(25d) Improving Vacuum Tower Asphalt Quality

Andrew W. Sloley

The Distillation Group, Inc.

Bellingham, WA, USA

Asphalt is one of the lower value products from a refinery. However, a market exists for road paving, roofing, and other asphalt types. For refineries that lack bottoms conversion capability being able to meet asphalt specifications may be critical to overall refinery economics. This case study looks at a refiner with limited residual conversion capacity. Vacuum residue rom the crude vacuum unit goes to the asphalt and road oils market.

During their typical three-year run, production of road asphalts becomes more difficult during each successive summer. Finally, production of specific asphalt grades requires reduced crude rates. The reduction in crude runs directly reduced profits by limiting gasoline production during peak demand months. The objective of the work was to allow on-specification asphalt production at full crude rates during the summer.