On-line Refinery Optimization
Optimizing integration of planning and plant control is one of the challenges for oil refiners today. Refiners maximize their margins by running a planning LP optimization weekly or monthly to find the most profitable crude blends, operating rates and constraints on which to operate. The scheduler then breaks the plan into a daily, feasible, schedule of production for all units. These LP and scheduled targets are passed on to the Unit MVCCs to implement. However, the LP solves for the optimum of average operation over the planning period; the production targets are a daily feasible, but not necessarily optimal schedule; and the MVCC optimum is generally limited by linearity.
The [RMO]™ Solution
The non-linear, chemical engineering model of [RMO]™ provides more accurate and more valuable solutions than the off-line regression models in planning and scheduling tools as well as a significant addition to the integrating functionality of [RPM]™. [RMO]™ optimizes the scheduler's feasible solution for product and intermediate stream cutpoints and reactor severities by profit optimization of the scheduler's daily targets using a simplified chemical engineering model of feedstock distillation and reaction kinetics. When [RMO]™ is operated in closed-loop mode it automatically closes the GAP on all product pools and, when opportunity presents itself, will seek to exceed the Planned/Scheduled profit(subject to scheduler's and operators constraints). As with [RPM]™ the source of product pricing is user configurable so this optimization can use more current product pricing than was used in the LP plan, if the user chooses to. Automation of the integrating work processes to integrate planning, scheduling and operations is also enhanced.
[RMO]™ adds functionality to the business process supported by [RPM]™ and works with our clients' existing planning, scheduling and control and optimization applications to capture on-line, opportunities that are not addressed by the planning and scheduling model. It acts as a real-time, optimizing integrator between planning and scheduling output and controls. [RMO]™ calculates its current contribution to refinery profit in real-time. When the refinery manager asks how much the application is contributing to the refinery bottom line, a reliable, quantitative and unequivocal answer is always available.
Developed by two of the pioneers of refinery Unit RTO, Ron McLeod and Steve Treiber, Refinery Multi-unit Optimization [RMO]™ is a new approach to refinery on-line optimization that dramatically reduces the complexity of RTO while capturing new benefits of inter-unit optimization as well as traditional unit optimization benefits. [RMO]™ uses a chemical engineering model based on material balance and kinetic equations to optimize the schedulers feasible solution. It captures the value of the interactions between reaction severity, product yields and properties, both within and between the process units by solving a chemical engineering model that can be understood and maintained by a process APC engineer or scheduler. The user interface is the RefineryProfitMeter [RPM]™ which is designed to support and integrate the refinery optimization activity of the planners, schedulers, operations and APC engineers.
Our modeling innovation permits [RMO]™ to simultaneously optimize process units from the crude feed out to the product pools in real time. By optimizing out to product pools with a model that process engineers can understand we avoid the major problems that afflict all other RTO technologies; 1) excessive complexity; and 2) inevitable optimizing conflicts between Unit RTOs, and optimizing conflicts between the Unit RTOs and the Planning Optimum, both of which are caused by use of intermediate stream shadow prices in unit RTOs. In traditional refinery Unit RTO applications these conflicts always lead to either abandonment of the applications or; 1) clamping the Unit RTO solution and loss of potential benefits; and 2) tuning the shadow prices of intermediate product streams to make the Unit RTO achieve a desired behaviour, thus undermining the economic incentive for Unit RTO. [RMO]™ overcomes all of these problems and also the model shortcomings of the linear planning LP and MVCCs with a simplified, non-linear, open-equation, chemical engineering model that uses only product prices in its objective function and is about the size of a single period of the planning model.
- [RMO]™ calculates it’s contribution to refinery profit in real-time
- Up to an additional 50% reduction in the GAP between scheduled and achieved profit
- We will guarantee sustainable profit
For more information contact firstname.lastname@example.org.