Thesis (M.S.)--Mississippi State University. Department of Agricultural and Biological Engineering. / Title from title screen. Includes bibliographical references.

Thesis (Ph.D.)--Mississippi State University. Department of Political Science and Public Administration. / Title from title screen. Includes bibliographical references.

Submitted by Milena Rubi (milenarubi@ufscar.br) on 2017-08-09T12:48:03Z No. of bitstreams: 1 NAKASHIMA_Gabriela_2016.pdf: 18948386 bytes, checksum: c4adf2165784091a5371108a8c2bd529 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-08-09T12:48:12Z (GMT) No. of bitstreams: 1 NAKASHIMA_Gabriela_2016.pdf: 18948386 bytes, checksum: c4adf2165784091a5371108a8c2bd529 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-08-09T12:48:18Z (GMT) No. of bitstreams: 1 NAKASHIMA_Gabriela_2016.pdf: 18948386 bytes, checksum: c4adf2165784091a5371108a8c2bd529 (MD5) / Made available in DSpace on 2017-08-09T12:48:26Z (GMT). No. of bitstreams: 1 NAKASHIMA_Gabriela_2016.pdf: 18948386 bytes, checksum: c4adf2165784091a5371108a8c2bd529 (MD5) Previous issue date: 2016-04-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / In the sugarcane plantation it was common to use fire to facilitate the cutting and harvesting of sugarcane. However, Law 11,241 / 02 in São Paulo State provides the gradual elimination of this straw burning of sugarcane. The largest producer of sugarcane in Brazil is the São Paulo State, which has about 4.7 million hectares of planted area. It is estimated that one hectare produces about 14 tons of trash. Therefore, the mills have been trying to incorporate this trash in burning with the bagasse for power generation. However, high concentrations of mineral impurities are impossible its use for energy purposes. The aim of the study was to investigate the influence of storage time and particle size in the physicochemical characterization of the sugarcane trash. It was used the sugarcane trash inside and outside of the bale collected at different storage time (0, 1 and 2 years). The collected material was separated into four different particle sizes (> 0.420mm, 0.250-0.420mm, < 0.250mm and mix). The analyzes involved particle size distribution, proximate analysis, the high heating value (HHV), the chemical analysis of the components of the ashes, the images in the Scanning Electron Microscope (SEM), the Klason lignin content, the holocellulose content and extractives. There were variations in the results of the ash content with different particle sizes. It was observed a higher concentration of mineral impurities in smaller particles (< 0.250mm). The HHV varied from 15.9 to 18.3 MJ.kg-1 and showed no statistical difference for the treatments. The results indicate that the sugarcane trash presents problems related to mineral impurities which constrain its use as a solid fuel in the industry. The particle size interferes in their physicochemical characteristics. The trash can be stored in field and the time storage did not affect the quality for use as solid biofuel. / No manejo da cana-de-açúcar era comum a utilização do fogo para facilitar o corte e colheita da cana. No entanto, a Lei 11.241/02 do estado de São Paulo prevê a eliminação gradual da queima da palha da cana-de-açúcar. O maior produtor de cana-de-açúcar do Brasil é o estado de São Paulo, que possui aproximadamente 4,7 milhões de hectares de área plantada. É estimado que 1 hectare produza cerca de 14 toneladas de palha. Logo, as usinas vêm tentando incorporar esta palha na queima para geração de energia, juntamente com o bagaço. Porém, as altas concentrações de impurezas minerais estão impossibilitando seu uso para fins energéticos. O trabalho teve como objetivo o estudo da influência do tempo de estocagem e da granulometria na caracterização físico-química do palhiço da cana-de-açúcar. Foi utilizado o palhiço de canade-açúcar da superfície e do interior do fardo coletados em diferentes períodos de estocagem, 0, 1 e 2 anos. O material coletado foi separado em 4 granulometrias diferentes (> 0,420mm, 0,250-0,420mm, < 0,250mm e mix). As análises realizadas foram a distribuição granulométrica, a análise imediata, o poder calorífico superior (PCS), a análise química dos componentes das cinzas, as imagens no Microscópio Eletrônico de Varredura (MEV), o teor de lignina Klason, a holocelulose e os extrativos. Houve variações nos resultados do teor de cinzas com as diferentes granulometrias. Observou-se maior concentração de impurezas minerais nas partículas mais finas (< 0,250mm). O PCS variou entre 15,9 a 18,3 MJ.kg-1 e não apresentou diferença estatística para os tratamentos. Os resultados indicam que a palha de cana-de-açúcar apresenta problemas relacionados às impurezas minerais, que dificultam e restringem seu uso como combustível sólido na indústria. A granulometria da palha interferiu nas suas características físico-químicas. O palhiço pode ser estocado no campo e o tempo de estocagem não interferiu na qualidade para o uso como combustível sólido.

