Abstract: The 1.2 Mt/a MaxEne unit of SINOPEC Yangzi Company was successfully start-up and put into operation on January 23, 2013. The function of MaxEne is to isolate n-alkanes from naphtha by simulated moving bed (SMB) process. The extract oil is used as the feed of steam cracking unit to produce ethylene. The raffinate oil is used as the feed of catalytic reforming unit. The commercial results showed that the n-alkanes purity was 94.83％ in the extract oil, and the recovery rate of n-alkanes was 87.02％, based on mass fraction of n-alkanes of 26.25% in naphtha. With the use of the extract oil as the feed of ethylene cracking, the ethylene yield increased by 14.10 percentage points and the aromatic potential content of the raffinate oil increased by 11.20 percentage points compared with the results of naphtha fraction as feedstock. The reasons for the periodic fluctuation of the raffinate column, the high consumption of desorbent and the flooding of the extract column were analyzed.

Key words: naphtha, n-alkane, adsorption separation, steam cracking, ethylene, catalytic reforming