ออกซิเดทีฟดีซัลเฟอไรเซชันของไพโรไลซิสแนฟทาโดยใช้ไฮโดรเจนเปอร์ออกไซด์และถ่านชาร์จากยางรถยนต์ใช้แล้ว / ดุษฎี บัณฑิตย์ = Oxidative desulfurization of pyrolysis naphtha using hydrogen peroxide and char derived from used tire / Dusadee Bunthid
This article studied the oxidative desulfurization of pyrolysis naphtha using hydrogen peroxide and char derived from used tire. The maximum yield of the pyrolysis naphtha was obtained from the used tire pyrolysis without catalyst at 400℃ for 10 min under nitrogen and hydrogen atmosphere. Each gas was flowed through a pyrolysis reactor at a rate of 0.1 L/min. However, the obtained pyrolysis oil consisted of sulfur compounds derived from the vulcanizing agents during vulcanization process of tire production. These sulfur compounds analyzed by using a gas chromatograph equipped with a flame photometric detector (FPD) composed of thiophene and derivatives of thiophene and benzothiophene. The oxidative desulfurization (ODS) is an attractive technique to reduce the sulfur content in oils due to low energy consumption during operation. Thus, this technique was applied to decrease the sulfur content in the naphtha derived from used tire pyrolysis. The pyrolysis char, one of pyrolysis products, was taken to enhance the sulfur reduction capacity of ODS process up to 60% because it could simultaneously promote the oxidation and adsorption of the sulfur compounds. The addition of formic acid in the presence of hydrogen peroxide at pH 0-4 increased the sulfur removal up to 70%. This could be explained that formic acid reacted with hydrogen peroxide to produce performic which is the highly oxidizing agent, resulting in the higher sulfur removal in the pyrolysis naphtha. Moreover, it was found that the use of surface-modified char using acids and hydrogen peroxide in the presence of formic acid also increased the sulfur reduction in pyrolysis naphtha to ca. 75%.
