Thermo-catalytic degradation of different plastics to drop in liquid fuel using calcium bentonite catalyst

Abstract

Thermal and catalytic pyrolysis of individual plastics such as polypropylene (PP), low-density polyethylene (LDPE), high-density polyethylene (HDPE), and mixture of all three plastics (PPâ+âLDPEâ+âHDPE) were carried out in the presence of calcium bentonite as catalyst in a batch reactor to obtain suitable liquid fuel. The dependencies of process temperature, effect of catalyst, feed composition on yield of the fuel fraction were determined. The major product of both thermal and catalytic pyrolysis was condensable fraction in the temperature range 400â550 °C. The reaction rate, quality and quantity of the major products changed with change of temperature and catalyst concentration. The highest yield of pyrolysis liquid product was 88.5 wt% from PP, 82 wt% from LDPE, 82.5% from HDPE and 81 wt% from mixed plastics at 500 °C with 1:3 catalyst to plastic ratio. The oil obtained in this process was analyzed using FTIR and GCâMS for its composition. Fuel properties of the oil are evaluated to understand its uses as a fuel or chemical feedstock.