De-asphalting – Application Overview

De-Asphalting – Application Overview

A de-asphalter separates asphalt from crude oil or bitumen using propane (or hexane) as a solvent.

The de-asphalter unit is usually placed after the vacuum distillation tower. A de-asphalter unit (SDA) separates asphalt from the feedstock based on differences in solubility. The products are then evaporated and steam stripped to recover the propane, which is recycled. De-asphalting also removes some sulphur and nitrogen compounds, metals, carbon residues and paraffins from the feedstock.

The output from the de-asphalter unit is de-asphalted oil (“DAO”) and asphalt.

FLOW DIAGRAM
Item	Applications	Temp range (°F)	Pressure (psi)	Size (in)
1	Feed isolation	200 – 500	400 – 900	4 – 16
2	Solvent circulating pump isolation	200 – 500	400 – 900	4 – 16
3	Asphaltene separator emergency block valve	200 – 500	400 – 900	4 – 16
4	Asphaltene separator isolation	200 – 500	400 – 900	4 – 16
5	Solvent surge drum emergency block valve	200 – 500	400 – 900	4 – 16
6	De-asphalted oil separator emergency block valve	200 – 500	400 – 900	4 – 16
7	Asphalting stripper isolation	200 – 500	400 – 900	4 – 16
8	De-asphalted oil stripper isolation	200 – 500	400 – 900	4 – 16