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 fossil fuel that is burned as an energy source, which results in emissions such as carbon dioxide, nitrogen, and sulfur. Coal use is associated with waste products both from the mining process to acquire the coal and also from the actual use of coal itself. Hydroelectric energy does not involve waste, but does pose potential problems to waterways.