1
|
Ahmed S, Eder SJ, Dörr N, Martini A. Tracking Thermo-Oxidation Reaction Products and Pathways of Modified Lignin Structures from Reactive Molecular Dynamics Simulations. J Phys Chem A 2024; 128:5398-5407. [PMID: 38918082 PMCID: PMC11247478 DOI: 10.1021/acs.jpca.4c00964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
Thermo-oxidation of biomass is an important process that occurs through a variety of reaction pathways depending on the chemical nature of the molecules and reaction conditions. These processes can be modeled using reactive molecular dynamics to study chemical reactions and the evolution of converted molecules over time. The advantage of this approach is that many molecules can be modeled, but it is challenging to use the large amount of data obtained from such a simulation to determine reaction products and pathways. In this study, we developed a tracking approach to identify the reaction pathways of the dominant reaction products from reactive molecular dynamics simulations. We demonstrated the approach for thermo-oxidation reactions of modified model lignin compounds. For two modified lignin structures, we tracked the evolving chemical species to find the most common reaction products. Subsequently, we monitored specific bonds to determine the individual steps in the reaction process. This combined approach of reactive molecular dynamics and tracking enabled us to identify the most likely thermo-oxidation pathways. The methodology can be used to investigate the thermo-oxidative pathways of a wider range of chemical compounds.
Collapse
Affiliation(s)
- S Ahmed
- Department of Mechanical Engineering, University of California Merced, 5200 N. Lake Road, Merced, California 95343, United States
| | - S J Eder
- AC2T research GmbH, Viktor-Kaplan-Straße 2/C, 2700 Wiener Neustadt, Austria
- Institute of Engineering Design and Product Development, TU Wien, Lehárgasse 6 - Objekt 7, 1060 Vienna, Austria
| | - N Dörr
- AC2T research GmbH, Viktor-Kaplan-Straße 2/C, 2700 Wiener Neustadt, Austria
| | - A Martini
- Department of Mechanical Engineering, University of California Merced, 5200 N. Lake Road, Merced, California 95343, United States
| |
Collapse
|
2
|
Ghavipanjeh A, Sadeghzadeh S. Simulation and experimental evaluation of laser-induced graphene on the cellulose and lignin substrates. Sci Rep 2024; 14:4475. [PMID: 38395956 PMCID: PMC10891141 DOI: 10.1038/s41598-024-54982-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 02/19/2024] [Indexed: 02/25/2024] Open
Abstract
In this article, the formation of laser-induced graphene on the two natural polymers, cellulose, and lignin, as precursors was investigated with molecular dynamics simulations and some experiments. These eco-friendly polymers provide significant industrial advantages due to their low cost, biodegradability, and recyclable aspects. It was discovered during the simulation that LIG has numerous defects and a porous structure. Carbon monoxide, H2, and water vapor are gases released by cellulose and lignin substrates. H2O and CO are released when the polymer transforms into an amorphous structure. Later on, as the amorphous structure changes into an ordered graphitic structure, H2 is released continuously. Since cellulose monomer has a higher mass proportion of oxygen (49%) than lignin monomer (29%), it emits more CO. The LIG structure contains many 5- and 7-carbon rings, which cause the structure to have bends and undulations that go out of the plane. In addition, to verify the molecular dynamics simulation results with experimental tests, we used a carbon dioxide laser to transform filter paper, as a cellulose material, and coconut shell, as a lignin material, into graphene. Surprisingly, empirical experiments confirmed the simulation results.
Collapse
Affiliation(s)
- Ali Ghavipanjeh
- School of Advanced Technologies, Iran University of Science and Technology, Tehran, Iran
| | - Sadegh Sadeghzadeh
- School of Advanced Technologies, Iran University of Science and Technology, Tehran, Iran.
| |
Collapse
|
3
|
Wang S, Wu X, Chen X. Detailed mechanism study of volatile organic compound decomposition and oxidation removal based on a ReaxFF MD method. RSC Adv 2024; 14:5863-5874. [PMID: 38362082 PMCID: PMC10865303 DOI: 10.1039/d3ra08122b] [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: 11/28/2023] [Accepted: 02/11/2024] [Indexed: 02/17/2024] Open
Abstract
Volatile organic compounds (VOCs) are typical air pollutants as well as gaseous wastes that contain energy. Utilization and disposition of VOCs is currently an important research hotspot in the field of atmospheric environment. In this paper, the thermal cracking and oxidation reaction processes of typical VOCs components were modelled and analyzed by combining molecular dynamics and detailed reaction mechanisms, focusing on the effects of temperature, oxygen and other conditions on the conversion of VOCs. The results of molecular dynamics studies show that improving temperature and reaction time benefit the decomposition of VOCs. High temperatures under an inert atmosphere can sufficiently crack the VOCs themselves, but other by-products are generated, which in turn cause secondary pollution. The activation energies derived by ReaxFF-MD calculation are 328 kJ mol-1, 147 kJ mol-1 and 121 kJ mol-1 for toluene, styrene and benzaldehyde respectively, which is consistent with experimental results. Under the oxygen atmosphere, the conversion rate of VOCs is greatly increased and the reaction temperature is significantly reduced. Meanwhile, the oxidation reaction fully converts VOCs into non-polluting products such as CO2 and H2O. Detailed kinetic studies show that initial oxidation of toluene molecules raised by hydrogen abstraction reaction is the dominant step during toluene oxidation, which significantly improved the decomposition efficiency of toluene.
