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- Ultrasound as pretreatment in biogas production from crude glycerolPublication . Zschacl, Lis; Kreutz, Cristiane; Martins, RamiroAir pollution, acid precipitation, ozone depletion and the gaseous emissions to the atmosphere are associated to the petroleum derivate use, currently considered the main energy source used in the world. Renewable energy sources are expected to replace them in order to solve these environmental concerns. Biofuels as biodiesel and biogas are renewable energy produced from natural matter. Studies made suggest that using the principal by-product of biodiesel’s production process, crude glycerol, is possible to obtain biogas. Biogas can be produced from an anaerobic digestion process and enhanced by using pretreatment in substrate. This work tested ultrasound pretreatment on crude glycerol as a substrate in the biogas production. Different times of pretreatment (15 and 30 minutes) were examined, to determinate the best performance and compare it to the untreated substrate. The biogas production was daily measured directly from the reactors. The results showed that ultrasound pretreatment improved methane production. The best result was obtained by using 30 minutes of pretreatment on crude glycerol.
- Effect of ultrasound in crude glicerol as pretreatment for methane productionPublication . Zschach, Lis Geraldine; Giacon, Mariana Ferrari; Afonso, Maria João A.P.S.; Kreutz, Cristiane; Martins, RamiroAs global energy supply is based on petroleum derivate, scarcity of natural sources and environmental concerns are problems associated to the energy supply as well as the increasing demand. Renewable energy sources can replace this conventional energy source and decrease the environmental emissions.. In this work is going to be evaluated the effect of ultrasound pretreatment on crude glycerol from biodiesel production process to improve the methane production from biogas in an anaerobic digestion process. Different times of pretreatment are going to be examined 10, 15 and 30 minutes to determinate the best performance and compare it to the untreated substrate. The results showed that ultrasound pretreatment improved methane production by using 30 minutes of treatment on crude glycerol.
- Biogas production by anaerobic codigestion using kiwi waste and wine sludgePublication . Giacon, Mariana Ferrari; Zschaach, L.G.; Afonso, Maria João A.P.S.; Kreutz, Cristiane; Martins, RamiroConsidering a large generation of wastes, the anaerobic codigestion (AcoD) is an alternative to transform two or more types of organic waste in energy and biofertilizer. To test the biogas production potential using kiwi waste and wine sludge, two AD assays with each substrate isolated and AcoD with four different substrate proportion was realized, using as inoculum sludge from a septic tank. The experimental was realized during 19 days in batch reactor (250 mL). Among digestion results, kiwi waste had de best result, being 27.0 mLN gVS-1 of biogas. The most satisfactory value in AcoD was 40.5 mLN g VS-1 of biogas, from treatment with 0.5 g kiwi and 3.3 g wine sludge. The AcoD test produced 16 mLN gVS-1 of biogas more than AD
- Anaerobic digestion performance in the energy recovery of kiwi residuesPublication . Paulista, Larissa Oliveira; Boaventura, Rui; Martins, RamiroWorld production and trade of fruits generate losses in the harvest, post-harvest, handling, distribution and consumption phases, corresponding to 6.8% of total production. These residues present high potential as a substrate for the anaerobic digestion process and biogas generation. Thus, the energy valuation of the agro-industrial residues of kiwifruit production was evaluated by anaerobic digestion, aiming at optimizing the biogas production and its quality. Ten assays were carried out in a batch reactor (500 mL) under mesophilic conditions and varying a number of operational factors: different substrate/inoculum ratios; four distinct values for C: N ratio; inoculum from different digesters; and inoculum collected at different times of the year. The following parameters were used to control and monitor the process: pH, alkalinity, volatile fatty acids (VFA), volatile solids (VS) and chemical oxygen demand (COD). Among the tests performed, the best result obtained for the biogas production corresponded to the use of 2 g of substrate and 98 mL of inoculum of the anaerobic digester of the Wastewater Treatment Plant (WWTP) of Bragança, with addition of 150 mg of bicarbonate leading to a production of 1628 L biogas.kg-1 VS (57% methane). In relation to the biogas quality, the best result was obtained with 20 g of substrate and 380 mL of inoculum from the anaerobic digester sludge of Ave WWTP (plus 600 mg of sodium bicarbonate), presenting a value of 85% of CH4, with a production of 464 L biogas.kg-1 VS.
- Anaerobic digestion performance in the energy recovery of kiwi residuesPublication . Martins, Ramiro; Boaventura, Rui; Paulista, Larissa OliveiraWorld production and trade of fruits generate losses in the harvest, post-harvest, handling, distribution and consumption phases, corresponding to 6.8% of total production. These residues present high potential as a substrate for the anaerobic digestion process and biogas generation. Thus, the energy valuation of the agro-industrial residues of kiwi production was evaluated by anaerobic digestion, aiming at optimizing the biogas production and its quality. Ten assays were carried out in a batch reactor (500 mL) under mesophilic conditions and varying a number of operational factors: different substrate/inoculum ratios; four distinct values for C: N ratio; inoculum from different digesters; and inoculum collected at different times of the year. The following parameters were used to control and monitor the process: pH, alkalinity, volatile fatty acids (VFA), volatile solids (VS) and chemical oxygen demand (COD). Among the tests performed, the best result obtained for the biogas production corresponded to the use of 2 g of substrate and 98 mL of inoculum of the anaerobic digester of the Wastewater Treatment Plant (WWTP) of Bragança, with addition of 150 mg of bicarbonate leading to a production of 1628 L biogas.kg-1 VS (57% methane). In relation to the biogas quality, the best result was obtained with 20 g of substrate and 380 mL of inoculum from the anaerobic digester sludge of WWTP of Ave (with addition 600 mg of sodium bicarbonate), presenting a value of 85% of CH4, with a production of 464 L biogas.kg-1 VS.
