Fuel Processing Technology, Vol.77-78, 365-372, 2002
Influence of sorbent characteristics on the adsorption of PAC II. Adsorption of PAH with different numbers of rings
The aim of this work was to relate sorbent textural characteristics with the adsorption capacities of two-, three- and four-ring polyaromatic hydrocarbons at the conditions emitted during energy generation, The sorbent textural parameters, total micropore volume, V-N2, narrow micropore volume, V-CO2, mesopore volume, V-BJH, and the free active sites were analysed trying to correlate them with their Np, Phe and Py adsorption capacities. To get this aim, single- and multiple-lineal regressions (MLR) were applied to the three studied polycyclic aromatic hydrocarbons (PAH), A principal component analysis was performed to generate new and uncorrelated variables. The relations between the textural parameters were analysed using a principal components regression (PCR). The PCR analysis had a good statistical quality, but it did not allow differentiating free active site types nor V-N2 and V-CO2. The correlations were, thus, set up applying a multiple-linear regression to the original variables (MLR). The regression statistical quality was similar to the PCR analysis and it could give an easier explanation of the parameters that affected the adsorption. In the Np adsorption. the 60% data variance was explained and the adsorption was positively cot-related to V-CO2 and the micropore mean diameter (L). In the Phe regression, the 86% variance was explained and its adsorption was positively correlated to V-N2 and the micropore distribution, n. In the Py adsorption, the 88% data variance was explained and this adsorption was positively correlated to V-N2 and V-BJH. These dependencies were according to the molecular parameters of these compounds, molecular diameter and volatility because the higher the aromatic cycles containing compounds, the more favoured the adsorbate-adsorbate interactions. Besides, the higher the mean diameter micropores, the lower the diffusion problems showed by Np. Phe and Py. (C) 2002 Published by Elsevier Science B.V.