BioEnergy Research
·
2015
·Vol. 8
·期 3
·1263-1274
·
IF 3.541
Zhang Zhi-bo,Lu Qiang,Ye Xiao-ning,Wang Ti-peng,Wang Xian-hua,Dong Chang-qing
Solid phosphoric acid (SPA) catalysts with different carriers were prepared and used for catalytic fast pyrolysis of poplar wood to produce levoglucosenone (LGO), a valuable anhydrosugar derivative that can be used in various organic synthesis applications. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) experiments were performed to evaluate the catalytic capabilities of these catalysts under different reaction conditions. The results indicated that SPA catalyst prepared with the SBA-15 carrier exhibited the best catalytic capability for selectively producing LGO. Both the catalytic pyrolysis temperature and catalyst-to-biomass ratio affected the pyrolytic products greatly. The maximal LGO yield reached as high as 8.2 wt% from poplar wood, obtained at the pyrolysis temperature of 300 °C and the catalyst-to-biomass ratio of 1. The by-products during the catalytic pyrolysis process were mainly acetic acid (AA) and furfural (FF). In addition, the SPA catalyst possessed better catalytic capability than the liquid phosphoric acid (H 3 PO 4 ) catalyst to produce LGO.
研究领域:
生物能源
·
催化化学
·
生物质转化
·
热解化学
·
绿色化学
·
可再生资源利用
✓ 已验证
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 1
·377-388
·
IF 3.049
Tianyu Wu,Wenqing Zhang,Xin Jin,Xiangyi Liang,Gang Sui,Xiaoping Yang
Carbon fiber-reinforced polymer composites have been widely used in various fields and have inevitably produced large amounts of composite waste. The recycling of carbon fibers with high value has become an active research topic at related institutions and production enterprises. In this paper, the catalytic pyrolysis of T700 carbon fiber/epoxy composites in molten salt was studied. Due to the efficient solubility of molten ZnCl2 for the epoxy matrix and catalytic fracture of the C–N bonds by the action of Zn2+ ions, the epoxy composites can be completely degraded at 360 °C in 80 min under standard pressure, and the reclamation efficiency was significantly enhanced compared with conventional pyrolysis reclamation without a catalyst. The types and contents of the main oxygen-containing functional groups on the surfaces of the fibers reclaimed with ZnCl2 were similar to those of the virgin fibers, and the graphitization structure of the carbon fibers was not destroyed in the pyrolysis process. The tensile strength of a monofilament of the fibers reclaimed with ZnCl2 was obviously higher than that of fibers reclaimed in air; it reached a high retention rate that was about 95% that of the virgin fibers. The fibers reclaimed with ZnCl2 after sizing exhibited a desirable reinforcing effect on the flexure performance and interlaminar shear strength of unidirectional carbon fiber/epoxy composites which was close to the performance levels of composite samples containing commercial T700 carbon fibers. Therefore, efficient technology to reclaim high-quality carbon fibers from epoxy matrices has been devised.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Progress in Natural Science-Materials International
·
2018
·Vol. 28
·期 4
·529-533
·
IF 2.572
Zhenmin Ding,Yufei Ma,Dandan Peng,Lu Zhang,Yumeng Zhao,Yuan Li,Shumin Han
In this work, LiBH 4 –20 wt% PP composite was prepared by ball-milling with as-synthesized hierarchical pyrolysis polyaniline (PP) and LiBH 4 , and the hydrogen sorption performance as well as catalytic mechanism of the composite was studied. It is found that the onset desorption temperature of the composite decreases to 75 °C, almost 235 °C lower than that of the milled LiBH 4 . Moreover, the composite could release 4.1 wt% H 2 and rehydrogenate a total of 4.4 wt% H 2 when the temperature raiseds up to 400 °C, showing an outstanding reversibility, which even 3.9 wt% H 2 can be kept after five cycles. Through scanning electron microscopy (SEM) observation and X-ray diffraction (XRD) analysis, we found that the PP surface forms some nanoholes after hydrogenation-dehydrogenation cycles, which leads to the confinement of some LiBH 4 in the PP nanoporous structure, therefore, the hydrogen sorption kinetics and reversibility are significantly enhanced. In addition, we also found the oxygenic groups of the PP can react with LiBH 4 forming LiBO 2 and Li 3 BO 3 , where the containing Li–B–O bonds loaded in the porous structure of the PP catalyze the hydrogenation reaction of LiBH 4 .
