ENERGY CONVERSION AND MANAGEMENT
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2024
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IF 9.9
Yang Zhang,Jun Zhao,Lei Zhang,Yong Chen,Wangjing Ma
The recycling and processing of plastic waste to promote resource sustainability has emerged as a global concern. Selectivily upcycling polyolefins into valuable monocyclic aromatic hydrocarbons (MAHs) is a promising strategy to promote a circular economy but limited by low yield and selectivity. In this study, one-step microwave-triggered tandem pyrolysis coupling ZSM-5 catalytic reforming technology was explored, which is efficient for selectively transforming plastic into benzene, toluene, ethylbenzene, and xylene (BTEX) riched oil products. Pyrolysis and catalytic processes were achieved by mixing plastic and ZSM-5 with graphite, respectively, and placing them in the bottom and top layers of the reactor. Results indicate the mass ratio of plastic or ZSM-5 to graphite and microwave irradiation power would influence the selectivity and yield of MAHs. After careful investigation, the optimum reaction conditions are deemed to be 600 W, and the mass ratio of LDPE and ZSM-5 to graphite is 3:1 and 1:1, respectively, and delightful selectivity and yield of MAHs of 82.06% and 28.12 wt% are obtained under the above conditions. More importantly, the BTEX accounted for a significant amount in the MAHs with the selectivity and yield of 70.53% and 24.17 wt%, demonstrating a strong ability to produce high-value BTEX, which is attributed to the ZSM-5 providing a sufficient active site for reforming the pyrolysis vapors and promote the formation of BTEX by cracking, aromatization and Diels-Alder reactions. Additionally, gas products are rich in C 2 H 4 , C 3 H 6 and C 4 H 8 olefin monomers accounting for around 60% of the gas products, which also manifest high value. Besides, the ZSM-5 can be stabilized by exceeding three successive cycles, and this strategy is also suitable for the catalytic upcycling of PP and mixed plastics to produce MAHs selectively. Therefore, this one-step microwave-triggered tandem pyrolysis coupling ZSM-5 catalytic reforming technology provides a potential waste resource utilization method to convert plastic waste into high-value petrochemical products.
研究领域:
化学工程
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环境科学
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材料科学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2024
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IF 8.1
Jun Zhu,Jun Chen,Jianan Chen,Jicheng Zhou,Wentao Xu
Direct decomposition of H 2 S into H 2 and S is an attractive alternative to the Claus process, because CO x -free H 2 and S can be simultaneously recovered from an abundant and toxic waste gas, which has huge social economic and ecological environmental benefits. However, it is still a great challenge to achieve the direct H 2 S decomposition reaction with high efficiency due to the thermal equilibrium limitation. Herein, a core-shell structured Mo x C@ZrO 2 was developed as novel microwave catalyst for microwave catalytic H 2 S decomposition. More specifically, the H 2 S conversion over Mo x C@ZrO 2 catalyst is as high as 99.9% at 650 °C, which immensely surpasses the H 2 S equilibrium conversion (6.1% at 650 °C). This study provides an effective strategy for the design of highly active microwave catalysts, and supplies a strategy for efficiently catalytic decomposition of H 2 S waste and recovering high-value hydrogen and sulfur at lower reaction temperatures.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
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2021
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IF 7.033
Jianan Chen,Jun Zhu,Wentao Xu,Yi Chen,Jicheng Zhou
Highly efficient H 2 and S production from copious waste H 2 S is beneficial from both environmental and energy. Whereas, the highly effective direct decomposition of H 2 S reaction faces a gigantic obstacle, that is, there is the severe thermal equilibrium limitation. Herein, a family of TiO 2 modified Mo x C as novel microwave catalysts have been developed. This work demonstrates that Mo 2 C, Mo 2 C-TiO 2 and MoC@TiO 2 microwave catalysts display excellent catalytic performance to recover both valuable H 2 and elemental S from the direct decomposition of H 2 S under microwave irradiation . The optimal H 2 S conversion of MoC@TiO 2 can be as high as 99.9% (almost complete conversion) at 700 °C, which greatly outpaces the corresponding H 2 S equilibrium conversion under microwave irradiation . This result of the chemical equilibrium limitation being broken shows an interesting phenomenon, namely a significant microwave selective catalytic effect by microwave catalysis in H 2 S decomposition reaction . In addition, the apparent activation energy of the Mo 2 C, Mo 2 C-TiO 2 and MoC@TiO 2 microwave catalysts reduced to 18.2 kJ/mol, 16.8 kJ/mol and 15.6 kJ/mol under microwave irradiation. The work supplies a strategy for highly effective valuable H 2 and S production from H 2 S decomposition reaction , and paves a path to high-value utilization of hazardous waste H 2 S resources with energy-saving heating method.
