Search

In the Cerrado-Amazonian ecotone in the State of Mato Grosso, intensely altered by anthropic action, the knowledge and processes of energy conversion and energy balance are still incipient, making the monitoring and modeling of diffuse radiation essential for several applications. The objective of this study was to evaluate the seasonality of the diurnal evolution and estimate the hourly diffuse radiation ( H d h) and incident radiation in the horizontal plane between June 2011 and October 2016. The instantaneous measurements (5 min) of diffuse radiation underwent geometric, astronomical, and anisotropic corrections, with subsequent hourly integrations. The seasonality of diffuse radiation and its radiometric fractions was evaluated. The estimates were made considering total and seasonal data groupings (water stations in the region) and in different cloudiness classes (atmospheric transmissivity index— K T h ). The diurnal behavior of diffuse radiation ( H d h ) was similar to that of global radiation and at the top of the atmosphere, with maximum values at solar noon. The correlations between K d h and K T h showed third-order polynomial behavior, with maximum observed values of K d h ranging from 0.8 to 0.9, for K T h less than 0.2. Estimation equations based on radiometric fractions underestimated the values of diffuse radiation, with a better performance presented by models adjusted in annual data groupings. Among the parameterized models for estimating diffuse radiation obtained in the literature, those calibrated regionally in this study, together with those developed for tropical regions, presented better statistical performances. [ABSTRACT FROM AUTHOR]

The energy balance constitutes a powerful management instrument for government agencies, as it offers an overview of the energy situation of the country (or region) and serves as a guide for energy policies and monitoring of these policies. Although Brazil has published the national energy balance for more than half a century, the national publication does not adequately address energy statistics at the level of the states. This occurs either due to the lack of specific data or the absence of total disaggregation. Accordingly, the elaboration and implementation of public policies for the energy sector in the Brazilian states lack consistent energy statistics. Therefore, this paper aims to present a model for the Brazilian states to elaborate the energy balance. The proposed model consists of applying internationally referenced methodologies to develop a user-friendly software, which includes automatic energy unit conversions, different chart styles, high-level data organization, and Sankey diagrams. As a result, the software can be adopted by local governments as a tool to maintain the state energy balance publication periodically, and hence obtain the detailed information necessary to manage and formulate energy policies. The advantage of the software is that it can be operated by non-experts and the energy flow as well as the entire report can be generated automatically. The proposed software was successfully used to generate the energy balance of the Mato Grosso do Sul state. [ABSTRACT FROM AUTHOR]

The Rio Grande Rise (RGR) is a plateau located at 31°S in the Southwestern Atlantic, rising from 5916 m up to 161 m below the sea level. The RGR is an important site for future mining of Fe-Mn crusts and can lead to an expansion of Brazil's Exclusive Economic Zone. The Cruzeiro do Sul Rift (CSR) fault cuts through the RGR from southeast to northwest. In this study we characterize the RGR circulation, showing that M2 tides are the main source of variability in the region, with an amplitude that can reach 0.3 m s−1, larger than the mean flow. These M2 tides are dominated by the baroclinic component and intensified near the bottom. The generation of M2 internal tides occurs mainly in the CSR slopes, with most energy converted from the barotropic tide being radiated away in the form of tidal beams. In addition, the impingement of the mean southern South Equatorial Current and tidal rectification generates anticyclonic circulations around the RGR peaks, with the latter mechanism being responsible for a bottom intensified anticyclonic circulation of 0.2 m s−1. Finally, our results reveal that the RGR is a hotspot of internal tide generation in the Southwestern Atlantic. • Most barotropic to baroclinic tide energy conversion occurs on the rift slopes. • 47.1% of the baroclinic energy converted from barotropic tides is radiated away. • Tidal rectification is the primary mechanism of generating bottom intensification. [ABSTRACT FROM AUTHOR]

Biomass ranks third as the greatest energy source for the conversion of electricity in Brazil, with sugarcane as the most relevant energy input. Bagasse is the residual biomass in the crushing process and its storage is required due to the production´s seasonality. Experiments have been undertaken for samples of stocked material in different positions (differentiated degradation) obtained in an agro-industrial unit with seventy thousand tons acquired for use in a steam boiler. Physical and chemical (immediate analysis, including humidity) and energetic (heat power) characteristics of sugarcane bagasse were evaluated when undergoing stocking conditions in the open air during three years. Climate influence and storage conditions were analyzed in alterations of the energy potential of residual biomass. The following results are underscored: a) specific mass was four times higher and TUM,BU reached 85% when bagasse was stored in the open air; b) decrease of TCZ (< 1%), making possible reduced damage and maintenance when used in steam boilers; c) without significant degradation as solid fuel with regard to TMV,BS and TCF,BS, provides respectively ignition and stability of fuel, and significant contribution in PCS; d) mean rates for calorific power will be consumed at 15% or more, within the process of bagasse drying; e) available thermal energy (-27 mil TEP) has a significant potential for the co-generation of energy and increase in aggregated value of agro-industrial production. [ABSTRACT FROM AUTHOR]

