Hydrogenation of Anthracene in Supercritical Carbon Dioxide Solvent Using Ni Supported on Hβ-Zeolite Catalyst

Abstract

Catalytic hydrogenation of anthracene was studied over Ni supported on Hβ-zeolite catalyst under supercritical carbon dioxide (sc-CO2) solvent. Hydrogenation of anthracene in sc-CO2 yielded 100% conversion at 100 °C, which is attributed to the reduced mass transfer limitations, and increased solubility of H2 and substrate in the reaction medium. The total pressure of 7 MPa was found to be optimum for high selectivity of octahydroanthracene (OHA). The conversion and selectivity for OHA increased with an increase in H2 partial pressure, which is attributed to higher concentration of hydrogen atoms at higher H2 pressures. The selectivity reduced the pressure below 7 MPa because of enhanced desorption of the tetrahydro-molecules and intermediates from Ni active sites, due to higher solubility of the surface species in sc-CO2. The selectivity of OHA increased with the increase in catalyst weight and reaction time. The rate of hydrogenation of anthracene was compared with that found for napthalene and phenanthrene. The use of acetonitrile as co-solvent or expanded liquid with CO2 decreased the catalytic activity

In‐Situ Upgrading of Coal Pyrolysis Tar with Steam Catalytic Cracking over Ni/Al2O3 Catalysts

“…It has been reported that Ni is commonly used most in the hydrogenation process, which can form dehydrogenation and hydrogenation sites, being favorable for gas generation …”

“…As can be seen from Figure a, the decrease of tar yield and the increase of light tar yield indicate that Ni/Al 2 O 3 can catalyze tar cracking, which is consistent with the literature . Ni is also the active site for dehydrogenation and hydrogenation, which is favorable for the generation of H 2 , as shown in Figure c. In addition, the increase of water conversion confirms the role of Ni/Al 2 O 3 in catalysis of SCC.…”

The Impact of Ce-Zr Addition on Nickel Dispersion and Catalytic Behavior for CO2 Methanation of Ni/AC Catalyst at Low Temperature

“…Regarding the reduction peaks of nickel species in 7 Ni/AC catalyst, it can be seen that three obvious reduction bands are observed: the first band (I) at the lowest-temperature with a maximum around 228-231 ∘ C can be assigned to the well dispersed nickel species in the samples (may be assigned to the relatively free nickel species weakly interacting with support), which are easily reduced [29]. The low temperature band, the second band (II), shows a maximum at about 275-290 ∘ C, which may be due to the reduction of dispersed nickel species [55] and the third band (III) with a maximum around 343-357 ∘ C may be related to the reduction of bulk nickel species in intimate contact with the support [56]. The peak positions and their contribution are summarized in Table 3.…”

Synergistic Process for FCC Light Cycle Oil Efficient Conversion To Produce High-Octane Number Gasoline

“…At the same time, thermodynamic and kinetic analysis of mild and deep hydrogenation also confirm the above conclusion. 25 Therefore, lower reaction temperature, lower reaction pressure and higher space velocity should be adopted on the premise of achieving the basic requirements.…”