Supercritical Extraction/Liquid-Phase Oxidation of Wastes

摘要

During the experimental program, IGT conducted a series of laboratory-scale211u001esupercritical CO extraction tests to evaluate the effects of CO flow rate, 211u001etemperature, and the addition of a modifier on the extraction of polynuclear 211u001earomatic hydrocarbons (PAHs) from soil. The laboratory-scale tests were conducted 211u001ewith supercritical CO in once-through mode. The bench-scale tests were conducted 211u001ein CO recirculation mode with activated carbon absorption of the PAHs. Overall, 211u001ethe results of these tests show that the extent of PAH extraction from soil 211u001eincreases with temperature to a maximum at about 65 deg. At temperatures above 65 211u001edeg. the extent of PAH extraction from soil increases with temperature to a 211u001emaximum about 65 deg. the extent of PAH extraction decreases. In PAH absorption 211u001etests with activated carbon, the results showed that lower, rather than higher, 211u001etemperatures of the activated carbon increased the capture of PAHs from 211u001esupercritical CO. A temperature of about 45 deg. showed that a concentration of 211u001ethree percent yielded the highest PAH extractions in the range of methanol 211u001econcentrations, up to 10 percent in CO.