Low temperature regeneration of activated carbons using microwaves: Revising conventional wisdom

[EN] The purpose of this work was to explore the application of microwaves for the low temperature regeneration of activated carbons saturated with a pharmaceutical compound (promethazine). Contrary to expectations, microwave-assisted regeneration did not lead to better results than those obtained under conventional electric heating. At low temperatures the regeneration was incomplete either under microwave and conventional heating, being this attributed to the insufficient input energy. At mild temperatures, a fall in the adsorption capacity upon cycling was obtained in both devices, although this was much more pronounced for the microwave. These results contrast with previous studies on the benefits of microwaves for the regeneration of carbon materials. The fall in the adsorption capacity after regeneration was due to the thermal cracking of the adsorbed molecules inside the carbon porous network, although this effect applies to both devices. When microwaves are used, along with the thermal heating of the carbon bed, a fraction of the microwave energy seemed to be directly used in the decomposition of promethazine through the excitation of the molecular bonds by microwaves (microwave-lysis). These results point out that the nature of the adsorbate and its ability to interact with microwave are key factors that control the application of microwaves for regeneration of exhausted activated carbons.EÇ thanks The Council of Higher Education of Turkey (YÖK) for supporting her stay at INCAR (Oviedo) and the financial support of Istanbul University Research Fund (Project 3991) for her PhD thesis. JMB acknowledges CSIC for a JAE predoctoral fellowship. COA thanks the financial support of the projects CTM2008-01956 and CSIC-200980I131.Peer reviewe

Energy consumption estimation in the scaling-up of microwave heating processes

The specific energy consumption of six different microwave-driven processes and equipments has been studied and it was found that the scale used dramatically affects it. Increasing the amount of sample employed from 5 to 100 g leads to a reduction in the specific energy consumption of 90–95%. When the amount of sample is 200 g or higher, the specific energy consumption remains practically constant. This means that to assess the real energy efficiency of a microwave-driven process a minimum mass of about 200 g needs to be used. The energy results can then be easily extrapolated to larger scales. Otherwise, a correlation should be used to avoid overestimated energy values and inaccurate energy efficiencies.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 311815 (SYNPOL project). D.B. and N.R.R. are also grateful to FICYT of the Government of Principado de Asturias (Spain) and the Ministry of Economy and Competitiveness of Spain (under Project MAT2011-23733), respectively, for their predoctoral research grants. The help of Xerolutions S.L. in providing experimental data is also acknowledged.Peer reviewe

Microwave heating processes involving carbon materials

[EN] Carbon materials are, in general, very good absorbents of microwaves, i.e., they are easily heated by microwave radiation. This characteristic allows them to be transformed by microwave heating, giving rise to new carbons with tailored properties, to be used as microwave receptors, in order to heat other materials indirectly, or to act as a catalyst and microwave receptor in different heterogeneous reactions. In recent years, the number of processes that combine the use of carbons and microwave heating instead of other methods based on conventional heating has increased. In this paper some of the microwave-assisted processes in which carbon materials are produced, transformed or used in thermal treatments (generally, as microwave absorbers and catalysts) are reviewed and the main achievements of this technique are compared with those obtained by means of conventional (non microwave-assisted) methods in similar conditions.B.F., Y.F and L.Z. are grateful to CSIC of Spain and the European Social Fund (ESF) for financial support under thesis grant I3P-BDP-2006. Financial support from the PCTI-Asturias (Project PEST08-03) is also acknowledgedPeer reviewe

Cancer-associated fibroblasts modify lung cancer metabolism involving ROS and TGF-β signaling

Lung cancer is a major public health problem due to its high incidence and mortality rate. The altered metabolism in lung cancer is key for the diagnosis and has implications on both, the prognosis and the response to treatments. Although Cancer-associated fibroblasts (CAFs) are one of the major components of the tumor microenvironment, little is known about their role in lung cancer metabolism. We studied tumor biopsies from a cohort of 12 stage IIIA lung adenocarcinoma patients and saw a positive correlation between the grade of fibrosis and the glycolysis phenotype (Low PGC-1α and High GAPDH/MT-CO1 ratio mRNA levels). These results were confirmed and extended to other metabolism-related genes through the in silico data analysis from 73 stage IIIA lung adenocarcinoma patients available in TCGA. Interestingly, these relationships are not observed with the CAFs marker α-SMA in both cohorts. To characterize the mechanism, in vitro co-culture studies were carried out using two NSCLC cell lines (A549 and H1299 cells) and two different fibroblast cell lines. Our results confirm that a metabolic reprogramming involving ROS and TGF-β signaling occurs in lung cancer cells and fibroblasts independently of α-SMA induction. Under co-culture conditions, Cancer-Associated fibroblasts increase their glycolytic ability. On the other hand, tumor cells increase their mitochondrial function. Moreover, the differential capability among tumor cells to induce this metabolic shift and also the role of the basal fibroblasts Oxphos Phosphorylation (OXPHOS) function modifying this phenomenon could have implications on both, the diagnosis and prognosis of patients. Further knowledge in the mechanism involved may allow the development of new therapies.Work in the authors’ laboratories is supported by ‘‘Instituto de Salud Carlos III’’ PI13/01806 and PIE14/0064 to M.P. A.C-B, received a Spanish Lung Cancer Group fellowship. R.L-B, is supported by Comunidad Autónoma de Madrid “Garantía juvenil” contract

