Production of hydrogen-rich gas from waste rigid polyurethane foam via catalytic steam gasification.

Catalytic steam gasification of waste rigid polyurethane foam, in the fixed-bed reactor, was performed to produce hydrogen-rich gas. The influence of nine kinds of additives on the yield of products (gaseous, solid and liquid product) and the volume fraction of hydrogen was investigated. Among the additives, calcium carbonate, as the catalyst, could effectively enhance the gas yield and the volume fraction of hydrogen. A three-factor three-level completely randomised factorial (3 × 3 × 3) design, with calcium carbonate as the catalyst, was applied to investigate the influence of experimental conditions (temperature, steam flowrate and catalyst dosage) on the volume fraction of gaseous product components. The data were processed with SPSS statistical software. The result showed that the main effects of one variable, the interactive effects between two factors and the interactive effects among three factors all have statistical high significance. The best catalysed process is realised when calcium carbonate is the catalyst, gasification temperature is 1100°C, steam flowrate is 0.7 kg h-1, catalyst dosage is 10 wt% of waste rigid polyurethane foam. Under this condition, the volume fraction of hydrogen reaches up to 79.85%.

The photocatalytic degradation of chloramphenicol with electrospun Bi2O2CO3-poly(ethylene oxide) nanofibers: the synthesis of crosslinked polymer, degradation kinetics, mechanism and cytotoxicity.

Insoluble poly(ethylene oxide) (PEO) nanofibers were synthesized by adding pentaerythrotol triacrylate (PETA) into precursor solutions prior to electrospinning, and then the obtained fibers were exposed to an electron beam (EB) irradiation. Bi2O2CO3 was incorporated into these fibers to extend their photocatalytic properties. Studies confirmed that EB irradiation induced characteristic changes in PEO and led to the formation of a crosslinked structure, from which we optimized the irradiation dose of fibers as 210 kGy. The optimum PEO/Bi2O2CO3 membranes achieved 99.5% CPL degradation within 60 min, and we also proposed the possible degradation pathways of CPL in this study. Besides, all the water samples and extracts of nanomaterials showed no cytotoxicity on L-929 cells. The subtle variations in the cell viability of treated and untreated water samples could be due to the toxic intermediates arising from the photocatalytic process. Therefore, this photocatalyst-polymer membrane can be considered as a biocompatible composite system that can change the solubility of a polymer and also act as a highly efficient photocatalyst for organic wastewater treatments.