Biomass Group, Nanjing Agricultural University, PO Box 68, 40 Dianjiangtai Road, Nanjing 210031

Realizing the Co-valorization of Waste Cooking Oil into High-quality Biofuel and Carbon Nanotube Precursor via Catalytic Pyrolysis Process

Recently, Master student Mr. Guo-qiang Zhu supervised by Associate Prof. Lu-jiang Xu published a research article in Chemical Engineering Journal about realizing the co-valorization of waste cooking oil into high-quality biofuel and carbon nanotube precursor via catalytic pyrolysis process.

Valorizing renewable precursors into high-quality biofuel and functional carbon nanomaterials can considerably improve the economic viability. Here, we propose a process for integrated production of high-quality biofuel and carbon nanotubes from waste cooking oil via catalytic pyrolysis coupling with CVD technology. The natural biochar catalyst demonstrates excellent deoxygenation performance and good stability in catalytic pyrolysis process. The AAEMs content in biochar catalysts from various sources has a strong correlation with the selectivity of esters and hydrocarbons in bio-oil. The biofuel obtained under optimal conditions exhibited potential as a precursor for jet fuel. The combined CVD process successfully convert pyrolysis gas into multi-wall carbon nanotubes with yield of 2.13%. The technical-economic analysis demonstrated the feasibility of the integrated production process, projecting profitability and substantial total profit over a ten-year period. Overall, this study improves the economic viability of the waste cooking oil pyrolysis process and can support its wider commercial application.

Related results were published in Chemical Engineering Journal：

GQ Zhu, MX Zhu, EZ Wang, CX Gong, YR Wang, WJ Guo, GL Xie, W Chen, C He, LJ Xu*, H Li, Y Zhang, Zhen Fang, Natural Biochar Catalyst: Realizing the Co-Valorization of Waste Cooking Oil into High-Quality Biofuel and Carbon Nanotube Precursor via Catalytic Pyrolysis Process, Chemical Engineering Journal (IF 16.7), 486 (2024), 150195. https://doi.org/10.1016/j.cej.2024.150195.

Co-valorization of waste cooking oil into high-quality biofuel and carbon nanotube precursor via catalytic pyrolysis process催化热解工艺实现餐厨废油共价制备优质生物燃料和碳纳米管前驱体

催化热解工艺实现废食用油转化为优质生物燃料和碳纳米管前驱体

最近，硕士生祝国强在徐禄江副教授的指导下，在国际学术期刊Chemical Engineering Journal (Q1, IF=15.1) 发表了一篇关于原生生物炭热解催化废弃油脂联产高品质液体燃料和碳纳米管前驱体的研究性论文。

以废弃油脂为原料联产高品质液体燃料和功能性碳纳米材料可显著提高经济可行性。因此，本文提出了一种利用秸秆基生物炭催化热解耦合气相沉积技术联产生产高质量生物燃料和碳纳米管工艺。原生生物炭在催化热解过程中表现出优异的脱氧性能和良好的稳定性。不同来源的生物炭催化剂中碱金属含量与热解油中酯类和烃类的选择性呈一阶线性相关。在最佳条件下获得的生物燃料表现出作为航空燃料前体的潜力。气相沉积技术成功实现将热解气转化为多壁碳纳米管，收率为2.13%。技术经济评价证明了联产的可行性，并预测了10年期间的盈利能力。本研究提高了废弃油脂热解工艺的经济可行性，为其更广泛的商业应用提供了参考。

结果发表在Chemical Engineering Journal：

GQ Zhu, MX Zhu, EZ Wang, CX Gong, YR Wang, WJ Guo, GL Xie, W Chen, C He, LJ Xu*, H Li, Y Zhang, Zhen Fang, Natural Biochar Catalyst: Realizing the Co-Valorization of Waste Cooking Oil into High-Quality Biofuel and Carbon Nanotube Precursor via Catalytic Pyrolysis Process, Chemical Engineering Journal (IF 16.7), 486 (2024), 150195. https://doi.org/10.1016/j.cej.2024.150195.