The study aims to evaluate the biomass production and nutrient content and silage quality of perennial ryegrass (Lolium perenne (L)), cocksfoot (Dactylis glomerata (L)) and tall fescue (Festuca arundinacea (Schreb)). Six varieties were used, two for each species. A completely randomized block designed replicated three times was conducted at University of Fort Hare Research Farm during 2014-2015 growing season. The plots were harvested at four-week interval (post emergency) for one year. Biomass yields were measured for fresh forage and dry matter yield. Duplicated samples were then dried, milled and analyzed for chemical and mineral composition (CP, NDF, ADF, and ash, Ca, P, K, Na, Mn, Cu, Zn and Fe) for only winter season. In addition the grasses were ensiled and the silage was analyzed for its fermentation parameters and nutrient content (lactic acid, pH, DM, CP, NDF, ADF, and ash, Ca, P, K, Na, Mn, Cu, Zn and Fe). Biomass results showed significant differences (P < 0.05) between season and varieties. On average Tall fescue varieties Jessup (13741.67 FM kg/ha), Alix (12007.78 FM kg/ ha) and Ryegrass varieties Samson (11597.22 FM kg/ha) and Nui (10591.67 FM kg/ha) had the highest fresh biomass yield. Similarly, Tall fescue varieties Jessup (2833.06 DM kg/ha) and Alix (2708.3 DM kg/ ha) and Ryegrass varieties Samson (2169.44 DM kg/ha) and Nui (2169.67 kg/ha) had the highest dry biomass yield. Throughout the year the average biomass yield was significantly different among species (P< 0.05). During summer and autumn Tall fescue varieties Jessup and Alix gave the highest dry matter yields of 3855.5 to 1977.8 DM kg/ha, and 3877.8 to 1900 DM kg/ha, respectively, and followed by Cocksfoot 2400 DM kg/ha. Ryegrass had the highest dry matter biomass yield in winter (2975 DM kg/ha) and the least in summer (977.75 DM kg/ha). There were no significant (P>0.05) differences on the chemical composition (CP, NDF, ADF, and ash) and mineral composition (Ca, P, K, Na, Mn, Cu, Zn and Fe) of the six varieties. The grass silage results showed significant differences (P< 0.05) among the six varieties for moisture content. Perennial ryegrass variety Nui (66.76 percent) had low moisture content than the other grass silages. The different varieties had no significant effects (P>0.05) on chemical composition (CP, NDF, ADF, and ash) and mineral composition (Ca, P, K, Na, Mn, Cu, Zn and Fe). It is concluded that the biomass production of the six varieties of three grass species was different throughout the year under irrigation hence Ryegrass and Tall fescue are recommended for dairy farmers in the region for all seasons. It can be concluded that there is no difference with respect to fermentation characteristics and nutrient content among the varieties of the grass species.

