Arabian Journal of Chemistry
·
2023
·
IF 6
Haijun Cheng,Min Liang,Suyi Dai,Xianrui Lu,Qilin Huang,Fang Lai,Li Ma,Weiguang Li,Xiongmin Liu
α-Pinene, β-pinene and turpentine are renewable resources that are widely used in fine chemicals, fuels and other applications, and the safety of their production, transport and use should be considered. In this work, the characteristics and hazardous of the oxidation process of α-pinene, β-pinene and turpentine were investigated by using a novel mini closed pressure vessel testing system (MCPVT). The oxidation products were resolved by gas chromatography-mass spectrometry (GC–MS). The results showed that α-pinene, β-pinene and turpentine were stable under nitrogen atmosphere and very active chemically under oxygen atmosphere. The activation energies ( E a ) of α-pinene, β-pinene and turpentine were calculated to be 78.87, 109.69 and 98.82 kJ/mol, respectively, using pressure–time (P-t) curves. So, the reaction activity sequence was α-pinene > turpentine > β-pinene. The peroxide concentrations of α-pinene (363 K), β-pinene (358 K) and turpentine (363 K) could reach 81.94, 84.70 and 75.76 mmol/kg, respectively, at relatively low temperatures. 0.6 g of α-pinene exploded at a system temperature of 369 K and an oxygen pressure of 1.23 MPa. 0.6 g of β-pinene also exploded at a system temperature of 373 K and an oxygen pressure of 1.27 MPa. 0.4 g of turpentine experienced thermal runaway at a system temperature of 384 K and an oxygen pressure of 0.81 MPa. The major oxidation products of α-pinene are α-campholenaldehyde, laevo-pinocarveol, verbenol, verbenone, bicyclo (3.1.1)heptane-2, 3-diol, 2, 6, 6-trimethyl, 2-cyclohexen-1-ol, 2-methyl-5-(1-methylethenyl)-, (1R,5R)-rel-, cyclobutaneacetic acid, 3-acetyl-2, 2-dimethyl, myrtenol and myrtenal. The major thermal runaway products are water, ethanol, acetone, acetic acid, 2-pentanone, propyl acetate, toluene, cymene and methylacetophenone. The major oxidation products of β-pinene are nopinone, laevo-pinocarveol, pinocarvone, myrtenol, myrtenal and perillyl alcohol. The major thermal runaway products are water, ethanol, acetone, n-ethyl propanoate, toluene, butyl acetate, cymene, apocamphor, nopinone, bornyl formate, methylacetophenone and dihydronopol. The oxidation products and thermal runaway products of pinene were significantly different. Possible reaction pathways for α-pinene and β-pinene are proposed.
研究领域:
化学工程
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安全科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 32
·19124-19133
·
IF 3.119
Chang Yu,Yuan-Lin Li,Min Liang,Su-Yi Dai,Li Ma,Wei-Guang Li,Fang Lai,Xiong-Min Liu
Pressure and temperature behavior of the cinnamaldehyde oxidation process was determined using a custom-designed mini closed pressure vessel test (MCPVT), which is a new method to investigate the stability and hazard assesment of the cinnamaldehyde oxidation reaction. The oxidation products were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that cinnamaldehyde was stable under nitrogen atmosphere but very unstable under oxygen atmosphere. The initial oxidation products were analyzed by iodimetry and the cinnamaldehyde peroxide value could reach 139.44 mmol kg−1 when the oxidation temperature was 308 K. The oxidation kinetics of cinnamaldehyde were studied by using the pressure versus time (P–t) curves obtained from the MCPVT process. The reaction is a second-order reaction, the kinetic equation is ln k = −2233.66 × (1/T) + 11.19, and the activation energy Ea is 18.57 kJ mol−1 at 308–338 K. The explosion of the cinnamaldehyde oxidation reaction was observed by MCPVT, in which the onset temperature was 373 K. The main products of cinnamaldehyde oxidation are acetaldehyde, benzaldehyde, phenylacetaldehyde, acetophenone, 2-hydroxyphenyl acetone, cinnamaldehyde epoxide, benzoic acid, and cinnamic acid. Oxidation is a three-step process: (1) cinnamaldehyde reacts with oxygen to form peroxides; (2) complex oxidation reactions are caused by the thermal decomposition of peroxides; (3) rapid oxidation and thermal decomposition lead to explosion hazard.
