Abstract: Based upon the principle of “producing the products according to feedstock features”, n-paraffins are separated from i-paraffin to realize the optimal utilization of light naphtha raw material. The light naphtha,which is rich in i-paraffin components with high octane number,is used as the gasoline blending component to increase the octane number and to improve the octane distribution of the gasoline pool. The light naphtha with more n-paraffin component can be used as steam cracking feedstock to increase the ethylene yield. In the case of insufficient octane number of the gasoline pool of the factory，the implementation of i/n hydrocarbons separation is very helpful to increase the octane number of the gasoline pool and the output of high-octane gasoline，and at the same time, increase the yield of ethylene products. Taking a refinery as an example, the implementation of the i/n-paraffin separation greatly improved the economic benefits. Based on the Brent crude oil price of $60 /bbl（1 bbl=159 L）in 2019, the revenue of gasoline and olefins products can be increased by RMB739.64 million per year. After deducting the increase of fuel power cost and auxiliary material cost of 76.74 million Yuan/a, the net income of the project is 662.9 million Yuan /a.

Key words: light naphtha, optimal utilization, gasoline blending, steam cracking