Rural development efforts to reduce poverty and enhance food security and generally improve livelihoods in developing countries continue to be constrained by high energy cost. For that reason, renewable energy has been identified as a possible panacea to fill this gap. Renewable energy is cheaper, more accessible and environmentally sustainable and promotes inclusivity. Biogas is a renewable energy that is readily available and easy to use by poor rural households. The use of biogas digesters among households in rural areas of developing countries is a well-known technology. The potential for biogas in these areas has been demonstrated and a strong economic case has been made. However, its adoption and use have been lower than expectations possibly as result of non-economic considerations, including social issues about which rural people hold different perceptions. Perceptions of rural households are important because they influence the behaviour to a large extent. Since limited access to affordable energy in rural areas has encouraged government and private organisations to initiate biogas projects to overcome the challenge, it is important to ascertain the factors that affect attitudes towards the technology. The present study sought to explore perceptions of rural households about biogas production towards rural household income in the Raymond Mhlaba Local Municipality. Specifically, this research investigated the state of biogas project being implemented by the University of Fort Hare’s Institute of Technology (FHIT), the perceptions of respondents towards biogas production and determine the contribution of biogas consumption to rural income. The study also aimed to identify the factors affecting the adoption of biogas production in the study area. The study was carried out in Melani village in Raymond Mhlaba Local Municipality in the Eastern Cape Province of South Africa and employed survey data obtained from 48 households who were enumerated to identify their perceptions on biogas production, with special emphasis on the role and effect contributed to rural income of Melani village. The study employed a cross-sectional research design and purposive sampling technique was used in data collection. Data were collected and captured in Excel and then analysed using the statistical package for social sciences (SPSS) Version 24 Descriptive statistics was used to examine socio-economic characteristics of households and state of biogas production in the area, Bivariate correlation analysis was used to determine the relationships among the key elements of perceptions of household towards biogas adoption, binary logistic model was used to estimate factors influencing adoption of biogas technology by households. The results show that women were dominant for both adopters and non-adopters of biogas. The majority of households were young with mean age of 40 years while for non-adopters were 65 years old on average. The results showed high levels of literacy amongst household adopters. Majority of the households for both adopters and non-adopters of biogas technology were married and unemployed and household size ranged from one to five persons, with social grants being dominant source of income. The bivariate correlation analysis suggests a positive effect of green pepper production and livestock ownership on biogas technology adoption. Age and level of education were negatively correlated with adoption of biogas. The cross tabulation analysis suggests that water scarcity, lack of knowledge about biogas technology, cattle ownership, lack of maintenance and repairing, flooded biogas digesters during rainy season are negatively associated with the uptake of biogas technology. The empirical results from binary logistic model suggest that land size was the key determinant of adoption behaviour towards biogas technology while age of the household head, source of income and level of education may have a negative influence on adoption of biogas technology. Based on the findings highlighted above, the study recommends strategies to encourage households to adopt biogas technology.