研究领域:
化学工程
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环境科学
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能源科学
✓ 已验证
DOI
高影响因子
ENERGY
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2024
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IF 9
Yuechi Che,Xiaopeng Jia,Yongjie Hu,Jian Li,Zhi Wang,Beibei Yan,Guanyi Chen
Tar catalytic removal is a key issue in biomass gasification , which is suffering from catalyst coking and sintering. Microwave technology is attractive due to the high activity on polar molecules and ability to lower activation energy . In this study, the Co/C derived from metal-organic frameworks (ZIF-67) was developed as a bifunctional microwave catalyst that can strengthen the interaction between microwave and tar catalytic reforming , and enhance the anti-coking and sintering ability. The effects of the temperature, heating method, tar concentration, and catalyst support on model tar conversion rate were investigated. The operating conditions at 700 °C and tar concentration lower than 20 g/m 3 can reach a promising conversion rate over 90.15 % under microwave irradiation . On the one hand, microwave heating groups performed better in conversion rate and coking compared to conventional heating, due to the active species generated from the microwave plasma . On the other hand, Co/C showed better performance in catalytic activity and sintering stability, due to the highly dispersion of cobalt nanoparticles and the confinement effect of carbon nanotubes on the catalyst surface . These findings proposed a novel approach for efficient biomass tar removal under microwave irradiation, and offered a potential tool to further reveal the mechanism in microwave driven tar steam reforming system.
研究领域:
能源与环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2025
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IF 21.1
Jinglin Li,Jingwen Chang,Endian Hu,Kailun Chen,Li Lin,Yuchen Gao,Yukun Zhao,Weikai Qin,Jianguo Jiang
Plastic pollution presents severe environmental challenges, necessitating sustainable waste-management system. This study investigated hydrogen conversion from various plastic mixtures—polystyrene (PS), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and polyethylene terephthalate (PET)—via microwave thermal processing with a Ni-Al-Fe catalyst. Hydrocarbon plastics (PP/PE/PS) yielded 49.17 mmol/g hydrogen with ∼90 vol% purity, comparable to that of linear plastic, demonstrating negligent effects of aromatic structure on hydrogen yields. PET addition significantly reduced hydrogen due to oxygenated-intermediates inhibition effects active sites and oxidation of aluminum. Similarly, PVC decreased yields as chlorine induced metal migration and catalyst surface damage. Cycle-generated carbon nanotubes (CNTs) from plastic mixtures were used to mitigate the unfavorable effects. The modified catalyst (Ni-Al-Fe-CNTs) achieved 35 % higher hydrogen yields for both oxygen- and chlorine- containing plastics mixtures. This is attributed to enhanced surface strain, electrical structures, and adsorption of intermediates from CNTs, preserving coordination environment and enabling partial Ni and Fe reduction to form heterojunctions and oxygen vacancies. This study developed a circular economy model for managing plastic waste and high-value energy conversion.
研究领域:
环境科学
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能源工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Jun Zhao,Jianye Gao,Duanda Wang,Yong Chen,Lei Zhang,Wangjing Ma,Sui Zhao
The value-added utilization of plastic waste is a powerful way to effectively manage plastic waste and achieve a circular economy. However, high-performance catalysis often requires suitable substrate catalysts or complex processes, while low-energy consumption plastic upcycling technology is also urgently needed. In this study, various cheap and self-dispersing highly active iron-cobalt–nickel-monometallic and bimetallic functional catalysts were synthesized through a simple and fast one-step method for catalytic upcycling of plastic into hydrogen and carbon nanotubes . Results indicated that Ni 1 Fe 3 O x , Ni 1 Co 3 O x and Ni 3 Co 2 O x are the most efficient catalysts, realizing hydrogen yield as high as 60.2 mmol g-1 plastic, 63.2 mmol g-1 plastic, 63.5 mmol g-1 plastic and high selectivity of 79.4 vol%, 81.4 vol% and 83.7 vol%, respectively, for microwave-intensified catalytic dehydrogenation of LDPE, the hydrogen yield of which is almost 2–3 times that of traditional thermal catalysis. More importantly, a high hydrogen yield of 44.1 mmol g-1 plastic is also achieved when the feedstock is extended to the landfill mixed plastics waste. These results demonstrate that the synergies of self-dispersing bimetallic catalysts are promising for plastic waste upcycled via microwave-intensified catalysis.
