Anaerobic digestion of stillage to produce bioenergy in the sugarcane-to-ethanol industry

Stillage is the main wastewater from ethanol production, containing a high chemical oxygen demand in addition to acidic and corrosive characteristics. Though stillage may be used as a soil fertilizer, its land application may be considered problematic due its high polluting potential. Anaerobic digestion represents an effective alternative treatment to reduce the pollution load of stillage. In addition, the methane gas produced within the process may be converted to energy, which can be directly applied to the treatment plant. The objective of this paper was to investigate the energetic potential of anaerobic digestion applied to stillage in the sugarcane ethanol industry. An overall analysis of the results indicates energy recovery capacity (ERC) values for methane ranging from 3.5% to 10%, respectively, for sugarcane juice and molasses. The processes employed to obtain the fermentable broth, as well as the distillation step, represent the main limiting factors to the energetic potential feasibility. Considering financial aspects the annual savings could reach up to US$ 30 million due to anaerobic digestion of stillage in relatively large-scale distilleries (365,000 m3 of ethanol per year). The best scenarios were verified for the association between anaerobic digestion of stillage and combustion of bagasse. In this case, the fossil fuels consumption in distilleries could be fully ceased, such the ERC of methane could reach values ranging from 140% to 890%. © 2013 Taylor & Francis.

Análise econômica preliminar da implantação de incinerador de resíduos sólidos urbanos na região de Bauru

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Potencial contaminante e energético da vinhaça: riscos de contaminação ao solo e recursos hídricos e recuperação de energia a partir da digestão anaeróbica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desenvolvimento de um sistema para o pré-processamento da cama de frangos de corte destinada a biodigestão anaeróbia e compostagem in-vessel

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desenvolvimento e avaliação de indicadores de eficiência hidraúlica e energética para sistemas de abastecimento de água como ferramenta de suporte à tomada de decisões

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação experimental de eficiência térmica de um recuperador de calor e caldeira em um sistema de cogeração

Pós-graduação em Engenharia Mecânica - FEB

Cidades sustentáveis: análise comparativa com cidades contemporâneas

Currently the world is under an energy revolution, every day more technologies are developed in order to better use the energy for having better energy efficiency of equipment and processes with minimal environmental degradation. Taking into account that thousands of people live in built environments in the context of cities and that the energy flow to this location is significant, it is important to study the built environment as a potential source of savings, energy recovery and regeneration, because cities are the major bottlenecks energetic. Therefore, this study aimed to examine and to list the most important and promising technologies to be used in the built environment to collect or save energy that would be wasted, such as clothes that generate energy through movement or solar incidence, facades of buildings that generate energy due to solar radiation, fitness centers that produce electricity due to the rotation used in fitness equipment for athletes, elevators that take advantage of the potential energy or use it more rationally, generators that take advantage of energy vibrational, and finally more sustainable vehicles with higher performance and less degrading the environment. The information and results obtained from this study show that the technologies used to harness energy before lost are increasingly evident and also is increased the progress relative to the energy use in a urban context. In the closure, a comparison of energy expenditure between a city that uses some of these sustainable technologies and another of the same size with conventional habits is presented

Avaliação da auto-suficiência energética em reatores anaeróbios aplicados ao tratamento de resíduos da indústria de produção do etanol

Ethanol, the main automotive biofuel, has its production based on the fermentation of sugars found in biological materials and on the distillation of the alcoholic media formed during the fermentative process. Stillage is the main residue from ethanol production, containing a high organic loading in addition to acidic and corrosive characteristics. Considering the available technologies to treat stillage, we highlight anaerobic digestion, which allows the reduction of the impacts associated to pollutants loading of this effluent and the generation of energy from the methane gas produced in the process. Based on the high treatment efficiency usually associated to the anaerobic process, this work aimed to assess whether anaerobic systems applied to the treatment of stillage are energetically self-sufficient. First we evaluated the energy recovery capacity in an anaerobic reactor applied to the treatment of stillage resulting from corn-to-ethanol processing. The results indicated the great influence that a correct selection of electrical equipment and their respective operating periods have on the net energy balance of the anaerobic treatment. The high energy consumption of the heater would not allow the system to achieve a positive net energy balance – the maximum energy recovery would reach only 0.68% of the consumption. However, the replacement of the mixture equipment would result in energy gains ranging from 8.5 to 967.9% of the consumption. In this work we also assessed the efficiency of methane yields for a few studies and the correlation between some parameters of the anaerobic process. With respect to the methane yield, we noted that mesophilic systems tend to be more advantageous than the thermophilic ones (efficiency of 76.45 ± 22.51% vs. 69.40 ± 30.36%). Considering the study... (Complete abstract click electronic access below)

