16 research outputs found
Eliminación De Refrigerantes Agotadores De La Capa De Ozono Por Incineración
Existe la necesidad de encontrar métodos alternativos fácilmente replicables para disponer de las sustancias agotadoras de la capa de ozono. En respuesta a esta necesidad este trabajo propone la incineración como método de disposición final de estas sustancias. Inicialmente se establece analíticamente la sustancia reductora más apropiada. Se concluye que la utilización de hidrógeno para la incineración es la más adecuada ya que asegura una alta eficiencia de destrucción. Adicionalmente se determinan las condiciones óptimas de operación (presión, temperatura y relación de flujos). Posteriormente se diseña y construye un incinerador tipo laboratorio con el objeto de verificar experimentalmente las conclusiones obtenidas analíticamente. La composición de los subproductos de combustión se determinó por cromatografía de gases con espectrometría de masas. Los resultados preliminares muestran que la disposición de los refrigerantes agotadores de la capa de ozono es técnicamente factible mediante incineración con hidrógeno. Se continúa trabajando en alternativas para disminuir los costos del proceso
Performance and emissions of a heavy duty diesel engine fuelled with palm oil biodiesel and premium diesel
Biodiesels are promoted as alternative fuels due their potential to reduce dependency on fossil fuels and carbon emissions.Research has been addressed in order to study the emissions of light duty vehicles. However, the particle matter and gaseous emissions emitted from heavy-duty diesel engines fueled with palm-biodiesel and premium diesel fuel have seldom been addressed. The objective of this study was to explore the performance and emission levels of a Cummins 4-stroke, 9.5 liter, 6-cylinder diesel engine with common rail fuel injection, and a cooled exhaust gas recirculation (EGR). The palm-biodiesel lowered maximum engine output by much as 10 %. The engine emissions data is compared to standards from 2004, and is determined to pass all standards for diesel fuel, but does not meet emissions standards for PM or NOx for palm-biodiesel
Bioenergy technology roadmap for Colombia
The importance of using bioenergy for reducing oil dependence and greenhouse gas (GHG) emissions, diversifying the energy portfolio and supporting rural development is been increasingly recognized in Colombia. Against this background, this roadmap provides a long-term vision and goals to sustainably deploy biofuel and biomass technologies in Colombia until 2030. The roadmap identifies barriers to bioenergy deployment and suggests specific actions that should be taken by stakeholders to accomplish the proposed goals. It adopts a methodology from the International Energy Agency for developing technology roadmaps and combines detailed energy modeling with experienced advice from over 30 bioenergy experts from the government, academia, industry and non-governmental organizations.Based on expert feedback, the roadmap defines two visions, which are translated into two scenarios for detailed evaluation:The first vision, which is analyzed in Scenario I, focuses on new technologies and targets their deployment for the production of biomethane, biomass-based power generation and combined-heat-and-power (CHP). It fixes the current mandate for blending first generation liquid biofuels.
The second vision, which is analyzed in Scenario II, combines new and traditional technologies and targets a combination of new technologies for the production of biomethane, electricity and CHP with further growth of first generation biofuels.
A detailed set of goals, milestones, technologies, policies and barriers are defined for each of the two visions. Long-term goals in the bioenergy area include:
Biodiesel: increase the quota mandate to B20 in 2020 and B30 in 2030.
Bioethanol: a) increase the quota mandate to E20 in 2025 and b) implement an E85 fuel program in 2030.
Renewable diesel: achieve a 10% contribution (on an energy basis) of renewable diesel to the total diesel fuel production in 2030.
Biomethane: use 5% of biomass residues and animal waste resources nationwide to produce biomethane to be injected into the natural gas network by 2030.
Power generation and CHP: a) achieve a renewable power target of 10% by 2025, b) use 5% of the biogas from animal waste and municipal water treatment plants nationwide by 2030, c) use 100% of the biogas produced in the water treatment process of biodiesel production plants by 2030, d) use 10% of the municipal landfill gas produced nationwide by 2030.