This study sought to characterize sludge digested in Upflow Anaerobic Sludge Blanket (UASB) reactors during the drainage process of Drying Bed Sludge (DBS) to conduct a Life Cycle Assessment (LCA) for different DBS disposal scenarios. In addition, the potential recovered energy from the waste material was verified when submitted to Anaerobic Digestion (AD) or when combusted through simulation software SimaPro®. Laboratory analyses were conducted with the collected samples from a wastewater treatment plant in Itajubá, Minas Gerais, Brazil. The calorific value, ashes generated from the burning process, and methane production were conducted in two experiments for a qualitative and quantitative evaluation of the biogas generated. The scenarios included DBS disposal in landfills and ditches, DBS biodigestion, and combustion. The methane yield generated by DBS resulted in a lower value compared to DBS produced by the UASB reactor disposal system. The LCA results show that the impact category pertaining to global warming is indeed influenced for all scenarios, almost entirely comprised of biogas emissions coming from the drying bed waste. Heavy metal emissions may occur during combustion, which may impact human toxicity. Under the scenario in which DBS undergoes biodigestion, the pollutants include nitrogen oxide, sulfur monoxide, and carbon monoxide. [Display omitted] • Methane production and the energy recovery from anaerobic sludge were evaluated. • Life Cycle analysis was conducted using data obtained in laboratory tests. • Sludge incineration presented a higher energy generation than anaerobic digestion. • Incineration showed the best results for all impacts, except human toxicity. [ABSTRACT FROM AUTHOR]

Energy production needs to increase in order to meet population and industrial growth in the coming decades, and clean energy that promotes the reduction of polluting gases in the atmosphere is required. Sugarcane is a crop with great potential for bioenergy production due to its high potential for converting solar energy into biomass. In this context, the questions arise: What is the real efficiency of conversion solar energy into biomass by sugarcane? How can the production environment and genetic diversity influence this process? In this sense, the objective of this work was to evaluate the efficiency of the conversion of solar energy into biomass, as well the available energy per hectare, and the productivity of stalks as a function of the production environment in different cultivars. The experiments were carried out in two production environments in Brazil, Prado Ferreira, Paraná State (Production Environment A) and Presidente Bernardes, São Paulo State (Production Environment C) and with three sugarcane cultivars SP80-3280, RB855156 and RB867515 in two cultivation cycles. This study showed: a) the production environment × genotype interaction causes 75.80% variation in stalk productivity; b) biomass productivity is less affected by water deficit than stalk productivity; c) the energy conversion efficiency (ECE) ranged from 2.80 to 4.54% in plant cane and 2.10–3.87% in ratoon cane cycles. The variation of ECE in the production environments was due to four main factors: greater water availability, soil fertility, air temperature and solar radiation. • Stalk yield can vary by 75.8% depending on the production environment. • Biomass yield is less impacted than stalk yield depending on the production environment. • Higher air temperature can reduce sugarcane yield. • Higher solar radiation is not associated to higher yield and energy conversion. • Solar energy conversion can increase by 51.3% with the correct management cultivar x environment. [ABSTRACT FROM AUTHOR]

Abstract: The generation of waste is an intrinsic characteristic of forestry and agricultural production and has become a major concern. Brazil is a great agricultural producer, and in recent years both the planted area and crop production have grown significantly, with a corresponding increase in agricultural waste. In the context of climate change, efficiency and energy security, it is fundamental to develop alternative energies that meet the needs of both the energy supply and sustainable development. Wood chips and coffee husks are low cost residues and potentially capable of generating heat, steam and electric power, thus they can serve as an alternative fuel for generating energy. This work aims to relate the agricultural market to the energy market, using waste from coffee and eucalyptus production to generate energy, as well as mapping waste production in Brazil by region. It was observed that Brazil has a great capacity to generate alternative energy, since approximately 11.4×106 t of wastes are generated per year from coffee and eucalyptus production alone. These wastes can be used for the thermochemical conversion of energy via gasification, with potential to generate a total of 201.3PJ. [Copyright &y& Elsevier]

