Chemistry and Technology of Fuels and Oils, Vol. 37, No. 3, 2001
SOLVENT DEHYDRATION AND SEPARATION OF NATIVE ASPHALT
A. Yu. Kopylov, V. G. Kozin, and I. Sh. Khusnutdinov UDC 665.63.404
Kazan’ State Technological University. Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 3,
pp. 11 – 14, May – June, 2001.
2001Plenum Publishing Corporation
A combined process for dehydration, deasphalting, and acetone fractionation of Ashal’chinsk native asphalt
was developed and investigated. Technology was proposed for combined solvent preparation and separation
of natural asphalt and the basic characteristics of the process were determined. The technical and economic
indexes of the proposed and traditional technologies were compared.
With the depletion of traditional crude oil reserves, increasing attention is being focused on alternative
sources of hydrocarbon feedstock. In particular, native asphalts (NA) are promising stock for production of
fuels, high-quality lube oils, and many petrochemical products. However, in the traditional approach to their
separation, the technical and economic indexes of the process are significantly reduced.
The potentials for use of NA are primarily related to the high content of resins and asphaltenes (RA) and
lube oil cuts whose composition and structure allow using them as feedstock for production of high-quality asphalt
materials and oils for different applications. However, in processing with the traditional scheme, the valuable RA
initially deposited in NA by nature are not separated; they are synthesized by the complicated, energy-intensive
process of oxidation of vacuum resids.
The low (of the order of 300°C) thermal stability threshold of NA causes decomposition of RA during
fractionation and combined with the low content of light cuts, this worsens the conditions and technical and
economic indexes of operation of the fractionation units . To increase the degree of extraction of valuable lube
oil components from NA, it is necessary to use methods with a low thermal effect on the feedstock.
The problem of preparing NA for processing involves its dehydration. The high content of native
emulsifiers — RA, and the high density and viscosity cause the formation of stable water—asphalt emulsions.
Traditional thermochemical methods of dehydration are not always effective for this reason . To attain the
required degree of dehydration, these methods are used in combination with the addition of a hydrocarbon solvent,
Residual content (wt. %) of water in NA after dehydration with a demulsifier
Diproxamine 157 Reapon 4B Disolvan 4411 Dowfax
30 23.9 – 5.1
26.7 19.3 – 3.7
17.0 1.3 – 0.7
7.9 1.4 – 0.5
16.8 9 10.5 12
15 5.4 8.4 9.5
12.5 4.6 7.3 5.5