摘要
催化裂解 (DCC)是从催化裂化衍生的生产丙烯的新技术。石蜡基原料的丙烯质量产率可以达到2 3% ,而中间基原料的丙烯产率约为 17%。催化裂解汽油再循环到催化裂解装置可以增产 3.5 %的丙烯 ,但汽油产率有所下降。 75～ 15 0℃催化裂解汽油的 BTX体积含量达到 5 7.6 % ,其中甲苯和二甲苯分别为 2 1.9%和 30 .3%。催化裂解催化剂是一个含改性五元环中孔沸石的固体酸催化剂 ,汽油一次产物在中孔沸石内进行二次裂化转化为轻烯烃。已开发出一系列的催化裂解催化剂以适应不同目的的需要 ,如最大量丙烯生产、最大量异构烯烃生产 ,最大原料掺渣油量等。自 1990年以来国内外共有 7套催化裂解工业装置正在运转 ,其中 3套是由催化裂化装置改造成的 ,而另外 4套包括 TPI公司 75 0 kt/ a工业装置是新建的。目前 TPI公司的催化裂解装置正满负荷运转 ,加工掺 40 %常压渣油原料。尽管现在加工的原料比设计原料重 ,但丙烯产率仍可达到设计值。
DCC is a new technology derived from FCC for propylene production.The propylene yield can reach 23 m% with paraffinic feed and around 17 m% with intermediate base feed.A portion of DCC cracked naphtha recycled in a commercial unit resulted in a propylene yield increment of 3.5 m% at some expense of naphtha.The total BTX in the 75~150℃ naphtha fraction was 57.6 v%,in which toluene and xylenes were 21.9 v%and 30.3 v% respectively. DCC catalyst consists of a modified mesopore zeolite with pentasil structure for primary product of naphtha range to undergo secondary cracking for producing light olefins.A series of DCC catalysts was formulated for various objectives,such as maximun propylene,maximum isoolefins,and metal tolerance for residual oil processing,etc. Seven commercial units have been put into production since 1990 inside and outside of China,in which three of them were revamped from existing FCCUs,and the other four were grassroots units including a 750kt/a unit in TPI Company,Thailand.Currently,the TPI unit is running in full design capacity with about 40 m% of atmospheric residual oil in the feedstock.Although the feedstock is much heavier than design,the propylene yield still keeps around the design value.The commercial experiences of some units are presented.
出处
《当代石油石化》
CAS
2001年第10期31-35,共5页
Petroleum & Petrochemical Today
