Dissolution Rate of Oil Shale Thermobitumen in Different Solvents

Abstract

Dissolution kinetics of the mix of thermobitumen and oil (TBO) formed at lowtemperature pyrolysis of oil shale in autoclaves was studied for the first time. The pyrolysis temperature was varied in the range of 350-370 °C and duration between 3 and 9 hours. The dissolution of TBO obtained was conducted in a thermostated stirred class reactor and evaluated by the increase in optical density of the solutions with time varying temperature (25-60 °C) and solvent type (benzene, toluene, oil shale petrol and ethanol). A mathematical model was deduced for quantitative description of dissolution kinetics by approximation of the process to the first-order parallel dissolution of two fractions. The dissolution rate coefficients for the fractions were estimated, and contribution of their partial optical densities on the current optical density was described under the conditions studied.

Kinetics of kukersite low-temperature pyrolysis in autoclaves

“…The time dependence of temperature (T) in 8C was calculated for definite (20 min) time intervals according to the modified in [22] equation taken from [24] T t ¼ T nom À ðT nom À T room Þ expðÀbtÞ (15) where the heating rate characteristic b, in 1/min, for the autoclave applied was found from the empirical polynomial relationship b ¼ 60 0:0001T 2 nom À 0:4073T nom þ 887:57 (16) The values of the rate coefficients at every mean temperature of the time intervals were calculated introducing the corresponding kinetic constants from Table 3 into the exponential form of Eq. (14).…”

“…In an our previous paper [22] a mathematical model was proposed to describe the co-effects of time and temperature on the oil shale pyrolysis kinetics under conditions of non-linear increase of temperature in autoclaves at nominal temperatures 420-500 8C. An approach was proposed where the pyrolysis process was handled consisting of two separate stages.…”