Cisplatin resistance involves a metabolic reprogramming through ROS and PGC-1α in NSCLC which can be overcome by OXPHOS inhibition

Background: Platinum-based chemotherapy remains the standard of care for most lung cancer cases. However chemoresistance is often developed during the treatment, limiting clinical utility of this drug. Recently, the ability of tumor cells to adapt their metabolism has been associated to resistance to therapies. In this study, we first described the metabolic reprogramming of Non-Small Cell Lung Cancer (NSCLC) in response to cisplatin treatment. Methods: Cisplatin-resistant versions of the A549, H1299, and H460 cell lines were generated by continuous drug exposure. The long-term metabolic changes, as well as, the early response to cisplatin treatment were analyzed in both, parental and cisplatin-resistant cell lines. In addition, four Patient-derived xenograft models treated with cisplatin along with paired pre- and post-treatment biopsies from patients were studied. Furthermore, metabolic targeting of these changes in cell lines was performed downregulating PGC-1α expression through siRNA or using OXPHOS inhibitors (metformin and rotenone). Results: Two out of three cisplatin-resistant cell lines showed a stable increase in mitochondrial function, PGC1-α and mitochondrial mass with reduced glycolisis, that did not affect the cell cycle. This phenomenon was confirmed in vivo. Post-treatment NSCLC tumors showed an increase in mitochondrial mass, PGC-1α and a decrease in the GAPDH/MT-CO1 ratio. In addition, we demonstrated how a ROS-mediated metabolism reprogramming, involving PGC-1α and increased mitochondrial mass, is induced during short-time cisplatin exposure. Moreover, we tested how cells with increased PGC-1a induced by ZLN005 treatment, showed reduced cisplatin-driven apoptosis. Remarkably, the long-term metabolic changes, as well as the metabolic reprogramming during short-time cisplatin exposure can be exploited as an Achilles’ heel of NSCLC cells, as demonstrated by the increased sensitivity to PGC-1α interference or OXPHOS inhibition using metformin or rotenone. Conclusion: These results describe a new cisplatin resistance mechanism in NSCLC based on a metabolic reprogramming that is therapeutically exploitable through PGC-1α downregulation or OXPHOS inhibitors.Work in the authors’ laboratories is supported by ‘‘Instituto de Salud Carlos III’’ PI13/01806 and PIE14/0064 to M.P. A.C-B, received a Spanish Lung Cancer Group fellowship. R.L-B, is supported by Comunidad Autónoma de Madrid “Garantía juvenil” contrac

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation

RICORS2040 : The need for collaborative research in chronic kidney disease

Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is 'solved' by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020-2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true

Reciclado de CO2 mediante reformado de gas de coquería para la producción de metanol

