Research Of The Energy Systems Optimization Technology On Continuous Catalytic Reforming Unit

Continuous catalytic reforming (CCR) is one of the most important secondary processesin petroleum-refining industries, mainly producing high octane gasoline and aromatics, andproducing hydrogen as byproduct. The energy consumption of CCR is obvious in a refinery,so optimization of CCR unit energy system is of great imprtance to realize the energyconservation and to improve economic benefits for the petrochemical enterprises.Energy system optimization is a technology of energy conservation that is welldeveloped in recent years, and it has a spectacular future. The process simulation andoptimization technology as an important part of energy system optimization technology, isbecoming more and more important and popular in petrochemical enterprises. This thesistakes the600kt·a-1CCR unit as the research background, and the reforming process isanalyzed and optimized to realize the energy conservation. In this thesis, the maincontributions are as follows.1) The energy consumption of CCR unit is analyzed by advanced energy analyzingmethods. The composition of the energy consumption is analyzed, and three-link energymethod is used to find the the potential energy conserving points. Heat exchanger net isanalyzed by pinch technology, to find the unreasonable heat exchanger setpoint. Based on theanalysis, some measures for the energy conversation are given.2) According to the analysis of the whole process of CCR, the whole process model isestablished, including pretreatment system, reforming reactors and product separators, byusing the simulation software of PetroSIM. Fair agreement between the calculated andoperating data is obtained, which proves the madel is effective and convenient for theoperation optimization.3) Based on COM technology, the interface toolbox for Matlab and PetroSIM, MPe Toolbox, is developed. The MPe toolbox enables to drive a PetroSIM simulatin in Matlabenvironment, intergrating the computation capability of Matlab and simulation capability ofPetroSIM. The basic functions and advanced applications of MPe interface toolbox is clarifiedby using the simulation of LPG Recovery process as a instance. And based on MPe Toolbox,the optimizer for CCR unit with genetic algorithms, Ref-OPT, is developed.4) Optimization for the whole process is carried out. For the pre-fractionating column,depentanizer, dehexanizer、C4/C5seperating column, properly lower pressure and lowerreflux can realize energy conversation. The effect rule of main product targets and energyconsumption by key operation conditions such as reactor temperature, reactor pressure,H2/HC, and LHSV, is researched. The multi-objective optimization of CCR unit is built, withreactor temperature, reactor pressure, H2/Oil as operation variables, and aromatic yield,heavy-aromatic yield, energy consumption as multi-targets. And this problem of geneticalgorithms with constrains is solved by using punishment function. The optimum reactor inlettemperature, pressure, H2/Oil are493.1℃,290.05kPa,2.207mol·mol-1.