Cellulose acetate (CA) is a biodegradable polymer widely used in medical, environmental, and industrial applications due to its favorable physicochemical properties such as solubility, polarity, and film-forming ability. However, its disposal remains a significant challenge, particularly because conventional recycling requires deacetylation—a process that generates substantial wastewater. This study presents a sustainable and environmentally friendly approach to directly convert CA waste into syngas (H₂ and CO) via catalytic pyrolysis using CO₂ as a reactive co-feedstock and Ni/SiO₂ catalysts. The integration of CO₂ not only enhances syngas yield but also mitigates coke formation on the catalyst surface, offering dual technical and environmental advantages.
The pyrolysis of CA was conducted under both nitrogen (N₂) and CO₂ atmospheres to evaluate the role of CO₂ in valorizing CA. In the absence of catalysts, the primary volatile products were acetic acid and methyl acetate, which further thermally cracked into syngas and methane. However, the syngas yield remained low under N₂. To overcome this limitation, two-stage pyrolysis was employed, increasing thermal energy input through an additional heating zone at 600 °C. This method resulted in a fourfold increase in syngas production compared to single-stage pyrolysis. Further enhancement was achieved by introducing Ni-based catalysts. With 5 wt% Ni/SiO₂, syngas production increased by over two orders of magnitude, demonstrating the critical role of catalysis in promoting gasification reactions.
Notably, CO₂ significantly amplified the formation of carbon monoxide (CO), especially in the presence of Ni catalysts. This enhancement is attributed to gas-phase reactions between CO₂ and volatile pyrolysates (VPs) evolved from CA, such as acetic acid and methyl acetate. These reactions—particularly the reverse Boudouard reaction and dry reforming—are catalytically accelerated by Ni, leading to efficient CO generation.12112-67-3 Formula Moreover, CO₂ acts as a mild oxidant, suppressing carbon deposition on the catalyst surface, thereby improving catalyst stability and longevity. This effect was confirmed through X-ray diffraction (XRD) and temperature-programmed oxidation (TPO) analyses, which revealed lower coke accumulation when CO₂ was used instead of N₂.
The compositional matrix of pyrolytic oil further supported these findings: acetic acid content decreased substantially under CO₂ and catalytic conditions, indicating reallocation of carbon toward gaseous products. Mass balance analysis confirmed that a larger fraction of carbon was converted into syngas rather than char or liquid residues.OPG Antibody web Additionally, higher reaction temperatures (700 °C) and increased Ni loading led to even greater syngas yields, confirming the positive correlation between catalyst activity and operational parameters.PMID:35038119
In conclusion, this work establishes a robust, scalable platform for transforming CA waste into high-value syngas through CO₂-assisted catalytic pyrolysis. The synergistic combination of CO₂ and Ni/SiO₂ catalysts enables efficient conversion, reduces environmental impact, and offers potential for integration into circular economy systems. Future research should focus on optimizing reactor design, catalyst regeneration, and process scalability to enable industrial application.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com