浅谈原油在线调合技术

阐述了原油在线调合技术在国内外的现状及发展趋势,并具体介绍了原油在线调合体系中的调合方式、快速评价系统及优化调合系统。     

基于序的原油调合调度问题

原油在线调合调度对于平稳混炼原油性质、保障先进控制的实施和优化炼油计划具有重要的意义。原油调合调度问题由于既包括顺序变量又包括连续变量,不存在明确的问题结构,复杂度高,传统的优化方法效率低,不能满足在线实时的要求。本文针对问题的两层结构提出了基于序的求解方案,利用实际原油性质数据的仿真结果表明,基于序的求解算法可以大幅度提高计算效率。     

汽油在线优化调合系统开发和应用

利用先进的在线优化调合软件和调合规则结合在线近红外分析仪(NIR)分析速度快精度高的特点,开发出汽油在线优化调合系统。利用在线分析仪分析的各组分和调合总管成品的质量指标并依照调合属性预测模型实时计算出各组分的最优配方,按照最优配方控制组分流量,实现汽油质量指标的在线优化调合控制,缩短调合时间,降低成本提高效益。     

汽油调合优化软件的开发

针对国内炼油厂的现状,采用分级优化策略开发了汽油调合优化软件。软件提供调合调度优化、离线配方优化和在线调合优化等三个层次的优化方案,以实现对汽油调合工段的全面优化。描述了各优化模块的功能及它们的应用策略,并详细地给出了各模块的优化数学模型,最后阐述了软件的开发及扩展方向。     

炼油厂储运系统创效措施之原油调合

近年,部分炼油企业已经开始适量采购低价油种,将其与企业主要加工的油种混合进入常减压装置,这样可以明显降低原油采购的成本,从源头上提高企业效益。但是,国内大部分的原油调合是靠操作人员在生产过程中,根据装置运行状况摸索混合比例。伴随着原油调合技术的发展,这个问题已经得到了有效的解决。     

近红外光谱分析技术在原油调合中的应用

介绍了当前应用于原油性质快速测定的近红外光谱分析仪和分析技术,以及该技术在原油调合中的应用,分析了该技术在炼厂应用时应注意的问题,为今后技术改进提供参考.该技术的分析系统由分析仪、原油基础数据库、近红外谱图数据库和分析软件组成.     

中国石化华北管道原油调合优化模型开发与应用

运用线性规划理论,以PIMS软件为依托开发了专门用于管道原油调合优化的XPIMS模型,解决了区域原油多厂多周期共同优化问题。其应用案例表明,该模型不仅可同时为三个月的原油运作提供详细的可执行的安排表,而且可以对不同原油进行价格比选,为原油选购提供决策依据。     

原油调合技术在中化泉州石化上的应用分析

本文对中化泉州石化原油调和优化系统进行介绍,结合公司原油调合系统的运行情况,阐述调合系统可以降低原油采购成本,稳定常减压进料性质,改善常减压装置操作,实现原油调合自动化和信息共享,通过炼油企业的计划、调度、操作执行各层面工作整体管理,提升原油处理水平,达到炼油加工效益最大化的目标。     

考虑碳排放因素的汽油调合在线优化

针对国家“双碳”战略目标要求,以炼化企业汽油调合在线优化为研究对象,分析了国Ⅵ汽油新标准下被控属性更多、更严、调合效率要求更高等特点,以及由此带来的调合组分油调整导致调合成品汽油携带碳排放量的变化情况。考虑到传统的汽油调合在线优化一般只考虑调合成本、质量卡边等目标,首先建立了非线性的汽油调合辛烷值、蒸气压和馏程等软测量模型,然后构建了基于调合效应的汽油调合优化模型,优化目标中引入调合成品油二氧化碳排放最低化目标,开发了一种融合携带碳排放特征的汽油调合优化模型。为满足在线调合优化需求,优化模型中考虑了实际累积调合过程,将调合工艺过程中储罐汽油属性合格转化成调合头属性区间合格,利用调合头处优化的属性补偿已调合体积和罐底油的属性偏差。仿真结果表明,设计的考虑碳排放因素汽油累积调合优化技术能很好地满足汽油调合在线优化需求,为国Ⅵ标准和碳交易背景下汽油调合工艺设计及在线优化控制提供了技术支撑。     

