Deposit Formation in Hydrocarbon Fuels

1983 ◽  
Vol 105 (1) ◽  
pp. 59-65 ◽  
Author(s):  
R. Roback ◽  
E. J. Szetela ◽  
L. J. Spadaccini
Keyword(s):  
Thermal Stability ◽  
Carbon Deposition ◽  
Tube Wall ◽  
Hydrocarbon Fuels ◽  
Wall Material ◽  
Test Apparatus ◽  
Deposit Formation ◽  
Deposition Rates ◽  
Commercial Grade ◽  
Inside Wall

A high-pressure fuel coking test apparatus was designed and developed and was used to evaluate thermal decomposition (coking) limits and carbon deposition rates in heated copper tubes for two hydrocarbon fuels, RP-1 and commercial-grade propane. Tests were also conducted using JP-7 and chemically-pure propane as being representative of more refined cuts of the baseline fuels. A parametric evaluation of fuel thermal stability was performed at pressures of 136 atm to 340 atm, bulk fuel velocities in the range 6–30 m/s and tube wall temperatures in the range 422–811 K. In addition, the effect of the inside wall material on deposit formation was evaluated in selected tests which were conducted using nickel-plated tubes. The results of the tests indicated that substantial deposit formation occurs with RP-1 fuel at wall temperatures between 600 and 800 K, with peak deposit formation occurring near 700 K. No improvements were obtained when deoxygenated JP-7 fuel was substituted for RP-1. The carbon deposition rates for the propane fuels were generally higher than those obtained for either of the kerosene fuels at any given wall temperature. Finally, plating the inside wall of the tubes with nickel was found to significantly reduce carbon deposition rates for RP-1 fuel.

Deposit Formation in Hydrocarbon Fuels

1982 ◽  
Author(s):  
R. Roback ◽  
E. J. Szetela ◽  
L. J. Spadaccini
Keyword(s):  
Thermal Stability ◽  
Carbon Deposition ◽  
Tube Wall ◽  
Hydrocarbon Fuels ◽  
Wall Material ◽  
Test Apparatus ◽  
Deposit Formation ◽  
Deposition Rates ◽  
Commercial Grade ◽  
Inside Wall

A high pressure fuel coking test apparatus was designed and developed and was used to evaluate thermal decomposition (coking) limits and carbon deposition rates in heated copper tubes for two hydrocarbon fuels, RP-1 and commercial-grade propane. Tests were also conducted using JP-7 and chemically-pure propane as being representative of more refined cuts of the baseline fuels. A parametric evaluation of fuel thermal stability was performed at pressures of 136 atm to 340 atm, bulk fuel velocities in the range 6–30 m/s and tube wall temperatures in the range 422–811 K. In addition, the effect of the inside wall material on deposit formation was evaluated in selected tests which were conducted using nickel-plated tubes. The results of the tests indicated that substantial deposit formation occurs with RP-1 fuel at wall temperatures between 600 and 800 K, with peak deposit formation occurring near 700 K. No improvements were obtained when deoxygenated JP-7 fuel was substituted for RP-1. The carbon deposition rates for the propane fuels were generally higher than those obtained for either of the kerosene fuels at any given wall temperature. Finally, plating the inside wall of the tubes with nickel was found to significantly reduce carbon deposition rates for RP-1 fuel.

scholarly journals Temperature Effects on Fuel Thermal Stability

1991 ◽  
Author(s):  
J. S. Chin ◽  
A. H. Lefebvre ◽  
F. T.-Y. Sun
Keyword(s):  
Thermal Stability ◽  
Wall Temperature ◽  
Tube Wall ◽  
Fuel Temperature ◽  
Deposition Rates ◽  
Heated Tube ◽  
Increase With Increase ◽  
Before And After ◽  
Tube Wall Temperature ◽  
The Impact

The thermal stability characteristics of four kerosine-type fuels are examined using a heated-tube apparatus which allows independent control of fuel pressure, fuel temperature, tube-wall temperature, and fuel flow rate. It is a closed loop system, and fuet flows through the heated tube for periods ranging from 6 to 22 hrs. The deposition rates of carbon on the tube walls are measured by weighing the tube before and after each test. The results obtained show that tube-wall and fuel temperatures both have a marked influence on deposition rates, the impact of fuel temperature being stronger than that of wall temperature. It is also found that deposition rates increase continuously with increases in tube-wall temperature. This finding contradicts the results of previous studies which had led to the conclusion that deposition rates increase with increase in wall temperature up to a certain value beyond which any further increase in wall temperature causes the deposition rate to decline.

