C4 3 : C4 derivates are among the main olefin products coming from the steam cracker, along with ethylene and propylene. Butadiene is the most valuable product from the C4 fraction
The Association of Petrochemicals Producers in Europe (APPE), The European petrochemical industry, Glossary of Terms on Chemical Safety for Use in IPCS Publications, van Nieuwenhuyse, Brussels 2006. http://www.petrochemistry.eu/glossary.html, (Petrochem Ind - Brit) {473}