研究领域:
化学工程
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Yin Wang,Ruotong Wang,Lan Yu,Yun Wang,Chuanhui Zhang,Xiaodong Zhang
A series of new layered composite catalysts LaCu 0.5 Co 0.5 O 3 -MMT 0.2 /CN x (x = 0.025, 0.075, 0.125) were prepared by montmorillonite (MMT) and g-C 3 N 4 (CN) in situ intercalation of B-site double perovskite. The experimental results showed that the appropriate MMT and CN loading of LaCu 0.5 Co 0.5 O 3 -MMT 0.2 /CN 0.075 were beneficial to the increase of catalytic performance because perovskites were evenly distributed between the layers of MMT and CN and effectively avoided the loss of active components. The sample had a smaller particle size distribution, a larger specific surface, a higher ratio of O ads /O latt and excellent microwave absorption capabilities. The removal rate reached 98.7% in 6 min under optimal conditions with catalyst dosage of 9.5 g/L, H 2 O 2 dosage of 350 μL, pH of 4, MW power of 500 W, and bisphenol A (BPA) concentration of 50 mg/L. LCCOM 0.2 /CN 0.075 also showed good reusability with a degradation efficiency of 95.7% even after the 5th cycle. And the microwave-catalyzed degradation followed pseudo first-order kinetics. Combining relevant characterization and experimental results of free radical capture, possible reaction mechanisms were discussed. The surface active sites of the catalyst can be excited by microwaves to produce oxidized free radicals, thereby degrading bisphenol A through electron-hole transport.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2024
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IF 10.8
Jinglin Li,Kailun Chen,Li Lin,Siyu Han,Fanzhi Meng,Endian Hu,Weikai Qin,Yuchen Gao,Jianguo Jiang
The escalating levels of plastic waste and energy crises underscore the urgent need for effective waste-to-energy strategies. This study focused on converting polypropylene wastes into high-value products employing various iron-based catalysts and microwave radiative thermal processing. The Al–Fe catalysts exhibited exceptional performance, achieving a hydrogen utilization efficiency of 97.65% and a yield of 44.07 mmol/g PP. The gas yields increased from 19.99 to 94.21 wt % compared to noncatalytic experiments. Furthermore, this catalytic system produced high-value bamboo-shaped carbon nanotubes that were absent in other catalysts. The mechanism analysis on catalytic properties and product yields highlighted the significance of oxygen vacancies in selecting high-value products through two adsorption pathways. Moreover, the investigation examined the variations in product distribution mechanisms between conventional and microwave pyrolysis, in which microwave conditions resulted in 4 times higher hydrogen yields. The technoeconomic assessment and Monte Carlo risk analysis further compared the disparity. The microwave technique had a remarkable internal rate of return (IRR) of 39%, leading to an income of $577/t of plastic with a short payback period of 2.5 years. This research offered sustainable solutions for the plastic crisis, validating the potential applicability of commercializing the research outcomes in real-world scenarios.
研究领域:
环境科学
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能源工程
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Yan Wang,Kangqi Cao,Wenlong Sun,Xiangxi Lin,Jianwei Wang,Jessica Villarreal,Longzhi Li
Microwave catalytic pyrolysis of lignin is one of emerging technologies for efficiently converting lignin into fuels and chemicals. Molecular sieves (HZSM-5) are widely used as carriers to load metallic components for biomass pyrolysis but often encounter challenges such as high diffusion resistance and insufficient acidity of acidic sites. Traditionally, HZSM-5 is directly modified to enhance the activity of the acidic sites, but this modification is ineffective in improving the metallic components’ activity. Instead, we made nitrogen doping on Fe and then supported on HZSM-5 to construct Fe-N 25 /HZSM-5 catalysts for microwave catalytic pyrolysis of lignin. The N-doped Fe has the effect of “killing two birds with one stone” on enhancing the catalytic activity. The characterization results indicated that N replaced C of the graphitic carbon network to form carbon nitride structure, and further combined with Fe to generate Fe-N bonds, improving the electronegativity of the metallic component. Besides, the loading of N-doped Fe increased the acidity of the catalyst. The utilization of 1.00Fe-N 25 /HZSM-5 obtained the greatest bio-gas yield (35.2 wt%), a hydrogen yield of 27.8 mL/min, bio-oil yield (36.4 wt%) and phenol selectivity of 46.2 %. The likely pathway of microwave catalytic pyrolysis on Fe-N 25 /HZSM-5 was proposed through DFT calculation, using guaiacol as a model compound. The results suggested that N-doped Fe on HZSM-5 8 T tended to break the side-chain methoxy during pyrolysis of guaiacol, with energy barrier of 0.14 eV. This paper provides a promising strategy for modification of microwave pyrolysis catalysts.