Collapse
Affiliation(s)
- Shuo Wang
- Chengdu Institute of Biology, Chinese Academy of Sciences Chengdu 610041 China
| | - Xiaoqing Wu
- School of Life Science and Engineering, Southwest Jiaotong University Chengdu 610041 China
| | - Xiaozhen Chen
- Chengdu Institute of Biology, Chinese Academy of Sciences Chengdu 610041 China
| |
Collapse
|
4
|
Wannid P, Hararak B, Padee S, Klinsukhon W, Suwannamek N, Raita M, Champreda V, Prahsarn C. Fiber Melt Spinning and Thermo-Stabilization of Para-Rubber Wood Lignin: An Approach for Fully Biomass Precursor Preparation. ACS OMEGA 2023; 8:33891-33903. [PMID: 37744868 PMCID: PMC10515410 DOI: 10.1021/acsomega.3c04590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 08/21/2023] [Indexed: 09/26/2023]
Abstract
Para-rubber wood (PRW) lignin, extracted from agricultural waste, was successfully melt-spun to fibers and thermo-stabilized without employing auxiliary additives. 31P NMR analysis revealed that PRW-lignin contained mainly a syringyl unit of phenolic C5-substituted OH group, which enabled melt flow during fiber spinning, as well as a guaiacyl unit which offered the ability to cross-link during thermo-stabilization. Thermo-stabilized fibers with no fusion were achieved at 250 °C with the heating rate of 0.1 °C/min. Structural changes in the fibers during stabilization were systematically investigated using FTIR and XPS analyses. From the results, changes in the intensities of characteristic bands relating to C-H stretching, aromatic C-H stretching, and C=O stretching indicated structural changes of lignin toward aromaticity via oxidation reactions. XPS analysis of the fibers carbonized at 900, 1000, and 1200 °C revealed an increase in carbon content from 72 to 87 wt %. and a decrease in oxygen content from 28 to 13 wt %. with the increasing carbonization temperature. The weight loss of carbonized fibers was in the range of 73.6 to 88.7%. The high weight loss of fibers carbonized at 1200 °C was explained partly due to the thermal decomposition of disordered carbon. The tensile strength and modulus of carbonized fibers were 163.0 and 275.1 MPa, respectively. This study demonstrates an approach to prepare a fully biomass precursor fiber and contributes to the exploration of the potential use of lignin from biomass waste.
Collapse
Affiliation(s)
- Prapudsorn Wannid
- National
Metal and Materials Technology Center (MTEC), National Science and Technology Development Agency (NSTDA), 114 Paholyothin Road, Klong Luang, Pathum Thani 12120, Thailand
| | - Bongkot Hararak
- National
Metal and Materials Technology Center (MTEC), National Science and Technology Development Agency (NSTDA), 114 Paholyothin Road, Klong Luang, Pathum Thani 12120, Thailand
| | - Sirada Padee
- National
Metal and Materials Technology Center (MTEC), National Science and Technology Development Agency (NSTDA), 114 Paholyothin Road, Klong Luang, Pathum Thani 12120, Thailand
| | - Wattana Klinsukhon
- National
Metal and Materials Technology Center (MTEC), National Science and Technology Development Agency (NSTDA), 114 Paholyothin Road, Klong Luang, Pathum Thani 12120, Thailand
| | - Natthaphop Suwannamek
- National
Metal and Materials Technology Center (MTEC), National Science and Technology Development Agency (NSTDA), 114 Paholyothin Road, Klong Luang, Pathum Thani 12120, Thailand
| | - Marisa Raita
- National
Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency
(NSTDA), 113 Paholyothin Road, Klong Luang, Pathum Thani 12120, Thailand
| | - Verawat Champreda
- National
Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency
(NSTDA), 113 Paholyothin Road, Klong Luang, Pathum Thani 12120, Thailand
| | - Chureerat Prahsarn
- National
Metal and Materials Technology Center (MTEC), National Science and Technology Development Agency (NSTDA), 114 Paholyothin Road, Klong Luang, Pathum Thani 12120, Thailand
| |
Collapse
|
5
|
Zhang M, Zhou B, Chen Y, Gong H. Kinetic Mechanism for Simulating the Temperature and Pressure Effect on the Explosive Decomposition of Acetylene by ReaxFF Molecular Dynamics. ChemistrySelect 2023. [DOI: 10.1002/slct.202204563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Affiliation(s)
- Minhua Zhang
- Key Laboratory for Green Chemical Technology of Ministry of Education R&D Center for Petrochemical Technology Tianjin University Tianjin 300072 China
| | - Baofeng Zhou
- Key Laboratory for Green Chemical Technology of Ministry of Education R&D Center for Petrochemical Technology Tianjin University Tianjin 300072 China
| | - Yifei Chen
- Key Laboratory for Green Chemical Technology of Ministry of Education R&D Center for Petrochemical Technology Tianjin University Tianjin 300072 China
| | - Hao Gong
- Key Laboratory for Green Chemical Technology of Ministry of Education R&D Center for Petrochemical Technology Tianjin University Tianjin 300072 China
| |
Collapse
|
6
|
Dufour-Décieux V, Moakler C, Reed EJ, Cameron M. Predicting molecule size distribution in hydrocarbon pyrolysis using random graph theory. J Chem Phys 2023; 158:024101. [PMID: 36641405 DOI: 10.1063/5.0133641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Hydrocarbon pyrolysis is a complex process involving large numbers of chemical species and types of chemical reactions. Its quantitative description is important for planetary sciences, in particular, for understanding the processes occurring in the interior of icy planets, such as Uranus and Neptune, where small hydrocarbons are subjected to high temperature and pressure. We propose a computationally cheap methodology based on an originally developed ten-reaction model and the configurational model from random graph theory. This methodology generates accurate predictions for molecule size distributions for a variety of initial chemical compositions and temperatures ranging from 3200 to 5000 K. Specifically, we show that the size distribution of small molecules is particularly well predicted, and the size of the largest molecule can be accurately predicted provided that this molecule is not too large.
