Characteristics Study of Liquid Fuel From Pyrolysis of Polyethylene Plastic Waste

Abstract

Polyethylene plastic waste was selected as pyrolysis feedstock. This plastic waste is not recycled mechanically and is abundantly available at the landfill. The plastic-type of low and high-density polyethylene (LDPE and HDPE) was converted into pyrolysis liquid fuel (PLF). This study aims to characterize the physicochemical properties of the PLF to attest to its potential use as a kerosene fuel for household purposes. The PLF was generated from the collecting of household plastic waste through pyrolysis. A design of the simple non-catalytic semi-batch reactor was applied to pyrolyze this plastics waste into PLF at about 360 °C and isothermal residence time up to about 1 hour. The high enough PLF yield of 50.3% (v/w) and 77.0% (v/w) was obtained from LDPE and HDPE plastics waste, respectively. The dominance of alkane (CH) and alkenes (C=C) functional groups of PLF and commercial kerosene fuel was analyzed by the Fourier transform infrared spectroscopy (FT-IR) spectra. Gas Chromatography-Mass Spectrometer (GC-MS) analysis indicates that most PLF substances in the form of tetradecane (C14H30), pentadecane (C15H32), hexadecane (C16H34), octadecene (C18H36), eicosane (C20H42) are similar to commercial kerosene substances. The combustion properties of this PLF are so similar to the standard values of the kerosene fuel. The combination of thermal efficiency, ηT using wick stove and PLF from LDPE and HDPE of 45.66% and 32.37%, respectively was obtained in this work.

Inexpensive Volcanic Ash Catalyst for Pyrolysis of Plastic Waste into Fuel Using Sequential Thermo-Catalytic Reactor

“…The ash point and auto ignition point of LF are related to its density and viscosity, the lower content of hydrocarbon fraction (< C 20 ) and higher volatile aromatic content of LF will decrease its density and viscosity. The ash point and auto ignition point of LF tends to decrease as the density and viscosity decrease [24,30,31]. This is in line with the results of this work, that the use of an amount of volcanic ash catalysts produces LF with relatively low density and viscosity, which in turn reduces the ash point Meanwhile, kerosene has a ash point of 38-52°C and an automatic ignition point (temperature) of 210°C [31].…”

“…In addition, the pyrolysis process at low to moderate temperatures produces more LF than the gaseous product. The use of a large enough condenser capacity enforces more condensation of condensable gaseous to produce more LF as also reported in previous research studies [8,24]. The more amount of VA catalyst used during the pyrolysis operation, the higher the yield of LF produced.…”

“…Measurement of LF density was carried out at a temperature of 20 o C using a density meter and volumetric glassware. The LF energy content (HV) was calculated using the commonly used correlation based on its density and viscosity [24]. Gas chromatography combined with mass spectrometry (GC-MS) and Fourier transform infrared (FT-IR) LF spectral analysis was used to investigate the chemical composition and functional groups.…”

“…In this case, the use of a catalyst did not give a signi cant change both to the density and viscosity of LF. This could be due to the similarity in the content of aliphatic hydrocarbons (alkanes and alkenes) as major substances in LF [24]. However, the density and viscosity of the pyrolysis oil are still in the range of density and viscosity of commercial kerosene of 0.79-0.89 g/mL and 0.294-3.340 cP, respectively [31,32].…”

“…It was found that the LF viscosity from LDPE pyrolysis had a lower value than the LF viscosity from styrofoam pyrolysis. This was possible in the presence of an activated VA that could degrade double bonds and the length of the hydrocarbon chain into lower molecular weight in addition to the more aromatics contained in LF [24]. Lower fuel viscosity is required to obtain better fuel atomization in the formation of a smaller droplet size, which in turn results in good combustion [32].…”