响应面分析法优化掺炼乙烯裂解焦油的延迟焦化研究

RESEARCH ON OPTIMIZING DELAYED COKING PROCESS WITH ETHYLENE TAR BLENDED FEED BY RESPONSE SURFACE METHODOLOGY

研究了减压渣油掺炼乙烯裂解焦油的延迟焦化工艺。采用响应面分析法确定了对延迟焦化液体收率影响显著的因素,并获得延迟焦化掺炼乙烯裂解焦油的优化工艺条件,即焦化反应温度517℃、掺炼比20%、焦化反应时间175 min。在此工艺条件下,液体收率可以达到74.1 6%,比单独采用减压渣油为延迟焦化原料时增加7.49个百分点。掺炼乙烯裂解焦油后,在焦化汽油馏分中,正己烷等直链饱和烃类含量增加,芳香烃类的含量有所增加,而正壬烷等直链饱和烃类含量有所减少;焦化柴油中的饱和烃类含量基本不变,而芳香烃含量增加,尤以中芳烃含量的增加最为明显(增加19.42个百分点),胶质含量减少6.66个百分点。

For increasing the liquid yield of delayed coking process and reasonably utilizing the ethylene tar resource,delayed coking process using vacuum residue blended with ethylene tar is studied. Response surface methodology is used to determine the factors influenced the liquid yield of delayed coking process,and the optimal process conditions are obtained as follows： an ethylene tar blended ratio of 20% ,a reaction temperature of 517 ℃ and a reaction time of 175 min. As compared to the delayed coking process without blending ethylene tar, under the optimal process conditions the liquid yield reaches 74.16 %, which is 7.49 percentage points higher. Besides, since blending ethylene tar in feed, in coker gasoline the contents of n-hexane and aromatics increase, while the content of n-nonane decreases; in coker gas oil the content of saturated hydrocarbons remains the same, the content of aromatics increases, esp. the content of medium aromatics increases significantly （an increment of 19.42 percentage points）, the resin content reduced 6.66 percentage points.