A detailed energy system model for Colombia is set up and used to evaluate impacts on energy demand, supply, infrastructure and GHG emissions for Scenarios I and II and a baseline scenario that assumes no change in policies or deployment of new technologies. A land use and trade model that is linked to the energy system model is used to estimate land requirements for accomplishing the roadmap targets. A subset of Scenario II (Scenario II with expansion) considers a significant expansion in the cultivation of land beyond the Valley of the Cauca River.Results for the baseline show significant reductions in the share of bioenergy in the primary energy demand and various sectors. In contrast, Scenarios I and II are characterized by an increased share of bioenergy. In both scenarios, the bioenergy share for power generation and natural gas supply grows to about 6% in 2030. However, the share of bioenergy in the primary energy demand still declines to about 10% in 2030.Relative to the baseline, in Scenario I, bioenergy-induced emissions reduction amounts to about 11 mio tons of CO2-eq. and savings in fossil fuels of 2 mio tons of oil equivalent (TOE). The share of bioenergy in road transport remains unchanged. In Scenario I, an increase in land for producing liquid biofuels and woodfuel to 0.67 mio ha by 2030 is expected. Scenario I can accomplish long-term emission targets with available land and turns out to be the most effective scenario in terms of emission reduction per additional hectare of land. In Scenario II bioenergy-induced emissions reduction relative to the baseline amounts to about 20 mio tons of CO2-eq. and savings in fossil fuels of about 4.5 mio TOE (Scenario II with expansion: 22 mio tons of CO2-eq. and 5.4 mio TOE). The share of bioenergy in road transport grows to 24%. An increase in land for producing liquid biofuels and woodfuel to 1.1 mio ha by 2030 is expected in Scenario II (Scenario II with expansion: 1.3 mio ha). However, emissions reductions per additional hectare of land are about four to five times less compared to Scenario I. The roadmap shows that the most effective policy measures to reduce greenhouse gas emissions would address power generation and CHP applications, which account for more than 50% in emission reductions. The bulk of these reductions in emissions come from avoiding methane release via landfill gas and biogas from animal waste through combustion in reciprocating engines, followed by CO2 emission reduction in biomass-based power generation, and policies on first generation biofuels (i.e. bioethanol, biodiesel and renewable diesel).</p
Proyección de costos de un bus articulado con motor dedicado a gas natural para ser utilizado en los sistemas de transporte masivo de colombia
El objetivo del presente trabajo es mostrar los resultados del estudio comparativo de costos entre dos buses articulados que operan con diferentes combustibles, gas natural comprimido y diesel. Los resultados se utilizarán para establecer la viabilidad económica de la implementación de flotas de este tipo de buses en los sistemas de transporte masivo de las grandes ciudades colombianas. La proyección se realizó siguiendo las recomendaciones de operación y mantenimiento dadas por los fabricantes de los buses. Posteriormente se consideran tres costos importantes: motor e indispensables, combustible y mantenimiento preventivo. Para este estudio se supone la vida útil de los buses como de 10 años, y se plantean dos escenarios diferentes para la evolución de los precios del combustible. Los resultados muestran que los costos de operación y mantenimiento tienen un comportamiento similar entre ambas tecnologías, aún cuando los costos asociados al mantenimiento preventivo son menores para el bus alimentado con gas natural, en contraste con el análisis de los costos de motor e indispensables.Sin embargo es importante anotar que la mayor influencia sobre los costos de operación y mantenimiento recae en el comportamiento del precio de los combustibles. El artículo describe la naturaleza y estructura de los diferentes costos implementados en el estudio y la contribución de cada uno en el análisis económico, obteniendo así los costos de operación y mantenimiento para las dos tecnologías
Plant diversity patterns in neotropical dry forests and their conservation implications
This is the author accepted manuscript. The final version is available from American Association for the Advancement of Science via the DOI in this record.Seasonally dry tropical forests are distributed across Latin America and the Caribbean and are highly threatened, with less than 10% of their original extent remaining in many countries. Using 835 inventories covering 4660 species of woody plants, we show marked floristic turnover among inventories and regions, which may be higher than in other neotropical biomes, such as savanna. Such high floristic turnover indicates that numerous conservation areas across many countries will be needed to protect the full diversity of tropical dry forests. Our results provide a scientific framework within which national decision-makers can contextualize the floristic significance of their dry forest at a regional and continental scale.This paper is the result of the Latin American and Caribbean Seasonally Dry Tropical Forest Floristic Network (DRYFLOR), which has been supported at the Royal Botanic Garden Edinburgh by a Leverhulme Trust International Network Grant (IN-074). This work was also supported by the U.K. Natural Environment Research Council grant NE/I028122/1; Colciencias Ph.D. scholarship 529; Synthesys Programme GBTAF-2824; the NSF (NSF 1118340 and 1118369); the Instituto Humboldt (IAvH)–Red colombiana de investigación y monitoreo en bosque seco; the Inter-American Institute for Global Change Research (IAI; Tropi-Dry, CRN2-021, funded by NSF GEO 0452325); Universidad Nacional de Rosario (UNR); and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). The data reported in this paper are available at www.dryflor.info. R.T.P. conceived the study. M.P., A.O.