Rocio Maceiras - Academia.edu (original) (raw)

Papers by Rocio Maceiras

European Journal of Engineering Education, 2012

Reda Abdulaal Nidhal Abdulaziz Wisam Abu Jadayil James Abulencia Araceli Adam Olusola Adesope Ped... more Reda Abdulaal Nidhal Abdulaziz Wisam Abu Jadayil James Abulencia Araceli Adam Olusola Adesope Pedro Luis Aguado Alison Ahearn Aoife Ahern Tony Ahfock Ali Al-Bahi Firoz Alam Katariina Alha Esat Alpay Burkhard Alpers Anabela Alves José Jaílson Alves Catherine Amelink Jane Andrews Nana Kofi Annan Arif Anwar Alireza Asgari Giuliano Augusti Aris Avdelas Robert Ayres Barbara Bagilhole Balamuralithara Balakrishnan Moshe Barak Sarah Barnard Ricardo Barros Raphaël Bary Adnan Bashir Samuel Bassetto Ipshita Basu Hoda Baytiyeh Frank Becker Kacey Beddoes Robert Benavente Jens Bennedsen Ineke Berq Anders Berglund Enrique Berjano Jonte Bernhard Ragbir Bhathal Manpreet Bhatti Zhuming Bi Sylvio Bistafa Aaron Blicblau Wim Blokzijl Cyril Boateng Maartje Van Den Bogaard Steffen Bohrmann Alejandra Boni Jose Borges Maura Borrego Brian Bowe Lyn Brodie Erik Brogt Christian Byrge Edmond Byrne C.R. Rachana Angel Cámara Rascón

International Journal of Environmental Research, 2016

Wastewater contains many organic and inorganic contaminants that can cause serious damage to the ... more Wastewater contains many organic and inorganic contaminants that can cause serious damage to the environment and health of people, Therefore, they have to be eliminated before being downloaded into sensitive areas. Different methods of wastewater purification have been used for contaminants removal. However, they present some technical and economic limitations. Thus, new methods of nutrients removal by microalgae based on phytoremediation techniques, become promising methods due to its viability. The objective of wastewater treatment is to improve and purify the water. For that, the removal of all or some of the nutrients present in water is carried out, resulting in a reusable or suitable water to be returned to its natural environment. This study investigates the capacity of Chlorella Vulgaris microalga as a potential candidate for removing the phosphorous and organic matter from wastewater. The strain of microalga was cultivated in synthetic wastewater at room temperature with ar...

International Journal of Environmental Research, 2018

Soil contamination by hydrocarbons is an environmental problem and its remediation is necessary. ... more Soil contamination by hydrocarbons is an environmental problem and its remediation is necessary. This work presents the effect of ultrasound on solvent extraction of soil contaminated with diesel fuel. For the experiments, the soil was contaminated with diesel (10% wt.). The remediation was carried out by ultrasonic solvent extraction and compared with Soxhlet extraction. The effect of different parameters (time, temperature, soil/solvent ratio and type of solvent) on removal efficiency was examined. With the aim to optimize the ultrasonic extraction, a Box-Behnken design under response surface methodology was used and the proposed model showed a good fit of the experimental data. The obtained results were compared with a conventional solvent extraction (Soxhlet) for both solvents (n-hexane and acetone). Moreover, the phytotoxic effect of soil after remediation treatment was observed on seed germination of Brassica rapa. The obtained results demonstrated that hexane was more effective than acetone in removing hydrocarbons from contaminated soil (80%), and the removal efficiency increased with the soil/solvent ratio ([ 1:5) and reaction time ([ 90 min). A secondorder polynomial model was proposed to predict the removal efficiency of the extraction process.