研究领域:
材料科学
·
能源化学
·
纳米材料
·
固态储氢
·
催化化学
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2012
·
IF 3.285
Yi Liu,Hai-Xiao He
Mesoporous alumina with a narrow pore size distribution is synthesized by direct thermolysis of Al-based coordination polymer. By applying the appropriate thermolysis temperature, both high surface area and large pore volume are obtained with the collapses and elimination of the 1,4-benzenedicarboxylate linkers of Al-based coordination polymer. This new class of mesoporous alumina display better adsorption properties and higher thermal stability, which retain mesoporous properties and high surface area after calcination in 900 °C. This thermolysis method provides a new approach to synthesize mesoporous alumina with high thermal stability by using coordination polymers.
研究领域:
材料科学
·
无机化学
·
纳米材料
·
多孔材料
·
热分析
✓ 已验证
DOI
高影响因子
JOM
·
2020
·Vol. 72
·期 9
·3179-3185
·
IF 2.054
Wang Xun,Jiao Fen,Qin Wenqing,Li Zihan,Wang Na,Liu Wei,Yang Congren
Waste printed circuit boards (WPCBs) are an essential component in electronic waste (e-waste), and contain a number of valuable metals (e.g., Cu, Sn) as well as non-metal resources (e.g., brominated epoxy resin). Currently, most of the non-metals are disposed of in landfills, causing environmental problems. In this study, a combination of pyrolysis and physical separation is proposed to recover valuable resources, including both metals and non-metals, from WPCBs. The WPCBs were pyrolyzed at 700°C under a nitrogen atmosphere. Pyrolysis oil and gas can be reused as fuel for the pyrolysis of WPCBs. Metals like copper, tin, and iron in the pyrolysis residues were separated by selective crushing, sieving, gravity separation, and magnetic separation. Finally, rich copper (Cu 82.21%, Sn 1.47%), rich tin (Cu 53.20%, Sn 13.43%), rich iron (Fe > 63%), and non-metal products were obtained, and the total recoveries of copper, tin, and iron were 95%, 86%, and 76%, respectively.
研究领域:
环境科学
·
资源循环利用
·
冶金工程
·
固体废物处理
·
清洁生产技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 98
·55256-55262
·
IF 3.708
Zhijian Wu,Ya Xiong,Guoqiang Guan,Lingjun Kong,Shuanghong Tian
A new pyrolytic process was successfully used to prepare hollow-like spherical sludge chars (HSC). In the process, pre-formed cotton spheres with a low density were firstly coated by a layer of sludge paste containing ZnCl2 to form cotton fiber@sludge spheres and then pyrolyzed at 500 °C for 2 h. The resulting HSC possessed a diameter of about 3 mm, a low density of 0.1008 g cm−3 and a high surface area of 1008 m2 g−1. The column adsorption behavior showed that the adsorption capacity and rate constant of HSC for methylene blue reached 186.4 mg g−1 and 0.232 mL min−1 mg−1. The adsorption capacity is about 8.4 and 12 fold of the adsorption capacities of GAC (22.28 mg g−1) and SC (15.26 mg g−1), respectively, and the adsorption rate constant is about 1.3 fold of that of GAC and SC. The great adsorption capacity and rate constant can be considerably dependent on the special hollow-like spherical structure of HSC.
研究领域:
环境科学
·
材料科学
·
化学工程
·
污染控制
·
吸附技术
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Libo Deng,Wenhua Zhong,Jubei Wang,Peixin Zhang,Haoming Fang,Lei Yao,Xuqing Liu,Xiangzhong Ren,Yongliang Li
Biomass-derived carbons have been extensively researched as electrode material for energy storage and conversion recently. However, most of the previous works convert crude biomass directly into carbon and the electrochemical capacitances for the resultant carbons are quite often underestimated as well as large variations in capacitances exist in literatures due to the complex nature of biomass, which practically hinder their applications. In this work, polysaccharide nanofibers were extracted from an inexpensive natural fungus using a hydrothermal method and were converted to porous carbon nanofibers (CNFs) by potassium hydroxide activation. The porous carbons were assembled into symmetric supercapacitors using both potassium hydroxide and an ionic liquid (IL) as electrolytes. Solid state nuclear magnetic resonance characterization showed that the micropores of the as-prepared carbons are accessible to the IL electrolyte when uncharged and thus high capacitance is expected. It is found in both electrolytes the electrochemical capacitances of CNFs are significantly higher than those of the porous carbon derived directly from the crude fungus. Furthermore, the CNFs delivered an extraordinary energy density of 92.3 Wh kg −1 in the IL electrolyte, making it a promising candidate for electrode materials for supercapacitors.
