1
|
Taguchi K, Gilbert A, Sherwood Lollar B, Giunta T, Boreham CJ, Liu Q, Horita J, Ueno Y. Low 13C- 13C abundances in abiotic ethane. Nat Commun 2022; 13:5790. [PMID: 36184637 PMCID: PMC9527245 DOI: 10.1038/s41467-022-33538-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 09/22/2022] [Indexed: 11/09/2022] Open
Abstract
Distinguishing biotic compounds from abiotic ones is important in resource geology, biogeochemistry, and the search for life in the universe. Stable isotopes have traditionally been used to discriminate the origins of organic materials, with particular focus on hydrocarbons. However, despite extensive efforts, unequivocal distinction of abiotic hydrocarbons remains challenging. Recent development of clumped-isotope analysis provides more robust information because it is independent of the stable isotopic composition of the starting material. Here, we report data from a 13C-13C clumped-isotope analysis of ethane and demonstrate that the abiotically-synthesized ethane shows distinctively low 13C-13C abundances compared to thermogenic ethane. A collision frequency model predicts the observed low 13C-13C abundances (anti-clumping) in ethane produced from methyl radical recombination. In contrast, thermogenic ethane presumably exhibits near stochastic 13C-13C distribution inherited from the biological precursor, which undergoes C-C bond cleavage/recombination during metabolism. Further, we find an exceptionally high 13C-13C signature in ethane remaining after microbial oxidation. In summary, the approach distinguishes between thermogenic, microbially altered, and abiotic hydrocarbons. The 13C-13C signature can provide an important step forward for discrimination of the origin of organic molecules on Earth and in extra-terrestrial environments.
Collapse
Affiliation(s)
- Koudai Taguchi
- Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro, Tokyo, 152-8551, Japan.
| | - Alexis Gilbert
- Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro, Tokyo, 152-8551, Japan. .,Earth-Life Science Institute (WPI-ELSI), Tokyo Institute of Technology, Meguro, Tokyo, 152-8550, Japan.
| | - Barbara Sherwood Lollar
- Department of Earth Sciences, University of Toronto, Toronto, ON, M5S 3B1, Canada.,Institut de physique du globe de Paris (IPGP), Université Paris Cité, Paris, France
| | - Thomas Giunta
- Department of Earth Sciences, University of Toronto, Toronto, ON, M5S 3B1, Canada.,Univ Brest, CNRS, Ifremer, Geo-Ocean, F-29280, Plouzané, France
| | | | - Qi Liu
- State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
| | - Juske Horita
- Department of Geosciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Yuichiro Ueno
- Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro, Tokyo, 152-8551, Japan. .,Earth-Life Science Institute (WPI-ELSI), Tokyo Institute of Technology, Meguro, Tokyo, 152-8550, Japan. .,Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Natsushima-cho, Yokosuka, 237-0061, Japan.
| |
Collapse
|
2
|
Wang CH, Panteleev SV, Masunov AE, Allison TC, Chang S, Lim C, Jin Y, Vasu SS. Molecular Dynamics of Combustion Reactions in Supercritical Carbon Dioxide. Part 5: Computational Study of Ethane Dissociation and Recombination Reactions C 2H 6 ⇌ CH 3 + CH 3. J Phys Chem A 2019; 123:4776-4784. [PMID: 31034229 DOI: 10.1021/acs.jpca.9b02302] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Fossil fuel oxy-combustion is an emerging technology where the habitual nitrogen diluent is replaced by high-pressure supercritical CO2 (sCO2), which increases the efficiency of energy conversion. In this study, the chemical kinetics of the combustion reaction C2H6 ⇌ CH3 + CH3 in the sCO2 environment is predicted at 30-1000 atm and 1000-2000 K. We adopt a multiscale approach, where the reactive complex is treated quantum mechanically in rigid rotor/harmonic oscillator approximation, while environment effects at different densities are taken into account by the potential of mean force, produced with classical molecular dynamics (MD). Here, we used boxed MD, where enhanced sampling of infrequent events of barrier crossing is accomplished without application of the bias potential. The multistate empirical valence bond model is applied to describe free radical formation accurately at the cost of the classical force field. Predicted rates at low densities agree well with the literature data. Rate constants at 300 atm are 2.41 × 1014 T-0.20 exp(-77.03 kcal/mol/ RT) 1/s for ethane dissociation and 8.44 × 10-19 T1.42 exp(19.89 kcal/mol/ RT) cm3/molecule/s for methyl-methyl recombination.
