High Calorific Value Fuel from Household Plastic Waste by Catalytic Pyrolysis

Plastic waste pollution causes several impacts on the environment, so its proper disposal is very essential. On the other hand, petroleum resources are vanishing due to high demand of fuel for growing population and limited resources in India. So, there is a need to save existing resources and find an alternative source for fossil fuels. We can convert household plastic waste into petroleum products by pyrolysis method. In the present study, lab scale borosilicate pyrolysis reactor set up was designed for plastic waste treatment. Major components of household plastic waste are HDPE, LDPE and PP material, so were used in pyrolysis. Shredding, washing and drying of plastic waste was done manually. Pyrolysis experiments were carried out for 100g of HDPE, LDPE and PP waste with and without catalyst. Temperature and reaction time were optimized for each type of waste. Different catalysts like alumina, scolecite, dolomite, ceramic powder, white cement, sand and red brick powder were tried in the pyrolysis process. As dolomite yielded maximum liquid fuel and is cost effective, it has been used in pyrolysis experiments with different catalysts to feed ratios. Liquid fuel obtained for HDPE, LDPE and PP enhanced from 72%, 73% and 84% to 82%, 83% and 85% respectively, by using 10% dolomite. For mixed plastic waste, liquid fuel obtained was about 72.96% without catalyst and 82% with 10 % dolomite. Liquid fuel was characterized for GC-MS, FTIR and calorific values. Results showed the presence of alkanes and alkenes in major quantity and increase in concentration of low molecular weight hydrocarbon fractions (C₁₀-C₂₅) in the liquid fuel. Liquid fuel obtained from HDPE, LDPE and PP by using 10% dolomite showed higher calorific values (43000-46000 kJ/kg) as compared to that of without catalyst (40000-42000 kJ/kg). This liquid fuel can be used as a fuel in different industrial sectors.