摘要
Abstract
[Objective]Under the policy of"Carbon Neutral"and"Carbon Peak",energy saving and consumption reduction in the petrochemical industry are eternal themes.After overall process energy optimization and efficiency improvement,improving the weakest point in energy utilization emerges as a potential strategy.This approach represents an optimal path towards reducing energy consumption and cutting cost in the chemical industry.It is expected that process operation optimization will be realized based on models if the entire process can be accurately simulated.However,the optimization of the entire process,as well as the simulation and optimization of the complete p-xylene production process,have not been achieved.In order to propose a strategy for enhancement from the perspectives of global energy optimization and CO2 emission reduction,and with the aim of achieving the goal of energy reducing and usage reduction,this study developed a steady-state process model for the entire process of the p-xylene aromatics co-production plant using Aspen Plus process simulation software.[Methods]In this research,Aspen Plus process simulation software was used to construct a steady-state process model for the entire process of a p-xylene aromatics co-production plant.To establish the basis for the optimization of aromatics production operations,two functional areas were initially created.Subsequently,the impact of key operating parameters,such as solvent ratio and separation tower reflux ratio,on product quality and unit energy usage was investigated.To fulfill the objective of energy savings and consumption reduction,the energy consumption and fuel gas emission of the entire process model were calculated,and optimization strategies were proposed from the perspective of energy optimization and CO2 emission reduction.[Results]The simulation results of the built model are highly consistent with the original process flow,rendering them suitable for subsequent processes.Following optimization,the top pressure of the reforming stabilizer is set at 1.7 MPa,the feed solvent ratio of the extraction distillation tower is 2.8,and the reflux ratios of the benzene tower,toluene tower,raffinate tower,and finished product tower are 2.0,2.9,1.0,and 1.1,respectively.Using Aspen Energy Analyzer,the process was then energy balanced,and the potential for energy savings was calculated to be 10.33％,with a possible yearly decrease in energy costs of up to 39.5 million CNY.The entire process was estimated to generate 1.18 million tons of fuel gas per year,and when used as a raw material for producing chemical products rather than as fuel,this could result in a reduction of 5.72 million tons of CO2 emissions annually.[Conclusion]The entire process of p-xylene production in aromatics cogeneration plant is simulated using Aspen Plus process simulation software.The whole production process is simplified from the original six units into two parts,C8 enrichment and C8 separation for modeling,offering a more intuitive understanding of the characteristics of p-xylene production process.The steady-state model is used to adjust the operation state of the process and determine the weak link of the process.Through sensitivity analysis,the operating parameters of each tower are optimized while ensuring the satisfaction of the main control indexes.The optimization potential of the whole process is estimated to be 10.33％.Through process optimization,the energy consumption cost of the enterprise can be reduced by 39.5 million CNY per year.It is calculated that the fuel gas generated in the whole process is 1.18 million tons annually.If the fuel gas is transported to the ethylene plant through the pipeline corridor for use as a chemical raw material instead of fuel,the CO2 emission of the enterprise can be reduced by 5.72 million tons per year.It can be seen that the integration of chemical park resources can contribute to achieving carbon neutrality in chemical production.关键词
对二甲苯/流程模拟/工艺优化/节能降耗Key words
p-xylene/process simulation/process optimization/energy saving分类
化学化工
