Procedure for Measuring the Weight Fraction of Products of Catalytic Pyrolysis of Ethylbenzene

2019 ◽  
Vol 19 (3) ◽  
pp. 187-192
Author(s):  
E. Yu. Yakovleva ◽  
Yan Shanshan ◽  
Z. P. Pai

A capillary column with functionalized poly(1-trimethylsilyl-1-propyne) (PTMSP/N2O) was proposed to use for detecting products of catalytic pyrolysis of ethylbenzene. The capillary PTMSP/N2O column separated selectively light C1–C2 (methane, ethane, ethylene, acetylene) and aromatic (benzene, toluene, ethylbenzene, styrene) hydrocarbons. A procedure for gas-phase measuring weight fractions of light C1–C2 and aromatic hydrocarbons was developed. The analytical measurement range was 2.9·10–8 to 1.2·10–1 mg/mL for light C1–C2 components and 3.5·10–11 to 4.0·10–3 mg/mL for liquid components. The analytical error margin at repetition ranged from 1.9 % to 4.7 %.

2019 ◽  
Vol 21 (14) ◽  
pp. 3802-3806 ◽  
Author(s):  
Homer C. Genuino ◽  
Inouk Muizebelt ◽  
André Heeres ◽  
Niels J. Schenk ◽  
Jos G. M. Winkelman ◽  
...  

Catalytic pyrolysis of crude glycerol over a shaped H-ZSM-5 zeolite catalyst with (partial) recycling of the product oil was studied with the incentive to improve benzene, toluene, and xylene (BTX) yields.


2017 ◽  
Vol 68 (1) ◽  
pp. 116-120
Author(s):  
Iuliean Vasile Asaftei ◽  
Neculai Catalin Lungu ◽  
Lucian Mihail Birsa ◽  
Ioan Gabriel Sandu ◽  
Laura Gabriela Sarbu ◽  
...  

The conversion of n-heptanes into aromatic hydrocarbons benzene, toluene and xylenes (BTX), by the chromatographic pulse method in the temperature range of 673 - 823K was performed over the HZSM-5 and Ag-HZSM-5 zeolites modified by ion exchange with AgNO3 aqueous solutions. The catalysts, HZSM-5 (SiO2/Al2O3 = 33.9), and Ag-HZSM-5 (Ag1-HZSM-5 wt. % Ag1.02, Ag2-HZSM-5 wt. % Ag 1.62; and Ag3-HZSM-5 wt. % Ag 2.05 having different acid strength distribution exhibit a conversion and a yield of aromatics depending on temperature and metal content. The yield of aromatic hydrocarbons BTX appreciably increased by incorporating silver cations Ag+ into HZSM-5.


2017 ◽  
Vol 23 (38) ◽  
pp. 9018-9021 ◽  
Author(s):  
Pierre-Emmanuel Alexandre ◽  
Alexander Schwenger ◽  
Wolfgang Frey ◽  
Clemens Richert

In the first paper of this series (Burgoyne 1937) the kinetics of the isothermal oxidation above 400° C of several aromatic hydrocarbons was studied. The present communication extends this work to include the phenomena of ignition in the same temperature range, whilst the corresponding reactions below 400° C form the subject of further investigations now in progress. The hydrocarbons at present under consideration are benzene, toluene, ethylbenzene, n -propylbenzene, o-, m - and p -xylenes and mesitylene.


1981 ◽  
Vol 59 (15) ◽  
pp. 2412-2416 ◽  
Author(s):  
John A. Stone ◽  
Margaret S. Lin ◽  
Jeffrey Varah

The reactivity of the dimethylchloronium ion with a series of aromatic hydrocarbons has been studied in a high pressure mass spectrometer ion source using the technique of reactant ion monitoring. Benzene is unreactive but all others, from toluene to mesitylene, react by CH3+ transfer to yield σ-bonded complexes. The relative rate of reaction increases with increasing exothermicity in line with current theories of nucleophilic displacement reactions.


1989 ◽  
Vol 42 (10) ◽  
pp. 1655 ◽  
Author(s):  
FP Larkins ◽  
AZ Khan

Some basic thermodynamic parameters such as Gibbs free energies, enthalpies of reactions and equilibrium compositions of products from the pyrolysis and partial oxidation of methane to higher hydrocarbons in the gas phase have been determined within a consistent framework for the temperature range 800-1500 K and the pressure range 0.1-3 MPa , by using the CSIRO-SGTE THERMODATA system. It has been established that the pyrolysis of methane to higher hydrocarbons, e.g. acetylene, ethylene, ethane, prop-1-ene, propane, benzene, toluene, naphthalene, 1-methylnaphthalene and 2-methylnaphthalene, considered as separate reactions, is a highly endothermic reaction with the Gibbs free energies for the individual reactions being positive until 1300 K. The aromatics are thermodynamically most favoured with the equilibrium yields increasing with temperature. Addition of O2 lowers the heats of synthesis and the free energies for methane conversion but no enhancement in the equilibrium yields of hydrocarbons is observed. When solid carbon is allowed, it is the dominant product in all cases with the equilibrium yields for all hydrocarbons becoming negligible. Increasing the pressure at a particular temperature has more effect on the lowering of the equilibrium conversion of methane than on the suppression of solid carbon. Such data are valuable for understanding the conversion limits for methane into higher hydrocarbons.


2001 ◽  
Vol 183 (18) ◽  
pp. 5441-5444 ◽  
Author(s):  
Hikaru Suenaga ◽  
Mariko Mitsuoka ◽  
Yuko Ura ◽  
Takahito Watanabe ◽  
Kensuke Furukawa

ABSTRACT Biphenyl dioxygenase (Bph Dox) catalyzes the initial oxygenation of biphenyl and related compounds. Bph Dox is a multicomponent enzyme in which a large subunit (encoded by the bphA1 gene) is significantly responsible for substrate specificity. By using the process of DNA shuffling of bphA1 of Pseudomonas pseudoalcaligenes KF707 and Burkholderia cepaciaLB400, a number of evolved Bph Dox enzymes were created. Among them, anEscherichia coli clone expressing chimeric Bph Dox exhibited extremely enhanced benzene-, toluene-, and alkylbenzene-degrading abilities. In this evolved BphA1, four amino acids (H255Q, V258I, G268A, and F277Y) were changed from the KF707 enzyme to those of the LB400 enzyme. Subsequent site-directed mutagenesis allowed us to determine the amino acids responsible for the degradation of monocyclic aromatic hydrocarbons.


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