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Currently, solid waste residuals (originated from biomass sources) are not of proper utilization since they are usually disposed through landfill or they are being left to degrade naturally. These two pathways for disposing such waste are of negative influences on the surrounding environment because of releasing hazardous emissions that are accrued at atmosphere layers, leading to several problems such as air pollution and acid rains as well as climate change. Thus, the implementation of temperature-dependent process, under controlled conditions, to convert these solid residuals into valuable products is strongly stimulated globally. In an agreement with this trend, the current research study presents production of activated carbon (AC) species from cane bagasse (biomass-based waste) using thermochemical treatment. Functionalizing of these carbon species was consequently carried out to obtain efficient adsorbents for the production of highly pure grade of commercial phosphoric acid via disposal of its organic matter contaminants. Fictionalization stage had included loading molecules of phosphoric acid only or phosphoric acid/nickel onto the particles of the as-prepared activated carbon. These two structures could exhibit increased adsorption capability toward species of organic matters compared to that detected by blank particle of activated carbon. Specifically, 73.4, 79.3, and 99.0 mg g−1 were, respectively, observed as adsorption capacities for blank AC, acid-modified AC, and acid/ metal AC structures. The adsorption of organic matters by these three carbon-based structures showed similar isotherms as well as kinetics behavior. Particularly, pseudo-second-order and Langmuir models are assigned as the best fit for the experimentally acquired data during current investigation. Additionally, the studied thermodynamic parameters of organic matters capture indicated that the process is an endothermic, physical, and spontaneous process. [ABSTRACT FROM AUTHOR]

Hydrogen has recently become a prized resource to generate clean power owing to its massive energy content and harmless emissions produced during its combustion. However, other gases are always attached to hydrogen during its production via various routes. Therefore, the obtainment of hydrogen with high purity for use in energy production is generally questionable. In agreement with that goal, this study is directed toward the synthesis of activated-carbon-supported nickel nanoparticles as a novel composite membrane for hydrogen separation from gas mixtures. First, a type of solid residual (sawdust) was converted via thermochemical treatment into particles of activated carbon, which have enhanced surface properties. These carbon particles were then metalized by nickel nanoparticles using an electroless plating (ELP) technique. The obtained composite was subsequently turned into a disk-like membrane using hydraulic pressing, and was then thermally treated at high temperature to generate a dense-layered Ni membrane. Full characterization on a comparative basis between the blank and metalized carbon particles was carried out using X-ray diffraction (XRD), Fourier Transform infrared (FT-IR) spectroscopy, BET surface area analysis, transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA). The efficiency of the Ni-based membrane toward H2 separation was next tested through the use of gas mixtures composed of different hydrogen-to-nitrogen concentrations. A maximum hydrogen flux and hydrogen-to-nitrogen selectivity of 15.16 sccm cm−2 min−1 and 465, respectively, were attained at ambient temperature. Additionally, a hydrogen permeability percentage of nearly 80% (from the original H2 stream) could be achieved by the designed Ni-membrane, which could offer synchronized hydrogen storage during the separation process. [ABSTRACT FROM AUTHOR]

The current study described the synthesis of H-ZSM-5 zeolites with hierarchical micro-meso- porosity (HM-ZSM-5- x) via the soft-templating route, employing organosilane surfactant, 3-[(trimethoxysilyl) propyl]octyldimethylammonium chloride, as the mesoporous template. The catalytic performance was examined in the isomerization of o-xylene in a fixed-bed reactor at atmospheric pressure. Many techniques were conducted to characterize the catalysts. The X-ray diffraction (XRD) and Fourier Transform Infra Red (FTIR) results affirmed that all mesoporous zeolites possess the characteristic MFI structure, as well as good crystallinity. The N2 physisorption measurements signified that all HM-ZSM-5-x samples have higher surface areas and pore volumes than the micro-ZSM-5 sample, with the mesopores accounting for the vast majority of the total surface areas and pore volumes of HMZSM-5-x samples. Moreover, the mesoporosity of the obtained HM-ZSM-5-x zeolites can be simply tuned via the variation of the amount of TPOAC used. Compared with classical micro-ZSM-5, the HM-ZSM-5-0.15 sample possessed a higher o-xylene conversion and p-xylene yield that was attributed to its remarkable textural characteristics in terms of higher surface area and prevailing mesoporous character that led to a reduced diffusion limitation. Importantly, the catalyst manifested superb operational stability within 50 h, indicating high resistance against deactivation through coke deposition. [ABSTRACT FROM AUTHOR]