-F., K.B.-R., R.T.P., and J.W. designed the DRYFLOR database system. K.B.-R. and K.G.D. carried out most analyses. K.B.-R. R.T.P., and K.G.D. wrote the manuscript with substantial input from A.D.-S., R.L.-P., A.O.-F., D.P., C.Q., and R.R. All the authors contributed data, discussed further analyses, and commented on various versions of the manuscript. K.B.-R. thanks G. Galeano who introduced her to dry forest research. We thank J. L. Marcelo, I. Huamantupa, C. Reynel, S. Palacios, and A. Daza for help with fieldwork and data entry in Peru
Particle matter from a diesel engine fueled with jatropha curcas oil biodiesel and ultra low sulphur diesel
Biodiesels are promoted as alternative fuels due to their potential to reduce dependency on fossil fuels
and carbon emissions. Research in this field has focused on the study of the emissions of light duty
vehicles. However, particle matter and gaseous emissions emitted from heavy-duty diesel engines fueled
by Jatropha Oil Biodiesel (JOB) and Ultra-Low Sulphur Diesel (ULSD) has not been studied. The objective of
this study is to explore the performance and emission levels of a Cummins 4-stroke, 4.8 liter, 4-cylinder diesel
engine with common rail fuel injection, equipped with a cooled Exhaust Gas Recirculation (EGR). There was
a substantial reduction by the use of JOB in unburned hydrocarbons (- 45%), carbon monoxide (- 75%), and
particulate matter (- 25%) compared to emission from diesel fuel. At mid and high loads, NOx emissions
were higher for JOB compared to ULSD. Most of the particles (64%) for ULSD were in a range of between
40 and 560 nm. On the other hand, most of the particles (94%) for JCB mode were between 6 and 40 nm.
In the range between 6 and 40 nm, mass mean diameters in ULSD were 34.4, 34.7 and 33.3 nm while for
JOB they were 21.3, 18.2 and 20.1 nm for 100, 50 for a 10% load, respectively.Obiodiesel tem se promovido como um combustível alternativo para reduzir a dependência dos
combustíveis fósseis e emissões de carbono. A pesquisa neste campo tem se enfocado no estudo
de emissões de veículos de baixa capacidade. Entretanto, não se estudou as emissões de veículos
de trabalho pesado operados com Biodiesel de Óleo de Jatropha (BAJ) e Diesel de Baixo Conteúdo de
Enxofre (DBCA). O objetivo deste estudo foi explorar o desempenho e os níveis de emissão de um motor
Cummins de 4 tempos, 4.8 litros, 4 cilindros, em ciclo diesel, com um sistema de injeção de trilho comum,
dotado de um inter-resfriador com válvula de recirculação de gases (VRG). Observou-se redução substancial
com o uso de BAJ nos hidrocarbonetos sem queimar (-45%), no monóxido de carbono (-75%), e o material
particulado (-25%). Muitas partículas (64%) para DBCA estiveram na categoria entre 40 e 560 nm. Por
outro lado, muitas das partículas (94%) para BAJ estiveram entre 6 e 40 nm. Na categoria entre 6 e 40 nm,
o diâmetro médio mássico para DBCA foram 34.4, 34.7 e 33.3 nm, enquanto que para BAJ foram 21.3,
18.2 e 20.1 nm para 100, 50 e 10% de carga, respectivamente.El biodiesel se ha promocionado como un combustible alternativo para reducir la dependencia de
los combustibles fósiles y emisiones de carbono. La investigación en este campo se ha enfocado
en el estudio de emisiones de vehículos de baja capacidad. Sin embargo, no se han estudiado las
emisiones de vehículos de trabajo pesado operados con Biodiesel de Aceite de Jatropa (BAJ) y Diesel de Bajo
Contenido de Azufre (DBCA). El objetivo de este estudio fue explorar el desempeño y los niveles de emisión
de un motor Cummins de 4 tiempos, 4.8 litros, 4 cilindros, en ciclo diesel, con un sistema de inyección de
riel común, dotado de un inter-enfriador con válvula de recirculación de gases (VRG). Se observó reducción
sustancial con el uso de BAJ en los hidrocarburos sin quemar (-45%), en el monóxido de carbono (-75%), y
el material particulado (-25%). Muchas partículas (64%) para DBCA estuvieron en el rango entre 40 y 560
nm. Por otro lado, muchas de las partículas (94%) para BAJ estuvieron entre 6 y 40 nm. En el rango entre
6 y 40 nm, el diámetro medio másico para BDCA fueron 34.4, 34.7 y 33.3 nm, mientras que para BAJ
fueron 21.3, 18.2 y 20.1 nm para 100, 50 y 10% de carga, respectivamente
Performance and emissions of a heavy duty diesel engine fuelled with palm oil biodiesel and premium diesel
