SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Gang Chu,Wangmin Wang,Jing Zhao,Dandan Zhou
Phosphoric acid-assisted pyrolysis (PAAP) is a pyrolysis technique with potential for the engineered and environmental application. Nevertheless, the volatilisation, immobilisation, and dissolution of phosphorus (P) species have been neglected during PAAP of lignocellulose. Therefore, we compared the transformation of P species with direct-pyrolysis and PAAP system, using multiple techniques including gas chromatography tandem mass spectrometry (GCMS) and 31 P nuclear magnetic resonance (NMR). It was also investigated that the properties of pyrogenic and modified carbons obtained from lignocellulose pyrolysis at 200–650 °C. As the temperature increased, volatile P species evolved into gas-phase during PAAP, inhibiting the formation of the macromolecular volatile components. Compared with pyrogenic carbons, modified carbons with more aromatic structures experienced a higher degree of dehydration and cyclisation via catalytic crosslinking reaction. PAAP system facilitated more generation of persistent free radical (PFR) below 500 °C and the attenuation of PFR signals was observed at 500–650 °C, which may be associated with the sequestration and elimination of P species between carbon matrix. Notably, three configurations of C 3 P O, C P O, and C O P were the major combinations of P and C elements on modified carbons. Increased gaseous P and decreased soluble P were observed with elevated temperatures in PAAP system. The species proportion of immobilised P clearly demonstrated the transformation of partial P species from inorganic to organic through pyrolysis. The immobilised P could serve as a potential sustained-release source participating in P biogeochemical cycles . These findings are fundamental for the technical design of lignocellulose pyrolysis.
研究领域:
环境科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2023
·Vol. 16
·期 6
·2362
·
IF 3.4
Kuntong Song,Yi Li,Ruiqi Zhang,Nan Wang,Junhong Liu,Wenxia Hou,Qing Zhou,Xingmei Lu
Compared with conventional pyrolysis, steam-assisted pyrolysis of polyethylene terephthalate (PET) can effectively eliminate char and upgrade terephthalic acid (TPA). However, during steam-assisted pyrolysis of PET, the degree of cracking still varies greatly, and while some of the product is excessively cracked to gas, the other part is still insufficiently cracked. In addition, these two types of products seriously affect the yield and purity of TPA. To further enhance the TPA, an attempt was made to reduce these impurities simultaneously by synergistic catalysis among the different components of the metal–acid catalyst. Through a series of experiments, Pt@Hzsm-5 was screened as the optimal catalyst. In the catalytic steam-assisted pyrolysis of PET, the optimum reaction temperature decreased to 400 °C, the calculated yield of TPA increased to 98.23 wt%, and the purity increased to 92.2%. The Pt@Hzsm-5 could be recycled three times with no significant decrease in the obtained yield of TPA. The catalytic mechanism of the Pt@Hzsm-5 was investigated through the analysis of the products and isotope tracing experiments. The Pt catalyzed the hydrogen transfer reaction between the water molecules and PET molecules, which inhibited the excessive cracking of TPA by improving the hydrogen transfer efficiency, reduced the generation of gaseous products, and improved the calculated yield of TPA. In contrast, the Hzsm-5 catalyzed the reaction of monovinyl ester cracking to TPA, effectively reducing the impurities in the solid product, increasing the olefin yield, and improving the purity of TPA. This discovery not only clarifies the synergistic catalytic effect of the Pt@Hzsm-5 in the steam-assisted pyrolysis of the PET reaction but also lays the foundation for further screening of other inexpensive metal–acid catalysts. This is of great significance to realize the industrial application of TPA preparation by PET pyrolysis.Keywords:PET;metal–acid catalyst;steam-assisted pyrolysis;TPA
研究领域:
化学工程
·
催化材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Thermal Science and Engineering Progress
·
2023
·
IF 4.8
Shuai Guo,Guoliang Qi,Jialiang Gao,Deng Zhao,Kaixin Chen,Chenchen Zhao,Xingcan Li,Guangyu Li
Pyrolysis is an effective method for safely disposing of sewage sludge via conversion into a usable energy source. However, municipal sludge has a high protein content, which is a major source of NO x precursors. This study investigated the effect of CaO on NO x precursor formation during glutamate pyrolysis and demonstrated that CaO occupies the carbo x yl site of glutamic acid at 320 °C, which delays its decomposition and promotes the conversion of glutamic acid from a five- to a si x -membered ring. At 400 °C, heterocyclic nitrogen in the tar peaked from 4.87 to 53.87% after adding CaO. As the temperature increases to 480 °C, CaO might promote the conversion of heterocyclic nitrogen into tricyclic piperazine dione in the tar, which subsequently decomposed to produce HCN in large quantities. At 480 °C, CaO contributed to the decrease in pyrrole, pyridine, and quaternary nitrogen in the semi-coke from 24.81%, 12.93%, and 7.43% to 1.91%, 5.97%, and 1.43%, respectively and promoted HCN hydrolysis to form NH 3 . At 480–680 °C, CaO interacted with NH 3 to form CaCN 2 . The product of CaC x N y decomposition—CaC x —captured NH 3 . At high temperatures, CaO inhibited HCN release, which might be related to the reaction between CaO and HCN to form CaC x N y , subsequently reconverted into CaO at temperatures above 680 °C. These findings provide novel insights into the influence of CaO on amino acid pyrolysis to produce NO x precursors and the regulation of NO x precursor production.
