Another aspect that interested Straser is how cheaply the Laurus process can gasify the coal underground. Straser says the company hadn’t pursued any surface gasification processes, which could be on the order of, say, $2 billion, but that Laurus can do the equivalent in the coal seam for one twentieth of that price. He adds that since the underground gasification process leaves char and other “really nasty stuff” in the ground, it’s a cleaner process than extracting coal and gasifying it above ground