ExxonMobil reported $15.4 billion in third-quarter profit Friday, more than double its earnings a year earlier, with its Gulf Coast refineries running at full capacity and diesel prices doing the rest. The company earned $3.72 per share, or $4.23 on an adjusted basis, beating Wall Street's $4.08 estimate. Adjusted net income reached $17.5 billion, making it one of Exxon's most profitable quarters ever. Exxon's energy products business earned $9.05 billion in adjusted profit, up from $4.1 billion in the second quarter. Its U.S. Gulf Coast refinery…