研究领域:
环境科学
·
能源与燃料
✓ 已验证
产品关联
DOI
高影响因子
WASTE MANAGEMENT
·
2023
·
IF 8.1
Yang Ren,Hongyun Hu,Chengyang Cao,Guangzhao Guo,Xiaodong Zeng,Chan Zou,Xian Li,Hong Yao
Disposal of automobile shredder residue (ASR) via pyrolysis enables the recovery of valuable products; however, the production of hazardous pollutants and low-value products is inevitable due to its high chlorine content. In this work, chlorine evolution behavior and the conversion mechanism during ASR pyrolysis between 480 and 600 °C were systematically studied. The experimental results for organic chlorine (Org-Cl) showed that released chlorinated gases were complex, and HCl only accounted for 35% of the gas phase products, while short-chain hydrocarbons with carbon atoms between two and four accounted for 52%. Chlorine was predominantly retained in the char, and Org-Cl was the primary contributor to the residual chlorine, accounting for over 50% of the char. The content of inorganic chlorine (InO-Cl) was low in the raw sample but significantly increased in the char. Through the distinction between organic and inorganic chlorine content in char, it was confirmed that Org-Cl could be converted to InO-Cl due to complex secondary reactions with metallic compounds. The conversion was favored by increasing the Org-Cl content and the temperature. Our findings clarified the evolution mechanism of chlorine and the transformation from Org-Cl to InO-Cl, thus providing guidance for chlorine regulation and the efficient recycling of metal resources.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMBUSTION AND FLAME
·
2024
·
IF 5.8
Jinzeng Pan,Jinyu Tan,Shiling Wei,Shuyao Chen,Haikun Lang,Fangping Bin,Zhandong Wang,Lixia Wei
Isomers of alkanes have a significant effect on their combustion performance. In order to better understand the effect of the number of methyl side chains on fuel performance, the pyrolysis experiments of 2,3-dimethylhexane (C 8 H 18 –23) were carried out by using a jet-stirred reactor and the synchrotron vacuum ultraviolet photoionization mass spectrometry at 770 - 1130 K and at atmospheric pressure. Key pyrolysis products, such as acetylene, ethylene, propene, 1,3-butadiene, 2-butene, 1-pentene, 2-methyl-2-butene, 2-methyl-2-hexene, 3-methyl-2-hexene, as well as benzene, styrene and naphthalene, etc., were identified and measured. A detailed kinetic model of C 8 H 18 –23 pyrolysis, including 1756 species and 6023 reactions, was constructed and validated against the experimental results in the present work. Rate of production and sensitivity analysis of C 8 H 18 –23 showed that the major consumption pathways are H-abstractions and unimolecular dissociation reactions, with the highest contributions from those at/between C(2) and C(3) atoms. Theoretical comparison of the pyrolysis of the three isomers of C 8 H 18 hydrocarbon, i.e., C 8 H 18 –23, 2-methylheptane and n- octane, shows that with increasing of the number of methyl side chains, C 8 H 18 will be more reactive in pyrolysis and be more effective in producing soot precursors.