研究领域:
化学工程
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安全科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2021
·
IF 6.158
Xiao-Qiao Zhao,Wen-Qian Wu,Hua-bo Li,Zi-Chao Guo,Wang-Hua Chen,Li-Ping Chen
As a self-reactive substance, benzaldehyde oxime (BO) is prone to a highly exothermic runaway reaction and thermal hazard analysis and the reaction kinetics calculation of BO have great significance. In this work, the decomposition products of BO in nitrogen atmosphere were identified by GC–MS and HPLC techniques. The impact of the decomposition products on the decomposition behaviors of BO were analyzed by comparison of the ARC test results of pure BO and mixture of BO and decomposition products. It was found that N-benzylidene benzylamine was the intermediate decomposition product and benzoic acid , benzamide, N-benzyl benzamide, and 2,4,5-triphenylimidazole were the final products of BO. A two-step continuous autocatalytic reaction model was established to depict the decomposition process of BO. The kinetic parameters of the model were calculated by applying the nonlinear optimization method. Finally, thermal behaviors under different process temperature were predicted based on the kinetic model , and the time to maximum rate (TMR ad ) was predicted as 112.04 °C under 24 h, and 122.19 °C of 8 h, which offer crucial safety information to optimize the safety conditions of BO during usage, storage and transportation, which minimizes the industrial disasters.
研究领域:
化学工程
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安全科学
✓ 已验证
DOI
高影响因子
FIRE AND MATERIALS
·
2018
·Vol. 42
·期 7
·805-815
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IF 1.22
Qinpei Chen,Yaping He,Xuehui Wang,Tiannian Zhou,Chao Ding,Jian Wang
Summary To study the low pressure influence on the flash point and fire hazard of organic fuels and their aqueous solutions, a series of experiments has been conducted to measure the open-cup and closed-cup flash points of methanol, ethanol, and n -decane aqueous solutions including different mole fractions under different static pressures ranging from 35 to 101 kPa. The results show that both the pressure and fuel mole fraction have a nonlinear correlation with the flash point of the miscible fuel specimens like the correlation provided in this paper. For the partially miscible fuel specimens with a lower density than water, the water content has almost no influence on the flash point. The fire risks of the experimental results were analysed based on the standard GB50160-2008, which shows that the fire risk becomes higher at low pressures, and there is a critical pressure at the turning point of the change in fire classification. A method to achieve the critical low pressure of different fuels or aqueous solutions from the fire hazard classification is derived in this paper.
研究领域:
化学工程
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安全科学
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2020
·Vol. 67
·期 1
·e17089
·
IF 3.519
Wei Jiang,Lei Ni,Juncheng Jiang,Qiang Chen,Zhiquan Chen,Shuliang Ye
In this study, various calorimetric and analytical techniques were used to evaluate the thermodynamics of the preparation of adipic acid through the oxidation with hydrogen peroxide. The reaction exotherm was combined with the reaction mechanism. Differential scanning calorimetry revealed that the hydrogen peroxide was relatively stable when Na 2 WO 4 .2H 2 O and H 2 SO 4 were used as cocatalysts. Reaction calorimetry, in situ Fourier transform infrared spectroscopy and gas chromatography/mass spectrometry (GC/MS) results indicated a possible macroscopic reaction pathway at 73 and 90°C stage. Furthermore, the results obtained through adiabatic calorimeter (Phi-TEC II) and GC/MS indicated the possibility of catastrophic accidents if control of the target reaction was lost. The criticality classes of this reaction were of Grade 5. The results of this study can be further used to improve the inherent safety of its operating measures, as a result, this reaction process can be scaled up.
研究领域:
化学工程
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安全科学
·
分析化学
✓ 已验证
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2024
·
IF 12.7
Bin Zou,Ziyan Qian,Zixuan Zhang,Weiyi Xing,Shangshang Zhong,Jiajun Li,Fukai Chu,Yongchun Kan,Jie Chen,Yuan Hu
Fire hazards are a primary concern in aircraft accidents, and controlling combustible materials is pivotal in managing cabin fire risks. This work aims to elucidate the impact of widespread measures that introduce phosphorus-based flame retardants (PFRs) on the fire safety of carbon fiber epoxy composites (CF/EP). Firstly, the hazardous indicators for flame retardant CF/EP composites exhibit two categories of optimization and degradation, which are caused by the intrinsic feature, pyrolysis characteristics and chemical valence states of PFRs. Secondly, the fire hazards of composites are assessed by fusing the analytic network process and information weights guided by Nash Equilibrium theory. The method combines the merits of subjective and objective weights from dimensions of intrinsic hazards, interrelationships and data dispersion of indicators. Finally, the assessed fire hazard rankings under 35 and 65 kW/m 2 both are EP > CF/EP16%DOPO-HQ > CF/EP > CF/EP7%DPO. In conclusion, DOPO-HQ (+1) primarily increases the fire hazard of CF/EP due to gas-phase flame-retardant effects, while DPO (+3) predominantly reduces the fire hazard of CF/EP by contributing to condensed-phase effects. This work highlights the contradictory effects of PFRs on the fire safety of CF/EP composites due to structure and thermal stability. The proposed ANP and IW hybridization method provides a theoretical foundation for selecting flame retardants and assessing material fire hazards comprehensively.
