Dynamic behavior of supercritical extraction of kerogen from shale

Abstract

A model is presented for the supercritical reaction-extraction of a solid component from a bed of porous particles through which the solvent flows. Accounted for are reaction at an intraparticle position, pore diffusion, interphase mass and heat transfer, and flow in a differential reactor. The behavior of the bed is dynamic since both temperature and concentration of extractable solid vary with time.The model is compared with experimental data for the extraction with toluene of kerogen from a bed of Colorado shale particles. Curves of effluent bitumen concentration vs. time were measured and fitted with predicted curves to evaluate three parameters: preexponential factor and activation energy for the conversion of insoluble kerogen to soluble bitumen, and the diffusivity of toluene at the critical point. The predicted curves agreed well with the experimental results and gave reasonable values for the parameters. Rates of reaction-extraction as well as extraction curves exhibited a sharp dip as the reactor was heated through the critical temperature.

Kinetics and mass transfer for supercritical fluid extraction of wood

“…The apparatus shown in Figure 1 is almost the same as used by Triday and Smith (1988) for the extraction of kerogen from oil shale and by Reyes et al (1989). The apparatus shown in Figure 1 is almost the same as used by Triday and Smith (1988) for the extraction of kerogen from oil shale and by Reyes et al (1989).…”

“…Since temperature significantly affects the concentration of extracted lignin derivatives, chemical reaction must be a principal concern in the overall process, as in the case of extraction of kerogen from oil shale (Triday and Smith, 1988). Since temperature significantly affects the concentration of extracted lignin derivatives, chemical reaction must be a principal concern in the overall process, as in the case of extraction of kerogen from oil shale (Triday and Smith, 1988).…”

“…Since the dead space in the tubing between the reactor and the detector for our apparatus contributed only to the time delay (Triday and Smith, 1988), the measured absorbance was corrected for this time. Differential-reactor operation was approximated because of the small bed size.…”

Phase equilibria for supercritical fluid process design

“…As a result, SCFE has been targeted as a means of upgrading coal, tar sands, lignite, and other fuels, mostly by pretreatment (Vasilakos et al, 1985;Pang and McLaughlin, 1985;Monge and Prausnitz, 1983;Scarrah, 1983;Chen and Kazimi, 1985). In these cases, higher-temperature fluids, such as tetrahydrofuran, toluene, benzene, the higher (up to dodecane) nparaffins, methanol, acetone or water, are required (Fong et al, 1983;Eisenbach et al, 1983;Amestica and Wolf, 1985;Penninger, 1985;Wilhelm and Hedden, 1985;Ross et al, 1987;Desh-pande et al, 1987;Kershaw and Bagnell, 1987;Triday and Smith, 1988). At these elevated temperatures, frequently above 4OO0C, both extraction and pyrolysis take place.…”

MODELING OF SPEARMINT OIL EXTRACTION IN A PACKED BED USING SC-CO2

“…Supercritical fluid extraction (SFE), particularly concerning the recovery of essential oils, is an attractive alternative to traditional separation methods such as steam distillation and solvent extraction, since thermal degradation and solvent contamination of the extract are avoided (McHugh and Krukonis, 1986). This technology has been recognized to be more effective and more expensive than conventional separation technologies, however, the operating cost is usually lower, and hence the total costs are comparable if the process is carried out at optimum conditions and sufficient extractor volume (Goodarznia and Eikani, 1998;Paulaitis et al, 1983;Rizvi et al, 1986;Sovova et al, 1994;Tan and Liou, 1988;Triday and Smith, 1988). In the previous decade, supercritical fluid technology has become popular due to its advantages when compared to conventional processes (Bimakr et al, 2011).…”