Modeling And Optimization Of Scheduling For Ethylene Cracking Furnace System

Ethylene production typically uses crackers of many types and feedstocks to convert various hydrocarbon feedstocks into products such as ethylene and propylene.Each cracker operates with coking,which can lead to lower yields for products such as ethylene propylene,so the cracker needs to be shut down periodically for coking removal operations,and each stoppage of coking removal can affect product yields and production.The ethylene cracking furnace cluster system is an important part of the refinery,producing products such as ethylene propylene that are transported downstream to produce derivatives,so the scheduling of the cracking furnace cluster is modeled and optimized to maximize profits.In addition,today's global awareness of environmental protection is increasingly strong,and the domestic industry is also emphasizing the pollution and carbon emissions,the ethylene industry is a process of high energy consumption and high carbon emissions,in order to maximize profits while taking into account environmental benefits,the adoption of new models and methods to achieve energy saving and emission reduction.This paper first addresses the problem of considering downstream disturbances by adding new constraints to the conventional scheduling model,which ensures that the efficiency of the cluster system is within a certain range of ethylene and propylene yields during the operating cycle by specifying upper and lower limits on ethylene and propylene yields for several critical dates,thus reducing disturbances to downstream processes.In order to reduce the impact on the environment and the human body,it is considered to reduce the emission of pollutants by adding a time window constraint to achieve energy saving and emission reduction.Finally,the integration of the scheduling model for the above two conditions is carried out,and a new mixed-integer nonlinear planning(MINLP)scheduling model that takes into account both downstream upset constraints and emission constraints is proposed,which is transformed into a mixed-integer linear planning(MILP)scheduling model by a new linearization method,achieving the result of maximizing the daily profit with both downstream disturbance and environmental benefits.