What is coal and how is it formed? What are the major advantages and disadvantages of using coal as an energy resource? Explain why there is no such thing as clean coal. What is synthetic natural gas...

What is coal and how is it formed? What are the major advantages and disadvantages of using coal as an energy resource? Explain why there is no such thing as clean coal. What is synthetic natural gas (SNG)? What are the major advantages and disadvantages of using liquid and gaseous synfuels produced from coal?