Short-Term Scheduling of Refinery Crude Oil Operations

Abstract

Scheduling of crude oil unloading and loading operations is an important optimization problem for minimizing the significant costs at the front end of a refinery. The scheduling problem involves finding the optimal operation of crude-oil unloading from vessels, its transfer to storage tanks, and determination of charging schedule for each crude-oil mixture to the continuous distillation units. In this work, we propose a simplified state-task-network (STN) based formulation to address the problem of short-term scheduling of crude oil operations using unit-specific event-based continuous-time representation by incorporating explicit storage tasks for handling material transfer from storage and charging tanks. Constraints are developed for different cases corresponding to material flow in a tank based on (i) whether bypassing is allowed or not, (ii) whether crude mixing is allowed or not, and based on (iii) whether simultaneous input and output is allowed or not. The proposed model is applied to a few benchmark examples from literature giving better results with improved objective functions compared with the results reported in previous works.

A cost‐effective model for the gasoline blend optimization problem

“…Several papers have already studied the multiperiod mixing of crude oil or refined petroleum products in blending tanks and considering the issue of (non-)simultaneous input and output flows. [3][4][5][6] Other important contributions assumed that the blending process is carried out in tankless inline blenders, and focused on the simultaneous optimization of gasoline recipes and the scheduling of blending and distribution operations 7 developed a multi-level integrated approach to coordinate the short-term scheduling of blending operations with nonlinear recipe optimization. At the upper level, a nonlinear problem is solved to determine blending recipes and product volumes for the scheduling level.…”

“…LP relaxation bound 5 {15,147.24 (1) , 17,918.26 (2) , 18,555.23 (3) , 20,286.52 (4) , 21,046.93 (5) }. Tables 3 and 4 include the product recipes selected at the best solutions found for the SP and MP instances of Examples 1-12, respectively.…”

Efficient Approach for Scheduling Crude Oil Operations in Marine-Access Refineries

“…∑ ‫ܭܹ‬ , ∈ = 1), then it has a finite size by Eq. (14). The parameters ‫݇ݏ{‬ , ‫݇ݏ‬ ௫ } stand for the minimum and maximum allowed sizes for lots ik ∈ IK.…”

Reception, mixture, and transfer in a crude oil terminal

“…The objective is to maximize the profit margin associated with purchasing and refining of crude oil. Lee et al (1996), Yadav & Shaik (2012) and consider the scheduling problem that deals with the optimal operation of crude oil unloading from vessels, its transfer to storage tanks and determination of a charging schedule for each crude oil mixture to the distillation units, minimizing crude unloading and inventory costs. Hamisu et al (2013) introduce the concept of shutdown units penalty and tank to tank transfer.…”

“…However, the reformulated linear constraints are not sufficiently precise to force the concentration of the outlet flow from a storage tank to be equal to the A c c e p t e d M a n u s c r i p t concentration inside the tank, Li et al (2011). Yadav & Shaik (2012) propose a state-task-network (STN) based formulation using unit-specific event-based continuous-time representation. The formulation results in a MINLP model that is relaxed to a MILP by dropping the nonlinear crude oil mixture constraints.…”