研究领域:
材料科学
·
能源化学
·
纳米技术
·
电化学
·
可再生能源
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·Vol. 49
·期 14
·23538-23545
·
IF 5.2
Jianbo Zhu,Jing Lin,Chao Yu,Yi Fang,Zhenya Liu,Zhonglu Guo,Chengchun Tang,Yang Huang
Boron nitride (BN) aerogels is a class of three-dimensional (3D) hierarchical network structure assembled from BN micro/nanostructures. The construction of BN/BN composite aerogel by introducing of BN micro/nano-structural units into the 3D BN aerogel scaffold provides an effective strategy for obtaining BN aerogel with improved all-round properties. Here, a novel kind of BN/BN composite aerogels has been developed by vacuum impregnation of ammonia borane (AB) into fiber-based BN aerogels, followed by high-temperature pyrolysis . The introducing of AB into BN aerogels makes the formation of unique AB/BN composite aerogels, and the high-temperature decomposition of AB results in the obtaining of a series of multifunctional composites, i.e. BN/BN composite aerogels. As compared with the porous BN microfibers in original BN aerogel, the self-assembled fibers in BN/BN composite aerogel are densely covered with high crystalline BN nanoflakes, which are generated by the AB decomposition. The obtained BN/BN composite aerogels have shown excellent thermal stability, significantly improved hydrophobic effect and heat transfer capability. This work provides a new idea for the future research and development of BN composite aerogels.
研究领域:
材料科学
·
纳米材料
·
热功能材料
·
多孔材料
·
复合材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2023
·
IF 6
Bingyang Li,Meiqian Chen
Massive spent ion exchange resins (SIERs) containing radionuclides are produced in nuclear power plants , which need to be treated reasonably. The migration mechanism of nuclides in SIER in both pyrolysis and gasification was evaluated from the chemical equilibrium analysis based on the Gibbs free energy minimization. The maximum volatility degrees of Co, Sr and Cs at 400–600 °C and 0.1 MPa were 0.01%, 0% and 0.1% in the pyrolysis . The maximum volatility degrees of Co, Sr and Cs were 0.015%, 0% and 100% at 600–1300 °C and 0.1 MPa in the gasification, and the steam concentration should be set mainly how to limit the volatilization of radionuclides . To reduce the volatility of nuclides as much as possible, the temperatures should be kept below 600 °C and 870 °C in the pyrolysis and gasification, respectively. The volatilization of Cs was greatly inhibited with lifting the pressure from 0.1 MPa to 1.5 MPa, which decreased from 0.103% to 0.007% in the pyrolysis (600 °C) and from 4.80% to 0.30% in the gasification (715 °C), respectively. Based on preventing the nuclides leakage, the negative pressure in the gasification should be controlled between 0.097 and 0.099 MPa. The volatilization of radionuclides was effectively weakened by adding a fixative, Zr(HPO 4 ) 2 ·H 2 O, since it could be helpful to reduce the gaseous cesium-based products in the pyrolysis and gasification. The volatility degree of Cs was close to 0 if Zr/Cs was great than or equal to 0.5. This study could provide basic data for the pyrolysis and gasification treatment of SIER.
