乙烯／乙烷精馏-膜耦合分离系统的HAZOP量化分析

Quantitative HAZOP analysis of ethylene/ethane hybrid distillation-membrane separation system

危险与可操作性(HAZOP)分析技术自问世以来,作为定性的风险分析方法广泛应用于各个领域,许多发达国家已经立法强制其在工程建设项目中推广应用。近年来,随着该技术的完善,其量化分析已成为一种趋势。精馏-膜耦合分离作为一种新开发的高效节能分离方法,主要用于分离普通精馏难以分离的重要体系,例如共沸体系、存在浓度夹点的体系、挥发度相近的体系,然而至今没有文献对其危险与可操作性进行分析。针对乙烯/乙烷精馏-膜耦合分离系统,结合课题组基于UniSim Design软件开发的Membrane Extension模块建立耦合系统模拟模型,将HAZOP分析方法与过程模拟相结合对精馏-膜耦合系统进行HAZOP量化分析。选定精馏塔工艺参数进料温度、进料流量、侧线采出量为考察对象,分析不同程度的偏差对系统的影响。基于模拟结果,首先依据耦合系统中各个设备的安全操作范围,对HAZOP分析偏差进行量化分级,得出了参数的安全阈值和偏差等级。其次对该系统进行HAZOP分析结果的量化,依据偏差等级分析不同程度偏差产生的原因、可能导致的后果以及后果的严重程度,并根据事故发生的可能性和严重程度,得到事故的风险等级,最后通过HAZOP分析偏差和分析结果的量化得出乙烯/乙烷精馏-膜耦合分离系统的HAZOP量化分析报告。

The HAZOP analysis technology has been widely used in various fields as a high qualitative risk analysis method since the beginning, and many developed countries have enforced the HAZOP analysis into construction projects by legislation. With the continuous development of the technology, the research of HAZOP tends to be quantitative in recent years. As an energy-efficient separation method newly-developed, hybrid distillation-membrane separation process has been proposed by a number of literatures. Hybrid distillation-membrane separation process was used to separate many industrially important systems. These systems were difficult or impossible to be separated by simple continuous distillation because the phase behavior contains an azeotrope, a tangent pinch, or an overall low relative volatility. But so far HAZOP analysis for the hybrid separation process has rarely been reported. Simulation model of ethylene/ethane hybrid separation system was built using the Membrane Extension module developed based on UniSim Design software by our research group. Quantitative HAZOP analysis of hybrid distillation-membrane separation system was achieved by combining HAZOP with process simulation. Then effects of different grade deviations of parameters, including feed temperature, feed flow rate and side-draw flow rate of the rectifying column, were investigated. On the basis of simulated results, firstly, deviations used in HAZOP analysis were quantified according to the safety operation scopes of the equipments, then safety thresholds were achieved. Secondly, results of HAZOP analysis were quantified. Reasons of the deviations, consequences of the accident and the severity were analyzed according to the deviation levels. Then the hazard levels were developed. Finally, an analysis report of ethylene/ethane hybrid distillation-membrane separation system was provided based on deviations used in HAZOP analysis and results of HAZOP analysis.