催化裂化过程烃类分子水平转化规律分析

系统分析了某催化裂化装置从原料油到反应产物的烃类分子水平转化规律，给出了不同烃类的表观转化率和芳烃生成与转化的结果。结果表明：催化裂化反应前后，链状烃质量分数增加31.47百分点、环烷烃分数组成降低23.21百分点、芳烃质量分数减少17.47百分点，产物与原料油的烃类物质的量之比为5.92。催化裂化表观转化率为80.77%，其中链状烃、环烷烃和芳烃的表观转化率分别为91.99%，96.62%，66.10%；在环烷烃中单环、双环和三环及三环以上环烷烃的表观转化率分别为94.60%，97.17%，97.72%；芳烃中单环、双环和三环及三环以上芳烃的表观转化率分别为86.60%,19.64%,68.56%。产物中单环、双环和三环及三环以上芳烃来自原料油同环芳烃的烷基裂化或脱烷基反应的比例分别为13.4%,38.8%,86.1%，其余部分来自原料油或中间产物的芳构化或稠环化反应。

MOLECULAR-BASED HYDROCARBON CONVERSION RULES IN FCC PROCESS

The conversion laws from feedstock to product on molecular level were studied based on the operation data from a commercial FCC unit, and the results of the apparent conversion of different hydrocarbons with aromatics formation and conversion were given. The results showed that comparing the compositions between feedstock and product, the paraffin hydrocarbon was increased by 31.47 percentage points, the naphthenic hydrocarbon was decreased by 23.21 percentage points, and the aromatic hydrocarbon was decreased by 17.47 percentage points. The mole ratio of product to feedstock was 5.92. The general apparent conversion was 80.77%, and the apparent conversions of paraffin, naphthenic and aromatic hydrocarbons were 91.99%, 96.62% and 66.10%, respectively. In cycloalkanes, the apparent conversions of monocyclic, dicyclic and tricyclic plus naphthenic hydrocarbons were 94.60%, 97.17% and 97.72%, respectively. In aromatics, the apparent conversions of monocyclic, dicyclic and tricyclic plus aromatic hydrocarbons were 86.60%, 19.64% and 68.56%, respectively. The proportions of monocyclic, dicyclic and tricyclic plus aromatic hydrocarbons in products by cracking the aromatic hydrocarbons with the corresponding aromatic ring number in feedstock were 13.4%, 38.8% and 86.1%, respectively, and the rests came from the aromatization or thickening of the feedstock or intermediate products.