Maria Alzira Pimenta Dinis

Review of European energy policies regarding the recent “carbon capture, utilization and storage” technologies scenario and the role of coal seams

Abstract European energy policy has made an effort in the last years in developing a coherent strategy towards the definition of a set of goals, involving the reduction in greenhouse gas emissions and, at the same time, increasing renewable energy use. This paper presents the different options of carbon capture, utilization and storage (CCUS) technologies regarding the legislative initiatives implemented in the new European energy policy. This new European energy strategy was established taking into consideration not only energy demand but also social and environmental requirements. Taking that into account, the different strategies adopted by the European energy council are discussed and an overview of carbon capture and storage (CCS) technologies—a mitigation strategy able to reduce greenhouse gas emissions—and the CO2 potential utilization were also addressed. Conventional and unconventional CO2 geological storage/sequestration reservoirs are analysed, taking into consideration the different properties of both types of reservoirs. Finally, it is possible to conclude that coal seams must play a major role in CCS/CCUS technologies, since coal is considered as an efficient technological solution to CO2 geological storage/sequestration.

Unconventional coal reservoir for CO2 safe geological sequestration

The energy dependency is one of the major problems the international community faces nowadays and governments are being encouraged to develop strategies in different fields in order to reduce their external dependency. Additionally, the European Commission sustainable energy plan is engaged into reducing greenhouse gases effect to promote sustainable environment. It is not yet possible to displace fossil fuels from the energy scenario and it is essential to apply new technologies, such as CCS (carbon, capture and storage) technologies, specifically CO2 geological storage/sequestration. The paper studies different coal samples (considered one of the solutions of CO2 geological storage/sequestration) concerning their storage and gas circulation capacities since they are highly dependent on coal physical/chemical properties which are intimately related to its genetic conditions and incarbonisation processes. Petrographic parameters are also studied, since they will induce different porous structures and inte...

Mid- and long-term anxiety levels associated with presymptomatic testing of Huntington’s disease, Machado-Joseph disease, and familial amyloid polyneuropathy

Objective: To study anxiety as a variable of the mid- and long-term psychological impact of pre-symptomatic testing for three autosomal dominant late-onset disorders – Huntington’s disease (HD), Machado-Joseph disease (MJD) and familial amyloid polyneuropathy (FAP) TTR V30M – in a Portuguese sample. Methods: This cross-sectional study included 203 participants: 170 (83.7%) underwent pre-symptomatic testing for FAP, 29 (14.3%) for HD, and 4 (2%) for MJD. Of the 203 participants, 73 (36.0%) were asymptomatic carriers, 29 (14.5%) were symptomatic carriers, 9 (4.5%) were diagnosed with FAP and had a liver transplant, and 89 (44.5%) were non-carriers. Most were women (58.1%) and married (66.5%). The anxiety variable was assessed using the Zung Self-Rating Anxiety Scale (SAS). Results: The anxiety scores were higher for symptomatic carriers and for those who underwent psychological support consultations over the years. For symptomatic carriers, the mean scores were superior to 40 points, which reflects clinical anxiety. Conclusion: Although it was not possible to differentiate between the mid- and long-term psychological impacts, this study supports the conclusion that the proximity to the age of symptoms onset might be a trigger for anxiety.

Subjects At-Risk for Genetic Diseases in Portugal: Illness Representations.

This study investigates illness representations of subjects at-risk for 3 autosomal dominant late-onset disorders: Familial Amyloid Polyneuropathy (FAP) TTR V30M, Huntington’s disease (HD) and Machado-Joseph disease (MJD), comparing them with the illness representations of subjects at-risk for Hemochromatosis (HH). The present study included a clinical group that consisted of 213 subjects at genetic risk (FAP, HD and MJD), comprising 174 subjects at-risk for FAP, 34 subjects at-risk for HD and only 5 subjects at-risk for MJD; and the control group consisting of 31 subjects at genetic risk for HH. All subjects at-risk were undergoing the process of genetic counseling to learn their genetic status (carrier or non-carrier). Subjects were assessed through a semi-structured single interview, in order to obtain sociodemographic data and the answer to an open-ended question relating to the illness representation issue: “What does this illness mean to you?/ What is this disease to you?” It was in the subjects’ metaphors that subjects best expressed what they felt regarding the disease and the situation of being at-risk for this disease. Family is their mirror and their source of learning and, therefore, it is inevitable that family is related to the meaning of the disease itself.

