RESOURCES CONSERVATION AND RECYCLING
·
2024
·
IF 11.2
Wei-Zhen Zheng,Xiao Li,Peng-Yuan Xu,Ze-Yang Zhang,Ping-Li Wang,Bo Lu,Dan Huang,Zhi-Chao Zhen,Jun-Hui Ji,Ge-Xia Wang
The recycling of poly(butylene succinate) (PBS) plastic aligns with the principles of sustainable development and the circular economy. However, existing recycling systems often lack environmental friendliness and involve complex product separation operations. In this study, we developed a new recycling system based on succinic acid, a constituent monomer of PBS, as the catalyst and water as the solvent to hydrolyze PBS into different products, including oligomers, monomers, and tetrahydrofuran. These products (monomers or oligomers) were then repolymerized without requiring any separation steps by adding tetrabutyl titanate as the catalyst and 1,4-butanediol. The resynthesized PBS had similar mechanical and thermal properties to those synthesized from commercial monomers. In addition, the selective hydrolysis of PBS in mixed plastics was achieved by adjusting the reaction conditions. The process demonstrated here could inspire new recycling strategies for plastic wastes.
研究领域:
材料科学
·
可持续发展
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Sustainable Energy & Fuels
·
2020
·Vol. 4
·期 11
·5588-5594
·
IF 5.503
Shi Qiu,Meng Wang,Yunming Fang,Tianwei Tan
Reductive catalytic fractionation (RCF) is a promising lignin-first biorefinery strategy that yields a deeply depolymerized lignin and nearly theoretical amounts of lignin monomers with reductive catalysts. Theoretically, the immediate stabilization with a catalyst is a key step in the RCF process, but the experimental support is lacking and few researchers have investigated the timeliness of stabilization. In this study, an on-line catalyst addition device was used to realize the flexible addition of a catalyst at different times in a high-pressure batch reactor. It was found that immediate stabilization is definitely indispensable for high lignin monomer yield, and the timeliness of stabilization mainly depends on the occurrence of repolymerization. Fast repolymerization occured at temperatures from 200 °C to 250 °C and more seriously around 250 °C, suggesting that the RCF process can be realized as long as adding the catalyst occurs before the temperature reaches 200 °C. Further this proves the feasibility of splitting delignification and stabilization/hydrogenation processes, and explains the reason for the reaction temperatures used in effective semi-continuous RCF processes at lower than 200 °C.
研究领域:
生物化学
·
可再生资源工程
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2024
·
IF 3.5
Nan Wang,Yi Li,Xiujie Cheng,Ruiqi Zhang,Qing Zhou,Jiayu Xin,Dongxia Yan,Junli Xu,Xingmei Lu
This study employed titanium catalysts to degrade low-quality PET (polyethylene terephthalate) bottle flakes and subsequently re-polymerized the degradation solution to investigate whether the titanium catalyst could restore the physical and chemical properties of the degraded PET bottle flakes. The reaction process of property restoration was characterized using GPC, DSC, ICP, NMR, and so forth. The mechanism of titanium catalyst-catalyzed PET polymerization was explored through simulation calculations. The results indicate that the waste PET bottle flakes have been restored to the standard of first-grade PET bottle flakes under the degradation and re-polymerization processes with the aid of dibutyl ethylene glycol titanate catalysts. The Ti ion in the recycled PET is stable and the metal ion leached from the restored PET in the strong acid environment meets food-grade safety requirements. This study is expected to provide a new way for recycling waste PET bottle flakes.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2020
·Vol. 10
·期 4
·402
·
IF 3.52
Depeng Han,Wang Yin,Ali Arslan,Tongrui Liu,Yan Zheng,Shuqian Xia
Repolymerization is a huge problem in the storage and processing of biomass pyrolysis liquid (PL). Herein, to solve the problem of repolymerization, mild catalytic hydrotreatment of PL was conducted to convert unstable PL model compounds (hydroxyacetone, furfural, and phenol) into stable alcohols. An Ni/SiO2catalyst was synthesized by the deposition-precipitation method and used in a mild hydrotreatment process. The mild hydrotreatment of the single model compound was studied to determine the reaction pathways, which provided guidance for improving the selectivity of stable intermediate alcohols through the control of reaction conditions. More importantly, the mild hydrotreatment of mixed model compounds was evaluated to simulate the PL more factually. In addition, the effect of the interaction between hydroxyacetone, furfural, and phenol during the catalytic hydrotreatment was also explored. There was a strange phenomenon observed in that phenol was not converted in the initial stage of the hydrotreatment of mixed model compounds. Thermogravimetric analysis (TGA), Ultraviolet-Raman (UV-Raman), and Brunauer−Emmett−Teller (BET) characterization of catalysts used in the hydrotreatment of single and mixed model compounds demonstrated that this phenomenon did not mainly arise from the irreversible deactivation of catalysts caused by carbon deposition, but the competitive adsorption among hydroxyacetone, furfural, and phenol during the mild hydrotreatment of mixed model compounds.Keywords:repolymerization;biomass pyrolysis liquid;mild catalytic hydrotreatment;mixed model compounds;competitive adsorption
研究领域:
能源与燃料化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）