Collapse
Affiliation(s)
- Vincent Dufour-Décieux
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
| | - Christopher Moakler
- Department of Mathematics, University of Maryland, College Park, Maryland 20742, USA
| | - Evan J Reed
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
| | - Maria Cameron
- Department of Mathematics, University of Maryland, College Park, Maryland 20742, USA
| |
Collapse
|
7
|
Dufour-Décieux V, Ransom B, Sendek AD, Freitas R, Blanchet J, Reed EJ. Temperature Extrapolation of Molecular Dynamics Simulations of Complex Chemistry to Microsecond Timescales Using Kinetic Models: Applications to Hydrocarbon Pyrolysis. J Chem Theory Comput 2022; 18:7496-7509. [PMID: 36399110 DOI: 10.1021/acs.jctc.2c00623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We develop a method to construct temperature-dependent kinetic models of hydrocarbon pyrolysis, based on information from molecular dynamics (MD) simulations of pyrolyzing systems in the high-temperature regime. MD simulations are currently a key tool to understand the mechanism of complex chemical processes such as pyrolysis and to observe their outcomes in different conditions, but these simulations are computationally expensive and typically limited to nanoseconds of simulation time. This limitation is inconsequential at high temperatures, where equilibrium is reached quickly, but at low temperatures, the system may not equilibrate within a tractable simulation timescale. In this work, we develop a method to construct kinetic models of hydrocarbon pyrolysis using the information from the high-temperature high-reactivity regime. We then extrapolate this model to low temperatures, which enables microsecond-long simulations to be performed. We show that this approach accurately predicts the time evolution of small molecules, as well as the size and composition of long carbon chains across a wide range of temperatures and compositions. Further, we show that the range of suitable temperatures for extrapolation can easily be improved by adding more simulations to the training data. Compared to experimental results, our kinetic model leads to similar compositional trends while allowing for more detailed kinetic and mechanistic insights.
Collapse
Affiliation(s)
- Vincent Dufour-Décieux
- Department of Materials Science and Engineering, Stanford University, Stanford, California94305, United States
| | - Brandi Ransom
- Department of Materials Science and Engineering, Stanford University, Stanford, California94305, United States
| | - Austin D Sendek
- Department of Materials Science and Engineering, Stanford University, Stanford, California94305, United States.,Aionics, Inc., Palo Alto, California94301, United States
| | - Rodrigo Freitas
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Jose Blanchet
- Department of Management Science and Engineering, Stanford University, Stanford, California94305, United States
| | - Evan J Reed
- Department of Materials Science and Engineering, Stanford University, Stanford, California94305, United States
| |
Collapse
|
8
|
Molecular dynamics and steady-state process simulation coupled research on CCLG system design for cleaner production of EG. J Taiwan Inst Chem Eng 2022. [DOI: 10.1016/j.jtice.2022.104597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
9
|
A Review on the Effect of the Mechanism of Organic Polymers on Pellet Properties for Iron Ore Beneficiation. Polymers (Basel) 2022; 14:polym14224874. [PMID: 36433001 PMCID: PMC9698213 DOI: 10.3390/polym14224874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/01/2022] [Accepted: 11/08/2022] [Indexed: 11/15/2022] Open
Abstract
Iron ore pellets not only have excellent metallurgical and mechanical properties but are also essential raw materials for improving iron and steel smelting in the context of the increasing global depletion of high-grade iron ore resources. Organic polymers, as important additive components for the production of high-quality pellets, have a significant impact on the formation as well as the properties of pellets. In this review, the mechanisms of organic polymers on the pelletizing properties, bursting temperature, and pellet strength at low and high temperatures, as well as the existing measures and mechanisms to improve the high-temperature strength of the organic binder pellets are systematically summarized. Compared with traditional bentonite additives, the organic polymers greatly improve the pelletizing rate and pellet strength at low temperatures, and significantly reduces metallurgical pollution. However, organic binders often lead to a decrease in pellet bursting temperature and pellet strength at high temperatures, which can be significantly improved by compounding with a small amount of low-cost inorganic minerals, such as bentonite, boron-containing compounds, sodium salts, and copper slag. At the same time, some industrial solid wastes can be rationally used to reduce the cost of pellet binders.
