CRYSTENGCOMM
·
2014
·Vol. 17
·期 5
·1168-1172
·
IF 3.858
Shaojuan Luo,Jiyun Feng,Ka Ming Ng
Indium–tin carboxylate precursors were successfully synthesized by a direct reaction of indium and tin metals with a molten fatty acid under a nitrogen atmosphere at 260 °C. A linear relationship between the reaction initiation temperature and the number of carbon atoms of the fatty acids ranging from capric acid to stearic acid was observed. There was a 7 °C increase in the reaction initiation temperature for an increase of one carbon atom in the fatty acid. Nearly monodisperse 7–9 nm ITO nanocrystals without agglomeration were synthesized by direct pyrolysis of the as-synthesized precursors without using additional organic solvents. The fatty acid had a minor effect on the decomposition temperature and the mean ITO particle size, but affected the particle size distribution. TOF-SIMS data confirmed that the residue fatty acids on the surface of the indium tin oxide (ITO) nanoparticles served as a built-in surfactant leading to excellent dispersity of the ITO nanocrystals in non-polar solvents.
研究领域:
材料科学
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纳米技术
·
化学合成
·
表面化学
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DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2021
·
IF 3.178
Qiaoyan Shang,Jifa Xiao,Xiaojuan Liu,Yujie Ling,Wenge Liu,Guanwei Cui,Xifeng Shi,Shuqian Xia,Bo Tang
Biomass pyrolysis oil is a renewable resource and some of compounds (such as ketones, phenols and furans) in biomass pyrolysis oil are very useful compounds that can be used as raw materials for production of fine chemicals. Vapor-liquid equilibrium (VLE) data are critical and fundamental for designing distillation separation process. The VLE experiment and calculation of ketone-related binary systems (2-butanone + cyclopentanone, 2,3-butanedione + cyclopentanone) at atmospheric pressure are studied in this work. Binary interaction parameters of activity coefficient models (NRTL, Wilson and UNIQUAC) are obtained by correlating VLE experimental data. The new group CH 2 COCH 2 is defined and the new group interaction parameters are presented and used to predict VLE data by UNIFAC-DMD model. The distillation separation process of ketones is designed and simulated based on VLE results. This work will provide theoretical basis and technical guidance for industrial separation process of biomass pyrolysis oil.
研究领域:
化学工程
·
可再生能源
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DOI
高影响因子
ENERGY & FUELS
·
2017
·
IF 3.091
Bin Hu,Qiang Lu,Xiao-yan Jiang,Xiao-chen Dong,Min-shu Cui,Chang-qing Dong,Yong-ping Yang
Fast pyrolysis of glucose/cellulose will produce abundant 1,6-anhydro-β-d-glucopyranose (known as levoglucosan, LG) as the predominant anhydrosugar product, together with certain amounts of other anhydrosugars, mainly including 1,6-anhydro-β-d-glucofuranose (AGF), 1,4:3,6-dianhydro-α-d-glucopyranose (DGP), 1,5-anhydro-4-deoxy-d-glycero-hex-1-en-3-ulose (APP), 1-hydroxy-3,6-dioxabicyclo[3.2.1]octan-2-one (LAC). The formation mechanisms of the latter four anhydrosugar products are not well-known at present. Substantiated by analytical pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) experiments, quantum chemistry calculations are employed to give a deep insight into their formation mechanisms in this study. The anomeric effect of glucopyranose has a distinct effect to their formation. DGP is mainly derived from α-d-glucopyranose which plays a vital role in the formation of 1,4-acetal ring. On the contrary, APP and LAC can merely derive from β-d-glucopyranose due to the dehydration at 1-OH + 2-H site. APP is important but not necessary to form LAC, and their formation pathways also compete with each other. Moreover, AGF is not influenced by the anomeric effect of the two anomers, because its formation relies on the acyclic d-glucose.
