaffins having 16 to 34 carbon atoms per molecule were prepared in quantities of 600 to 1000 grams. Table I presents a brief description of the compounds. Details of the methods used in their synthesis and additional important physical properties will be presented elsewhere (10). The purity of all compounds is estimated to be 95 mole % or better. 

The CSSX process utilizes a novel solvent made up of four components calix[4]arene-bis-(4-fer/-octylbenzo-crown-6) known as BOBCalixC6 as extractant a lipophilic fluorinated alcohol, l-(2,2,3,3-tetrafluoropropoxy)-3-(4-. ec-butylphenoxy)-2-propanol known as Cs-7SB, as diluent modifier tri- -octylamine as a suppressor of impurity effects and the isoparaffinic diluent Isopar L, a mixture of branched hydrocarbons with an average chain-length of 12 carbons. Figure 3 shows the composition of the solvent as currently optimized for the SWPF application at the SRS [37,49], The chemistry of the solvent is well understood, with regards to both its fundamental properties and its performance under process conditions. All of the components are commercially available, and efficient synthetic and purification procedures have been worked out [17,18,37], Thus, these key components may be obtained from multiple chemical suppliers capable of specialty synthesis. 

It is used as a solvent and raw material for organic synthesis reactions and is a very important chemical in the petroleum industry. It is also widely used in the rubber and paper processing industries. Isooctane, along with other n- and isoparaffins, are used in the blending of fuels to achieve desired antiknock properties. A total of 17 isomers of octane are known to exist isooctane (2,2,4-trimethylpentane) is a principal ingredient of gasoline. 

Comparison of a Two-Stage Reactor and a Single Reactor for the Synthesis of Isoparaffin-Rich Gasoline from Propylene... 

Figure 2. Synthesis of isoparaffins in the gasoline range from propylene using a two-stage reactor at a much higher flow rate, (propylene GHSV= 5000 h other reaction conditions as in Figure lb).

Carbon dioxide-methane separation Solvent vapor recovery Hydrogen and carbon dioxide recovery from steam-methane reformer off-gas Hydrogen recovery from refinery off-gas Carbon monoxide-hydrogen separation Alcohol dehydration Production of ammonia synthesis gas Normal-isoparaffin separation Ozone enrichment... 

Fig. 4. Molar activity of synthesis products as a function of C number in the Co normal pressure synthesis after addition of [l- C]-n-hexadecene-l to the synthesis gas (relative molar activity of -C,4 in product 291,000) (O) n-paraffin ( ) monomethyl-paraffin ( ) n- and isoparaffins. From (20).

The fact that hydrocarbons constitute the chief product of isosynthesis results from the intense dehydrating action of thorium oxide and related catalysts. In the region of operation for this synthesis, low temperatures produce high yields of alcohols. A rise in temperature at first increases the iso-olefin yield then, as the hydrogenating power of the catalyst increases, isoparaffins are formed. A further rise in temperature produces naphthenes and finally, because of their high thermal stability, aromatics. 

Hydrogen and Cariwn Dtradde Productiaa fiom Steam-Methane Refinner OCf Gas Production of Ammonia Synthesis Gas Hydrogen Recovery fiom Refinery Off Gases Methane-Caibon Dioxide Separation fiom Landfill Gas Caihon Monoxide-Hydrogen Separation Normal - Isoparaffin Separation Alcohol Dehydration... 

He J, Yoneyama Y, Xu B, Nishiyama N, Tsubaki N. Designing a capsule catalyst and its application for direct synthesis of middle isoparaffins. Langmuir 2005 21 1699-1702. 

Cheng K, Kang J, Huang S, You Z, Zhang Q, DingJ Mesoporous beta zeohte-supported ruthenium nanoparticles for selective conversion of synthesis gas to C5-C11 isoparaffins, CS Catal 2(3) 441-449, 2012. 

Ru,Ni-promoted Co/HZSM-5 catalysts were efficient in the FT synthesis of gasoline-range hydrocarbons [101]. The activity increased significantly upon the addition of a Ru or Ni promoter. The CO conversion increased in the order Co/HZSM-5 < Ru-Co/HZSM-5 < Ni-Co/ HZSM-5. The Ru-Co/HZSM-5 catalyst is still active after 150h on stream at 540 K. The Ni-Co/HZSM-5 catalyst also showed good catalytic performance even at a lower temperature of 524 K. The temperature rise leads to the increase of the content of isoparaffins. 

Light isoparaffins can be produced from syngas on a hybrid (capsular) catalyst representing a mixture of the FT catalyst and zeolite [105]. The zeolite capsular catalyst with a core-shell structure was prepared using 10% Co/SiO as core catalysts and HZSM-5 zeolite. The performance of the capsule-type catalysts (Fig. 10) in the one-step synthesis of light isoparaffins was better (a higher selectivity) than that of the conventional hybrid catalyst. 

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