Characterization and Use of Char Produced from Pyrolysis of Post-Consumer Mixed Plastic Waste

Abstract

In this work, the pyrolysis of post-consumer mixed plastic waste (polypropylene (PP), polystyrene (PS) and polyethylene film (PE)) is carried out. The solid product of the pyrolysis is characterized and tested for its use as adsorbent of lead present in aqueous media. The pyrolysis temperature has a great influence on the solid product yield, decreasing when the temperature increases. The highest yield to solid product obtained is from the pyrolysis of film at lower temperature (450 °C), reaching almost 14%. The results of product solid characterization reveal that the carbon, hydrogen and nitrogen content decreases with increasing pyrolysis temperature. Furthermore, both the ash and the volatile content are related to the pyrolysis temperature. The ash content is higher when the pyrolysis temperature is higher, while when the temperature increases, a solid product with lower volatile content is obtained. In respect to specific surface area, a higher pyrolysis temperature improves the properties of the solid product as an adsorbent. The adsorption capacity increases as the pyrolysis temperature increases, with the highest value of 7.91 mg/g for the solid obtained in the pyrolysis at 550 °C. In addition, adsorption capacity increases as the initial concentration of lead rises, reaching a maximum value close to 26 mg/g for an initial concentration of 40 mg/L. The Sips model is the one that best reproduces the experimental results of the adsorption process equilibrium study.

Pyrolysis of polypropylene plastic waste into carbonaceous char: Priority of plastic waste management amidst COVID-19 pandemic

“…There are several lists of char potential applications is extended also to less traditional materials ( Martín-Lara et al, 2021 ), including char-based fuel briquettes ( Harussani et al, 2021b ), raw materials for fabrication of graphene and its derivatives ( Miandad et al, 2019 ), nano-catalysts, adsorbent materials, nano-fillers for composite application ( Sogancioglu et al, 2020 ), sensors ( Chaudhary et al, 2021 ; Spanu et al, 2020 ) and supercapacitors ( Pandey et al, 2021 ; Vivekanandhan, 2018 ).…”

“…Pyrolysis char can be exploited for a variety of environmental applications. Considering the features and qualities of the char are dependent on the composition of the materials to be pyrolysed, the application of the solid product generated also depended on it ( Martín-Lara et al, 2021 ). Due to its high characteristics including surface area and porosity, this product is most commonly used as an adsorbent material.…”

A review on Transforming plastic wastes into fuel

“…Char as a by-product is formed due to (1) slow heating at a low temperature (2) longer residence time. This by-product has certain advantages like being used as an adsorbent in water treatment to remove heavy metals through an upgrading treatment [2], its low sulphur content makes it usable as a fuel as the calorific value of char is about 18.8 MJ/kg, and can be used in laying of roads and building materials [51], char-based sensors and supercapacitors [52,53,54,55]. The pyrolysis of PVC and PET compared to polyolefins and PS produced a large amount of gases.…”

Synthesis and efficient use of low‐cost natural red clay catalyst for the production of upgraded fuel oil using pyrolysis of waste expanded polystyrene and in situ vapour phase hydrogenation

“…5 The solid residue obtained from the pyrolysis process is very low amount, and it may be used as fuel, as an adsorbent, or even as a soil amendment. 6 The pyrolysis process does not require intense sorting process of feed materials, as it is needed in the recycling method. 5 In addition, various products from waste plastic pyrolysis could be achieved by controlling various factors such as catalyst choice, reactor design, and process parameters.…”

“…Furthermore, pyrolysis gas can be used for electricity generation in gas turbines and for direct firing in boilers without any flue gas treatment 5 . The solid residue obtained from the pyrolysis process is very low amount, and it may be used as fuel, as an adsorbent, or even as a soil amendment 6 . The pyrolysis process does not require intense sorting process of feed materials, as it is needed in the recycling method 5 .…”