研究领域:
化学工程
·
燃料化学
·
燃烧科学
✓ 已验证
DOI
高影响因子
ENERGY
·
2024
·
IF 9
Deshi Yang,Jianpeng Huang,Zhipeng Hu,Shiqi Qin,Jiaxin Mu,Fengqiang Wang,Zhijun Zhang,Yanjun Xie,Shouxin Liu,Qingwen Wang
Catalytic fast pyrolysis (CFP) of lignin aiming monocyclic aromatic hydrocarbons (MAHs) is attractive. Five metal oxide catalysts (named c-Nb 3 Al x ) with different Nb/Al ratios, c-Nb, c-Al, c-Nb 3 Al 1 , c-Nb 3 Al 2 and c-Nb 3 Al 3 were synthesized and applied to CFP of lignin. Among these catalysts, c-Nb 3 Al 2 exhibits excellent deoxygenation ability and the highest selectivity for MAHs (77.0 %). The selectivity and deoxygenation capacity of c-Nb 3 Al 2 for MAHs were higher than H-ZSM-5 (25) as a control. It was attributed to the large external surface area (90 m 2 g -1 ), mesoporous structure (16.15 nm) and high acid amount (2.00 mmol NH 3 /g cat ) of c-Nb 3 Al 2 . The c-Nb 3 Al 2 has good stability and can be regenerated by simple calcination . The selectivity of the regenerated c-Nb 3 Al 2 for MAHs was still high at 70.1 %. Guaiacol was used to compare the difference in the deoxygenation capacity of c-Nb 3 Al 2 and H-ZSM-5.
研究领域:
化学工程
·
材料科学
·
催化
·
生物能源
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PORPHYRINS AND PHTHALOCYANINES
·
2019
·Vol. 23
·期 09
·1013-1019
·
IF 1.292
Shen Shen,Zihui Zhai,Jiaqi Qin,Xue Zhang,Yujiang Song
The employment of inexpensive metallomacrocycles to create non-precious metal electrocatalysts (NPMEs) with high performance remains a challenge. Herein, we report the self-assembly of low-cost and abundant hemin on carbon black (EC600) under hydrothermal conditions in combination with subsequent pyrolysis, leading to a new NPME. Our NPME exhibits a half-wave potential of 0.89 V vs . reversible hydrogen electrode (RHE), an onset potential of 1.0 V vs . RHE and an average HO 2 − yield below 2% as well as high durability toward oxygen reduction reactions (ORR) in alkaline electrolytes, ranking at the top of all reported NPMEs derived from hemin.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Guozhang Chang,Peng Miao,Ximin Yan,Guijin Wang,Qingjie Guo
In the present study, the characteristics of phenol preparation from palm kernel shell (PKS) pyrolysis at the temperature range of 265–320 °C were investigated using TG-FTIR-MS analyses, based on the analysis about the decomposition characteristics of PKS comparing to other biomass samples. The GC–MS analysis was subsequently employed to qualitatively and quantitatively characterize the phenol in bio-oils from PKS catalytic pyrolysis at 265–320 °C. Two significant weight loss peaks with the closer values were observed in DTG curve of PKS that differentiated with other samples, which was mainly attributed to the content and especially the structural characteristics of lignin in the PKS. Phenol was mainly in bio-oils from decomposition of the “first weight loss peak” during PKS pyrolysis at 265–320 °C. The relative content in bio-oil, selectivity in phenolic compounds, and mass yield of phenol from PKS catalytic pyrolysis with CaO could reach to 83.21 area%, 100%, and 0.0075 g/(g biomass), respectively.
研究领域:
能源与燃料
·
生物质化学
✓ 已验证
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2014
·
IF 3.828
Huan Liu,Qiang Zhang,Hongyun Hu,Peng Liu,Xiaowei Hu,Aijun Li,Hong Yao
Thermal disposal of sewage sludge is likely to cause serious nitrogen related environmental pollution since it contains considerable amounts of nitrogen, the species of which are quite different from those in coal. Considering that lime (CaO) is a widely applied chemical conditioner for sewage sludge dewatering, this study investigated the catalytic role of conditioner CaO in nitrogen transformation during sewage sludge pyrolysis in a drop-tube/fixed-bed furnace at 873 K, 1073 K and 1273 K, respectively. Model compounds were also used to further clarify the mechanisms involved. According to the results, conditioner CaO increased the fraction of more stable protein-N as well as amine-N. The solid phase reactions produced CaC x N y , thus enhancing the nitrogen retention in char. Correspondingly, decreased relative ratio of nitrates-N/nitrites-N and oxygenated organics in sludge conditioning contributed to less NO emission. Meanwhile, conditioner CaO promoted the conversion of HCN to NH 3 , as well as the deamination of proteins, amine, and other N-containing compounds in tar and char, leading to increased NH 3 generation. Subsequently, CaC x , the decomposition product of CaC x N y , captured NH 3 , driving down the final production of NH 3 . In addition, Ca(OH) 2 hindered the transformation of nitrile-N in char to HCN, decreasing HCN generation. CaO reacted with HCN, further reducing its releasing amount. CaC x N y derived from different sources decomposed to produce a very large amount of N 2 . These indicate that reusing conditioner CaO is a promising strategy for reducing the productions of NO x precursors efficiently and increasing the formation of non-polluting N 2 dramatically.
