Experimental study of methane-oriented gasification of semi-anthracite and bituminous coals using oxygen and steam in the context of underground coal gasification (UCG): Effects of pressure, temperature, gasification reactant supply rates and coal rank

The results of ex-situ small-scale laboratory tests performed in a bespoke batch reactor simulating coal gasification to find the most optimal experimental conditions for producing methane-rich syngas in the context of UCG are presented in this paper. The influence of gaseous reactants (oxygen and steam), their supply rates and thermodynamic conditions (temperatures of 650 °C, 750 °C, 850 °C and pressures of 20 bar and 36 bar) on the gasification of semi-anthracite (South Wales coalfield) and bituminous (Silesian basin) coals is investigated. Increasing the gasification pressure from 20 bar to 36 bar and doubling the amount of steam with respect to oxygen benefit the methane generation. Although temperature increase from 650 °C to 850 °C also benefits methane generation, gasification at 750 °C provides the most optimal conditions for methane-rich syngas production. Overall, the highest methane generation occurs at 750 °C, 36 bar and H2O:O2 = 2:1 yielding peak methane concentrations of 44.00 vol% and 35.55 vol%, and average methane concentrations of 15.34 vol% and 14.64 vol% for the semi-anthracite and bituminous coals, respectively. These findings demonstrate that an increase in coal rank favours the methane generation. Owing to high methane content, the syngas produced at such conditions contains the highest calorific value, although the generation of hydrogen and carbon monoxide is reduced in comparison to the experiments conducted at 850 °C. This study shows that gasification of bituminous and semi-anthracitic coals at elevated pressures can provide stable generation of methane-rich syngas whose quality can be controlled by the gasification temperature through the dynamics of steam and O2 supply rates

A numerical modelling study to support design of an in-situ CO2 injection test facility using horizontal injection well in a shallow-depth coal seam

Previous projects on CO2 storage in coal often reported the challenges associated with coal swelling and swelling-induced loss of gas injectivity. Since coal seams are typically thin, commonly used vertical wells only intersect a target reservoir over a small contact area, placing constraints on CO2 injectivity in addition to those resulting from coal swelling. This leaves the storage reservoirs largely under-utilized and, therefore, questions the viability of this technology. To address the challenges/limitations of the current practice, a novel in-situ CO2 injection test is planned using horizontal injection wells in Mikolow, Poland. This paper presents the pre-operational simulation studies conducted to assist the design and operation of the in-situ test. An existing dual-porosity model that is built on a coupled thermo-hydro-chemical-mechanical (THCM) modelling framework is employed in this study. Sensitivity of the model parameters and validity of the model are tested. Several simulation scenarios are developed in reference to the selected test site for various horizontal well configurations and gas injection conditions. From the results and analyses, it is evident that by varying the coal-CO2 contact area via the length of the horizontal injection well, as well as the operating conditions including fixed pressure, and fixed rate injection scenarios, the targeted amount (between 1 to 10 tonnes) of CO2 can be injected into the seam without significant loss of permeability or injectivity, yielding sustained gas injection. Moreover, the spread of CO2 is predicted to be contained within the model domain suggesting no significant concern of spread exceeding the test area

Neonatal survival and kidney function after prenatal interventions for obstructive uropathies

Objectives: Prenatal interventions in LUTO (lower urinary tract obstruction) usually are still question of a debate between gynaecologist and paediatric nephrologist. We aimed the study to assess the early survival rate and renal outcome in LUTO foetuses. Material and methods: The study was a prospective data analysis of 39 foetuses from singleton pregnancies. All pregnant women with LUTO in the foetus were qualified for VAS based on a local practice. The mean time of first urine analysis ranged between 13–30 weeks of pregnancy. Primary end-point analysis included live birth, 28d-survival, pulmonary and renal function assessment in neonatal period. Results: From initial number of 39, six patients miscarried before the procedure was performed. Overall, 33 VAS were performer at the mean 21 week of pregnancy (range 14–30 weeks). 25/39 foetuses survived until delivery. Three neonates died in first 3 days of life. In the first month 3 children required peritoneal dialysis, but at 28 day all children were dialysis-free. Overall survival rate at 28 day was 56%. Renal function preservation of the initial group (39) turned out to be low — 18% (7/39). Conclusions: Our study showed average survival curves and complications. LUTO in the foetus had mostly unfavourable outcome in the neonatal period. The prenatal intervention did not increase it significantly and did not guarantee the preservation of normal kidney function

