Influência do inóculo na produção de hidrogênio a partir do soro de queijo em pó, da lactose isolada e do efluente da indústria de laticínios em reator anaeróbio de leito fluidificado

Abstract

The great energy potential and no pollutant gas emissions are hydrogen characteristics (H2) that enable its use as fuel. In addition to these advantages, the hydrogen gas can also be obtained from anaerobic processes using organic compounds, such as wastewater from agribusiness. The dairy industries are placed in this framework of possibilities, considering that during the product manufacturing processes, it generates a large volume of wastewater with a high concentration of organic matter and carbohydrates (lactose), making these attractive effluents to produce H2. However, most studies realized until now have used the cheese whey or isolated lactose as a substrate. In this work, the production of H2 from the actual effluent was collected in the dairy industry, in addition to whey powder and isolated lactose, to analyze the viability of using the sheep rumen and natural fermentation as inoculants to these three different substrates. For this, we used two anaerobic fluidized bed reactors. The first reactor (R1) was inoculated with rumen, and the second reactor (R2) was performed auto fermentation of the dairy effluent. Both with the same configuration and operated continuously. The hydraulic retention time varied between 6h and 4h until the stabilization phase, which was kept at 2h. The results showed that the presence of the rumen has a great influence in the production of H2. About the metabolites products in the process, acetic acid and ethanol were those most present during operation of both reactors. The maximum yield was 1.66mol.H2/mol.carbohydrate and occurred in R1 when cheese whey was used as substrate. The reactor, which used the natural fermentation procedure, was more viable than the reactor with inoculum, only when the substrate was the dairy effluent.