Suchergebnisse

Ensiling sorghum with tropical forages has been shown to be a promising alternative for ruminant feed production, as this approach improves the quality of the sorghum silage. In this context, the goal of this study was to evaluate the fermentation characteristics and nutritive value of sweet sorghum silage made with different levels of Paiaguas palisadegrass and Ipypora grass. The experiment was conducted in a completely randomized 2 x 6 factorial design with four replications. Two forages (Paiaguas palisadegrass and Ipypora grass) were added to sorghum at six levels (0, 20, 40, 60, 80 and 100%), for a total of 48 experimental silos. After 50 days of fermentation, the silos were opened, and the fermentation profile and chemical composition of the silage were analysed. The results showed that the addition of Paiaguas palisadegrass and Ipypora grass to the sorghum silage increased the pH, buffering capacity and NH3-NT of the silage and reduced its dry matter content but did not affect its fermentation characteristics, which remained within an appropriate range. The addition of increasing levels of Paiaguas palisadegrass and Ipypora grass to the sorghum silage increased the crude protein and in vitro dry matter digestibility (IVDMD) of the silage and decreased the fibre fraction (neutral detergent fibre, acid detergent fibre and lignin) and ether extract contents. Adding tropical forages to sorghum silage material at levels above 40% is recommended. Among forage crops, addition of Paiaguas palisadegrass to sorghum silage resulted in higher content of crude protein and IVDMD. Mixed silages can be an effective alternative to improve the quality of forage sorghum silage.

Worldwide, there are various feedstocks such as straws, corn stover, sugarcane bagasse, sweet sorghum bagasse (SSB), grasses, leaves, whey permeate, household organic waste, and food waste (FW) that can be converted to valuable biofuels such as butanol. For the present studies, an economic analysis was performed to compare butanol production from three feedstocks (SSB ; FW ; and yellow top presscake, YTP or YT) using a standard process and an advanced integrated process design. The total plant capacity was set at 170,000&ndash ; 171,000 metric tons of total acetone butanol ethanol (ABE) per year (99,300 tons of just butanol per year). Butanol production from SSB typically requires pretreatment, separate hydrolysis, fermentation, and product recovery (SHFR). An advanced process was developed in which the last three steps were combined into a single unit operation for simultaneous saccharification, fermentation, and recovery (SSFR). For the SHFR and SSFR plants, the total capital investments were estimated as $213.72 × ; 106 and $198.16 × ; 106, respectively. It was further estimated that the minimum butanol selling price (using SSB as a feedstock) for the two processes were $1.14/kg and $1.05/kg. Therefore, SSFR lowered the production cost markedly compared to that of the base case. Butanol made using FW had an estimated minimum selling price of only $0.42/kg. This low selling price is because the FW to butanol process does not require pretreatment, hydrolysis, and cellulolytic enzymes. For this plant, the total capital investment was projected to be $107.26 × ; 106. The butanol selling price using YTP as a feedstock was at $0.73/kg and $0.79/kg with total capital investments for SSFR and SHFR of $122.58 × ; 106 and $132.21 × ; 106, respectively. In the Results and Discussion section, the availability of different feedstocks in various countries such as Brazil, the European Union, New Zealand, Denmark, and the United States are discussed. Additionally, the use of various microbial strains and product recovery technologies are also discussed.

Sorghum stands out among other plants recommended for ensiling due to its forage composition, its resistance to drought, and its planting range. New cultivars of grain and sweet sorghum that can be used for silage production are available, but there is little information regarding their ensiling characteristics. The aim of this study was to evaluate the fermentation characteristics at the ensiling of different purpose sorghum cultivars, at two crop periods. The trial was carried out at the Plant Production Department of the Federal Institute of Education, Science and Technology of Rondônia, Colorado do Oeste campus, Rondônia, Brazil, and chemical analyses were performed at the Laboratory of Animal Nutrition, at the Federal University of Mato Grosso, Cuiabá campus, Mato Grosso, Brazil. The experimental design used was a randomized block, in split-plot design, with four replicates. The plot treatments consisted of six sorghum cultivars grown for different purposes (grain sorghum: BRS 308 and BRS 310; forage sorghum: BR 655 and BRS 610; sweet sorghum: BRS 506 and CMSXS 647). Split-plot treatments consisted of two cropping seasons (first crop and second crop). The grain sorghum cultivar BRS 310 was the only one that had suitable dry matter content for ensiling; however, it was also the only one that did not show ideal water soluble carbohydrate content for ensiling. Nevertheless, all treatments presented pH below than 4.2 and ammonia nitrogen lower than 12% of total N, which indicates that the fermentation inside the silo had proceeded well. For sweet sorghum cultivars, higher ethanol and butyric acid content were observed for the first crop than for the second crop. All evaluated sorghum cultivars can be used for silage production, but the use of sweet sorghum is recommended at the second crop.