Diketopiperazine-Based, Flexible Tadalafil Analogues: Synthesis, Crystal Structures and Biological Activity Profile

Phosphodiesterase 5 (PDE5) is one of the most extensively studied phosphodiesterases that is highly specific for cyclic-GMP hydrolysis. PDE5 became a target for drug development based on its efficacy for treatment of erectile dysfunction. In the present study, we synthesized four novel analogues of the phosphodiesterase type 5 (PDE5) inhibitor—tadalafil, which differs in (i) ligand flexibility (rigid structure of tadalafil vs. conformational flexibility of newly synthesized compounds), (ii) stereochemistry associated with applied amino acid building blocks, and (iii) substitution with bromine atom in the piperonyl moiety. For both the intermediate and final compounds as well as for the parent molecule, we have established the crystal structures and performed a detailed analysis of their structural features. The initial screening of the cytotoxic effect on 16 different human cancer and non-cancer derived cell lines revealed that in most cases, the parent compound exhibited a stronger cytotoxic effect than new derivatives, except for two cell lines: HEK 293T (derived from a normal embryonic kidney, that expresses a mutant version of SV40 large T antigen) and MCF7 (breast adenocarcinoma). Two independent studies on the inhibition of PDE5 activity, based on both pure enzyme assay and modulation of the release of nitric oxide from platelets under the influence of tadalafil and its analogues revealed that, unlike a reference compound that showed strong PDE5 inhibitory activity, the newly obtained compounds did not have a noticeable effect on PDE5 activity in the range of concentrations tested. Finally, we performed an investigation of the toxicological effect of synthesized compounds on Caenorhabditis elegans in the highest applied concentration of 6a,b and 7a,b (160 μM) and did not find any effect that would suggest disturbance to the life cycle of Caenorhabditis elegans. The lack of toxicity observed in Caenorhabditis elegans and enhanced, strengthened selectivity and activity toward the MCF7 cell line made 7a,b good leading structures for further structure activity optimization and makes 7a,b a reasonable starting point for the search of new, selective cytotoxic agents

Receptor Modeling Source Apportionment of PM10 and Benzo(a)pyrene in Krakow, Poland

The main energy source in Krakow, Poland is coal combustion, which is believed to be the reason for frequent winter episodes of extremely high ambient air concentrations of particulate matter (PM10) and associated benzo(a)pyrene B(a)P. Results are presented on the source apportionment of PM10 and B(a)P during two episodes of thermal inversion (14/1 ; 2/3, 2005) at four different air monitoring stations and four apartments (indoor) in the city of Krakow, The results are compared to the Zakopane mountain site selected due to its prominent domestic coal heating and little traffic. The source apportionment was based on receptor modeling of the total of 72 ambient PM samples and 21 individual PM sources, chemically characterised for a high number of organic and inorganic compounds including polyaromatics (15 PAH and 18 azaarenes) heavy metals and trace elements (28 compounds), major ions, soot and organic carbon. An array of multivariate receptor models was used i.e. chemical mass balance (CMB), constrained matrix factorisation (CMF), constrained physical receptor modelling (COPREM) positive matrix factorization (PMF), principle component analysis with multi-linear regression analysis (PCA-MLRA), edge analysis (UNMIX), cluster analysis (CA), and self organizing maps SOM). The variation in the receptor dataset (55 compounds, 60 outdoor and 12 indoor PM samples) allowed the models of the pure factor analysis type (PMF, UNMIX, PCA-MLRA) to identify 3-5 factors of mixed sources. The interpretation of the factors was not straightforward, but pointed to a dominating primary source contribution from coal combustion (>60%) and a minor contribution from traffic (<10%). The secondary PM sources (20-30%) comprised industry and traffic. The results of cluster analysis and self organizing maps supported these indications. PMF was able to disaggregate the coal combustion into three factors i.e. ~10% related to industrial activities, ~20% related to home heating by stoves (coal) and ~30% related to boilers. The chemical fingerprints of the receptor samples and the main PM sources in Krakow and Zakopane allowed the pure chemical mass balance; type model (EPA-CMB8.2) to estimate the major contributions from two primary source types i.e. residential heating by coal combustion in small stoves and low efficiency boilers (~45%) and boilers with rudimentary PM reductions techniques such as cyclones (~15%), one major secondary source deriving from industrial and traffic emissions of SO2 + NOx + possibly HCl (~20%). Five minor primary sources were also identified i.e. traffic 5%, biomass burning ~5%, coke/fuel combustion ~5%, industrial high efficiency coal combustion 3%, and road/salt/rock re-suspension ~2%. The indoor PM10 and B(a)P were found to have the same sources as outdoor PM10 and B(a)P The results obtained by the models CMF and COPREM - which are hybrids of factor analysis and chemical mass balance generally agreed with the CMB results. However, their source contribution estimates are slightly different: residential heating ~30%, boilers with rudimentary PM reductions techniques such as cyclones ~30%, industrial high efficiency coal combustion ~15% traffic 3-7%, secondary 13-21%, road/salt/rock re-suspension 2-8%. All receptor models calculated residential heating to be the principal PM source in Zakopane (70-80%).JRC.H.4-Transport and air qualit

