Adsorptive desulfurization of propylene derived from bio-ethanol

We studied adsorption characteristics of a series of LTA zeolite as an adsorbent for desulfurization of propylene, that was produced from bioethanol by ethanol-to-olefin (ETO) conversion. A breakthrough curve (BTC) for adsorption of methanethiol, as one of the sulfur impurities of propylene produced from bioethanol, in the presence of propylene was measured using a fixed-bed column packed with the LTA zeolite. The BTC revealed that the effect of the competitive adsorption of propylene on the LTA zeolite strongly depended on a cation species exchanged in the micropores of the zeolite. Among the cation species examined in this study, bivalent cation of zinc (Zn²⁺) was proved to be the most effective one to increase the amount of methanethiol adsorbed on the LTA zeolite under the presence of propylene. The specific interaction of methanethiol with the LTA zeolite exchanged with Zn²⁺ was confirmed by the measurement of a temperature-programmed desorption (TPD) spectrum of methanethiol.     

Preparation of macroporous carbon foam using emulsion templating method

A macroporous carbon foam (MCF) possessing three-dimensionally interconnected porous structure, that was composed of macropores, mesopores and micropores, could be synthesized by the oil-in-water (o/w) emulsion templating method using ultrasound. For the preparation of the o/w emulsion as a template of the macropores formed in the MCF, a resorcinol-formaldehyde (RF) solution and cyclohexane were used as an aqueous phase and an oil phase, respectively. We examined the effects of the viscosity of the RF solution, the mass ratio of cyclohexane with the RF solution as well as the concentration of a hydrophilic surfactant (Tween80) contained in the RF solution on the size distribution of the macropores. Consequently, the suitable viscosity of the RF solution to obtain a MCF with a narrow size distribution of the macropores was determined. It was revealed that the size of the macropores increased with the increase in the mass ratio of cyclohexane with the RF solution or with the decrease in the concentration of Tween80. It was possible to increase the porosity of the prepared MCF larger than 90% using a concentrated o/w emulsion as the template of the macropores.     

Preparation and characterization of nickel-modified carbon cryogel beads with uniform particle size

Nickel-modified carbon cryogel beads (Ni/CCBs) with uniform particle size were successfully prepared using the syringe injection method, employing sol–gel polycondensation of a resorcinol–formaldehyde (RF) solution containing Ni acetate as a catalyst. This process was followed by solvent exchange, freeze-drying and carbonization in a nitrogen atmosphere. The effect of viscosity, which increased as the sol–gel polycondensation progressed, of the RF solution on both the particle size distributions of the Ni/CCB and the porous properties was investigated. The influence of Ni content in the initial reactants on the porous properties of the Ni/CCBs was also studied. Monodisperse Ni/CCBs could be obtained by injection during the initial reaction period, before the steep increase in the viscosity of the RF solution. The porous properties of the Ni/CCBs were independent of the viscosity of the RF solution. The BET surface area, micropore volume and mesopore volume of Ni/CCBs decreased with increased Ni content, whereas the macropore volume increased with increased Ni content. The size of the Ni nanoparticles dispersed in the carbon matrix of Ni/CCBs was confirmed to range from 30 to 60 nm.