Abstract The application of high-potential thermotolerant yeasts is a key factor for successful ethanol production at high temperatures. Two hundred and thirty-four yeast isolates from Greater Mekong Subregion (GMS) countries, i.e., Thailand, The Lao People's Democratic Republic (Lao PDR) and Vietnam were obtained. Five thermotolerant yeasts, designated Saccharomyces cerevisiae KKU-VN8, KKU-VN20, and KKU-VN27, Pichia kudriavzevii KKU-TH33 and P. kudriavzevii KKU-TH43, demonstrated high temperature and ethanol tolerance levels up to 45 °C and 13% (v/v), respectively. All five strains produced higher ethanol concentrations and exhibited greater productivities and yields than the industrial strain S. cerevisiae TISTR5606 during high-temperature fermentation at 40 °C and 43 °C. S. cerevisiae KKU-VN8 demonstrated the best performance for ethanol production from glucose at 37 °C with an ethanol concentration of 72.69 g/L, a productivity of 1.59 g/L/h and a theoretical ethanol yield of 86.27%. The optimal conditions for ethanol production of S. cerevisiae KKU-VN8 from sweet sorghum juice (SSJ) at 40 °C were achieved using the Box-Behnken experimental design (BBD). The maximal ethanol concentration obtained during fermentation was 89.32 g/L, with a productivity of 2.48 g/L/h and a theoretical ethanol yield of 96.32%. Thus, the newly isolated thermotolerant S. cerevisiae KKU-VN8 exhibits a great potential for commercial-scale ethanol production in the future.

Not Available ; Solid state fermentation with pea pod waste and Aspergillus niger HN-1 resulted in filter paper cellu-lase (FP) and -glucosidase (BGL) activity of 30 FPU/gds and 270 U/gds, respectively. Validation withthe response surface optimized parameters (moisture content: 65%, pH 6.0, temperature: 33◦C, time:84 h) in a solid-state tray fermentation enhanced FP and BGL activity by about 40 and 28%, respectively.Multi-component enzyme from A. niger HN-1 produced FP, BGL, endoglucanase (EG), cellobiohy-drolase (CBHI), xylanase, -l-arabinofuranosidase, -xylosidase and xylan esterase with activities of41.07 ± 2.11 FPU/gds, 345.69 ± 17.1, 480.3 ± 21.5, 52.1 ± 1.5, 2800.5 ± 88.4, 88.1 ± 9.3, 280.8 ± 11.4 and3321.7 ± 14.8 U/gds, respectively. Enzyme was optimally active at temperature and pH of 55◦C and 5.0,respectively and demonstrated thermostability by retaining >95% activity for 6 h at 55◦C. SDS-PAGEshowed the presence of 11 protein bands with molecular mass ranging between 20 and 200 kDa, whilezymogram revealed the presence of multiple forms of EG, CBH and BGL with varying molecular mass.Hydrolysis of sweet sorghum bagasse at relatively high substrate loading (15%, w/v) with crude enzymeat 20 FPU/gds in thermostatically controlled glass reactor led to conversion of 82–91% of holocellulose tofermentable sugars in just 24 h as evident from HPLC analysis, showing promise for the reported enzymein bioprocessing applications. ; AMAAS sub-project (NBAIM/AMAAS/2008-09/AMBPH-05/HSO/BG/3/5982) from the Indian Council of Agricul-tural Research (ICAR), Government of India.

As a signatory to the Kyoto Protocol, the Philippines enacted the Biofuels Act of 2006 (RA 9367). Signed into law in January 2007, it aims for the phasing out of harmful gasoline additives and/or oxygenates, and the mandatory use of biofuels with one percent biodiesel blend and five percent bioethanol blend for all diesel and gasoline fuels, respectively. This policy has led to frenzied development of biofuel plantations, particularly sugarcane, cassava, and sweet sorghum for bioethanol production, and coconut, oil palm, and jatropha for production of biodiesel. Mindanao has been identified as a major contributor in fulfilling the Philippine government's biofuel targets. The island's vast agricultural lands are thus giving way to monocrop oil plantations.

The environment of a sugar factory is conducive to the propagation of microbes that are introduced with the harvested crop. Further introductions are made from the machinery surfaces and water during processing. Each microbe type has a preferred range of temperature and water activity, so a factory may have different populations in different areas. It is important to detect microbial presence so appropriate control measures can be taken, and to conserve expenses when treatment is not needed. The most ideal detection methods in a factory will yield accurate results quickly and inexpensively. A mannitol detection method has been developed for the sugarcane industry, and subsequently applied to sweet sorghum and sugar beet. Conversion of sugar crop byproducts, such as bagasse, are a potential new value stream. An analysis was conducted to determine whether environmental conditions and the presence of microbes in bagasse affects the chemical composition, and subsequent application for novel uses. Fuel value was found to be negatively affected when bagasse was left uncovered and exposed to sun and rain. The fuel characteristics were maintained. Bagasse was also successfully pelletized and converted to biochar for stable storage and transport.

