Rice husk energy production in Brazil: An economic and energy extensive analysis

Abstract Brazil is one of the most prominent rice producing nations in the world, with an annual output of more than 11 million tons. Rice husk is one of the main byproducts in rice processing. Large volumes of this residue are generated when processing the grains. This byproduct has great calorific value, and thus possesses significant potential for electrical energy generation. This study presents a thorough economic and energy analysis of rice husk energy production on a regional and national scale in Brazil. Furthermore, economic viability analysis was assessed through a variety of scenarios. Data were collected from rice cultivation areas throughout the country, including every Brazilian city where rice is grown, in order to identify the minimum planting area to enable power generation from rice husks. Then, economically viable energy potential was calculated. The minimum area for rice cultivation in order to guarantee economic viability varied from 700 to 26,700 ha, depending on the economic scenario. Levelized costs of electricity and net present values varied from 53.71 to 164.94 USD/MWh, with an average of 112.2 USD/MWh, and −1 to 7.3 106 USD, being highly influenced by the planting area. In more optimistic scenarios, the viable energy potential of this biomass in Brazil can exceed 2.5 TWh/year, which represents around 5% of the country’s total bioenergy production. Such results demonstrate that energy generation from rice husks can be an important resource to increase bioenergy generation in Brazil. This tendency was particularly pronounced in the South, where rice production is more concentrated.