A study on thermo-catalytic degradation for production of clean transport fuel and reducing plastic wastes

Both the landfilling and incineration processes of plastic waste management system are identified as sources of pollutant gas emitters. Reprocessing is also uneconomical in comparison to the virgin plastic products in terms of commercial values due to polymeric contamination. This article studies the thermo-catalytic conversion processes waste plastics. The reaction conditions and the quantification of types of catalysts used for the conversion processes influenced the quality of the resultant hydrocarbons. Obtaining higher yield of conversion and transport grade fuel require more investigation to adapt this technical process as one of the effective alternative resources for fuel production. Thermo-catalytic process resolves the problem of halogen contents in the PVC type plastics by converting them into residues with the use of NaHCO3 and AgNO3 which capture chlorine type products from the gaseous hydrocarbons. Addition of catalysts in the convenient reactor reduces the requirement of higher temperature operations like thermal cracking processes and produces more liquefied products. It has been observed that, the aromatic plastic contents should be observed during the conversion process to obtain fuels based on allowable aromatic contents according to the fuel standards and emission regulations implemented in respective regions. The temperature of the process need to be controlled as per the boiling points of the mixture contents to avoid formation of vapor in the reactor which could causes sticky adherence to the reactor walls. A continuous liquid fractionating distillation process can reduce the formation of light gases in the yield. It was also found that the mixture of LDPE, HDPE, PP and PS yield 87.19% fuel with 20 wt% ZnO catalyst at 200 – 400 °C in a steel reactor. These fuels can be used directly in the automotive engines or can be retreated in the refineries to divide into gasoline and diesel fuels as per carbon chains. Since the plastic feedstocks do not contain any sulfur components the produced fuel can be treated as clean enough. Thus the fuels produced from this process can be considered as one of the potential alternative resources of fuel production resulting into an effective reduction of plastic wastes in a country.