低生焦、高低碳烯烃产率的催化裂化工艺研究

Study on catalytic cracking process with low coke and high light olefins

针对多产低碳烯烃的高反应苛刻度的催化裂化工艺因转化率高导致焦炭产率过高问题,提出优化催化裂化原料性质和原料油分子结构与催化剂孔道构成有效空间约束理念,由此形成了低生焦、高低碳烯烃产率的催化裂化工艺研究思路。试验结果表明:对于不适合作为多产低碳烯烃的加氢重油,采用溶剂脱沥青与催化裂化组合技术脱除加氢重油胶质与沥青质,脱沥青油作为催化裂化原料,焦炭产率大幅度降低;对于饱和烃含量高的大庆蜡油,中孔MFI分子筛孔道(TCC-1催化剂)与大庆蜡油分子的空间约束有效性明显优于大孔Y分子筛(MMC-2催化剂),焦炭产率降低28.9%,烯烃产品产率增加6.3百分点;当采用芳烃含量较高的加氢蜡油时,随着反应物中的多环芳烃含量上升,多环芳烃在中孔MFI分子筛上发生缩合反应也难以得到有效抑制。这些研究结果为深度开发低生焦、低能耗和高烯烃产品的中孔分子筛重油催化裂化技术提供更深入的理论认识,为炼油转型发展技术开发提供更加可靠的理论依据。

In order to solve the problem of high coke yield caused by high conversion rate in catalytic cracking process with high reaction harshness for high yield of light olefins, the concept of optimizing the properties of catalytic cracking feedstock to form an effective spatial constraint between the feedstock molecular structure and the pore structure of catalyst is proposed. Thus, a research idea of catalytic cracking process with low coke and high light olefins yield is formed. The test results show that for the hydrogenated heavy oil that is not suitable for the production of light olefins, the integration technology of solvent deasphalting and catalytic cracking is used to remove the resin and asphaltene of hydrogenated heavy oil, and the deasphalted oil is used as the feedstock of catalytic cracking, and the coke yield is greatly reduced. For Daqing VGO with high saturated hydrocarbon content, the spatial constraint effectiveness of mesoporous MFI molecular sieve(TCC-1 catalyst) with Daqing VGO molecules is significantly better than that of macroporous Y molecular sieve(MMC-2 catalyst). The coke yield decreases by 28.9% and the olefin yield increases by 6.3 percentage points. When HVGO with higher aromatic content is used, the condensation reaction of polycyclic aromatics on mesoporous MFI molecular sieve is difficult to be effectively inhibited with the increase of polycyclic aromatics in the reactants. These research results provide a more in-depth theoretical understanding for the deep development of mesoporous molecular sieve heavy oil catalytic cracking technology with low coking, low energy consumption and high olefin products, and provide a more reliable theoretical basis for the transformation and development of oil refining technology.