Temperature Effects on Fuel Thermal Stability

1992 ◽  
Vol 114 (2) ◽  
pp. 353-358 ◽  
Author(s):  
J. S. Chin ◽  
A. H. Lefebvre ◽  
F. T.-Y. Sun
Keyword(s):  
Thermal Stability ◽  
Wall Temperature ◽  
Tube Wall ◽  
Fuel Temperature ◽  
Deposition Rates ◽  
Heated Tube ◽  
Increase With Increase ◽  
Before And After ◽  
Tube Wall Temperature ◽  
The Impact

The thermal stability characteristics of four kerosine-type fuels are examined using a heated-tube apparatus that allows independent control of fuel pressure, fuel temperature, tube-wall temperature, and fuel flow rate. It is a closed loop system, and fuel flows through the heated tube for periods ranging from 6 to 22 h. The deposition rates of carbon on the tube walls are measured by weighing the tube before and after each test. The results obtained show that tube-wall and fuel temperatures both have a marked influence on deposition rates, the impact of fuel temperature being stronger than that of wall temperature. It is also found that deposition rates increase continuously with increases in tube-wall temperature. This finding contradicts the results of previous studies, which had led to the conclusion that deposition rates increase with increase in wall temperature up to a certain value, beyond which any further increase in wall temperature causes the deposition rate to decline.

The growth of the pollen tube wall in Oenothera organensis

1975 ◽  
Vol 18 (3) ◽  
pp. 519-532
Author(s):  
H.G. Dickinson ◽  
J. Lawson
Keyword(s):  
Pollen Tube ◽  
Tube Wall ◽  
Wall Material ◽  
Fibrillar Material ◽  
Stage Of Development ◽  
Large Numbers ◽  
Membrane Bound ◽  
Pollen Tube Wall ◽  
Different Sources ◽  
Dictyosome Vesicles

The growth of the pollen tube wall of Oenothera is effected by the expulsion of fibrillar material from the cytoplasm into the developing wall. This material may also be seen in the cytoplasm, contained in membrane-bound vesicles. It is not clear how the content of the vesicles is discharged, but it appears not to involve the participation of microtubules. The source of the cytoplasmic fibrillar bodies depends upon the stage of development of the pollen tube. The earilest growth is derived from the inclusion into the wall of vesicles containing pre-formed materials present in the grain on pollination. During the next stage of growth the wall is derived from the content of double-membraned inclusions also present in the pollen. The content of the former vesicles is not so similar to the wall as the latter, but intermediates between the 2 types of vesicle may be seen in the cytoplasm, indicating that the former are formed from the latter. Most of the tube wall is derived from the products of dictyosomes in the pollen grain or tube. These dicytosomes are few in number and they must be exceedingly active. This, and the observation that dictyosome vesicles are frequently associated with banked complexes of mitochondria, indicates that some steps in the metabolism of the vesicular content, perhaps phosphorylation, take place distant from the dicytosomes. These different sources of fibrillar material presumably permit the rapid starting of tube growth, without any attendant metabolism. However, it would be impossible to include enough pre-formed wall material in the grain to enable the full growth of the tube, so once started, it seems that the tube then relies on the elaboration of simple reserves for the contruction of its wall. These reserves are likely to be held in the pollen, and may be the large numbers of starch grains characteristic of the pollen cytoplasm.

THERMAL STABILITY OF HYDROCARBON FUELS

1961 ◽  
Author(s):  
G. D. KITTREDGE ◽  
W. L. STREETS ◽  
REX RATCHFORD
Keyword(s):  
Thermal Stability ◽  
Hydrocarbon Fuels ◽  
Thermal Stability Of

Stability of Nickel-based Cermet Anode for Carbon Deposition during Cell Operation with Slightly Humidified Gaseous Hydrocarbon Fuels

2019 ◽  
Vol 7 (1) ◽  
pp. 1661-1668 ◽  
Author(s):  
Katsuhiko Yamaji ◽  
Haruo Kishimoto ◽  
Xiong Yueping ◽  
Teruhisa Horita ◽  
Natsuko Sakai ◽  
...  
Keyword(s):  
Carbon Deposition ◽  
Hydrocarbon Fuels ◽  
Gaseous Hydrocarbon

scholarly journals Catalytic carbon deposition-oxidation over Ni, Fe and Co catalysts: A new indirect route to store and transport gas hydrocarbon fuels

2013 ◽  
Vol 32 ◽  
pp. 58-61 ◽  
Author(s):  
Patrícia E.F. Oliveira ◽  
Leandro P. Ribeiro ◽  
Marcelo G. Rosmaninho ◽  
José D. Ardisson ◽  
Anderson Dias ◽  
...  
Keyword(s):  
Carbon Deposition ◽  
Hydrocarbon Fuels ◽  
Co Catalysts ◽  
Indirect Route
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