Patrícia Baptista

Multivariate near infrared spectroscopy models for predicting the methyl esters content in biodiesel.

Biodiesel is the main alternative to fossil diesel. The key advantages of its use are the fact that it is a non-toxic renewable resource, which leads to lower emissions of polluting gases. European governments are targeting the incorporation of 20% of biofuels in the general fuels until 2020. Chemically, biodiesel is a mixture of fatty acid methyl esters, derived from vegetable oils or animal fats, which is usually produced by a transesterification reaction, where the oils/fats react with an alcohol, in the presence of a catalyst. The European Standard (EN 14214) establishes 25 parameters that have to be analysed to certify biodiesel quality and the analytical methods that should be used to determine those properties. This work reports the use of near infrared (NIR) spectroscopy to determine the esters content in biodiesel as well as the content in linolenic acid methyl esters (C18:3) in industrial and laboratory-scale biodiesel samples. Furthermore, calibration models for myristic (C14:0), palmitic (C16:0), stearic (C18:0), oleic (C18:1), linoleic (C18:2) acid methyl esters were also obtained. Principal component analysis was used for the qualitative analysis of the spectra, while partial least squares regression was used to develop the calibration models between analytical and spectral data. The results confirm that NIR spectroscopy, in combination with multivariate calibration, is a promising technique to assess the biodiesel quality control in both laboratory-scale and industrial scale samples.

Multivariate near infrared spectroscopy models for predicting the iodine value, CFPP, kinematic viscosity at 40 °C and density at 15 °C of biodiesel

Biodiesel is one of the main alternatives to fossil diesel. It is a non-toxic renewable resource, which leads to lower emissions of polluting gases. In fact, European governments are targeting the incorporation of 20% of biofuels in the fossil fuels until 2020. Chemically, biodiesel is a mixture of fatty acid methyl esters, derived from vegetable oils or animal fats, which is usually produced by a transesterification reaction, where the oils or fats react with an alcohol, in the presence of a catalyst. The European Standard (EN 14214) establishes 25 parameters that have to be analysed to certify biodiesel quality and the analytical methods that should be used to determine those properties. This work reports the use of near infrared (NIR) spectroscopy to determine some important biodiesel properties: the iodine value, the cold filter plugging point, the kinematic viscosity at 40 degrees C and the density at 15 degrees C. Principal component analysis was used to perform a qualitative analysis of the spectra and partial least squares regression to develop the calibration models between analytical and spectral data. The results support that NIR spectroscopy, in combination with multivariate calibration, is a promising technique applied to biodiesel quality control, in both laboratory and industrial-scale samples.

Monitoring biodiesel fuel quality by near infrared spectroscopy

Biodiesel is produced mainly by a transesterification reaction which involves the reaction of vegetable oils, animal fats or waste oils with an alcohol (such as methanol) in the presence of a catalyst (such as sodium hydroxide or methoxide). Since the presence of contaminants can cause severe engine problems, the assessment of the biodiesel quality is very important. This work reports the use of near infrared (NIR) spectroscopy to determine the content of water and methanol in industrial and laboratory-scale biodiesel samples. A qualitative analysis of the spectra by principal components analysis was carried out and partial least squares regression was used to develop calibration models between spectral and analytical data. The results indicate that the use of NIR spectroscopy, in combination with multivariate calibration, is a promising technique to assess the biodiesel quality in both laboratory-scale and industrial-scale samples.

Quantification of technical impacts and environmental benefits of electric vehicles integration on electricity grids

In this paper a typical electricity distribution network for a residential area in Portugal is used in order to assess the impact of integrating different levels of pure electric vehicles and plug-in hybrid vehicles in the grid and in pollutants emissions. First, the amount of vehicles that can be safely accommodated in the grid will be determined. Second, changes in pollutants emissions will be evaluated, by applying a vehicle full life cycle analysis.