- Ultrasound as pretreatment in biogas production from crude glycerolPublication . Zschach, Lis Geraldine; Kreutz, Cristiane; Martins, RamiroThe global energy supply is based on petroleum derivate. Air pollution, acid precipitation, ozone depletion, deforestation and the gaseous emissions to the atmosphere are associated to the petroleum derivate use. Renewable energy sources are expected to replace them in order to solve these environmental concerns. Biofuels as biodiesel and biogas are renewable energy produced from natural matter. Studies made suggest that using the principal by-product of biodiesel’s production process, crude glycerol, is possible to obtain biogas. Biogas can be produced from an anaerobic digestion process and enhanced by using pretreatment in substrate. This work tested ultrasound pretreatment on crude glycerol as a substrate in the biogas production. Different times of pretreatment (15 and 30 minutes) were examined, to determinate the best performance and compare it to the untreated substrate. The biogas production was daily measured directly from the reactors. The results showed that ultrasound pretreatment improved methane production. The best result was obtained by using 30 minutes of pretreatment on crude glycerol.
- Ultrasound as pretreatment in biogas production from crude glycerolPublication . Zschach, Lis Geraldine; Kreutz, Cristiane; Martins, RamiroAir pollution, acid precipitation, ozone depletion and the gaseous emissions to the atmosphere are associated to the petroleum derivate use, currently considered the main energy source used in the world. Renewable energy sources are expected to replace them in order to solve these environmental concerns. Biofuels as biodiesel and biogas are renewable energy produced from natural matter. Studies made suggest that using the principal by-product of biodiesel’s production process, crude glycerol, is possible to obtain biogas. Biogas can be produced from an anaerobic digestion process and enhanced by using pretreatment in substrate. This work tested ultrasound pretreatment on crude glycerol as a substrate in the biogas production. Different times of pretreatment (15 and 30 minutes) were examined, to determinate the best performance and compare it to the untreated substrate. The biogas production was daily measured directly from the reactors. The results showed that ultrasound pretreatment improved methane production. The best result was obtained by using 30 minutes of pretreatment on crude glycerol.
- Treatment and energy valorisation of an agro-industrial effluent in upflow anaerobic sludge reactor (UASB)Publication . Martins, Ramiro; Boaventura, Rui; Paulista, Larissa OliveiraThe accelerated growth of the population brings with it an increase in the generation of agro-industrial effluents. The inadequate discharge of these effluents significantly affects the quality of water resources. In this way, it becomes important to invest in treatment processes for agro-industrial effluents, particularly low-cost ones. In this context, the present study includes the design and construction of an UASB reactor and optimization of the anaerobic digestion treatment of the raw effluent from sweet chestnut production in the agro-industrial company Sortegel. The efficiency of the system was evaluated through the determination / monitoring of oxygen chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total suspended solids (TSS), biogas production rate and quality (% methane). The reactor was fed for 25 weeks and operated under mesophilic conditions (temperature 30-40 °C). Different values were tested for the hydraulic retention time (HRT) and volumetric flow rate (VF): 0.66 days (VF=1509 L.m-3.d-1); 1.33 days (VF=755 L.m-3.d-1); 2.41 d days (VF=415 L.m-3.d-1). The average COD removal efficiency reached values of 69%, 82% and 75%, respectively, and simultaneously the associated BOD5 removal efficiency was 84%, 91% and 70%. As regards TSS, removal values were 78%, 94% and 63%. In addition, high methane production rates were obtained, between 2500 and 4800 L CH4.kg-1 COD removed d-1. For all the hydraulic retention times tested, high concentrations of methane in the biogas were recorded: 66-75%, 70% and 75% for HRT of 0.66, 1.33 and 2.41 days, respectively.
- Anaerobic digestion in the fruit waste disposal and valorizationPublication . Baumguertner, Matheus Maranho; Kreutz, Cristiane; Martins, RamiroIt is estimated that around 25% of kiwi fruit production is disposed of as waste. This problem has created an opportunity to evaluated the potential for biogas generation using kiwi waste as a substrate by the anaerobic process, a complex biologic treatment performed in the absence of oxygen, used to stabilize organic matter while producing biogas. Eight distinct assay were performed, were carried out in two batch reactors (R1 and R18). Different substrate/inocu-lum ratios, addition of NaHCO3 and with and without nutrients addition being tested. The most satisfactory results were obtained with: kiwi waste (8.4 g), anaerobic digester slurry (192 mL), sodium bicarbonate (500.4 mg), ammonium chloride (453.0 mg) and potassium phosphate mon-obasic (106.0 mg) added. In this assay, 759.1 mL biogas / g VS was produced and methane quality of 60%.