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2016

ABSTRACT Biodiesel is renewable and environmental friendly, with calorific value equivalent to reg... more ABSTRACT Biodiesel is renewable and environmental friendly, with calorific value equivalent to regular fossil fuel. This fuel can be produced from a variety of feedstocks, such as first-generation biodiesel feedstock (corn, peanut, soybean), second generation (jatropha, animal fats, waste cooking oils, macroalgae), and third generation (microalgae). Among these feedstocks, biodiesel production from microalgae has drawn special attention for different reasons: they have high lipid content and high growth rates; they are tolerant to severe environmental conditions; they offer the possibility of sequester carbon dioxide from the flue gases; their harvesting and transportation are economical compared to other crops; and they have very high photosynthetic yields compared to other terrestrial plants. The advantage of using macroalgae recollected on the beaches as raw material is that allows to obtained energy from a residue. Microwave-assisted extraction and transesterification of microalgae is being researched as a solution for biodiesel production by its benefits, such as shorter reaction times and less amount of heat energy to obtain biodiesel. It is due to the fact that microwaves can easily penetrate through the cell wall structure to extract and transesterify the oils into biodiesel. The aim of this research was to explore the possibility of carrying out the microwave-assisted transesterification of three marine macroalgae (brown and green). Different experimental runs were carried out with different process parameters such as macroalgae-to-methanol ratio, reaction time and catalyst concentrations. Based on the obtained results, the best conditions for microwave-assisted transesterification reaction were macroalgae-to-methanol ratio of 1:15 (wt/vol), sodium hydroxide concentration of 2 wt% and reaction time of 3 min.

DYNA, 2015

This paper describes a vehicle simulation toolbox developed under Matlab® environment, which can ... more This paper describes a vehicle simulation toolbox developed under Matlab® environment, which can be used to estimate the range of a vehicle battery, or a fuel cell/battery hybrid system. The model is function of mechanical and physical variables that depend not only on the vehicle but also on the ground. This toolbox can be extended to GPS tracking files by means of reading data file plug-ins. Even standard drive cycles can be simulated. Battery and hydrogen consumption, hydrogen storage tank level, battery state of charge, power consumption and fuel cell energy production, maximum range and maximum number of cycles for a real route can be determined. The model facilitates the prediction of the vehicle range and the hydrogen and energy consumption. Real route simulation gives a good approximation of the vehicle speed close to real-life services instead of using driving cycles that are quite arbitrary approximations to a real route.

Chemical Engineering Transactions

Microalgae culture is a potential source of biodiesel and one of the best alternatives as raw mat... more Microalgae culture is a potential source of biodiesel and one of the best alternatives as raw material for biodiesel production. The first objective of this work is the pilot plant design for microalgae culture of high oil content species. The design was inspired by raceway large-scale culture. Although this kind of culture is usually in outdoor ponds, the pilot plant is an indoor raceway pond, therefore, it was necessary to design the lighting system and, also, the stirring system. The designed device was tested with Isochrysis Galbana clon T-Iso semi-continuous culture. Finally, microalgae oil was extracted and this oil was suitable for biodiesel production.

Chemical Engineering Transactions

Huge efforts have been carried out in recent years in order to develop an alternative fuel from r... more Huge efforts have been carried out in recent years in order to develop an alternative fuel from renewable resources, such as biodiesel fuel. Therefore, the use of cooking oil as raw material is a very interesting alternative for the production of biodiesel. In this work, waste frying oil was used as raw material for enzymatic biodiesel production. Moreover, this study analyzes the influences of the type of enzymatic catalyst on the conversion of methyl esters, as well as the influence of other variables such as reaction time.

European Journal of Sustainable Development, 2015

This paper presents a toolbox for the simulation of a zero emission urban hybrid bus, which combi... more This paper presents a toolbox for the simulation of a zero emission urban hybrid bus, which combines batteries and fuel cells. This type of vehicle performs predefined routes with a certain frequency, then they are an ideal option to the replacement of combustion engines with renewable energy systems. The simulation of these vehicles can be made for different standard driving cycles (ECE-15, EUDC, NEDC, SFUDS) or for real routes from GPS device data. This will allow to consider the orography of the route, considering the slope that overcomes the vehicle at each time, generally this parameter is not included in other models, and it could become a determining factor for the applicability of these vehicles on certain specified routes. Moreover, this tool lets to study and to analyse other not easily quantifiable factors, such as the weather or peak-hour traffic. Finally, the performance of an urban hybrid bus was investigated to assess its theoretical range and the technical feasibility of zero-emission vehicles.