Collapse
|
10
|
Liu Z, Ku X, Jin H. Pyrolysis Mechanism of Wheat Straw Based on ReaxFF Molecular Dynamics Simulations. ACS OMEGA 2022; 7:21075-21085. [PMID: 35755388 PMCID: PMC9218979 DOI: 10.1021/acsomega.2c01899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Biomass has played an increasingly important role in the consumption of energy worldwide because of its renewability and carbon-neutral property. In this work, the pyrolysis mechanism of wheat straw is explored using reactive force field molecular dynamics simulations. A large-scale wheat straw model composed of cellulose, hemicellulose, and lignin is built. After model validation, the temporal evolutions of the main pyrolysis products under different temperatures are analyzed. As the temperature rises, the gas production increases and the tar yield can decrease after peaking. Relatively high temperatures accelerate the generation rates of the main gas and tar species. CO and CO2 molecules mainly come from the cleavage of CHO2 radicals, and numerous H2O molecules are generated on account of dehydration. Moreover, the evolution of six functional groups and pyran and phenyl rings as well as three types of bonds is also presented. It is observed that the phenyl rings reflect improved thermostability. Finally, the pyrolytic kinetics analysis is conducted, and the estimated activation energy of wheat straw pyrolysis is found to be 56.19 kJ/mol. All these observations can help deeply understand the pyrolytic mechanism of wheat straw biomass.
Collapse
Affiliation(s)
- Zhiwei Liu
- Department
of Engineering Mechanics, Zhejiang University, 310027 Hangzhou, China
| | - Xiaoke Ku
- Department
of Engineering Mechanics, Zhejiang University, 310027 Hangzhou, China
- State
Key Laboratory of Clean Energy Utilization, Zhejiang University, 310027 Hangzhou, China
| | - Hanhui Jin
- Department
of Engineering Mechanics, Zhejiang University, 310027 Hangzhou, China
| |
Collapse
|
11
|
Jana A, Zhu T, Wang Y, Adams JJ, Kearney LT, Naskar AK, Grossman JC, Ferralis N. Atoms to fibers: Identifying novel processing methods in the synthesis of pitch-based carbon fibers. SCIENCE ADVANCES 2022; 8:eabn1905. [PMID: 35302858 PMCID: PMC8932655 DOI: 10.1126/sciadv.abn1905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Understanding and optimizing the key mechanisms used in the synthesis of pitch-based carbon fibers (CFs) are challenging, because unlike polyacrylonitrile-based CFs, the feedstock for pitch-based CFs is chemically heterogeneous, resulting in complex fabrication leading to inconsistency in the final properties. In this work, we use molecular dynamics simulations to explore the processing and chemical phase space through a framework of CF models to identify their effects on elastic performance. The results are in excellent agreement with experiments. We find that density, followed by alignment, and functionality of the molecular constituents dictate the CF mechanical properties more strongly than their size and shape. Last, we propose a previously unexplored fabrication route for high-modulus CFs. Unlike graphitization, this results in increased sp3 fraction, achieved via generating high-density CFs. In addition, the high sp3 fraction leads to the fabrication of CFs with isometric compressive and tensile moduli, enabling their potential applications for compressive loading.
Collapse
Affiliation(s)
- Asmita Jana
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Taishan Zhu
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yanming Wang
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - Logan T. Kearney
- Carbon and Composites Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Amit K. Naskar
- Carbon and Composites Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Jeffrey C. Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Nicola Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| |
Collapse
|
12
|
De Santi A, Monti S, Barcaro G, Zhang Z, Barta K, Deuss PJ. New Mechanistic Insights into the Lignin β-O-4 Linkage Acidolysis with Ethylene Glycol Stabilization Aided by Multilevel Computational Chemistry. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2021; 9:2388-2399. [PMID: 33585085 PMCID: PMC7874265 DOI: 10.1021/acssuschemeng.0c08901] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/08/2021] [Indexed: 06/01/2023]
Abstract
Acidolysis in conjunction with stabilization of reactive intermediates has emerged as one of the most powerful methods of lignin depolymerization that leads to high aromatic monomer yields. In particular, stabilization of reactive aldehydes using ethylene glycol results in the selective formation of the corresponding cyclic acetals (1,3-dioxolane derivatives) from model compounds, lignin, and even from softwood lignocellulose. Given the high practical utility of this method for future biorefineries, a deeper understanding of the method is desired. Here, we aim to elucidate key mechanistic questions utilizing a combination of experimental and multilevel computational approaches. The multiscale computational protocol used, based on ReaxFF molecular dynamics, represents a realistic scenario, where a typical experimental setup can be reproduced confidently given the explicit molecules of the solute, catalyst, and reagent. The nudged elastic band (NEB) approach allowed us to characterize the key intermolecular interactions involved in the reaction paths leading to crucial intermediates and products. The high level of detail obtained clearly revealed for the first time the unique role of sulfuric acid as a proton donor and acceptor in lignin β-O-4 acidolysis as well as the reaction pathways for ethylene glycol stabilization, and the difference in reactivity between compounds with different methoxy substituents.
