Esteban Dalmau, Bernat
Total activity: 19
School
Escola d'Enginyeria d'Igualada
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bernat.estebaneei.upc.edu
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1 to 19 of 19 results
  • Environmental assessment of small-scale production of wood chips as a fuel for residential heating boilers

     Esteban Dalmau, Bernat; Riba Ruiz, Jordi Roger; Baquero Armans, Grau; Puig Vidal, Rita; Rius Carrasco, Antoni
    Renewable energy
    Date of publication: 2014-02
    Journal article

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    This work performs a comparative life cycle assessment (LCA) of two fuels for heating boilers, namely wood chips and oil. The LCA methodology allows comparing the environmental impacts of the two analyzed fuels, thus assessing which is environmentally more advantageous. The study is focused on Mediterranean forests located in the Argençola region (Catalonia, northeastern Spain) by applying forest management practices focused to ensure a sustainable exploitation. The direct use of wood chips as a fuel for boilers simplifies notably the number of processes involved in producing such a fuel. The results presented clearly show the environmental benefits of using small-scale produced wood chips instead of fossil oil by analyzing representative impact categories defined by the CML and EDIP methods, even when considering the changes in the carbon stock in the forests under analysis due to the management approach adopted. A sensitivity analysis has also been conducted to assess the impact of the data with higher uncertainty on the final LCA results.

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    Environmental life cycle assessment of rapeseed straight vegetable oil as self-supply agricultural biofuel  Open access

     Baquero Armans, Grau; Esteban Dalmau, Bernat; Puig Vidal, Rita; Riba Ruiz, Jordi Roger; Rius Carrasco, Antoni
    Renewable energy
    Date of publication: 2013-02-01
    Journal article

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    Biofuels are nowadays considered a questionable environmental alternative to fossil fuels. In that context, this work analyses the environmental impacts when introducing rapeseed on the traditional and current wheat and barley agricultural rotation by means of a comparative life cycle assessment (LCA). The introduction of rapeseed, the correctness of its conversion to obtain straight vegetable oil and its use as self-consumption biofuel in tractors are evaluated. Life cycle assessment is used in this work to evaluate the impacts of different considered scenarios. A sensitivity analysis has also been conducted. The results presented show a modest environmental improvement (diminishment of 6 out of the 10 analyzed environmental impacts) when introducing rapeseed to local crop rotations and its partial conversion to oil to be used as fuel in existing diesel engines. Additionally, the ratio between the energy obtained and the total energy input shows moderate positive results when comparing the latter case with the current one. Results from this study can be used to support research and decision making to assess the convenience of introducing alternative fuels in agricultural exploitations

  • Comparative life cycle analysis between traditional and organic farming local rotations to produce straight vegetable oil used as self-supply biofuel in agriculture

     Baquero Armans, Grau; Esteban Dalmau, Bernat; Rius Carrasco, Antoni; Puig Vidal, Rita; Riba Ruiz, Jordi Roger
    European Biomass Conference and Exhibition
    Presentation's date: 2012-06-18
    Presentation of work at congresses

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  • Economic assessment of forest chips versus heating oil in domestic boilers in the mediterranean region

     Esteban Dalmau, Bernat; Baquero Armans, Grau; Riba Ruiz, Jordi Roger; Puig Vidal, Rita; Rius Carrasco, Antoni
    European Biomass Conference and Exhibition
    Presentation's date: 2012-06-18
    Presentation of work at congresses

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  • Study of rapeseed oil degradation in different storage conditions

     Esteban Dalmau, Bernat; Baquero Armans, Grau; Rius Carrasco, Antoni; Puig Vidal, Rita; Riba Ruiz, Jordi Roger
    European Biomass Conference and Exhibition
    Presentation's date: 2012-06-21
    Presentation of work at congresses

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    Temperature dependence of density and viscosity of vegetable oils  Open access

     Esteban Dalmau, Bernat; Riba Ruiz, Jordi Roger; Baquero Armans, Grau; Rius Carrasco, Antoni; Puig Vidal, Rita
    Biomass and bioenergy
    Date of publication: 2012-07
    Journal article