研究领域:
航空工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2021
·Vol. 147
·期 2
·1389-1404
·
IF 4.626
Wu Wen-qian,Dong Ze,Xue Bei-bei,Guo Zi-chao,Chen Li-ping,Wang Shun-yao,Li Hua-bo,Chen Wang-hua
Thermal runaway of chemical reactions often lead to secondary decomposition of the material, especially with autocatalytic decomposition characteristics. Autocatalytic decompositions are often characterized by drastic decomposition, intense heat release, high thermal risk and difficultly in control. Quantitative classification of different autocatalytic strengths is significant for the formulation of risk control measures and recognition of the most dangerous scenarios in relief system. In this work, the factor, which is the ratio of the heat released by the initial stage to that of the total reaction, has been defined to effectively and quantitatively assess the strength of autocatalytic decomposition based on the Perez-Benito model that includes two-stage competitive reactions. According to “3σ principle” of the normal distribution, the factor was classified into five grades: 0–5%, 5–18%, 18–82% 82–95%, 95–100% corresponding to the autocatalytic strength: strong, less strong, moderate, less weak and weak, respectively. This method is validated using cumyl hydro-peroxide and dicumyl peroxide, the autocatalytic strength of which are well known to be less strong (7.92%) and weak (100%), respectively. The results are consistent with the profile width, heat-quench-reheat test and the isothermal tests. This method was used to classify the autocatalytic strength of dimethyl sulfoxide, 29.5 mass% nitro-guanidine aqueous solution, and Benz aldoxime. The results show that the autocatalytic strengths of these three materials are strong (0.01%), moderate (31.52%) and less weak (82.67%), respectively. Through the classification assessment, it helps to get a more intuitive understanding of the degree of substance danger from the perspective of kinetics and thermodynamics.
研究领域:
化学工程
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安全科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2016
·
IF 4.836
Qi Sun,Lin Jiang,Liang Gong,Jin-Hua Sun
During PUREX spent nuclear fuel reprocessing, mixture of tributyl phosphate (TBP) and hydrocarbon solvent are employed as organic solvent to extract uranium in consideration of radiation contaminated safety and resource recycling, meanwhile nitric acid is utilized to dissolve the spent fuel into small pieces. However, once TBP contacts with nitric acid or nitrates above 130 °C, a heavy “red oil” layer would occur accompanied by thermal runaway reactions, even caused several nuclear safety accident. Considering nitric acid volatility and weak exothermic detection, C80 micro calorimeter technique was used in this study to investigate thermal decomposition of TBP mixed with nitric acid. Results show that the concentration of nitric acid greatly influences thermal hazard of the system by direct reactions. Even with a low heating rate, if the concentration of nitric acid increases due to evaporation of water or improper operations, thermal runaway in the closed system could start at a low temperature.
研究领域:
化学工程
·
核能安全
·
热分析
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Case Studies in Thermal Engineering
·
2023
·
IF 6.8
Haijun Cheng,Haoping Chen,Qilin Huang,Qiaoni Luo,Min Liang,Suyi Dai,Fang Lai,Li Ma,Weiguang Li,Xiongmin Liu
Although pinane has a wide range of uses, there are no reports on the safety of pinane oxidation. The thermal oxidation properties of pinane were investigated through MCPVT. The primary oxidation products of pinane were separated and structurally characterised, and its decomposition properties were assessed by MCPVT and DSC. The results showed that pinane had an initial oxygen uptake temperature of 123.5 °C and exploded when the temperature rose to 132.7 °C. Pinane autoxidised at 110 °C for 9 h formed a high level of peroxide (81.18 mmol/kg) with an activation energy of 138.77 kJ/mol. The oxidation of pinane occurs mainly at the tertiary carbon atom attached to the methyl group, and the main peroxide produced is pinane hydroperoxide (PHP). PHP has an exothermic onset temperature (T onset ), a heat of decomposition (Q DSC ) and an activation energy of decomposition of 114.6 °C, 1878.0 J/g and 109.4 kJ/mol respectively, which should classify it as a hazardous substance. PHP has a lower activation energy than pinane and is the determining factor for the safety of the pinane oxidation reaction. The products of thermal runaway of pinane are relatively complex and consist mainly of 1-(2, 2-dimethyl-3-ethylcyclobutyl) ethanone, nopinone, 2, 3-pinanediol and pinonic acid.