Collapse
Affiliation(s)
- Alessandra De Santi
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
- Department
of Chemical Engineering (ENTEG), University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Susanna Monti
- CNR-ICCOM−
Institute of Chemistry of Organometallic Compounds, via Moruzzi 1, 56124 Pisa, Italy
| | - Giovanni Barcaro
- CNR-IPCF−Institute
for Chemical and Physical Processes, via Moruzzi 1, 56124 Pisa, Italy
| | - Zhenlei Zhang
- Department
of Chemical Engineering (ENTEG), University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Katalin Barta
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
- Department
of Chemistry, Organic and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28/II, 8010 Graz, Austria
| | - Peter J. Deuss
- Department
of Chemical Engineering (ENTEG), University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| |
Collapse
|
13
|
Bertels LW, Newcomb LB, Alaghemandi M, Green JR, Head-Gordon M. Benchmarking the Performance of the ReaxFF Reactive Force Field on Hydrogen Combustion Systems. J Phys Chem A 2020; 124:5631-5645. [DOI: 10.1021/acs.jpca.0c02734] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Luke W. Bertels
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Lucas B. Newcomb
- Department of Chemistry, University of Massachusetts Boston, Boston, Massachusetts 02125, United States
| | - Mohammad Alaghemandi
- Department of Chemistry, University of Massachusetts Boston, Boston, Massachusetts 02125, United States
| | - Jason R. Green
- Department of Chemistry, University of Massachusetts Boston, Boston, Massachusetts 02125, United States
- Department of Physics, University of Massachusetts Boston, Boston, Massachusetts 02125, United States
| | - Martin Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| |
Collapse
|
14
|
Zhang C, Shomali A, Guyer R, Keten S, Coasne B, Derome D, Carmeliet J. Disentangling Heat and Moisture Effects on Biopolymer Mechanics. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b01988] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chi Zhang
- Chair of Building Physics, Department of Mechanical and Process Engineering, ETH Zurich, 8093 Zurich, Switzerland
- Laboratory for Multiscale Studies in Building Physics, Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland
| | - Ali Shomali
- Chair of Building Physics, Department of Mechanical and Process Engineering, ETH Zurich, 8093 Zurich, Switzerland
| | - Robert Guyer
- Department of Physics, University of Nevada, Reno, 1664 N. Virginia Street, Reno, Nevada 89557, United States
| | - Sinan Keten
- Department of Civil and Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3109, United States
| | - Benoit Coasne
- CNRS, LIPhy, Université Grenoble Alpes, 38000 Grenoble, France
| | - Dominique Derome
- Laboratory for Multiscale Studies in Building Physics, Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland
| | - Jan Carmeliet
- Chair of Building Physics, Department of Mechanical and Process Engineering, ETH Zurich, 8093 Zurich, Switzerland
| |
Collapse
|
15
|
Wang F, Yu YZ, Chen Y, Yang CY, Yang YY. One-step alcoholysis of lignin into small-molecular aromatics: Influence of temperature, solvent, and catalyst. ACTA ACUST UNITED AC 2019; 24:e00363. [PMID: 31440458 PMCID: PMC6698935 DOI: 10.1016/j.btre.2019.e00363] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 07/04/2019] [Accepted: 07/26/2019] [Indexed: 12/30/2022]
Abstract
The reactant suspension mode is an effective strategy to deoxy-liquefaction of lignin. The catalyst Cu-C has the optimal catalytic activity and selectivity in methanol. The catalyst Fe-SiC possesses the optimal catalytic deoxygenation in ethanol. The cleavages of C—O ether bonds and C—C bonds directly promote the formation of small-molecular aromatics.
Lignin valorization is a challenge because of its complex structure and high thermal stability. Supercritical alcoholysis of lignin without external hydrogen in a self-made high-pressure reactor is investigated under different temperatures (450–500 °C) and solvents as well as catalysts by using a reactant suspension mode. Small-molecular arenes and mono-phenols (C7-C12) are generated under short residence time of 30 min. High temperature (500 °C) favors efficient deoxy-liquefaction of lignin (70%) and formation of small-molecular arenes (C6-C9). Solvents methanol and ethanol demonstrate much more synergistic effect on efficient deoxy-liquefaction of lignin than propanol. The catalyst Cu-C has the optimal activity and selectivity in methanol (70% of conversion, 83.93% of arenes), whereas Fe-SiC possesses the optimal catalytic deoxygenation in ethanol, resulting in the formation of arenes other than phenols. Further analysis indicates that lignin is converted into arenes by efficient cleavages of C—O ether bonds and C—C bonds under high temperature and pressure.
Collapse
Affiliation(s)
- Fang Wang
- Department of Chemical and Environmental Engineering, Anyang Institute of Technology, Anyang 455000, China
| | - You-Zhu Yu
- Key Laboratory of Magnetic Molecules and Magnetic Information Material of Ministry of Education, School of Chemistry and Material Science, Shanxi Normal University, Linfen 041004, China
| | - Yigang Chen
- Key Laboratory of Magnetic Molecules and Magnetic Information Material of Ministry of Education, School of Chemistry and Material Science, Shanxi Normal University, Linfen 041004, China
| | - Chun-Yu Yang
- Key Laboratory of Magnetic Molecules and Magnetic Information Material of Ministry of Education, School of Chemistry and Material Science, Shanxi Normal University, Linfen 041004, China
| | - Yuan-Yu Yang
- Key Laboratory of Magnetic Molecules and Magnetic Information Material of Ministry of Education, School of Chemistry and Material Science, Shanxi Normal University, Linfen 041004, China
| |
Collapse
|
16
|
Kulik HJ. MODELING MECHANOCHEMISTRY FROM FIRST PRINCIPLES. REVIEWS IN COMPUTATIONAL CHEMISTRY 2018. [DOI: 10.1002/9781119518068.ch6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
17
|
Monti S, Srifa P, Kumaniaev I, Samec JSM. ReaxFF Simulations of Lignin Fragmentation on a Palladium-Based Heterogeneous Catalyst in Methanol-Water Solution. J Phys Chem Lett 2018; 9:5233-5239. [PMID: 30130109 DOI: 10.1021/acs.jpclett.8b02275] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The interaction of fragments derived from lignin depolymerization with a heterogeneous palladium catalyst in methanol-water solution is studied by means of experimental and theoretical methodologies. Quantum chemistry calculations and molecular dynamics simulations based on the ReaxFF approach are combined effectively to obtain an atomic level characterization of the crucial steps of the adsorption of the molecules on the catalyst, their fragmentation, reactions, and desorption. The main products are identified, and the most important routes to obtain them are explained through extensive computational procedures. The simulation results are in excellent agreement with the experiments and suggest that the mechanisms comprise a fast chemisorption of identified fragments from lignin on the metal interface accompanied by bond breaking, release of some of their hydrogens and oxygens to the support, and eventual desorption depending on the local environment. The strongest connections are those involving the aromatic rings, as confirmed by the binding energies of selected representative structures, estimated at the quantum chemistry level. The satisfactory agreement with the literature, quantum chemistry data, and experiments confirms the reliability of the multilevel computational procedure to study complex reaction mixtures and its potential application in the design of high-performance catalytic devices.
