Ethane vs. Naphtha to produce ethylene: How does it work for RIL?

What is the big advantage that RIL plans to have by moving from naphtha to ethane to fire its petrochemical plants
8The RIL model is based on the advantages that the US petrochemical industry is reaping from low cost of cost
8The driver of U.S. competitiveness is the cost to convert ethane to ethylene versus naptha to ethylene...http://goo.gl/WNluOb