This paper discusses the scope and feasibility of an integrated Crude Blending control, optimization and scheduling system to control the qualities of crude feed and end products and automate oil movement and storage operations. Crude blending is different from product blending in concepts, complexity and implementation. Crude is blended upstream of the crude distillation unit whereas product blending is done at downstream side of the unit. This paper identifies six control application modules for an overall integration system to provide the quality control and optimization of crude feed to and products from the crude unit and then discusses briefly the functionality of each control module including samples of user interfaces and information flow.
The feasibility of crude blending control in an existing refinery requires accurate data analysis of its operational practices, crude schedules and sources, physical constraint of tanks and pipelines, etc., to estimate any benefits. This paper also discusses some aspects of methodologies for the data analysis of crude storage and movement operations for conducting a scoping study of crude blending control and optimization system in a refinery.
Here are the generic functions of all essential modules for an integrated system
A typical refinery or any processing plant has two main functions, namely, on-site and offsite operations. The on-site operations focus on the physical separation and chemical reductions of feed-stock into intermediate and final products by processing units. The off site operations involve the movement and storage of raw materials, intermediate and finished products from tanks to processing units and vice versa. Any control automation of processing units provides consistent product quality, better conversion yields, stable and safe operations and result in big tangible and intangible benefits such as overall plant efficiency, better usage of planning and scheduling
and management information systems, etc.
This paper discusses the areas related to material movement in a refinery and presents the functional modules and an overall system for the automation of movement and storage activities in a refinery. The paper also presents how an OM&S system can be integrated effectively with blend control and refinery information system.
The off-site operations in a typical refinery involve the movement and storage of raw materials, intermediate and finished products from tanks to processing units and vice versa. This operation is often termed as Oil Movement and Storage (OM&S). Any control automation of processing units provides consistent product quality, better conversion yields, stable and safe operations and results in big tangible and intangible benefits such as overall plant efficiency, better usage of planning and scheduling and management information systems, etc. However, the implementation of an automation system for the Oil Movement & storage system requires to carry out an accurate cost and benefits analysis for its economic justifications as there are both tangible and intangible benefits and they must be explored thoroughly. This paper discusses methodology to analyze the OM&S operational data and calculate tangible benefits related to automation of material movement in a refinery.
The paper discusses briefly an over-all strategy for the implementation of OM&S automation systems and highlights its salient features.
This paper presents the configurations and architecture of ABB’s state-of-the-art Integrated Blend control, optimization and planning system implemented at two PEMEX refineries in Cadereyta and Tula in Mexico. The blending control system implemented at PEMEX refineries is very sophisticated both in field equipment and control software system. The blending system involves on-line analyzers (NIR) for both stocks and product and the control software system is a full integration of all three levels of control, namely, regulatory blend control, advanced on-line control and optimization and off-line optimization and planning systems. The regulatory blend control (RBC) is implemented in Fisher DCS ProVox and other blend control higher levels, advanced on-line control, optimization and planning, on HP 9000/715 work-stations.
A typical refinery or chemical processing plant has many activities which can be categorized into a number of areas such as feed and products preparations, material movement, stabilization and optimization of unit operations and information management. All refinery activities are further classified as either on-site or off-site operations. Most of the automation projects are focused only towards on-site operations and neglect off-site operations such as oil movement and product blending. However, lately the viability of a plant depends on how strongly the plant management is committed to auto mate these off-site operation areas to maintain its position in today’s very competitive business. This paper discusses three of the major integrated off-site automation systems, namely, crude blending, product blending and oil movement and storage, for typical refinery activities and represents most of the benefits realized from automation. A refinery can save US$ 10-14 million/yr in realized benefits by implementing these off-site integrated systems.
These systems are discussed in this paper only from the point of a concept of view, their details are discussed elsewhere by the author.