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    The straight use of vegetable oils as fuel in diesel engines entails adjusting several physical properties such as density and viscosity. By adequately heating the vegetable oil before entering the injection system, its physical parameters can reach values very close to that of diesel fuel. Consequently, by properly adjusting the temperature of vegetable oils used as fuel, it is possible to improve their combustion performance, thus avoiding premature engine aging due to incomplete burning. In this study the density and viscosity of several vegetable oils are studied within a wide variety of temperatures. The optimal range of temperatures at which each vegetable oil should operate in order to adjust its properties to those of automotive diesel and biodiesel is then found. Additionally an empirical relationship between the dependence of viscosity with density is presented. Thus, by means of the above-described relationship, through measuring the density of a given oil, its viscosity can be directly deduced

  • Characterization of the surface tension of vegetable oils to be used as fuel in diesel engines

     Esteban Dalmau, Bernat; Riba Ruiz, Jordi Roger; Baquero Armans, Grau; Puig Vidal, Rita; Rius, Antonio
    Fuel (Guildford)
    Date of publication: 2012-12
    Journal article

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    Straight vegetable oils may be used as fuel in existing diesel engines. However, some precautions should be taken into account because some of their physicochemical properties must be adjusted through tem- perature control to ensure enhanced combustion, thus avoiding premature aging of the engine. Although it is well known that surface tension plays a prevalent role in the fuel atomization process which affects the combustion quality, there is lack of published information about its variation with temperature when dealing with straight vegetable oils to be used as fuel in unmodified diesel engines. In this work, the surface tension of several vegetable oils is studied in a wide temperature interval. The optimal range of temperatures at which each vegetable oil should operate to adjust its properties to those of automotive diesel and biodiesel is found. Moreover, an empirical relationship between the dependence between surface tension and density is presented

  • LCA of forest chips versus diesel boilers in the Mediterranean region

     Esteban Dalmau, Bernat; Baquero Armans, Grau; Puig Vidal, Rita; Riba Ruiz, Jordi Roger; Rius Carrasco, Antoni
    European Biomass Conference and Exhibition
    Presentation's date: 2011-06-09
    Presentation of work at congresses

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    ABSTRACT: Obtaining energy from forest chips is a technology widely used in many regions. There are currently many studies and applications on the use of forest biomass [1,2], mainly promoted by policies aimed to reduce greenhouse gases. The forests of the Mediterranean area are characterized by a mountain relief. This orography makes difficult the selective biomass extraction from the forest. Thus, the biomass is accumulated in the forest and becomes a serious danger for wildfires. Forest fires are considered the most important natural impact in the Mediterranean region due to its effect to ecosystems, as some authors state [3,4]. This study aims to compare by means of LCA methodology the use of forest chips and diesel fuels in a boiler, focusing on the difficulty of extracting the wood from a Mediterranean forest area. In the Mediterranean area there are no environmental studies centred on the extraction of timber from forest areas without affecting the life in the forest. This work presents an LCA, where the difficulties of extracting the biomass from the forest and its use in heating boilers are presented.

  • Sustainability assessment of straight vegetable oil used as self-supply biofuel in agriculture

     Baquero Armans, Grau; Esteban Dalmau, Bernat; Puig Vidal, Rita; Riba Ruiz, Jordi Roger; Rius Carrasco, Antoni
    European Biomass Conference and Exhibition
    Presentation's date: 2011-06-09
    Presentation of work at congresses

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    This work proposes and analyses a model for an agricultural fuel self-supply exploitation. The model is based on the current extended crop rotation of wheat and barley in Anoia region (Catalonia, Spain). The introduction of rapeseed to the current crop rotation and its conversion into oil to be used as agricultural fuel is presented. Life cycle assessment methodology is used to carry out an environmental and an economic assessment. Environmental results show a preference for the vegetable oil based scenario in terms of CO2 equivalent emissions and energy consumption as well as no major difference in land used for the considered scenarios. Economic assessment shows a preference for the rapeseed introduction in the current crop rotation agricultural system without converting the seed into oil and using it as biofuel. The basis to develop the life cycle social assessment is also presented, calculating a social impact category as an example.

