• Energy Research

Abstract The constant concern with the environment and the depletion of fossil fuels has attracted interest in renewable energy from bio resources and/or materials wasted incorrectly. The process of anaerobic digestion converts organic waste into valuable energy sources, while reducing the pollution potential of this waste to the environment. The study was designed to analyze the biogas and methane generation potential from organic by-products of wine. Using the methodology described in VDI 4630 and automated biogas quantification based on the displacement of fluids. The results showed the biogas and methane production potential of the wine biomasses, and the ones with greatest potentials are grape must, the mixture of all biomass and bagasse 1.151; 289 and 199 m3 biogas.tonVS−1, respectively. Likewise, it was verified that biomass energy recovery for methane production has the capacity to supply approximately 2% of the natural gas demand in Rio Grande do Sul. These results presented specifically the biomass characterization of the wine sector and as potential energy for the production of biogas and methane, verifying the possibility of using this form of clean and sustainable energy on a large scale.

Abstract The use of industrial fish processing waste as the only substrate to produce biogas may be an efficient procedure due to its characteristic lipid content. The relationship between the microbial community and the biogas/methane production was evaluated during the anaerobic digestion at 35 °C of two waste types derived from the fish processing industry. The experiments showed that fish waste (FW) and fish crude oil waste (FCOW) produced methane at 540.5 CH4 mL gVS−1 and 426.3 CH4 mL gVS− 1, respectively. Clostridia, Synergistia were the predominant bacterial classes and the Methanomicrobia archeal class at the end of the anaerobic digestion in both substrates. The fungal community was similar in both treatments. The fungal diversity included orders of the Ascomycota phylum: Eurotiales, Sordariales, Saccharomycetales, Sporidiales, Capnodiales and Microascales. Representatives of Basidiomycota included Wallemiales and Tremellales. This research demonstrated that industrial fish processing waste can be efficiently converted to methane in a mono-digestion process.

AbstractThe anaerobic digestion of industrial wastes produces a biogas that is an alternative to the use of fossil fuels for energy production. At the end of this process, the stabilized biomass presents high levels of nutrients, which can be used both as biofertilizers in agriculture and for the biodegradation of contaminants in the soil through improvement of the microbiota. Thus, this study aimed to evaluate biogas production by industrial wastes and to use the biofertilizer for the bioremediation of soils previously contaminated with gasoline. The biomass (420 mL) generated approximately 10 liters (L) of methane and 3 L of other gases. Anaerobic incubation reduced total and volatile solids, as well as biochemical oxygen demand, chemical oxygen demand, and the carbon and nitrogen contents of the biomass. The bioremediation experiment showed that 15 days after contamination with gasoline, the addition of the biofertilizer improved the degradation efficiency of monoaromatic hydrocarbons; however, the degradation of polyaromatic hydrocarbons was less time efficient. So, we conclude that the anaerobic incubation of industrial wastes generates a high amount of biogas, and that biofertilizer deposition into contaminated soil does not affect the efficiency of the degradation of aromatic hydrocarbons after 30 days. Novelty or significance: Anaerobic incubation of industrial wastes generates a high calorific value gas, which can be used as an alternative source of energy. And, the resulting biomass, called biofertilizer, can be used to remediate soils contaminated with hydrocarbons.

Hulls are considered residues from rice production, and due to its low commercial value, there is little interest in developing biotechnological approaches for its reuse. However, the biological pre-treatment can be a safe and environmentally friendly alternative for developing new uses for this waste material. Therefore, this work aimed to select efficient fungal isolates to be used in the pre-treatment of rice hulls to enhance methane production in anaerobic digestion processes. Two fungal isolates (Pleu1 and Shi2) were able to grow in media containing rice hull as the sole carbon source. Further, ideal conditions for rice hull colonization were evaluated, and 28 °C and 60% humidity were used to inoculate this material. Rice hulls inoculated with Shi2 for 30 days presented approximately 27% and 10% reduction in lignin and cellulose/hemicellulose contents, respectively. Crushed rice hulls inoculated with Shi2 presented an increase of approximately 4.5-fold in biochemical methane potential when compared to non-inoculated material. This work reports the first step for new applicability of rice hulls. However, other studies are needed to show the economic viability and efficiency of this biological process aiming a large-scale application.

Abstract Currently, global demand for energy has grown and the search for new ecological energy sources is one of the mostly significant issues we face. The digestion of alternative sources of carbon in anoxic environment produces gas of high calorific value, which is a promising source of alternative energy. Thus, this work aimed to evaluate the biogas production of waste originated from a slaughterhouse industry of pigs and poultry, and from the dairy industry, and to characterize the physicochemical properties and microbiological composition of the biogas-producing biomass. Residues were collected and physicochemical and microbiological parameters were evaluated in four different stages of biogas production. At the end of 42 days, approximately 26 L of methane and 12 L of other gases were produced. The high amount of biogas/methane observed was related to the families Porphyromonadaceae, Tissierellaceae, and Methanobacteriaceae. Although less than 6% of the total reads lack classification at any taxonomic level, our analysis showed that about 50% of the sequences did not present a homologue sequence at the genus level in public databases. Knowledge about changes in the microbial composition and their dominance can provide tools for manipulation, isolation, and inoculation of the microorganisms inside the bioreactors to maximize methane production.