Comparative assessment of gasification based coal power plants with various CO2 capture technologies producing electricity and hydrogen

Seven different types of gasification-based coal conversion processes for producing mainly electricity and in some cases hydrogen (H2), with and without carbon dioxide (CO2) capture, were compared on a consistent basis through simulation studies. The flowsheet for each process was developed in a chemical process simulation tool “Aspen Plus”. The pressure swing adsorption (PSA), physical absorption (Selexol), and chemical looping combustion (CLC) technologies were separately analyzed for processes with CO2 capture. The performances of the above three capture technologies were compared with respect to energetic and exergetic efficiencies, and the level of CO2 emission. The effect of air separation unit (ASU) and gas turbine (GT) integration on the power output of all the CO2 capture cases is assessed. Sensitivity analysis was carried out for the CLC process (electricity-only case) to examine the effect of temperature and water-cooling of the air reactor on the overall efficiency of the process. The results show that, when only electricity production in considered, the case using CLC technology has an electrical efficiency 1.3% and 2.3% higher than the PSA and Selexol based cases, respectively. The CLC based process achieves an overall CO2 capture efficiency of 99.9% in contrast to 89.9% for PSA and 93.5% for Selexol based processes. The overall efficiency of the CLC case for combined electricity and H2 production is marginally higher (by 0.3%) than Selexol and lower (by 0.6%) than PSA cases. The integration between the ASU and GT units benefits all three technologies in terms of electrical efficiency. Furthermore, our results suggest that it is favorable to operate the air reactor of the CLC process at higher temperatures with excess air supply in order to achieve higher power efficiency

Intimate Partner Violence: perspective of convicts and psychologists of penitentiary institutions. A Qualitative analysis with focus groups

Intimate Partner Violence is a complex process in which individual, relational and contextual variables intervene. The aim of this study was to explore coping strategies and relational dynamics in conflict situations involving people convicted of intimate partner violence with their partners. Focus groups were conducted with convicted intimate partner violence offenders (12 participants) and with psychology professionals (4 participants). The data were explored through thematic analysis following the Nested Ecological Model. The group of convicted perpetrators showed roles of authority and superiority over the woman, a feeling of vulnerability and rejection of the existing legal framework, fear of being arrested for wanting to continue the relationship, the need to control the partner driven by jealousy, justification or denial of responsibility in violent situations or instrumentalization of the children in common. The professionals point out cultural aspects that facilitate violent patterns and roles in the couple's dynamics, communication problems, denial or low awareness of the crime, among other issues. The results are of special interest both for professionals who wish to learn or deepen their knowledge on the subject, as well as for those who work in intervention and/or prevention of intimate partner violence.n. La violencia de género es un proceso complejo en el cual intervienen variables individuales, relacionales y contextuales. El presente estudio tiene como objetivo explorar las estrategias de afrontamiento y dinámicas relacionales en situaciones conflictivas en condenados por violencia de género con sus parejas. Se realizaron grupos focales con condenados por violencia de género (12 participantes) y con profesionales de la psicología (4 participantes). Los datos se exploraron mediante análisis temático siguiendo el Modelo Ecológico Anidado. El grupo de condenados muestra roles de autoridad y superioridad sobre la mujer, sensación de vulnerabilidad y rechazo ante el marco jurídico existente, miedo a sufrir arrestos por querer continuar con la relación, la necesidad de control de la pareja impulsada por lo celos, la justificación o negación de responsabilidad en las situaciones violentas o instrumentalización de los hijos/as en común. Los profesionales señalan aspectos culturales que facilitan esquemas y roles violentos en la dinámica de pareja, problemas de comunicación, negación o baja conciencia del delito, entre otros temas. Los resultados son de especial interés tanto para los profesionales que deseen conocer o profundizar en la temática, como para quienes trabajen en la intervención y/o prevención en violencia de género

Process simulation coupled with LCA for the evaluation of liquid - liquid extraction processes of phenol from aqueous streams

The steel industry is currently a major water pollution source, releasing high quantities of chemicals. One of the pollutants is phenol, known for its toxicity even when it is present in low concentrations. Liquid-liquid extraction employing various aromatics and cycloalkanes (i.e., benzene, toluene, cyclohexane, ethylbenzene) and ketones (i.e., methyl isobutyl ketone, cyclohexanone and mesityl oxide) as solvents, is studied in the present paper. A comparison among the seven solvents is performed based on process modelling simulation tools and Life Cycle Assessment (LCA). The simulations of the seven cases under study are conducted at the same wastewater flowrate of 100 tons/h, with a phenol content of 0.2 wt.% and compared using various parameters (i.e., quantity of solvent, steam and power used, quantity of solvent present in the output phenol streams). The simulation results show that the lowest quantity of solvent is registered in the phenol removal which uses cyclohexanone as solvent (e.g., 34,212.40 kg/h), followed by the case which uses mesityl oxide for the liquid-liquid extraction (e.g., 34,759.80 kg/h) and by the case involving cyclohexanone (e.g., 37,490.60 kg/h). The lowest steam consumption is registered also in the case of cyclohexanone usage (e.g., 47.56 GJ/h) while the lowest power consumption corresponds to mesityl oxide usage (e.g., 11.20 MJ/h). The simulation results are then used to perform an environmental analysis, quantified in terms of environmental key performance indicators, embedding several solvents production methods as well as various fuels. Our life cycle assessment leads to the conclusions that the most environmentally friendly design is phenol removal using cyclohexanone as a solvent, whose provision comes from cyclohexane, which in turn is produced from benzene in conjunction with steam production from natural gas. For instance, the lowest global warming potential indicator score is about 342 kg CO2 equivalents per kg of phenol, while the same indicator for the worst solvent, i.e., toluene produced using reforming technology and steam being produced using hard coal as fuel, is almost double (e.g., 341.94 kg CO2 equivalents per kg of phenol vs. 575.30 CO2 equivalents per kg of phenol). Lower values for other impact indicators are also obtained in the phenol removal using cyclohexanone as a solvent with steam being generated form natural gas (e.g., acidification potential indicator is 0.42 kg SO2 equivalents per kg of phenol, eutrophication potential is 4.21 7 10 122 kg PO43- equivalents per kg phenol, ozone depletion potential is 1.13 7 10-9 kg R11 equivalents per kg phenol)

Dosimetric study of electrophysiological recording devices based on micro-electrodes under Radio-Frequency exposures

International audienc

In vivo setup characterization for pulsed electromagnetic field exposure at 3 GHz

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