European Journal of Sustainable Development, 2015

Hydrogen shows very interesting features for its use on-board applications as fuel cell vehicles.... more Hydrogen shows very interesting features for its use on-board applications as fuel cell vehicles. This paper presents the modelling of a tank with a metal hydride alloy for on-board applications, which provides good performance under ambient conditions. The metal hydride contained in the tank is Ti0.98Zr0.02V0.43Fe0.09Cr0.05Mn1.5. A two-dimensional model has been performed for the refuelling process (absorption) and the discharge process (desorption). For that, individual models of mass balance, energy balance, reaction kinetics and behaviour of hydrogen gas has been modelled. The model has been developed under Matlab / Simulink© environment. Finally, individual models have been integrated into a global model, and simulated under ambient conditions. With the aim to analyse the temperature influence on the state of charge and filling and emptying time, other simulations were performed at different temperatures. The obtained results allow to conclude that this alloy offers a good behaviour with the discharge process under normal ambient conditions.

European Journal of Sustainable Development, 2015

An increasing global demand for a biologically produced energy source has emerged due to the exha... more An increasing global demand for a biologically produced energy source has emerged due to the exhausted usage of non-renewable petroleum-derived fuels. Microalgae are a promising feedstock for biofuels because of their capability to produce lipids. In this paper, two operations for biodiesel production were studied from Phaeodactylum Tricornutum microalgae. This marine diatom shows a big potential to produce biodiesel due to its fast growth and lipid accumulation ability. In this research, first the microalgae was harvesting using an inorganic flocculant as copper (II) sulphate (CuSO4). When the dose was 200 mg/L, the microalgae recovery was close 83% in the first five minutes. After that, the microalgal oil was separated by ultrasound extraction process, using ethanol as solvent. This allows to analyze the oil content of the microalgae which is used later in the transesterification. The obtained lipid content was 38% wt. Temperature variations were observed in this process. Finally, a direct transesterification reaction took place with base catalysis by three ways: traditional, microwave assisted and ultrasound assisted. Direct transesterification microwave assisted achieved 52% conversion to biodiesel versus 16% for the traditional method. However, the best performance (90%) was obtained for ultrasound assisted transesterification.

European Journal of Sustainable Development, 2015

This study investigates the effect of ultrasounds in conversion of waste frying oil into biodiese... more This study investigates the effect of ultrasounds in conversion of waste frying oil into biodiesel. Many researchers have studied the use of ultrasounds in the biodiesel production from different feedstock; however, there are few studies focused on the biodiesel production from waste frying oil. In this research, ultrasound-assisted transesterification was carried out to convert the waste frying oil into biodiesel directly. The effect of different process parameters such as reaction time (30-90 min), amount of catalyst (0.5-1% wt. NaOH) and temperature (20-40 ºC) were also analyzed to obtain the higher conversion. A methanol to oil molar ratio of 6:1, 0.5% amount of catalyst and 30 ºC was enough to complete the process in 60 min. The obtained results in this study confirm that that ultrasound-assisted transesterification was a fast and efficient method for biodiesel production from waste frying oil even if reaction temperature is low.

European Journal of Sustainable Development, 2015

An alternative for biodiesel production is the use of lipids from microalgae. Although all steps ... more An alternative for biodiesel production is the use of lipids from microalgae. Although all steps to obtain this biofuel are important, harvesting and extraction are the most important. Advances in these areas are necessary in order to obtain third-generation fuels. The purpose of the present study is to compare different methods of lipids extraction and harvesting for freshwater Selenastrum Capricornutum microalgae. The method used for harvesting was flocculation with inorganic agent. Copper (II) Sulphate (CuSO4) was used as flocculant, resulting in the best percentage of recovery (76%) for a dose of 2 g/L. Previously oil extraction, the collected samples were homogenized and their moisture content was analysed obtaining values of 55-96%. Two extraction methods were used: Soxhlet and ultrasound. The use of ultrasound favours cell disruption and increases the extraction yield. In extraction methods, polar, non-polar solvents, and mixes of solvents were used. N-hexane and acetone were used as solvents for Soxhlet extraction, and ethanol, acetone, methanol, chloroform, and a mixture of chloroform and methanol in 1:2 and 2:1 ratios, for extraction ultrasound assisted method. The use of the methanol-assisted ultrasound is the most efficient method for lipids extraction for Selenastrum Capricornutum biomass.

