Influencia de la separación de residuos sólidos urbanos para reciclaje en el proceso de incineración con generación de energía

This work analyses the recuperation of the energy of Municipal Solid Waste (MSW) through the incineration process. It considers the up to date tendency of segregation (separation) of plastic, paper and cardboard, glass and metals and their influence in the fluxes of mass and energy in the incineration system of MSW. For its development was used information related to the generation of MSW in Bauru city and the Combust software. The results so obtained allowed the estimation of the Caloric power of the typical MSW and also of this residue when one considers the separations of paper/cardboard and plastic for recycling.

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.

Modelo AC para el despacho combinado de contratos bilaterales y bolsa de energía considerando restricciones de seguridad

Reliability is a key aspect in power system design and planning. Maintaining a reliable power system is a very important issue for their design and operation. Under the new competitive framework of the electricity sector, power systems find ever more and more strained to operate near their limits. Under this new scenario, it is crucial for the system operator to use tools that facilitate an energy dispatch that minimizes possible power cuts. This paper presents a mathematical model to calculate an energy dispatch that considers security constraints (single contingencies in transmission lines and transformers). The model involves pool markets and fixed bilateral contracts. Traditional methodologies that include security constraints are usually based in multistage dispatch processes. In this case, we propose a single-stage model that avoids the economic inefficiencies which result when conventional multi-stage dispatch approaches are applied. The proposed model includes an AC representation of the transport system and allows calculating the cost overruns incurred in due to reliability restrictions. We found that complying with fixed bilateral contracts, when they go above certain levels, might lead to congestion problems in transmission lines.

Viabilidad económica de la utilización de biogás para la conversión en energía eléctrica

The economic viability of the electrical power generation using biogas from swine wastes, was determined. The analyzed biodigester is a continuous tubular model with brick concrete duct and plastic covering with a gasometer, in which the waste of 2.300 fattening pigs are deposited daily. The initial investment estimate for the installation was R$ 51.537, the system annual costs were R$ 5.700, for maintenance, R$ 4.400 for depreciation and R$ 1.370 for interests. It was found that an average consumption of 28 kW-hour-1 is the minimum that the system must reach to be economically feasible.

Coeficiente de operación de un sistema formado por un refrigerador doméstico acoplado a un acumulador de agua caliente para la recuperación de energía

An experimental apparatus containing a domestic refrigerator coupled to a vertical hot water storage tank was used for energy recovery. The original condenser of the refrigerator was maintained, but modified with a concentric tubes heat exchanger with countercurrent water and refrigerating gas flows. The coefficient of performance for the heat pump is calculated by the ratio of energy in the heat storage and the electric power consumed by the domestic refrigerator compressor. The results show that the increasing of hydrostatic pressure in the storage tank increases the water flow rate and the coefficient of performance. The proposed device also reduces the heat dissipation to the surroundings. This is more important in small confinements found in low-cost houses.

Yuca ensilada como fuente de energía para cerdos en crecimiento

Se condujeron dos experimentos para determinar el comportamiento de cerdos en crecimiento, comparando la dieta de maíz-soya con otra de raíz de yuca ensilada con agua o vinaza. Se utilizaron 16 cerdos de cruce comercial alojados en corrales individuales, mediante clasificación simple y dos tratamientos con ocho repeticiones/ tratamiento. En el segundo trabajo se utilizaron 16 animales en similares condiciones, con vinaza para ensilar. No fueron encontradas diferencias significativas para la ganancia diaria (g) y conversión alimentaria (kg kg-1). Se concluye que la raíz de yuca ensilada con agua y yogurt o vinaza, puede sustituir totalmente la energía del maíz para cerdos en crecimiento.