Currently, most plastic waste stems from packaging materials, with a large proportion of this waste either discarded by incineration or used to derive fuel. Accordingly, there is growing interest in the use of pyrolysis to chemically recycle non-recyclable (i.e., via mechanical means) plastic waste into petrochemical feedstock. This comparative study compared pyrolysis characteristics of two types of reactors, namely fixed and fluidized bed reactors. Kinetic analysis for pyrolysis of SRF was also performed. Based on the kinetic analysis of the pyrolytic reactions using differential and integral methods applied to the TGA results, it was seen that the activation energy was lower in the initial stage of pyrolysis. This trend can be mainly attributed to the initial decomposition of PP components, which was subsequently followed by the decomposition of PE. From the kinetic analysis, the activation energy corresponding to the rate of pyrolysis reaction conversion was obtained. In conclusion, pyrolysis carried out using the fluidized bed reactor resulted in a more active decomposition of SRF. The relatively superior performance of this reactor can be attributed to the increased mass and heat transfer effects caused by fluidizing gases, which result in greater gas yields. Regarding the characteristics of liquid products generated during pyrolysis, it was seen that the hydrogen content in the liquid products obtained from the fluidized bed reactor decreased, leading to the formation of oils with higher molecular weights and higher C/H ratios, because the pyrolysis of SRF in the fluidized bed reactor progressed more rapidly than that in the fixed bed reactor.

EFB is a biomass waste primarily generated in Southeast Asia, and its pyrolysis enables both waste management and conversion into valuable products. In pyrolysis, the heating rate is a crucial factor; however, studies on its influence on EFB are extremely limited. This study investigates the pyrolysis characteristics of EFB by analyzing product properties based on reaction temperature and heating rate. TGA showed that the thermal decomposition of EFB begins at approximately 210 °C and is largely complete by 400 °C. Furthermore, kinetic analysis using TGA data, applying both differential and integral methods, revealed distinct trends. Through pyrolysis experiments using a fixed-bed reactor, the yield analysis of products under varying reaction temperatures and heating rates demonstrated that higher temperatures promote pyrolysis, leading to a decrease in biochar yield and an increase in gas product yield. For liquid products, a higher heating rate suppressed secondary reactions and led to an increase in the yield of the aqueous phase. Gas product characterization revealed that CO and CO₂ formation began simultaneously at approximately 270 °C. GC-MS analysis of the liquid products recovered under different pyrolysis conditions showed that most compounds contained oxygen, originating from hemicellulose, cellulose, and lignin. Additionally, FT-IR analysis of the biochar confirmed that oxygen-containing functional groups decomposed as pyrolysis progressed, and the presence of turbostratic carbon and crystallinity influenced by trace inorganic elements was identified.

Currently, most plastic waste stems from packaging materials, with a large proportion of this waste either discarded or used to derive fuel. Accordingly, there is growing interest in the use of pyrolysis in the context of chemically recycling non-recyclable (i.e., via mechanical means) plastic waste into petrochemical feedstock. The aim of this study is to use kinetic analyses to elucidate the pyrolytic properties of solid recovered fuel (SRF) produced using two types of reactors, namely, fixed bed and fluidized bed reactors. From the kinetic analysis, the activation energy corresponding to the rate of pyrolysis reaction conversion was obtained. In conclusion, we found that the pyrolysis occurs more vigorously in fluidized bed reactors compared to fixed bed reactors.

Rice cultivation generates a substantial amount of rice husks (RH) as agricultural waste from rice milling, which is not effectively utilized for environmentally friendly products. This study investigates the product yields and chemical characteristics of RH pyrolysis conducted at temperatures between 400 and 600 °C, at 50 °C intervals, with heating rates of 5, 10, and 20 °C/min. The highest liquid product yield (30.57%) was achieved at 600 °C under a heating rate of 20 °C/min. Gas chromatography–mass spectrometry (GC–MS) characterization revealed that the liquid product consisted predominantly of complex mixtures, with C6 compounds dominating the carbon number distribution, followed by C8 and C5 compounds. During the pyrolysis process, CO₂ and CO were the main components of the non-condensable gases, whereas total hydrocarbons (THC) were generated at pyrolysis temperatures of 500 °C and above. The carbon content of biochar increased as the pyrolysis temperature increased, while the oxygen and hydrogen contents decreased. These findings elucidate the influence of temperature and heating rate on the chemical properties of pyrolysis products derived from RH. In addition, the kinetic analysis of RH pyrolysis showed that the estimated activation energy varies depending on the applied method. Therefore, the combined use of multiple methods is considered desirable for providing a more reliable kinetic interpretation of RH pyrolysis.