针对原油性质变化的常减压先进控制研究与应用

针对原油性质变化对常减压装置操作造成的巨大困难,提出了一种稳定原油性质和引入原油性质参数到软测量和控制模型的先进控制综合解决方案。一方面,对待混炼的多种原油进行调度和掺炼比优化,使实际进入常减压装置进行炼制的调合原油性质相对稳定,装置操作参数变化较小,减少工作点大幅变化过程中所产生的波动。另一方面,针对仍然存在的原油性质小幅度变化,在软测量和预测控制建模中引入反映原油性质的馏程参数,克服原油性质变化所引起的扰动。现场实际装置的应用结果说明了此综合方案的有效性。     

The optimization and prediction of properties for crude oil blending

Research into the properties of mixed crude oils has been the most important research for refineries and oil transportation. Because the desirable nature of mixed crude oils is a powerful guarantee for normal operations and corporate earnings. In this paper, the optimization and prediction model for Shanbei crude oil blending is established. The objectives were to improve the total yield of fractions and the compatibility and to reduce the viscosity of the mixed crude oils. After solving the model, two applicable proportions for mixed crude oils were given. With these proportions, two samples of mixed oils were prepared and distilled. The test results showed that the model was valid. The study of the viscosity and compatibility index was introduced to the optimization model because forecasting those properties in mixed crude oils has a certain significance.     

E3 Analysis for Crude and Vacuum Distillation System

Crude oil blending is a very common practice in petroleum refineries, where the main focus is to minimize the total purchase cost of crude oils under specified blending oil properties. Crude oil blending actually has significant impacts on energy consumption from heating furnaces during crude oil processing. Conceivably, furnace energy consumption from burning fuels such as natural gas, fuel oil, or propane causes huge amounts of CO₂ emissions. In this paper, a methodology framework for crude oil blending and processing with simultaneous consideration of energy, emission, and economic profit (E3) is developed. It includes four stages of work: steady‐state modeling, heating energy consumption calculation, emission model development, and economic evaluation. With Aspen HYSYS simulation, the developed methodology provides a quantitative support for refinery to identify an optimal E3 operating strategy. A case study is implemented to demonstrate the efficacy of this methodology.     

原油作业过程优化的研究进展

原油作业过程是石油供应链的重要组成环节,包括炼油企业生产过程中的原油采购、原油分配、原油输送、原油储存和原油调和等多个工业流程。原油作业过程优化具有很高的学术理论价值与工业应用价值,与其相关的研究工作是目前学术界与工业界共同关注的热点。首先简要描述了原油作业过程,并对其优化问题的难点进行分析;其次,分别从优化模型、优化算法以及不确定性优化方法三个研究角度,重点阐述了原油采购优化、原油储运优化、原油调和优化以及不确定性条件下原油作业优化四个主要研究方向的学术进展,并对当前已有的研究成果进行了归纳总结;最后,对原油作业过程优化当前存在的一些问题提出了建议,并对该领域未来的发展方向与趋势进行了展望。     

含硫和高硫原油的加工技术

介绍了俄罗斯原油、委内瑞拉原油的一般性质及目前国内首套加工俄罗斯原油的5.5 Mt/a常减压装置的主要工艺路线和新技术特点,并针对俄罗斯原油的性质和该常减压装置的设计特点、运行中存在的问题和采取的对策及建议进行了分析讨论,如装置对加工俄罗斯原油的适应性问题、以及轻烃回收问题等,同时也对3.5 Mt/a常减压装置掺炼委内瑞拉高硫原油以及第二次加工装置的运行情况加以分析,为国内大量加工俄罗斯原油及委内瑞拉原油装置的设计提供了良好的借鉴经验。     

Continuous‐time modeling and global optimization approach for scheduling of crude oil operations

