Air-treated propane-precipitated asphalt
AssigneeExxon Research & Engineering Co.
InventorsDominick Clementoni, Luke W. Corbett
Life of this patent
Estimating the term…
Abstract
Propane-precipitated asphalt is contacted with a stream of air at 200.degree. C. and above to increase the softening point of the asphalt. The resulting asphalt base, having a softening point of about 65.degree.-300.degree. C., is then blended with 5-60 weight percent liquid sulfur-treated petroleum fraction, having an equivalent atmospheric boiling point range of 370.degree.-500.degree. C., to yield paving grade quality asphalt cement composition.
Claims13
A process for preparing an asphalt cement composition comprising the step of:
- blending a propane-precipitated asphalt base, air-treated at elevated temperature and having a softening point of about 65.degree.-300.degree. C. as measured by ASTM D 36-76, with about 5-60 wt.%, based on the total weight of said asphalt base, of a 1-10 wt.% sulfur-treated liquid petroleum fraction having an atmospheric equivalent boiling range, of about 370.degree.-500.degree. C., thereby producing an asphalt cement composition being of ASTM viscosity grade AC-21/2, AC-5, AC-10, AC-20 or AC-40 and meeting the requirements of ASTM D 3381-76 or AASHTO M 226-73, and exhibiting a higher viscosity at 60.degree. C., as measured by the procedure of ASTM STP 532 (1973), in which said viscosity is interpolated at a penetration level of 90 decimillimeters at 25.degree. C., than a comparative non-air treated composition derived from the same propane-precipitated asphalt, whose softening point has not been increased.
A process for preparing an asphalt cement composition comprising the steps of:
- (a) contacting a molten propane-precipitated asphalt, derived from a residuum of a crude oil, having a gravity of above about 20.degree. API, with a stream of air at a temperature of above about 200.degree. C. resulting in an air-treated asphalt base having a higher softening point than said propane-precipitated asphalt and being in the temperature range of about 65.degree.-300.degree. C., as measured by ASTM D-36-76;
- and
- (b) blending said air-treated asphalt base, at a temperature of about 125.degree.-150.degree. C., with about 5-60 wt.%, based on the total weight of said asphalt base, of a 1-10 wt.% sulfur-treated liquid petroleum fraction having an atmospheric equivalent boiling range of about 370.degree.-500.degree. C., thereby producing an asphalt cement composition being of ASTM viscosity grade AC-21/2, AC-5, AC-10, AC-20 or AC-40 and meeting the requirements of ASTM D 3381-76 or AASHTO M 226-73, and exhibiting a higher viscosity at 60.degree. C., as measured by the procedure of ASTM STP 532 (1973), in which said viscosity is interpolated at a penetration level of 90 decimillimeters at 25.degree. C., than a comparative non-air treated composition derived from the same propane-precipitated asphalt, whose softening point has not been increased.
Dependencies are inferred from the claim text.