研究领域:
环境科学
·
能源与燃料
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Chao Liu,Huiyan Zhang,Rui Xiao,Shubin Wu
Thermogravimetric characteristics of chitin and chitosan and their potentials to produce value-added organonitrogen chemicals were separately evaluated via TG/DSC-FTIR and Py-GC/MS. Results shown that chitin had the better thermal stability and higher activation energy than chitosan because of the abundant acetamido group. Furthermore, the dominated volatilization in active pyrolysis of chitin contributed to its endothermic property, whereas the charring in chitosan led to the exothermal. During fast pyrolysis, the acetamido group in chitin and chitosan was converted into acetic acid or acetamide. Typical products from chitosan pyrolysis were aza-heterocyclic chemicals, i.e. pyridines, pyrazines, and pyrroles, with the total selectivity of 50.50% at 600 °C. Herein, selectivity of pyrazine compounds was up to 22.99%. These aza-heterocyclic chemicals came from the nucleophilic addition reaction of primary amine and carbonyl. However, main reaction during chitin pyrolysis was ring-opening degradation, which led to the formation of acetamido chemicals, especially acetamido acetaldehyde with the highest selectivity of 27.27% at 450 °C. In summary, chitosan had the potential to produce aza-heterocyclic chemicals, and chitin to acetamido chemicals.
研究领域:
生物化学
·
材料科学
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
·
2025
·
IF 6.2
Shubao Song,Jiankun Shao,Lin Zhang,Jiachen Sun,Cheng Wang,Jun Yi,Zhiqiang Gao,Jianli Feng
Acetone (CH 3 COCH 3 ) is a key intermediate and a representative oxygenated volatile organic compound (OVOC) relevant to biofuels, atmospheric chemistry, and advanced propulsion systems. In the current study, shock tube pyrolysis experiments for acetone/Ar mixtures were performed over the temperature range of 1300–1952 K at atmospheric pressure, utilizing laser absorption diagnostics at 4854 nm and 3175 nm to monitor the temporal evolution of carbon monoxide (CO) and methane (CH 4 ), respectively. In addition, ignition delay time (IDT) measurements were conducted in a shock tube for CH 3 COCH 3 /Ar/O₂ mixtures at three equivalence ratios ( φ = 0.5, 1.0, and 2.0) over the temperature range of 1274–1601 K and 1.0 atm. The CO time-history data provided direct constraints on the unimolecular decomposition reaction R1 (CH 3 COCH 3 (+M)=>CH 3 CO + CH 3 (+M)), yielding a rate constant of k R1 (1304–1952 K, 1.0 atm) = 9.0 × 10 13 exp (−66,500 cal/mol/ RT ) s⁻¹, with an uncertainty of +28.7 %/−28.2 %. Additionally, CH 4 time-histories and IDTs measurements combined with sensitivity analysis were employed to refine the H-abstraction reactions R2 (CH 3 COCH 3 + CH 3 <=>CH 3 COCH 2 + CH 4 ) and R3 (CH 3 COCH 3 + H<=>CH 3 COCH 2 + H 2 ), respectively. A detailed kinetic model of acetone consisting of 41 species and 284 reactions was developed based on the FFCM-1 framework and optimized skeletal sub-model of acetone with updated rate constants of R1, R2 and R3. Validation against a wide range of literature data, including IDTs, laminar flame speeds and speciation data from literature, demonstrates the robustness and accuracy of the optimized kinetic model. This work highlights the critical role of laser-based diagnostics in resolving key elementary reactions and illustrates the advantages of compact, well-calibrated kinetic models for high-temperature acetone combustion research.
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Haifeng Jiang,Haipeng Liu,Baolin Liu,Yu Zhang,Shu Li,Jie Chen
This work studied the effect of cellulose–lignin interactions under potassium formate (HCOOK) and nickel formate (Ni(HCOO)2) on behavior and product distributions. The results indicated that the presence of HCOOK affected the whole thermal decomposition process, while the effect of Ni(HCOO)2 was mainly manifested before 339 °C. The interaction under the action of HCOOK favored the generation of carbonyl compounds, and the catalytic pyrolysis with Ni(HCOO)2 was better for formating phenols. The high peak intensities of CO and CH4 were achieved by adding nickel formate and potassium formate, respectively. It was obviously different from noncatalytic pyrolysis. The evolution of a char structure further revealed that different formate salts had different effects on the interactions. The statistical method according to the distribution of the liquid component confirmed that HCOOK had the strongest effect for reducing the cellulose–lignin interactions.
研究领域:
生物质能
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）