The benefits of using post-use plastic pyrolysis oil instead of naphtha and fossil fuel gases in steam cracking operations with respect to greenhouse gas emissions are detailed in a study that was funded by the American Chemistry Council and published in The Journal of Cleaner Production.
The study takes into account two different categories of facilities: "Nth" facilities, which have a capacity of more than 50,000 tons annually, and pioneer facilities, which have a capacity of less than 50,000 tons annually. The scaling factor is noteworthy; whilst GHG emissions from Nth facilities are lower than those from conventional operations, GHG emissions from pioneer facilities grow due to the usage of pyrolysis oil.
The research also takes into account two substitution ratios: 20% and 5%. It is not required to hydrotreat in order to remove chlorides and other pollutants when using merely 5% pyrolysis oil in place of naphtha and gases. The use of hydrotreated pyrolysis oil results in a large increase in greenhouse gas emissions. Hydrotreatment is required to safeguard equipment at a substitution ratio of 20%, which reduces the GHG benefit per kilogram.