Minimum Cross Diameter for C₆–C₁₀ Aromatic Compounds

Abstract

The minimum cross diameter of organic species is highly important in catalyst and adsorbent design. In the aromatics industry, the size of the desired compound is the cornerstone of the commonly known shape-selective processes. In spite of the paramount importance of the said sizes, information in the literature is scarce and inconsistent. A thorough methodology was developed using the commercial software ChemBio3D Ultra. The minimum cross diameter of 21 aromatic compounds was calculated including benzene, toluene, ethylbenzene, xylene isomers, ethyltoluene isomers, diethylbenzene isomers, ethylxylene isomers, and trimethylbenzene isomers.

Gas-Phase Carbonylation of Dimethyl Ether on the Stable Seed-Derived Ferrierite

“…Therefore, not only the Si/Al ratios but also intrinsic micropore structures and their acidities for FER, MOR, and SSZ-13 seem to be important characteristics by largely altering catalytic performances. For example, the smaller 8-MR channels are responsible for the selective production of MA by DME carbonylation, and larger 10-MR channels and cavities are responsible for the selective coke depositions, which can prevent an easy diffusion of reactants to the active acidic site in the 8-MR channels due to their significant blockages by the formed bulk coke precursors. ,, Those natures can be analyzed by confirming the types of coke precursors with GC-MS and TGA analyses . The results of the coke precursor type and its amount on the used seed-derived FERs after DME carbonylation for 40 h on stream were analyzed by GC-mass and TGA, and the results are displayed in Figure A,B and Figure S8 in the Supporting Information.…”

Catalytic conversion of aromatics in fixed‐bed over several zeolites in the liquid phase

“…The feedstock was transferred into the oven (18), which was responsible for keeping the reaction at controlled temperature conditions, and the feed preheating to the desired temperature was done in the serpentine coil (16). At the outlet of the column (17), the effluent goes through a filter (19) to remove any particle or dust of the catalyst. To avoid evaporation before sampling, the stream was cooled down in a serpentine (21) placed inside a water bath (20) at room temperature (around 295 K).…”

“…The minimum cross‐diameter of PX, OX, and MX are 6.63, 7.25, and 7.27 Å, respectively. [ 19 ] The reduced pore size will create diffusion limitations for molecules that are too bulky, and by staying longer in contact with the active acid sites, it increases the probability to be converted into other products. [ 17 ] In this case, OX and MX are expected to stay longer in the catalyst pores and therefore being transformed into PX.…”

“…Experimental setup of the fixed-bed system: (1) heptane bottle, (2) feed mixture, (3) air supply, (4) nitrogen supply, (5, 7) highperformance liquid chromatography (HPLC) pumps, (6) three-way valve,(11,12,13,14,15) on-off valves, (8, 9, 10) needle valves,(16,21) serpentine coil, (17) fixed-bed SS316 column, (18) oven,(19) in-line filter, (20) thermostatic bath, (22) back-pressure regulator, (23) waste bottle, and (24) auto sampler…”

Modulating the stacking modes of nanosized metal–organic frameworks by morphology engineering for isomer separation

“…The minimum cross diameter of 4-ethyltoluene is $6.63Å, which is signicantly smaller than those of the other two isomers ($7.96Å for 2-ethyltoluene and $7.26Å for 3-ethyltoluene), indicating that 4-ethyltoluene can more readily enter the pores of NU-901 ($6Å for NU-901-NP). 35 Thus, the paraisomer has stronger interactions with the MOF stationary phases, while the ortho-and meta-isomers exhibit mild interactions with short retention. This para-selectivity of NU-901-NP provides the opportunity to separate para-isomers from the mixtures to obtain industrially important raw chemicals.…”