An ecosystem operated in a plant having a drying unit is provided. The ecosystem includes: a regenerative thermal oxidization unit for processing a waste gas to produce a hot gas; a first hot gas pipeline connected to the regenerative thermal oxidization unit and the drying unit, wherein the hot gas is transferred from the regenerative thermal oxidization unit to the drying unit via the first hot gas pipeline; a heat recovery unit disposed at the first hot gas pipeline to absorb heat from the first hot gas pipeline; an absorption refrigeration unit connected to a target to be cooled; and a hot liquid pipeline connected to the heat recovery unit and the absorption refrigeration unit, wherein the heat recovery unit transfers heat from the first hot gas pipeline to the absorption refrigeration unit via the hot liquid pipeline to actuate the absorption refrigeration unit to cool the target.