Hydrodeoxygenation, decarboxylation and decarbonylation reactions while co-processing vegetable oils over NiMo hydrotreatment catalyst. Part II: Thermal effects - Experimental results

Two paraffinic feedstocks containing 20 vol.% of significantly different vegetable oils (olive or corn oil) were subjected to hydroconversion over a commercial NiMo catalyst under two different pressures (3.0 or 6.0 MPa), at 320 degrees C, with liquid hourly space velocity (LHSV) of 1.0 h (1) and hydrogen/feedstock ratio equal to 300 N m(3)/m(3). Changes in the hydroconversion pressure significantly affect the contribution of the major (hydrodeoxygenation, decarboxylation and decarbonylation) and secondary reactions (strongly exothermic methanation and endothermic reverse water gas shift reaction (rWGSR)). Nevertheless, the total heat effect in the reactor did not differ significantly. The heat effects changed noticeably when different vegetable oils were used as feedstocks. It was found that the differences in the total heat effects noted during hydroconversion for the two vegetable oils depend on the unsaturated fatty acid contents. (C) 2014 Elsevier Ltd. All rights reserved.