Evaluación económica y ambiental de la quema conjunta de carbón y bagazo en la industria colombiana de la caña de azúcar

Energy generation is key to any country’s development, and the threats to energy supply have led the Colombian government to establish national policies that stimulate energy generation projects. In response, this manuscript reports the economic impact and the GHG emission that have been simulated in this study to evaluate the co-firing of the coal-bagasse mixture in the cogeneration systems of the ethanol industry in the Cauca River Valley in Colombia as an opportunity to increase the economic benefits due to the increase of electricity sell to the national grid in the strong dry seasons. This study was carried out using the Virtual Sugarcane Biorefinery (VSB) modeling software employed for the simulation of agricultural and industrial parameters in integrated alternatives for the sugarcane industry, which was adjusted to the Colombian conditions to allow simulating the current electricity production in the sugarcane mills in the assessed region. The economic assessment of the co-firing process in the cogeneration system demonstrates that this industrial process represents an opportunity to increase the economic benefits by about 26%. However, the coal combustion in the boiler generates about 54% of the total GHG emissions for the consumption of coal, whereas the burning of bagasse corresponds to only 5%.La generación de energía es clave para el desarrollo de cualquier país, y las amenazas para el suministro de energía han llevado al gobierno colombiano a establecer políticas nacionales que estimulen los proyectos de generación de energía. En respuesta, este manuscrito informa sobre el impacto económico y la emisión de GEI que se han simulado en este estudio, para evaluar la quema conjunta de carbón y bagazo en los sistemas de cogeneración de la industria del etanol en el Valle del río Cauca, en Colombia, como una oportunidad para aumentar los beneficios económicos, debido al aumento en la venta de electricidad a la red nacional en las fuertes temporadas secas. Este estudio se realizó utilizando el software de modelado Biorrefinería Virtual de Caña de Azúcar (BVC), utilizado para la simulación de parámetros agrícolas e industriales en alternativas integradas para la industria de la caña de azúcar. La BVC, que se ajustó a las condiciones colombianas para permitir simular la producción actual de electricidad en los ingenios de caña de azúcar de la región estudiada. La evaluación económica del proceso de quema conjunta en el sistema de cogeneración demuestra que este proceso industrial representa una oportunidad para aumentar los beneficios económicos de alrededor del 26 %. Sin embargo, la combustión del carbón en la caldera genera aproximadamente el 54 % de las emisiones totales de GEI para el consumo de carbón, mientras que la quema de bagazo corresponde a solo el 5 %

SACCHARIFICATION OF SUGARCANE BAGASSE FOR ETHANOL PRODUCTION USLNG THE ORGANOSOLV PROCESS

Abstract THE SCOPE of this work is the reduction of the production cost of fuel ethanol, through hydrolysis of surplus bagasse from sugar mills with annexed distilleries. Ethanol could be obtained froin the sugar liquor af3er fernsentation and distillation. An Organosolv process using an ethanol-water mixture as solvent and diluted sulfuric acid (0.1-0.25%) as the reaction catalyst was developed. Reaction was done at 170-185°C and 20-25 kg/cm2. The work was done on a bench scale unit (20 kglh of raw bagasse). Processing for conversion to hexose and pentose sugars was in a short residence time reactor. Reaction products were totally dissolved in the organosolv solvent. Solvent was removed and sugar liquor recovered after removal of precipitated lignin. Results obtained in the pilot plant were: global conversion of bagasse in total reducing sugars was 59%, being sugar content in liquor 80 g/L, after 10-12 ininutes of residence time. The final liquor containing reducing sugars was fermented successfully to ethanol after blending with cane juice and molasses. Fernsei~tation used a yeast strain adapted to ferment the hexose fraction despite the high concentration of inhibitors present, such as short chain organic acid, furfural and hydroximetilfurfural. The ratio of hydrolysis liquor to cane sugar components was adjusted to match a maximum level of inhibitor in must. Results of the bench unit were scaled up to a 5000 litrestday pilot and demonstration unit (PDU). Our preliminary feasibility calculations allow us to forecast that the ethanol produced by the organosolv process should be competitive with current ethanol produced directly from cane juice and molasses. There is also a large potential for cost reduction once the hydrolysis reaction is optimised. Developme~st of fermentation of the pentose sugar fraction to ethanol, to be done in the future, will improve the economy of this process. The organosolv technology for bagasse hydrolysis is of medium complexity and Brazil or other developing countries can rapidly have access to it. This process could increase the production of alcohol in Brazil, using the same cane planted area and reducing the production costs, besides allowing the use of many other lignocellulose residues from agriculture, forest industry and others for ethanol production

Environmental and economic assessment of the co-firing of the coalbagasse mixture in the Colombian sugarcane mills

The energy generation is key to any country‘s development and the threats to energy supply have led the Colombian government to establish national policies that stimulate energy generation projects. In response, this manuscript reports the economic impact and the GHG emission that has been simulated in this study to evaluate the co-firing of the coal-bagasse mixture in the cogeneration systems of the ethanol industry in the Cauca River Valley in Colombia as an opportunity to increase the economic benefits due to the increase of electricity sell to the national grid in the strong dry seasons. This study was performed using the Virtual Sugarcane Biorefinery (VSB) modeling software used for the simulation of agricultural and industrial parameters in integrated alternatives for the sugarcane industry, which was adjusted to the Colombian conditions to allow simulating the current electricity production in the sugarcane mills in the assessed region. The economic assessment of the co-firing process in the cogeneration system demonstrates that this industrial process represents an opportunity to increase the economic benefits of about 26%. However, the coal combustion in the boiler generates about 54% of the total GHG emissions for the consumption of coal, whereas the burning of bagasse corresponds to only 5%.La generación de energía es clave para el desarrollo de cualquier país y las amenazas para el suministro de energía han llevado al gobierno colombiano a establecer políticas nacionales que estimulen los proyectos de generación de energía. En respuesta, este manuscrito informa sobre el impacto económico y la emisión de GEI que se ha simulado en este estudio para evaluar la quema conjunta de carbón y bagazo en los sistemas de cogeneración de la industria del etanol en el Valle del Río Cauca en Colombia como una oportunidad para aumentar los beneficios económicos debido al aumento en la venta de electricidad a la red nacional en las fuertes temporadas secas. Este estudio se realizó utilizando el software de modelado Biorrefineria Virtual de Caña de Azúcar (BVC) utilizado para la simulación de parámetros agrícolas e industriales en alternativas integradas para la industria de la caña de azúcar. La BVC que se ajustó a las condiciones colombianas para permitir simular la producción actual de electricidad en los ingenios de caña de azúcar de la región estudiada. La evaluación económica del proceso de quema conjunta en el sistema de cogeneración demuestra que este proceso industrial representa una oportunidad para aumentar los beneficios económicos de alrededor del 26%. Sin embargo, la combustión del carbón en la caldera genera aproximadamente el 54% de las emisiones totales de GEI para el consumo de carbón, mientras que la quema de bagazo corresponde a solo el 5%