Energy Potential of Plastic Waste Valorization: A Short Comparative Assessment of Pyrolysis versus Gasification

Abstract

Plastics are abundant and have a high energy content making their use in energy applications attractive. This article presents a review on plastic waste (PW) management by pyrolysis and gasification, which are two routes of thermochemical conversion (TCC) techniques. The conversion of PW and the application of its converted products are important steps towards reducing reliance on fossil fuel, enhancing closed-loop recycling of materials and circular economy. The review presented herein also focuses on product distribution and yields with emphasis on the energy content and potential integration to energy systems and grids. It is found that pyro-oils have properties similar to conventional fuels such as diesel and can partially substitute fossil fuels. In fact, the energy content of PW pyro-oils obtained by various researchers range from 41.10 -46.16 MJ kg -1 , which are close to the heating values of conventional fuels, thus are potential candidates for fuel applications. Typical treatment post conversion is also conducted to maintain the quality of the oil produced and the removal of sulphur content to conform with market standards. On the other hand, syngas produced during gasification possesses a lesser potential for fuel applications as its energy content may reach values as low as 20 MJ kg -1 in

Molecular Characterization of a Mixed Plastic Pyrolysis Oil from Municipal Wastes by Direct Infusion Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

“…This (thermo)­chemical recycling can be divided in three branches: pyrolysis, gasification, or hydrocracking. Pyrolysis has gained importance due to having better advantages toward environmental pollution and the minimization of carbon monoxide and carbon dioxide emissions compared to other thermochemical ones. ,− This pyrolysis process produces gas, oil, and a char product . The oil fraction can be then valorized as fuels or reused as monomers after steamcracking.…”

Pyrolysis of High-Density Polyethylene in a Fluidized Bed Reactor: Pyro-Wax and Gas Analysis

“…Pyrolysis is one of such conversion techniques that can be applied to convert plastics and waste into value-added products including fuels, chemicals, wax, and oil. Pyrolysis is defined as an advanced thermochemical conversion (TCC) technology that could degrade PW feedstock using inert media such as N 2 , Ar, or He gases under the influence of operating temperatures ranging between 350 and 900 °C . Thus, pyrolysis is a promising technique to simultaneously address energy demands and PW management. ,, Readers are referred to the study by Al-Salem et al for a detailed review on the influence of operating temperatures and product evolution from various PW feedstock, in addition to types of reactors used for pyrolysis.…”

Closing the Carbon Loop in the Circular Plastics Economy

“…In gasification, plastic wastes are partially oxidized by reacting them with gasification agents such as oxygen, steam, and air at temperatures in the range of 500-1300 °C to generate synthesis gas (syngas) consisting mainly of carbon monoxide and hydrogen. [470][471][472][473][474][475] Produced from any kind of carbon sources spanning biomass, natural gas, coal, and plastic waste, syngas serves as a raw material for sustainable fuels and chemicals, including methanol as well as synthetic hydrocarbon lubricants and olefin monomers, both of which are formed in a Fischer-Tropsch process stage after gasification. In particular, cogasification of plastics with coal and biomass as well as pyrolysis coupled with inline reforming are considered to be promising valorization routes.…”