LNG COOPERATION -- ExxonMobil vice president of gas and power marketing Richard Guerrant (left) and the president and Korea Gas Corp. chief executive Lee Seung-hoon pose after signing a memorandum of understanding to jointly pursue new opportunities in the natural gas value chain at a ceremony held in Seoul on Wednesday. LNG -- a cleaner burner fuel compared to other non-renewable energy sources -- is expected to replace coal as the No. 2 global source of energy, a shift that reflects the versatility, efficiency and availability of natural gas. (ExxonMobil Korea)