چكيده به لاتين
Abstract:
Gas oil was oxidized by means of hydrogen peroxide as oxidizing agent and formic acid as catalyst under specific condition to investigate of the effect of different parameters such as solvent to feed ratio,the number of extraction unit,time and temperature relationship to the amount of extractive desulfurization and oil recovery from feed, and it was extracted by acetonitrile according to the design of expert based on response surface methodology by box-Behnken method by usage of design expert ver.7 software in the following of the work.
Analysis variance gave a model for desulfurization and oil recovery which shows the effect of solvent to feed ratio and the number of extraction unit. Time which has no significant impact to the amount of desulfurization and oil recovery, shows that the highest amount of mass transfer aoccurs before 20 minutes and during this time the organic and aqueous phases have been almost balanced.
In the following,the solvent to feed ratio,the number of extraction unit and the time were reported 1, 3.22 and 20 mintues respectively according to the models which have been provided by optimum operating conditions for desulfurization and oil recovery from feed. The number of extraction unit must be integer therefore the amounts of desulfurization and oil recovery from feed were compared and reported for the 3th and the 4th stages.
Some experiments were conducted for different temperatures such as 20 c,35 c and 55 c under operating condition of solvent to feed ratio equal to 1,the number of extraction unit equal to 1 during 20 minutes in order to investigate the effect of temperature on extraction which showed the reduction in the amount of desulfurization and increasing in oil recovery from feed.
The effect of temperature was investigated under optimum operating condition as well which showed the effect of increasing in temperature is independent from the effect of increasing in the number of extraction unit.
Experiment was done by recycled solvent as well under optimum operating condition in order to study the efficiency of recycled solvent which showed that oil recovery from feed increases by usage of recycled solvent in comparison of usage of fresh solvent ,although the amount of desulfurization doesn’t change in both usage of recycled and fresh solvent.
Processes of extractive,oxidative and oxidative/extractive desulfurization were compared with eachother under the same experimental condition which the results showed oxidative/extractive desulfurization is the best operatiom among of other processes.
Keywords: extraction of sulfones from gas oil,oxidative desulfurization process (ODS),optimization by design of expert based on response surface methodology,effect of recycled solvent on amount extraction