2014 International Renewable and Sustainable Energy Conference (IRSEC), 2014

This research shows the comparison of different techniques for harvesting of microalga Pavlova Lu... more This research shows the comparison of different techniques for harvesting of microalga Pavlova Lutheri. The chosen techniques are the most used; all of them are compared with the aim to chose the most effective for this microalga.

Environmental Progress & Sustainable Energy, 2015

ABSTRACT This research article describes and analyses the use of seaweeds residue as pellets. Pel... more ABSTRACT This research article describes and analyses the use of seaweeds residue as pellets. Pellets are 12 mm in diameter and 15 mm in length and were obtained from eight marine seaweeds collected from Galician beaches. Different parameters, such as moisture content, heating power, volatile matter, ash content, and fixed carbon, were determined to analyze the suitability of using these pellets in boilers. From the results, it can be concluded that the obtained pellets are not suitable for using directly in boilers. Moreover, the results suggest that the seaweeds pellets have similar properties than straw pellets. The classification based on obtained results after testing seaweeds residue as pellets is D12, A10.0+, and BD700+. © 2015 American Institute of Chemical Engineers Environ Prog, 2015

Formación universitaria, 2010

Se presenta una aplicación de las llamadas píldoras del conocimiento en el marco de las nuevas te... more Se presenta una aplicación de las llamadas píldoras del conocimiento en el marco de las nuevas tecnologías en la docencia universitaria, desarrolladas en la Universidad de Vigo, España. Se analiza el concepto de píldora del conocimiento y se presenta una sobre el tema de equilibrio químico de interés en Ingeniería Química y estudios afines. Las píldoras creadas tienen igual formato, y se basan en la definición de Polimedia, técnica muy valorada en desarrollos de nuevas tecnologías para la enseñanza ya que permite que el ponente interactúe con la presentación. El objetivo último de las píldoras y en particular de la discutida en este trabajo es mejorar el proceso de aprendizaje del alumno y facilitar la integración de las materias, todo esto en el marco del Espacio Europeo de Educación Superior. Se analiza finalmente la cantidad de accesos de dichas píldoras en el tiempo y se concluye sobre las ventajas de su uso como tecnología docente de apoyo a la enseñanza-aprendizaje.

International Journal of Engineering Pedagogy (iJEP), 2013

Chemical engineering laboratory practices based in mini-projects were design and applied the stud... more Chemical engineering laboratory practices based in mini-projects were design and applied the students of forestry engineering in chemical subject. This way of practice reveals a more cooperative learning and a different style of experimentation. The stated goal was to design practices that motivate students and to enable them to develop different skills, including cross teamwork and communication. This paper describes how these practices were developed and the advantages and disadvantages of using this methodology of teaching.

DYNA, 2014

Computer simulation is a first logical step before taking a project to physical construction besi... more Computer simulation is a first logical step before taking a project to physical construction beside it is a powerful tool in energy network design. Combined systems are used to improve availability for energy supplied by renewable systems. The main inconvenient of some renewable energy sources is their highly seasonal nature, with great variations over time that can impede their use as the basis for consumption and limits them to peak demand times. The aim of this work is to simulate to verify the energetic sufficiency of a family house with renewable energies (wind, solar-photovoltaic) using a hybrid system of batteries and hydrogen. For that, Simulink®-Matlab® program was used considering meteorological data provided by CINAM (Galician Center for Environmental Research and Information). The model can be applied to determine the feasibility of implementing an energy network in specific places, and to predict energy flows and system behavior throughout the year.

Journal of Chemical & Engineering Data, 2006

Density, viscosity, Excess molar Volume and viscosity deviation for [chloroform (1)+Methanol (3)]... more Density, viscosity, Excess molar Volume and viscosity deviation for [chloroform (1)+Methanol (3)] binary system and [chloroform (1)+Di-isopropylether (2)+Methanol (3)] ternary system at 298.15 K.

