An experimental and kinetic study of thermal decomposition of phenanthrene

Gasification of municipal solid waste (MSW) as a cleaner final disposal route: A mini-review

The production of hydrogen-rich syngas from municipal solid waste (MSW) by pyrolysis/gasification is one of the most promising waste-to-energy pathways for realizing a circular bioeconomy. This mini-review provides an overview of current research and development efforts in the field, focusing on the development of syngas upgrades and novel gasification processes, with the ultimate goal of making MSW gasification a sustainable and affordable route for the final disposal of MSW. A graphical assessment protocol is proposed to support comprehension of the main reactions that are involved in the MSW gasification. MSW gasification studies are reviewed with the prospects considered to provide a reference for future work.

In situ fabrication of I-doped Bi2O2CO3/g-C3N4 heterojunctions for enhanced photodegradation activity under visible light

Iodine-doped Bi₂O₂CO₃/g-C₃N₄ heterojunctions consisting of graphitic carbon nitride (g-C₃N₄) and iodine-doped bismutite (Bi₂O₂CO₃) components were successfully in situ synthesized by a one-pot hydrothermal method. Characterizations such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) demonstrated iodine was favorably doped into the Bi₂O₂CO₃ component, of which the {001} facets grew in situ from {002} facets of g-C₃N₄ for the heterostructure construction of I-doped Bi₂O₂CO₃/g-C₃N₄ (IB/CN). The photocatalytic activity of catalysts was evaluated by the degradation efficiency of 1,5-dihydroxynaphthalene under visible light. 1.5-IB/CN with a reasonable iodine doping amount (Bi: I molar ratio = 1.0: 1.5) exhibited the superior photodegradation performance compared to Bi₂O₂CO₃, achieving an 85.5% removal ratio after 100 min illumination. The enhanced activity of 1.5-IB/CN was attributed to both of the heterostructure that promoted the separation of photoinduced carriers and iodine doping that tuned the bandgap for sufficient visible-light harvesting. The degradation intermediates of 1,5-dihydroxynaphthalene in the system were determined and its possible photodegradation pathway was proposed in detail. This study provides a rational approach for enhancing the visible-light catalytic activity of wide-bandgap Bi₂O₂CO₃, and reveals a new perspective on the removal mechanism of organic pollutants.

Thermal hazards of benzoyl peroxide and its derived process products through theoretical thermodynamics assessment and different calorimetric technologies

Benzoyl peroxide (BPO) is one of the primary OPs used as an initiator, curing agent, or medicine. Some of the plastic processes use BPO without air for maintaining the efficiency of the entire reaction. However, there have been numerous accidents involving BPO in petrochemical plants, especially those related to fire and explosion, that are due to its unstable thermal properties and peroxy bond (OO). BPO can be identified as a typical substance with autocatalytic reaction characteristics. Therefore, the related processes and their products are critical to prevent these kinds of chemical contingencies. This research was based on two types of instruments (nonisothermal and isothermal calorimetry), and theoretical methods to further determine the thermal hazard level. From the experimental results for BPO and BPO mixed with its by-products, the heat of decomposition was much higher (from 800 to 1235 J/g), the time to maximum rate under isothermal conditions was much shorter (from 99.1 to 17.4 h at 75.0 °C), and the apparent activation energy was much lower (from 118 to 91 kJ/mol) after BPO was mixed with its by-products. Therefore, the hazard level of BPO mixed with its by-products from the reaction process was much higher than that of pure BPO.