Theoretical Study on the Mechanism of Hydrogen Donation and Transfer for Hydrogen-Donor Solvents during Direct Coal Liquefaction

As a country that is poor in petroleum yet rich in coal, it is significant for China to develop direct coal liquefaction (DCL) technology to relieve the pressure from petroleum shortages to guarantee national energy security. To improve the efficiency of the direct coal liquefaction process, scienti...

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Main Authors: Haigang Hao, Tong Chang, Linxia Cui, Ruiqing Sun, Rui Gao
Format: Article
Language:English
Published: MDPI AG 2018-12-01
Series:Catalysts
Subjects:
Online Access:https://www.mdpi.com/2073-4344/8/12/648
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spelling doaj-453ae096ccd34fd18e98ff05513a69622020-11-25T00:58:12ZengMDPI AGCatalysts2073-43442018-12-0181264810.3390/catal8120648catal8120648Theoretical Study on the Mechanism of Hydrogen Donation and Transfer for Hydrogen-Donor Solvents during Direct Coal LiquefactionHaigang Hao0Tong Chang1Linxia Cui2Ruiqing Sun3Rui Gao4College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, ChinaDepartment of Applied chemistry, Yuncheng University, Yuncheng 044000, ChinaCollege of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, ChinaCollege of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, ChinaCollege of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, ChinaAs a country that is poor in petroleum yet rich in coal, it is significant for China to develop direct coal liquefaction (DCL) technology to relieve the pressure from petroleum shortages to guarantee national energy security. To improve the efficiency of the direct coal liquefaction process, scientists and researchers have made great contributions to studying and developing highly efficient hydrogen donor (H-donor) solvents. Nevertheless, the details of hydrogen donation and the transfer pathways of H-donor solvents are still unclear. The present work examined hydrogen donation and transfer pathways using a model H-donor solvent, tetralin, by density functional theory (DFT) calculation. The reaction condition and state of the solvent (gas or liquid) were considered, and the specific elementary reaction routes for hydrogen donation and transfer were calculated. In the DCL process, the dominant hydrogen donation mechanism was the concerted mechanism. The sequence of tetralin donating hydrogen atoms was &#945;-H (C<sub>1</sub>&#8315;H) &gt; &#948;-H (C<sub>4</sub>&#8315;H) &gt; &#946;-H (C<sub>2</sub>&#8315;H) &gt; &#947;-H (C<sub>3</sub>&#8315;H). Compared to methyl, it was relatively hard for benzyl to obtain the first hydrogen atom from tetralin, while it was relatively easy to obtain the second and third hydrogen atoms from tetralin. Comparatively, it was easier for coal radicals to capture hydrogen atoms from the H-donor solvent than to obtain hydrogen atoms from hydrogen gas.https://www.mdpi.com/2073-4344/8/12/648direct coal liquefactionhydrogen donor solventhydrogen donation mechanismhydrogen transfer mechanismDFT calculation
collection DOAJ
language English
format Article
sources DOAJ
author Haigang Hao
Tong Chang
Linxia Cui
Ruiqing Sun
Rui Gao
spellingShingle Haigang Hao
Tong Chang
Linxia Cui
Ruiqing Sun
Rui Gao
Theoretical Study on the Mechanism of Hydrogen Donation and Transfer for Hydrogen-Donor Solvents during Direct Coal Liquefaction
Catalysts
direct coal liquefaction
hydrogen donor solvent
hydrogen donation mechanism
hydrogen transfer mechanism
DFT calculation
author_facet Haigang Hao
Tong Chang
Linxia Cui
Ruiqing Sun
Rui Gao
author_sort Haigang Hao
title Theoretical Study on the Mechanism of Hydrogen Donation and Transfer for Hydrogen-Donor Solvents during Direct Coal Liquefaction
title_short Theoretical Study on the Mechanism of Hydrogen Donation and Transfer for Hydrogen-Donor Solvents during Direct Coal Liquefaction
title_full Theoretical Study on the Mechanism of Hydrogen Donation and Transfer for Hydrogen-Donor Solvents during Direct Coal Liquefaction
title_fullStr Theoretical Study on the Mechanism of Hydrogen Donation and Transfer for Hydrogen-Donor Solvents during Direct Coal Liquefaction
title_full_unstemmed Theoretical Study on the Mechanism of Hydrogen Donation and Transfer for Hydrogen-Donor Solvents during Direct Coal Liquefaction
title_sort theoretical study on the mechanism of hydrogen donation and transfer for hydrogen-donor solvents during direct coal liquefaction
publisher MDPI AG
series Catalysts
issn 2073-4344
publishDate 2018-12-01
description As a country that is poor in petroleum yet rich in coal, it is significant for China to develop direct coal liquefaction (DCL) technology to relieve the pressure from petroleum shortages to guarantee national energy security. To improve the efficiency of the direct coal liquefaction process, scientists and researchers have made great contributions to studying and developing highly efficient hydrogen donor (H-donor) solvents. Nevertheless, the details of hydrogen donation and the transfer pathways of H-donor solvents are still unclear. The present work examined hydrogen donation and transfer pathways using a model H-donor solvent, tetralin, by density functional theory (DFT) calculation. The reaction condition and state of the solvent (gas or liquid) were considered, and the specific elementary reaction routes for hydrogen donation and transfer were calculated. In the DCL process, the dominant hydrogen donation mechanism was the concerted mechanism. The sequence of tetralin donating hydrogen atoms was &#945;-H (C<sub>1</sub>&#8315;H) &gt; &#948;-H (C<sub>4</sub>&#8315;H) &gt; &#946;-H (C<sub>2</sub>&#8315;H) &gt; &#947;-H (C<sub>3</sub>&#8315;H). Compared to methyl, it was relatively hard for benzyl to obtain the first hydrogen atom from tetralin, while it was relatively easy to obtain the second and third hydrogen atoms from tetralin. Comparatively, it was easier for coal radicals to capture hydrogen atoms from the H-donor solvent than to obtain hydrogen atoms from hydrogen gas.
topic direct coal liquefaction
hydrogen donor solvent
hydrogen donation mechanism
hydrogen transfer mechanism
DFT calculation
url https://www.mdpi.com/2073-4344/8/12/648
work_keys_str_mv AT haiganghao theoreticalstudyonthemechanismofhydrogendonationandtransferforhydrogendonorsolventsduringdirectcoalliquefaction
AT tongchang theoreticalstudyonthemechanismofhydrogendonationandtransferforhydrogendonorsolventsduringdirectcoalliquefaction
AT linxiacui theoreticalstudyonthemechanismofhydrogendonationandtransferforhydrogendonorsolventsduringdirectcoalliquefaction
AT ruiqingsun theoreticalstudyonthemechanismofhydrogendonationandtransferforhydrogendonorsolventsduringdirectcoalliquefaction
AT ruigao theoreticalstudyonthemechanismofhydrogendonationandtransferforhydrogendonorsolventsduringdirectcoalliquefaction
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