Novel Incineration Technology Integrated with Drying, Pyrolysis, Gasification, and Combustion of MSW and Ashes Vitrification

Abstract

The conventional mass burn systems for municipal solid waste (MSW) emit large amount of acidic gases and dioxins as well as heavy metals due to the large excess air ratio. Additionally, the final process residues, bottom ash with potential leachability of heavy metals and fly ash with high level of heavy metals and dioxins, also constitute a major environmental problem. To deal with these issues more effectively, a novel MSW incineration technology was developed in this study. MSW drying, pyrolysis, gasification, incineration, and ash vitrification were achieved as a spectrum of combustion by the same equipment (primary chamber) in one step. In practice, the primary chamber of this technology actually acted as both gasifier for organic matter and vitrifying reactor for ashes, and the combustion process was mainly completed in the secondary chamber. Experiments were carried outto examine its characteristics in an industrial MSW incineration plant, located in Taiyuan, with a capability of 100 tons per day (TPD). Results showed that (1) the pyrolysis, gasification, and vitrification processes in the primary chamber presented good behaviors resulting in effluent gases with high contents of combustibles (e.g., CO and CH4) and bottom ash with a low loss-on-ignition (L.o.l), low leachability of heavy metals, and low toxicity of cyanide and fluoride. The vitrified bottom ash was benign to its environment and required no further processing for its potential applications. (2) Low stack emissions of dioxins (0.076 ng of TEQ m(-3)), heavy metals (ranging from 0.013 to 0.033 mg m(-3)), and other air pollutants were achieved. This new technology could effectively dispose Chinese MSW with a low calorific value and high water content; additionally, it also had a low capital and operating costs compared with the imported systems.

Polycyclic aromatic hydrocarbons (PAH) formation from the pyrolysis of different municipal solid waste fractions

“…The products of pyrolysis and gasification (oil, char and syngas) allow for a broad range of applications e.g. electricity and heat production from combustion of syngas gas; chemicals and transportation fuels extracted from liquid pyrolysis oils (Liu and Liu, 2005;Hanaoka et al, 2005). In the process of pyrolysis and gasification, thermal-decomposition of the raw materials (pyrolysis) is considered to be a fundamental process (Zhou et al, 2013).…”

Performance of a Semi-Industrial Scale Gasification Process for the Destruction of Polychlorinated Biphenyls

“…For example, lower-limit levels of 0.001 ng/m 3 TEQ have been reported in the gasification of highly chlorinated feedstocks, 6 and the presence of OCDD in flue gas from the gasification of municipal solid waste has been reported at 0.17 ng/m 3 (at 11% O 2 ). 34 The destruction and removal efficiency, with respect to the total amount of PCBs fed, was Ն1 order of magnitude above the minimum allowable.…”

“…In fact, the fate is the same for other organic compounds. Other authors have demonstrated or documented that gasification of chlorinated solvents 33 and, in general, municipal solid waste 34 and hazardous waste, is feasible, 6 and in theory such compounds, like chlorofluorocarbons and pesticides, could also be treated by this technology.…”

Fate and Distribution of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in a Woodchip-fuelled Boiler

“…The sampled flue gas volumes were normalized to the dry condition of 760 mmHg and 273 K, and denoted as Nm 3 . The collection time for each stack flue gas sample lasted for about three hours, although in other study (Liu and Liu, 2005), it lasted for 8 hours. To obtain representative samples, the feeding woodchips, bottom residues, and fly ashes from the cyclone and bag filter were sampled simultaneously with the stack flue gas samples.…”