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    An eddy-current-based sensor for preventing knots in metallic wire drawing processes  Open access

     Esteban Dalmau, Bernat; Riba Ruiz, Jordi Roger; Baquero Armans, Grau
    Nondestructive testing and evaluation
    Date of publication: 2011-04-07
    Journal article

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    During metallic wire drawing processes, the presence of knots and the failure to detect them can lead to long production interruptions, significant economic losses and a lower quality of final product. Consequently, there is a pressing need to develop methods for real-time detection and prevention of this fault. In this paper, a sensor to prevent the formation of knots during the metallic wire drawing process is presented and evaluated by means of experimental data. This fast, inexpensive, non-contact sensor is based on electromagnetic principles such as eddy current induction, magnetic reluctance variations and magnetic coupling. The proposed sensor without direct contact can detect knots in a target metallic wire by measuring the impedance variations of a calibrated sensing coil caused by either a knot or an unwound loop rising from a wire rod. The incorporation of this type of sensor into a wire-drawing machine can avoid the tightening of the knot, thereby reducing downtime and increasing the security and reliability of the process. Experiments were conducted using a scale model of the above proposed system. This allowed highlighting the sensor’s potential by carrying out an automatic, real-time knot detection during steel wire drawing

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    An evaluation of the life cycle cost of rapeseed oil as a straight vegetable oil fuel to replace petroleum diesel in agriculture  Open access

     Baquero Armans, Grau; Esteban Dalmau, Bernat; Riba Ruiz, Jordi Roger; Rius Carrasco, Antoni; Puig Vidal, Rita
    Biomass and bioenergy
    Date of publication: 2011-08
    Journal article

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    The use of straight vegetable oil (SVO) as biofuel has been recognized as a valid substitute of diesel fuel in the agricultural sector under specific circumstances. Its direct use reduces most of the chemical processes involved when converting it into biodiesel, thus lowering harmful emissions. This study presents the economic analysis of a self-supply farming model that uses rapeseed as its fuel base. This model addresses agricultural environmental concerns and can even minimize dependence on the fluctuating costs of diesel fuel. The use of SVO in agriculture can help reduce farmers’ vulnerability to fossil fuel prices. The economic evaluation of the model proposed in this study shows clear economic benefits of introducing rapeseed to the traditional crop rotation of wheat and barley. The key factors analyzed in this model are diesel fuel price, diesel fuel grants and crop aids. The current situation in Spain favors the use of diesel fuel in agriculture rather than rapeseed SVO due to an 8% profit difference. However, results show that changes in key factors slightly affect the profit margin, calculating a difference of only 3.7% for particular factor combinations. Combined environmental-friendly agriculture supporting policies are necessary to cover this slight profit difference to promote this biofuel

  • Is it environmentally advantageous to use vegetable oil directly as biofuel instead of converting it to biodiesel?

     Esteban Dalmau, Bernat; Baquero Armans, Grau; Puig Vidal, Rita; Riba Ruiz, Jordi Roger; Rius Carrasco, Antoni
    Biomass and bioenergy
    Date of publication: 2011-03
    Journal article

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    Use of Rapeseed Straight Vegetable Oil as Fuel Produced in Small-Scale Exploitations  Open access

     Baquero Armans, Grau; Esteban Dalmau, Bernat; Riba Ruiz, Jordi Roger; Puig Vidal, Rita; Rius Carrasco, Antoni
    Date of publication: 2011-08-01
    Book chapter

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    This chapter presents a method to produce rapeseed and process it to obtain rapeseed oil and rapeseed cake meal from a small-scale point of view. It also shows how rapeseed oil can be used as fuel in diesel engines for agriculture self-consumption. A production, processing and use-as-fuel model for rapeseed oil is also presented, analysing environmentally and economically the use of rapeseed oil as fuel compared to other agricultural production alternatives. The results are evaluated for dry Mediterranean area conditions

  • Viabilitat tècnica i ambiental de biocombustibles: oli de colza i estella forestal  Open access

     Esteban Dalmau, Bernat
    Defense's date: 2011-07-06
    Department of Mechanical Engineering, Universitat Politècnica de Catalunya
    Theses