Collapse
Affiliation(s)
- Susanna Monti
- CNR-ICCOM , Institute of Chemistry of Organometallic Compounds , via G. Moruzzi 1 , I-56124 Pisa , Italy
| | - Pemikar Srifa
- Department of Organic Chemistry, Arrhenius Laboratory , Stockholm University , S-106 91 Stockholm , Sweden
| | - Ivan Kumaniaev
- Department of Organic Chemistry, Arrhenius Laboratory , Stockholm University , S-106 91 Stockholm , Sweden
| | - Joseph S M Samec
- Department of Organic Chemistry, Arrhenius Laboratory , Stockholm University , S-106 91 Stockholm , Sweden
| |
Collapse
|
18
|
Martin-Martinez FJ, Jin K, López Barreiro D, Buehler MJ. The Rise of Hierarchical Nanostructured Materials from Renewable Sources: Learning from Nature. ACS NANO 2018; 12:7425-7433. [PMID: 30102024 PMCID: PMC6467252 DOI: 10.1021/acsnano.8b04379] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Mimicking Nature implies the use of bio-inspired hierarchical designs to manufacture nanostructured materials. Such materials should be produced from sustainable sources ( e.g., biomass) and through simple processes that use mild conditions, enabling sustainable solutions. The combination of different types of nanomaterials and the implementation of different features at different length scales can provide synthetic hierarchical nanostructures that mimic natural materials, outperforming the properties of their constitutive building blocks. Taking recent developments in flow-assisted assembly of nanocellulose crystals as a starting point, we review the state of the art and provide future perspectives on the manufacture of hierarchical nanostructured materials from sustainable sources, assembly techniques, and potential applications.
Collapse
Affiliation(s)
- Francisco J Martin-Martinez
- Department of Civil and Environmental Engineering , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , Massachusetts 02139 , United States
| | - Kai Jin
- Department of Civil and Environmental Engineering , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , Massachusetts 02139 , United States
| | - Diego López Barreiro
- Department of Civil and Environmental Engineering , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , Massachusetts 02139 , United States
| | - Markus J Buehler
- Department of Civil and Environmental Engineering , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , Massachusetts 02139 , United States
| |
Collapse
|
19
|
Yin F, Tang C, Wang Q, Liu X, Tang Y. Molecular Dynamics Simulations on the Thermal Decomposition of Meta-Aramid Fibers. Polymers (Basel) 2018; 10:E691. [PMID: 30960616 PMCID: PMC6403965 DOI: 10.3390/polym10070691] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 06/17/2018] [Accepted: 06/19/2018] [Indexed: 11/17/2022] Open
Abstract
The thermal decomposition mechanism of a meta-aramid fiber was simulated at the atomic level using the ReaxFF reactive force field. The simulation results indicated that the main initial decomposition positions of the meta-aramid fiber elements were Caromatic ring⁻N and C=O, which could be used as targets for the modification of meta-aramid fibers. The meta-aramid fiber elements first decomposed into C6⁻C13 and then into smaller segments and micromolecular gases. The temperature was shown to be the key factor affecting the thermal decomposition of the meta-aramid fibers. More complex compositions and stable gases were produced at high temperatures than at lower temperatures. HCN was a decomposition product at high temperature, suggesting that its presence could be used for detecting thermal faults in meta-aramid fibers. Generation path tracing of the thermal decomposition products NH₃ and H₂O was also performed. NH₃ was produced when the NH₂ group captured an H atom adjacent to the system. H₂O was formed after a carbonyl group captured an H atom, became a hydroxyl group, with subsequent intramolecular dehydration or intermolecular hydrogen abstraction.
