Pygas processing: 

Pyrolysis gasoline (pygas) processing can be problematic due to the reactive nature of the stream. Undesirable reactor performance can result from fouling-induced pressure drop increase or activity loss, leading to the risk of shortened cycles and off-specification product.

Furthermore, the trend towards plastic circularity will heighten the challenge. More and more facilities are looking at processing plastic-waste-derived pyrolysis oil in their steam crackers, however this contains elevated and varying levels of contaminants. Some of these, including silicon, which acts as a permanent poison in the second-stage pygas reactor, are likely to pass through to the pygas unit, though the extent of this depends on the upgrading technology employed upstream of the cracker.