Study on delacquer used beverage cans by vacuum pyrolysis for recycle.
So far, conventional processes that have been employed to delacquer the paints decorated on used beverage cans (UBCs) are less than satisfactory in economic and environmental effect. Therefore, a new method combining vacuum pyrolysis with dilute sulfuric acid leaching to delacquer the paints was investigated. The results of vacuum pyrolysis showed that the decoating rate increased with the increase of temperature and the paints were almost 100% removed from UBCs under the following conditions: temperature of 650 °C, holding time of 20 min, and residual gas pressure lower than 0.1 kPa. The pyrolysis oil was mainly composed of phenol and 2-methy-phenol analyzed by GC-MS. The delacquered UBCs were subsequently leached with 5% H2SO4 for 60 s and TiO2 was recovered by calcining the residuals in muffle furnace at 450 °C for 15 min. This innovative technology offers an effective method to delacquer paints from UBCs, which obtains excellent stripping effect and avoids the production of toxic substances generated in direct combustion process. Furthermore, the pyrolysis oil can be reused as chemical feedstock in other fields.
College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, Hunan, China.
Ning
N
Li
Keqiang
K
Qiu
D001628:Beverages; D007764:Lacquer / Q000032:analysis*; D059027:Recycling / Q000379:methods*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013464:Sulfuric Acids / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014618:Vacuum; D014961:X-Ray Diffraction
D012996:Solutions; D013464:Sulfuric Acids; C033158:sulfuric acid