One-Step Carbothermal Reduction Synthesis of Metal-Loaded Biochar Catalyst for In Situ Catalytic Upgrading of Plastic Pyrolysis Products

Abstract

A novel biochar-supported metal catalyst was prepared in this study using a one-step carbothermal reduction synthesis method for the catalytic pyrolysis of plastics. Several catalysts with different metals (Cu, Fe, Ni, and Ru) loaded on three biochar supports from lignin, soybean straw, and Chlorella vulgaris were evaluated using XRD, FTIR, NH 3 -TPR, and TEM. Zerovalent metal nanoparticles, including Ni, Cu, and Ru, and various functional groups were observed on the biochar surface. The chemical selectivities of gasoline hydrocarbons (C 4 −C 12 hydrocarbons) reached 76.2% with a remarkable catalytic cracking effect of Ni/lignin biochar on low density polyethylene (LDPE). Catalytic performance was comparable to that of the Ru-based catalyst, which contributed to 85.6% of gasoline hydrocarbons. The Ni/lignin catalytic cracking of plastic waste simulated by LDPE, polypropylene (PP), and polystyrene (PS) showed a maximum selectivity of 87.9% for C 4 −C 12 hydrocarbons and yields of 78.1 mg/ g for benzene, toluene, and xylene (BTX). The mechanism related to the cleavage of long chain radicals of polyethylene, polypropylene, and polystyrene as well as the aromatization of aliphatics were proposed.

Thermochemical Valorization of Waste Plastic for Production of Synthetic Fuels, Fine Chemicals, and Carbon Nanotubes

“…For BTX production, there is a correlation of BTX yield with the amount of PS in the feedstock. Noteworthily, the highest BTX yield can be obtained when 50% of the mixed plastics is PS. , Luong et al explored the synergistic interaction using a simple model of mixing PS and LDPE at different ratios, using H-ZSM-5 as the catalyst. Both aromatics and BTX yields remain high when PS is ≥50% in the feedstock.…”

Synergy between Cu and Lewis Acidic Sites in Cu/Zn-FeOx Catalysts for the Selective Conversion of Poly(ethylene terephthalate) Waste to p-Xylene and Ethylene Glycol

“…70 million tons, accounting for 12% of worldwide solid plastic waste. , Handling methods of PET typically include landfill and thermochemical processes. , Landfill occupies land, and the low degradation rate of PET in the natural environment means a persistent potential hazard to underground water . Thermochemical processes, including gasification, pyrolysis, , hydrolysis, and hydrogenolysis, could recover or partially recover the energy or chemical potential of PET by converting it into hydrogen, liquid fuels, terephthalic acid (TPA), ethylene glycol (EG), and arenes. , Hydrogenolysis could convert PET waste into arenes and EG via breaking ester bonds . The produced arenes could be further used for the synthesis of aromatic-rich plastics .…”

“…3,4 Landfill occupies land, and the low degradation rate of PET in the natural environment means a persistent potential hazard to underground water. 5 Thermochemical processes, including gasification, 6 pyrolysis, 7,8 hydrolysis, 9 and hydrogenolysis, 10 could recover or partially recover the energy or chemical potential of PET by converting it into hydrogen, liquid fuels, terephthalic acid (TPA), ethylene glycol (EG), and arenes. 11,12 Hydrogenolysis could convert PET waste into arenes and EG via breaking ester bonds.…”

Aromatic‐rich oil production from catalytic co‐pyrolysis of pine sawdust and LDPE with bifunctional biochar by different preparation methods

“…The selectivity of C 4 -C 12 hydrocarbons was 87.9% for BC with Ni-loaded, and the selectivity of monocyclic aromatic hydrocarbons was 72.4%. 15 Most activated BCs in previous studies have only been used to catalyze biomass or plastics alone, and research on co-pyrolysis has been concentrated primarily on optimizing co-pyrolysis reaction parameters. However, there has been little reporting on the synergistic effect of O-containing groups and metal-active sites on co-pyrolysis during the fast pyrolysis of BC with ZnCl 2 .…”