Gas content derivative data versus diffusion coefficient

The study of the gas diffusion process has a main role in both coalbed methane (CBM) production and CO2 injection in geological sequestration projects. The accurate determination of gas diffusion coefficients in unconventional reservoirs such as coal seams requires a consistent mathematical approach. The study of the gas diffusion process in coal seams was carried out using sorption isotherms. The Langmuir model for individual gases and the extended Langmuir model for multicomponent gas mixtures were applied to fit sorption isotherm data. “Gas content derivative data” and “gas content changes” emerged as crucial mathematical parameters to accurately study the gas diffusion process. The main goal of this paper is to define the degree of interaction between the gas content derivative data and the gas diffusion process. Experiments were performed on three samples selected from two different coals, which were submitted to three different gas compositions, viz 99.999% CH4; 99.999% CO2; and a gas mixture containing 74.99% CH4 + 19.99% CO2 + 5.02% N2, at 35℃, and at pressures ranging from 0 up to 50 bar. Experimental results obtained from the three samples indicate that during adsorption/desorption processes, the diffusion coefficients increase and the gas content changes decrease when the pressure decreases, due to the sample saturation degrees and to the kinetic mechanisms increase. Additionally, the “gas content derivative data” scattering is slightly lower during the desorption process than during the adsorption process. These behaviours are clearly identified when using methane, but are even more evident when using CO2 and the gas mixture, due to the CO2 interaction with coal porous structure, which induces a considerable resistance to CO2 release. The results show that sample B (CH4 + CO2 + N2) displays higher diffusion coefficient values (this behaviour is mainly related to the presence of N2) than sample C (CH4) and than sample A (CO2).

Depression as the middle-and long-term impact for pre-symptomatic testing of late-onset neurodegenerative disorders

This cross-sectional study investigated depression as the middle- (4 years) and long-term (7 and 10 years) psychological impact of pre-symptomatic testing (PST) for 3 autosomal dominant late-onset diseases: Huntington’s disease (HD), Machado-Joseph disease (MJD) and familial amyloidotic polyneuropathy (FAP) TTR V30M. It included 203 subjects: 170 (83.7%) underwent the PST for FAP, 29 (14.3%) for HD and 4 (2%) for MJD. Of these 203, 73 were still asymptomatic carriers, 29 (14.5%) were symptomatic, 9 (4.5%) were FAP liver transplanted patients and 89 (44.5%) were non-carriers. Subjects were mainly women (58.1%) and married (66.5%). The Beck Depression Inventory (BDI) was used to evaluate depression. Scores were higher for symptomatic carriers and for those who have made one or more psychological support consultations over the years. For the formers, the mean scores pointed to mild depression. Asymptomatic carriers and non-carriers had similar scores but it was impossible to differentiate the psychological impact between the medium and long-term. For symptomatic carriers, there

Coal gas adsorption/desorption isotherms versus diffusion process

In the present work, the authors studied two meta-anthracite samples from Douro coalfield (NW of Portugal) in which classical sorption isotherms were carried out, using CO2 only. Results have demonstrated that whenever the CO2 is adsorbed in the coal pores/matrix it will be enduringly fixed up to, approximately, pressures of 32 bar in sample A and 34 bar in sample B. Since the gas release process is intensely related to diffusion coefficients, it is crucial to define their evolution on the two analyses reported in this paper. So, during adsorption, diffusion coefficients decrease in sample A from 4.66736E-08 to 1.23490E-09 cm2/sec (6.72 and 48.13 bar) and during desorption they increase from 7.61829E-09 to 1.09908E-08 cm2/sec (45.68 and 11.48 bar). In sample B, diffusion coefficients decrease from 2.47409E-08 to 2.11813E-09 cm2/sec (7.53 and 47.17 bar) in adsorption and increase in desorption from 1.48767E-09 to 2.83736E-08 cm2/sec (42.22 and 7.71 bar).

