JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2022
·
IF 6.437
Koïta Djakaria,Ziyue Tang,Jingai Shao,Xu Chen,Haoyu Xiao,Joseph Smith,Haiping Yang,Hanping Chen
Furfural is one of the top valuable building block chemicals, the selective production of furfural from biomass has attracted increasing concerns in recent years. In this work, a novel method for the selective production of furfural through cellulose catalytic pyrolysis with WO 3 /γ-Al 2 O 3 was reported, and the synergistic effect between γ-Al 2 O 3 and WO 3 was explored. Compared with cellulose pyrolysis alone, the addition of γ-Al 2 O 3 improved the selectivity of furans and greatly inhibited the formation of sugars; while, WO 3 addition promoted the formation of levoglucosenone . When (20–40%) WO 3 /γ-Al 2 O 3 were added, the amount of sugars was further reduced, and the yields of furans (furfural and 2-methylfuran, in particular) were further increased at the same time. Under the optimum conditions (temperature = 600 °C, residence time = 15 s, and catalyst to cellulose mass ratio of 4), 30%WO 3 /γ-Al 2 O 3 showed the best performance, and the selectivity and yield of furfural were improved by nearly 100% and 300%, respectively, as compared with cellulose pyrolysis alone. In addition, compared with γ-Al 2 O 3 , the addition of 30%WO 3 /γ-Al 2 O 3 further increased the yield of furfural and 2-methylfuran to about 50% and 200%, respectively. The high selectivity and yields of furans with WO 3 /γ-Al 2 O 3 addition might be due to that WO 3 crystals in the composite promote the formation of levoglucosenone, which is further converted to additional furans through the Lewis acid sites of γ-Al 2 O 3 . The study may provide some meaningful advices for improving the production of furfural from green catalytic pyrolysis of cellulose.
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高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2021
·
IF 5.541
Fanggang Liu,Lijun Jin,Yanpeng Ban,Haoquan Hu
To understand the pyrolysis behavior of long linear alkanes, six n-alkanes (n-C n H 2n+2 , n = 10, 12, 13, 14, 15, 16) were conducted by pyrolysis coupled with photoionization molecular-beam mass spectrometer at pressure below 10 Pa and temperature between 200 °C and 1000 °C. Lots of important alkyl and alkenyl radicals (CH 3 , C 4 H 9 , C 8 H 15 , C 9 H 19 , C 3 H 5 , C 5 H 9 , etc.), which are the direct evidence to understand the pyrolysis reaction pathway, were real-time detected by mass spectral detector. The results suggested that the predominant pyrolysis mechanism of n-alkanes is a free-radical chain mechanism, beginning with the C C bond homolysis of n-C n H 2n+2 to produce primary alkyl radicals (C m H 2m+1 , m < n) and termination by β C-H homolysis and mutual combination of radicals. The chain is propagated by the β C-C homolysis and H-abstraction of primary alkyl radicals to produce secondary alkyl radicals (C h H 2h+1 ), and then the β C-C homolysis and H-abstraction of the secondary alkyl radicals to form alkyl/alkenyl radicals (C h H 2h+1 /C k H 2k-1 , h ≤ n, k < n-3) and alkenes (C k H 2k /C k H 2k-2 ) and the hydrogen-shift to form free-radical isomers. During the process, H-abstrction, and hydrogen-shift reactions exist as a synergistic reaction. In addition, the position of free radical in alkyl isomers is closer to the central carbon at low temperature. With the increase of temperature, 2-C m H 2m+1 radical are gradually dominated.
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Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Deyong Che,Liye Wang,Hongpeng Liu,Baizhong Sun,Shuai Guo
Biomass pyrolysis has attracted attention; however, its development has been restricted by the formation of NOx precursors, which result mainly from protein pyrolysis. In addition, the effect of lipids on this process is not clear. We extracted proteins and lipids from chlorella and sewage sludge to investigate the thermal decomposition characteristics, thermodynamic properties, kinetic parameters, and reaction mechanisms of protein with or without lipids. Two model-free methods Flynn-Wall-Ozawa (FWO) and Friedman (FM) were used to calculate the kinetic energy. Between 150 and 600 ℃, the average activation energy (E) of sludge protein was 73.63 kJ/mol (FM) or 72.53 kJ/mol (FWO), whereas with lipids, it was 129.19 kJ/mol (FM) or 124.55 kJ/mol (FWO), indicating that lipids restrict the pyrolysis of sludge protein. There was no significant difference between E of chlorella protein pyrolysis with or without lipids. Moreover, the proteins in sludge and chlorella released less NH 3 under the influence of lipids; however, the formation of HCN was affected slightly. The results of this study provide a reliable reference for the regulation of protein pyrolysis, considering the production of NOx precursors.
