Effect of Normal Paraffin Content on Ethylene Yield and Feedstock Allocation of Ethylene Pyrolysis Process

The technology of separating normal paraffins from the naphtha through the adsorption process was studied to optimize the steam cracking feedstock and utilize the naphtha resource properly.The raffinate oil without normal paraffins could be used as quality feedstock of catalytic reforming process or blending component for high-octane clean gasoline.The desorption oil with the normal paraffin content above 98.2% was used as quality feedstock of ethylene pyrolysis process.In the typical industrial operational conditions,compared to the process with the naphtha feed,the gas yield increased from 85.8% to 96.1%,and the ethylene yield increased from 31.4% to 47.2%.The total yield of ethylene,propylene and butadiene rose from 52.1% to 65.9%.Effect of normal paraffin content on the yield of ethylene,propylene and butadiene was studied and the correlation equation was gained.The optimized utilization of the naphtha resource coupling with the steam cracking and catalytic reforming processes was discussed;the partial adsorption scheme using desorption oil and naphtha mixture as the cracking feed was investigated.The simplified adsorption process without the intermediate oil step was also described.