UCGWATER+: un proyecto europeo para el desarrollo de estrategias de descontaminación de aguas procedentes de la gasificación subterránea del carbón y otras actividades industriales

This project is funded by the Research Fund for Coal and Steel (RFCS) of the European Union (EU) under Grant Agreement No. 101033964.Peer reviewe

Hyperglycemia in pregnancy — prevalence and perinatal outcomes. A retrospective multicenter cohort study in Poland

Objectives: Hyperglycemia in pregnancy (HIP) is one of the most common complications of pregnancy. Recently adopted new criteria for the diagnosis of HIP as well as the greater prevalence of risk factors could have a significant impact on HIP prevalence. The objective of the study was to assess the rates of HIP and the associated complications. Material and methods: This was a retrospective analysis of clinical records from pregnant women who delivered in eight tertiary hospitals in Poland in 2016. Results: The number of pregnant women with hyperglycemia totaled 1280 (7.25%), including gestational diabetes mellitus (GDM) in 1169 (6.62%) women and pregestational diabetes mellitus (PGDM) in 111 (0.63%). In addition to dietary modifications, 477 (41% of the GDM group) women received medical treatment (GDMG2). In women with PGDM multiple daily insulin injections (MDI) were used in 53 (47.7%) cases, continuous subcutaneous insulin infusions (CSII) in 57 (51.3%) cases and one woman was treated with metformin. The rate of cesarean sections was 69.4% and 62.9% for PGDM and GDM, respectively. Large-for-gestational-age (LGA) infants accounted for 38% and 21% of births in the PGDM and GDM groups, respectively. Of note are high rates of hyperbilirubinemia in infants born to mothers treated with insulin (13.5% for PGDM and 14.4% for GDMG2) vs infants born to mothers with diet (GDMG1) (3.4%). Conclusions: In Poland, the prevalence of HIP has nearly doubled in the past twenty years. Even with appropriate management, HIP is a significant risk factor for a cesarean section delivery, bearing an LGA infant and adverse neonatal outcomes

Quantifying the impact of residential heating on the urban air quality in a typical European coal combustion region

The present investigation, carried out as a case study in a typical major city situated in a European coal combustion region (Krakow, Poland), aims at quantifying the impact on the urban air quality of residential heating by coal combustion in comparison with other potential pollution sources such as power plants, industry, and traffic. Emissions were measured for 20 major sources, including small stoves and boilers, and the particulate matter (PM) was analyzed for 52 individual compounds together with outdoor and indoor PM10 collected during typical winter pollution episodes. The data were analyzed using chemical mass balance modeling (CMB) and constrained positive matrix factorization (CMF) yielding source apportionments for PM10, B(a)P, and other regulated air pollutants namely Cd, Ni, As, and Pb. The results are potentially very useful for planning abatement strategies in all areas of the world, where coal combustion in small appliances is significant. During the studied pollution episodes in Krakow, European air quality limits were exceeded with up to a factor 8 for PM10 and up to a factor 200 for B(a)P. The levels of these air pollutants were accompanied by high concentrations of azaarenes, known markers for inefficient coal combustion. The major culprit for the extreme pollution levels was demonstrated to be residential heating by coal combustion in small stoves and boilers (>50% for PM10 and >90% B(a)P), whereas road transport (<10% for PM10 and <3% for B(a)P), and industry (4−15% for PM10 and <6% for B(a)P) played a lesser role. The indoor PM10 and B(a)P concentrations were at high levels similar to those of outdoor concentrations and were found to have the same sources as outdoors. The inorganic secondary aerosol component of PM10 amounted to around 30%, which for a large part may be attributed to the industrial emission of the precursors SO2 and NOx