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    La dependència actual dels combustibles fòssils en la majoria de sectors industrials i domèstics no és sostenible ni a curt ni a llarg termini. Això està obligant a plantejar alternatives a la majoria de sectors industrials especialment encaminades a l’estalvi energètic i la utilització d’energies renovables. A més a més en el cas dels combustibles, la Unió Europea està incentivant l’ús de biocarburants degut als compromisos assumits en el protocol de Kyoto. Els biocarburants més comuns pel cas del transport són el biodièsel i el bioetanol, que en la majoria dels casos, es produeixen a gran escala i presenten seriosos problemes ambientals i socials tal i com citen els treballs de diversos autors. En aquest escenari és interessant proposar i avaluar ambientalment altres biocarburants no presents actualment en el mercat. En aquesta tesi es proposen i s’avaluen ambientalment (mitjançant l’anàlisi del cicle de vida, ACV) dos biocombustibles, l’oli de colza pel cas del transport, comparat amb la seva conversió a biodièsel i l’estella forestal per a calefacció comparada amb el gasoil. En l’últim apartat d’aquesta tesi es realitza una caracterització de sis olis vegetals, per tal de determinar la temperatura òptima de preescalfament per ser utilitzats com a biocombustibles en motors dièsel actuals. Conjuntament amb aquesta caracterització es parametritza la densitat, viscositat i tensió superficial d’aquests olis en funció de la temperatura.

    La dependencia actual de los combustibles fósiles en la mayoría de sectores industriales y domésticos no es sostenible ni a corto ni a largo plazo. Esto está obligando a plantear alternativas a la mayoría de sectores industriales especialmente encaminados al ahorro energético y la utilización de energías renovables. Además en el caso de los combustibles, la Unión Europea está incentivando el uso de biocarburantes debido a los compromisos asumidos en el protocolo de Kioto. Los biocarburantes más comunes en el caso del transporte son el biodiesel y el bioetanol, que en la mayoría de los casos, se producen a gran escala y presentan serios problemas ambientales y sociales tal y como citan los trabajos de varios autores. En este escenario es interesante proponer y evaluar ambientalmente otros biocarburantes no presentes actualmente en el mercado. En esta tesis se proponen y se evalúan ambientalmente (mediante el análisis del ciclo de vida, ACV) dos biocombustibles, el aceite de colza por el caso del transporte, comparado con su conversión a biodiesel i l' forestal para calefacción comparada con el gasóleo. En el último apartado de esta tesis se realiza una caracterización de seis aceites vegetales, para determinar la temperatura óptima de precalentamiento para ser utilizados como biocombustibles en motores diesel actuales. Conjuntamente con esta caracterización se parametriza la densidad, viscosidad y tensión superficial de estos aceites en función de la temperatura

    The current dependence on fossil fuels in most industrial and domestic sectors is not sustainable in neither short nor long term. This is promoting alternatives to most industries, especially focused on saving energy and using renewable energy. Moreover, the European Union is encouraging the use of biofuels trough the commitments in the Kyoto Protocol. The most common biofuels for transport are biodiesel and bioethanol, which in most cases, are large scale produced and involve serious environmental and social problems according to several authors. In this scenario it is interesting to evaluate other alternative fuels, being environmentally friendly and not currently present in the market. This thesis presents and environmentally analyses two biofuels using life cycle assessment (LCA) methodology. One is straight vegetable rapeseed oil used for truck transport compared to rapeseed biodiesel. The other is wood chips for heating compared to diesel as heating fuel. In the last section of this PjD a characterization of six vegetable oils is performed in order to determine the optimal preheating temperature to use it as biofuel in current diesel engines. Together with this characterization, the density, the viscosity and the surface tension of different vegetable oils are parameterized for a wide range of temperature.

  • Tècnica de grup d'experts aplicat a l'assignatura de materials  Open access

     Esteban Dalmau, Bernat; Baquero Armans, Grau
    Jornada d'Innovació Docent UPC
    Presentation's date: 2010-07-01
    Presentation of work at congresses

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    Small-scale production of straight vegetable oil from rapeseed and its use as biofuel in the Spanish territory  Open access

     Baquero Armans, Grau; Esteban Dalmau, Bernat; Rius Carrasco, Antoni; Riba Ruiz, Jordi Roger; Puig Vidal, Rita
    Energy policy
    Date of publication: 2010-01
    Journal article

