Monitoring and Quality Control of Diesel Fraction Production Process

In this work the mathematical model of diesel fraction and atmospheric gasoil catalytic dewaxing process has been developed. Also the pattern of applying the created model to solving such problems as monitoring and quality control of diesel fraction production in the catalytic dewaxing process. It has been represented that to meet such challenges, the model should take into consideration thermodynamic and kinetic laws of hydrocarbon conversion on the catalyst surface, and instability factors that are specified by catalyst deactivation. The developed model allows controlling the quality of obtained diesel fraction depending on feed and temperature regime in the reactor. The value of model calculation absolute error does not exceed 2%, which corroborates the adequacy of the model to actual process. The computations using the model have shown that to provide the desired product yield (not less than 40% wt. of overall yield of the unit products) of programmed quality (cold filtering plugging point not higher than minus 34 degrees C for winter diesel fuels and not lower than minus 40 degrees C for arctic ones) at long-time catalyst operation (during 4 years), it is necessary to sustain the reactor temperature at the average level of 19 degrees C higher than when working with fresh catalyst. This must be done to compensate catalyst activity loss due to its deactivation.