A fuel heat of vaporization (ΔH
vap) is a fundamental thermodynamic property
and an important parameter
for internal combustion engine design. The ΔH
vap value is measured with a newly developed vacuum thermogravimetric
analysis (VTGA) method. The technique is applicable to jet and diesel
range fuels. The measured values for the selected components in the
fuels agree with the literature values within a range of ±5%.
VTGA is a quick, cost-effective, and accurate method to measure the
ΔH
vap of renewable fuels. The ΔH
vap values for binary mixtures of fuels can
be simply estimated from the ΔH
vap values and mix ratio of the parents.
In this study, the characteristics
of the precipitated material
product of the blending of two crude oils are analyzed as a function
of aging time. In general, the deposits are enriched in asphaltenes
and waxes in comparison to the parent crude oils. They also contain
a significant amount of maltenes. The results also indicate that the
amount and composition of the deposit change as the deposit ages.
A decrease in the amount of the deposit is observed at shorter times,
but later, the deposit amount increases until it reaches a plateau
at longer times. During aging, the deposit becomes more hydrogen deficient
and richer in asphaltenes. Waxes in the deposit experience a decrease
in concentration at shorter times but an increase at longer times.
As the deposit ages, wax distributions shift to longer alkanes. These
changes in wax concentrations and distributions are reflected in the
wax appearance temperatures as well. Maltenes show the same temporal
behavior as waxes as the deposit ages.
Video recording of the manual version of the ASTM D445, Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity), effectively automated this method, resolved ergonomic concerns, reduced chemical exposure of an operator, drastically reduced probability of errors of the operator, significantly improved productivity, and simplified the analyst training process and work turnover. The accuracy of results is acceptable from the standpoint of the ASTM D445 method.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.