Monitoring the quality of oils for biodiesel production using multivariate near infrared spectroscopy models

Biodiesel is a mixture of fatty acid methyl esters, derived from vegetable oils or animal fats, which is usually produced by a transesterification reaction, where the oils or fats react with an alcohol in the presence of a catalyst. The quality of the oils used for biodiesel production strongly influences the final properties of biodiesel, namely its compliance to the European Standard. This work reports the use of near infrared (NIR) spectroscopy in the quality control of several oil properties, such as the iodine value, the water content and the acid number but, more importantly, the weight–weight percentages (wt%) of soybean, palm and rapeseed oil in mixtures. Principal component analysis was used to perform a qualitative analysis of the spectra, whereas partial least squares regression allowed the development of calibration models between analytical reference data and NIR spectra. The calibration ranges were 60–126 g I2 100 g−1 for the iodine value, 478–2500 mg kg−1 for the water content and 0.13-6.56 mg KOH g−1 for the acid number, whereas the validation errors were around 3.1 g I2 100 g−1, 111 mg kg−1 and 0.22 mg KOH g−1, respectively. The results obtained show that NIR spectroscopy is a promising technique to carry out the quality control of the commonly used vegetable oils for biodiesel production, namely the quality assurance and authenticity. Furthermore, it is of great value to have a simple, fast and reliable method to identify the composition of an oil mixture and/or some of its quality parameters, prior to storage or upon admission of a new lot of oil.

Evaluation of low power electric vehicles in demanding urban conditions: An application to Lisbon

This research paper analyses the use of four electric vehicles, two motorcycles (EM) and two small low powered electric vehicles (EV) in an urban environment with demanding topography and driving profile. The vehicles were compared with conventional technologies using a methodology that was developed to estimate its drive cycle (EV-DC) as well as the corresponding energy consumption, in a life-cycle approach. This methodology uses real-world driving cycles as input performed with conventional vehicles, in this case, on representative routes in Lisbon, and estimates the impacts on the driving cycle considering that an electric vehicle was used. The deviation between the original and the estimated driving cycles for electric vehicles was quantified considering the power and speed limitations of the electric vehicles and the average speed and trip time impacts were quantified. The results indicate up to 13% longer trip time for the vehicles and up to 25% longer trip time for motorcycles, resulting of reductions in average trip speed of up to 11 and 20% respectively. In terms of fuel efficiency, the electric technologies considered may reduce the Tank-to-Wheel (TTW) energy consumption in average 10 times for the vehicles and 4 times for the motorcycles. However, the reductions in a Well-to-Wheel (WTW) approach are reduced to a 5 times reduction in energy consumption for vehicles and a 2 times reduction for motorcycles. In all, this methodology corresponds to an innovative way oThis research paper analyses the use of four electric vehicles, two motorcycles (EM) and two small low powered electric vehicles (EV) in an urban environment with demanding topography and driving profile. The vehicles were compared with conventional technologies using a methodology that was developed to estimate its drive cycle (EV-DC) as well as the corresponding energy consumption, in a life-cycle approach. This methodology uses real-world driving cycles as input performed with conventional vehicles, in this case, on representative routes in Lisbon, and estimates the impacts on the driving cycle considering that an electric vehicle was used. The deviation between the original and the estimated driving cycles for electric vehicles was quantified considering the power and speed limitations of the electric vehicles and the average speed and trip time impacts were quantified. The results indicate up to 13% longer trip time for the vehicles and up to 25% longer trip time for motorcycles, resulting of reductions in average trip speed of up to 11 and 20% respectively. In terms of fuel efficiency, the electric technologies considered may reduce the Tank-to-Wheel (TTW) energy consumption in average 10 times for the vehicles and 4 times for the motorcycles. However, the reductions in a Well-to-Wheel (WTW) approach are reduced to a 5 times reduction in energy consumption for vehicles and a 2 times reduction for motorcycles. In all, this methodology corresponds to an innovative way of understanding how low-powered electric technologies, both vehicles and motorcycles, would perform in specific applications to replace conventional technologies, both in terms of trips statistics and of energy and environmental performance.f understanding how low-powered electric technologies, both vehicles and motorcycles, would perform in specific applications to replace conventional technologies, both in terms of trips statistics and of energy and environmental performance.

