Effect of Lump Partitioning on the Accuracy of a Commercial Vacuum Gas Oil Hydrocracking Model

Abstract

In an industrial hydrocracking plant, except to the reactor, the separation section can affect the accuracy of the developed mathematical model. In this study, two combined-bed six and seven-lump kinetic models for the hydrocracking of vacuum gas oil in a real refinery are developed and their accuracies for the prediction of product yields are compared. In the six-lump model, the engaged components are selected according to the actual products of the plant, but the seven-lump one is included of lumps which are partitioned based on the specified initial and final boiling points.For both approaches, a complete kinetic network with the catalyst-decay functions is considered. It is found that over a 17-month period of operation from the start of run, the average absolute deviation (AAD%) of the six-lump and the seven-lump models for the yield prediction are 20.51% and 5.21%, respectively for all products. Additionally, the sum of residuals for the seven-lump model has been appreciably decreased in comparison to the six-lump one. Therefore, it is confirmed that partitioning of the products to the lumps with specific boiling points can acceptably decrease the deviation of the prediction. So it is conclusive that including the operation of the separation section in commercial models can effectively increase the accuracy of the model and smooth the prediction error.

A six-lump kinetic model for HDPE/VGO blend hydrocracking

“…One should note that the hydrocracking of the different lumps has been described by means of first-order irreversible reactions with the exception to those reactions in which the HCO lump has acted as a reactant, which have been assumed as second-order irreversible reactions. This strategy is commonly used in the literature [52][53][54] because it describes more accurately the different reactivity of the wide variety of heavy compounds comprehended within the HCO lump. In addition, all the kinetic equations are independent of both H 2 partial pressure and stoichiometry coefficients due to the great H 2 excess in the reaction medium [55,56].…”

Recent Advances in Heavy Oil Upgrading Using Dispersed Catalysts

“…Different lumps proposed: (A) 3-lump, adapted from ref ; (B) 4-lump, adapted from ref ; (C) 5-lump, adapted from ref ; (D) 6-lump [reprinted with permission from ref ; copyright 2015, Taylor & Francis Ltd., United Kingdom, ]; (E) 7- lump, adapted from ref ; and (F) 8-lump [reprinted with permission from ref , Copyright 2013, John Wiley and Sons, Hoboken, NJ. ]…”

New Energy Distribution Network Scheduling Based on Optimized PSO

“…In order to introduce the energy consumption cost of the control system, it is also necessary to make the startup and shutdown times of each unit tend to the lowest value. Under the constraint of wind turbine reactive power output, each wind turbine operates in the mode of tracking the maximum wind power [3][4][5]. The optimal dispatching in this paper is based on the following settings: when the dispatching controls the wind farm, combined with its own characteristics, it uses real-time wind measurement data and ultra short-term wind power prediction data to judge the output value of the next cycle, so as to control the power of each unit within a certain threshold range.…”