Hydrocracking is a crucial technology in the refining and petrochemical sectors. It is of great theoretical and practical significance to deeply understand the mechanism of hydrocracking reactions with the aid of reaction kinetics modeling. This paper recounted the research progress in the kinetic modeling of heavy oil distillation and hydrotreating and shows the methods for computing model parameters corresponding to the modeling method and predicting products. The study showed that the reaction kinetics modeling evolved from the decentralized lumped model based on the distillation range from a macroscopic perspective to a continuous lumped model based on production scenarios and then to a complicated microscopic lumped model at the molecular level. In addition, the study compared the advantages and disadvantages of various models in terms of their capacity to reliably predict the composition of products, the intricacy of parameter estimation, rate coefficients, feed dependence, and experimental data required. It also explained the industrial applicability of the lumped model as well as the construction and method for solving molecular hierarchical reaction networks in molecular lumps. Finally, it gives the development prospects of the lumped kinetic model according to the modeling difficulties, the computing power of computers, and the analysis of technology development trends.

The concentration of heavy metal Pb²⁺ is one of the important monitoring indicators in environmental management and control,and excessive Pb²⁺ in the environment will pose a severe threat both to human health and ecological stability.Herein,a polydopamine coating was successfully modified on the electrode surface by a simple in?situ electro?induced polymerization method,and the electrode was further applied to the electrochemical analysis for the detection of trace Pb²⁺ in water.The results show that Pb²⁺ are easily enriched on the electrode surface through chelation with abundant functional groups (-OH,-NH₂,etc.) in the polydopamine surface,and they are redissolved into the aqueous solution from the electrode surface by an anodic stripping voltammetry method.As a result,sensitive and specific electrochemical signals are developed.After analyzing the influences of experimental parameters such as electrolyte,pH value,and enrichment time on the intensity of the electrochemical signals,the study optimized the performance of the proposed method in detecting Pb²⁺ in water,with a detection limit of 32 nmol/L within a detection range of 50~800 nmol/L.Furthermore,the method was applied to detect the Pb²⁺ in actual water samples,with an average recovery rate of about 95%.This simple electrode modification strategy can provide new ideas for designing portable sensitivity sensors to detect and analyze trace heavy metal ions in the environment.