Aproveitamento energético de resíduos de esgotamento sanitário

This paper presents alternatives for waste energy recovery from the sewage of cities. Through a review of the literature it is observed that the technologies studied are usually turbines, microturbines, and engines adapted to the use of biogas. For project design analyzes the technologies found in some sewage treatment plants in Brazil and the world, compared with those found in the literature. With this study it can be concluded that the most used technologies are microturbines and motor generator sets, which are already implemented in some locations in the USA, Europe and even Brazil. It can also be concluded that the energy recovery of waste from sewage can enable design of wastewater treatment plants thereby contributing to improved quality of life

Implementação de um tuboexpansor na refinaria do Planalto Paulista – REPLAN com objetivo do aproveitamento da energia contida nos gases residuais do FCC – Fluid Catalytic Cracking na geração de energia elétrica

The steel type AISI 4130 (ultra-high strength steel) is an alloy of low carbon and its main alloying elements are chromium and molybdenum, which improves the toughness of the weld metal. It has numerous applications, especially where the need for high mechanical strength. It is widely used in equipment used by the aviation industry, such as cradle-tomotor, and this is the motivation for this study. Cots are of fundamental importance, because the engine supports and maintains balance in the fixed landing gear. This equipment is subjected to intense loading cycles, whose fractures caused by fatigue are constantly observed. Will be determined the effects caused by re-welding the structure of aeronautical equipment, and will also study the microstructure of the metal without welding. The studies will be done on materials used in aircraft, which was given to study. The results provide knowledge of microstructure to evaluate any type of fracture that maybe caused by fatigue. Fatigue is a major cause of aircraft accidents and incidents occurred, which makes the study of the microstructure of the metal, weld and re-solder the knowledge essential to the life of the material. The prevention and control of the process of fatigue in aircraft are critical, since the components are subjected to greater responsibility cyclic loading

Avaliação da auto-suficiência energética de reatores anaeróbios no tratamento de esgoto sanitário e de água preta

The purpose of this project is to verify whether anaerobic reactors applied to sewage treatment are energetically self-sufficient. This evaluation can be made by balancing the methane produced through the anaerobic transformation stages (hydrolysis, acidogenesis, acetogenesis and methanogenesis) and the reactor energy consumption requirements. The original project included methanogenic activity tests, which could not be performed due to setbacks in the installation of an analytical instrument. Scientific articles about bench- and full-scale anaerobic reactors were investigated instead. An average substrate-to-methane conversion efficiency of 58,2±18,6% was found for the bench-scale reactors and higher efficiencies (89,2%) were found for the cases which had higher Organic Loading Rates (OLRs) values. The average energy output was 0,013 kWh/Lsewage, value unable to meet the energy needs for the reactor operation, considering equipments normally used such as temperature controller. This balance can become positive if few hypotheses are made, for example (i) to eliminate the use of temperature controller (ii) to alter the operation pattern from continuous to intermittent. Based on energy balance assessment of eight bench-scale reactors, it was observed that the implementation of a system for biogas utilization is not energetically feasible. However, interesting results were found for a full-scale sewage treatment plant, ETE Ouro Verde – Foz do Iguaçu, PR, Brazil. Even though its substrate-tomethane conversion efficiency was about 10% only, the energy balance was quite positive, with energy consumption of 68 kWh/month and energy production of 660 kWh/month. This analysis leads us to conclude that energy recovery from full-scale sewage treatment plants should be practiced by other plants