European Journal of Engineering Education, 2012

Reda Abdulaal Nidhal Abdulaziz Wisam Abu Jadayil James Abulencia Araceli Adam Olusola Adesope Ped... more Reda Abdulaal Nidhal Abdulaziz Wisam Abu Jadayil James Abulencia Araceli Adam Olusola Adesope Pedro Luis Aguado Alison Ahearn Aoife Ahern Tony Ahfock Ali Al-Bahi Firoz Alam Katariina Alha Esat Alpay Burkhard Alpers Anabela Alves José Jaílson Alves Catherine Amelink Jane Andrews Nana Kofi Annan Arif Anwar Alireza Asgari Giuliano Augusti Aris Avdelas Robert Ayres Barbara Bagilhole Balamuralithara Balakrishnan Moshe Barak Sarah Barnard Ricardo Barros Raphaël Bary Adnan Bashir Samuel Bassetto Ipshita Basu Hoda Baytiyeh Frank Becker Kacey Beddoes Robert Benavente Jens Bennedsen Ineke Berq Anders Berglund Enrique Berjano Jonte Bernhard Ragbir Bhathal Manpreet Bhatti Zhuming Bi Sylvio Bistafa Aaron Blicblau Wim Blokzijl Cyril Boateng Maartje Van Den Bogaard Steffen Bohrmann Alejandra Boni Jose Borges Maura Borrego Brian Bowe Lyn Brodie Erik Brogt Christian Byrge Edmond Byrne C.R. Rachana Angel Cámara Rascón

International Journal of Environmental Research, 2016

Wastewater contains many organic and inorganic contaminants that can cause serious damage to the ... more Wastewater contains many organic and inorganic contaminants that can cause serious damage to the environment and health of people, Therefore, they have to be eliminated before being downloaded into sensitive areas. Different methods of wastewater purification have been used for contaminants removal. However, they present some technical and economic limitations. Thus, new methods of nutrients removal by microalgae based on phytoremediation techniques, become promising methods due to its viability. The objective of wastewater treatment is to improve and purify the water. For that, the removal of all or some of the nutrients present in water is carried out, resulting in a reusable or suitable water to be returned to its natural environment. This study investigates the capacity of Chlorella Vulgaris microalga as a potential candidate for removing the phosphorous and organic matter from wastewater. The strain of microalga was cultivated in synthetic wastewater at room temperature with ar...

International Journal of Environmental Research, 2018

Soil contamination by hydrocarbons is an environmental problem and its remediation is necessary. ... more Soil contamination by hydrocarbons is an environmental problem and its remediation is necessary. This work presents the effect of ultrasound on solvent extraction of soil contaminated with diesel fuel. For the experiments, the soil was contaminated with diesel (10% wt.). The remediation was carried out by ultrasonic solvent extraction and compared with Soxhlet extraction. The effect of different parameters (time, temperature, soil/solvent ratio and type of solvent) on removal efficiency was examined. With the aim to optimize the ultrasonic extraction, a Box-Behnken design under response surface methodology was used and the proposed model showed a good fit of the experimental data. The obtained results were compared with a conventional solvent extraction (Soxhlet) for both solvents (n-hexane and acetone). Moreover, the phytotoxic effect of soil after remediation treatment was observed on seed germination of Brassica rapa. The obtained results demonstrated that hexane was more effective than acetone in removing hydrocarbons from contaminated soil (80%), and the removal efficiency increased with the soil/solvent ratio ([ 1:5) and reaction time ([ 90 min). A secondorder polynomial model was proposed to predict the removal efficiency of the extraction process.