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高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2021
·
IF 5.541
Xin Zhong,Hu Wang,Qingming Zuo,Zunqing Zheng,Jinglan Wang,Wenhao Yin,Mingfa Yao
Polyoxymethylene dimethyl ethers (DMM n ) is regarded as a potential alternative fuel for transportation utilization. The jet stirred reactor (JSR) pyrolysis of DMM 1−3 was studied at temperatures of 450∼1080 K and pressures of 1.03 atm with the residence time (τ) of 2 s. A gas chromatography/mass spectrometry (GC–MS/FID) was used to detect and provide reliable pyrolysis experimental data. Seven key pyrolysis products were detected and measured in the present work, including fuel, methyl formate, methanol, acetaldehyde, methane, ethane and ethylene. A detailed kinetic model of DMM 1−3 pyrolysis was elaborated. Both rate of production (ROP) and sensitivity analysis were performed to reveal the DMM 1−3 pyrolysis processes. Results show that the chemical kinetic simulation can reproduce the consumption of fuel and most intermediate species reasonably well. With the increase of n from 1 to 3 inside DMM 1−3 , the reactivity increases evidently and the initial pyrolysis temperature decreases significantly, which is mainly resulted from different fuel-specific chain initiation reactions of DMM 1−3 . Methane and methyl formate are two detected key species with relatively significant concentrations. It was revealed that the fuel-specific chain initiation reactions of DMM 1−3 can also significantly affect the production and consumption paths of methyl formate. In addition to the major production and consumption paths of formaldehyde, two key competitive channels were found to perform relatively high negative sensitivity to formaldehyde production of DMM 2 and DMM 3 .
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Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 38
·13447-13459
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IF 7.393
Junyao Shen,Danfeng Zhang,Qibai Wu,Yan Wang,Heng Gao,Jiale Yu,Guoxun Zeng,Haiyan Zhang
Given its easy-to-tailor microstructure with mixed nanodomains including amorphous and pseudo-graphitic parts, hard carbon (HC) as a type of non-graphitizable carbon promises to play a role in extended selection for novel metal/carbon microwave absorbers. Herein, we report the preparation of FeCoNi@HC composites as electromagnetic (EM) absorbers at different pyrolysis-controlled temperatures, derived from FeCoNi nanosheets (NSs)@polyimide (PI) composites. According to suitable pyrolysis treatments, FeCoNi@HC composites exhibit a wide range of mixed morphologies constituted of nanosheets and nanoparticles: original FeCoNi NSs are thermally converted into a particle-like structure as the core; the HC derived from the polyimide (PI) matrix inherits the original framework of the FeCoNi NSs for varying degrees of pyrolysis as the shell. The heat treatments also strongly influence the inner HC structural properties, including defect feature and graphitization degree. Treated by a moderate degree of pyrolysis, the optimal sample achieves decent enhancements of lossy attenuations (e.g., dielectric/magnetic losses) and promoted impedance matching for excellent EM absorption performances. The minimum reflection loss (RL) of the optimal sample is −61.12 dB, along with an effective absorption bandwidth (RL ≤ −10 dB) of 5.53 GHz. We anticipate that this work may enrich the survey of metals/carbon absorbers with non-graphitizable carbon supports.
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高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2021
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IF 5.541
Shengxiong Huang,Yifeng Su,Wei Luo,Qian He,Sheng Huang,Nan Zhou,Zhi Zhou
Pyrolysis is a research hotspot for realizing Chinese Herb residue (CHR) treatment and resource utilization, but there is little reported about in-situ no support catalytic pyrolysis of CHR. In this work, kinetics and no support catalytic pyrolysis characteristics of CHR were studied using a thermogravimetric analyzer and a fix-bed reactor system, respectively. Three groups: Ni-Fe, Ni-Cu and Ni-Co add into CHR and three kinetic methods: Coats-Redfern (CR) method, Flynn-Wall-Ozawa (FWO) method and Distributed Activation Energy Model(DAEM)use for calculate the activation energy, then analyses the gas, bio-oil and char of CHR pyrolysis. The results show that, catalysts can reduce the pyrolysis reaction activation energy. In FWO and DAEM model, the reaction activation energy will increase sharply if the conversion over 0.7. Compare with no catalyst group, add catalyst can restrain gas generation but good for oil production and char formation. Meanwhile, the surface of char is smoother than no catalyst. After test the char, we find that, metals of Ni, Fe, Cu and Co almost enrich in char, which may reuse as catalytic. This study may provide a feasible direction for the industrial application of CHR.
