Investigation on a novel preparation process of B-COPNA resin from catalytic cracking diesel

Abstract

As one of main products in fluid catalytic cracking unit, catalytic cracking diesel (light cycle oil, LCO) has inferior combustion performance, improper to be used as vehicle diesel. Condensed polynuclear aromatic resin of moderate condensation degree (B-COPNA) has a wide range of application prospects, but is seriously limited by the manufacturing cost. A novel process was proposed to convert polycyclic aromatic hydrocarbons in LCO into B-COPNA resin using PXG and PTS as crosslinking agent and catalyst, respectively. The composition of LCO was analyzed first, and the effects of operating conditions such as reaction temperature, reaction time, crosslinking agent and catalysts content on the viscosity and yield of B-COPNA resin were investigated to optimize the process. The molecular structure of B-COPNA resin is characterized by FT-IR spectra, NMR spectra, TOF-MS and elemental analysis. The combustion performance of LCO and the heat resistance of B-COPNA were evaluated and compared. The result shows that LCO is rich in aromatic hydrocarbons with 2-3 rings, making it an ideal raw material for COPNA resin. The optimized conditions of preparation experiments were 240 °C, 5 h, 1:1.8 (PXG:LCO) and 3 wt% of catalyst content with a B-COPNA resin yield of 67.2%. After the crosslinking reaction, the heat resistance temperature of B-COPNA resin product was up to 417 °C, while the cetane value of LCO increased to 43.6, an increase of 42.95%. Hence, it was confirmed that the current process can achieve a high value-added utilization of LCO by converting into B-COPNA resin, which has a superior combustion to bring extra high economic value to petrochemical industry.