Orientador: Osmar de Carvalho Bueno / Coorientador: José Giacomo Baccarin / Coorientador: Gregório Antolín Giraldo / Banca: Wilson Kendy Tachibana / Banca: David Pereira Lopes Santos / Banca: Gregorio Antoniolin Giraldo / Resumo: Essa pesquisa investigou o tema de energias renováveis por meio de um método proposto com a finalidade de rastrear a viabilidade econômico-financeira em duas plantas industriais a partir de biomassa. A primeira, denominada "planta industrial unidade sucroenergética" (também nomeada neste trabalho como planta I), situada no Estado de São Paulo, Brasil, produz não somente açúcar e álcool, mas também energias (mecânica, térmica e elétrica), sendo estas a partir do bagaço da cana-de-açúcar. Já a segunda, denominada "planta industrial central térmica" (também chamada neste estudo de planta II), localizada na Comunidade Autônoma de Castilla y León (uma das Comunidades Autônomas que pertence à região norte da Espanha), produz somente energia térmica, representada neste estudo por MWh de energia elétrica. Essa planta II produz energias a partir de resíduos florestais provenientes de podas de árvores (pinheiros). Ambas as plantas pertencem ao Setor de Energias Renováveis a partir da Biomassa. O método proposto de análise, denominado "Proposta de Gestão Econômico-Financeira Aplicada em Energias Renováveis a partir da Biomassa, partiu dos Postulados Teóricos de Kaplan e Anderson (2008; 2007; 2004), de Kaplan e Cooper (1988), de Gitman (2004); Van Horne (1993) e de Allora et al (1995). Os resultados apresentados foram de grande relevância ao setor, como as informações geradas pelo projeto modelo-piloto-I, que atribuiu 24,81% dos custos operacionais ao produto energia elétrica e 75,19% aos produtos álcool e açúcar. A capacidade não-utilizada dessa planta apresentou-se na ordem de 7.097.752 minutos, equivalente a 24,57% do total da capacidade ... / Abstract: This research investigated the topic of renewable energy through a proposed method in order to trace the economic and financial viability of two industrial plants from biomass. The first, called 'sugarcane unit industrial plant' (also named as plant I in this text), located in São Paulo State, Brazil, produces not only sugar and alcohol, but also energy (mechanical, thermal and electrical), and these types of energy are produced from sugarcane bagasse. The second, called 'industrial thermal power plant' (also named as plant II), located in Castilla y León (one of the Autonomous Communities in Northern Spain), produces only thermal energy, indicated by MWh. Plant I produces energy out of forest residues from pruning pine trees. Both plants belong to Biomass Renewable Energy. The proposed method of analysis entitled as 'Proposal of Applied Economic and Financial Management in Biomass Renewable Energy' is based on Kaplan's and Anderson's (2008, 2007, 2004), Kaplan's and Cooper's (1988), Gitman's (2004); Van Horne's (1993) and Allora's et al (1995) theoretical postulates. The ... / Doutor

Submitted by Milena Rubi ( ri.bso@ufscar.br) on 2017-10-24T11:28:32Z No. of bitstreams: 1 HANSTED_Ana_Larissa_2017.pdf: 1877023 bytes, checksum: c3a1a7b3f4c03cc2997fbd0cfcc7e536 (MD5) / Approved for entry into archive by Milena Rubi ( ri.bso@ufscar.br) on 2017-10-24T11:28:43Z (GMT) No. of bitstreams: 1 HANSTED_Ana_Larissa_2017.pdf: 1877023 bytes, checksum: c3a1a7b3f4c03cc2997fbd0cfcc7e536 (MD5) / Approved for entry into archive by Milena Rubi ( ri.bso@ufscar.br) on 2017-10-24T11:28:50Z (GMT) No. of bitstreams: 1 HANSTED_Ana_Larissa_2017.pdf: 1877023 bytes, checksum: c3a1a7b3f4c03cc2997fbd0cfcc7e536 (MD5) / Made available in DSpace on 2017-10-24T11:29:00Z (GMT). No. of bitstreams: 1 HANSTED_Ana_Larissa_2017.pdf: 1877023 bytes, checksum: c3a1a7b3f4c03cc2997fbd0cfcc7e536 (MD5) Previous issue date: 2017-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The bark is a residue that can be used as fuel by industry. One of the problems of the use is the contamination. The purpose of this paper was the physico-chemical characterization of eucalyptus bark used as a fuel in a wood panel industry, relating the high heating value (HHV) with the ash content. Six treatments were provided according to the particle size: T1 (850µm to 425 µm / unwashed), T2 (250 µm / unwashed), T 3 (<150 µm / unwashed), T4 (850µm to 425 µm / washed), T5 (250 µm / washed), T6 (<150 µm / washed). The material was assessed regarding moisture content. The treatments were subjected to HHV and proximate analysis. The ashes were analyzed under SEM - EDS in order to identify the components/contaminants. The data obtained in this study were