In recent years, mixed matrix membranes (MMMs) have received worldwide attention for their potential to offer superior gas permeation and separation performance involving CO2 and CH4. However, fabricating defect-free MMMs still remains as a challenge where the incorporation of fillers into MMMs has usually led to some issues including formation of undesirable interfacial voids, which may jeopardize the gas separation performance of the MMMs. This current work investigated the incorporation of zeolite RHO and silane-modified zeolite RHO (NH2–RHO) into polysulfone (PSf) based MMMs with the primary aim of enhancing the membrane’s gas permeation and separation performance. The synthesized zeolite RHO, NH2–RHO, and fabricated membranes were characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared-attenuated total reflection (FTIR-ATR), thermogravimetric analysis (TGA) and field emission scanning election microscopy (FESEM). The effects of zeolite loading in the MMMs on the CO2/CH4 separation performance were investigated. By incorporating 1 wt% of zeolite RHO into the MMMs, the CO2 permeability and ideal CO2/CH4 selectivity slightly increased by 4.2% and 2.7%, respectively, compared to that of a pristine PSf membrane. On the other hand, a significant enhancement of 45% in ideal CO2/CH4 selectivity was attained by MMMs incorporated with 2 wt% of zeolite NH2-RHO compared to a pristine PSf membrane. Besides, all MMMs incorporated with zeolite NH2-RHO displayed higher ideal CO2/CH4 selectivity than that of the MMMs incorporated with zeolite RHO. By incorporating 1–3 wt% zeolite NH2-RHO into PSf matrix, MMMs without interfacial voids were successfully fabricated. Consequently, significant enhancement in ideal CO2/CH4 selectivity was enabled by the incorporation of zeolite NH2–RHO into MMMs.

Abstract. Date palm fronds (DPF) have similar physical appearances to those of oil palm fronds and coconut palm fronds, which have been reported as having good potential as a source of energy through thermochemical conversion of biomass. However, nearly no report has been found pertaining to thermochemical properties of DPF. Hence, it has remained unclear whether DPF can become suitable feedstock for power generation. This study investigated the characteristics of DPF as a potential solid fuel for heat and power generation through various thermal conversion processes. DPF samples from selected sites in Sudan and Saudi Arabia were tested. The ultimate and proximate analyses and the calorific value of DPF were measured, and the results were compared with low to medium-rank coals and other common biomass materials. The calorific value range for DPF samples was found to be between 16.2 to 16.9 MJ/kg. The ultimate analysis of DPF samples revealed that more than 75% of their mass was composed of volatile materials, while the ash content in all samples was found to be less than 15%. The range of elementary carbon, hydrogen, nitrogen, sulfur and oxygen in DPF samples was found to be typical to that in biomass. The thermal decomposition trends the samples indicated the high reactivity of DPF with rising temperatures due to high holocellulose content. No distinctive differences in test results were observed between samples from Saudi Arabia and Northern Sudan. Overall, it was found that all DPF samples used in this study fulfilled the typical requirements for development and utilization as a solid fuel.

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Over the years, functionalization of zeolite is gaining popularity among researchers to further modify the properties of the zeolite for wide applications. The procedure of functionalization is crucial to ensure that the framework and structure of the zeolite would not be destroyed by the functionalization process. In this work, zeolite AlPO-18 was synthesized via hydrothermal synthesis method and functionalized by (3-Aminopropyl) triethoxysilane (APTES). The effect of the APTES functionalization on zeolite AlPO-18 was investigated in this work. Both unfunctionalized and silane-functionalized zeolite AlPO-18 were characterized using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and Thermogravimetric analysis (TGA) for their properties. The morphology and the composition of the elements present in zeolite AlPO-18 and zeolite NH2-AlPO-18 were examined using Field Emission Scanning Electron Microscopy (FESEM) and Energy-Dispersive spectroscopy (EDX) respectively. The XRD pattern of NH2-AlPO-18 was similar to that of zeolite AlPO-18, however, the intensity of the peaks was lower compared to zeolite AlPO-18. Based on the FTIR spectra, the presence of N-H stretching and bending vibration band of aminosilane were observed in the NH2-AlPO-18 sample. According to FESEM images, the morphology of NH2-AlPO-18 was comparable to that of zeolite AlPO-18 even after functionalization, proving that functionalization of aminosilane on zeolite does not affect on the zeolite structure. Besides that, EDX proves the presence of 3.02 % of element N in the NH2-AlPO-18 sample which is absent in the zeolite AlPO-18 sample. All of the characterizations evinced the presence of aminosilane, APTES in the NH2-AlPO-18 sample.

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