High-Value Utilization of Amaranth Residue and Waste LDPE by Co-Pyrolysis

Area of Science:

• Waste Management
• Biomass Conversion
• Polymer Recycling

Background:

• Amaranth (A. cruentus) processing generates significant waste, impacting the agro-industrial sector.
• Waste valorization through co-pyrolysis offers a sustainable solution for managing agricultural and plastic waste.

Purpose of the Study:

• To investigate the co-pyrolysis of Amaranthus cruentus (AC) residues and low-density polyethylene (LDPE).
• To analyze the thermochemical conversion process and characterize the resulting pyrolysis products (liquid and biochar).

Main Methods:

• Co-pyrolysis experiments were conducted using a thermogravimetric analyzer.
• Thermogravimetry-Fourier infrared spectroscopy-gas chromatography-mass spectrometry (TG-FTIR-GC MS) was employed for detailed analysis.
• Kinetic parameters were determined using Ozawa-Flynn-Wall (OFW) and Kissinger-Akahira-Sunose (KAS) methods.

Main Results:

• The average activation energy for AC/LDPE pyrolysis was calculated using OFW and KAS methods.
• Pyrolysis liquid from AC contained 38.14% hydrocarbons, primarily aliphatic.
• Hydrocarbons were identified in the resinous and waxy fractions of the AC/LDPE pyrolysis liquid.

Conclusions:

• Co-pyrolysis of AC residues and LDPE effectively produces hydrocarbon-rich pyrolysis liquids.
• The biochar derived from both AC and the AC/LDPE mixture exhibits similar properties and agricultural applicability.
• This study highlights a viable method for waste recycling and the creation of value-added products.