41 research outputs found

    A New Proposal of Cellulosic Ethanol to Boost Sugarcane Biorefineries: Techno-Economic Evaluation

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    Commercial simulator Aspen Plus was used to simulate a biorefinery producing ethanol from sugarcane juice and second generation ethanol production using bagasse fine fraction composed of parenchyma cells (P-fraction). Liquid hot water and steam explosion pretreatment technologies were evaluated. The processes were thermal and water integrated and compared to a biorefinery producing ethanol from juice and sugarcane bagasse. The results indicated that after thermal and water integration, the evaluated processes were self-sufficient in energy demand, being able to sell the surplus electricity to the grid, and presented water intake inside the environmental limit for São Paulo State, Brazil. The processes that evaluated the use of the bagasse fine fraction presented higher economic results compared with the use of the entire bagasse. Even though, due to the high enzyme costs, the payback calculated for the biorefineries were higher than 8 years for all cases that considered second generation ethanol and the net present value for the investment was negative. The reduction on the enzyme load, in a way that the conversion rates could be maintained, is the limiting factor to make second generation ethanol competitive with the most immediate uses of bagasse: fuel for the cogeneration system to surplus electricity production

    A new proposal of cellulosic ethanol to boost sugarcane biorefineries: techno-economic evaluation

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    Commercial simulator Aspen Plus was used to simulate a biorefinery producing ethanol from sugarcane juice and second generation ethanol production using bagasse fine fraction composed of parenchyma cells (P-fraction). Liquid hot water and steam explosion pretreatment technologies were evaluated. The processes were thermal and water integrated and compared to a biorefinery producing ethanol from juice and sugarcane bagasse. The results indicated that after thermal and water integration, the evaluated processes were self-sufficient in energy demand, being able to sell the surplus electricity to the grid, and presented water intake inside the environmental limit for São Paulo State, Brazil. The processes that evaluated the use of the bagasse fine fraction presented higher economic results compared with the use of the entire bagasse. Even though, due to the high enzyme costs, the payback calculated for the biorefineries were higher than 8 years for all cases that considered second generation ethanol and the net present value for the investment was negative. The reduction on the enzyme load, in a way that the conversion rates could be maintained, is the limiting factor to make second generation ethanol competitive with the most immediate uses of bagasse: fuel for the cogeneration system to surplus electricity production2014sem informaçãosem informaçãoThe authors acknowledge the financial support granted by the Agreement Unicamp-Brazil Shell Petroleum Lt

    Effects of concurrent strenght and endurance training sequence order on physical fitness performance in adolescent students

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    The aim of the study was to examine the effect of the sequence order of concurrent training on physical performance in students. 31 subjects were recruited from a Portuguese public high school and were randomly divided in strength training followed by endurance exercise group (GSE, n=12) and endurance followed by strength training group (GAS, n=11). The training program was performed during physical education classes, 2 times per week during 10 weeks. Anthropometrics and physical variables were assessed before (M1), after 5 weeks of training (M2) and after the training period (M3). Training‐induced significant differences in both groups after the training program [1kg and 3kg medicine ball throw gains (GES: 4.6 to 6.3%, and 3.9 to 6.0%, GSE: 5.0 to 9.3% and 3.0 to 8.4%), VO2max (GES: 2.3 to 3.7%, GSE: 2.8 to 8.0%), push-ups (GES: 11.7 to 12.5%; GSE: 13.3 to 23.5%), standing long jump (GES: 5.1 to 4.3%, GSE: 2.9 to 5.3%), counter movement jump (GES: 5.1 to 4.3%, GES: 3.1 to 8.1%) and sprint running 20m (GES: -1.5 to -1.2%, GSE: -1.0 to -1.7%). Independently of the sequence order, concurrent training appear to change body composition and increase physical fitness in students during physical education classes.info:eu-repo/semantics/publishedVersio

    Synthesis and parameter optimization of a combined sugar and ethanol production process integrated with a CHP system