Biodiesels are promoted as alternative fuels due their potential to reduce dependency on fossil fuels and carbon emissions. Research has been addressed in order to study the emissions of light duty vehicles. However, the particle matter and gaseous emissions emitted from heavy-duty diesel engines fueled with palm-biodiesel and premium diesel fuel have seldom been addressed. The objective of this study was to explore the performance and emission levels of a Cummins 4-stroke, 9.5 liter, 6-cylinder diesel engine with common rail fuel injection, and a cooled exhaust gas recirculation (EGR). The palm-biodiesel lowered maximum engine output by much as 10 %. The engine emissions data is compared to standards from 2004, and is determined to pass all standards for diesel fuel, but does not meet emissions standards for PM or NOx for palm-biodieselBiodiesel es promocionado como combustible alternativo para sustituir combustibles de origen fósil y reducir emisiones de carbono. Algunos estudios han sido llevados a cabo para estudiar las emisiones de vehículos diesel de baja potencia. Sin embargo, las emisiones sólidas y gaseosas emitidas por vehículos de trabajo operados con biodiesel de palma africana y diesel de bajo contenido de azufre (~ 15 ppm) han sido poco estudiadas. El objetivo de este estudio fue determinar el desempeño y emisiones de un motor Diesel Cummins, 4 tiempos, 9.5 litros, 6 cilindros con sistema de inyección "common rail", y sistema de recirculación de gases. El motor desarrolló una menor potencia (10 %) cuando fue operado con biodiesel de palma africana. El motor cumplió con la norma ambiental 2004 cuando fue operado con combustible diesel, sin embargo, con biodiesel de palma africana las emisiones de material particulado y los óxidos de nitrógeno estuvieron fuera de norm
Análisis comparativo del desempeño y emisiones de un motor diesel de gran capacidad operando bajo dos escenarios: trabajo en ruta activa y trabajo en banco
Several tests were carried out on a 1,640 kW (2,200 hp) diesel engine operating in two different sets of conditions: a bench test
and route test (when the engine was located on a mining truck). The engine was mounted on a dynamometer for the first set of
conditions. The parameters measured were break torque, cylinder and air inlet temperatures, exhaust gas temperature and both
fuel consumption and airflow. Gas emissions were also recorded. The engine operated during the first phase of the study according
to a test protocol allowing real work conditions to be simulated during a typical cycle present on the operation route. Afterwards,
the mining truck was instrumented for the second set of working conditions and the corresponding monitoring work was
done while the truck was working on the route assigned by the truck's operator. A comparative analysis was then made of the results
obtained in the two sets of working conditions. This analysis led to observing that the results obtained in the two tests had a
very similar pattern and thus led to validating the results obtained in the bench test.La primera revolución académica, llevada a cabo desde finales del siglo XIX en países desarrollados, hace de la investigación una
función universitaria adicional a la tradicional tarea de enseñanza. Una segunda revolución académica intenta transformar la
universidad en una empresa de enseñanza, investigación y desarrollo socioeconómico. El artículo científico llega a ser un excelente
medio práctico para el "movimiento" de nuevo conocimiento entre la universidad y el entorno socioeconómico. Este trabajo
tiene dos propósitos. Primero, presentar algunas consideraciones generales sobre la investigación y el artículo científico. El
segundo, el de dar a conocer una herramienta computacional que sirve para apoyar el proceso de revisión de citaciones bibliográficas
en un artículo científico. Este paso es usualmente realizado a mano y requiere experiencia. El software facilita leer dos
archivos de texto, uno con el contenido del artículo y otro con las referencias bibliográficas, y luego generar un reporte que permite
identificar los autores citados en el texto pero que no están referenciados en la bibliografía, y determinar los autores citados
en la bibliografía mas no citados en el texto del artículo. El software también permite a los investigadores y a los coordinadores
de revistas detectar errores de referenciamiento entre citaciones en el texto y referencias bibliográficas. Los pasos para desarrollar
el software fueron: análisis, diseño, implementación y uso. Para el análisis fue importante la revisión de la literatura sobre elaboración
de citaciones en documentos científicos
Comparative performance and emission tests of a heavy duty off-highway diesel engine working in two different conditions: route test and bench test
Several tests were carried out on a 1,640 kW (2,200 hp) diesel engine operating in two different sets of conditions: a bench test and route test (when the engine was located on a mining truck). The engine was mounted on a dynamometer for the first set of conditions. The parameters measured were break torque, cylinder and air inlet temperatures, exhaust gas temperature and both fuel consumption and airflow. Gas emissions were also recorded. The engine operated during the first phase of the study according to a test protocol allowing real work conditions to be simulated during a typical cycle present on the operation route. Afterwards, the mining truck was instrumented for the second set of working conditions and the corresponding monitoring work was done while the truck was working on the route assigned by the truck’s operator. A comparative analysis was then made of the re- sults obtained in the two sets of working conditions. This analysis led to observing that the results obtained in the two tests had a very similar pattern and thus led to validating the results obtained in the bench test