Trade‐off between energy consumption and ethylene recovery rate for quasi‐plant wide operation optimization of the ethylene column with bottom circulatory system in ethylene complex

Abstract

Reducing energy consumption and increasing ethylene recovery rate can effectively optimize the operation of ethylene columns. This paper discusses the trade-off between energy consumption and recovery rate in different scenes. For normal condition, the influences of energy consumption and recovery rate on economic benefits are represented as energy consumption of separation and energy consumption of circulation, while the unseparated ethylene is recycled by the bottom circulatory system. The operation optimization, whose objective is economic benefits, is achieved at the lowest total energy consumption, the sum of energy consumption of separation and circulation. For abnormal condition caused by furnace decoking, the objectives of operation optimization are economic benefits and operability. Operability, affected with remarkable production fluctuation, is quantified by variation of gas and liquid loads. Moreover, the Pareto curve of the multiobjective optimization problem was obtained with total energy consumption and variation of gas/liquid loads as objectives, and the inflection point achieves the equilibrium of economic benefits and operability. Therefore, the balance of recovery rate and energy consumption is crucial to improve economic benefits. Furthermore, moderately operating recovery rate and energy consumption is suitable to maximize economic benefits and operability simultaneously for production fluctuation.

A novel approach to promptly control product quality in precise distillation columns based on pressure dynamic modeling

“…In general, the internal regulating is caused by operation optimization. The operation optimization of the ethylene column has been discussed by the authors . The target of internal regulating is achieving the transition between current and optimized working conditions.…”

“…The majority of dynamic models give a detailed discussion of trays mechanism . The authors study the dynamic of downcomer in the previous work, which improves the liquid dynamic behavior of the column. This paper integrates the vapor dynamic model into the previous model.…”

“…Some relevant studies of the authors were discussed before the pressure dynamic model is proposed. Due to limited length, detailed description of the ethylene column model is seen in Appendix .…”

Thermal Cracking of Hydrocarbons for the Production of Light Olefins; A Review on Optimal Process Design, Operation, and Control

“…Some researchers focused on the ethylene separation column aiming at minimizing construction and operation costs and energy consumption, and increasing recovery rate. Huang et al 116 discussed the trade-off between energy consumption and recovery rate in an ethylene separation column in normal and abnormal (caused by furnace decoking) conditions aiming at maximizing economic benefits and operability. Huang and Luo 113 represented the dynamic optimization of the transition process of a throughput fluctuating ethylene distillation column as a MINLP problem.…”

Process Transition Based on Dynamic Optimization with the Case of a Throughput-Fluctuating Ethylene Column

“…As for practicality, the optimizing strategy is verified via the case study of a commercial ethylene column with fluctuating throughput. The ethylene column discussed in this paper is the extension of previous work by the authors. − …”