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The chemical recycling of waste plastics has become a research hotspot. However, in the chemical recycling process of the waste plastics containing chlorine, the chlorides are highly corrosive to the production equipment. This leads to the environmental pollution as well as a reduction in product quality. Through the analysis of the current relevant emission standards for chlorine content in our country, the development of dechlorination technology is recognized to be an important way to improve the chemical recycling process of waste plastics. At present, the domestic and foreign dechlorination technologies mainly include sorting, machinery, solvent dechlorination, step-by-step thermal decomposition, adsorption, and catalysis technologies. The characteristics, reaction mechanisms, and industrial applications of various dechlorination technologies were introduced in detail. Moreover, the advantages and disadvantages of each technology were analyzed and compared. A combined dechlorination technology was proposed to accelerate the development of chemical recovery process of chlorine-containing waste plastics. [ABSTRACT FROM AUTHOR]

Mineral matters are essential components of coal and significantly affect its thermal conversion process. To investigate the effects of the minerals on the structures and pyrolysis behaviors, three middle/low-rank Xinjiang coals were mildly pretreated with a weak organic acid with low concentration. We evaluated the physicochemical properties and mineral matters of raw and acid-pretreated coals and analyzed their pyrolysis behaviors. The results indicated that the chemical structure of coals changed slightly; their physical pore structure enlarged; the content of metal cations decreased obviously. The minerals are adverse to conducting the depolymerization and decomposition reaction at the temperature lower than 300 °C. With the temperature increasing, the minerals exhibit excellent catalytic performance and reduce the release of gaseous products (H2O, CO2, H2, C1~C3) mainly from the polycondensation and secondary reaction. The coal rank and the content of coal ash could affect the catalytic performance. [ABSTRACT FROM AUTHOR]