Open AccessMathematical Modeling and Mechanism of VUV Photodegradation of H2S in the Absence of O2
Author(s) -
Jianhui Xu,
Binbin Ding,
Xiaomei Lv,
Shanhong Lan,
Chaolin Li,
Peng Liu
Publication year - 2018
Publication title -
international journal of photoenergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.426
H-Index - 51
eISSN - 1687-529X
pISSN - 1110-662X
DOI - 10.1155/2018/2769213
Subject(s) - photodegradation , chemistry , degradation (telecommunications) , kinetics , photochemistry , photocatalysis , computer science , catalysis , physics , organic chemistry , telecommunications , quantum mechanics
The existence of H 2 S has limited the biogas energy promotion. The traditional photodegradation of H 2 S is usually conducted in the presence of O 2 , yet this is unsuitable for biogas desulfurization which should be avoided. Therefore, the ultraviolet degradation of H 2 S in the absence of O 2 was investigated for the first time in the present study from a mathematical point of view. Light wavelength and intensity applied were 185 nm and 2.16 × 10 −12 Einstein/cm 2 ·s, respectively. Firstly, the mathematical model of H 2 S photodegradation was established with MATLAB software, including the gas flow distribution model and radiation model of photoreactor, kinetics model, mass balance model, and calculation model of the degradation rate. Then, the influence of the initial H 2 S concentration and gas retention time on the photodegradation rate were studied, for verification of the mathematical model. Results indicated that the photodegradation rate decreased with the increase in initial H 2 S concentration, and the maximum photodegradation rate reached 62.8% under initial concentration of 3 mg/m 3 . In addition, the photodegradation rate of H 2 S increased with the increase in retention time. The experimental results were in good accordance with the modeling results, indicating the feasibility of the mathematical model to simulate the photodegradation of H 2 S. Finally, the intermediate products were simulated and results showed that the main photodegradation products were found to be H 2 and elemental S, and concentrations of the two main products were close and agreed well with the reaction stoichiometric coefficients. Moreover, the concentration of free radicals of H• and SH• was rather low.