研究领域:
生物化学
·
分析化学
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DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2020
·Vol. 38
·期 3
·4241-4249
·
IF 5.627
Gongxin Dai,Guanyu Wang,Kaige Wang,Zhongyue Zhou,Shurong Wang
As one of the major components of lignocellulosic biomass , the current understanding on pyrolysis mechanism of hemicellulose is relatively limited compared to that of cellulose due to its random and complicated structure. Here, we reported an in-depth study on hemicellulose pyrolysis by combining advanced experimental techniques and quantum chemical calculation , using xylose , xylobiose and xylan as the model compounds. The structural evolution during pyrolysis was firstly characterized via in-situ diffuse reflectance infrared Fourier transform spectroscopy . The corresponding two-dimensional perturbation correlation infrared spectroscopy analysis shows that the dissociation of side chains dominates in the initial stage of xylan pyrolysis, followed by the cleavage of glycosidic bond and the opening of xylopyranose ring. The release behaviors of condensable vapors from hemicellulose pyrolysis obtained by thermogravimetric analyzer coupled with photoionization mass spectrometry indicate that the pyrolysis of xylan polymer with more side chains is prone to produce small compounds via ring rupture reactions compared to that of xylose and xylobiose . The possible reaction pathways of xylan pyrolysis were proposed based on the experimental results and were further confirmed via quantum chemical calculation. This work expands the size of model compounds from common monomers and dimers without side chains to larger tetramers with side chains. It was found that the dissociation of side chains and the cleavage of glycosidic bonds are competitive reactions. The backbone of xylan is decomposed following the dissociation of side chains to yield furfural , dianhydro xylose and other small compounds.
研究领域:
生物质能源
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热化学转化
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分析化学
·
量子化学
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聚合物热解
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2026
·
IF 16.8
Rong Ding,Rui-Rui Xu,Min Li,Shou-Cui Wang,Guang-Kuo Bao,Min Yang,Fu-Rong Zeng,Hai-Bo Zhao
Phosphorus-assisted, one-step air-pyrolysis carbonization strategy to directly fabricate heteroatom-doped and defect porous carbons from biomass at high temperature. • This method is efficient, universal, and suitable for various biomass/phosphorus raw materials. • An ultra-broad effective absorption bandwidth of 7.68 GHz is achieved at 2.27 mm with a minimum reflection loss of -77.70 dB. • RCS values of P-doped carbons in the far-field were simulated by CST. • Offering an economical route for preparing biomass-derived functional porous carbon materials. Direct air-pyrolysis offers an efficient and attractive route for functional porous carbon materials. However, existing strategies severely suffer from specific precursors, limited yields, and additional agents, posing significant challenges for the scalable, direct conversion of biomass under open-air conditions. Herein, inspired by the intumescent flame-retardant design in polymer science, we present a simple phosphorus (P)-assisted, air-pyrolysis strategy that directly converts various biomass into P-doped porous carbon materials, exhibiting excellent electromagnetic wave absorption. By leveraging various commercial P-containing reagents as synergistic charring/doping agents and biomass with multi-hydroxyls as carbon sources, the mixtures were calcined directly in open-air without inert gas protection. Under the superior catalytic dehydration and charring effects of P, thermally stable P-doped intumescent chars were rapidly fabricated at elevated temperatures, resulting in high-quality porous carbons. Typically, P/PC-1 exhibits the specific surface area of 290.2 m 2 g −1 and a high mass yield of up to 15.5%, achieving an effective absorption bandwidth of 7.68 GHz at 2.27 mm thickness and a minimum reflection loss of up to −77.70 dB (over 99.99999% absorption efficiency). Notably, our P-assisted air-pyrolysis strategy is applicable and scalable for various biomass species. This work demonstrates a facile, direct, and efficient air-pyrolysis carbonization strategy, offering scalable and economical routes for preparing biomass-derived functional porous carbon materials. Download: Download high-res image (343KB) Download: Download full-size image
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Yulin Zhang,Shuo Cheng,Guozhao Ji,Aimin Li
The light fractions of tire pyrolysis oil (TPO) are rich in valuable chemicals, such as limonene, but the utilization of TPO-derived limonene or limonene derivatives was limited by the difficulties to separate limonene from the rest compounds, especially p -cymene which has a similar molecular structure and physical properties (molecular size, melting point and boiling point) as limonene. In order to utilize limonene and separate p -cymene, this study took advantage of the difference in oxidizability between limonene and p -cymene, and proposed a method of epoxidizing TPO before the separation. After epoxidation, limonene was successfully converted into limonene epoxides, while aromatic compounds in TPO such as p -cymene were inert and non-oxidizable. Limonene epoxides have a higher boiling point than p -cymene, so the limonene epoxides can be easily refined by distillation. In order to accelerate the oxidation of limonene, a peroxophosphotungstate catalyst was used as a sustainable solvent-free process. The fraction of TPO between 160 and 190 °C which has 298 g/L limonene was tested in this study. The epoxidation of the TPO 160-190 could reach complete conversion to limonene 1,2-oxides and diepoxide limonene. The resulting oil could be divided into p -cymene enriched fraction and limonene epoxides enriched fraction by simple distillation, and the limonene epoxides enriched fraction contained more than 80% of limonene epoxides. The catalytic mechanism was proposed with the assistance of FT-IR, GC–MS, and 31 P NMR analysis. This work presents a novel strategy of epoxidizing limonene for limonene epoxide and p -cymene separation, which could bring a breakthrough for limonene epoxide and p -cymene production from waste-derived oils.