statistically analyzed using the software R. The material presented moisture content of 70% on a dry basis, which is considered high for use in bioenergy. Contaminants comp onents such as calcium and silica were identified in the ash material. The proximate analysis showed a significant difference among treatments, the ash content presented values from 2.63% (T1) to 13.86% (T3). The process of washing the bark was efficient f or the reduction in ash content only in the particle size <150 µm. The separation in particle size extracts of the bark presented a good technique to reduce the contaminants. / A casca de eucalipto é um resíduo que pode ser usado como combustível pela indústria. Um dos problemas da utilização deste resíduo é a contaminação. O objetivo deste trabalho foi a caracterização físico - química da casca do eucalipto utilizada como combustível em uma indústria de painéis de madeira reconstituída. Para diminuir os contaminantes, foi feita uma lavagem da casca em água corrente. Foram realizados seis tratamentos de acordo com o tamanho de partícula e processo de lavagem: T1 (850µm a 425µm / não lavado), T2 (250µm / não lavado), T3 (<150µm / não lavado), T4 (850µm a 425µm / lavado), T5 (250µm / lavada), T6 (<150µm / lavada). O material foi avaliado quanto ao teor de umidade no momento da coleta. Os tratamentos foram submetidos a análise química imediata e determinado o poder calorífico superior (PCS). As cinzas foram analisadas em MEV - EDS, a fim de identificar os componentes/contaminantes. Os dados obtidos neste estudo foram analisados estatisticamente utilizando o software R. O material apresentou teor de umidade de 70% em base seca, o que é considerado elevado para utilização na bioenergia. Componentes contaminantes, tais como o cálcio e sílica foram identificados nas cinzas do material. A análise química imediata mostrou uma diferença significativa entre os tratamentos, o teor de cinzas apresentou valores de 2,63% (T1) a 13,86% (T3). O processo de lavagem da casca foi eficiente para a redução do teor de cinzas apenas no tamanho de partícula <150µm. A separação da casca em diferentes tamanhos de partículas forneceu resultados satisfatórios para redução dos contaminantes.

Capes; Fundação Araucária / Este estudo consiste na avaliação do desempenho simulado de um sistema conjunto gaseificador-motor, como alternativa para a produção de potência mecânica e/ou eletricidade a partir do uso de combustíveis fósseis e renováveis. Para tal, escolheu-se um gaseificador de leito fluidizado circulante, operando com dois tipos de biomassa lignocelulósica característicos da região Sul do Brasil, além de carvão mineral e resíduos domésticos. O modelo de gaseificação selecionado baseou-se no método não-estequiométrico da minimização da energia livre de Gibbs, com modificações referentes a correlações semi-empíricas encontradas na literatura, para correção da composição encontrada de carbono não-convertido e metano na fase de pirólise. Com esse modelo, aplicado na faixa de razão de equivalência de 0,22 a 0,54, pôde-se obter a composição do gás combustível produzido no reator, bem como algumas das suas propriedades, como densidade e poder calorífico. Essas propriedades obtidas para o gás combustível puderam ser utilizadas na simulação da operação de um motor de ignição por centelha marca FIAT, com cilindrada de 2,0 L e cinco cilindros. Para o motor, optou-se por um modelo zero-dimensional não-adiabático de liberação finita de calor, de forma a avaliar seu desempenho em relação a potência, torque e consumo específico. Em posse desses parâmetros, também foi possível avaliar o rendimento global do sistema gaseificador-motor escolhido para cada tipo de combustível utilizado. A validação por comparação dos resultados obtidos a partir dos modelos adotados, quando realizada por separado no gaseificador e no motor de combustão interna, mostra que os dados experimentais da literatura se ajustam relativamente bem. A quantidade total de gás produzida pelo gaseificador abriu a possibilidade da operação simultânea com vários motores, obtendo-se uma potência máxima total ao freio de 103,3 kW para casca de arroz com o uso de 6 motores, 207,7 kW para serragem de pinus com o uso de 9 motores, 194,3 kW para carvão mineral com o uso de 8 motores, e 343,6 kW para lixo doméstico com o uso de 20 motores, sempre com os motores operando