Natural and Calcined Clinoptilolite as Catalyst for Co-pyrolysis of Sargassum and HDPE: Characterization and Application of Byproducts

• Published in: Topics in catalysis Vol. 68; no. 14; pp. 1791 - 1804
• Main Authors: Sanabria Pérez, Francisco Javier, Solis Maldonado, Carolina, Luna Sánchez, Raúl Alejandro, Ortíz Silos, Nayeli, Cristóbal-Salas, Alfredo, Sandoval-Rangel, Ladislao, Rivera de la Rosa, Javier, Dimas-Rivera, Gloria Lourdes, Atehortua Garcés, Lucía
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2025; Springer Nature B.V
• Subjects: Aliphatic hydrocarbons; Ammonia; Biofuels; Byproducts; Catalysis; Catalysts; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Decarboxylation; Dehydration; Fourier transforms; Gas chromatography; High density polyethylenes; Hydrocarbons; Industrial Chemistry/Chemical Engineering; Mass spectrometry; Original Paper; Pharmacy; Physical Chemistry; Pore size distribution; Pyrolysis; Roasting; Soil properties; Soil remediation; Sulfur; HDPE; Clinoptilolite; Byproducts; Calcination; Co-pyrolysis; Sargassum
• ISSN: 1022-5528; 1572-9028
• DOI: 10.1007/s11244-025-02070-7

The objective was to evaluate the non-modified (CN) and calcined (CC) clinoptilolite as catalysts of the in-situ co-pyrolysis of Sargassum biomass and high-density polyethylene (HDPE). Both CN and CC were utilized to enhance the pyrolysis reactions, aiming to upgrade the quality of the resulting byproducts. The potential applications of these byproducts for soil remediation, biofuel and pharmaceutical purposes were also discussed. The feedstock materials and byproducts were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), temperature-programmed desorption of ammonia (TPD-NH 3 ), and gas chromatography coupled to mass spectrometry (GC–MS). Calcination of CN at 550 °C for 5 h resulted in a 74% reduction in the number of acid sites, a 40% decrease in crystallinity, and a 1.2-fold reduction in surface area, while the Si/Al ratio and pore size distribution remained largely unchanged. The incorporation of HDPE and catalysts increased the conversion rate of Sargassum from 59% to 73%, facilitated by decarboxylation, dehydration, and secondary cracking reactions. Concerning the oil byproduct, the CN catalyst improved its composition by increasing the yield of aliphatic hydrocarbons to 41.8% and reducing sulfur and oxygenated compounds. Conversely, the CC catalyst enhanced the gas byproduct by promoting the production of light hydrocarbons compounds (1.7 mol/kg) and methane (1.5 mol/kg). The resulting solid residual byproduct (biochar) from all tests exhibited sulfur and nitrogen content, and adsorption properties suitable for agricultural soil remediation. Utilizing cost-effective natural catalysts in the co-pyrolysis of Sargassum and HDPE optimizes the recovery of two marine wastes that pose ecological risks in the Caribbean.