New electrochemical devices for the production of high value products in the sugarcane sector: the production of H2 and conversion of CO2

Abstract

The vinasse is an agroindustrial wastewater that may represent an economical alternative with low carbon footprint to the commercial fertilizers. However, when it is direct applied to planting (in natura), the vinasse can cause several environmental and economical issues associated to water and soil degradation, emission of greenhouse gases and transport logistic difficulties. Currently, the concentration of vinasse is the most proper way to transpose this problems, usually by thermal processes that are rarely actually implemented. In this context, we propose the investigation of electrochemical technologies for the concentration of vinasse by selective water electrolysis (which is 93% of this effluent composition). As a result, it can be obtained the concentrated vinasse (for fertilizers application) and high added value products: the hydrogen and oxygen gases. These, as in turn, can be commercialized ou reused in the sugarcane and ethanol industry. For instance, the produced O2 can be applied to the oxy-combustion of sugarcane bagasse, resulting in clean energy for the electrolytic concentrator and high purity CO2 (that may be converted into industrial chemicals such as formic and oxalic acids, decreasing the CO2 emissions of the industry). This proposal involves several research fronts through an experimental/ multi-scale modeling approach. That is, it is expected the development of the electrochemical systems from catalyzers and electrodes to the design of the electrolyzers and their scale-up properties through several feedback cycles. This project specifically addresses the development of the electrochemical reactors for the vinasse concentration and for CO2 conversion into oxalic acid, as well as, their application to assess their efficiencies. Our proposal is to upgrade the sugarcane and agricultural industries to the reduction of greenhouse gases emissions also producing new commodities in this strategic national market. (AU)