The effects of activated Al2O3 on the recycling of light oil from the catalytic pyrolysis of waste printed circuit boards

The effects of employing activated Al2O3 during the catalytic pyrolysis of waste printed circuit boards (WPCBs) are investigated, focusing on the recycling of light oil. Variations in the pyrolysis process are studied through analysis of the phase distribution, water content and boiling point fractions of the resulting products. Product composition and carbon number distribution are analyzed using gas chromatography techniques. The use of activated Al2O3 increases the light oil fraction and also reduces the quantity of brominated products formed. It was determined that the best yield of light oil and most efficient debromination resulted from catalytic pyrolysis at 600 degrees C. Applying catalyst-to-feed ratios in the range of 1.0-1.5 also maximizes the yield of light oil. The major oil fraction resulting from catalytic pyrolysis has a boiling point range of 0-250 degrees C and carbon number range of C6-C9, showing for use as a potential fuel after suitable treatment such as hydrogenation. At a higher catalyst-to-feed ratio of 2.0, activated Al2O3 generates a high proportion of light oil fractions containing a significant quantity of chemicals such as phenol (52.67% at 600 degrees C), although an overall lower yield of oil is obtained. The oil produced in this manner may also be used as a raw material feedstock for the production of various other useful chemicals. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.