2 research outputs found
Sensitivity of Asphaltene Aggregation toward the Molecular Architecture under Desalting Thermodynamic Conditions
The challenges faced
by the oil and shale industries include the
comprehension of the physical–chemical behavior of heavy-weight
phases. These phases have a high tendency to aggregate, mainly as
a result of the presence of asphaltenes, the composition of which
has been fairly unclear up to now. The chemical composition of this
phase is one of the driving forces behind the physical–chemical
behavior in oil, and the structure–property relations of these
systems are key in the development of improved refining techniques,
including the design of new catalysts. In this paper, the aggregation
of asphaltene molecules is studied with regard to molecular architecture
and variations in the size of the aromatic core and lateral chain
length using classical molecular dynamics simulations. How these characteristics
are impacted by the temperature and pressure is also examined. This
analysis provides a general overview of the factors that have the
strongest impact on the formation and stability of nanoaggregates
and clusters of nanoaggregates
Characterization and Comparison of Trace Metal Compositions in Natural Gas, Biogas, and Biomethane
Biogases
are a renewable energy source intended to facilitate the
energy transition from natural gas in various domains such as heat
and electricity production. The composition of biogas and biomethane
is well-known in terms of major compounds, which include methane,
carbon dioxide, and hydrogen sulfide. However, the trace element composition
of these gases is poorly documented. For the first time, trace metal
composition of biomethane produced from agricultural waste and biogas
generated at a nonhazardous waste landfill and intended to produce
electricity by cogeneration is presented in this work and is compared
to the trace metal composition of natural gas. A dedicated high-pressure
bubbling sampler was used to sample gas at different operating pressures
ranging from 1 to 40 bar. Multiple wide-ranging screenings of metals
and metalloids were conducted regarding the elements Se, Cd, Ni, Sb,
As, Zn, Pb, Sn, Cr, Ba, Al, V, Mo, Cu, and Ag. The metal concentrations
in the sampled natural gas and biomethane were found to be at the
same order of magnitude and ranged from 10<sup>–1</sup> to
10<sup>2</sup> ng/N m<sup>3</sup>, although some differences in the
details were observed. Compared with the metals in those two gases,
the metals in the biogas were at higher concentrations, ranging from
1 to 10<sup>3</sup> ng/N m<sup>3</sup>