Illness representations, knowledge and motivation to perform presymptomatic testing for late-onset genetic diseases

Abstract This study addresses the relation between illness representations, knowledge and motivation to perform the presymptomatic testing (PST) of subjects at-risk for Familial Amyloydotic Polyneuropathy (FAP), Huntington’s disease (HD) and Machado–Joseph disease (MJD), compared with subjects at-risk for Hereditary Hemochromatosis (HH). The sample comprised a clinical group of 213 subjects at genetic risk for FAP, HD and MJD, and a comparison group of 31 subjects at genetic risk for HH, that answered three open-ended questions relating illness representations, knowledge about the disease, and motivation to perform PST. People at-risk for FAP, HD and MJD use more metaphors, make more references to the family, are more concerned with the future and feel more out of curiosity and to learn, than for HH. These subjects at-risk correspond to the profile of somatic individual or personhood, wherein the unsubjectivation of the disease can function as a coping mechanism.

Gas diffusion coefficient in coal: calculation of tangent slope accuracy through the inflection point determination

This investigation aims to develop an accurate method to calculate the tangent slope (b) - a fundamental parameter to calculate gas diffusion coefficients under different pressures - using inflection point determinations. The authors also studied the different tangent slope behaviours depending on the experimental gas sorption used. The single Langmuir model for individual gases and the extended Langmuir model, for multicomponent gas mixtures were applied to fit experimental gas sorption isotherm data. Two coals were selected in order to minimize and/or avoid the maceral composition and vitrinite mean random reflectance effects. Samples were submitted to three different gas compositions, viz. 99.999% CH4; 99.999% CO2; and a gas mixture containing 74.99% CH4 + 19.99% CO2 + 5.02% N2. Results showed that the first and the second derivatives calculated to define the first inflection points represent exactly the final limit of tangent slopes.

Increasing Sorption Isotherms Accuracy: Weibull Modelling and Linear Regression

Relying on an adequate mathematical approach, two different mathematical procedures can be applied to the huge database produced during gas sorption isotherm experiments in order to obtain accurate data to be used in the industrial practice. To treat data determined from gas sorption isotherms without a careful mathematical support will produce inaccurate results, because all the determinations will be dependent on human decision. The minimum error reported since the first stage of a sorption isotherm determination, which corresponds to volume calibrations of reference and sample cells performed through the use of helium, will produce enormous inaccuracies on sorption isotherm behavior. These inaccurate behaviors may sometimes invalidate any Coalbed Methane recovery and CO2 injection programs. The study consisted on investigating gas sorption isotherm accuracies determined during the first part of the sorption process, which is mainly conducted by monitoring the pressure decline with time, in the reference and the sample cells (when both cells are not in contact), until the stabilization stage is achieved. Three samples from two different coals were selected in order to study their gas sorption behavior, in terms of a clear mathematical approach, when submitted to three different gas compositions, viz. 99.999% methane (CH4); 99.999% carbon dioxide (CO2); and a gas mixture containing 74.99% CH4 + 19.99% CO2 + 5.02% nitrogen (N2). Sorption experiments allow to conclude that the three samples present the same mathematical response during the first part of the sorption process. However, all gas sorption data (adsorption and desorption) collected from reference cell have a better fitting to a Modified Weibull Model, and all gas sorption data (adsorption and desorption) collected from sample cell respond in a trustworthy way to a Linear Regression Model. Confidence bands and prediction intervals (or bands) were also computed.