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Made available in DSpace on 2018-11-26T17:41:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-12-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Biomass Integrated Gasifier/Gas Turbine Combined Cycle (BIG/GTCC) systems in the sugarcane industry, are capable to produce more electricity per unit of biomass consumed than the conventional Condensing Extraction Steam Turbine (CEST) systems. A technical analysis of the introduction of BIG/GTCC technology in the sugarcane industry for electricity and heat generation, using wet sugarcane bagasse as fuel, was conducted. For sugar plants, with large steam requirements, the implementation of the pure BIG/GTCC is not convenient due to the size of the required gas turbine and of the gasification island. The partial BIG/GTCC appear to be better alternative, by the combination of the torrefaction pretreatment and entrained flow gasifier, CHOREN Carbo-V type, permitting a net electricity generation efficiency of 14.7% and the increment of the CEST cogeneration efficiency;, using wet sugarcane bagasse as feedstock. This arrangement avoid Observed problems in previous experiences with the continuum handling and feeding of shredded sugarcane bagasse to the gasifier. (C) 2017 Elsevier Ltd. All rights reserved. Sao Paulo State Univ, Fac Engn Guaratingueta, Energy Dept, Sao Paulo, Brazil Sao Paulo State Univ, Fac Engn Guaratingueta, Energy Dept, Sao Paulo, Brazil CNPq: 165937/2015-7 CNPq: 403366/2015-1

This work present a novel primary method, for tar reduction in downdraft gasification. The principle of this new technology is to change the fluid dynamic behaviour of the mixture, formed by pyrolysis product and gasification agent in combustion zone; allowing a homogeneous temperature distribution in radial direction in this reaction zone. To achieve the change in the fluid dynamic behaviour of the mixture; the entry of gasification agent to combustion zone is oriented by means of wall nozzles in order to form a swirl flow. This modification in combination with the extension of the reduction zone, will allow, to increases the efficiency of the tar thermal cracking inside the gasifier and the extension of the Boudouard reactions. Consequently, the quantity of tar passing through the combustion zone without cracking and the concentration of tar in the final gas, decrease significantly in relation with the common value obtained for this type of reactor, without affecting significantly the heating value of the producer gas. In this work is presented a new design for 15 kW downdraft gasification reactor, with this technology implemented, the tar content obtained in the experiments never overcome 10 mg/Nm 3 , with a lower heating value of 3.97 MJ/Nm 3 .

In the recent years the fuel cells have received much attention. Among various technologies, the Proton Exchange Membrane Fuel Cell (PEMFC) is currently the most appropriate and is used in several vehicles prototype. A comparative technical, economical and ecological analysis between an Internal Combustion Engine fueled with Diesel driving an electricity Generator (ICE-G) and a PEMFC fed by hydrogen produced by ethanol steam reforming was performed. The technical analysis showed the advantages of the PEMFC in comparison to the ICE-G based in energetic and exergetic aspects. The economic analysis shows that fuel cells are not economic competitive when compared to internal combustion engine driving an electricity generator with the same generation capacity; it will only be economically feasible in a long term; due to the large investments required. The environmental analysis was based on concepts of CO2 equivalent, pollution indicator and ecological efficiency. Different to the ICE-G system, the Fuel Cell does not emit pollutants directly and the emission related to this technology is linked mainly with hydrogen production. The ecological efficiency of PEMFC was 96% considering the carbon dioxide cycle, for ICE-G system this parameter reach 51%.

Fuel cells are electrochemical energy conversion devices that convert fuel and oxidant electrochemically into electrical energy, water and heat. Compared to traditional electricity generation technologies that use combustion processes to convert fuel into heat, and then into mechanical energy, fuel cells convert the hydrogen and oxygen chemical energy into electrical energy, without intermediate conversion processes, and with higher efficiency. In order to make the fuel cells an achievable and useful technology, it is firstly necessary to develop an economic and efficient way for hydrogen production. Molecular hydrogen is always found combined with other chemical compounds in nature, so it must be isolated. In this paper, the technical, economical and ecological aspects of hydrogen production by biogas steam reforming are presented. The economic feasibility calculation was performed to evaluate how interesting the process is by analyzing the investment, operation and maintenance costs of the biogas steam reformer and the hydrogen production cost achieved the value of 0.27 US$/kWh with a payback period of 8 years. An ecological efficiency of 94.95%, which is a good ecological value, was obtained. The results obtained by these analyses showed that this type of hydrogen production is an environmentally attractive route.

In this chapter, thermodynamic studies are conducted for determining the energy efficiencies of each type of hydrogen production process. In the case of the steam reforming processes, a physicochemical analysis was previously conducted, which was based on the concepts of Gibbs free energy, equilibrium constant, and degree of advancement. In light of pressure and temperature conditions, the energy efficiency levels of such processes are determined. In the case of hydrogen production from renewable electrolytic processes, it was based on the electrolyzer’s efficiency and the average efficiencies of wind, photovoltaic, and hydroelectric power plants. In the case of algae, it was considered the energy contained in the hydrogen being produced and the energy consumption levels during the periods of growth, adaptation, and hydrogen production.

