Variations in the pore structure of oil shales during retorting and combustion

Evaluation of the porous structure of Huadian oil shale during pyrolysis using multiple approaches

“…The re-solidification of bitumen and the formation of porous thermoplast will result in pore mouth blockage and a dense structure. This reduces the accessibility of the nitrogen molecules during the adsorption process (below 400°C) [13].…”

“…Burnham [12] investigated the reaction kinetics between CO 2 and residual carbon from Colorado oil shale using Hg porosimetry and BET measurements and estimates a surface area of a few hundred m 2 g À1 in the context of understanding gasification rates, the result that oil shale residual carbon is approximately an order of magnitude more reactive than subbituminous-coal char although the surface areas are similar. Schrodt and Ocampo [13] reported that a high pyrolysis temperature and a rapid heating rate were favorable for the evolution of the pore structure. However, Bai et al [14] reported that a rapid heating rate may inhibit the development of the pores.…”

Experimental study and isotherm models of water vapor adsorption in shale rocks

“…The type Ⅱ isotherm is very common in a non-porous or a macro-porous adsorbent, where multilayer adsorption occurs at the high relative humidity (Schrodt and Ocampo, 1984;Rouquerol et al, 2014). The isotherm is concave at the low relative humidity, then nearly linearly increasing, and finally convex to the p/p 0 axis.…”

Heat transfer characteristic of oil shale particle during the retorting

“…The formed volatiles flow out through the pores within the particle and thus have a negative effect on the heat transfer to the inner of the particle. Along with the pyrolysis process, the pores of the solid particle become larger and some new pores open [20,21], providing more passages for the gaseous products and favoring their interaction with the heated solid parts. Consequently, in this stage, the heat transfer inside the particle follows such models: (a) conduction inside the solid particle, (b) convection and radiation inside the fracture pores.…”