Time filter

Source Type

Marti-Herrero J.,Center Internacional Of Metodes Numerics En Enginyeria Cimne | Marti-Herrero J.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | Alvarez R.,IIDEPROQ | Cespedes R.,Estacion Experimental de Choquenaira | And 3 more authors.
Bioresource Technology | Year: 2015

The aim of this research is to evaluate the co-digestion of cow and llama manure combined with sheep manure, in psychrophilic conditions and real field low cost tubular digesters adapted to cold climate. Four digesters were monitored in cold climate conditions; one fed with cow manure, a second one with llama manure, the third one with co-digestion of cow-sheep manure and the fourth one was fed with llama-sheep manure. The slurry had a mean temperature of 16.6°C, the organic load rate was 0.44kgvsm-3d-1 and the hydraulic retention time was 80days. After one hundred days biogas production was stable, as was the methane content and the pH of the effluent. The co-digestion of cow-sheep manure results in a biogas production increase of 100% compared to the mono-digestion of cow manure, while co-digestion of llama-sheep manure results in a decrease of 50% in biogas production with respect to mono-digestion of llama manure. © 2015 Elsevier Ltd.


Marti-Herrero J.,Center Internacional Of Metodes Numerics En Enginyeria Cimne | Marti-Herrero J.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | Ceron M.,Cologne University of Applied Sciences | Garcia R.,Valle Private University | And 3 more authors.
Energy for Sustainable Development | Year: 2015

The aim of this paper is to understand the influence of the user behavior on tubular digesters performance, through a technical and a social approach in the Bolivian context. Fifteen domestic digesters were evaluated, from which 6 were installed in the Altiplano and other 6 in the Andean Valleys. Data about slurry temperature, feedstock and biogas quality were collected from these 12 digesters, while daily biogas production and feeding pattern were also monitored from further three digesters in the valleys. Because of changes in user behavior along the monitoring period and particular characteristics of the digesters monitored, 5 complete patterns of biogas production and digester management were established. Furthermore, the results of a socio-cultural study with Andean families about the perception of poverty, their needs and the role played by digesters in their expectations in improving life quality, are correlated to the obtained technical data. The technical evaluation shows how the digester management seems to have a seasonal performance throughout the year according to the agricultural calendar. This means that families are more interested in using bioslurry in crops and agricultural improvements than in the use of biogas. The Bolivian government subsidy on liquefied gas seems to be one of the key issues to understand these results. Finally, data also reveals how the thermal behavior of tubular digesters adapted to cold climate that use a passive solar design, is similar to the thermal behavior of valley digesters, and therefore intends to add the same passive heating techniques for warm and tropical climates, to increase slurry temperatures and achieve a higher biogas production. © 2015 International Energy Initiative.


Cipriano X.,Center Internacional Of Metodes Numerics En Enginyeria Cimne | Vellido A.,Polytechnic University of Catalonia | Cipriano J.,Center Internacional Of Metodes Numerics En Enginyeria Cimne | Marti-Herrero J.,Center Internacional Of Metodes Numerics En Enginyeria Cimne | And 2 more authors.
Energy Efficiency | Year: 2016

In recent years, big efforts have been dedicated to identify which are the factors with highest influence in the energy consumption of residential buildings. These factors include aspects such as weather dependence, user behaviour, socio-economic situation, type of the energy installations and typology of buildings. The high number of factors increases the complexity of analysis and leads to a lack of confidence in the results of the energy simulation analysis. This fact grows when we move one step up and perform global analysis of blocks of buildings. The aim of this study is to report a new methodology for the assessment of the energy performance of large groups of buildings when considering the real use of energy. We combine two clustering methods, Generative Topographic Mapping and k-means, to obtain reference dwellings that can be considered as representative of the different energy patterns and energy systems of the neighbourhood. Then, simulation of energy demand and indoor temperature against the monitored comfort conditions in a short period is performed to obtain end use load disaggregation. This methodology was applied in a district at Terrassa City (Spain), and six reference dwellings were selected. Results showed that the method was able to identify the main patterns and provide occupants with feasible recommendations so that they can make required decisions at neighbourhood level. Moreover, given that the proposed method is based on the comparison with similar buildings, it could motivate building occupants to implement community improvement actions, as well as to modify their behaviour. © 2016 Springer Science+Business Media Dordrecht


Garfi M.,Polytechnic University of Catalonia | Marti-Herrero J.,Center Internacional Of Metodes Numerics En Enginyeria Cimne | Marti-Herrero J.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | Garwood A.,Green Empowerment | Ferrer I.,Polytechnic University of Catalonia
Renewable and Sustainable Energy Reviews | Year: 2016

This review aims to provide an overview of household biogas digester implementation in rural areas of Latin America. It considers the history of household digesters in Latin America, including technical, environmental, social and economic aspects. Several successful experiences have been promoted during the last decade, including the creation of the Network for Biodigesters in Latin America and the Caribbean (RedBioLAC) that provides a forum to coordinate implementation and research programmes throughout the continent. Although the potential of this technology is well demonstrated, some barriers are identified, such as the need for technical improvements, lack of social acceptance and high investment costs. Thus, further efforts should be undertaken to overcome these barriers and improve the technical performance, social acceptance, economic benefits and environmental impact in order to enhance its wide-spread dissemination in energy poor communities. © 2016 Elsevier Ltd. All rights reserved.