This chapter discusses the state-of-the-art in terms of hydrogen production processes. At first, the steam reforming reactions of ethanol, biogas, and natural gas are introduced. A study on the catalysts being used in the selected reforming processes is also presented with their respective operating temperatures, feed molar ratio, and conversion rates of reagents. Afterwards, the electrolysis process and types of electrolyzers are presented with the renewable energy sources required for such, as well as the settings adopted for this type of hydrogen production processes. This chapter is concluded with the presentation of the biological hydrogen production process from green algae, with the description of the alga strain and methodology for determining the amount of hydrogen produced.

As hydrogen production is not a clean process in its separation (from acid, methane, hydroxide, water, alcohol, etc.), there are energy requirements, thus resulting in pollutant emissions along its production process.

There are more than ten methods for an economic analysis of energetic systems. Each researcher chooses their own suitable methodology. In the case of hydrogen production processes, there is the need to use a method that permits a comparison of the cost of hydrogen production considering all the processes studied in the previous chapter.

The purpose of this paper is to describe the benefits of sugar cane ethanol in Brazil, appointing the productivity of this type of fuel based on hectares of plantation, its carbon dioxide cycle and the contribution to reduce the greenhouse effect. In the following step the uses of ethanol for hydrogen production by steam reforming is analyzed and some comparison with natural gas steam reforming is performed. The sugar cane industry in Brazil, in a near future, in the hydrogen era, could be modified according to our purpose, since besides the production of sugar, and ethylic and anhydric alcohol, Brazilian sugar cane industry will also be able to produce biohydrogen. Fuel cells appear like a promising technology for energy generation. Among several technologies in the present, the PEMFC (proton exchange membrane fuel cell) is the most appropriate for vehicles application, because it combines durability, high power density, high efficiency, good response and it works at relatively low temperatures. Besides that it is easy to turn it on and off and it is able to support present vibration in vehicles. A PEMFC’s problem is the need of noble catalysts like platinum. Another problem is that CO needs to be in low concentration, requiring a more clean hydrogen to avoid fuel cell deterioration. One part of this paper was developed in Stockholm, where there are some buses within the CUTE (clean urban transport for Europe) project that has been in operation with FC since January 2004. Another part was developed in Guaratingueta ´ , Brazil. Brazil intends to start up a program of FC buses. As conclusion, this paper shows the economical analysis comparing buses moved by fuel cells using hydrogen by different kinds of production. Electrolyze with wind turbine, natural gas steam reforming and ethanol steam reforming.

Background Several neurological diseases, especially different types of peripheral neuropathy (PN) are common in inflammatory bowel disease (IBD). Methods We prospectively evaluated the presence of PN in 121 patients with IBD (51 with Crohn's disease [CD] and 70 with ulcerative colitis [UC]) and 50 controls (gastritis and dyspepsia) over 3.5 years. Results A total of 15 patients (12.4%) with small-fiber neuropathy and IBD (7 CD and 8 UC) and 24 patients (19.8%) with large-fiber PN (12 CD and 12 UC) were diagnosed. Small-fiber neuropathy affected 6% and large-fiber PN affected 4% of the control patients. Patients with CD with PN were older, had more metabolic complications and more severe motor involvement than patients with UC with PN. Carpal tunnel syndrome was more common in patients with UC. Sural and median sensory nerves were the most commonly and severely affected sensory responses. Tibial, peroneal, median, and ulnar compound muscle action potential amplitudes were also significantly decreased in patients with CD and UC. In general, sensory and motor amplitudes were a more sensitive marker for PN in patients with IBD than conduction velocities. Conclusions In summary, PN is common in patients with IBD. It may be primarily related to IBD, phenotypically modified by metabolic complications. Its phenotype is diverse (most commonly small to predominantly axonal sensory large-fiber), but usually more severe in CD. It also includes ataxic and demyelinating forms. Results from our 10-year follow-up will elucidate the PN clinical course and the real impact of the comorbidities and new therapies.

Global warming is caused mainly by the excessive use of fossil fuels (coal, oil, diesel, gasoline, etc.) that emit millions of tons of pollutants into the environment. Besides, the fact that these fossil fuels are nonrenewable resources promotes the research in cleaner energy sources. In this chapter are presented two different technologies that could be introduced in the sugarcane industry to generate electricity and other kinds of clean fuel (producer gas and hydrogen); the case of hydrogen production by ethanol steam reforming and biomass gasification, which appear like promising technologies for energy generation in the sugarcane industry. Currently, most hydrogen is obtained from natural gas through a process known as reforming. Other technologic alternatives that may improve the supply of energy to the sugarcane industry is the use of biomass gasifiers in association with cogeneration system utilizing combined cycles to produce simultaneously electricity and heat, a technology known as Biomass Integrated Gasification/Gas Turbine Combined Cycle (BIG/GTCC). Cogeneration, has been accepted by different industries and has gained great application in the sugarcane industry, where the thermic and electric demands are favorable to use this type of energy system. The main fuel used in the process is sugarcane bagasse which is a by-product of sugar and ethanol production processes; the obtained energy is used in the form of mechanical power, electric power, and saturated steam in the processes. The surplus electricity can be sold. Technical, economical, and ecological analyses were performed for introduction of hydrogen production and BIG/GTCC in the sugarcane industry, using bagasse as fuel, in order to identify the better scenarios for electricity and heat generation. The introduction of these technologies will engender innovations in the sugarcane industry and will promote the sector development and as main results will increase electricity production with an economic and ecologic sustainable approach.