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    The combined sugar and ethanol production process from sugar cane is a paradigmatic application for energy integration strategies because of the high number of hot and cold streams involved, the external hot utility requirement at two temperature levels for juice evaporation and crystallization, and the electricity demand for juice extraction by milling. These conditions make it convenient to combine the sugar-cane process with a CHP system fuelled by bagasse, the main by-product from juice extraction. The strategies, tools and expertise on energy integration developed separately by the research teams authoring this paper are applied here jointly to optimize the synthesis and the design parameters of the process and of the total site starting from the basic idea of dissociating the heat exchanger network design problem from the total site synthesis problem. At first the minimization of the external heat requirement for the process alone is pursued and results show that a one third reduction can be achieved by optimal heat integration. Then the use of the by-product bagasse for on-site power generation is considered and two bagasse-fuelled CHP systems are optimized along with some parts of the sugar and ethanol production process in order to obtain maximum total site net power. Results show a variety of interesting scenarios of combined sugar, ethanol and electricity production plants with considerably high electricity output

    New proposal for production of bioactive compounds by supercritical technology integrated to a sugarcane biorefinery

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    The construction of a supercritical fluid extraction (SFE) plant inside or in close proximity to a sugarcane biorefinery producing first and second generation ethanol demonstrated to be very promising, increasing the economic potential of the SFE process in up to 57 %, since the SFE plant could use directly the ethanol, CO2, heat, and electricity already available, with lower prices. In this study, Brazilian ginseng roots were used as model bioactive compounds source and first the statistical influence of the extraction conditions including pressure (10-20 MPa), temperature (323-363 K), and CO2/ethanol proportion ratio (90:10, 50:50, and 0:100 %, w/w) on the beta-ecdysone content in the extracts was experimentally evaluated and compared with literature results. SFE process evaluated experimentally at the present study showed higher selective extraction for beta-ecdysone from Brazilian ginseng roots, providing an extract with up to 2.16 times higher beta-ecdysone than the results obtained in previous studies. Thermal integration of the SFE process diminished energy requirements of the process, resulting in a reduction of cold utility requirement of 87 % and a final electricity demand of 7.5 kWh/g of beta-ecdysone in the extract. In a situation in which the Brazilian ginseng roots price was increased to 4.71 USD/g, only the SFE integrated with the biorefinery solution would be economically feasible. Finally, the selling of the ginseng roots leftover could be an interesting answer to increase the economical attractiveness of the integrated SFE process to the biorefinery

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    Design of Evaporation Systems and Heaters Networks in Sugar Cane Factories Using a Thermoeconomic Optimization Procedure*

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    Abstract Sugar cane production in Brazil is one of the most competitive segments of the national economy, producing sugar and ethanol for internal and external markets. Sugar production is done basically in several steps: juice extraction, juice clarification and evaporation, syrup treatment and sugar boiling, crystallization, centrifugation and drying. Much heat exchange equipment is used in this process.. An optimized design of the evaporation system with the correct distribution of the vapor bleed to attend other parts of the process may contribute to exhausted steam demand reduction. This paper presents a thermoeconomic optimization of the evaporation system and the heaters network of a sugar factory, aiming at minimum investments and operation costs. Data from Brazilian sugar factories were used to define the process parameters. The methodology proposed is used to evaluate the cost of the steam consumed by the factory and the optimized design of the equipment

    Double-effect distillation and thermal integration applied to the ethanol production process

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    A double-effect distillation system allows a significant reduction in energy consumption, since the condensers and reboilers of different columns can be integrated thermally. To achieve this goal, some columns operate under a vacuum, while others operate close to atmospheric pressure. These pressure levels bring about different temperature levels, allowing energy recovery. Thus, the aim of this study is to assess the incorporation of double-effect distillation in ethanol production, and its impact on energy consumption and electricity surplus production in the cogeneration system. Moreover, because double-effect distillation and thermal integration involve an increase in equipment costs, an economic assessment was done. Several cases were evaluated and a thermal integration technique was applied, in order to integrate the overall process. The thermal integration study showed that it is possible to integrate the juice concentration step (multiple effect evaporation system) in the overall process without additional thermal consumption, through the selection of a suitable set of pressures in the evaporation system. The results showed a reduction in steam consumption of between 17% and 54%, in comparison with the Base Case. Regarding the electricity surplus, this increased by up to 22% when extraction condensing steam turbines were adopted. (C) 2015 Elsevier Ltd. All rights reserved
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