Marti-Herrero J.,Center Internacional Of Metodes Numerics En Enginyeria Cimne | Marti-Herrero J.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | Flores T.,Valle Private University | Alvarez R.,IIDEPROQ | Perez D.,Center Internacional Of Metodes Numerics En Enginyeria Cimne
Biomass and Bioenergy | Year: 2016

The aim of this research was to evaluate the error originated when biogas production from field monitoring digesters, influenced by the diurnal temperature cycle, was normalized to standard conditions for pressure and temperature (273.15 K and 100 kPa) from local conditions. The biogas production data is often reported without indicating if done under local conditions, whether these conditions have been standardized and, if they have actually been standardized, the standard temperature and pressure is not indicated. In this research ambient and biogas temperature, as well as biogas production were monitored with a 30 min frequency during three consecutive days, in three different tubular digesters. Normalization was realized using the high frequency data collected as reference values, and also using daily biogas production with mean daily biogas, ambient and nearby meteorological station temperatures. The outcome of this research shows that normalization of biogas production can be obtained using daily biogas production and the daily mean ambient temperature with an overestimation by no more than 1.5%, in comparison to the normalization achieved by using high frequency data from biogas temperature and production. Using mean daily ambient temperature or mean daily biogas temperature results in the same overestimation, while using mean daily ambient temperature from a nearby airport weather station pushes the overestimation up to 2.7%. So, if ambient temperature and altitude is identified, biogas production reported in local conditions can be normalized. © 2015 Elsevier Ltd.


Villacis S.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | Martinez J.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | Riofrio A.J.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | Carrion D.F.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | And 3 more authors.
Energy Procedia | Year: 2015

The efficient use of energy is a priority when a technology migration plan is being executed. Several factors must be taken into account in order to achieve this goal. In this paper the migration from liquefied petroleum gas based cookers to electric induction cookers is analyzed, emphasizing on the selection of the best material to produce the cookware suitable for induction cookers in terms of energy saving and performance. To accomplish this study, several tests have been performed in three kind of pots made of different materials: stainless steel, cast iron and aluminium. These tests have allowed to evaluate some material properties as rust resistance, structural stability of pot bottom under thermal impact conditions, energy efficiency measurements in different body cookware materials, energy efficiency with different distances between induction zone and pot bottom, relation between energy efficiency and initial measurements of concavity/convexity and energy efficiency before and after thermal impact conditions. After completing this research, it has been found that the enameled cast iron and the stainless steel present higher efficiency in the same stove. © 2015 The Authors. Published by Elsevier Ltd.


Rivera-Tapia E.D.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | Fajardo C.A.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | Avila-Vega A.J.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | Avila C.F.,National Polytechnic School of Ecuador | And 5 more authors.
Fullerenes Nanotubes and Carbon Nanostructures | Year: 2016

A solid state synthesis of boron carbon nitride oxide (BCNO) material was carried out starting from urea and boric acid treated at 600°C. The X-ray diffraction pattern corresponded to amorphous BCNO with an interlayer distance of 3.49 Å. The material had a layered structure similar to that of graphite and hexagonal boron nitride (h-BN). Infrared spectroscopy (IR) showed bands which were similar to those typical of BN and carbon nitride. The presence of boron was also confirmed by energy dispersive spectroscopy in an amount compatible with the IR spectrum. The spectra obtained by X-ray photoelectron spectroscopy (XPS) corresponded to those of a BCNO family with a considerable content of oxygen too. The optical band gap was estimated to be 3.22 eV, typical of a wide band-gap semiconductor. The particle size was very dispersed from micro to nanosize. The material dispersed in polar solvents formed stable suspensions due to the presence of hydroxyl groups. © 2016 Taylor & Francis Group, LLC.


Guayanlema V.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | Espinoza S.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner | Ramirez A.D.,ESPOL Polytechnic University | Nunez A.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner
WIT Transactions on Ecology and the Environment | Year: 2014

This paper reports the current status of greenhouse gas (GHG) emissions caused by the transport sector in Ecuador and possible mitigation scenarios to reduce them. In the first case, the emissions were quantified by using the IPCC methodology for National GHG Inventories which is based in the quantification of the oil products consumption (TIER 1). The emission estimations have revealed that nearly 33,400 kton CO2-Eq were emitted in 2012. The same year, road transport was identified as the most important sub-sector in terms of CO2emissions with a contribution of 90%. Road transport emission is followed by aviation and navigation, both not exceeding 10% of emissions within the transport sub-sector. These pollution trends have grown at a rate of about 6% (referred to ton of CO2-Eq.). As consequence, several initiatives and research projects have been undertaken with the aim of finding solutions to the current situation in the transport sector. Secondly, an analysis of GHG emissions trends was performed (according to the business as usual scenario) based on historical GHG emission inventories updated to the year 2012. This analysis was designed using the software Long-range Energy Alternative Planning (LEAP). For this purpose, Governmental strategies including measures related to fuel consumption, use of new technologies, political actions such as scrapping of the vehicle that have completed their life cycle, the introduction of hybrid and electric automobiles were considered. Preliminary results of the analysis indicate that political actions like scrapping vehicles and the use of biofuels are the most promising solutions to reduce rising trends of emissions and energy consumption. © 2014 WIT Press.

Loading Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner collaborators
Loading Instituto Nacional Of Eficiencia Energetica Y Energias Renovables Iner collaborators