LONDON, December 1, 2015 /PRNewswire/ — ICIS, a global leader for petrochemicals market intelligence, has released the 2015 version of the World Petrochemical Feedstocks Survey for Olefins. North American developments and global feedstock diversification are transforming the petrochemical feedstock landscape. Whilst forecasts for ethylene demand growth are positive, changing trade flows and evolving technology will shift…