研究领域:
化学
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安全科学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2018
·
IF 2.189
Jun-Cheng Jiang,Li Li,Jia-Jia Jiang,Yan Wang,Siu-Ming Lo,Yong Pan,Xu-Hai Pan,Lei Ni
Tert-butyl peroxybenzoate (TBPB) is thermally unstable organic peroxide, which may cause disasters such as fire or explosion when excessive heat released due to thermal decomposition. Ionic liquid is often used as a catalyst and inhibitor in engineering applications recently. This study investigated the thermal decomposition characteristics of TBPB when added two different ionic liquids which are 1-Propyl-3-methylimidazolium iodide ([PMIM][I]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) respectively with different mass ratio under DSC tests. Characteristic parameters such as the onset exothermic temperature (T 0 ) and heat of decomposition (ΔH d ) of samples were compared. Kinetic parameters such as activation energy E a were computed using two isoconversional methods which were Ozawa method and Friedman method respectively. The model based (zeroth order reaction) estimation method was used to estimate TMR ad at T 0 from non-isothermal DSC measurements to assess the thermal hazard of five samples. The paper aims to study the effect of ionic liquids (ILs) on the thermal decomposition of TBPB and analysis the influence of two ionic liquids on the decomposition mechanism of TBPB.
研究领域:
化学工程
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安全科学
✓ 已验证
DOI
高影响因子
Sustainability
·
2023
·Vol. 15
·期 8
·6530
·
IF 3.9
Yinshan Liu,Lei Ni,Hang Yao,Jimi Su,Zhen Cheng
The synthesis of adipic acid, which is formed by the reaction of cyclohexene oxidized by hydrogen peroxide (H2O2), is hazardous because of the highly exothermic nature of this reaction and H2O2decomposition. The objective of this comprehensive study was to investigate and illustrate the effects of sulfuric acid (H2SO4) and H2O2stabilizer (EDTA) on the thermal hazard of H2O2decomposition and the green synthesis of adipic acid, which also provided a reference to reduce the risk of the reactions. Various calorimetry techniques were carried out to characterize the exothermic behavior of the reactions. An HPLC device was used to characterize the yield of adipic acid and the conversion rate of the raw materials, cyclohexene and H2O2. Meanwhile, density functional theory calculations were performed to understand the reaction mechanism and the associated energies of H2O2decomposition catalyzed by sodium tungstate dihydrate (Na2WO4·2H2O). Finally, combined with the calorimetry results, the risk of the adipic acid synthesis reaction was assessed using the intrinsic control index method (ITHI). The results show that the addition of H2SO4and EDTA can reduce the exothermic heat of the H2O2decomposition reaction and the green synthesis reaction of adipic acid. The yield of adipic acid was also increased. The hazard level of stage A was IV, and to remove more reaction heat, it was recommended to enhance the reflux cooling of stage A. The hazard level of stage B was I, which was very low and no further measures could be taken.Keywords:adipic acid;hydrogen peroxide decomposition reaction;hydrogen peroxide stabilizer;thermal hazard assessment
研究领域:
化学工程
·
安全科学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2013
·
IF 1.989
N. Zang,X.M. Qian,P. Huang,C.M. Shu
Cyclohexanone peroxide (CYHPO) is widely used in the chemical industry, but unfortunately, as an organic peroxide, it has been involved in many serious fires and explosions in daily manufacturing, storage, and transportation. We present an advanced methodology of application of thermal analysis for thermal hazard investigation of complex chemical reactions. The applied method is based on a differential isoconversional approach and involves the combination of non-isothermal differential scanning calorimetry (DSC) and adiabatic measurements by accelerating rate calorimeter (ARC) for kinetic analysis and prediction. The kinetic parameters and heat balance were analyzed and used for a simulation of the adiabatic behavior: time to maximum rate under adiabatic conditions ( TMR ad ) and self-accelerating decomposition temperature ( SADT ). Applications of finite element analysis (FEA) for heat balance and accurate kinetic description allowed us to determine the effect of scale, geometry, heat transfer, thermal conductivity, and ambient temperature on the heat accumulation process. The presented explosion simulations of the thermal behavior of 100 kg storage tank at different temperatures, related to the possible storage scenarios, may help in the elucidation of a real accident which occurred in Beijing during CYHPO storage.
研究领域:
化学工程
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安全科学
·
热分析
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）