Abstract: In the present work, selected agroindustrial solid residues from Brazil – biosolids from meat processing wastewater treatment and mixture of sawdust with these biosolids; residues from apple and orange juice industries; sugarcane bagasse; açaí kernels (Euterpe oleracea) and rice husk – were characterised as solid fuels and an evaluation of their properties, including proximate and ultimate composition, energy content, thermal behaviour, composition and fusibility of the ashes was performed. The lower heating value of the biomasses ranged from 14.31MJkg−1 to 29.14MJkg−1, on a dry and ash free basis (daf), all presenting high volatile matter content, varying between 70.57wt.% and 85.36wt.% (daf) what improves the thermochemical conversion of the solids. The fouling and slagging tendency of the ashes was predicted based on the fuel ash composition and on the ash fusibility correlations proposed in the literature, which is important to the project and operation of biomass conversion systems. The potential for application of the Brazilian agroindustrial solid residues studied as alternative energy sources in thermochemical processes has been identified, especially concerning direct combustion for steam generation. [Copyright &y& Elsevier]

Aiming at evaluating the effect of the cultural practices soil management and crop rotation on energy conversion and balance, an experiment was conducted in Passo Fundo, Rio Grande do Sul, Brazil, from 2004 to 2009. Four types of soil management were used: 1) no-tillage, 2) minimum tillage, 3) conventional tillage using disk plow, and 4) conventional tillage using moldboard plow and three crop rotation systems: system I - wheat/ soybean; system II - wheat/soybean and common vetch/sorghum; and system III - wheat/soybean, common vetch/sorghum, and white oats/soybean. The experimental design was made with randomized blocks, with split-plots and three replications. The main plot consisted of the soil management systems, while the split-plots consisted of the crop rotation systems. Energy conversion (available energy/consumed energy) and balance (available energy - consumed energy) in a six-year period were discussed in this paper. The sorghum was the crop that showed the highest energy return in comparison to the other crops. The no-tillage system showed higher energy conversion and balance (15.27 and 42,391 Mcal ha-1) than the minimum tillage (12.82 and 35,217 Mcal ha-1) and the conventional tillage systems using disk plow (10.64 and 28.988 Mcal ha-1) and moldboard (10.55 and 28,698 Mcal ha-1). The wheat under crop rotation tended to be more energetically efficient than the monoculture of this cereal. [ABSTRACT FROM AUTHOR]

Abstract: In Brazil the widespread use of electrical showerheads for providing hot water for domestic consumption contributes to a load curve that peaks in the early evening, imposing a considerable burden to generation, transmission, and distribution utilities. On average, over 73% of Brazilian households use these 3–8kW electrical resistance showerheads. In some of the more temperate climate regions in the south of the country, where most of the Brazilian population is concentrated, electrical showers are present in over 90% of residential buildings. For the residential consumer, while these high-power heating devices are the least-cost investment alternative, they lead to high running energy costs. Furthermore, due to their very low load factor (typically below 2%), each of these high-power showerheads results in considerably low return on the high investment costs in terms of infrastructure for the electricity sector. Particularly in low-income dwellings, electrical showerheads represent by far the highest electrical loads, resulting in a considerable component in the monthly energy bill. On the other hand, Brazil is one of the sunniest countries in the world, and solar water heating technologies have demonstrated large financial benefits and short payback times. Due to their comparatively higher initial investment costs, however, domestic solar water heaters are used mostly in higher income residences. In this work we present the potential of a low-cost version of the typical domestic solar water heating system for low-income dwellings, where the electrical resistance, which is normally installed inside the hot water tank, is replaced by a variable power electrical showerhead. This design avoids the use of electrical power as auxiliary heating for the whole of the boiler volume, since only the water which passes through the showerhead might be heated by the electrical resistance. This system configuration is a commercially available low-cost solar water heater option. A case-study is presented for a statistically representative group of low-income dwellings with solar water heating systems in Florianópolis – Brazil. Our results show that the economies obtained are considerable, both in terms of energy consumption (kWh) and peak demand (kW) reduction. When compared with higher income typical users of solar water heating technologies, these economies represent a relatively higher benefit, both for the low-income population, as well as for the utilities involved. Our results also show that the avoided power costs, a benefit for the distribution utility company, might be more substantial than the avoided energy costs, a benefit for the end user. In the energy constrained on-peak hours period, the utility company might benefit from being able to sell this energy to other higher paying tariff consumers. [Copyright &y& Elsevier]

