The Preparation Of Potassium Ferrate And The Application On Diesel Desulfurization

Environmental protection is one theme in the 21st century,desulfurization has been animportant and stringent mission. At present, the development of new technologies aboutnon-hydrogenation desulfurization is being studied in all countries. The oxidationdesulfurization is one of research hotspot. Potassium ferrate is a new type of strong oxidant,which bears many advantages such as rapidity, non-residual toxicity and non-secondarypollution. Hence, it exhibits great potential in the oxidation desulfurization.In this thesis , potassium ferrate was synthesized by the hypochlorite oxidation method.The studies display that the reaction has the best effect at 0℃when the molar ration ofpotassium hypochlorite and ferric nitrate is 3, and the weight ratio of stabilizer and ferric saltis 0.043. Meanwhile, the ferric salt is gradually added in 60 minutes, and the reaction is keptfor 45 minutes at 0℃. The purity quotient of product reaches 95% after the purification isconducted only one time, which provide some data for realizing the industrializationproduction of potassium ferrate.The desulfurization studies were conducted by adding above potassium ferrate to themodel mixture consisting of n-butyl mercaptan and cyclohexane. The optimum conditions areas follows: the pH value is 4.0, the ratio of potassium ferrate and model mixture is 0.003g/mL, the ultrasonic time is 7 minutes, the reaction temperature is 50℃, the impulse time is 4seconds, and the mixture is extracted for 45 minutes by using isometrical methanol. Theresults derived from the standard curve of UV-vis spectra show that the desulfurizationefficiency reaches 85 %, which is similar to result from the gas chromatograph.The desulfurization studies were also conducted by adding potassium ferrate to the baddiesel. The optimum conditions are similar to those of above-mentioned system, but theaddition value of potassium ferrate is 0.04 g/mL for the diesel, and the extraction time is 60 minutes. The results of spectrophotometry display that the absorbance of diesel reaches thesmallest value when the absorbance of the related extraction solution reaches the largest value.The desulfurization efficiency was characterized by X-ray fluorescence spectrometer and gaschromatography after extraction, and the results show that the rate of desulphurizationreaches72.0 %. Based on above conditions, the yield of diesel gets to 91.2 %.