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产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2023
·
IF 5.9
Miao Wang,Shuai Zhang,Xiangjun Liu,Yayun Ma,Junqi Wang
A comprehensive study of alkali and alkaline earth metal (AAEM) salts including two different anions (Cl - and CH 3 COO - ) in the catalytic pyrolysis of cellulose to produce levoglucosan (LG), bio-oil, and biochar were investigated. At the same time, the catalytic pyrolysis mechanism was also speculated. The thermogravimetric analyzer (TGA) and lab-scale fixed-bed reactor system were used to determine the thermal degradation process and the pyrolysis products of LG, bio-oil, and biochar. The optimized pyrolysis parameters were obtained by using Box-Behnken design-response surface method. According to the results, AAEM salts significantly boosted the yield of biochar, as well as greatly cut down the output of LG and bio-oil. The rank of effect on LG yield was as follows: CaCl 2 , MgCl 2 > CH 3 COOK, CH 3 COONa > (CH 3 COO) 2 Mg, (CH 3 COO) 2 Ca > KCl, NaCl. Moreover, the addition of AAEM salts considerably dropped the activation energy E of cellulose pyrolysis as well as prompted microcrystalline cellulose pyrolysis under lower temperatures. This study was pivotal in deducing the pathway of cellulose pyrolysis, thereby offering critical insights to hasten the progress of biomass utilization.
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产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2022
·Vol. 148
·期 3
·789-805
·
IF 4.755
Zhu Di,Huang Zhixiong,Shi Minxian,Qin Yan,Zou Zhenyue,Deng Zongyi
BPR has been widely used as ablative material for thermal protection on aircraft surface. In this study, model-free method was employed to study the kinetic models of BPR and ZrSi 2 /B 4 C-Ph composite. In addition, the thermal stability, chemical reaction and structure evolution during pyrolysis of ZrSi 2 /B 4 C-Ph composite were characterized by TGA, XRD, XPS, GC–MS and TG-MS. The results indicated that the pyrolysis of BPR includes three consecutive and overlapping stages. And the kinetic mechanism function f(α) , apparent activation energy E a and pre-exponential factor A of each stage were confirmed. Besides, the high char yield of ZrSi 2 /B 4 C-Ph composite is mainly attributed to the reaction of ZrSi 2 and B 4 C with gases released during BPR pyrolysis, which formed solid phases such as amorphous carbon, ZrO 2 , SiO 2 and B 2 O 3 .
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产品关联
DOI
高影响因子
International Journal of Environmental Research and Public Health
·
2023
·Vol. 20
·期 4
·2841
·
IF 4.614
Qinghong Li,Huan Yang,Ping Chen,Wenxue Jiang,Fei Chen,Xiaorong Yu,Gaoshen Su
The co-pyrolysis of oily sludge and walnut shell is a reliable method for solid waste treatment and waste recycling. In this paper, a thermogravimetric analysis was used to study the thermodynamics and synergy effect of oily sludge (OS) and walnut shell (WS) at four heating rates (10, 20, 30, and 40 °C/min) in the temperature range from 50–850 °C. Two model-free methods (FWO and KAS) were used to calculate the activation energy. The results showed that the heating rate had no significant effect on the pyrolysis process. The addition of walnut shell improved the pyrolysis process of the samples. Mixture 1OS3WS had a synergy effect, while other blends showed an inhibitory effect. The synergy effect of co-pyrolysis was strongest when the mass ratio of oily sludge was 25%. The activation energy of the Zn-ZSM-5/25 catalyst was the lowest, and the residual substances were the least, indicating that the Zn-ZSM-5/25 was beneficial to the co-pyrolysis of oily sludge and walnut shell. The analysis of catalytic pyrolysis products by Py-GC/MS found that co-pyrolysis was beneficial to the generation of aromatic hydrocarbons. This study provided a method for the resource utilization of hazardous waste and biomass waste, which was conducive to the production of aromatic chemicals with added value while reducing environmental pollution.Keywords:oily sludge;co-pyrolysis;biomass;ZSM-5
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产品关联
DOI
PubMed
高影响因子
FUEL
·
2023
·
IF 7.4
Deng Zhao,Haoyuan Feng,Yu Wang,Fei Wang,Huashan Wang,Hua Liu,Hui Liu
