In this review, we summarize the latest technologies for the recovery and purification of crude glycerol and applications of crude glycerol, with focus on its chemical conversion.

This paper, for the first time, presents a novel, robust, and efficient high-quality reduced graphene oxide quantum dot (GQD)-based adsorbent for addressing the alarming environmental pollution issues nowadays. Such GQDs were fabricated in a facile manner via a combined green chemistry (GC) and temperature-controlled sonication irradiation (TSI) process. The mechanism underlying the fragmentation of the reduced graphene oxide (RGO) sheets prepared by GC with vitamin C (VC) as the only reactant to regulate the microstructure of graphene oxide (GO) was clarified through various characterization techniques such as X-ray diffraction, Raman, Brunauer−Emmett−Teller specific surface area measurements, transmission electron microscopy, scanning electron microscopy, elemental mapping, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, photoluminescence spectroscopy, selected area electron diffraction, and energy dispersive spectroscopy. The GQDs were assumed to be generated via cutting the nanometer-size sp 2 domains or clusters out of the RGO sheets along the defect sites decorated with oxygen groups and sp 3 carbons. The adsorption of the methylene blue (MB) dye onto the prepared GQDs was fast and obeyed the pseudo-second-order kinetic model, while the Freundlich adsorption isotherm was more suitable to fit the experimental data, as a result of the preferential enrichment of the organic dye molecules onto the edges rather than the homogeneous adsorption over the entire surface of GQDs. This could also be evidenced by the finding that the smaller was the lateral size of the RGO sheets, the stronger were the adsorption interactions with the MB dye. The dangling bonds with nonbonding electrons on the RGO edges were thus believed to play a significant role in the heterogeneous adsorption of the dye molecules through donor−acceptor charge transfer interactions. Impressively, the striking edge effect rendered the GQDs highly adsorptive toward the organic dye, with the maximum adsorption capacity calculated to be 827.5 mg g −1 for MB, outstripping most of the reported adsorbents. In addition, this GQDs-based adsorbent was found to be durable for many runs of repeated usage, and its universality was also demonstrated through efficiently binding with rhodamine B.

Industrial emissions of volatile organic compounds are urgently addressed for their toxicity and carcinogenicity to humans. Developing efficient and eco-friendly reforming technology of volatile organic compounds is important but still a great challenge. A promising strategy is to generate hydrogen-rich gas for solid oxide fuel cells by autothermal reforming of VOCs. In this study, we found a more desirable commercial catalyst (NiO/K2O-γ-Al2O3) for the autothermal reforming of VOCs. The performance of autothermal reforming of toluene as a model compound over a NiO/K2O-γ-Al2O3 catalyst fitted well with the simulation results at the optimum operating conditions calculated based on a simulation using Aspen PlusV11.0 software. Furthermore, the axial temperature distribution of the catalyst bed was monitored during the reaction, which demonstrated that the reaction system was self-sustaining. Eventually, actual volatile organic compounds from the chemical factory (C9, C10, toluene, paraxylene, diesel, benzene, kerosene, raffinate oil) were completely reformed over NiO/K2O-γ-Al2O3. Reducing emissions of VOCs and generating hydrogen-rich gas as a fuel from the autothermal reforming of VOCs is a promising strategy.