| 摘要 |
PROBLEM TO BE SOLVED: To safely and economically remove PCB of waste paper of supercritical extraction method. SOLUTION: Waste paper 1 is torn and supplied to an extraction container 2. Carbon dioxide 4 and an entrainer 7 are pressurized by pressure pumps 6, 8 and supplied to the extraction container 2 and the waste paper 1 is stirred by a stirring apparatus 10. The temperature of the inside of the extraction container 2 is kept at the critical temperature of carbon dioxide or higher and the pressure of the container is kept at the critical pressure or higher to keep the carbon dioxide in supercritical state and consequently, PCB contained in the waste paper 1 is dissolved and extracted. Since the entrainer 7 has a function of heightening the affinity of the supercritical carbon dioxide and PCB, the extraction efficiency of PCB is further improved. The supercritical carbon dioxide in which PCB is dissolved extracted discharged out of the extraction container 2, led to a separation container 14, and cooled and pressure- decreased to the critical temperature or lower and the critical pressure or lower to separate and collect PCB.
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