Chapter 1
solids. The splitter underflow tails and polisher sludge are mixed with additional
naphtha to raise naphtha/ bitumen (N/В) ratio to 4.0 -10.0. This mixture enters
scrubber. Scrubber overflow containing residual bitumen and polisher sludge are
recycled to splitter. Polished diluted bitumen is sent for solvent recovery and
finally transported to refinery.
During this continuous process, a rag layer contains oil, water and solid forms
in the middle of scrubber, which prevents complete separation. The accumulation