MIP系列技术降低汽油硫含量的先进性及理论分析

硫传递系数以同一汽油干点作为基准可以准确有效地评估不同催化裂化技术对汽油的降硫效果。MIP系列技术与常规FCC技术汽油硫含量对比的研究发现，当汽油干点基准相同时，MIP系列技术的汽油硫传递系数均低于常规FCC技术的汽油硫传递系数。MIP-CGP技术与其它多产丙烯催化裂化技术的汽油硫含量对比研究发现，当汽油干点小于185℃时，MIP-CGP技术的硫传递系数为3.93，小于FDFCC－III技术和ARGG技术；当汽油干点大于190℃时，MIP-CGP技术的硫传递系数为5.60，而DCC技术的硫传递系数为19.10，表明MIP-CGP技术降低汽油硫含量远优于其它多产丙烯的技术。分析了MIP汽油的硫含量降低的原因。

ANALYSIS OF MIP SERIES TECNOLOGY IN REDUCING SULFUR CONTENT OF FCC NAPHTHA

Data of sulfur contents of naphtha from running MIP units were collected and analyzed in this paper. The statistical data showed that sulfur transfer coefficient (STC) based on similar naphtha dry point could accurately and efficiently evaluate the effect of naphtha desulfurization by various catalytic cracking technologies. Based on the similar naphtha dry points, the STC of MIP series processes was in the range of 4.91%～7.30%, which was 30～50% lowered as compared with that of conventional FCC process (with a STC of 10%). When the dry point of naphtha was below 185℃, the STC of MIP-CGP process was 3.93%, while those of FDFCC-III process and ARGG process were 6.27% and 10.6%, respectively. When the dry point of gasoline was above 190℃, the STC of MIP-CGP process was 5.60% while that of DCC process was 19.10%. The reasons of having lower naphtha sulfur content with MIP technology were discussed as well. It could be attributed mainly to the following two aspects: firstly, the strong hydrogen transfer reaction trend in the second reaction zone of MIP process might cause the transformation of sulfides into benzothiophene and H2S left naphtha fraction; secondly, the lower olefin content of MIP naphtha might suppress the formation of sulfides.