Scheduling of crude oil operations is a critical and complicated component of overall refinery operations, because crude oil costs account for about 80% of the refinery turnover. Moreover, blending with less expensive crudes can significantly increase profit margins. The mathematical modeling of blending different crudes in storage tanks results in many bilinear terms, which transforms the problem into a challenging, nonconvex, and mixed‐integer nonlinear programming (MINLP) optimization model. Two primary contributions have been made. First, the authors developed a novel unit‐specific event‐based continuous‐time MINLP formulation for this problem. Then they incorporated realistic operational features such as single buoy mooring (SBM), multiple jetties, multiparcel vessels, single‐parcel vessels, crude blending, brine settling, crude segregation, and multiple tanks feeding one crude distillation unit at one time and vice versa. In addition, 15 important volume‐based or weight‐based crude property indices are also considered. Second, they exploited recent advances in piecewise‐linear underestimation of bilinear terms within a branch‐and‐bound algorithm to globally optimize the MINLP problem. It is shown that the continuous‐time model results in substantially fewer bilinear terms. Several examples taken from the work of Li et al. are used to illustrate that (1) better solutions are obtained and (2) ε‐global optimality can be attained using the proposed branch‐and‐bound global optimization algorithm with piecewise‐linear underestimations of the bilinear terms. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Simultaneous optimization of heat-integrated crude oil distillation systems☆

Crude oil distil ation is important in refining industry. Operating variables of distil ation process have a critical ef-fect on product output value and energy consumption. However, the objectives of minimum energy consumption and maximum product output value do not coordinate with each other and do not lead to the maximum eco-nomic benefit of a refinery. In this paper, a systematic optimization approach is proposed for the maximum an-nual economic benefit of an existing crude oil distil ation system, considering product output value and energy consumption simultaneously. A shortcut model in Aspen Plus is used to describe the crude oil distillation and the pinch analysis is adopted to identify the target of energy recovery. The optimization is a nonlinear program-ming problem and solved by stochastic algorithm of particle warm optimization.     

New approach for scheduling crude oil operations

Scheduling of crude oil operations is crucial to petroleum refining, which includes determining the times and sequences of crude oil unloading, blending, and CDU feeding. In the last decades, many approaches have been proposed for solving this problem, but they either suffered from composition discrepancy [Lee et al. 1996. Mixed-integer linear programming model for refinery short-term scheduling of crude oil unloading with inventory management. Industrial and Engineering Chemistry Research 35, 1630-1641; Jia et al., 2003. Refinery short-term scheduling using continuous time formulation: crude-oil operations. Industrial and Engineering Chemistry Research 42, 3085-3097; Jia and Ierapetritou, 2004. Efficient short-term scheduling of refinery operations based on a continuous time formulation. Computer and Chemical Engineering 28, 1001-1019] or led to infeasible solutions for some cases [Reddy et al., 2004a. Novel solution approach for optimizing crude oil operations. A.I.Ch.E. Journal 50(6), 1177-1197; 2004b. A new continuous-time formulation for scheduling crude oil operations. Chemical Engineering Science 59, 1325-1341]. In this paper, coastal and marine-access refineries with simplified workflow are considered. Unlike existing approaches, the new approach can avoid composition discrepancy without using iterative algorithm and find better solution effectively. In this approach, a new mixed integer non-linear programming (MINLP) formulation is set up for crude oil scheduling firstly, and then some heuristic rules collected from expert experience are proposed to linearize bilinear terms and prefix some binary variables in the MINLP model. Thus, crude oil scheduling can be expressed as a complete mixed integer linear programming (MILP) model with fewer binary variables. To illustrate the advantage of the new approach, four typical examples are solved with three models. The new model is compared with the most effective models (RKS(a) and RKS(b) models) presented by Reddy et al. [2004a. Novel solution approach for optimizing crude oil operations. A.I.Ch.E. Journal 50(6), 1177-1197; 2004b. A new continuous-time formulation for scheduling crude oil operations. Chemical Engineering Science 59, 1325-1341], which proves that the new approach is valid and feasible in most small-size and medium-size problems.