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This article investigated extraction process of molybdenum (VI) from acid leaching solution to explore the basic data for the recovery of Mo resources from spent hydroprocessing catalyst. The extractant 2‐ethylhexyl phosphonic acid mono‐2‐ethylhexyl ester (P507) was adopted as the extractant, and the effects of specific operating parameters on Mo extraction and stripping were systematically investigated. The Mo extraction was greater than 99.5%, and the co‐extraction of Al and Co were less than 0.2% under optimal conditions. The corresponding stripping processes were also performed focusing on reducing phase‐separation time and preventing third‐phase generation. Almost 100% (>99%) Mo was easily stripped using 0.9 mol/L NH3·H2O with the addition of NH4NO3 ranging from 0.3 to 1.2 mol/L. Saturation extraction capacity method was applied to explore extraction mechanism. Results indicated that the molar ratio of Mo to P507 in the saturated organic phase was approximately 1:1, so the extraction reaction can be expressed as follows:2H3MoO4++H2A2¯→2H3MoO4A¯+2H+H6Mo2O82++H2A2¯→H6Mo2O8A2¯+2H+ © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019 [ABSTRACT FROM AUTHOR]

Abstract The hydrogenation of acetylenic contaminates into valuable chemicals is a clean and promising process for minimizing the waste and improving economic benefits. In this work, the enhancement of Ag on Ni/Al 2 O 3 catalyst for acetylenic stream hydrogenation was studied by multiple characterization techniques and DFT calculations. The addition of Ag shows negligible effect on the particle size of Ni nanoparticles, but modifies the electronic and geometric structures of Ni active sites by electron transfer and site isolation, respectively, which weaken the adsorption strength of Ni sites for reactants and intermediates and thus suppress their polymerization. Due to the enhancement of Ag, Ni-Ag/Al 2 O 3 catalyst exhibited excellent performance for the hydrogenation of acetylenic contaminates for a 700-h evaluation: ∼99.8% of total conversion and ∼98% of butane selectivity. Moreover, besides the high-quality products of butane, the results of simulation by Aspen Plus simulator indicates that 98% of benzene in acetylenic contaminates can be recovered as a chemical product with 99% of purity. This Ni-Ag/Al 2 O 3 catalyzed hydrogenation process for acetylenic contaminates exhibits a potential of substantial economic and green benefits for the industrial production. Highlights • Ni-Ag/Al 2 O 3 catalytic conversion of acetylenic contaminants into valuable product was explored. • The performance of Ni-Ag/Al 2 O 3 catalyst was greatly enhanced compared to Ni/Al 2 O 3. • The enhancement of Ag was elucidated by multiple characterization techniques and DFT calculations. • In the proposed process, the yield of target products was simulated and investigated by Aspen Plus simulator. [ABSTRACT FROM AUTHOR]

A tailor-made encapsulated catalyst with SAPO-34 zeolite shell has been synthesized over Fe 3 C nanoparticles to form a core-shell structure via surface modification of Si-OH groups. The core-shell structure catalyst Fe/C@Si-SAPO are investigated via Fischer-Tropsch synthesis to evaluate their catalytic performance on the direct synthesis of light olefins from syngas. In comparison with the simple mixing structure of the traditional mixture catalyst, the special core-shell of this SAPO-34 zeolite capsule catalyst has an obvious confinement effect on the controlled synthesis of light olefins from syngas. Interestingly, it gives a completely different product distribution from the traditional mixture catalyst and the formation of C 6+ hydrocarbons is completely suppressed. In addition, the Fe/C@Si-SAPO catalyst promoted by K were found to decrease the methane selectivity, increase the olefin/paraffin ratio and shift the product selectivity to light olefins during FTS. [ABSTRACT FROM AUTHOR]