The Cost and Effectiveness of Sustainable City Logistics Policies Using Small Electric Vehicles

Originality/value When considering the goal of promoting SEV as a sustainable city logistics policy, under a methodology focused on mobility, operational performance, and environmental externalities, the authors concluded (a) the replacement rate SEV:van is determinant to make a decision on whether or not to use SEVs replacing vans, (b) SEVs are economically competitive with conventional vans if the replacement rate is 1:1, (c) SEVs have a better performance at the street level rather than at the city level, (d) SEVs can be used with normal traffic as a niche of market (lower than 5%), and (e) SEVs benefits exist, but they are not significant enough to drive suppliers for their adoption.

Real-Time Feedback Impacts on Eco-Driving Behavior and Influential Variables in Fuel Consumption in a Lisbon Urban Bus Operator

The main purposes of this research were, in a first stage, to assess the impacts of real-time feedback on the driving behavior of bus drivers, considering vehicle age and type and drivers experience and, in a second stage, to identify the main influential variables in fuel consumption. Data was collected with an on-board device used by a Portuguese urban bus transport operator. Significant increases in the performance of undesirable events were observed without real-time feedback, followed by decreases with the restart of real-time feedback. Higher increases (between 6% and 170%) were observed when driving Mini vehicles in comparison with other bus types, particularly in extreme accelerations, excess rpm, extreme braking, and hard starts. Furthermore, a General Linear Model was applied to assess the most influential variables on fuel consumption. Vehicle type and age are the most influential variables on fuel consumption, with minibuses presenting higher increases when compared with standard buses. Increases up to 3% were observed leading to an extra 3769 liters of fuel consumed when feedback was not provided. Decreases in fuel consumption between 0.3% and 2% were observed with real-time feedback, avoiding the consumption of 4280 L of fuel. The results obtained in this paper provide bus companies with insightful information for the development of future operational strategies and training programs.

Car Sharing Systems as a Sustainable Transport Policy: A Case Study from Lisbon, Portugal

Originality/value Overall, the results obtained from this research work quantify the contribution of car sharing to sustainable transport and highlights the positive effects of promoting a technological shift. These facts reinforce the need for public policies to support the integration of car sharing within the city’s solutions to promote a more sustainable mobility. The successful deployment of car sharing systems can be influenced by policies targeting features such as allocation of parking, the fees and complementarity with public transport, signage and markings, and marketing of social and environmental benefits.

Engine cold start analysis using naturalistic driving data: City level impacts on local pollutants emissions and energy consumption

The analysis of vehicle cold start emissions has become an issue of utmost importance since the cold phase occurs mainly in urban context, where most of the population lives. In this sense, this research work analyzes and quantifies the impacts of cold start in urban context using naturalistic driving data. Furthermore, an assessment of the influence of ambient temperature on the percentage of time spent on cold start was also performed. Regarding the impacts of ambient temperature on cold start duration, a higher percentage of time spent on cold start was found for lower ambient temperatures (80% of the time for 0°C and ~50% for 29°C). Results showed that, during cold start, energy consumption is >110% higher than during hot conditions while emissions are up to 910% higher. Moreover, a higher increase on both energy consumption and emissions was found for gasoline vehicles than for diesel vehicles. When assessing the impacts on a city perspective, results revealed that the impacts of cold start increase for more local streets. The main finding of this study is to provide evidence that a higher increase on emissions occurs on more local streets, where most of the population lives. This kind of knowledge is of particular relevance to urban planners in order to perform an informed definition of public policies and regulations to be implemented in the future, to achieve a cleaner and healthier urban environment.