Optimization of pyroliysis of polypropylene and polyethylene based plastic waste become an alternative oil fuel using bentonite catalyst

¹ Department of Chemical Engineering, Faculty of Engineering, Widya Mandala Surabaya Catholic University, Surabaya 60114, Indonesia
² Research Center for Chemistry, National Research and Innovation Agency, Jakarta 10340, Indonesia
³ Professional Engineer Program, Widya Mandala Surabaya Catholic University, Surabaya 60114, Indonesia

^* Corresponding author: suratno.lourentius@ukwms.ac.id

Abstract

The conversion is accomplished by pyrolyzing plastic bag waste at relatively low temperatures, around 50-225OC, and using a bentonite catalyst. The four products are alternative oils consisting of gasoline, kerosene, diesel, and non-condensable gas. The pyrolysis procedure is as follows: (a). 3 kg of chopped plastic waste mixed with a mass fraction of bentonite catalyst of around 0.035-0.0125 of the weight of plastic waste and then put into the pyrolysator; (b). the pyrolysator is heated with 1.5 kg of liquid petroleum gas (LPG) for 2-3 hours at a temperature ranging from 50-225oC; (c). pyrolysis results are stored separately in 3 pots: gasoline, kerosene, and diesel; (d). to clarify pyrolysis results by adsorption using a sand filter. The variables studied were the polypropylene (PP) and polyethylene (PE) plastic materials type and the effect of the mass fraction of bentonite catalyst ranging from 0.035 to 0.125. The research obtained relatively good results as follows. Pyrolysis of 3 kg of PP plastic waste with the mass fraction catalyst of 0.100 yielded 44.00% alternative gasoline, 10.76% alternative kerosene, 21.07% alternative diesel, and the remaining non-condensable gases. The flash (ASTM D7094) points of alternative gasoline, alternative kerosene, and alternative diesel are 84˚C, 68˚C, and 100˚C, respectively. The calorific value of each fuel product is 10,970 cal/g for alternative gasoline, 10,965 cal/g for alternative kerosene, and 10,816 cal/g for alternative diesel. In addition, the pyrolysis of PE plastic waste with the mass fraction of catalyt of 0.100 produced a yield of 27.65% for alternative gasoline, 17.11% for alternative kerosene, and 43.79% for alternative diesel, and the remaining was non-condensable gases. The respective flash points (ASTM D7094) of alternative gasoline, alternative kerosene, and alternative diesel are 84˚C, 70˚C, and 98˚C. The calorific values are alternative gasoline 10,979 cal/g, alternative kerosene 11,008 cal/g, and alternative diesel 11,027 cal/g.