俄罗斯含硫原油常压渣油催化裂化反应性能及硫分布规律的研究

利用小型固定流化床对俄罗斯含硫原油常压渣油的催化裂化反应性能进行了考察,并研究了原料油中硫在催化裂化产品中的分布；结果表明,较高的反应温度和较低的剂油比有利于提高产品的轻油收率,降低焦炭产率；而较高的反应温度和较高的剂油比有利于降低汽油中的硫含量,但会导致柴油中的硫含量迅速增加；催化裂化过程中,原料中约40%以上的硫会转化成为分子量很低的硫化物,其次是柴油和焦炭中,分别占25%和10%左右。

STUDY ON FCC REACTIVITY AND SULFUR DISTRIBUTION OF RUSSIAN SOUR CRUDE ATMOSPHERIC RESIDUUM

The Russian sour crude Atmospheric Residuum (AR) FCC experiments were performed in fixed fluidized bed reactors in order to investigate its catalytic cracking characteristics and the sulfur distribution in products. The results showed that its catalytic cracking characteristics are similar to the normal AR. Reaction temperature had less effect on light oil productivity, while the light oil productivity decreased with increase of catalyst-to-oil ratio. During catalytic cracking, 40% of sulfur content in Russian sour crude AR became smaller sulfur compounds such as H2S, 25% of that distributed in diesel as thiophene and its derivatives, 10% of that distributed in coke, only 4%～6% of sulfur compounds such as sulfide and thiol distributed in gasoline. Sulfide and thiol are easy to be deprived as conversing into lighter sulfur compounds such as H2S. Hence sulfur content in gasoline decreased with increase of reaction temperature and catalyst to oil ratio, while the sulfur content in diesel showed reverse tendency because thiophene and its derivatives hardly decomposed under the cracking conditions. When the yield of light oil reached to 63.38%, sulfur concentration was 1197.82 mg/kg in gasoline and 18700.79 mg/kg in diesel oil at 520 ℃ and catalyst-to-oil ratio of 6. Therefore, it is difficult to get better desulfurization effect through optimizing the cracking conditions. The catalyst with desulfurization activity should be used to make much more sulfur content converse to smaller sulfur compounds such as H2S, and then the cleaner light oil with less sulfur could be produced.