Residues generated by the productive chain of porongo (<i>Lagenaria siceraria</i> (Molina) Standl.) as an alternative source of bioenergy

Abstract

The bottle gourd (Lagenaria siceraria (Molina) Standl.) is a fruit widely cultivated in southern Brazil for its use in the production of gourds, generating a large amount of waste obtained from the processing of the shell. In this context, the use of waste generated by the production chain of bottle gourds was evaluated as an alternative source of bioenergy through the production of briquettes. The chemical characterization of the residue was performed based on the contents of total extractives, lignin, carbohydrates and immediate chemistry (ash, volatile materials, and fixed carbon). Briquettes were produced through three different granulometric treatments for the processing of the material: in natura (Treatment 1), 10/20 mesh fraction (Treatment 2), and 20/40 mesh fraction (Treatment 3). The basic density and calorific value of the residue and the apparent, bulk, and energetic densities of the briquettes were also evaluated. The mechanical strength was determined based on the compression analysis of the briquettes. For the analyses of total extractives, lignin, carbohydrates, ash, fixed carbon, and volatile materials, values of 1.67%, 30.70%, 58.07%, 1.84%, 14.49%, and 83.67% were found, respectively. The basic density of the gourd shell was 0.24 g/cm³ and the calorific value was 3902.9 Kcal kg-1. The apparent densities were 1.03 g/cm³(1), 1.04 g/cm³(2), and 1.28 g/cm³(3) in bulk of 0.16 g/cm³ for the three treatments, and the energetic values were 4.07Mcal/m³(1), 4.09Mcal/m³(2) and 5.04Mcal/m³(3). For compressive strength, the briquettes resulted in values of 57.49MPa(1), 59.45MPa(2), and 74.36MPa(3). Through the treatments studied, the residue transformed into briquettes proved to be an alternative source of energy generation, with emphasis on Treatment 3. Based on the analyses performed, it was possible to conclude that residue from gourd shells presents desirable physical and chemical characteristics to be used as biomass for energy purposes.