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Journal of Cleaner Production
·
2021
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IF 9.297
Ya Gao,Tong Yue,Wei Sun,Dongdong He,Chenglong Lu,Xinzhuang Fu
Acid recovering and iron recycling from pickling waste acid are the desired goal of the steel mills for current ecological requirements and economic benefit. This study proposed a novel method to treatment the pickling waste acid using extraction separation of ferric chloride and hydrochloric acid , following by the spray pyrolysis of ferric chloride stripping liquor. Comparing the Ruthner method, the significant technical advantages of this method is the lower treatment load and operating costs for the spray pyrolysis process, attributing to the reuse of most hydrochloric acid without iron powder neutralizing. Different extractants (TBP, CYC, IA, OA, and PA) are compared to extract ferric ion from high-concentration hydrochloric acid solution and the optimum conditions are researched. Spectroscopic analysis is performed to characterize iron state in extractants. For the stripped solution, spray pyrolysis is employed to produce high-purity Fe 2 O 3 fine particles, meanwhile hydrochloric acid is recovered for following pickling procedure. The results showed that the effect of CYC under lower O/A ratio was better than that of TBP, and the opposite occurred at higher ratios. Three-stage extraction efficiency can reach over 80% at O/A = 2:1. The final O/A ratio of 1:1 was chosen for the stripping of iron-loaded extractants. Raman and UV–visible found that it was [FeCl 4 ] - anion that existed in Fe-loaded TBP and CYC. Spray pyrolysis at 1000 °C can obtain fine pure Fe 2 O 3 and hydrochloric acid. Eventually, a feasible technological process was put forward to recycle all chemicals and achieve zero emission of water and solid waste in the whole process.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 36
·50500-50509
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IF 4.223
He Qian,Huang Shengxiong,Luo Wei,Su Yifeng,Xia Mao,Zhou Nan,Zhou Zhi
In-situ catalytic pyrolysis has simple process configuration and low cost. Ex-situ catalytic pyrolysis can optimize the pyrolysis capacity and upgrade catalysis, and the catalytic can be reused. But there have been few studies researched on compare in-situ and ex-situ catalytic pyrolysis of the OS performed in similar reactor with two kinds of catalytic. This paper study the pyrolysis of oily sludge (OS) uses CaO and oily pyrolysis char as catalytic at 700 °C. Through analysis the pyrolysis oil (PO), pyrolysis solid (PS) and pyrolysis gas (PG) during pyrolysis procedure to research the difference between in-situ and ex-situ catalytic pyrolysis. The gas chromatography-mass spectrometry (GC-MS) results show that CaO was conducive to the synthesis of aromatics, which content more than aliphatics and heterocyclics in CaO-i (i: in-situ) and CaO-e (e: ex-situ) groups. However, char greatly inhibits the production of aromatic compounds and promotes the production of aliphatic compounds. Gas chromatography (GC) results present that the char and CaO can greatly increase the content of combustible gas and the content reach to 85.85%, the pyrolysis gas (PG) keep at the highest combustion performance in char-CaO-i group. Meanwhile, compared with uncatalyzed groups, the content of CH 4 and CO increased about 2.05% and 3.93%, respectively. Fourier transform infrared spectroscopy (FT-IR) show that char and CaO reduce the function groups number of pyrolysis solid (PS), and it shows that the pyrolysis reaction is more complete. This research is expecting to provide theory support for catalytic pyrolysis of OS.