Mención Internacional en el título de doctor ; Bioenergy is a key resource to addressing challenges such as climate change (anthropogenic CO₂ emissions), pollution (suspended particles), energy security and human well-being. Currently, most of the biomass produced worldwide is consumed for cooking and space heating which has raised concerns among governments and policy-makers, especially due to threats to human health. The present thesis focuses on studying the technical and economic feasibility of energy systems based on biomass. It is considered that the main problems regarding the deployment of biomass-based energy systems are: (a) use of traditional biomass; (b) selection of a biomass-based technology; (c) low diversification of the biomass portfolio. With regards to the use of traditional biomass, the thesis evaluates the impact of switching from a system dependent on traditional biomass to a centralized system using low-carbon technologies. The outcome is a model capable of estimating the net reduction of CO₂ emissions that could be obtained by displacing fuelwood and introducing modern biomass taking into account the CO₂ released not only in the production, collection, transport, pre-treatment and conversion of biomass but also the anthropogenic CO₂ emissions caused by shifting to alternative fuels to meet basic energy needs. Results show that even when households have to use alternatives fuels, burning biomass in combustion and gasification power plants still provide a significant reduction in CO₂ emissions. With regards to the selection of a biomass-based technology, this thesis includes a methodology to identify, evaluate and select the best suited technology for the conditions of a given biomass value chain. As any system is affected by the conditions where it is developed, biomass-based energy systems are strongly dependent on region/local conditions such as weather, type of biomass resources, among others. Thus, each region demands its own detailed study. Given the lack of studies related to bioenergy in developing regions such as Central America (CA), this thesis entails a full study case presentation for CA where 84% of the biomass produced is used for domestic cooking and heating. In this context, the thesis aims at improving the bioenergy assessment methodology by using a resource-focused approach to determine the key biomass resources in the region and a Multi-Actor Multi-Criteria Decision- Making method to identify a portfolio of thermochemical conversion technologies appropriate for CA, considering parameters that range from technical, economic, environmental to socio-political aspects. Furthermore, it includes a discussion about the barriers that have stopped the progress of biomass technologies and the challenges to achieve modern bioenergy systems in the region. Results reveal that the main source of biomass in CA is in the agricultural sector and the most appropriate technologies to transform CA's biomass are improved cooking stoves and biomass combustion power plants. With respect to the diversification of the biomass portfolio, currently, sugarcane bagasse is the biomass mostly used in large scale applications for the production of combined heat and power (CHP) in developing countries. Using a demand-driven assessment this thesis aims to evaluate the potential for electricity and ethanol production in CA using sweet sorghum as an alternative sugar crop. Three scenarios were built to analyse sweet sorghum production in terms of the land where it can be cultivated: cropland, sugarcane land in fallow and land in continuous production (intercropping system). The land under permanent crops was not considered for this evaluation. It is estimated that sweet sorghum could supply around 10% of region's electricity demand or supply the ethanol required to implement a 5% ethanol blending programme. Following this assessment, the thesis studies the integration of sweet sorghum into Central American sugar mills by using the existing machinery to process it. The short growing period of sweet sorghum would allow the CHP plants and distilleries to operate during off-season using sorghum bagasse and molasses as raw materials. This thesis provides a techno-economic analysis of the production of electricity and ethanol from sweet sorghum in a sugar mill. The data on various parameters used for techno-economic assessment were collected from an existing sugar mill and distillery in Central America. Results indicate that modern energy carriers from sweet sorghum can be produced at a competitive price under CA conditions and crucial variables determining the cost of electricity and ethanol are the installed capacity of the plant and crop yield. ; La bioenergía es fundamental para hacer frente a retos como el cambio climático (emisiones antropogénicas de CO₂), contaminación (partículas en suspensión), seguridad energética y bienestar humano. Actualmente, la mayor parte de la biomasa que se produce a nivel global se utiliza para fines domésticos (calefacción y cocina) lo cual ha generado preocupación entre los gobiernos y responsables de establecer políticas energéticas, especialmente por los potenciales daños a la salud. La presente tesis doctoral se enfoca en el estudio técnico y económico de sistemas energéticos basados en biomasa. Se considera que los principales problemas con respecto al uso de sistemas basados en biomasa son: (a) uso de biomasa tradicional; (b) selección de la