Method for heat recovery from pre-treated biomass

According to one embodiment, a method for heat treatment of a biomass includes allowing biomass in a pretreatment reactor to undergo a pre-treatment reaction process. The pre-treatment reaction process yields pretreated biomass along with soluble components. A first liquid having a first temperature is transported into the pretreatment reactor and the pretreated biomass elevates the first temperature to a second temperature. At least a portion of the soluble components are captured in the first liquid, and the at least a portion of the soluble components in the first liquid and the first liquid are removed from the pretreatment reactor. A second liquid having a third temperature is transported into the pretreatment reactor and the pretreated biomass elevates the third temperature to a fourth temperature, the fourth temperature being less than second temperature.U