Coupled recycling of PVC and glass wastes producing chlorine-free fuels and cement feed stock.
To utilize PVC and glass wastes in a landfill, a kinetic study was conducted for neutralization of HCl derived from PVC pyrolysis with sodium in soda glass. The effective diffusion coefficient of sodium at 550 degrees C was 3.3 x 10(-16) m2/s in steam atmosphere, but was 1.2 x 10(-17) m2/s in dry atmosphere. It was confirmed from experimental results in which considerable NaCl crystals were deposited on the surface of glass particles after 6 h reaction with particles of 25 microm in diameter that NaCl crystals' growth on the glass surface does not affect the neutralization rate rate in our experimental conditions. The effect of hydrothermal treatment was studied for the glass treated at 250 degrees C under a vapor pressure of 3.6 MPa for 5 h. Approximately 20 times higher rate than that of original glass was caused by the formation of the porous surface layer through which sodium ions can readily diffuse out The effect was not clear until steam pressure reached the above value. The absence of chlorine within the glass matrix was confirmed by EDS analysis on the cross section of glass cullets reacted with HCl gas. Neutralization of HCl gas with soda-glass conducted under steam atmosphere to increase the reaction rate is effective to recover energy and material from PVC and glass wastes.
Sung
Ho-jin
HJ
Plant Engineering Center, Institute for Advanced Engineering, Woncheon-dong, Yeongtong-gu, Suwon-si, Gyeonggi-do, 443-749, South Korea. hjsung@iae.re.kr
Noda
Reiji
R
Horio
Masayuki
M
D001272:Atmosphere; D002713:Chlorine / Q000737:chemistry*; D003247:Conservation of Natural Resources; D003460:Crystallization; D004058:Diffusion; D004602:Elements; D005742:Gasoline; D005898:Glass / Q000737:chemistry*; D007477:Ions; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D011143:Polyvinyl Chloride / Q000737:chemistry*; D012964:Sodium / Q000302:isolation & purification; D012965:Sodium Chloride / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D014866:Waste Products
D004602:Elements; D005742:Gasoline; D007477:Ions; D014866:Waste Products; D012965:Sodium Chloride; D002713:Chlorine; D011143:Polyvinyl Chloride; D012964:Sodium