When a disturbance is introduced into a chemical plant, measurements are taken and control actions are implemented to compensate for the effects of the disturbance decades, several techniques for CV selections have been reported. Most of these techniques require process models to determine CVs offline and largely depend on the ability to obtained and a feedback input (manipulated variable) was derived. The performance of the proposed approach was tested using case stud disturbance with the base case model giving an optimal profit of $56,696,407 while the proposed approach yields $50,523,054, translating to 10.888 % loss. The percentage loss for the second, third and fourth cas respectively. The results obtained have shown that the idea presented was able to effectively deal with the situation at hand with percentage loss within a reasonable degree ABSTRACT Problem formulation as mixed integer nonlinear programming (MINLP) is one of the most challenging task in refinery scheduling optimization. In most of the work reported in refinery scheduling, uncertainties from design point of view predominate. However, t need to consider operational uncertainties (disturbances) as they affect the accuracy and robustness of the overall schedule. This study proposed a novel approach under optimizing control (SOC) framework under uncertain conditions. The goal is to maintain global optimum by controlling the gradient of the cost function at zero via approximating necessary conditions of optimality (NCO) over the whole uncertain parameter space. A regres revenue (profit) as a function of independent variables using optimal operation data was

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Slug translational velocity, described as the velocity of slug units, is the summation of the maximum mixture velocity in the slug body and the drift velocity. Accurate estimation of this parameter is important for energy-efficient design of oil and gas pipelines. A survey of the literature revealed that existing prediction models of this parameter were developed based on observation from low viscosity liquids (of 1 Pa.s or less). However, its behaviour in pipes transporting higher viscosity oils is significantly different. In this research work, new data for slug translational velocity in high-viscosity oil-gas flows are reported. Scaled experiments were carried out using a mixture of air and Mineral oil of viscosity ranging from 0.7 to 6.0 Pa.s in a 17-m long horizontal pipe of 0.0762 m ID. Temperature dependence of the oil's viscosity is given as μ=−0.0043T3+0.0389T2−1.4174T+18.141. The slug translational velocity was measured by means two pairs of two fast-sampling Gamma Densitometers with a sampling frequency of 250 Hz. For the range of experimental flow conditions investigated, increase in liquid oil viscosity was observed to strongly influence slug translational velocity. A new predictive correlation incorporating the effect of viscosity on slug translational velocity was derived using the current dataset and incorporating those obtained in literature with oil viscosity ranging from 0.189–6.0 Pa.s for horizontal flow. A comparison by statistical analysis and validation and of the new closure relationship showed a remarkably improved performance over existing correlations.