The influence mechanism of alkali metal potassium (K) on cellulose pyrolysis is a vague and fundamental key topic in the field of biomass thermal conversion. In this study, the pyrolysis of cellulose and K-impregnated cellulose was compared by in-situ DRIFTS (Diffused Reflectance Infrared Fourier Transform Spectroscopy) and TG (Thermal Gravimetric)–MS (Mass Spectrum) experiment, and quantum chemical calculations were used to verify the peak position and pyrolysis mechanism of infrared (IR) spectroscopy. Stepwise isothermal in-situ DRIFTS was designed to study the reaction path at high temperatures. It was found that in the early stage of pyrolysis, K accelerated the activation of cellulose by attacking the hydrogen bond (H-bond) in the crystal structure of cellulose, increased the dehydration rate between molecules, and promoted the decomposition of cellulose. Simultaneously, it weakened the epoxy–ether bond, inhibited the formation of dehydrated sugar, and promoted the formation of furan. Subsequently, K combined with carbonyl groups to form C–O–K structures, which improved the thermal stability of certain oxygen-containing functional groups such as carbonyls/aldehydes, so that these structures were retained until higher temperature. K promoted the conversion of dehydrated sugars to straight-chain ketones/aldehydes, which led to an increase in carbon conversion. During the coke generation stage, K promoted the formation of disordered carbon and residues, thereby inhibiting coke aromatization. The isothermal in-situ DRIFTS method proposed in this study was demonstrated to better inhibit the high temperature drift of IR spectrum during pyrolysis. It clarified the conversion between functional groups at high temperatures, which is expected to promote the development of other high-temperature pyrolysis mechanism.
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产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2023
·
IF 8.7
Yun Zhang,Chuanbiao Zhang,Wenjuan Li,Qiuping Xiao,Fengyuan Jiao,Sen Xu,Yanhua Lan,Yizheng Fu,Chi-Min Shu,Weiguo Cao
Stearic acid provides a basis for developing renewable energy, such as solar energy and biomass energy. A thermogravimetric-infrared spectroscopy (TG-IR) experimental test is conducted to obtain the thermal decomposition progress and the main gaseous products of stearic acid. The result shows that small gaseous products (H 2 O, CO 2 , CO, alkanes, olefins , etc.) are released. Furthermore, the method of reactive molecular dynamics simulation (ReaxFF-MD) is utilized to look into the pyrolysis reaction mechanism of stearic acid. The main pyrolysis products of stearic acid received by ReaxFF-MD are C 2 H 4 , H 2 , C 2 H 2 , CH 4 , H 2 O, CO 2 , and CO, consisting of the result of the TG-IR test. The effect of the simulated system density and temperature on the distribution of main products is also explored. Also, the thermal kinetic analysis is conducted by the initial consumption of stearic acid under different temperatures. The primary reaction mechanism of stearic acid pyrolysis is that the stearic acid molecules dissociate through C–C bonds break to generate C 2 H 4 , CH 4 , C 2 H 2 , C 3 H 6 , and other small molecules and radicals, and a typical reaction mechanism scheme of stearic acid pyrolysis is presented. The results provide a reference for explaining the macroscopic explosion characteristics of dust at the microscopic mechanism level.
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产品关联
DOI
高影响因子
Journal of Central South University
·
2023
·Vol. 30
·期 5
·1523-1538
·
IF 4.4
Xu Jia-qi,Liu Wei,Jiao Fen,Han Jun-wei,Qin Wen-qing,Cai Can
Pyrolysis is a promising technology to treat waste printed circuit boards (WPCBs) with significant advantages of full source utilization, high separation efficiency and scarce pollutant emissions. In this work, TG and DTG analyses were performed to determine pyrolysis characteristics. The kinetic analysis adopting the Starink Kissinger-Akahira-Sunose (SKAS) model was conducted to confirm the apparent activation energy ( E α ). Pyrolysis products were collected using a lab-scale pyrolyzer. GC-MS analysis coupled with MS-DIAL data processing was applied to clarify the distribution pattern of valuable liquid products. The results indicated that the main thermal decomposition of WPCBs occurred within the temperature range of 157–664 °C, with E α ranging from 80.70 to 279.46 kJ/mol. During pyrolysis, the WPCBs were converted into three kinds of products, in which solid and gas products could be applied in the field of materials and energy. The composition of WPCBs oil products was complicated and sensitive to the pyrolysis temperature. The largest proportion of valuable liquid products (82.94%) was obtained at 600 °C, containing 52.87% monocyclic aromatic phenols, 4.39% polycyclic aromatic phenols, 3.07% brominated phenols, and 22.61% hydrocarbons, respectively. These valuable liquid products would be an attractive alternative as raw materials for the synthesis of phenolic resins and the production of petrochemicals.
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）