Dispersion effects of Ni2P catalysts on hydrotreating of light cycle oil

摘要

A series of Ni2P/SBA-15 catalysts with different Ni2P loadings were prepared and applied for the hydrotreating of light cycle oil. The loading level of Ni2P was varied from 0.5 to 3.0 mmol Ni2P per 1.0 g of SBA-15 support, resulting in the optimum catalyst loading of 2.0 mmol Ni2P. The physical properties of the catalyst samples were characterized by N2-adsorption-desorption isotherms, CO uptake chemisorption, TPR, and TEM. X-ray diffraction (XRD) and extended X-ray absorption fine structure (XAFS) spectroscopy were used to obtain structural properties for the supported Ni2P catalysts. Hydrotreating tests were performed in a continuous flow fixed-bed reactor at 623 K, 3.0 MPa, and LHSV's of 0.5-1.0 h~(-1). The 2.0 mmol Ni2P/SBA-15 gave an HDS conversion of 99.0% and an HDN conversion of 92.5%, which were much higher than those of a Ni-Mo-S/Al2O3 catalyst which gave an HDS conversion of 91.9% and an HDN conversion of 65.8% based on the same LHSV of 0.5 h~(-1). Substantial changes in the composition of aromatic compounds were found for the Ni2P/SBA-15 catalysts from 14.3 wt.% 1-Ar (mono-arorhatics), 40.6 wt.% 2-Ar (di-aromatics) and 19.4 wt.% ~(3+)-Ar (tri*-aromatics) in the LCO feed to 46.1 wt.% 1-Ar, 16.3 wt.% 2-Ar and 2.0 wt.% ~(3+)-Ar in the product.