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高影响因子
Asia-Pacific Journal of Chemical Engineering
·
2021
·Vol. 16
·期 3
·e2609
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IF 1.447
Siliang Gao,Wencheng Tang,Ming Zhao,Siyuan Qie,Weiwei Pang,Longsheng Tian
Highly efficient separation of benzene, toluene, and xylenes (BTXs) from pyrolysis gasoline is very important in petrochemical industries. Though the extractive distillation (ED) process is simpler and consumes less energy compared with liquid–liquid extraction process, it is difficult for a single solvent, for example, sulfolane, to achieve both high purity and high yield of BTXs. In this work, methylsulfonylethane (MSE) was chosen as a cosolvent to improve the selectivity of sulfolane after solvent screening, and factors that may affect the selectivity of the composite solvent were fully investigated, such as the content of cosolvent, solvent to feed ratio, the composition of the feed, and temperature. Furthermore, 240 h of continuous extractive distillation and solvent recovery experiment was carried out using sulfolane (85 wt%)–MES (15 wt%) mixture as solvent. The purity of mixed aromatics obtained was 99.83%, and the yield was as high as 99.7%.
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Applied Sciences-Basel
·
2020
·Vol. 10
·期 21
·7607
·
IF 2.474
Yizhi Liu,Xu Liu,Ping Hu
A novel approach was proposed to increase the compactness, shorten the preparation period, and reduce the preparation cost by introducing acetone to optimize the polycarbosilane impregnation process. The porosity in internally derived SiC ceramics decreased and pore size was limited by using this new method, which led to higher compactness. Meanwhile, with the increase in acetone content, the viscosities of polycarbosilane and the wetting angles of polycarbosilane/graphite decreased appreciably, and the viscosity was 6.0 mPa·s with 40 wt.% acetone added—a factor of about 30 lower than that of original polycarbosilane. The wetting angle between polycarbosilane and graphite significantly decreased by 40%, which resulted in an enhancement in the impregnation efficiency of liquid polycarbosilane and a much shorter preparation period. This work provides a convenient and efficient method that is assistant during the practical production process of carbon fiber reinforced ceramic matrix composites (CMCs).Keywords:polycarbosilane;acetone;viscosity;wettability;impregnation efficiency
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CHEMICAL ENGINEERING JOURNAL
·
2020
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IF 10.652
Hang Yang,Siyu Huang,Yi Zhang,Boxun Zhou,Sanjrani Manzoor Ahmed,Huamin Liu,Yaowen Liu,Yong He,Shibin Xia
In this study, secondary pyrolysis oil-based drilling cuttings ash (OBDCA-sp) was used to remediate chromium (Cr)-contaminated soil. The effects of the OBCDA-sp mesh, OBCDA-sp dosage and soil moisture content on the removal of Cr (VI) were investigated. Subsequently, a kinetic experiment was conducted where the pseudo-first-order and pseudo-second-order kinetic models both fitted well on OBDCA-sp with the adsorption process of Cr (VI) in soil. The change of the chromium form indicated that the addition of OBCDA-sp transformed Cr from an effective state to a stable form, reducing its mobility and bioavailability . X-ray diffraction and Fourier transform infrared spectroscopy analysis were used to verify the potential mechanism of Cr (VI) removal; Ba, Fe, S, and P elements in OBCDA-sp were observed to play a significant role in the reduction of Cr (VI). The results from this study indicate that OBCDA-sp could be an emergent and promising alternative for the remediation of Cr-contaminated soil.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Jian Wang,Fang Feng,Chang Wang,Wei-Cheng Yan,Weidong Shi
Ultrasonic atomization pyrolysis (UAP) is an effective method for the mass production of micro-/nano-photocatalysts; however, studies on particle-flow behaviors and the collection efficiency were seldom reported, which are very important for its scale-up and industrialization. In this study, a computational fluid dynamics model was developed to simulate the UAP process. Experiments were carried out via a self-designed UAP setup to validate the developed model. A two-way coupling discrete phase model considering particle collision and breakage was employed to investigate the influence of operating conditions (for example, carrying gas flow rate, precursor concentration, ultrasonic frequency, particle injection rate, and temperature) on the collection efficiency and particle-flow behaviors. Effects of particle polydispersity were also studied based on the developed model. Finally, three types of UAP reactors were designed based on the developed model, and the results suggested that a T-shape reactor possessed higher particle collection efficiency. This study could help to understand the particle-flow behaviors inside the reactor, and the developed model could serve as a tool to optimize the design and operation of the UAP reactor toward large-scale production of photocatalysts.
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高影响因子
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