PYROLYSIS OF USED SUNFLOWER OIL IN THE PRESENCE OF SODIUM-CARBONATE BY USING FRACTIONATING PYROLYSIS REACTOR

Pyrolysis of used sunflower oil was carried out in a reactor equipped with a fractionating packed column tin three different lengths of 180, 360 and 540 mm) at 400 and 420 degrees C in the presence of sodium ca rbonate (1, 5, 10 and 20% based on oil weight) as a catalyst. The use of packed column increased the residence times of the primer pyrolysis products in the reactor and packed column by the fractionating of the products which caused the additional catalytic and thermal reactions in the reaction system and increased the content of liquid hydrocarbon s in gasoline boiling range. The conversion of oil was high (42-83 wt. %) and the product distribution was depended strongly on the reaction temperature, packed column length and catalyst content. The pyrolysis products consisted of gas and liquid hydrocarbons, carboxylic acids, C O, CO2, H-2 and water. Increase in the column length increased the amo unt of gas and coke-residual oil and decreased the amount of liquid hy drocarbon and acid phase. Also, increase of sodium carbonate content a nd the temperature increased the formation of liquid hydrocarbon and g as products and decreased the formation of aqueous phase, acid phase a nd coke-residual oil. The major hydrocarbons of the liquid hydrocarbon phase were C-5-C-11 hydrocarbons. The highest C5-C11 yields (36.4%) w as obtained by using 10% Na2CO3 and a packed column of 180 mm at 420 d egrees C. The gas products included mostly C-1-C-3 hydrocarbons. (C) 1 998 EIsevier Science B.V. All rights reserved.