炼油厂氢气网络集成优化研究

通过构建供氢装置、耗氢装置、氢回收装置等通用基础模型,结合炼油厂氢气系统现状,开发了氢气系统模拟数学模型及优化数学模型,并以提高氢气系统安全稳定性为目标,设计了4项优化研究方案。经测算,在满足当前氢气系统用氢需求前提下,制氢装置运行负荷优化方案实施后能减少外购氢10 493 m3/h,年节省成本1 188.58万元;H2梯级利用优化方案实施后减少外购氢420 m3/h,年节省成本387.58万元;H2-轻烃综合回收优化方案实施后减少外购氢12 014 m3/h,年经济效益为9 738.21万元;集成优化方案实施后,炼油厂无需外购氢,仅需1号制氢装置满负荷运行、2号制氢装置负荷提高至87.05%即能满足系统用氢需求。

基于PSA法在炼油厂装置尾气中回收应用研究

在炼油厂的炼油与石化装置的生产过程中,容易产生很多富氢尾气。对尾气中氢气的回收,是全球石油化工相关科技人员的研究执点。当前对炼油厂与石化装置尾气中氢气的回收,主要采用PSA(变压吸附)法、膜分离法与深冷分离等方法,其中以PAS法更具优势与特点。以中国石化海南炼油化工有限公司(海南炼化厂)工业尾气综合利用技术研究项目为例,首先对变压吸附技术应用回收氢气的可行性进行分析;然后对回收流程与装置标定进行详细论述。最后得出结论:使用变压吸附技术能够提升氢气的利用率,回收率达到94.7%,且没有污染,同时PSA装置运行较好,产品能够满足对下游装置氢气的需求。

Modeling and Multi-objective Optimization of Refinery Hydrogen Network

The demand of hydrogen in oil refinery is increasing as market forces and environmental legislation, so hydrogen network management is becoming increasingly important in refineries. Most studies focused on single-objective optimization problem for the hydrogen network, but few account for the multi-objective optimization problem. This paper presents a novel approach for modeling and multi-objective optimization for hydrogen network in refineries. An improved multi-objective optimization model is proposed based on the concept of superstructure. The optimization includes minimization of operating cost and minimization of investment cost of equipment. The proposed methodology for the multi-objective optimization of hydrogen network takes into account flow rate constraints, pressure constraints, purity constraints, impurity constraints, payback period, etc. The method considers all the feasible connections and subjects this to mixed-integer nonlinear programming （MINLP）. A deterministic optimization method is applied to solve this multi-objective optimization problem. Finally, a real case study is intro-duced to illustrate the applicability of the approach.

Integration strategies of hydrogen network in a refinery based on operational optimization of hydrotreating units

Inferior crude oil and fuel oil upgrading lead to escalating increase of hydrogen consumption in refineries.It is imperative to reduce the hydrogen consumption for energy-saving operations of refineries.An integration strategy of hydrogen network and an operational optimization model of hydrotreating(HDT)units are proposed based on the characteristics of reaction kinetics of HDT units.By solving the proposed model,the operating conditions of HDT units are optimized,and the parameters of hydrogen sinks are determined by coupling hydrodesulfurization(HDS),hydrodenitrification(HDN)and aromatic hydrogenation(HDA)kinetics.An example case of a refinery with annual processing capacity of eight million tons is adopted to demonstrate the feasibility of the proposed optimization strategies and the model.Results show that HDS,HDN and HDA reactions are the major source of hydrogen consumption in the refinery.The total hydrogen consumption can be reduced by 18.9%by applying conventional hydrogen network optimization model.When the hydrogen network is optimized after the operational optimization of HDT units is performed,the hydrogen consumption is reduced by28.2%.When the benefit of the fuel gas recovery is further considered,the total annual cost of hydrogen network can be reduced by 3.21×10~7CNY·a^(-1),decreased by 11.9%.Therefore,the operational optimization of the HDT units in refineries should be imposed to determine the parameters of hydrogen sinks base on the characteristics of reaction kinetics of the hydrogenation processes before the optimization of the hydrogen network is performed through the source-sink matching methods.

Improving Refinery Profits via Fine Management of Hydrogen Networks

Hydrogen network management is important to refineries. Various systematic management techniques have been developed to improve the efficiency of refinery hydrogen networks. However, existing methods all treat the hydrogen network separately. The tradeoff between hydrogen network cost and oil processing network benefit has not been explored in the hydrogen network management yet. A novel sensitivity analysis scheme is presented to take oil processing network into consideration. Oil processing unit which is sensitive to both oil processing networks and hydrogen networks is identified first. Then, sensitivity analysis of the unit around the operating point of oil processing networks and hydrogen networks is carried out. Finally, the overall optimal operating condition is obtained. An example of a real Chinese refinery demonstrates the effectiveness of the proposed analysis method.