Kinetic study of anaerobic bio digestion of vinasse and pentoses liquor arising from production of ethanol from sugarcane

Abstract

The projection of the sustainability in the sector of bioethanol production from sugar cane in the Brazil motivated the development of searches for the energetic optimization of the process together with the compatibility environmental of waste generated. In this scenario the anaerobic digestion of liquid effluents from production is an interesting alternative since in addition to promoting the stabilization of organic matter present in the effluent enables power generation from biogas generated. This approach also stimulates the production of 2nd generation ethanol i.e., the ethanol produced from lignocellulosic material from bagasse of sugar cane. The cogeneration of energy from the burning of bagasse could be replaced by biogas, particularly methane from anaerobic digestion of this material. Unlike the production of first generation ethanol (from sugar cane juice) the 2nd generation ethanol is still quite recent and limited, but it is known that the effluent from the pre-treatment of the bagasse, the pentose liquor must be properly handled so that environmental damage be avoided. Other waste of high-polluting power is the vinasse that is generated in large volumes during the distillation of ethanol. Although there are some researches about anaerobic digestion of vinasse from sugar cane the lack of information regarding fundamental aspects of this process prevents the full implementation and optimized this technology in power plants. The obstacles are even greater in relation to pentose liqueur due to absence of information available in the literature about the anaerobic digestion of this material except the attempts of its use for the production of ethanol or other products on a biorefinery. Thus, this research aims to characterize the kinetics of anaerobic digestion of vinasse and pentose liqueur with a view to contribute to the implementation and expansion of this sustainable technology.