Application of Ethylene Tar as an Additive in Visbreaking of Petroleum Vacuum Residue

Abstract

The byproduct of ethylene tar has a high content of mono-, bi-, and polycyclic aromatic compounds, as well as cycloalkenes, including aromatic cycloalkenes. This paper evaluates the prospects of using ethylene tar as an additive in the visbreaking process of vacuum residue. A series of experiments on visbreaking of vacuum residue with additives of various refinery streams and ethylene tar were performed in a laboratory flow reactor. As a result of a comparative study of the composition of vacuum residue visbreaking products by different methods, it was shown that the use of ethylene tar compared with kerosene, light cycle oil, and heavy cycle oil allows an increased yield of the target product with a higher proportion of aromatic hydrocarbons. A comparative analysis of the characteristics of asphaltenes and resins of visbreaking products indicates a general trend of changes in the process of visbreaking vacuum residue with refinery streams and ethylene tar. A comparison of the colloidal instability index showed that the use of ethylene tar allows attainment of a more stable visbreaking product concerning refinery streams as additives.

Modified Technogenic Asphaltenes as Enhancers of the Thermal Conductivity of Paraffin

“…Probably, technogenic asphaltenes are represented by oligomeric forms (mainly dimeric) of aromatic structural units obtained as a result of condensation at the pyrolysis of mixed gasoline. Thus, the predominant aromatic compounds previously identified by us in distillate fractions (up to 350 ℃) of ET [ 26 ] were derivatives of phenanthrene, biphenyl, naphthalene, fluorine, and pyrene. It can be assumed that the heavy residue of ET (asphaltenes ET-A) is a mixture of the oligomeric forms of these aromatic compounds, as described in [ 28 ].…”

“…The complete characterization of ET (fractional composition, group hydrocarbon composition of distillate fractions, etc.) is presented in [ 26 ]. Technogenic asphaltenes, designated as “ET-A”, and petroleum asphaltenes, designated as “Petroleum-A”, were isolated by the IP 143 method from ET and crude oil from the Ashalchinskoye field (Russia), respectively.…”

“…However, on an industrial scale, ET is used mainly for the production of carbon black or as a component of boiler fuel. It should be noted that ET is a mixture of various compounds, predominantly aromatic [ 26 , 27 ], and is usually characterized by the content of saturated, aromatic, and polar compounds according to the IP 469 method and technogenic asphaltenes, a residue insoluble in heptane according to the IP 143 method. Thus, ET has great potential for the production of various carbon materials and can serve as a valuable source for the extraction of polycyclic aromatic compounds.…”

Unexpected Structural Effects on the Onset of Thermal Reactions of Aromatic Hydrocarbons

“…For example, atmospheric (330–360 °C) and vacuum (370–380 °C) distillations are maintained below 420 °C to minimize thermal cracking. Mild thermal cracking at 450–500 °C is required to reduce viscosity for visbreaking . More severe thermal cracking processes, such as coking, are typically at 475–520 °C.…”

“…Mild thermal cracking at 450−500 °C is required to reduce viscosity for visbreaking. 22 More severe thermal cracking processes, such as coking, are typically at 475−520 °C. The temperatures of hydrocracking or catalytic cracking can be decreased in the presence of catalysts (typically 380− 480 °C), although severe catalytic cracking at ∼535 °C is required in fluid catalytic cracking (FCC).…”