Record Details
Field | Value |
---|---|
Title | The extraction of pentachlorophenol from pressure treated wood using supercritical carbon dioxide |
Names |
Yi, Jung-Seok
(creator) Levien, Keith L. (advisor) |
Date Issued | 1993-11-30 (iso8601) |
Note | Graduation date: 1994 |
Abstract | The extraction of pentachlorophenol (PCP) from pressure treated wood wafers with supercritical carbon dioxide has been studied. Experimental data were obtained for the effects of pressure (17.5 - 25.0 MPa), temperature (313 - 353 K), flow rate (1 - 3 ml/min at supercritical conditions), and sample size (0.8 x 10 x 50 mm and 2.2 x 10 x 50 mm) by measuring the effluent concentration versus time. A fundamental model was developed which includes rates of intraparticle diffusion, external film mass transfer, desorption and the initial distribution of PCP between the pore volume (cell lumen) and pore surface (cell wall) of wood wafers. The intraparticle diffusion and external mass transfer rates are combined in terms of an overall mass transfer coefficient derived from the assumption of a parabolic concentration profile of PCP inside the wafer pores. The initial distribution of PCP between cell lumen and cell wall was determined by fitting the mathematical model to dynamic extraction rate data. The desorption rate was very small for all the extraction conditions, and extraction rate increased with the pressure, temperature, and flow rate because the combined mass transfer increased. Similar values of mass transfer coefficient were achieved for two different sample sizes: 0.8 x 10 x 50 mm and 2.2 x 10 x 50 mm. |
Genre | Thesis/Dissertation |
Topic | Supercritical fluid extraction |
Identifier | http://hdl.handle.net/1957/37192 |