High School Earth, Space, and Geophysical Curriculum Essentials May 2009 9. Boulder Valley School District High School Earth, Space, and Geophysical. Science Curriculum Essentials Document. Enduring Understandings. are the big ideas central to a content area that have lasting value beyond the classroom and.
See also: Coal gasification and Coal seam gas. Coal gas is a flammable gaseous fuel made from coal and supplied to the user via a piped distribution system. Town gas is a more general term referring to manufactured gaseous fuels produced for sale to consumers and municipalities.
Coal is a chemically complex fuel. Whenever it is burned, gases are given off and particles of ash, called fly ash, are released. The sulfur in coal combines with oxygen to form sulfur dioxide, which can be a major source of air pollution if emitted in large enough quantities.