Energy potential of biomass from two types of genetically improved rice husks in Brazil: A theoretical-experimental study

Abstract

This work aimed to characterize and evaluate the energy potential of the residual biomass of genetically improved rice varieties (Pampeira rice and Catiana rice) introduced in the Brazilian market in 2016 and an indefinite variety of rice to establish a comparison. The two varieties of rice species enabled an increase in producers' profits of up to 57% and therefore with high production of residues and without problems of supply. The thermogravimetric analysis (TGA), middle and near infrared spectroscopy were used to characterize the biomass. The TGA curves evidenced the degradation of lignocellulosic matter as hemicellulose and cellulose (120 °C and 350 °C) and lignin (350 °C and 600 °C). The middle and near infrared spectroscopy identified the main characteristic bands of the rice husks: O−H, Si−OH, −CH2, −CH3, C=O and C−O. The elementary analysis showed that the percentage of carbon 40.68% and 42.29% and the total lignin 33.21% and 31.55% for Catiana and Pampeira rice husk, respectively, have a good potential for generating useful energy. The higher heating values (HHV) 4409.50 kcal kg−1 and 4488.00 kcal kg−1 for Catiana and Pampeira risk husk evaluate and proven the energetic potential of these materials. On the other hand, the ash content determined is lower, which facilitates its application in the combustion process. The theoretical results showed that the lignin presents greater enthalpy of combustion, when compared with hemicellulose and cellulose, confirming the results of the experiments found in the work.