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.
The Geology of Pennsylvania consists of six distinct physiographic provinces, three of which are subdivided into different sections. rock with high economic value from Pennsylvania is Anthracite coal. Before mining began, there was an estimated 22.8 billion tons of anthracite in Pennsylvania. In 2001, 12 billion tons still remained in the ground, most of which was not economically feasible to mine.