Optimization Studies on Hydroisomerization and Hydrocracking of Long Chain n-Paraffins in Tubular Fixed-Bed Reactors

Optimization studies on hydroisomerization and hydrocracking of long chain n-paraffins, n-C16, n-C28 and n-C36, in a tubular fixed bed reactor is implemented. The process is numerically simulated and the optimization studies are conducted using Genetic Algorithm (GA) and Response Surface Methodology (RSM). The impact of the operating variables (temperature, liquid hourly space velocity (LHSV) and specific external surface area of the catalysts) on the isomer contents of the product were comparatively investigated by the mentioned methods. The optimal value of isomerized content of the product was obtained to be 47.64% and 51.01% via GA and RSM, respectively. The corresponding values of LHSV and specific surface area were found to be the maximum values in the specified intervals, i.e. LHSV=3.68 hr-1 and Sb=234 m2/g; and the value of temperature was calculated 320.39˚C and 340.24˚C using GA and RSM, respectively. The results of the GA are more precise due to the use of mathematical model as a part of this approach.