Economic assessment of hydrogen and electricity cogeneration through steam reforming-SOFC system in the Brazilian biodiesel industry

Abstract

The increase of environmental concern has led to an increase in biodiesel production, which also produces high amounts of glycerol. This growing production is causing glycerol prices to plummet while constant efforts are being made in order to find suitable applications for this compound. In this sense, this work aims to evaluate the economic potential for hydrogen production by the steam reforming of glycerol in the Brazilian biodiesel industry to be used as fuel in a Solid Oxide Fuel Cell (SOFC) afterwards. Mathematical and computer models were developed to evaluate the potential heat and power generated by this configuration and the project was economically assessed. Even though glycerol could produce much more electricity through the proposed assembly than is actually needed, the economic aspect makes the project unsuitable for practical uses. Hydrogen production costs (2.42–5.26 USD/kg) were higher than those reported for traditional reforming methods and similar to other alternative pathways, but remained below the range commonly found in the market, indicating a potential for selling H2 directly. The use of SOFCs for electricity production, however, was found to make the system unsuitable, mostly due to its high investment costs, which represents from 41.8% to 65.1% of the total costs depending on the financing scenario. Even in the best economic scenarios, the costs for producing energy from such system remained above 0.269 USD/kWh, far higher than the 0.116 USD/kWh normally found in the Brazilian market.