Digestion Of Vinasse Research Articles

Biodigestão anaeróbia da vinhaça: aproveitamento energético do biogás e obtenção de créditos de carbono – estudo de caso

The increase of the ethanol production in Brazil leads to growing of vinasse (main by-product of sugar and alcohol industry), worsing the problem related to its destinantion. Vinasse is rich in nutrients and has a high content of organic matter, which justifies its intense ferti-irrigation use in sugar cane crop areas. Thus, the anaerobic digestion of vinasse by UASB (upflow anaerobic sludge blanket digestion) reactor emerges as an alternative treatment for this by-product, showing also an economic factor, the production of methane and its use. This work aimed to implement the system of anaerobic digestion of vinasse in UASB reactor and the use of energy generated by biogas. In this way, the design of UASB was based on organic volumetrical load of vinasse. The estimation of the baseline was based on the mass balance between the carbon present in the vinasse and CO2 emitted by the aerobic degradation of effluent into the environment. From the compute emissions, it was found that emissions from the baseline and the project implementation would be the same, and additionally it could be occur the production of electricity by biogas. In this way, biogas produced by anaerobic digestion has a competitive energy potential compared to other energy sources and presents additionality; however, carbon credits marked could not be a financial attractive in the development of this type of project.

Kinetic study of the anaerobic digestion of vinasse pretreated with ozone, ozone plus ultraviolet light, and ozone plus ultraviolet light in the presence of titanium dioxide

A comparative kinetic study of the anaerobic digestion of vinasse and vinasse following a 2 h treatment with ozone, ozone plus UV light or ozone plus UV light in the presence of titanium dioxide was carried out. All pretreatments decreased both chemical oxygen demand (COD) and total organic content (TOC). Those using no catalyst failed to improve the specific rate of methane production during anaerobic digestion but succeeded in increasing the yield coefficient ( Y P/ S , in ml CH 4/mg TOC). Finally, the pretreatment using ozone, UV light and titanium dioxide decreased COD and TOC, and increased the yield coefficient and also the mean specific rate of anaerobic digestion (by 25%) relative to untreated vinasse.

Thermophilic Anaerobic Digestion of Vinasse in Pilot Plant UASB Reactor

Vinasse from sugar-cane alcohol production is generated in great amounts in Brazil and is disposed on soil “in natura”. Only a few distilleries use mesophilic anaerobic digestion, so far, for gas recovery and vinasse treatment or conditioning, due to an unfavorable economical balance. Thermophilic anaerobic digestion was studied in a large-scale pilot-plant (75 m3 UASB reactor), since vinasses are generated at high temperatures, and no experiments on this subject are reported in the literature, except for a few laboratory assays using pure substrates and other wastewaters. This work demonstrates the feasibility of sugar-cane vinasse thermophilic anaerobic digestion in UASB reactors. The reactor was operated for 280 days, as far as possible like a full-scale plant; at applied organic loading rates of 25-30 kg COD/m3.day, 72% COD removal and 10 Nm3gas/m3.day could be achieved. Granulation of the sludge was essential in order to maintain good stability of the process; almost no soda was necessary for pH control. For full-scale implementation, re-start of the thermophilic process, after several months without feeding, has to be studied yet.