Multi-site utility integration—an industrial case study

Mitsubishi Kasei and Mitsubishi Petrochemical merged to become Mitsubishi Chemical in 1994 making it the largest chemical company in Japan. This allows two original companies’ production sites, especially for those are physically built next to each other, to improve themselves by multi-site integration. Mitsubishi Yokkaichi production plant site is one of the typical examples, which consists of three individual plant sites in the old company structure. Each plant site contains a utility plant to generate steam and electricity for chemical production. After the company merge, connecting steam and electricity among plant sites have been carried out for better flexibility, efficiency as well as capability of the utility systems. Besides these, there are still many other improvement alternatives. A site-model, which includes all three utility plants and production units, was then developed to explore further opportunities. In this paper, applications at Mitsubishi Yokkaichi production site are presented to illustrate the features of the site-model.     

Synthesis,optimal planning and scheduling for process plant utility systems

A systematic methodology is presented for the synthesis, optimal planning and scheduling of plant utility systems. The methodology first addresses long-term synthesis and planning problems and continues with short-term maintenance scheduling applications. The synthesis approach determines new units, their layout, their number and capacities, as well as the operating strategies appropriate in view of process variations. The scheduling problem methodology determines maintenance, along with shut-down and start-up schedules for uncertain operational scenarios. The optimisation technology is applied in the form of natural decomposition schemes.     

The integration of production plan and operating schedule in a pharmaceutical pilot plant

In reality, planning and scheduling activities are loosely integrated. In the case of a complex supply chain, it might be too difficult to maintain both long-term and short-term information within one large model. However, in the case of a single facility and relative short time horizon this task becomes feasible. This is the case in a pharmaceutical pilot plant, where a 2- or 3-year planning horizon is the most one would expect due to frequent changes in the products and their demands. In earlier work, we decomposed the pilot plant planning and scheduling problem into long-term planning of resources and short-term scheduling of operations [Computer Aided Process Eng. 8 (2000) 1057]. The long-term plan is mainly concerned with allocation of human resource, such as operators, engineers, chemists, and analysts to projects that have uncertain timelines. The short-term schedule fixes the human resources and considers the scheduling of activities in the pilot plant itself. The algorithm resolves uncertainty in future projects by over-allocating resources so that, on average, resource constraints are met. In this paper, we continue this exploration. In particular, we explore techniques for combining the long- and short-term into one plan without creating undue burden on the solver and the planning group. The uncertainty is a daily life of a pharmaceutical pilot plant. We present a methodology to deal with it without compromising the accuracy of the operating schedule.     

PET装置开停车过程总结

对PET装置开停车过程的工艺操作进行探讨,主要包括目标值跟踪功能控制系统升温,酯化反应器带料开车,开车时进浆料的技术要点,停车时酯化反应的控制,黏度控制和反应釜的煮洗等。对开停车的历史数据进行了对比。     

硫酸工厂氢气闪爆风险评估及探讨

以璐彩特美国德州工厂的氢气闪爆案为例,从理论研究到历史氢爆案例研究,分析了常规硫酸工厂在日常运行和开停车期间存在的氢气闪爆风险,并以璐彩特(中国)工厂为实例进行具体的风险研究,讨论可能的改进行动项,以便对一般硫酸工厂的安全生产提供指导。     

改进PSO算法在蒸汽动力系统多周期运行优化中的应用

为了满足石化企业工艺过程对蒸汽和电力不断变化的要求,实现企业降低成本、节能降耗的目的,必须保证蒸汽动力系统在最优的状态下运行。针对这一问题在以往研究的基础上提出了包括设备维护和启停费用的改进的混合整数线性规划模型,利用改进的PSO算法对其求解,并通过实例证明了利用该模型、使用改进的PSO算法能很快得到最优的方案,并节省了大量的运行成本。     

乙烯装置挖潜改造开停车方案优化与方法

乙烯装置是乙烯联合化工厂挖潜改造关键，开停车是挖潜改造关键环节。文中主要阐述天津联合化学有限公司乙烯装置挖潜改造开停方案优化与方法，为同行业乙烯装置挖潜改造提供借鉴。     

水泥磨前掺加粗矿粉的实践应用

粒化高炉矿渣粉是水泥生产中的重要活性混合材料,矿粉活性的高低直接影响水泥产品质量。生产过程中存在磨机开停或检修后磨合阶段,此阶段所生产的矿粉存在细度偏粗、比表面积低、早期活性偏低等问题。针对此问题,我公司将该部分矿粉通过水泥磨头物料仓微机计量入磨与熟料、石膏和其它辅助混合材共同粉磨,达到稳定水泥质量,实现最终消化的目的。     

尿素装置停车实现"零"排放过程分析

大型尿素装置的生产过程中会产生大量的废水,在正常生产时都较容易回收利用,但在停车过程中将产生大量含氨的废水和废气,因为气相氨较难保存,所以停车时往往会有部分的氨排向空中而造成大气污染和氨的损失.通过对现有装置和停车方法进行改进将气相氨转变为氨水,待再次开车后回收利用,从而使装置停车实现"零"排放.     

