A buildout in new petrochemical capacity in China is fueling fears that the country could tip the global market into oversupply, hurting smaller petrochemical producers. Bloomberg reported today that China’s polyethylene production could add 18% this year, based on forecasts by a local consultancy. The output growth will significantly exceed expected growth in demand, at 10%, and lead to a 13% decline in polyethylene imports. China is already the world’s biggest producer of ethylene and polyethylene, after building seven petrochemical…