Another modest rise was seen in US ethylene margins week on week, on the back of stronger spot prices and stable-to-weaker feedstocks, as per Platts. Ethane-based ethylene margins were estimated at 17.79 cents/lb, a rise of 2.20 cents/lb week on week. Margins using ethane/propane mix as feedstock were around 18.83 cents/lb, up from 15.64 cents/lb on Dec. 16. The best margins of ethane and E/P mix make them the preferred feedstocks of US olefins producers. US spot ethylene gained 2.50 cents/lb week on week, assessed Friday at 53-53.50 cents/lb on a 3- to 30-day basis that accounted for a contango structure. Market sources said supply is in the process of tightening ahead of major turnarounds in the US Gulf Coast in Q1 and Q2 of 2012. Margins using propane as feedstock improved from 2.87 to 5.05 cents/lb. Heavier feedstocks, including light naphtha, remained mostly in negative territory.
Cracker margin estimates use the current spot price and yields of the various cracker products from cracking various light and heavy feedstocks.