em paralelo. As curvas de torque e de consumo específico por motor seguiram a tendência esperada, obtendo-se o maior torque com o uso de carvão mineral e o menor consumo específico também com carvão. Dessa forma, obteve-se uma eficiência global máxima do sistema de potência de 14,0% para casca de arroz, 18,6% para serragem de pinus, 21,0% para carvão mineral, e 28,2% para lixo doméstico, resultados que se encontram dentro da faixa reportada em trabalhos prévios. / In this study, the simulated performance of a combined gasifier-engine system operated with fossil and renewable fuels was carried out. A circulating fluidized bed gasifier fed with two kinds of very common lignocellulosic biomass available at Southern Brazil, as well as with coal and municipal solid waste were chosen to produce the fuel gas. The gasification model was based on the non-stoichiometric method of Gibbs free energy minimization, including modifications regarding semi-empirical correlations found in literature, in order to correct the gas yield calculated for non-converted carbon and methane from pyrolysis. By applying this model with equivalence ratio varying from 0.2 to 0.54, it was possible to obtain the composition of the fuel gas, as well as some of its properties, such as density and heating value. These properties were used to simulate the operation of a 2.0 L, 5-cylinder spark-ignited FIAT engine. For this engine, a zero-dimensional, non-adiabatic, finite heat release model was chosen in order to assess its performance regarding power, torque and specific fuel consumption. From these results, it was possible to evaluate the overall performance of the gasifier-engine power system for each kind of solid fuel used. The validation by comparison of the data obtained from the gasification model, as well as from the engine model, has shown good agreement with those available in previous works. The producer gas yield was always higher than the amount of gas consumed by a single engine, making it possible to obtain maximum brake power of 103.6 kW for rice husk with 6 engines, 207.7 kW for pine sawdust with 9 engines, 194.3 kW for coal with 8 engines, and 343,6 kW for municipal solid waste with 20 engines, always in parallel setup. The consumption and torque curves have shown the expected behaviour, with both best results being obtained for coal. Therefore, the maximum overall performance of the power system was 14.0% for rice husk, 18.6% for pine sawdust, 21.0% for coal, and 28.2% for municipal solid waste, which was in agreement with results from previous studies.

CAPES / Neste trabalho é descrito um sensor de índice de refração baseado em redes de Bragg em fibra multimodo para o setor de combustíveis líquidos. A utilização dos dispositivos propostos visa superar as desvantagens associadas com a monitoração de amostras de índice de refração elevados. A sensibilidade do transdutor pode ser adaptada, ajustando o diâmetro final da fibra na qual a rede de Bragg é gravada. Devido à relação entre a razão sinal-ruído e a sensibilidade, os parâmetros do sensor devem ser otimizados para obter uma faixa dinâmica de índice de refração adequada para aplicações específicas. A características metrológicas do sensor são determinadas, resultando em resoluções entre 5,6% v/v e 0,4% v/v para os índices de refração variando entre 1,4562 e 1,4729. Os resultados mostram o potencial do dispositivo em aplicações específicas relativas à avaliação da qualidade do biodiesel e análise de conformidade de misturas diesel-biodiesel. / In this work, a multimode fiber Bragg refractive sensor for the liquid fuel sector is described. The use of etched devices is proposed to overcome the drawbacks associated with sensing high refractive index samples employing fiber transducers. The transducer sensitivity can be tailored by adjusting the final diameter of the etched Bragg grating. Due to a trade between the signal-to-noise ratio and the sensitivity, operational parameters of the sensor must be designed to match the expected refractive index dynamic range for specific applications. Metrological properties of the sensor are determined, resulting in resolution from 5.6% v/v to 0.4% v/v for refractive indexes ranging from 1.4562 to 1.4729. Specific applications regarding the quality assessment of biodiesel and conformity analysis of diesel- biodiesel blends are discussed.