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    Biofuels nowadays are an important topic of study. The most significant point is the availability of bioethanol or biodiesel and their production from different raw materials. It is already known that large scale production of first-generation biodiesel cannot be seen as an alternative to fossil fuels due to land requirements, competition with food, increase in fertilizer requirements and pressure on tropical forests among others. This fact does not necessarily apply to second-generation biofuels or small scale niche productions. Straight vegetable oil (SVO) can be used directly in diesel engines with minor modifications. Our proposal is a small-scale SVO production system for self-supply in agricultural machinery. In this paper a model to provide SVO to local farmers in a specific area in Catalonia (Spain) is presented. We also present a discussion about the regulations to be changed in order to make possible the incorporation of SVO as engine fuel in diesel vehicles and a comparative analysis between the emissions of tractors fed with SVO and petrodiesel. Moreover a quantitative economic analysis of modifying diesel engines and long-term operability costs are shown and a firstrun economic analysis comparing the actual crop rotation with the proposed one and some alternatives is studied.

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  • Utilització de l'oli de colza com a biocarburant en explotacions agrícoles

     Esteban Dalmau, Bernat; Baquero Armans, Grau; Puig Vidal, Rita; Riba Ruiz, Jordi Roger; Rius Carrasco, Antoni
    Date: 2010-01-01
    Report

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    La utilització de l’oli de colza com a carburant és una tecnologia que ja s’utilitza a altres països europeus com Alemanya i Dinamarca, degut principalment a dos factors: el gasoil agrícola està menys subvencionat i el grau de conscienciació mediambiental és major en aquest països. L’oli de colza és un biocarburant que s’obté del premsat de llavors de plantes oleaginoses i que, realitzant una petita modificació al sistema d’alimentació dels motors dièsel, pot ser utilitzat com a combustible. La fabricació de l’oli vegetal en front a la del biodièsel és més senzilla, ja que inclou menys processos i menys consum energètic. [1] En aquesta fitxa es pretén fer una breu explicació de la producció i consum de l’oli de colza, destinat a ser utilitzat directament com a biocarburant en maquinària agrícola. Ens centrarem en l’oli fabricat a partir de la llavor de colza, ja que possiblement és la planta oleaginosa que millor s’adapta al clima mediterrani.

  • Estudi econòmic de l'oli de colza com a biocarburant en explotacions agrícoles

     Baquero Armans, Grau; Esteban Dalmau, Bernat; Puig Vidal, Rita; Riba Ruiz, Jordi Roger; Rius Carrasco, Antoni
    Date: 2010-01-01
    Report

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    Actualment els biocarburants ocupen una important àrea d’estudi, essent el biodièsel i el bioetanol els més utilitzats en el nostre territori. La major part d’aquests biocarburants són de primera generació i la seva fabricació a gran escala presenta seriosos problemes ambientals i socials a causa de la gran demanda de terres agrícoles [1-2]. Tot i això, la necessitat de reduir l’emissió de gasos d’efecte hivernacle n’incrementa la seva demanda. Actualment, és interessant pensar en implementar altres biocarburants no presents al mercat espanyol, com és el cas de l’oli vegetal fabricat a petita escala. La producció d’oli vegetal és més senzilla que la de biodièsel, doncs inclou menys processos i menys consum energètic. L’oli vegetal obtingut del premsat de llavors de plantes oleaginoses es pot usar com a biocarburant realitzant una petita modificació al sistema d’alimentació dels motors dièsel convencionals. En alguns països europeus, com Alemanya i Dinamarca, ja s’utilitza l’oli vegetal com a biocarburant, principalment en maquinària agrícola, mentre que a Espanya no es troba a les gasolineres i només el fan servir alguns particulars [3]. Aquesta fitxa mostra els resultats econòmics de la introducció de la colza en la rotació de conreus clàssica a la zona de l’Anoia i l’autoconsum de l’oli de colza com a biocarburant en maquinària agrícola. Els resultats s’han obtingut mitjançant un model desenvolupat per a calcular el benefici obtingut en una explotació a partir de paràmetres com els rendiments de les collites de la zona de l’Anoia. Es considera l’oli fabricat a partir de la llavor de colza, ja que és possiblement la planta oleaginosa que millor s’adapta al clima mediterrani.

  • Characterization of physical properties of vegetable oils to be used as fuel in diesel engines

     Riba Ruiz, Jordi Roger; Esteban Dalmau, Bernat; Baquero Armans, Grau; Puig Vidal, Rita; Rius Carrasco, Antoni
    Afinidad: revista de química teórica y aplicada
    Date of publication: 2010-10-06
    Journal article

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