Thermo-fluid dynamics modelling of steam electrolysis in fully-assembled tubular high-temperature proton-conducting cells

Electrolysis based on renewable energies offers a promising carbon-free solution for hydrogen generation and storage. The recent developments of proton ceramic electrolysis cells operating at intermediate temperatures bear promise of superior energy efficiency compared to oxide ion conducting electrolytes. Here, a proton ceramic Single Engineering Unit (SEU) design is optimized for steam electrolysis using a computational fluid dynamics (CFD) model implemented in a COMSOL Multiphysics software. The SEU is an all-in-one tubular cell arrangement that constitutes the smallest electrolysis unit and enables efficient, adaptable pressurized hydrogen generation. The parametrical modelling study is conducted for two adiabatic operation scenarios with distinct steam conversion rates and tested for multiple key parameters, namely internal and external chamber pressures and inlet stream temperature. The modelling results show that low steam conversions enable operation at higher current densities and that the thermoneutral voltage for a fixed steam conversion is highly sensitive to the process conditions and operation modes. The increment of the pressure of the generated hydrogen implies a reduced production rate at thermoneutral voltage, although it can be compensated with an enhanced steam pressure or a reduced inlet temperature. Additionally, the introduction of a porous medium as the SEU current collector in the steam chamber enhances heat transport within this chamber. The area specific resistance of the system determines the current density, enforcing an adaption of the area of the electrolyser to satisfy the target hydrogen production and energy efficiency. The resulting proposed SEU design and adapted operational parameters allow effective delivery of pressurized dry hydrogen for a wide range of conditions and applications.publishedVersio

Molecular understanding of the catalytic consequence of ketene intermediates under confinement

[Image: see text] Neutral ketene is a crucial intermediate during zeolite carbonylation reactions. In this work, the roles of ketene and its derivates (viz., acylium ion and surface acetyl) associated with direct C–C bond coupling during the carbonylation reaction have been theoretically investigated under realistic reaction conditions and further validated by synchrotron radiation X-ray diffraction (SR-XRD) and Fourier transformed infrared (FT-IR) studies. It has been demonstrated that the zeolite confinement effect has significant influence on the formation, stability, and further transformation of ketene. Thus, the evolution and the role of reactive and inhibitive intermediates depend strongly on the framework structure and pore architecture of the zeolite catalysts. Inside side pockets of mordenite (MOR), rapid protonation of ketene occurs to form a metastable acylium ion exclusively, which is favorable toward methyl acetate (MA) and acetic acid (AcOH) formation. By contrast, in 12MR channels of MOR, a relatively longer lifetime was observed for ketene, which tends to accelerate deactivation of zeolite due to coke formation by the dimerization of ketene and further dissociation to diene and alkyne. Thus, we resolve, for the first time, a long-standing debate regarding the genuine role of ketene in zeolite catalysis. It is a paradigm to demonstrate the confinement effect on the formation, fate, and catalytic consequence of the active intermediates in zeolite catalysis

Catalytic cracking performance of alkaline-treated zeolite Beta in the terms of acid sites properties and their accessibility

The zeolite Beta is considered as a promising additive for FCC catalyst in diesel oil production. In this article, it is shown that hierarchical zeolite Beta obtained by an optimized desilication procedure increases diesel and propylene yields during gas oil cracking reaction. The alkaline treatment of zeolite Beta (Si/Al = 22) by desilication with NaOH and NaOH&TBAOH was investigated. The catalytic performance improvement of desilicated zeolite Beta has been rationalized by deep characterization of the samples including X-ray diffraction, low-temperature adsorption of nitrogen, solid-state 29Si MAS NMR and IR studies of acidity. Finally, the catalytic performance of the zeolites Beta was evaluated in the cracking of n-decane, 1,3,5-tri-iso-propylbenzene, and vacuum gas oil. It was found that desilication with NaOH&TBAOH ensures the more uniform intracrystalline mesoporosity with the formation of narrower mesopores, while preserving full crystallinity resulting in catalysts with the most appropriated acidity and then with better catalytic performance.Also, M.C.I.L., J.M.T. and F.R. thank financial support from the Spanish Ministry of Economy and Competitiveness through the Severo Ochoa program (SEV-2012-0267) as well as operating grants Consolider Ingenio Multicat (CSD-2009-00050) and MAT-2012-3856-0O2-01.Tarach, K.; Gora-Marek, K.; Tekla, J.; Brylewska, K.; Datka, J.; Mlekodaj, K.; Makowski, W.... (2014). Catalytic cracking performance of alkaline-treated zeolite Beta in the terms of acid sites properties and their accessibility. Journal of Catalysis. 312:46-57. https://doi.org/10.1016/j.jcat.2014.01.009S465731

Quality of life of patients with type 2 diabetes in relation to method of treatment

Inappropriate glycaemic control in type 2 diabetes leads to long-term complication and affects length of life. Intensification of treatment, involving insulin therapy is often delayed because of fear of negative influence on quality of life (QoL). Aims: evaluation of differences on QoL with type 2 diabetes patients in relation to method of current antidiabetic treatment, especially patients who are on the threshold of insulin therapy introduction. Methods: study involved 274 patients (mean 62.2years, 55.8%F) who were divided into 3 groups: patients treated with oral anti-diabetic agents (OAD group, n=111), patients, for whom insulin was introduced (Intensification group, n=68) and patients treated with insulin (Insulin group, n=95). QoL was measured with questionnaires: EQ-5D, DQL-BCI and DSC-R. Results: There were no statistically significant differences in EQ-5D indices among studied patients (OAD group-0.82, Intensification group–0.78, Insulin group–0.75). EQ-VAS among patients switched to insulin therapy was lower than in OAD group (52.7 and 59.3, respectively, p=0.004). The differences in DQL-BCI scores among all groups of patients were statistically insignificant (scores: OAD group-56.7, Intensification group-54.8, Insulin group-51.7). DSC-R score in Intensification group was higher than among OAD group (30.9 and 25.3, respectively, p=0,08). Patients switched to insulin therapy manifested the highest level of hyperglycemia-related burden and the lowest treatment satisfaction. Conclusions: patients whose treatment was intensified reported their QoL as lower than the patients treated with OAD, however there was no significant difference found in respect of QoL between patients from the latter group and patients already treated with insulin

How to study migrant workers, precarious labour and community organisation in the north of Ireland : between sectarian communities and labour markets. Participative methodology (video and theatre)

This is an innovative participative long term action research project being carried out by an action research group on the initiative of migrant workers. The research group is known as the Migrant Action Research Project (MARP) and is sponsored by the Independent Workers’ Union, Strathclyde University and CAIRDE (an association of communities in Armagh City). The team (six nationalities) comprises; migrant workers, former migrant now long term settled workers, academics, union activists, youth and community workers and media workers in the north of Ireland and Scotland. The research utilises semi-structured interviews and focus groups and is conducted by the team who are subject-initiator-participants. This action research will be presented at a range of fora, inter alia, the Armagh and Belfast festivals and local migrant community events though the medium of video and theatre. Our project is based upon a democratic participative methodology deriving from Freire’s (1970) Education for critical consciousness and Boal’s (1979) Theatre of the Oppressed. In MARP’s research practices interviewer and interviewee are understood as action participant-subjects as opposed to objects of research. MARP goes beyond, while recognising the import of the academy and union recruitment, objectification of our participants. Research aims are: to present our agenda to increase shared knowledge with the goal of participant social change in work and the community; second, for the purposes of social and political change, to link together the relationships engendered between work, or non paid work, and community-worker organisation. In discussing of our methodology we present some of initial findings