Collapse
Affiliation(s)
- Chun-Hung Wang
- NanoScienece Technology Center , University of Central Florida , 12424 Research Parkway , Orlando , Florida 32826 , United States
| | - Sergey V Panteleev
- N. I. Lobachevsky State University of Nizhny Novgorod , Gagarin Av. 23 , Nizhny Novgorod 603950 , Russia
| | - Artëm E Masunov
- NanoScienece Technology Center , University of Central Florida , 12424 Research Parkway , Orlando , Florida 32826 , United States.,Department of Chemistry , University of Central Florida , 4111 Libra Dr. , Orlando , Florida 32816 , United States.,South Ural State University , Lenin pr. 76 , Chelyabinsk 454080 , Russia.,National Research Nuclear University MEPhI , Kashirskoye shosse 31 , Moscow 115409 , Russia
| | - Timothy C Allison
- Southwest Research Institute , San Antonio , Texas 78238 , United States
| | - Sungho Chang
- KEPCO Research Institute , Daejeon 34050 , Korea
| | - Chansun Lim
- Hanwha Power Systems , Seongnam , Gyeonggi 13488 , Korea
| | - Yuin Jin
- Hanwha Power Systems , Seongnam , Gyeonggi 13488 , Korea
| | - Subith S Vasu
- Center for Advanced Turbomachinery and Energy Research (CATER), Mechanical and Aerospace Engineering , University of Central Florida , Orlando , Florida 32816 , United States
| |
Collapse
|
3
|
Baradyn M, Ratkiewicz A. Kinetics of the Hydrogen Abstraction PAH + •OH → PAH Radical + H 2O Reaction Class: An Application of the Reaction Class Transition State Theory (RC-TST) and Structure-Activity Relationship (SAR). J Phys Chem A 2019; 123:750-763. [PMID: 30596495 DOI: 10.1021/acs.jpca.8b10988] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A reaction class transition state theory (RC-TST) augmented with structure-activity relationship (SAR) methodology is applied to predict high-pressure limit thermal rate constants for hydrogen abstraction by •OH radical from polycyclic aromatic hydrocarbons (PAHs) reaction class in the temperature range of 300-3000 K. The rate constants for the reference reaction of C6H6 + •OH → C6H5 + H2O is calculated by the canonical variational transition state theory (CVT) with small curvature tunneling (SCT). Only the reaction energy is needed to predict RC-TST rates for other processes within the family, the parameters needed were obtained from M06-2X/cc-pVTZ data for a training set of 34 reactions. The systematic error of the resulting RC-TST rates is smaller than 50% in comparison with explicit rate calculations, which facilitates application of the proposed methodology to the automated reaction mechanism generators (ARMGs) schemes.
Collapse
Affiliation(s)
- Maciej Baradyn
- Institute of Chemistry , University of Bialystok , ul. Ciolkowskiego 1K 15-245 Bialystok , Poland
| | - Artur Ratkiewicz
- Institute of Chemistry , University of Bialystok , ul. Ciolkowskiego 1K 15-245 Bialystok , Poland
| |
Collapse
|
4
|
Mai TVT, Ratkiewicz A, Le A, Duong MV, Truong TN, Huynh LK. On-the-fly kinetics of hydrogen abstraction from polycyclic aromatic hydrocarbons by methyl/ethyl radicals. Phys Chem Chem Phys 2018; 20:23578-23592. [PMID: 30188552 DOI: 10.1039/c8cp03718c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
This work provides a rigorous procedure, within the framework of the Reaction Class Transition State Theory (RC-TST) and the Structure-Activity Relationship (SAR), for predicting reliable thermal rate constants on-the-fly for hydrogen abstraction reactions by methyl/ethyl radicals from Polycyclic Aromatic Hydrocarbons (PAHs) in a temperature range of 300-3000 K. All necessary RC-TST parameters were derived from ab initio calculations for a representative set of 36 reactions on which different error analyses and comparisons with available literature data were carried out. In addition to the good agreement between the RC-TST rate constants and the literature data, the detailed error analyses show that RC-TST/SAR, utilizing either the Linear Energy Relationship (LER) where only the reaction energy is needed or Barrier Height Grouping (BHG) where no additional data is needed, can predict the thermal rate constants for any reaction in the title reaction class with an average systematic error of less than 50% when compared to the explicit rate calculations. Therefore, the constructed RC-TST procedure can be confidently used to obtain reliable rate constants on the fly in an attempt to effectively construct detailed kinetic mechanisms for PAH-related fuels.
Collapse
Affiliation(s)
- Tam V-T Mai
- Institute for Computational Science and Technology, Ho-Chi-Minh City, Vietnam
| | | | | | | | | | | |
Collapse
|