Simplification of Carbon Bond Mechanism IV (CBM-IV) under Different Initial Conditions by Using Concentration Sensitivity Analysis

• Main Authors: Le Cao, Simeng Li, Ziwei Yi, Mengmeng Gao
• Format: Article
• Language: English
• Published: MDPI AG 2019-07-01
• Series: Molecules
• Subjects: CBM-IV; mechanism simplification; concentration sensitivity analysis
• Online Access: https://www.mdpi.com/1420-3049/24/13/2463

Carbon Bond Mechanism IV (CBM-IV) is a widely used reaction mechanism in which VOCs are grouped according to the molecular structure. In the present study, we applied a sensitivity analysis on the CBM-IV mechanism to clarify the importance of each reaction under two different initial conditions (urban and low-NO_x scenarios). The reactions that exert minor influence on the reaction system are then screened out from the mechanism, so that a reduced version of the CBM-IV mechanism under specific initial conditions can be obtained. We found that in a typical urban condition, 11 reactions can be removed from the original CBM-IV mechanism, and the deviation is less than 5% between the results using the original CBM-IV mechanism and the reduced mechanism. Moreover, in a low-NO_x initial condition, two more reactions, both of which are nitrogen-associated reactions, can be screened out from the reaction mechanism, while the accuracy of the simulation is still maintained. It is estimated that the reduction of the CBM-IV mechanism can save 11−14% of the computing time in the calculation of the chemistry in a box model simulation.