Effect of normal paraffins separation from naphtha on reaction kinetics for olefins and aromatics production

• A naphtha separation scenario via SMB was studied in a petrochemical complex.
• 83 chemical reactions of naphtha thermal cracking were proposed.
• 86 chemical reactions of naphtha catalytic reforming were proposed.
• Separation of n-paraffins from naphtha increased the olefins production by 14%.
• Separation of n-paraffins from naphtha increased the aromatic production by 11%.

The objective of this study is to investigate the effect of the normal paraffins (n-paraffins) separation by the simulated moving-bed (SMB) on reaction kinetics of the naphtha thermal cracking (NTC) and catalytic reforming (NCR) for the olefins and aromatics production, respectively. First a process simulation of the SMB unit integrated to the petrochemical complex (PCC) was performed. Chemical reaction kinetics of NTC and NCR were proposed and validated. And a retrofit PCC with the SMB unit (rPCC) was compared to a conventional PCC (cPCC) in terms of products composition, flow rate, and energy consumption. It was found that olefins and aromatics yields of NTC and NCR can increase by 14 wt% (41 kt/yr) and 11 wt% (127 kt/yr) for the naphtha capacity of 2475 kt/yr, respectively. However, the total energy consumption of rPCC increased by about 67.8 MW (or 25%) because of the desorbent recovery in the SMB unit.