The reason this works and is much cleaner is you're not burning coal. You're instead gasifying coal," Williams said."And, therefore, things don't go up into the atmosphere?" Stahl asked."Well, when you gasify coal, you can take the pollutants out," Williams explained."You're saying before the coal is ever burned in any way, you can separate out the bad stuff?" Stahl asked."You do that very early on," Williams replied.