重油分级催化裂化反应性能

Catalytic Cracking Performance of Heavy Oil After Fractionation

利用小型固定流化床实验装置,对重油中不同馏程范围馏分裂化性能进行研究,发现重油中存在反应性能差异明显的两类馏分,且在减压渣油中仍含有部分优质馏分,依此采用分级方法将重油分为优质、劣质裂化原料。实验对比了各分级点分级后重油的催化裂化产物分布,也对比了重油分级前后催化裂化反应产物分布的变化。结果表明,适当提高分级点温度,将减压渣油中的一部分馏分切入优质原料,通过分别裂化可以改善重油整体的产物分布,并确定了长庆、济南重油适宜的分级点分别在500～540℃和500～520℃范围。分级后针对不同性质原料匹配各自的反应区间,重油整体的轻质油收率提高,焦炭和干气的收率降低;且随着催化裂化原料掺炼渣油比例的增加,采用重油分级催化裂化提高目的产物的优势越明显。

Two kinds of heavy oils were fractioned into several fractions respectively, and their catalytic cracking reaction performances were investigated in a confined fluidized bed reactor. Based on their different reaction performance, the heavy oil could be classified by being cut at the fractional temperature into high-quality fraction and poor-quality fraction as the feed of catalytic cracking, and there was a small fraction in conventional vacuum residue （VR）, whose reaction performance was close to that of high-quality fraction. Comparison between the cracking product distributions of each fraction obtained by different fractional temperatures was carried out, and comparison between the product distributions of heavy oil before and after being cut was carried out too. The results showed that increasing the fractional cut temperature properly could improve the product distribution of heavy oil because of adding the small part of fraction into high-quality fraction. The reasonable fractional cut temperatures of Changqing and Jinan feedstock were in the range of 500 -- 540~C, and 500-- 520~C, respectively. The product distribution of heavy oil after being cut was improved, resulting in the increase of light oil and the decrease of coke plus dry gas. With the increase of blending ratio of VR in heavy oil, the improvement of the desired products after fractionation was enhanced gradually.