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2016

ABSTRACT Biodiesel is renewable and environmental friendly, with calorific value equivalent to reg... more ABSTRACT Biodiesel is renewable and environmental friendly, with calorific value equivalent to regular fossil fuel. This fuel can be produced from a variety of feedstocks, such as first-generation biodiesel feedstock (corn, peanut, soybean), second generation (jatropha, animal fats, waste cooking oils, macroalgae), and third generation (microalgae). Among these feedstocks, biodiesel production from microalgae has drawn special attention for different reasons: they have high lipid content and high growth rates; they are tolerant to severe environmental conditions; they offer the possibility of sequester carbon dioxide from the flue gases; their harvesting and transportation are economical compared to other crops; and they have very high photosynthetic yields compared to other terrestrial plants. The advantage of using macroalgae recollected on the beaches as raw material is that allows to obtained energy from a residue. Microwave-assisted extraction and transesterification of microalgae is being researched as a solution for biodiesel production by its benefits, such as shorter reaction times and less amount of heat energy to obtain biodiesel. It is due to the fact that microwaves can easily penetrate through the cell wall structure to extract and transesterify the oils into biodiesel. The aim of this research was to explore the possibility of carrying out the microwave-assisted transesterification of three marine macroalgae (brown and green). Different experimental runs were carried out with different process parameters such as macroalgae-to-methanol ratio, reaction time and catalyst concentrations. Based on the obtained results, the best conditions for microwave-assisted transesterification reaction were macroalgae-to-methanol ratio of 1:15 (wt/vol), sodium hydroxide concentration of 2 wt% and reaction time of 3 min.

DYNA, 2015

This paper describes a vehicle simulation toolbox developed under Matlab® environment, which can ... more This paper describes a vehicle simulation toolbox developed under Matlab® environment, which can be used to estimate the range of a vehicle battery, or a fuel cell/battery hybrid system. The model is function of mechanical and physical variables that depend not only on the vehicle but also on the ground. This toolbox can be extended to GPS tracking files by means of reading data file plug-ins. Even standard drive cycles can be simulated. Battery and hydrogen consumption, hydrogen storage tank level, battery state of charge, power consumption and fuel cell energy production, maximum range and maximum number of cycles for a real route can be determined. The model facilitates the prediction of the vehicle range and the hydrogen and energy consumption. Real route simulation gives a good approximation of the vehicle speed close to real-life services instead of using driving cycles that are quite arbitrary approximations to a real route.

Chemical Engineering Transactions

Microalgae culture is a potential source of biodiesel and one of the best alternatives as raw mat... more Microalgae culture is a potential source of biodiesel and one of the best alternatives as raw material for biodiesel production. The first objective of this work is the pilot plant design for microalgae culture of high oil content species. The design was inspired by raceway large-scale culture. Although this kind of culture is usually in outdoor ponds, the pilot plant is an indoor raceway pond, therefore, it was necessary to design the lighting system and, also, the stirring system. The designed device was tested with Isochrysis Galbana clon T-Iso semi-continuous culture. Finally, microalgae oil was extracted and this oil was suitable for biodiesel production.

Chemical Engineering Transactions

Huge efforts have been carried out in recent years in order to develop an alternative fuel from r... more Huge efforts have been carried out in recent years in order to develop an alternative fuel from renewable resources, such as biodiesel fuel. Therefore, the use of cooking oil as raw material is a very interesting alternative for the production of biodiesel. In this work, waste frying oil was used as raw material for enzymatic biodiesel production. Moreover, this study analyzes the influences of the type of enzymatic catalyst on the conversion of methyl esters, as well as the influence of other variables such as reaction time.

European Journal of Sustainable Development, 2015

This paper presents a toolbox for the simulation of a zero emission urban hybrid bus, which combi... more This paper presents a toolbox for the simulation of a zero emission urban hybrid bus, which combines batteries and fuel cells. This type of vehicle performs predefined routes with a certain frequency, then they are an ideal option to the replacement of combustion engines with renewable energy systems. The simulation of these vehicles can be made for different standard driving cycles (ECE-15, EUDC, NEDC, SFUDS) or for real routes from GPS device data. This will allow to consider the orography of the route, considering the slope that overcomes the vehicle at each time, generally this parameter is not included in other models, and it could become a determining factor for the applicability of these vehicles on certain specified routes. Moreover, this tool lets to study and to analyse other not easily quantifiable factors, such as the weather or peak-hour traffic. Finally, the performance of an urban hybrid bus was investigated to assess its theoretical range and the technical feasibility of zero-emission vehicles.

