Decalin, cracking

Ryoo and co-workers synthesized MFI zeoHtes with varied morphology by means of a surfactant as structure-directing agent [76]. The zeolitic catalysts so fabricated were found to exhibit superior catalytic activities during decalin cracking reactions. To correlate the observed reactivity with acid properties of the catalysts, the P-R3PO NMR approaches with TMPO and TBPO probe molecules were exploited. The P NMR spectra of TMPO and TBPO adsorbed on various MFI zeohtes are compared to a... 

Furthermore, while no significant difference in the product distribution, with the exception of the trans-decalin/cis-decalin ratio, is observed for the tested proton-form zeolites, dissimilarity between Pt/H-Y on one hand and both Pt/H-Beta zeolites on the other hand is found (Figure 6). More ROP and CP, accompanied by less Iso, are formed on Pt/H-Y than on Pt/H-Beta zeolites. This implies that the consecutive ring opening and cracking are faster over Y-zeolite than over Beta-zeolites resulting in lower concentration of isomers and higher concentrations of ROP and CP. 

Fig. 15 A proposed reaction network of direct ring opening of decalin reaction over acidic zeolites. PC Protolytic cracking HeT Hydride transfer HT Hydrogen transfer I Isomerization P /i-scission DS Desorption TA Transalkylation. Adapted from ref. 47.

Fig. 16 Concentration of decalin and product groups as a function of conversion over H-Beta (filled), HY (open), and H-Mordenite (half-filled). CP = cracking products ROP = ring opening products HP = heavy products. Adapted from refs. 44 and 45. 

Four model compounds, n-undecane, tetralin, cis/trans decalin and mesitylene, and a natural gas condensate from the North Sea were also cracked. Analyses and the reference code key of the coal-based feedstocks and the gas condensate are given in Table 1. Paraffin, naphthene, and aromatic-type analyses were calculated from gas chromatographic analyses of the partially hydrogenated anthracene oil and gas condensate whereas, mass spectrometric analysis was performed on the two coal extract hydrogenates and their further hydrogenated products. 

Model Compounds - Four model compounds (mesitylene for aromatics, tetraline for hydroaromatics, decaline for naphthenes, and n-undecane for paraffins) were cracked singly and as mixtures at 1133°K for 1 s. The yields of BTX, ethylene, butadiene, and methane are shown as a bar chart in Figure 4. Decalin gave the highest BTX yield, 25%, compared with less than 7% from n-undecane. Mesitylene gave only 8% BTX. 

Figure 4. Variation of yields with hydrocarbon type P = paraffin (n-undecane), N = naphthalene (cis/trans decalin), HA = hydroaromatic (tetralin), A = aromatic (mesitylene) cracking temperature, 1133 K vapor residence time, 1 s...

Y. Matsnmoto, Cracking styrene derivative polymers in decalin solvent with metal-supported carbon catalysts, J. Mat. Cycles Waste Man., 3, 82-87 (2001). 

The hydropyrolysis of a representative polycyclic naphthene, i.e., decalin (2), was investigated as a function of reaction temperature (525°-625°C) and hydrogen pressure 500-2000 psig). In addition, a comparison between hydropyrolysis and thermal cracking of 2 was made by doing a parallel study with this compound under nitrogen pressure, using otherwise identical experimental conditions. The apparatus and experimental methods were the same as in the study of n-hexadecane (see Experimental section). 

Table V. Comparison of Product Composition from Hydropyrolysis (HP) and Thermal Cracking (TC) of Decalin (2)° d...

Cracking of decalin, centane, cumene, light gas oil, heavy oil Al-R Good olefin production. Activity and stability > USY, resulting in high selectivity to isobuytlene and isoamylene. 48... 

We attempted to compare our results to earlier reports for catalytically active Si-VPI-5 samples, however, relevant results for a direct comparizon were not found. Martens et al. [6] and Kraushaar-Czametzki etal. [13] reported their results for Pt/Si-VPI-5 bifunctional catalysts in the isomerisation of n-decane [6], and in the hydroconversion of n-heptane, respectively. Davis et al. also used metals supported on VPI-5 to test catalytic reactions [12]. Our main interest were the cracking capability and the selectivity to useful fuel fractions, using the Si-VPI-5 catalysts in reactions of trans-decalin (model compound) or atmospheric residue. 

In the case of bicyclic naphthenes most of the work in catalytic cracking was done using decalin (Bloch and Thomas, 15 and Greensfelder... 

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