Tesis doctoral presentada en el Departamento de Ingerniería Química y Tecnología del Medio Ambiente de la Universidad de Oviedo. Mayo de 2013[EN] The steelmaking industry is the largest energy-consuming manufacturing sector. As a consequence of this, the CO2 emissions from this sector account for about 5-7 % of the total anthropogenic CO2 emissions. For this reason, increasing efforts are being made to find solutions that might help diminish these emissions and increase energy efficiency. A better management of the coke oven gas (COG) surplus is one of the proposed solutions. This study deals with the CO2 reforming of COG surplus. By means of this technology it is possible to obtain a synthesis gas with a composition suitable for use in the production of methanol. Thus, a highly valuable product, with many applications in different industries is obtained from two residual streams: the surplus of coke oven gas and CO2. Examined from a more global perspective this process constitutes a partial recycling of CO2, since part of the CO2 emitted when methanol is used is consumed in the production process. It has been established that, from the thermodynamic point of view, the most favourable operating conditions for carrying out the CO2 reforming of COG are temperatures higher than 800 ºC and the lowest possible pressures. In addition, the CH4/CO2 ratio must be as near to the stoichiometric ratio as possible. Otherwise, the process yield will be very low and/or the syngas thus obtained will not be suitable for methanol production. Since the CO2 reforming of methane is a heterogeneous catalytic reaction, it is necessary to use an appropriate catalyst. Several catalysts were tested, and the physical mixtures of activated carbon and a conventional Ni/Al2O3 catalyst were found to be the most promising. Such mixtures have a synergetic effect that leads to higher conversions of methane and carbon dioxide than those predicted by the law of mixtures. Moreover, the production of by-products, such us water, are lower than what is predicted by this law. It was found that the CO2 reforming of COG can take place via two different reaction mechanisms: on the one hand, the classical dry reforming, consisting of methane decomposition followed by gasification of the carbon deposits and on the other hand, due to the large amount of H2 present in the feed, the reverse Water Gas Shift followed by steam reforming. This latter reaction path appears to be the main mechanism, which would result in a lower deactivation rate than that of dry reforming. An assessment of the whole process, from the coke oven gas to the use of the methanol produced, has shown that this novel technology has certain advantages over conventional methanol production, the most important being lower CO2 emissions. Indeed, these emissions can be reduced by as much as 30%, depending on the location of the plant and the energy integration of the process. Moreover, COG-based production allows the maximum exploitation of the raw materials while purification costs are kept down to a minimum. From the energy point of view, COG-based production entails lower energy consumption than conventional production, whereas conventional production allows a higher energy recovery, which could eventually result in lower energy requirements provided that an adequate energetic integration strategy is adopted.[ES] La industria siderúrgica es el sector productivo con mayor consumo energético en el mundo. Debido a esto, sus emisiones de CO2 suponen entre el 5 y el 7% de las emisiones totales de origen humano. Por este motivo se está trabajando en la búsqueda de soluciones que permitan disminuir esas emisiones, así como mejorar la eficiencia energética. Una de esas soluciones es la mejora en la gestión y el aprovechamiento de los excedentes de gas de coquería. El reformado con CO2 de los excedentes de gas de coquería, que se estudia en este trabajo, puede suponer una salida rentable para esos gases, ya que permitiría la obtención de un gas de síntesis con una composición adecuada para la producción de metanol. Esto implicaría obtener un producto muy valioso a partir de dos corrientes gaseosas residuales: el propio excedente de gas de coquería y el CO2. De hecho, realizando un balance global al proceso, éste puede dar lugar a un reciclado parcial del CO2, ya que parte del CO2 que se produce tras la utilización del metanol se consume en la producción. Un estudio termodinámico del proceso de reformado con CO2 de gas de coquería permitió determinar que es necesario trabajar a temperaturas superiores a 800 ºC y a presiones tan bajas como la economía del proceso permita. Además, la relación de CH4/CO2 alimentada debe ser lo más próxima posible a la estequiométrica. En otras condiciones el rendimiento del proceso sería muy bajo y/o el gas de síntesis obtenido no tendría la composición adecuada para la producción de metanol. El reformado de metano con CO2 es una reacción catalítica heterogénea, por lo que es necesario encontrar catalizadores adecuados para llevarla a cabo. Se han evaluado diferentes catalizadores, siendo la mezcla física de carbón activo y un catalizador convencional Ni/Al2O3 la que ha dado lugar a resultados más prometedores. Esto se debe a que esta mezcla presenta un efecto sinérgico que permite alcanzar conversiones mayores a las que predice la ley de las mezclas y producciones de subproductos (en concreto agua) menores a las predichas por dicha ley. Asimismo, se ha determinado que la reacción puede tener lugar a través de dos posibles mecanismos. Por un lado, la vía clásica del reformado seco, formada por la descomposición de metano seguida de la gasificación de los depósitos de carbono. Por el otro, debido a la elevada proporción de H2 presente en la alimentación, se produciría la reacción inversa de la Water Gas Shift seguida del reformado con vapor de agua. Esta segunda vía parece ser la principal, lo que permitiría disminuir el elevado grado de desactivación de los catalizadores que tiene lugar en el reformado seco. Analizando el proceso completo, la producción de metanol a partir de gas de coquería presenta varias ventajas con respecto a la producción convencional. La mayor ventaja es la disminución de las emisiones de CO2 que, dependiendo de la localización geográfica de la planta, puede alcanzar hasta el 30 % de reducción. Además, este proceso permite maximizar el aprovechamiento de las materias primas y minimizar los costes de purificación. Desde el punto de vista energético, los consumos son menores, aunque la producción convencional permite mayores recuperaciones de energía, lo que puede dar lugar a menores necesidades energéticas si se realiza una correcta integración energética del proceso.Peer reviewe

Syngas from CO2 Reforming of Coke Oven Gas: synergetic effect of activated carbon / Ni-γAl2O3 Catalyst

[EN] The CO2 reforming of coke oven gas for the production of synthesis gas has been studied over an activated carbon, an in-lab prepared Ni/Al2O3 catalyst and physical mixtures of both materials in different proportions (AC + Ni) at 800 °C. It was found that there are two possible coexisting reaction pathways: the direct dry reforming of methane (decomposition of methane followed by gasification of the carbon deposits) and the reverse water gas shift reaction followed by the steam reforming of methane. If the process is carried out with the physical mixtures AC + Ni, there is a synergetic effect between both materials. The experimental conversions are higher than the conversions predicted by the law of mixtures, whereas the production of water is lower, resulting in a higher selectivity. The mixtures also showed a lower loss of porosity than when the activated carbon and the in-lab prepared Ni/Al2O3 were used individually. Therefore, the combination of these materials may produce catalysts that are more resistant to deactivation. The synthesis gas obtained was analyzed and it was found suitable for the production of methanol.JMB acknowledges the support received from the CSIC JAE Programmes. Financial support from the PCTI-Asturias (Project PEST08-03) is also acknowledged.Peer reviewe