RADIATIVE PROPERTIES OF GASEOUS HYDROCARBONS AND THEIR MIXTURES
Rubrics: 2. CHEMICAL TECHNOLOGY
Authors:
1.
NHTI KNITU
2.
NHTI FGBOU VPO «KNITU»
3.
Nizhnekamskiy himiko-tehnologicheskiy institut
4.
NHTI FGBOU VPO «KNITU»
5.
Kazan National Research Technological University
(Department of Processes and Devices of Chemical Technologies, Laboratory assistant)
employee from 01.01.2025 until now
Kazan State Technological University
student from 01.01.2023 until now
Kazan, Kazan, Russian Federation
employee from 01.01.2025 until now
Kazan State Technological University
student from 01.01.2023 until now
Kazan, Kazan, Russian Federation
Type:
Article
Pages:
from 125
to 129
Status:
Published
Received:
14.01.2026
Accepted:
26.02.2026
Published:
05.04.2026
Language:
Russian
Keywords:
GASEOUS HYDROCARBON MIXTURES, THERMAL EMISSIVITY, SPECTRAL ABSORPTION BANDS, GRAYSCALE APPROXIMATION
Abstract:
The functional dependence of the thermal emissivity of ethane, propane, butane, ethylene, propylene, butylenes, and isobutylene on temperature, pressure, and the thickness of the radiating gas layer is presented. The integral thermal emissivity coefficients of these gaseous hydrocarbons were studied previously. The functional dependence of the thermal emissivity of hydrocarbons on temperature is assumed to be linear, and on pressure and the gas layer thickness, exponential, i.e., in the form: ε T,P,L = A+BT P K L m . The indices K and m are determined by the least squares method. The minimum total squared deviations S for all experimental points are considered at a single specific temperature T. However, it should be noted that the resulting functional dependence is based on experimental values, not on the physical laws of radiation processes, so extrapolating it beyond the experimental limits is not advisable. The integral thermal emissivity coefficients of binary and ternary mixtures were measured: ethane + butanes, propane + butylenes, ethane + propylene, propane + isobutylene, propane + butane, propylene + butylenes, ethylene + propylene + butylenes, and ethane + propylene + butylenes. The absolute method was used to measure the thermal emissivity coefficients of the mixtures at a temperature of 673 K in a partial pressure range from 0.004 to 0.1 MPa. It was found that the thermal emissivity coefficient of the hydrocarbon mixture is always lower than the sum of the individual thermal emissivity coefficients of the pure gaseous hydrocarbons. This is due to the overlap of the spectral absorption bands of hydrocarbons, as they all have a number of bands caused by similar vibration modes. When calculating the thermal emissivity of a hydrocarbon mixture, it is recommended to use a gray-scale approximation, taking into account a correction factor. A comparison of the experimentally obtained ε cm E values and the calculated ε cm P values according to equation (12) shows that the discrepancy between them, = ε cm E - ε cm P ε cm E ∙100% , is within 10% for some mixtures and reaches 25% for others. These deviations depend on the degree of overlap of the spectral bands. To determine a more accurate correction for the overlap of hydrocarbon absorption bands, spectral studies are necessary, which would take into account the influence of temperature, the relative content of components in the mixture, and the optical thickness of the gas mixture layer.
The functional dependence of the thermal emissivity of ethane, propane, butane, ethylene, propylene, butylenes, and isobutylene on temperature, pressure, and the thickness of the radiating gas layer is presented. The integral thermal emissivity coefficients of these gaseous hydrocarbons were studied previously. The functional dependence of the thermal emissivity of hydrocarbons on temperature is assumed to be linear, and on pressure and the gas layer thickness, exponential, i.e., in the form: ε T,P,L = A+BT P K L m . The indices K and m are determined by the least squares method. The minimum total squared deviations S for all experimental points are considered at a single specific temperature T. However, it should be noted that the resulting functional dependence is based on experimental values, not on the physical laws of radiation processes, so extrapolating it beyond the experimental limits is not advisable. The integral thermal emissivity coefficients of binary and ternary mixtures were measured: ethane + butanes, propane + butylenes, ethane + propylene, propane + isobutylene, propane + butane, propylene + butylenes, ethylene + propylene + butylenes, and ethane + propylene + butylenes. The absolute method was used to measure the thermal emissivity coefficients of the mixtures at a temperature of 673 K in a partial pressure range from 0.004 to 0.1 MPa. It was found that the thermal emissivity coefficient of the hydrocarbon mixture is always lower than the sum of the individual thermal emissivity coefficients of the pure gaseous hydrocarbons. This is due to the overlap of the spectral absorption bands of hydrocarbons, as they all have a number of bands caused by similar vibration modes. When calculating the thermal emissivity of a hydrocarbon mixture, it is recommended to use a gray-scale approximation, taking into account a correction factor. A comparison of the experimentally obtained ε cm E values and the calculated ε cm P values according to equation (12) shows that the discrepancy between them, = ε cm E - ε cm P ε cm E ∙100% , is within 10% for some mixtures and reaches 25% for others. These deviations depend on the degree of overlap of the spectral bands. To determine a more accurate correction for the overlap of hydrocarbon absorption bands, spectral studies are necessary, which would take into account the influence of temperature, the relative content of components in the mixture, and the optical thickness of the gas mixture layer.
Keywords:
GASEOUS HYDROCARBON MIXTURES, THERMAL EMISSIVITY, SPECTRAL ABSORPTION BANDS, GRAYSCALE APPROXIMATION
GASEOUS HYDROCARBON MIXTURES, THERMAL EMISSIVITY, SPECTRAL ABSORPTION BANDS, GRAYSCALE APPROXIMATION
