Plastics reactors themselves don't really do much (if tuned properly, most aren't because it's cheaper), the emissions are mostly from the refinery processes be

Plastics reactors themselves don't really do much (if tuned properly, most aren't because it's cheaper), the emissions are mostly from the refinery processes before it. You can't make plastics from raw oil. Obviously running these still requires a lot of power for heating, cooling and so on. Large-scale extruders for producing the plastic pellets everyone uses for e.g. injection moulding require a fair bit of electricity as well (think dozens of MW per screw pair / channel).