No abstract

No abstract

No abstract

Retorting is a frequently used method for producing shale oil from oil shale. During retorting, heat is usually supplied to the retort by heat-carrier gas of high temperature, such as 700 °C, until retorting ends. In this work, a low-energyinput retorting process using low-temperature carrier gas but without marked loss in oil yield was achieved by a self-heating effect, that is, spontaneously increasing retorting temperature in the absence of external heat provision. The self-heating retorting process starts by preheating oil shale from room temperature to 300 °C by external heating under N 2 and then switching N 2 to air of 150 °C. When N 2 is replaced by air, the self-heating effect starts. Subsequently, the temperature of raw oil shale can increase spontaneously to complete the retorting, so that an external heat supply is no longer required. While using only N 2 or only air as the carrier gas throughout the whole retorting process cannot produce such a good effect. In this N 2 -air sequence retorting process, because an external heat supply is needed only to preheat the raw oil shale to 300 °C (i.e., the required energy input and external-heating terminal temperature are low), the retorting process is significantly simplified. The present work provides a promising starting point for the further development of not only ex situ (aboveground) but also in situ (underground) retorting for the production of shale oil.

No abstract

No abstract

No abstract

BACKGROUND: The binary benzene-n-propanol azeotrope can be formed in chemical production. Extractive distillation is an important azeotrope separation technology and an ionic liquid is a type of excellent entrainer. Aspen Plus software was used to simulate the extractive distillation process. The separation performance of ionic liquids was evaluated in terms of total annual cost of the extractive distillation process. The separation mechanism of the azeotrope was quantitatively explained using intermolecular interaction energy. RESULTS: The thermodynamic properties databases of 1-octyl-3-methylimidazolium acetate, trioctylmethylammonium acetate and 1-decyl-3-methylimidazolium acetate were established in Aspen Plus software. The extractive distillation process was established through combining the thermodynamic properties of the three ionic liquids and the vapor-liquid equilibrium data of benzene-n-propanol-ionic liquid. The optimal operating conditions were obtained by minimizing the total annual cost of the separation process through a sequential iterative method. The interaction energy was calculated using density functional theory through Gaussian 09 software and used to explain the principle of the benzene-n-propanol azeotropic system separation.CONCLUSIONS: 1-Octyl-3-methylimidazolium acetate has the best separation performance among the three ionic liquids. The interaction energy can be used to screen and design ionic liquids in the process of benzene-n-propanol extractive distillation separation.