Studies on the thermal coking of bitumen. I. The use of pyrene-d10 as a probe for evaluating the extent of hydrogen shuttling reaction

1991 ◽  
Vol 69 (1) ◽  
pp. 116-120 ◽  
Author(s):  
M. J. Kirk ◽  
T. S. Sorensen
Keyword(s):  
Free Radicals ◽  
Key Words ◽  
Hydrogen Exchange ◽  
Solvent Free ◽  
Hydrogen Donor ◽  
Organic Reactions ◽  
Hydrogen Atoms ◽  
Donor Solvent ◽  
Key Words Bitumen

The organic reactions that take place during the thermal coking of bitumen are extremely complex and deep-seated, but obviously hydrogen atoms originally attached to carbons that form coke will have moved to a new carbon site (net addition of hydrogen, resulting in upgraded bitumen). Accompanying this process, one expects some general hydrogen shuttling between non-coking molecules. This paper describes an approach to determing the extent of this latter process by the addition of a small amount of perdeuterated pyrene to the bitumen prior to the coking operation. The in situ pyrene functions as in indicator, allowing one to establish the extent and other mechanistic details of the "hydrogen donor" reactions that take place during coking. There is no indication that the pyrene substantially modifies the normal course of the reaction, hence the analogy to an indicator. Key words: bitumen coking, pyrene, hydrogen exchange, donor solvent, free radicals.

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.

Efficiency of diagnosis and treatment non-invasive and microinvasive sgamous cell cervical cancer

2020 ◽  
pp. 71-74
Author(s):  
M.M. Melnyk ◽  
◽  
S.V. Nespradko ◽  
I.V. Goncharuk ◽  
M.V. Marchenko ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Key Words ◽  
National Cancer Institute ◽  
Reproductive Function ◽  
Diagnosis And Treatment ◽  
Non Invasive ◽  
Corpus Uteri ◽  
Complex Program ◽  
Early Cervical Cancer

The objective: analyse the effectiveness of diagnosis and treatment for early cervical cancer. Materials and methods. Analysed 107 cases of women’s disease on CIN ІІІ, cancer in situ, they were on treatment in National cancer institute and Kyiv dictrict cancer dispensary from 2010 till 2015 years. Results. Diagnosed percent relapse CIN ІІІ, cancer in situ contain 4.57% uninvasive and invasive form – 0.94%. Conclusion. According diagnostic CIN ІІ and CIN ІІІ is recommended to do treatment conization and dynamic dispensary observation. Are making complex program of infection HPV16, 18. In appering of margins resection some elements of tumor after wider conization by forms of cancer in situ. Many of expansive burns in cervical glands, in making of reproductive function, going disease (nodel leiomyoma of corpus uteri etc). In perspective is accept the notion of looking after and screening research of considering infection HPV16, 18 on CIN І, CIN ІІ. Key words: cervical cancer, сancer in situ, CIN І–ІІІ, diagnostic, treatment, conization.

In-situ low temperature cleaning of silicon surfaces using hydrogen atoms

Vacuum ◽  
1995 ◽  
Vol 46 (7) ◽  
pp. 667-672 ◽  
Author(s):  
A Crossley ◽  
C.J. Sofield ◽  
S Sugden ◽  
R Clampitt ◽  
C Bradley
Keyword(s):  
Low Temperature ◽  
Silicon Surfaces ◽  
Hydrogen Atoms

Hydrotreating of Hydrochloric Acid Lignin in a Hydrogen-Donor Solvent

1982 ◽  
Vol 2 (1) ◽  
pp. 17-31 ◽  
Author(s):  
Tor P. Schultz ◽  
Raymond J. Preto ◽  
J. Lynn Pittman ◽  
Irving S. Goldstein
Keyword(s):  
Hydrochloric Acid ◽  
Hydrogen Donor ◽  
Donor Solvent

In situ estimation of the coefficient of consolidation in clays

1990 ◽  
Vol 27 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Mohammed G. Kabir ◽  
Alan J. Lutenegger
Keyword(s):  
Key Words ◽  
Pore Pressure ◽  
Reference Values ◽  
Time Factors ◽  
In Situ Tests ◽  
Coefficient Of Consolidation ◽  
Oedometer Test ◽  
Undisturbed Samples ◽  
Oedometer Tests

An investigation was conducted to demonstrate the applicability of cylindrical piezocone and flat piezoblade tests for providing reliable estimates of the coefficient of consolidation in clays. Coefficients of consolidation were calculated from piezocone dissipation tests for different degrees of consolidation using theoretical time factors to provide a comparison with laboratory oedometer tests. Three techniques were developed to calculate the coefficient of consolidation from piezoblade dissipation tests. Results from in situ pore pressure dissipation tests were compared with laboratory oedometer tests performed on undisturbed samples oriented in both the vertical and horizontal directions, to provide reference values of cv and ch. The results of investigations conducted at several clay sites are presented. Key words: in situ tests, piezocone, piezoblade, coefficient of consolidation, oedometer test, clays.

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
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