Chlorine Removal Mechanism from Municipal Solid Waste Using Steam with Various Temperatures

Abstract

With a goal to develop a suitable refuse derived fuel (RDF) manufacturing process, organic and inorganic chlorine removal from RDF was investigated by using steam with various temperatures. For organic chlorine pyrolysis, steam temperature was changed from 463 to 573 K. For inorganic chlorine removal by steam condensation, steam temperature was fixed at 373 K. The pyrolysis kinetics of organic chlorine increased with an increase in superheated steam temperature, whereas the chlorine emission kinetics increased with an increase in sample temperature. Part of the pyrolyzed organic chlorine changed to inorganic chlorine. Organic chlorine decreased more rapidly than a decrease in dry matter yield, but inorganic chlorine increased with a decrease in dry matter yield above 0.8, which indicated that the decreasing ratio of total chlorine was roughly as large as that of dry matter yield. Removal ratio of inorganic chlorine increased with an increase in steam condensation because inorganic chlorine was dissolved in a water droplet.

Effect of granulation on chlorine-release behavior during municipal solid waste incineration

“…Dai et al 18 achieved a 90% reduction in chlorine release at 1000 °C by adding MgCO 3 with 10% of the total waste mass consists.PVC: (CH 2 CHCl) n → n HCl + n C 2 H 2 NaCl: 2NaCl + SO 2 + 0.5O 2 + H 2 O → Na 2 SO 4 + 2HClNaCl: 2NaCl + H 2 O + m SiO 2 → Na 2 O· m SiO 2 + 2HClIn summary, the previous studies have primarily focused on chlorine release characteristics during RDF combustion, with factors such as temperature, time, waste composition, and additives being considered. 19–23 However, there is a lack of research on the impact of RDF particle granulation on chlorine release. The MSW without granulation is loose and the contact between components is insufficient, resulting in the low conversion rate of some solid–solid reactions and gas–solid reactions.…”

“…In summary, the previous studies have primarily focused on chlorine release characteristics during RDF combustion, with factors such as temperature, time, waste composition, and additives being considered. [19][20][21][22][23] However, there is a lack of research on the impact of RDF particle granulation on chlorine release. The MSW without granulation is loose and the contact between components is insufficient, resulting in the low conversion rate of some solid-solid reactions and gas-solid reactions.…”

Simultaneous degradation and dechlorination of poly (vinyl chloride) by a combination of superheated steam and CaO catalyst/adsorbent

“…Superheated steam has an excellent heat transfer property due to the addition of radiation heat transfer compared with heated air and nitrogen, and the treatment under ordinary pressure permits to reduce the operating cost relatively. It was successfully 6 applied to the dechlorination treatment of municipal solid waste (MSW) [42,43] and incineration ash [44]. Fonseca et al [45] investigated the effect of mixed gas of superheated steam and nitrogen without catalyst/adsorbent on the dehydrochlorination of PVC resin and indicated that the dehydrochlorination rate increased from 61 % (100 vol% nitrogen) to 77 % (50 vol% superheated steam -50 vol % nitrogen) at 523 K by adding superheated steam in nitrogen gas.…”

Dechlorination of Polyvinyl Chloride under Superheated Steam with Catalysts and Adsorbents

“…On the other hand, some of the authors carried out the dechlorination of refuse-derived fuel (RDF), , chlorides in incineration ash, and the carbonization of biomass by superheated steam, which has gained much attention as a result of the simplicity of the equipment and the higher heat transfer property. The effects of superheated steam on the dechlorination and the additives were not clear in these studies.…”