催化重柴油加氢后的催化裂解性能

Study on catalytic cracking performance of FCC heavy diesel after hydrogenation

催化重柴油芳烃含量高,加氢后仍难以作为车用柴油调和组分。对密度为934.0 kg/m3、芳烃质量分数为72.06%(其中双环芳烃质量分数为35.86%)的催化重柴油加氢前后的催化裂解性能进行研究。催化重柴油芳烃中以双环芳烃为主,通过加氢将其部分饱和得到环烷芳香烃,然后进行催化裂解,转化成汽油馏分芳烃和以烯烃为主的液化气。结果表明:加氢处理后的催化重柴油具有较好的裂解性能,柴油中的多环芳烃经加氢成为更易裂解的环烷芳香烃,有效减少了多环芳烃的含量,其裂解能力得到明显改善,转化率较催化重柴油直接裂解提高了19.09个百分点;产物中汽油收率增加16.60个百分点,且汽油中芳烃含量高(47.29%)、烯烃含量低(12.50%),是较好的高辛烷值汽油调和组分;液化气收率达到16.58%,其中丙烯、异丁烯在液化气中含量分别达到了42.70%和10.80%。

The catalytic diesel cannot be used as diesel blending fraction even after hydrogenation due to its high aromatic content.In this work,thecatalytic cracking performance of FCC heavy diesel（density of 934.0 kg/m^3,aromatic content of 72.06%and 2-ring aromatics content of 35.86%） before and after hydrogenation were investigated.The main aromatics in FCC heavy diesel are the 2-ring aromatics,which can be selectively transformed to naphthenoaromaticsvia hydrogenation and further cracked into aromatics in gasoline fraction and olefins in LPG through catalytic cracking.The results indicate that the cracking performance of hydro-treated diesel is substantially improved.The polycyclic aromatics are transformed to naphthenic hydrocarbons that can be easily cracking,and the conversion is 19.09% higher than the untreated diesel fraction.The gasoline yield is increased by 16.60% with high aromatic content（about 47.29%） and low olefin concentration（about12.50%）,which is a good high-octane gasoline blending component.Meanwhile,the LPG yield is increased up to 16.58%,in which the content of propylene and iso-butylene is 42.70% and 10.80%,respectively.