Valorization of Waste PET: Understanding the Role of Active Ammonia in Facilitating PET Depolymerization and Aromatic Nitrile Formation

Recently, Mr Geliang Xie supervised by assoc. Prof. Lujiang Xu published a research article in Journal of Cleaner Production about preparation of aromatic nitrile by pyrolysis of polyester plastic PET under active ammonia atmosphere.

Realizing the recovery and valorization of waste polyethylene terephthalate (PET) plastics into value-added products have gained significant importance. This study successfully synthesized aromatic nitriles, specifically terephthalonitrile (TPN), from waste polyethylene terephthalate (PET) plastic through in situ catalytic pyrolysis with urea and γ-Al₂O₃ catalyst. Based on distributed activation energy model, positive interaction between waste PET and urea is responsible for improved thermal decomposition kinetics. The dosage of urea and pyrolysis temperature significantly influenced TPN production. TPN yield reached 32.5% with selectivity of 85% at 550°C and equivalent urea dosage. Density functional theory calculations validated the role of active ammonia in reducing energy barriers and thus facilitating PET depolymerization. The study highlights the feasibility of recycling waste PET into valuable aromatic nitriles through in situ catalytic pyrolysis with urea and enhances the understanding of the pyrolysis process.

Publication:

GL Xie, GQ Zhu, YF Kang, MX Zhu, QQ Lu, C He, LJ Xu*, Zhen Fang, Valorization of Waste PET: Understanding the Role of Active Ammonia in Facilitating PET Depolymerization and Aromatic Nitrile Formation. Journal of Cleaner Production (IF 11.1), 434 (2024), 140204. https://doi.org/10.1016/j.jclepro.2023.140204.

With urea as the ammonia source and γ-Al₂O₃ as the catalyst, terephthalonitrile (TPA) can be synthesized by catalytic co-pyrolysis of PET. Co-pyrolysis reduces the activation energy by 50%. The yield and selectivity of TPN under optimal conditions were 32.53% and 85%, respectively.Density functional theory (DFT) calculations revealed the possible mechanism of PET formation of TPN in the presence of urea and γ-Al₂O₃.

以尿素为氨源，PET在γ-Al₂O₃催化剂下进行催化共热解可以合成对苯二甲腈（TPA）。共热解可使活化能降低50%，最佳条件下TPN的收率和选择性分别为32.53%和85%。密度泛函理论（DFT）计算揭示了在尿素和γ-Al₂O₃存在下PET形成TPN的可能机理。

硕士生谢葛亮在徐禄江副教授指导下，在国际学术期刊Journal of Cleaner Production上发表研究性论文：

废PET的增值:了解活性氨在促进PET解聚和芳腈生成中的作用

最近，硕士生谢葛亮在徐禄江副教授指导下，在国际学术期刊Journal of Cleaner Production (Q1; Impact factor: 11.1)上发表了一篇关于活性氨氛围下热解聚酯塑料PET制备芳香腈的研究性论文。

实现废旧聚对苯二甲酸乙二醇酯(PET)塑料的回收和增值为增值产品具有重要意义。以聚对苯二甲酸乙二醇酯(PET)废塑料为原料，在尿素和γ-Al₂O₃催化剂的催化下原位热解合成了芳香族腈，特别是对苯二甲酸乙二醇酯(PET)。基于分布活化能模型，废pet与尿素的正相互作用是改善热分解动力学的原因。尿素用量和热解温度对TPN产量有显著影响。在550℃、同等尿素用量条件下，TPN收率为32.5%，选择性为85%。密度泛函理论计算验证了活性氨在降低能垒从而促进PET解聚中的作用。该研究突出了利用尿素原位催化热解将废PET回收为有价芳香烃的可行性，并加深了对热解过程的认识。

详情可见：

GL Xie, GQ Zhu, YF Kang, MX Zhu, QQ Lu, C He, LJ Xu*, Zhen Fang, Valorization of Waste PET: Understanding the Role of Active Ammonia in Facilitating PET Depolymerization and Aromatic Nitrile Formation. Journal of Cleaner Production (IF 11.1), 434 (2024), 140204. https://doi.org/10.1016/j.jclepro.2023.140204.