研究领域:
能源化学
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
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IF 12.2
Yuxin Liu,Qintie Lin,Jieyi Pan,Yirong Deng,Junli Zheng,Mingchao Lyu,Hao Luo,Yang Luo
The existing remediation technologies for Cr(VI) contamination soil suffer from long processing times. Microwave catalysis is an efficient environmental remediation technology, and the reasonable design of microwave catalysts can enable a microwave catalytic system to rapidly complete the remediation of Cr(VI). In this study, a microwave catalyst, NRFC-3, with high microwave absorption performance and electron density was designed via a nitrogen enrichment strategy. Density functional theory (DFT) calculations verified that the electron density of the material was increased by nitrogen-enriched strategy. Under the experimental conditions, the electrons (e − ) of NRFC-3 originate from “hot spots” and the current density is not lower than 3.78 × 10 9 e·g −1 ·s −1 . In addition, the reduction of Cr(VI) in the MW/NRFC-3 system is feasible through DFT predictions, and this conclusion was experimentally verified. The MW/NRFC-3 system has a remediation efficiency of 100 % for Cr(VI)-contaminated soil within 25 min, significantly reduced the toxicity of Cr(VI) to the environment and humans, and had long-term stability. The potential application of the MW/NRFC-3 system was verified by remediation experiments on Cr(VI)-contaminated soils of different degrees. This study provides a new technology for the rapid and harmless treatment of Cr(VI)-contaminated soil.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2022
·Vol. 152
·期 12
·3795-3806
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IF 2.936
Tao Wanyi,Bo Longli,Li Mingxin,Liu Jiadong
The modification of cordierite honeycomb (CH) carrier is conducive to improve the catalytic activity of catalyst that applying in the treatment of real VOCs waste gas. A honeycombed calcium aluminum silicate hydrate (C–A–S–H) thin layer was self-assembled successfully by alkaline corrosion with supersaturated Ca(OH) 2 and contacted robustly onto the CH surface (named as CHC) by chemical bond. CuMnCeO x /CHC catalyst was prepared and applied in microwave catalytic combustion of toluene to check the catalytic activity in this work. Compared with CuMnCeO x /CH catalyst, CuMnCeO x /CHC catalyst exhibited a higher catalytic capacity and the removal rate of toluene reached 99%, which was higher than 75% of CuMnCeO x /CH catalyst under same reaction conditions of toluene initial concentration 1000 mg m −3 , air flow 0.12 m 3 h −1 and bed temperature 200 °C. Based on SEM, BET, XRD, XPS, UV-Raman, H 2 -TPR and NH 3 -TPD characterizations, it showed clearly that honeycombed C–A–S–H thin layer made CuMnCeO x active particles with smaller size more uniformly embedded into the pores of itself to hinder effectively the agglomeration of active particles in reaction. The valence reversible conversion of Cu + /Cu 2+ , Mn 2+ /Mn 3+ /Mn 4+ and Ce 3+ /Ce 4+ and total valence increase of CuMnCeO x produced abundant oxygen vacancies on the catalyst surface and simultaneously improved the transformation of surface adsorbed oxygen (O ads ) to lattice oxygen (O latt ). Toluene was oxidized completely by O ads and O latt species onto the active sites and “hot spots” under microwave irradiation that following both L–H mechanism and MvK mechanism. The research work lays down a theoretical basis for the preparation of highly effective catalyst and further application in the treatment of industrial VOCs waste gas. Graphical Abstract
研究领域:
环境科学
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ENERGY
·
2019
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IF 8.426
Jian Li,Junyu Tao,Beibei Yan,Kexin Cheng,Guanyi Chen,Jianli Hu
Tar abatement and removal is most challenging facing industrialization of biomass gasification technology and its cost-effective removal is indispensably dreamed. Thorough, low-cost and stable removal of toluene, a major compound of biomass tar, was achieved by the microwave catalytic reforming method. A self-designed microwave tube furnace was employed, and toluene was converted with char-supported nickel-iron and nickel-cerium catalysts in an ex situ hot gas conditions. Under the optimal conditions, a 100% toluene conversion efficiency could be achieved, and the hydrogen concentration in the product gas could reach 28.2 vol%. The energy efficiency was 98.97 g/kW h. According to duration tests, the conversion efficiency of nickel-cerium catalysts could still be higher than 90%, even after 8-h successive runs. Comprehensive characterizations of fresh and spent catalysts were conducted, showing agglomeration was the main challenge instead of carbon deposition, which was previously commonly believed. Furthermore, in the pursuit of advancing industrial tar abatement, the depletion and thermal stability of char-supported catalysts were evaluated through a custom-designed gasification-atmosphere-thermogravimetry-mass spectrum analysis. The study provided a breakthrough for the integration of thermal, catalysis and microwave effects for toluene conversion, and the mechanism of char-supported catalysis under specific microwave conditions was also highlighted.
研究领域:
能源与燃料化学
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环境科学
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催化材料科学
✓ 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）