Collapse
Affiliation(s)
- Fei Yin
- College of Engineering and Technology, Southwest University, Chongqing 400715, China.
| | - Chao Tang
- College of Engineering and Technology, Southwest University, Chongqing 400715, China.
| | - Qian Wang
- Electric Power Research Institute of State Grid Chongqing Electric Power Company, Chongqing 401123, China.
| | - Xiong Liu
- Electric Power Research Institute of State Grid Chongqing Electric Power Company, Chongqing 401123, China.
| | - Yujing Tang
- College of Engineering and Technology, Southwest University, Chongqing 400715, China.
| |
Collapse
|
20
|
Qin Y, Li G, Gao Y, Zhang L, Ok YS, An T. Persistent free radicals in carbon-based materials on transformation of refractory organic contaminants (ROCs) in water: A critical review. WATER RESEARCH 2018; 137:130-143. [PMID: 29547776 DOI: 10.1016/j.watres.2018.03.012] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 03/02/2018] [Accepted: 03/05/2018] [Indexed: 06/08/2023]
Abstract
With the increased concentrations and kinds of refractory organic contaminants (ROCs) in aquatic environments, many previous reviews systematically summarized the applications of carbon-based materials in the adsorption and catalytic degradation of ROCs for their economically viable and environmentally friendly behavior. Interestingly, recent studies indicated that carbon-based materials in natural environment can also mediate the transformation of ROCs directly or indirectly due to their abundant persistent free radicals (PFRs). Understanding the formation mechanisms of PFRs in carbo-based materials and their interactions with ROCs is essential to develop their further applications in environment remediation. However, there is no comprehensive review so far about the direct and indirect removal of ROCs mediated by PFRs in amorphous, porous and crystalline carbon-based materials. The review aims to evaluate the formation mechanisms of PFRs in carbon-based materials synthesized through pyrolysis and hydrothermal carbonization processes. The influence of synthesis conditions (temperature and time) and carbon sources on the types as well as the concentrations of PFRs in carbon-based materials are also discussed. In particular, the effects of metals on the concentrations and types of PFRs in carbon-based materials are highlighted because they are considered as the catalysts for the formation of PFRs. The formation mechanisms of reactive species and the further transformation mechanisms of ROCs are briefly summarized, and the surface properties of carbon-based materials including surface area, types and number of functional groups, etc. are found to be the key parameters controlling their activities. However, due to diversity and complexity of carbon-based materials, the exact relationships between the activities of carbon-based materials and PFRs are still uncertain. Finally, the existing problems and current challenges for the ROCs transformation with carbon-based materials are also pointed out.
Collapse
Affiliation(s)
- Yaxin Qin
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Guiying Li
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Yanpeng Gao
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Lizhi Zhang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, China
| | - Yong Sik Ok
- Korea Biochar Research Center, O-Jeong Eco-Resilience Institute & Division of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Taicheng An
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
| |
Collapse
|
21
|
Chen C, Zhao L, Wang J, Lin S. Reactive Molecular Dynamics Simulations of Biomass Pyrolysis and Combustion under Various Oxidative and Humidity Environments. Ind Eng Chem Res 2017. [DOI: 10.1021/acs.iecr.7b01714] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chao Chen
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy & Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Lingling Zhao
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy & Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Jingfan Wang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy & Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Shangchao Lin
- Department of Mechanical Engineering, Materials Science & Engineering Program, FAMU-FSU College of Engineering, Florida State University, Tallahassee, Florida 32310, United States
| |
Collapse
|
22
|
Zheng M, Li X, Nie F, Guo L. Investigation of model scale effects on coal pyrolysis using ReaxFF MD simulation. MOLECULAR SIMULATION 2017. [DOI: 10.1080/08927022.2017.1356456] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Mo Zheng
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, P. R. China
| | - Xiaoxia Li
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, P. R. China
- School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, P. R. China
| | - Fengguang Nie
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, P. R. China
| | - Li Guo
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, P. R. China
- School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, P. R. China
| |
Collapse
|
23
|
Sánchez-González Á, Martín-Martínez FJ, Dobado JA. The role of weak interactions in lignin polymerization. J Mol Model 2017; 23:80. [DOI: 10.1007/s00894-017-3257-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 01/23/2017] [Indexed: 10/20/2022]
|
24
|
Ashraf C, van Duin AC. Extension of the ReaxFF Combustion Force Field toward Syngas Combustion and Initial Oxidation Kinetics. J Phys Chem A 2017; 121:1051-1068. [DOI: 10.1021/acs.jpca.6b12429] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Chowdhury Ashraf
- Department of Mechanical
and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Adri C.T. van Duin
- Department of Mechanical
and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| |
Collapse
|
25
|
Mar BD, Kulik HJ. Depolymerization Pathways for Branching Lignin Spirodienone Units Revealed with ab Initio Steered Molecular Dynamics. J Phys Chem A 2017; 121:532-543. [PMID: 28005362 DOI: 10.1021/acs.jpca.6b11414] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lignocellulosic biomass is an abundant, rich source of aromatic compounds, but direct utilization of raw lignin has been hampered by both the high heterogeneity and variability of linking bonds in this biopolymer. Ab initio steered molecular dynamics (AISMD) has emerged both as a fruitful direct computational screening approach to identify products that occur through mechanical depolymerization (i.e., in sonication or ball-milling) and as a sampling approach. By varying the direction of force and sampling over 750 AISMD trajectories, we identify numerous possible pathways through which lignin depolymerization may occur in pyrolysis or through catalytic depolymerization as well. Here, we present eight unique major depolymerization pathways discovered via AISMD for the recently characterized spirodienone lignin branching linkage that may comprise around 10% weight of all lignin in some softwoods. We extract representative trajectories from AISMD and carry out reaction pathway analysis to identify energetically favorable pathways for lignin depolymerization. Importantly, we identify dynamical effects that could not be observed through more traditional calculations of bond dissociation energies. Such effects include thermodynamically favorable recovery of aromaticity in the dienone ring that leads to near-barrierless subsequent ether cleavage and hydrogen-bonding effects that stabilize newly formed radicals. Some of the most stable spirodienone fragments that reside at most 1 eV above the reactant structure are formed with only 2 eV barriers for C-C bond cleavage, suggesting key targets for catalyst design to drive targeted depolymerization of lignin.