典型水煤浆制气装置大检修及开车情况介绍 隋兴彬

中国石化齐鲁分公司煤制气装置在2013年春季进行了首次全面大检修，介绍检修的主要项目．检修过程发现和解决问题对策，通过精心准备操作，实现了“事故为零、排放为零、开车1次成功”的检修目标。     

高压甲铵泵出口缓冲罐制造总结

尿素高压甲铵泵2台出口缓冲罐在发现裂纹后，已不能再继续使用。在大修的较短时间内，新购材料无法保证工期的情况下，利用已有材料，采取设备添加松衬里的办法，重新制作2台新设备。保证了系统按时开车运行。     

改齿式联轴器为膜片联轴器

根据检、维修现场齿式联轴器经常失效的现象，分析齿式联轴器损坏的原因及膜片联轴器的优异性能，改部分齿式联轴器为膜片联轴器，为装置的长周期，大负荷生产创造了有利条件。     

乙烯装置开停车过程节能减排技术进展

随着我国乙烯装置的大型化、原料价格的增长以及环保要求的日益严格,乙烯装置开停车过程的节能减排研究逐渐受到乙烯企业和国内外研究者的重视。综述了国内外关于乙烯装置开停车过程中的节能减排技术,并对动态模拟在开停车节能减排中的应用进展进行了介绍。     

乙烯气往复压缩机组十字头及滑道技术改造

储运厂乙烯气进口往复压缩机组十字头系统采用十字头与滑道相同材质的结构,在使用过程中出现了配合面拉伤、温度升高连锁停机故障,该机组一开一备,为聚丙烯装置输送原料,2台都发生故障时会导致聚丙烯装置停工等重大事故。我们及时对该机组十字头与滑道进行解体改造,改变了十字头系统材质配合状态,经过计算,合理增大了配合间隙,增大了润滑油槽长度及深度,保证修复后开机试运一次成功。     

Decision support framework for coordinated production and transport scheduling in SCM

The efficient coordination of production and distribution systems becomes a challenging problem as companies move towards higher collaborative and competitive environments. Focusing on the operational level of supply chain management (SCM), a framework is proposed to address the interrelated production and transport scheduling problems from the perspective of a production plant of a multi-site system that owns, or leases on a long-term basis, a fleet of vehicles to distribute the products. This framework aims to support the coordination of production and transport activities to properly manage the inventory profiles and material flows between sites. Both production and transport problems are defined as detailed scheduling problems, and different algorithms, either mathematical or heuristic-based, can then be used for their resolution. The flexibility and applicability of the proposed modeling framework is illustrated through two different case studies, which highlight the benefits of coordinating both activities in such a complex supply chain (SC) environment.     

Simultaneous regular and non-regular production scheduling of multipurpose batch plants: A real chemical–pharmaceutical case study

Regular and non-regular production can often be found in multipurpose batch plants, requiring two distinct operating strategies: campaign and short-term production. This paper proposes a solution approach for simultaneous scheduling of campaign and short-term products in multipurpose batch plants. Regular products follow a cyclic schedule and must cover several product deliveries during the scheduling horizon, while non-regular products have a non-cyclic schedule. The proposed approach explores the Resource-Task Network (RTN) discrete-time formulation. Moreover, a rolling horizon approach, and reformulation and branching strategies have been applied to deal with the computational complexity of the scheduling problem. Real case instances of a chemical–pharmaceutical industry are solved, showing the applicability of the solution approach.     

硫酸装置熔盐系统的设计及运行

根据生产实践,论述WSA硫酸装置熔盐系统的设计及在正常操作与开停车期间的控制参数。详细介绍了熔盐性质,提出在熔盐充装、熔盐管道、阀门、泵槽、保温设置等方面应注意的事项和规避的风险,以保证硫酸装置的稳定运行。     

A novel network-based continuous-time representation for process scheduling: Part II. General framework

In the first part of this series of papers we presented a new network-based continuous-time representation for the short-term scheduling of batch processes, which overcomes numerous shortcomings of existing approaches. In this second part, we discuss how this representation can be extended to address aspects such as: (i) preventive maintenance activities on unary resources (e.g., processing and storage units) that were planned ahead of time; (ii) resource-constrained changeover activities on processing and shared storage units; (iii) non-instantaneous resource-constrained material transfer activities; (iv) intermediate deliveries of raw materials and shipments of finished products at predefined times; and (v) scenarios where part of the schedule is fixed because it has been programmed in the previous scheduling horizon. The proposed integrated framework can be used to address a wide variety of process scheduling problems, many of which are intractable with existing tools.     

Integration of a Gas Fired Steam Power Plant with a Total Site Utility Using a New Cogeneration Targeting Procedure

A steam power plant can work as a dual purpose plant for simultaneous production of steam and elec-trical power. In this paper we seek the optimum integration of a steam power plant as a source and a site utility sys-tem as a sink of steam and power. Estimation for the cogeneration potential prior to the design of a central utility system for site utility systems is vital to the targets for site fuel demand as well as heat and power production. In this regard, a new cogeneration targeting procedure is proposed for integration of a steam power plant and a site utility consisting of a process plant. The new methodology seeks the optimal integration based on a new cogenera-tion targeting scheme. In addition, a modified site utility grand composite curve （SUGCC） diagram is proposed and compared to the original SUGCC. A gas fired steam power plant and a process site utility is considered in a case study. The applicability of the developed procedure is tested against other design methods （STAR？ and Thermoflex software） through a case study. The proposed method gives comparable results, and the targeting method is used for optimal integration of steam levels. Identifying optimal conditions of steam levels for integration is important in the design of utility systems, as the selection of steam levels in a steam power plant and site utility for integration greatly influences the potential for cogeneration and energy recovery. The integration of steam levels of the steam power plant and the site utility system in the case study demonstrates the usefulness of the method for reducing the overall energy consumption for the site.     

浅谈化工企业检修作业事故的成因与防范措施

化工企业生产过程高温、高压,使用原料等多具有易燃、易爆、有毒、有害、腐蚀性强等特点,所有这些都给化工企业的检修作业提出了高要求。本文主要针对化工企业在检修作业中发生事故的现状,结合本人所在企业检修作业的特点,有针对性的提出在此类生产型企业中较为有常见的检修事故成因和有效的防范措施,以供借鉴。