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

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 648 ◽  
Author(s):  
Haigang Hao ◽  
Tong Chang ◽  
Linxia Cui ◽  
Ruiqing Sun ◽  
Rui Gao
Keyword(s):  
Density Functional ◽  
Hydrogen Gas ◽  
Hydrogen Donor ◽  
Coal Liquefaction ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Donor Solvent ◽  
National Energy Security ◽  
Liquefaction Process ◽  
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, 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 α-H (C1–H) > δ-H (C4–H) > β-H (C2–H) > γ-H (C3–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.

scholarly journals Transformation Characteristics of Hydrogen-Donor Solvent Tetralin in the Process of Direct Coal Liquefaction

2019 ◽  
Vol 7 ◽  
Author(s):  
Hai-zhou Chang ◽  
Jun-qi Li ◽  
Shuai Du ◽  
Kai-yuan Shen ◽  
Qun Yang ◽  
...  
Keyword(s):  
Hydrogen Donor ◽  
Coal Liquefaction ◽  
Donor Solvent ◽  
Direct Coal Liquefaction

Crystal structure of pomalidomide Form I, C13H11N3O4

2021 ◽  
pp. 1-6
Author(s):  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Density Functional ◽  
Double Layers ◽  
Carbonyl Groups ◽  
Hydrogen Atoms ◽  
Powder Diffraction File ◽  
Functional Theory ◽  
Amine Hydrogen

The crystal structure of pomalidomide Form I has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Pomalidomide Form I crystallizes in the space group P-1 (#2) with a = 7.04742(9), b = 7.89103(27), c = 11.3106(6) Å, α = 73.2499(13), β = 80.9198(9), γ = 88.5969(6)°, V = 594.618(8) Å3, and Z = 2. The crystal structure is characterized by the parallel stacking of planes parallel to the bc-plane. Hydrogen bonds link the molecules into double layers also parallel to the bc-plane. Each of the amine hydrogen atoms acts as a donor to a carbonyl group in an N–H⋯O hydrogen bond, but only two of the four carbonyl groups act as acceptors in such hydrogen bonds. Other carbonyl groups participate in C–H⋯O hydrogen bonds. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™ (PDF®).

Coal feed flexibility in the Exxon Donor Solvent coal liquefaction process

Fuel ◽  
1981 ◽  
Vol 60 (9) ◽  
pp. 788-794 ◽  
Author(s):  
John W. Taunton ◽  
K.L. Trachte ◽  
R.D. Williams
Keyword(s):  
Coal Liquefaction ◽  
Donor Solvent ◽  
Liquefaction Process

scholarly journals Dumbbell configuration of silicon adatom defects on silicene nanoribbons

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Huynh Anh Huy ◽  
Quoc Duy Ho ◽  
Truong Quoc Tuan ◽  
Ong Kim Le ◽  
Nguyen Le Hoai Phuong
Keyword(s):  
Magnetic Properties ◽  
Band Gap ◽  
Density Functional ◽  
Spin Moment ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Electronic And Magnetic Properties ◽  
Spin Degeneracy ◽  
Silicene Nanoribbons ◽  
Formation Energies

AbstractUsing density functional theory (DFT), we performed theoretical investigation on structural, energetic, electronic, and magnetic properties of pure armchair silicene nanoribbons with edges terminated with hydrogen atoms (ASiNRs:H), and the absorptions of silicon (Si) atom(s) on the top of ASiNRs:H. The calculated results show that Si atoms prefer to adsorb on the top site of ASiNRs:H and form the single- and/or di-adatom defects depending on the numbers. Si absorption defect(s) change electronic and magnetic properties of ASiNRs:H. Depending on the adsorption site the band gap of ASiNRs:H can be larger or smaller. The largest band gap of 1 Si atom adsorption is 0.64 eV at site 3, the adsorption of 2 Si atoms has the largest band gap of 0.44 eV at site 1-D, while the adsorption at sites5 and 1-E turn into metallic. The formation energies of Si adsorption show that adatom defects in ASiNRs:H are more preferable than pure ASiNRs:H with silicon atom(s). 1 Si adsorption prefers to be added on the top site of a Si atom and form a single-adatom defect, while Si di-adatom defect has lower formation energy than the single-adatom and the most energetically favorable adsorption is at site 1-F. Si adsorption atoms break spin-degeneracy of ASiNRs:H lead to di-adatom defect at site 1-G has the highest spin moment. Our results suggest new ways to engineer the band gap and magnetic properties silicene materials.

scholarly journals Basic study of extractive liquefaction of coal. II. Coal liquefaction with the recycled hydrogen donor solvent.

1985 ◽  
Vol 64 (1) ◽  
pp. 26-35
Author(s):  
Ryohei MINAMI ◽  
Tamio SHIRAFUJI ◽  
Mikio KATO ◽  
Yoshihiko SUNAMI
Keyword(s):  
Hydrogen Donor ◽  
Coal Liquefaction ◽  
Basic Study ◽  
Donor Solvent

First-Principles Study of Interaction of Lithium Atoms with (3, 3) Carbon Nanotubes

2014 ◽  
Vol 687-691 ◽  
pp. 4311-4314 ◽  
Author(s):  
Shun Fu Xu ◽  
Ling Min Li
Keyword(s):  
Carbon Nanotubes ◽  
First Principles ◽  
Density Functional ◽  
Vacancy Defect ◽  
Single Wall Carbon Nanotubes ◽  
Generalized Gradient ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Vacancy Defects ◽  
Adsorption Mechanisms

In this paper, we have employed first-principles calculations to investigate the adsorption mechanisms of one lithium atom on the sidewalls of 1/2/3 H-adsorbed indefective/defective (3, 3) single-wall carbon nanotubes (CNTs) which have vacancy defects. Our calculations are performed within density functional theory (DFT) under the generalized gradient approximation (GGA) of Perdew, Burke, and Ernzerhof (PBE).Our results show that the lithium atoms strongly binds to the H-adsorbed (3, 3) nanotube. Lithium atoms can chemically adsorb on (3, 3) nanotube with the vacancy defect (MVD) without any energy barrier. The lithium adsorption will enhance the electrical conductivity of the nanotube. Further more, the structure of the (3, 3) nanotube with the MVD and hydrogen atoms will become more stable after the three kinds of lithium adsorption.

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