Collapse
Affiliation(s)
- Brendan D Mar
- Department of Chemical Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Heather J Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| |
Collapse
|
26
|
Petridis L, Smith JC. Conformations of Low-Molecular-Weight Lignin Polymers in Water. CHEMSUSCHEM 2016; 9:289-295. [PMID: 26763657 DOI: 10.1002/cssc.201501350] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 12/04/2015] [Indexed: 06/05/2023]
Abstract
Low-molecular-weight lignin binds to cellulose during the thermochemical pretreatment of biomass for biofuel production, which prevents the efficient hydrolysis of the cellulose to sugars. The binding properties of lignin are influenced strongly by the conformations it adopts. Here, we use molecular dynamics simulations in aqueous solution to investigate the dependence of the shape of lignin polymers on chain length and temperature. Lignin is found to adopt collapsed conformations in water at 300 and 500 K. However, at 300 K, a discontinuous transition is found in the shape of the polymer as a function of the chain length. Below a critical degree of polymerization, Nc =15, the polymer adopts less spherical conformations than above Nc. The transition disappears at high temperatures (500 K) at which only spherical shapes are adopted. An implication relevant to cellulosic biofuel production is that lignin will self-aggregate even at high pretreatment temperatures.
Collapse
Affiliation(s)
- Loukas Petridis
- Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
| | - Jeremy C Smith
- Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| |
Collapse
|
27
|
Han Y, Jiang D, Zhang J, Li W, Gan Z, Gu J. Development, applications and challenges of ReaxFF reactive force field in molecular simulations. Front Chem Sci Eng 2015. [DOI: 10.1007/s11705-015-1545-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
28
|
Mar BD, Qi HW, Liu F, Kulik HJ. Ab Initio Screening Approach for the Discovery of Lignin Polymer Breaking Pathways. J Phys Chem A 2015; 119:6551-62. [PMID: 26001164 DOI: 10.1021/acs.jpca.5b03503] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The directed depolymerization of lignin biopolymers is of utmost relevance for the valorization or commercialization of biomass fuels. We present a computational and theoretical screening approach to identify potential cleavage pathways and resulting fragments that are formed during depolymerization of lignin oligomers containing two to six monomers. We have developed a chemical discovery technique to identify the chemically relevant putative fragments in eight known polymeric linkage types of lignin. Obtaining these structures is a crucial precursor to the development of any further kinetic modeling. We have developed this approach by adapting steered molecular dynamics calculations under constant force and varying the points of applied force in the molecule to diversify the screening approach. Key observations include relationships between abundance and breaking frequency, the relative diversity of potential pathways for a given linkage, and the observation that readily cleaved bonds can destabilize adjacent bonds, causing subsequent automatic cleavage.
Collapse
Affiliation(s)
| | | | - Fang Liu
- §Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | | |
Collapse
|
29
|
Carmona C, Langan P, Smith JC, Petridis L. Why genetic modification of lignin leads to low-recalcitrance biomass. Phys Chem Chem Phys 2015; 17:358-64. [DOI: 10.1039/c4cp05004e] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Molecular dynamics simulations show genetically modified lignin to associate less with hemicellulose than does wild type.
Collapse
Affiliation(s)
- Christopher Carmona
- University of California
- Los Angeles
- Los Angeles
- USA
- Center for Molecular Biophysics
| | - Paul Langan
- Biology and Soft Matter Division
- Oak Ridge
- USA
| | - Jeremy C. Smith
- Center for Molecular Biophysics
- Oak Ridge National Laboratory
- Oak Ridge
- USA
- Department of Biochemistry and Cellular and Molecular Biology
| | - Loukas Petridis
- Center for Molecular Biophysics
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| |
Collapse
|
30
|
Lignin hydrolysis and phosphorylation mechanism during phosphoric acid-acetone pretreatment: a DFT study. Molecules 2014; 19:21335-49. [PMID: 25529020 PMCID: PMC6271813 DOI: 10.3390/molecules191221335] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 12/07/2014] [Accepted: 12/08/2014] [Indexed: 11/16/2022] Open
Abstract
The study focused on the structural sensitivity of lignin during the phosphoric acid–acetone pretreatment process and the resulting hydrolysis and phosphorylation reaction mechanisms using density functional theory calculations. The chemical stabilities of the seven most common linkages (β-O-4, β-β, 4-O-5, β-1, 5-5, α-O-4, and β-5) of lignin in H3PO4, CH3COCH3, and H2O solutions were detected, which shows that α-O-4 linkage and β-O-4 linkage tend to break during the phosphoric acid–acetone pretreatment process. Then α-O-4 phosphorylation and β-O-4 phosphorylation follow a two-step reaction mechanism in the acid treatment step, respectively. However, since phosphorylation of α-O-4 is more energetically accessible than phosphorylation of β-O-4 in phosphoric acid, the phosphorylation of α-O-4 could be controllably realized under certain operational conditions, which could tune the electron and hole transfer on the right side of β-O-4 in the H2PO4− functionalized lignin. The results provide a fundamental understanding for process-controlled modification of lignin and the potential novel applications in lignin-based imprinted polymers, sensors, and molecular devices.
Collapse
|