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Gasoline blending is of pertinent importance in refinery operations owing to the fact that gasoline gives about 60 -70 % of the refinery profit. The blending process is essential to obtain gasoline in the demanded quantities and ensure property specifications are met. Two model equations, multivariable nonlinear and multivariable exponential are proposed in this study which are useful in predicting three significant properties of a motor gasoline: research octane number, reid vapour pressure and specific gravity. Gasoline blend data obtained from four different streams: straight run gasoline, straight run naphtha, reformate and fluidized catalytically cracked gasoline have been subjected to multivariate regression analysis with the aid of a statistical software to ascertain the fitness of the proposed equations in predicting the research octane number, reid vapor pressure and the specific gravity of the resulting premium motor spirit. The results of the regression analysis showed that the nonlinear multivariable models proposed gave a good fit as evidenced by the value of the coefficient of determination R 2 = 0.988 & 0.994 for the research octane number, 0.853 & 0.883 for the reid vapor pressure and 0.988 for specific gravity. In conclusion, the proposed model equations were fit to the data, found to be adequate, and therefore could be used for prediction of the blend gasoline properties.

Abstract:Blends of starch (tapioca) and polypropylene were prepared in various wt/wt concentrations ranging from 100% polypropylene resins to 5:95, 10:90, 20:80, 30:70, 40:60, and 50:50 wt% starch to wt% polypropylene blends. Then the rheological and mechanical properties of the resulting blends were determined using Plastometer and Universal Testing Machine respectively. Tensile strength, percentage elongation, flexural modulus, Izod impact, vicat softening temperature and melt flow index tests were carried out according to American standard for testing and materials procedure. The melt flow index was found to decrease linearly with increasing starch concentrations up to 30 wt% starch to wt% plastic, beyond which no flow was observed. The presence of starch in polypropylene was found to have positive effect on some of the mechanical properties like flexural modulus and Izod impact strength, whereas a negative impact was obtained on the tensile strength and percentage elongation. It was observed that higher starch loadings above 30% reduced the mechanical properties while lower starch loadings below 30% improved some mechanical properties. In addition, higher starch loadings above 30% does not favor the melt flow index and the Izod impact strength since there was no flow due to lower vicat softening temperature. Thus, with the aid of controlled incorporation of the starch additive, several properties of the modified polypropylene specimen could be enhanced.

Gasoline is a highly flammable liquid derived mainly from crude oil that is used primarily as an energy source for internal combustion engines. To be competitive, gasoline must meet certain standards of high quality such as Octane number, Ried Vapor Pressure (RVP), and minimal environmental pollutions. This work aims at optimizing the production of a high-quality gasoline blend that meets the Octane number, RVP, Economic and Environmental standards, using varying oxygenates. The gasoline blending was executed by employing the linear programming solver application in Microsoft excel using four blending components namely the Fluid catalytic cracking gasoline (FCCG), Straight run naphtha (SRN), Straight run gasoline (SRG), Butane, and varying Oxygenates. The Blending process was simulated in ASPEN HYSYS simulation software, and the output product was tested for pollutant emissions in the same software. The selected blend was further optimized to minimize emission using the Response Surface Methodology in MINITAB version 18. Upon gasoline blending optimization and emissions testing, four blends met our specifications namely, the MTBE blend, the ETBE-blend, the Ethanol-blend, 1-Butanol blend. After a simple weighting method, the Ethanol was selected as the optimal blend having a net savings of 67.09 tons/year and 476tons/year of NOx and TVOC emissions respectively, a net increase of 16.35 tons/year of TTC emissions. The Blend was further optimized using RSM. The optimization results showed that SRG was the main contributor to NOx emissions, ethanol was a significant contributor to the TTC emissions while Butane had no effect of both emissions. The new optimized ethanol-blend gave a further 90.42% reduction in NOx emissions, and 67.85% reduction in TTC emissions, but with an increased amount of ethanol in the blend. The economics of a gasoline blending plant was evaluated, giving a pay-back period of 2.46 year, NPV @ 10th year of $177.6 million, an internal rate of return of 57.36%, and a profitability index of 3.04. This showed that the process would be highly profitable.

Abstract:The glaring need for energy management in a petroleum refining industry is as a result of significant refinery energy costs, typically 40-50% of operating costs. Consequently, energy auditing is frequently carried out to identify energy management opportunities for higher profitability. Hydrogen management in a refining plant by means of the hydrogen pinch analysis approach aimed at identifying the optimum hydrogen network has been recognized as an effective way of optimizing the processes. The numerous benefits of hydrogen management include maximum processing revenue as a result of reduced hydrogen system operating costs and production benefits, minimum capital investment, reduced carbon dioxide emissions, and more importantly, up to 20% cost savings from energy efficiency improvements. Hydrogen pinch technology has been employed in this study to discover optimum hydrogen distribution systems which can be a potential energy management opportunity in a refining industry. The goal was to identify shortcomings in the hydrogen distribution of the system so as to improve the energy utilization of the plant. Analysis of the case study resulted in identification of optimum hydrogen target for the system. Achieving the target will reduce the power consumption of the catalytic reforming unit by 10.8% and also help to conserve hydrogen use by more than 20%. Implementation of suggestions for efficient utilization of energy made will increase the profit as well as the operating costs. However, there will be annual increase in marginal revenue as the profit is considerably greater than the operating costs. The payback period and return on investment (ROI) of these suggestions are less than 3yrs and 28% -44% (depending on the option adopted) respectively. Another significant advantage of the project is that it will reduce the gas flaring and helps prepare the refinery for future environmental challenges.