研究领域:
核化学
·
环境工程
·
放射化学
·
废物处理
·
热力学分析
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Zixiang Gao,Jun Liu,Ying Wang,Yuqiong Zhao,Guoqiang Li,Wenzhe Si,Yuefeng Liu,Guojie Zhang
Activated carbon (AC) adsorbents are extensively utilized for the adsorption and elimination of volatile organic compounds (VOCs), such as styrene, owing to their remarkable adsorption capacity and cost-effectiveness. However, the regeneration and reutilization of activated carbon face significant limitations due to incomplete cleavage of styrene and carbon accumulation during heated styrene cracking. This research focuses on the preparation of Ni-Fe bimetal-enriched adsorbent columns by successfully loading transition metals Ni and Fe onto activated carbon saturated with styrene adsorption using a simple impregnation method. A series of characterizations were conducted to unveil the formation process of active sites in the alloy phase and the mechanism behind the synergistic anti-accumulation effect of Ni and Fe on carbon deposits. Furthermore, the adsorption performance of the regenerated activated carbon for styrene was evaluated. The results revealed the formation of Fe 0.64 Ni 0.36 and Ni-Fe alloy (Kamacite) phases on the activated carbon carriers, which enhanced the cracking of styrene and exhibited superior anti-carbon accumulation properties. The styrene adsorption capacity of the synthesized bimetallic 2.5Fe-2.5Ni-900 regenerated sample reached 407.5 mg/g, approximately 1.5 times higher than that of the monometallic samples 5Fe-900 and 5Ni-900, and 1.6 times higher than that of the unmodified activated carbon RAC-900. Furthermore, kinetic studies indicated that the adsorption process of styrene by the samples followed a multilayer adsorption mechanism, predominantly governed by physical adsorption. Intra-pore diffusion was identified as the primary rate-determining step during the adsorption process. Moreover, after three regenerative adsorption cycles, the decrease in styrene adsorption capacity for the 2.5Fe-2.5Ni-900 sample was below 20 %. This study presents novel perspectives and methodologies for addressing the regeneration challenge of activated carbon saturated with styrene adsorption.
研究领域:
环境化学
·
吸附科学
·
材料再生
·
大气污染控制
·
环境功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Chuyuan Huang,Xianfeng Chen,Bihe Yuan,Hongming Zhang,Sheng Shang,Qi Zhao,Huaming Dai,Song He,Ying Zhang,Yi Niu
Flame propagation characteristics of wood dust deflagration and suppression mechanism of ultrafine powders are investigated systematically. The deflagration reaction intensity of wood dust increases firstly and then decreases with the increase in dust cloud concentration. This is due to factors such as oxygen supply, positive feedback among flame characteristic parameters. Thus, there is an equivalent dust concentration for greatest deflagration intensity. Nano-sized ultrafine zirconium hydroxide (Zr(OH) 4 ) and silicon dioxide (SiO 2 ) powder are introduced to suppress wood dust deflagration at the equivalent concentration. It is found that Zr(OH) 4 has a suppression effect of endothermic decomposition to generate zirconia (ZrO 2 ), dilution of oxygen and absorption of free radicals; while SiO 2 exerts suppression effect due to its high melting point and heat absorption. The suppression performance of Zr(OH) 4 is better than that of SiO 2 . This is because that Zr(OH) 4 and ZrO 2 have a catalytic carbonization effect. It can not only improve thermal stability of wood particles by catalyzing production of high-temperature resistant residuals, but also promote the formation of catalytic sites to reduce crystallite size of carbon layer on wood particles surface, weakening heat and mass transfer between particles.
研究领域:
安全工程
·
燃烧学
·
粉尘爆炸防控
·
材料化学
·
热力学
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2020
·Vol. 31
·期 11
·2480-2491
·
IF 2.578
Po Hu,Xinyu Zheng,Jiwei Zhu,Baolin Wu
Chicken feather keratin (CK), a biomaterial that contains a large amount of nitrogen is extracted from chicken feathers and has significant potential for use as a flame retardant. In this study, CK and 9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide (DOPO) were added in different amounts to an epoxy resin (EP), and their flame retardancy and smoke suppression effects were studied. The results showed that CK exhibits a good flame-retardancy effect and better smoke suppression characteristics than those of DOPO when added to EP. Furthermore, it greatly reduces the CO yield in smoke. While the EP samples with DOPO showed better flame-retardancy properties than those of the samples with CK, they also produced more smoke, which had a higher CO content. Furthermore, when CK and DOPO were added to EP together, the flame-retardancy characteristics of the samples varied with the CK/DOPO ratio. Then the pyrolysis of all samples was divided into two stages based on thermokinetics analysis and the activation energies of these samples in the two stages were investigated. Finally, the flame-retardancy mechanism was discussed. When samples burn, the PO· free radicals derived from DOPO combine with H· and OH· to induce a quenching effect. In addition, the phosphate resulting from the decomposition of DOPO promotes the formation of the char layer. At the same time, the noncombustible gases generated during the pyrolysis of CK cause the char layer to expand and remove some of the heat. Thus, CK and DOPO synergistically improved the flame retardancy of EP.
研究领域:
高分子材料科学
·
阻燃化学
·
热分析
·
环境友好材料
·
生物基添加剂
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）