Produção biológica de hidrogênio a partir da manipueira em reator anaeróbio de leito fluidificado: Efeito da adição de esgoto sanitário para redução da carga orgânica

Abstract

This study aimed to assess the biological production of hydrogen from association between cassava and sewage in two fluidized bed reactors (AFBR 1 and 2). Thus, it was used as support material crushed expanded clay (2.8 to 3.35 mm diameter). Two reactors of different sizes were used (RALF 1 190 cm height and 5.3 cm internal diameter and RALF 2 90 cm and internal diameter of 4 cm ), and both of them with added glucose (RALF 1 with concentrations of 3 , 2 , 1 g.L-1 and RALF 2 with 10, 5, 2 g.L-1, respectively, the first three phases in both reactors). The reactors were inoculated with swine waste pre heat treated and operated with a hydraulic retention time of 4-3h (RALF 1) and 4h (RALF 2) at room temperature. The pH of the effluent ranged from 4.47 and 5.52 in RALF 1 and between 3.87 and 4.63 in RALF 2 . The conversion rate of glucose conversion was 85.44% and 71% in RALFS 1 and 2, respectively. Was found maximum volumetric hydrogen production of 3.09 L.h-1.L-1 in RALF 1, when the HRT was reduced from 4 to 3 hours, with no addition of glucose and the percentage of sewage was replaced by water. The maximum yield of hydrogen in RALF 1 (1.11 mol H2. mol glucose - 1) was detected in F50M1G phase. In RALF 2, there was no volumetric hydrogen production detected by the meter, with theoretically calculated and obtained the maximum value of 0.98 L.h-1.L-1 in F50M2G phase. The highest yield of hydrogen was obtained in RALF 2 with 2.03 mol H2. mol glucose -1 in F100M phase. The soluble metabolites were measured acetic, butyric, propionic and ethanol to their respective maximum percentage of 42, 15, 25 and 98 % to RALF 1 and 50, 13, 31 and 97 % in RALF 2. The results indicated that the predominant route of hydrogen evolution was ethanol. The production of gases, organic acids and alcohols in the reactors were maintained throughout the 127 days of the experiment.