Improved separation and utilization of light naphtha stock by adsorption process

An integrated process for separation and utilization of light naphtha stock in refineries is discussed in this paper. Normal paraffins present in light naphtha streams are first separated from nonnormal paraffins by adsorption technology. The adsorbed n-paraffins are recovered and can be used as an ideal feedstock for steam cracking, meanwhile iso-pentane or iso-pentane and iso-hexane blends are recovered by rectification of the nonadsorbed effluent and used as necessary components for modern gasoline or aviation gasoline products. From the results for a model feedstock, an isothermal adsorption and purging desorption approach is selected. Optimum parameters consist of adsorption and desorption duration of 30 min at 180℃ for each, nitrogen stream LHSV of 240 h−1 in the desorption step, the dynamic capacity of the adsorbent reaches 0.042 g/g.