The strong drawing of the modern boilers generally drags a certain amount of bagasse not burned in the combustion gases. This bagasse, not burned, known as soot, pollutes the industrial unit and its neighborhoods. Because of that, a retainer of soot was developed through humid process that controls this potential problem in satisfactory way.

The water for washing of the gases that enters in the retainer under pressure is atomized in the sprinklers. These nipples are distributed along the internal rings and between the rings there is a baffle of gases, which has the purpose of increasing the contact gas-water. The entrance of the gas is given tangentially in the inferior part of the retainer, making the gas to circulate in contact with the water. The atomized water particles in the nipples capture the soot, ashes and sand from the gases, dragging them to the bottom of the retainer. From it, this water flows off due to gravity, through pipes or canals, until the decanter of soot. From the decanter, the treated water is pumped again to the retainer, closing the circuit.

Moreover, Group Farias obtains an energy exploration of the bagasse in the productive process. With this, it prevents emission of gases that contributes for the Greenhouse Effect in a corresponding volume of 5% of the originated from the emission of fossil fuel burning in Brazil. Actions such as this qualify the country to receive credits under the conditions of the Clean Development Mechanism of the Kyoto Protocol.