Lancan gas is a medium to low temperature dry distillation process of coal in an upright furnace at 600 ℃. The recovered coal gas is then ignited and dried to form semi coke, also known as Lancan. The tail gas of this Lancan furnace is called Lancan gas or Lancan tail gas. The direct discharge or venting combustion of blue charcoal exhaust gas exceeds the standard and pollutes the environment. The low-temperature dry distillation orchid charcoal kiln produces about 600-700 cubic meters of orchid charcoal gas per ton of orchid charcoal produced, with a calorific value of around 7950 KJ (1900 kcal), which can meet the demand for power generation.

Charcoal gas calorific value: The calorific value is 6732-8439kJ/m3 (1609-2017 kcal) per standard cubic meter, belonging to low calorific value gas.

Composition of Blue Charcoal Gas: Its main components are methane (8.8% -17.6%), hydrogen (12% -28%), carbon monoxide (6% -22%), unsaturated hydrocarbons (0.8% -1.2%), nitrogen (44% -52%), oxygen (0.2% -5%), carbon dioxide (2% -12%), and hydrogen sulfide (0.4% -0.8%)

Analysis of the composition of by-product gas from the current internal heating orchid charcoal furnace, with a calorific value of around 7950KJ (1900 kcal)