MAJOR TYPES OF COAL VARY IN THEIR CARBON AND ENERGY CONTENT
FIGURE 9.2 The energy content of coal increases from lignite to bituminous coal; anthracite has slightly lower energy content than bituminous coal.
(Courtesy Dan Mosier) (kkymek/Shutterstock) (Michał Baran´ ski/Getty Images) (Antoni Halim/Shutterstock)