Capes; Fundação Araucária / Este estudo consiste na avaliação do desempenho simulado de um sistema conjunto gaseificador-motor, como alternativa para a produção de potência mecânica e/ou eletricidade a partir do uso de combustíveis fósseis e renováveis. Para tal, escolheu-se um gaseificador de leito fluidizado circulante, operando com dois tipos de biomassa lignocelulósica característicos da região Sul do Brasil, além de carvão mineral e resíduos domésticos. O modelo de gaseificação selecionado baseou-se no método não-estequiométrico da minimização da energia livre de Gibbs, com modificações referentes a correlações semi-empíricas encontradas na literatura, para correção da composição encontrada de carbono não-convertido e metano na fase de pirólise. Com esse modelo, aplicado na faixa de razão de equivalência de 0,22 a 0,54, pôde-se obter a composição do gás combustível produzido no reator, bem como algumas das suas propriedades, como densidade e poder calorífico. Essas propriedades obtidas para o gás combustível puderam ser utilizadas na simulação da operação de um motor de ignição por centelha marca FIAT, com cilindrada de 2,0 L e cinco cilindros. Para o motor, optou-se por um modelo zero-dimensional não-adiabático de liberação finita de calor, de forma a avaliar seu desempenho em relação a potência, torque e consumo específico. Em posse desses parâmetros, também foi possível avaliar o rendimento global do sistema gaseificador-motor escolhido para cada tipo de combustível utilizado. A validação por comparação dos resultados obtidos a partir dos modelos adotados, quando realizada por separado no gaseificador e no motor de combustão interna, mostra que os dados experimentais da literatura se ajustam relativamente bem. A quantidade total de gás produzida pelo gaseificador abriu a possibilidade da operação simultânea com vários motores, obtendo-se uma potência máxima total ao freio de 103,3 kW para casca de arroz com o uso de 6 motores, 207,7 kW para serragem de pinus com o uso de 9 motores, 194,3 kW para carvão mineral com o uso de 8 motores, e 343,6 kW para lixo doméstico com o uso de 20 motores, sempre com os motores operando em paralelo. As curvas de torque e de consumo específico por motor seguiram a tendência esperada, obtendo-se o maior torque com o uso de carvão mineral e o menor consumo específico também com carvão. Dessa forma, obteve-se uma eficiência global máxima do sistema de potência de 14,0% para casca de arroz, 18,6% para serragem de pinus, 21,0% para carvão mineral, e 28,2% para lixo doméstico, resultados que se encontram dentro da faixa reportada em trabalhos prévios. / In this study, the simulated performance of a combined gasifier-engine system operated with fossil and renewable fuels was carried out. A circulating fluidized bed gasifier fed with two kinds of very common lignocellulosic biomass available at Southern Brazil, as well as with coal and municipal solid waste were chosen to produce the fuel gas. The gasification model was based on the non-stoichiometric method of Gibbs free energy minimization, including modifications regarding semi-empirical correlations found in literature, in order to correct the gas yield calculated for non-converted carbon and methane from pyrolysis. By applying this model with equivalence ratio varying from 0.2 to 0.54, it was possible to obtain the composition of the fuel gas, as well as some of its properties, such as density and heating value. These properties were used to simulate the operation of a 2.0 L, 5-cylinder spark-ignited FIAT engine. For this engine, a zero-dimensional, non-adiabatic, finite heat release model was chosen in order to assess its performance regarding power, torque and specific fuel consumption. From these results, it was possible to evaluate the overall performance of the gasifier-engine power system for each kind of solid fuel used. The validation by comparison of the data obtained from the gasification model, as well as from the engine model, has shown good agreement with those available in previous works. The producer gas yield was always higher than the amount of gas consumed by a single engine, making it possible to obtain maximum brake power of 103.6 kW for rice husk with 6 engines, 207.7 kW for pine sawdust with 9 engines, 194.3 kW for coal with 8 engines, and 343,6 kW for municipal solid waste with 20 engines, always in parallel setup. The consumption and torque curves have shown the expected behaviour, with both best results being obtained for coal. Therefore, the maximum overall performance of the power system was 14.0% for rice husk, 18.6% for pine sawdust, 21.0% for coal, and 28.2% for municipal solid waste, which was in agreement with results from previous studies.