tecnología adecuada; (c) baja diversificación del portafolio de recursos biomásicos. Con respecto al uso de biomasa tradicional, esta tesis evalúa el impacto de cambiar de un sistema altamente dependiente en biomasa tradicional a un sistema centralizado utilizando tecnologías con bajas emisiones de carbón. El resultado es una modelo capaz de estimar la reducción neta en las emisiones de CO₂ que se podrían obtener debido al desplazamiento de leña y el incremento en el uso de biomasa moderna. Dicho modelo no solamente toma en cuenta el CO₂ emitido por la producción, recolección, transporte, pre-tratamiento y conversión de la biomasa sino que también considera las emisiones antropogénicas de CO₂ debidas al uso de combustibles modernos para satisfacer las necesidades energéticas básicas de los usuarios de leña. Los resultados indican que aún cuando los consumidores de biomasa tradicional cambian a combustibles alternativos, la conversión de biomasa en plantas de potencia basadas en combustión y gasificación, proporcionan una reducción en emisiones de CO₂ significativa. Con respecto a la selección de una tecnología para transformar los recursos biomásicos, la presente tesis incluye una metodología para identificar, evaluar y seleccionar la tecnología más apropiada bajo las condiciones de un sistema energético dado. Al igual que cualquier sistema que es afectado por sus alrededores y la interacción de las partes que lo conforman, los sistemas energéticos basados en biomasa son fuertemente influidos por condiciones regionales/locales como el clima o los tipos de recursos biomásicos entre otros. Por lo tanto, cada región exige la realización de un estudio detallado que incluya la influencia de variables locales. En este sentido, teniendo en cuenta los pocos estudios técnicos relacionados al uso de bioenergía en regiones en desarrollo como por ejemplo Centroamérica (CA), esta tesis realiza un estudio detallado para CA donde el 84% de la biomasa producida es usada para satisfacer necesidades energéticas básicas. En este contexto, la tesis tiene como objeto proponer soluciones que permitan la explotación de biomasa de manera eficiente utilizando un enfoque basado en los recursos disponibles para determinar las fuentes de biomasa con mayor potencial en la región. A su vez se emplea un análisis multicriterio impulsado por la participación de varios actores para identificar un portafolio de tecnologías apropiadas basadas en procesos termoquímicos para su implementación en CA considerando aspectos que varían desde lo técnico, económico, medioambiental hasta lo socio-político. Así también, discute las barreras que han detenido el progreso en el uso de tecnologías basadas en biomasa y los retos que se tienen que afrontar para incrementar el uso de biomasa moderna en dicha región. Los resultados muestran que la principal fuente de biomasa en CA proviene del sector agrario y que la tecnología más apropiada para transformar dicho recurso son las cocinas mejoradas y las plantas de potencia basadas en combustión. Con respecto a la diversificación del portafolio biomásico, actualmente el bagazo de la caña de azúcar es la biomasa más utilizada para la producción de vapor y electricidad a gran escala en regiones en desarrollo como Latinoamérica. Utilizando un enfoque impulsado por la demanda de electricidad y etanol, esta tesis tiene como objeto evaluar el potencial del uso de sorgo dulce en CA para la producción de vectores energéticos sostenibles. Tres escenarios han sido planteados para estudiar el potencial del sorgo dulce en función de dónde esta planta podría ser cultivada: tierra para cultivos, tierras potencialmente baldías dedicadas al cultivo de caña de azúcar y un sistema de intercultivo de sorgo dulce con caña de azúcar. La tierra dedicada al uso continuo de cultivos ha sido excluida del presente estudio. Se estima que la utilización de sorgo dulce como cultivo energético podría proveer alrededor del 10% de la demanda energética de la región o proveer el etanol necesario para implementar un programa de etanol al 5% en la gasolina. Así mismo, la presente tesis estudia la integración del sorgo dulce a los ingenios azucareros de CA utilizando la misma maquinaria que se emplea en la caña de azúcar para procesar dicho cultivo energético. El corto periodo de crecimiento del sorgo dulce permitiría a las plantas de potencia y destilerías operar fuera de la temporada de caña de azúcar utilizado el bagazo y miel final del sorgo dulce como materia prima. La presente tesis proporciona un análisis tecno-económico de la producción de electricidad y etanol a partir de sorgo dulce en ingenio azucarero. Los datos necesarios como parámetros de entrada para el análisis tecno-económico fueron obtenidos de una planta existente de producción de azúcar y destilería en CA. Los resultados indican que la producción de vectores energéticos con tecnologías modernas puede ser llevada a cabo a precios competitivos bajo las condiciones de CA y las variables que lo determinan, ya sea el costo de la electricidad o etanol a partir del sorgo dulce, son la capacidad instalada de las plantas y el rendimiento del cultivo energético. ; This work started as part of a project supported by the Spanish Agency for International Development Cooperation (AECID). ; Programa Oficial de Doctorado en Ingeniería Mecánica y de Organización Industrial ; Presidente: Omar Raúl Masera Cerutti.- Secretario: Carolina Marugán Cruz.- Vocal: René M.J. Benders