Propane is bought and stored in a liquid form (LPG), and thus fuel energy can be stored in a relatively small space. Compressed natural gas (CNG), largely methane, is another gas used as fuel, but it cannot be liquefied by compression at normal temperatures, as these are well above its critical temperature.
Anthracite accounts for about 1% of global coal reserves, and is mined in only a few countries around the world. China accounts for the majority of global production; other producers are Russia, Ukraine, North Korea, South Africa, Vietnam, the UK, Australia and the US.he term is applied to those varieties of coal which do not give off tarry or other hydrocarbon vapours when heated below their point of ignition. Anthracite ignites with difficulty and burns with a short, blue, and smokeless flame.
12,000 to 14,000 Btu/lb for anthracite coal. 1.2.2 Firing Practices6-8 Due to its low volatile matter content and non-clinkering characteristics, anthracite coal is primarily used in medium-sized industrial and institutional stoker boilers equipped with stationary or traveling grates. Anthracite coal is not used in spreader stokers because of its low volatile matter content and relatively high ignition temperature.