The demand for food, fuel, and energy resources continues to increase worldwide. Currently, there are many international efforts aimed at finding renewable, sustainable, and environment friendly solutions for these problems. The spiraling price of petroleum and the adverse effects of using nonrenewable resources are major reasons for increased interest in renewable sources of energy. Brazil, the fifth largest and fifth most populated country in the world, has been developing successful initiatives in renewable sources of energy for more than 75 yr. The production and use of ethanol from sugarcane (Saccharum L.) is a global model for ethanol production, distribution, and use; therefore, the Brazilian ethanol industry has attracted interest from scientists, producers, and governments of both developed and developing countries. Like ethanol, biodiesel is also receiving increased interest in Brazil, with the source material for biodiesel production varying widely between regions. Several oleaginous species have been used, and others are being investigated as potential sources for biodiesel production. Biodiesel was introduced much later than ethanol in Brazil with the formation of the Brazilian Energy Matrix in January 2005 and a mandatory use of at least 2% (B2) biodiesel by 2008 and 5% (B5) by 2013. This paper presents a view of the historic development of ethanol and biodiesel programs in Brazil, emphasizing the strategic role of plant genetic resources as a pillar to support future improvements through plant breeding. [ABSTRACT FROM AUTHOR]

reFOCUS looks at some some cutting edge BioFuel processing technologies (below); and the country case study on page 52 charts Brazil''s progress to date as it strives to overcome its difficulties and develop a major biodiesel program ripe for export. [Copyright &y& Elsevier]

Coffee production in Brazil creates significant amounts of residues. The goals of this study are to evaluate the characteristics of these residues (parchment, husk, pulp, spent grounds, silverskin and defective beans); to discuss their potential for conversion to improved biofuels via thermochemical methods; and to develop mass and energy balances of the processes to help determine the value of residues for direct combustion, fast and slow pyrolysis, gasification, hydrothermal carbonization and torrefaction. Particularly the pulp, but also husk and parchment, are characterized by high moisture, as well as high contents of cellulose (41–64%) and hemicellulose (27–35%). These residues are suitable for several conversion routes, albeit with the drawback of drying need for the dry methods. The ash of these also creates a risk of fouling, corrosion and agglomeration with high-temperature and fluidized bed technologies. The silverskin and some of the defective beans are available at lower moisture. The spent coffee grounds appear a particularly advantageous residue for energy use: while moisture varies, the roasted product dries easily and has the highest heating value of the residues. For defective beans, little thermochemical treatment data is available. Among the technologies, for wet feedstocks hydrothermal carbonization has the advantage of post-conversion drying. Gasification appears advantageous for parchment with a high syngas yield and heating value. Fast pyrolysis of biomass suffers from the oxygen content of the liquid, requiring additional treatment; slow pyrolysis may be more appropriate. In conclusion, coffee residues have potential as feedstocks for a number of thermochemical conversion processes. Image 1 • Brazil is the largest producer and exporter of coffee worldwide. • Coffee agroindustry is responsible for a considerable side stream of residues. • Agricultural policy in Brazil has increasingly focused on sustainable development. • Thermochemical technologies are potential conversion routes for energy generation. [ABSTRACT FROM AUTHOR]

Rural sanitation is still a challenge in developing countries, such as Brazil, where the majority population live with inadequate services, compromising public health and environmental safety. In this context, this study analyzed the demographic density of these rural agglomerations using secondary data from the Brazilian Institute of Geography and Statistics (IBGE). The goal was to identify the possibilities associated with using small-scale upflow anaerobic sludge blanket (UASB) reactors for sewage treatment, mainly focusing on biogas production and its conversion into energy for cooking, water heating and sludge sanitization. Results showed that most rural agglomerations lacking the appropriate sewage treatment were predominant from 500 to 1500 inhabitants in both northern and southern Brazilian regions. The thermal energy available in the biogas would be enough to sanitize the whole amount of sludge produced in the sewage treatment plants (STPs), producing biosolids for agricultural purposes. Furthermore, the surplus of thermal energy (after sludge sanitization) could be routed for cooking (replacing LPG) and for water heating (replacing electricity) in the northern and southern regions, respectively. This would benefit more than 200,000 families throughout rural areas of the country. Besides the direct social gains derived from the practice of supplying biogas for domestic uses in the vicinity of the STPs, there would be tremendous indirect gains related to the avoidance of greenhouse gas (GHG) emissions. Therefore, an anaerobic-based sewage treatment may improve public health conditions, life quality and generate added value products in Brazilian rural areas. [ABSTRACT FROM AUTHOR]

Brazil embarked on an ambitious fuel program in the early 70s to exploit greater use of ethanol as a transport fuel. Though the road has been a rocky one, today the country offsets the need to consume a significant amount of fossil fuels via the use of ethanol. Paul Grad provides an overview of the past and current situation in this sector and its potential for more widespread adoption in the energy mix. [Copyright &y& Elsevier]