Gao Mengjiao, He Jiuning, Tian Lilan, Chen Lei, Shi Shunping, Zhang Changhua, Chen Deliang
College of Mathematics and Physics, Chengdu University of Technology, Chengdu, Sichuan 610059, China.
Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.
J Phys Chem A. 2024 Apr 11;128(14):2825-2842. doi: 10.1021/acs.jpca.4c00794. Epub 2024 Apr 2.
Isopropyl acetate (IPA) and propyl acetate (PA) are recognized as promising biofuels suitable for applications as fuel additives and biodiesel models. The H-abstraction reactions with radicals stand out as the fundamental initiating reactions in the combustion kinetic models for IPA and PA. In the present work, the kinetic calculations of IPA and PA plus HO and OH radicals were investigated at M06-2X/cc-pVTZ//G4, M08-HX/maug-cc-pVTZ, and CCSD(T)/jul-cc-pVTZ levels. The thermodynamic calculations were obtained based on the G4 and CBS-APNO methods. Rate coefficients were calculated using both transition state theory and canonical variational transition state theory with tunneling correction at the temperature range of 250-2000 K. The total rate constants for the IPA + OH system were fitted as follows: = 0.4674 × exp(2128/) (cm mol s), and for the PA + OH system, the total rate constants were determined using the following equation: = 0.0161 × exp(2220/) (cm mol s). The rate coefficients of IPA + OH reactions determined based on the M08-HX/maug-cc-pVTZ level effectively replicate the experimental data, while H-abstraction rate coefficients of PA + OH by the CCSD(T)/jul-cc-pVTZ method accurately reproduce the experimental data. Refining the H-abstraction rate coefficients in the kinetic mechanism of PA, as proposed by Dayma et al. [Proc. Combust. Inst. 37 (2019) 429-436], has been achieved through incorporating the present calculated data, leading to the development of a revised mechanism. The validation of the updated mechanism against jet-stirred reactor data is presented, showcasing its effective performance in predicting JSR data.
乙酸异丙酯（IPA）和乙酸丙酯（PA）被认为是有前景的生物燃料，适用于作为燃料添加剂和生物柴油模型。与自由基的氢提取反应是IPA和PA燃烧动力学模型中的基本引发反应。在本工作中，在M06 - 2X/cc - pVTZ//G4、M08 - HX/maug - cc - pVTZ和CCSD(T)/jul - cc - pVTZ水平上研究了IPA和PA与HO和OH自由基的动力学计算。基于G4和CBS - APNO方法进行了热力学计算。在250 - 2000 K的温度范围内，使用过渡态理论和带有隧穿校正的正则变分过渡态理论计算速率系数。IPA + OH体系的总速率常数拟合如下： = 0.4674 × exp(2128/) (cm³ mol⁻¹ s⁻¹)，对于PA + OH体系，总速率常数由以下方程确定： = 0.0161 × exp(2220/) (cm³ mol⁻¹ s⁻¹)。基于M08 - HX/maug - cc - pVTZ水平确定的IPA + OH反应的速率系数有效地复制了实验数据，而通过CCSD(T)/jul - cc - pVTZ方法得到的PA + OH的氢提取速率系数准确地再现了实验数据。通过纳入本计算数据，对Dayma等人[《燃烧学报》37 (2019) 429 - 436]提出的PA动力学机制中的氢提取速率系数进行了改进，从而开发了一个修订机制。给出了针对喷射搅拌反应器数据对更新机制的验证，展示了其在预测喷射搅拌反应器数据方面的有效性能。
