Formation of Polycyclic Aromatic Hydrocarbons, Benzofuran, and Dibenzofuran in Fuel-rich Oxidation of Toluene Using a Flow Reactor

Author(s):  
Shunsuke Suzuki ◽  
Shota Kiuchi ◽  
Koichi Kinoshita ◽  
Yoshinaka Takeda ◽  
Satoshi Sakaida ◽  
...  

Recently, polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs) have been attracting considerable attention owing to their high toxicity. Understanding their formation mechanism during combustion processes is important to control...

2019 ◽  
Vol 121 (12) ◽  
pp. 3193-3207
Author(s):  
Congcong Liu ◽  
Chong Wang ◽  
Keping Ye ◽  
Yun Bai ◽  
Xiaobo Yu ◽  
...  

Purpose The purpose of this paper is to elucidate the influences of the animal fat and fatty acid type on the formation of polycyclic aromatic hydrocarbons (PAHs) and to propose a formation mechanism of PAHs in fat during electric roasting, which is a method of non-direct-contact-flame heating. Design/methodology/approach The effects of animal fats and model fat on the formation of PAHs were valued on the basis of the ultra high-performance liquid chromatography data. The corresponding products of the FAME pyrolysis were detected by TG-FTIR. The proposal formation mechanism of PAHs was based on the summary of the literature. Findings Contrary to the International Agency for Research on Cancer, DF had higher risk with 280.53 ng/g of concentration after being roasted than the others animal fats of red meat in terms of PAHs formation. This research also ensured the importance of fat on PAHs formation, the concentration of PAHs in pure fats was higher after being electric roasted than that in meat patties and juice which made from corresponding animal fat. What is more, during pure animal fats and meat products being processed, less PAHs formed in the fat with lower extent of unsaturation and lower content of linolenate. In the same way, methyl linolenate demonstrated the significant increasement to PAHs formation compared to the other fatty acids. And, the number of carbon atom and the extent of unsaturation in fatty acid affects the formation of PAHs during roasting. The detection of alkene and alkane allows to propose a formation mechanism of PAHs during model fat being heated. Further study is required to elucidate the confirm moleculars during the formation of PAHs. Originality/value This work studied the effect of the carbon atom number and the unsaturation extent of fats and model fats on the formation of PAHs. This work also assure the important of alkene and alkane on the pyrolysis of model fats. This study also researched the formation and distribution of PAHs in pure fats and meat products after being heated.


2014 ◽  
Vol 473-474 ◽  
pp. 317-325 ◽  
Author(s):  
Wolfgang Wilcke ◽  
Benjamin A. Musa Bandowe ◽  
Maria Gomez Lueso ◽  
Marc Ruppenthal ◽  
Hector del Valle ◽  
...  

2011 ◽  
Vol 15 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Jelena Radonic ◽  
Dubravko Culibrk ◽  
Mirjana Vojinovic-Miloradov ◽  
Branislav Kukic ◽  
Maja Turk-Sekulic

During the thermal combustion processes of carbon-enriched organic compounds, emission of polycyclic aromatic hydrocarbons into ambient air occurs. Previous studies of atmospheric distribution of polycyclic aromatic hydrocarbons showed low correlation between the experimental values and Junge-Pankow theoretical adsorption model, suggesting that other approaches should be used to describe the partitioning phenomena. The paper evaluates the applicability of multivariate piece-wise-linear M5? model-tree models to the problem of gas-particle partitioning. Experimental values of particle-associated fraction, obtained for 129 ambient air samples collected at 24 background, urban and industrial sites, were compared to the prediction results obtained using M5? and the Junge-Pankow model. The M5? approach proposed and models learned are able to achieve good correlation (correlation coefficient >0.9) for some low-molecular-weight compounds, when the target is to predict the concentration of gas phase based on the particle-associated phase. When converted to particle-bound fraction values, the results, for selected compounds, are superior to those obtained by Junge-Pankow model by several orders of magnitude, in terms of the prediction error.


2019 ◽  
Vol 102 (6) ◽  
pp. 1884-1891
Author(s):  
Chong Teng ◽  
Shimin Wu ◽  
Yaqing Sun ◽  
Guangyi Gong

Background: Polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs) are classes of contaminants that are present in the environment and food. They pose a great threat to human health because of their carcinogenicity and mutagenicity. Very few studies have focused on their concentration in waste cooking oil (WCO) and oil deodorizer distillate (ODD). Objective: This study aimed (1) to design a reliable method to determine 16 PAHs and 4 OPAHs in both WCO and ODD and (2) to determine and analyze PAH and OPAH concentrations in actual samples to provide references for further research. Method: The PAH determination approach included double liquid–liquid extraction, double solid-phase extraction, and GC–triple quadrupole tandem MS determination. Oxidation indices were determined by titrimetry. Results: The method reached good linearity (R2 > 0.99) and an acceptable recovery rate (55.01–126.16% for WCO and 57.48–128.97% for ODD). Ten WCO and five ODD samples were determined, and the total concentration of 16 PAHs varied from 16.34 to 239.01 and 101.08 to 198.04 μg/kg in WCO and ODD, respectively. Among the 16 PAHs, three-ring PAHs typically contributed the most. It was also found that the acid value has a strong correlation with the concentration of OPAHs, probably because of the contribution of free fatty acids to OPAH formation. Conclusions: The proposed method was effective in the analysis of PAHs and OPAHs in WCO and ODD.


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