European Journal of Sustainable Development, 2015

Hydrogen shows very interesting features for its use on-board applications as fuel cell vehicles.... more Hydrogen shows very interesting features for its use on-board applications as fuel cell vehicles. This paper presents the modelling of a tank with a metal hydride alloy for on-board applications, which provides good performance under ambient conditions. The metal hydride contained in the tank is Ti0.98Zr0.02V0.43Fe0.09Cr0.05Mn1.5. A two-dimensional model has been performed for the refuelling process (absorption) and the discharge process (desorption). For that, individual models of mass balance, energy balance, reaction kinetics and behaviour of hydrogen gas has been modelled. The model has been developed under Matlab / Simulink© environment. Finally, individual models have been integrated into a global model, and simulated under ambient conditions. With the aim to analyse the temperature influence on the state of charge and filling and emptying time, other simulations were performed at different temperatures. The obtained results allow to conclude that this alloy offers a good behaviour with the discharge process under normal ambient conditions.

European Journal of Sustainable Development, 2015

An increasing global demand for a biologically produced energy source has emerged due to the exha... more An increasing global demand for a biologically produced energy source has emerged due to the exhausted usage of non-renewable petroleum-derived fuels. Microalgae are a promising feedstock for biofuels because of their capability to produce lipids. In this paper, two operations for biodiesel production were studied from Phaeodactylum Tricornutum microalgae. This marine diatom shows a big potential to produce biodiesel due to its fast growth and lipid accumulation ability. In this research, first the microalgae was harvesting using an inorganic flocculant as copper (II) sulphate (CuSO4). When the dose was 200 mg/L, the microalgae recovery was close 83% in the first five minutes. After that, the microalgal oil was separated by ultrasound extraction process, using ethanol as solvent. This allows to analyze the oil content of the microalgae which is used later in the transesterification. The obtained lipid content was 38% wt. Temperature variations were observed in this process. Finally, a direct transesterification reaction took place with base catalysis by three ways: traditional, microwave assisted and ultrasound assisted. Direct transesterification microwave assisted achieved 52% conversion to biodiesel versus 16% for the traditional method. However, the best performance (90%) was obtained for ultrasound assisted transesterification.

European Journal of Sustainable Development, 2015

This study investigates the effect of ultrasounds in conversion of waste frying oil into biodiese... more This study investigates the effect of ultrasounds in conversion of waste frying oil into biodiesel. Many researchers have studied the use of ultrasounds in the biodiesel production from different feedstock; however, there are few studies focused on the biodiesel production from waste frying oil. In this research, ultrasound-assisted transesterification was carried out to convert the waste frying oil into biodiesel directly. The effect of different process parameters such as reaction time (30-90 min), amount of catalyst (0.5-1% wt. NaOH) and temperature (20-40 ºC) were also analyzed to obtain the higher conversion. A methanol to oil molar ratio of 6:1, 0.5% amount of catalyst and 30 ºC was enough to complete the process in 60 min. The obtained results in this study confirm that that ultrasound-assisted transesterification was a fast and efficient method for biodiesel production from waste frying oil even if reaction temperature is low.

European Journal of Sustainable Development, 2015

An alternative for biodiesel production is the use of lipids from microalgae. Although all steps ... more An alternative for biodiesel production is the use of lipids from microalgae. Although all steps to obtain this biofuel are important, harvesting and extraction are the most important. Advances in these areas are necessary in order to obtain third-generation fuels. The purpose of the present study is to compare different methods of lipids extraction and harvesting for freshwater Selenastrum Capricornutum microalgae. The method used for harvesting was flocculation with inorganic agent. Copper (II) Sulphate (CuSO4) was used as flocculant, resulting in the best percentage of recovery (76%) for a dose of 2 g/L. Previously oil extraction, the collected samples were homogenized and their moisture content was analysed obtaining values of 55-96%. Two extraction methods were used: Soxhlet and ultrasound. The use of ultrasound favours cell disruption and increases the extraction yield. In extraction methods, polar, non-polar solvents, and mixes of solvents were used. N-hexane and acetone were used as solvents for Soxhlet extraction, and ethanol, acetone, methanol, chloroform, and a mixture of chloroform and methanol in 1:2 and 2:1 ratios, for extraction ultrasound assisted method. The use of the methanol-assisted ultrasound is the most efficient method for lipids extraction for Selenastrum Capricornutum biomass.

