Non-catalytic and In-situ catalytic co-pyrolysis of Huadian oil shale and microalgae using several additives as catalyst.

The non-catalytic and in-situ catalytic co-pyrolysis of Huadian oil shale (OS) and microalgal powder (MP) were performed using a modified aluminum retort. By comparing the product yields and compositions for non-catalytic and catalytic pyrolyses, the catalytic effect of several additives, including MgO, CaO, ZrO 2 , Al 2 O 3 , zeolite Y, and zeolite ZSM-5, was investigated. This study focused on the deoxygenation performance of the pyrolytic oil. The oil yield increased with increasing MP addition in non-catalytic co-pyrolysis trials. At the OS/MP blending ratio of 3/1, the oil yield was 12.42 wt %, and the oxygen content and H/C ratio of oil were 11.54 wt % and 1.571, respectively. Both CaO and Al 2 O 3 significantly decreased the oxygen content of the oil to <7 wt % with less oil loss (<1 wt %). CaO catalysis facilitated the dehydrogenation of free radicals to release H 2 , thereby increasing alkene formation and decreasing the H/C ratio of the oil to 1.441. Al 2 O 3 catalysis increased the H/C ratio to 1.656 and improved the oil quality. ZSM-5 preferentially catalyzed the reaction between n -alkenes and nitrogenates to yield nitriles, and the catalytic performance for deoxygenation was negligible. Hence, Al 2 O 3 was selected as the most suitable additive for the co-pyrolysis of OS and MP. • CaO and Al 2 O 3 decrease the oxygen content of the oil with less oil loss. • CaO facilitates the dehydrogenation of free radicals to release H 2. • Al 2 O 3 increases the H/C ratio of the oil and improved the oil quality. • ZSM-5 catalyzes the reaction between n-alkenes and nitrogenates to yield nitriles. [ABSTRACT FROM AUTHOR]