基于烃类组成的催化裂解反应规律

Deep catalytic cracking reaction rules based on hydrocarbon composition

关键词:  重油  催化裂解  烃类组成  烯烃  芳烃  油产化 

Key words:  heavy oil  deep catalytic cracking  hydrocarbon composition  olefins  aromatics  oil to chemicals

摘要:

目的 研究催化裂解过程中不同烃类的反应规律,提升原料油烃类利用率和目标产物的选择性,挖掘“油产化”的潜力。方法 基于原料油和产物的烃类组成,详细分析了从原料油到反应产物不同烃类的表观转化率,并对不同烃类的转化与生成途径进行了分析与探讨。结果 在催化裂解反应过程中,链烷烃、环烷烃和芳烃的表观转化率分别为93.06%、97.05%和58.53%,其中,单环、双环、三环、四环和五环及以上芳烃的表观转化率分别为61.49%、11.34%、65.17%、29.27%和96.35%。催化裂解产物与原料油物质的量之比为7.68,产物芳烃与原料油芳烃物质的量之比为2.99。液体产物中可进一步转化为目标产物的烃类质量分数为27.50%,产物中单环芳烃通过原料油中非芳烃芳构化反应生成的比例为96.16%。结论 链烷烃和环烷烃催化裂解转化较为彻底,而芳烃表观转化率较低,且不同环数芳烃的表观转化率差异较大,并呈现出奇环数芳烃表观转化率高、偶环数芳烃表观转化率低的特征。裂解反应和芳构化反应是催化裂解过程中最重要的两类反应,不同烃类的表观轻质化顺序为链烷烃>单环芳烃>环烷烃>双环芳烃>三环及以上芳烃,产物中单环芳烃主要来自原料油中非芳烃的芳构化反应,液体产物中可转化为目标产物的烃类仍有进一步压减的空间。 

Abstract:

Objective The reaction rules of different hydrocarbon in deep catalytic cracking (DCC) process was studied to improve hydrocarbon utilization rate and selectivity of target products, and explore the potential of “oil to chemicals”. Methods Based on the hydrocarbon compositions of raw oil and products in DCC, the apparent conversion rate of different hydrocarbons from raw oil to products were analyzed in detail, and the conversion and formation pathways of different hydrocarbons were analyzed and discussed. Results During the catalytic cracking reaction, the apparent conversion rates of paraffin hydrocarbons, cycle-hydrocarbons and aromatics were 93.06%, 97.05% and 58.53%, respectively. In the aromatics, the apparent conversion rates of single ring, double ring, third ring, four ring and five rings and above were 61.49%, 11.34%, 65.17%, 29.27% and 96.35%, respectively. The molar ratio of catalytic cracking products to raw oil was 7.68, and the molar ratio of product aromatics to raw oil aromatics was 2.99. Hydrocarbons with mass fraction of 27.50% in the liquid product could be further converted into the target product, and the proportion of monocyclic aromatic hydrocarbons in the product generated by aromatization reaction from the non-aromatics in the feed oil was 96.16%. Conclusion sThe catalytic cracking conversions of alkanes and cycloalkanes were relatively complete, while the apparent conversion rate of aromatics was relatively low, and the apparent conversions of aromatics with different ring numbers were quite different, showing the characteristics of high apparent conversion rate of aromatic hydrocarbons with odd ring numbers and low apparent conversion rate of aromatic hydrocarbons with even ring numbers. The catalytic cracking reaction and aromatization reaction were the most important reactions of the DCC process. The apparent lightening order of different hydrocarbons was alkanes > monocyclic aromatic hydrocarbons > cycloalkanes > bicyclic aromatic hydrocarbons > tricyclic and above aromatic hydrocarbons. The monocyclic aromatic hydrocarbons in the products mainly came from the aromatization reaction of non-aromatic hydrocarbons in the raw oil. Hydrocarbons that can be converted into target products in liquid products could be further reduced.