2014 International Renewable and Sustainable Energy Conference (IRSEC), 2014

This research shows the comparison of different techniques for harvesting of microalga Pavlova Lu... more This research shows the comparison of different techniques for harvesting of microalga Pavlova Lutheri. The chosen techniques are the most used; all of them are compared with the aim to chose the most effective for this microalga.

Environmental Progress & Sustainable Energy, 2015

ABSTRACT This research article describes and analyses the use of seaweeds residue as pellets. Pel... more ABSTRACT This research article describes and analyses the use of seaweeds residue as pellets. Pellets are 12 mm in diameter and 15 mm in length and were obtained from eight marine seaweeds collected from Galician beaches. Different parameters, such as moisture content, heating power, volatile matter, ash content, and fixed carbon, were determined to analyze the suitability of using these pellets in boilers. From the results, it can be concluded that the obtained pellets are not suitable for using directly in boilers. Moreover, the results suggest that the seaweeds pellets have similar properties than straw pellets. The classification based on obtained results after testing seaweeds residue as pellets is D12, A10.0+, and BD700+. © 2015 American Institute of Chemical Engineers Environ Prog, 2015

Formación universitaria, 2010

Se presenta una aplicación de las llamadas píldoras del conocimiento en el marco de las nuevas te... more Se presenta una aplicación de las llamadas píldoras del conocimiento en el marco de las nuevas tecnologías en la docencia universitaria, desarrolladas en la Universidad de Vigo, España. Se analiza el concepto de píldora del conocimiento y se presenta una sobre el tema de equilibrio químico de interés en Ingeniería Química y estudios afines. Las píldoras creadas tienen igual formato, y se basan en la definición de Polimedia, técnica muy valorada en desarrollos de nuevas tecnologías para la enseñanza ya que permite que el ponente interactúe con la presentación. El objetivo último de las píldoras y en particular de la discutida en este trabajo es mejorar el proceso de aprendizaje del alumno y facilitar la integración de las materias, todo esto en el marco del Espacio Europeo de Educación Superior. Se analiza finalmente la cantidad de accesos de dichas píldoras en el tiempo y se concluye sobre las ventajas de su uso como tecnología docente de apoyo a la enseñanza-aprendizaje.

International Journal of Engineering Pedagogy (iJEP), 2013

Chemical engineering laboratory practices based in mini-projects were design and applied the stud... more Chemical engineering laboratory practices based in mini-projects were design and applied the students of forestry engineering in chemical subject. This way of practice reveals a more cooperative learning and a different style of experimentation. The stated goal was to design practices that motivate students and to enable them to develop different skills, including cross teamwork and communication. This paper describes how these practices were developed and the advantages and disadvantages of using this methodology of teaching.

DYNA, 2014

Computer simulation is a first logical step before taking a project to physical construction besi... more Computer simulation is a first logical step before taking a project to physical construction beside it is a powerful tool in energy network design. Combined systems are used to improve availability for energy supplied by renewable systems. The main inconvenient of some renewable energy sources is their highly seasonal nature, with great variations over time that can impede their use as the basis for consumption and limits them to peak demand times. The aim of this work is to simulate to verify the energetic sufficiency of a family house with renewable energies (wind, solar-photovoltaic) using a hybrid system of batteries and hydrogen. For that, Simulink®-Matlab® program was used considering meteorological data provided by CINAM (Galician Center for Environmental Research and Information). The model can be applied to determine the feasibility of implementing an energy network in specific places, and to predict energy flows and system behavior throughout the year.

Journal of Chemical & Engineering Data, 2006

Density, viscosity, Excess molar Volume and viscosity deviation for [chloroform (1)+Methanol (3)]... more Density, viscosity, Excess molar Volume and viscosity deviation for [chloroform (1)+Methanol (3)] binary system and [chloroform (1)+Di-isopropylether (2)+Methanol (3)] ternary system at 298.15 K.