Operating conditions to maximize clean liquid fuels yield by oligomerization of 1-butene on HZSM-5 zeolite catalysts

The effect of operating conditions has been extensively studied for the selective oligomerization of 1-butene to clean synthetic liquid fuels. HZSM-5 zeolite (SiO2/Al2O3 ratio = 30-280) based catalysts provided with a hierarchical porous structure have been tested in a fixed bed reactor under the following conditions: 175-325 degrees C; 1.5-40 bar; space time, 0.5-6 g(catalyst).h mol(C)(-1). Special attention has been paid to individual and lumped gaseous and liquid product distribution (which have been characterized by gas chromatography, GC x GC/MS and simulated distillation), as well as to catalyst stability, by performing long duration experiments (20 h). An optimum region to maximize both naphtha (C5-11, >40%), and diesel (C(12-2)0, >20%) yields has been established at 250-275 degrees C and 30 bar for space time values of 2-4 g(catalyst) h mol(C)(-1). Furthermore, the catalysts have tended to a pseudo-stationary deactivation state after 5 h on stream, where the coke deposited on the spent catalysts is mainly composed of adsorbed bulky oligomers (determined by TPD-N-2), with low coke contents similar to 1.0-1.5 wt% (determined by TPO). (C) 2020 Elsevier Ltd. All rights reserved.