Coleta de informações para projeto de incinerador regional de resíduos sólidos urbanos (RSU)

The incineration of municipal solid waste has become a very interesting, in order that incineration reduces the amount of solid waste, which would be accumulated in dumps and / or landfill. Furthermore, it is possible to generate electrical energy by use of clean well known technology. To verify the feasibility of installing a plant for the incineration of solid waste with energy recovery, we must consider some basic requirements. For this reason, will be presented in this paper some factors that influence the project to install a plant of incineration with energy recovery.

Análise da viabilidade do uso de biogás gerado a partir de dejetos bovinos em microturbinas para fins de geração, cogeração e trigeração de energia

The use of digesters has become an important alternative for the proper disposal of organic agricultural wastes, serving as a solution to some environmental and health problems. Furthermore, the process of digestion provides commercially valuable by products such as biogas and bio fertilizer. The generation of biogas from agricultural waste, and its use in power generation systems has aroused great interest in rural areas because it enables supply in whole or in large part the energy demand of ownership by reducing production costs. The advent of technology has brought new forms of energy conversion of biogas, as the use of micro turbines specifies to be fuelled with biogas derived from the decomposition of organic matter in digesters, since it has a low level of methane in its composition, and high degree of impurities such as hydrogen sulphide, which are harmful to equipment and reduce the calorific value of biogas. The use of micro turbines behind other advantages like low emissions, great fuel flexibility and low maintenance. This paper presents an analysis of the feasibility of using biogas generated from cattle manure in micro turbines to generate electricity. Behind also an assessment of the energy potential that each animal has on various uses of biogas, and forms of energy recovery from the exhaust gases of the micro turbine. Also conducts an evaluation of the energy savings that the use of biogas aggregates properties.

Projeto preliminar de cogeração aplicado a um forno de produção de vidro plano

The objective of this paper is to realize the preliminary cogeneration project, to be applied on the output of a float glass furnace, aiming the energetic use of the furnace's by-products in other relevant applications on the site. It was analyzed the main points where the cycle could be installed and also the available technologies to energy recovery. After, it was chosen the installation point and the technology to be projected, evaluated the electric power generated and the cycle efficiency. Finally it was evaluated economical indicators in order to verify the project's economical feasibility

Procedimento para homologação de sistemas ecoeficientes para obtenção de créditos de carbono

This paper deals with the homologation process for obtaining carbon credits through the Clean Development Mechanism (CDM), that regulates the greenhouse gases reductions under the rules of the Kyoto Protocol. The CDM evaluates projects through a project cycle, which begins with the preparation of the Project Design Document (PDD) until the project certification to receive Certified Emission Reductions (CERs), popularly known as carbon credits. This study analyzed the implementation of the system Burner Recorder System for Low Flows of Biogas (QRBBV), developed by Marcelino Junior & Godoy (2009), in an eco-friendly wastewater treatment mini-plant (miniEETERA), built at the site of UNESP - Guaratinguetá SP. The QRBBV system is low cost and high reliability, developed to burn the methane generated at sites of low and variable production of biogas, which is not economically justified their energy recovery. Currently, almost all wastewater generated at the site of the campus is being treated by miniEETERA and, as a result, the biogas originated by this activity is being released into the atmosphere. Therefore, the project activity aims to capture and burn the biogas generated by miniEETERA, reducing the negative effects caused by the methane emissions into the atmosphere and, thus, claim to receive carbon credits. This work aimed to demonstrate the project applicability under CDM through the study and preparation of the PDD, as well as an analysis of the entire project cycle required for homologation. The result of the work obtained an estimate of only 20 CERs per year and proved to be economically unviable for approval through the CDM, since the spending with the approval process would not be compensated with the sale of CERs, mainly due the low carbon price in the world market. From an environmental standpoint, the project is perfectly... (Complete abstract click electronic access below)