scholarly journals Biologická konverze energeticky bohatých plynů na biometan

Entecho ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 1-9
Author(s):  
Eva-Žofie Hlinková ◽  
Zdeněk Varga ◽  
Jana Zábranská
Keyword(s):  
Carbon Dioxide ◽  
Energy Production ◽  
Anaerobic Fermentation ◽  
Ex Situ ◽  
Direct Introduction ◽  
Pilot Model ◽  
In Situ Method ◽  
Global Increase ◽  
Laboratory Models

Přechod ze stávajících neobnovitelných zdrojů elektrické energie na zdroje obnovitelné se jeví jako vhodné řešení pro celosvětově narůstající spotřebu energie. Udržitelná technologie pro zpracování organických odpadů formou anaerobní fermentace produkuje bioplyn, z kterého se odstraněním oxidu uhličitého získává biometan – energeticky bohatý plyn kompatibilní se zemním plynem a využitelný jako biopalivo. Zaváděním externího vodíku, získaného z přebytečné energie z obnovitelných zdrojů, do procesu anaerobní fermentace dochází pomocí hydrogenotrofních metanogenů k redukci oxidu uhličitého na metan, čímž se zvyšuje výhřevnost bioplynu v ideálním případě až na biometan. V rámci této práce byla zkoumána technologie obohacování bioplynu pomocí vodíku přímým zaváděním do fermentoru tzv. metoda in-situ a s využitím externího bioreaktoru tzv. metoda ex-situ Získané výsledky z provozu laboratorních modelů insitu a ex-situ bioreaktoru poslouží k sestrojení poloprovozního modelu této technologie pro následné převedení do praxe. Abstract - EN The transition from existing sources of electricity to renewables seems to be a suitable solution for the global increase of energy consumption. Sustainable technology of anaerobic fermentation for the treatment of organic wastes produces biogas, from which is by removing carbon dioxide obtained biomethane – energy-rich gas compatible with natural gas and can be used as biofuel. Hydrogen obtained by using excess energy production from renewable sources, can be introduce into the anaerobic fermentation process. Hydrogenotrophic methanogens use external hydrogen for reduction of carbon dioxide to methane, which increases energetical potencial of biogas, ideally up to the level of biomethane. In this work, the technology of enrichment of biogas with hydrogen by direct introduction into the fermenter, the “in-situ” method and with the use of an external bioreactor, the “ex-situ method,” was investigated. The results obtained from the operation of laboratory models of insitu and ex-situ bioreactors will be used to build a pilot model of this technology for subsequent implementation in practice.

In situ FT-IR and ex situ EPR analysis for the study of the electroreduction of carbon dioxide in N,N-dimethylformamide on a gold interface

2005 ◽  
Vol 578 (1) ◽  
pp. 87-94 ◽  
Author(s):  
Eduardo R. Pérez ◽  
Jarem R. Garcia ◽  
Daniel R. Cardoso ◽  
Bruce R. McGarvey ◽  
Elisete A. Batista ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ex Situ ◽  
Ft Ir

scholarly journals Validation of a method for in situ determination of 137Cs soil contamination density in kitchen gardens using the portable spectrometer-dosimeter MKS AT6101D

2021 ◽  
Vol 14 (2) ◽  
pp. 56-65
Author(s):  
V. P. Ramzaev ◽  
A. N. Barkovsky ◽  
A. A. Bratilova
Keyword(s):  
Soil Contamination ◽  
Chernobyl Accident ◽  
Soil Layer ◽  
Soil Samples ◽  
Ex Situ ◽  
Measuring Device ◽  
Kitchen Garden ◽  
In Situ Method ◽  
Kitchen Gardens

The collection of representative soil samples in the territory of settlements and subsequent measurements of the content of radionuclides in these samples under laboratory conditions (the so-called “ex situ method”) is a generally accepted technology for determining the density of soil contamination with 137Cs in the populated areas contaminated due to the Chernobyl accident. Recently, as a supplement or alternative to the ex situ method, researchers are developing field (in situ) gamma-spectrometry methods. These methods allow determining the density of soil contamination with 137Cs directly on site, without soil sampling and laboratory analysis. At the same time, the in situ methodology has several limitations, the most important of which is a lack of generally recognized metrological basis for measurements and interpretation of results. Hence, before using a particular technique and measuring device for carrying out large-scale in situ measurements, it is necessary to validate (to assess the suitability) of the selected in situ method using an established ex situ method. The aim of this study was to validate the method for determining the density of 137Cs soil contamination in kitchen gardens using the MKS AT6101D spectrometer-dosimeter in situ. The method was recently presented by a Russian-Swedish-Belarusian group of researchers in an article published in the Journal of Environmental Radioactivity (https://doi.org/10.1016/j.jenvrad.2021.106562). To validate this method, we selected 10 representative kitchen garden plots. The plots were located in six settlements of the Bryansk region in Russia. The territory of the settlements had been heavily contaminated with 137Cs as a result of the Chernobyl accident: the officially established levels of the density of soil contamination by 137Cs ranged from 111 to 511 kBq/m2 in 2017. Field gamma-ray spectra were recorded at a height of 1 m above the ground in the center of kitchen garden plots using the MKS AT6101D device. The measurement duration was in the range of 1207–1801 s (the mean value = 1383 s). Samples of soil in the kitchen gardens were taken layer by layer (with a step of 5 cm) to a depth of 20 cm using a demountable cylindrical sampler. The 137Cs content in each soil layer was determined in the laboratory using a stationary semiconductor gamma spectrometer. The values of the 137Cs contamination density of the sampled soils ranged from 77 to 548 kBq/m2. It was found that the results of the ex situ analyzes of soil samples were in a good agreement with the contamination density values obtained with the in situ method. On average, the difference between two methodologies was 7% (a maximum of 20%). The results of the study confirm that the method proposed by the international group is suitable for determining the density of soil contamination by 137Cs in kitchen gardens in remote period after the Chernobyl accident.

Zirconia incorporated calcium looping absorbents with superior sintering resistance for carbon dioxide capture from in situ or ex situ processes

2018 ◽  
Vol 2 (12) ◽  
pp. 2733-2741 ◽  
Author(s):  
Ming Zhao ◽  
Xu He ◽  
Guozhao Ji ◽  
Yinqiang Song ◽  
Xiao Zhao
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Capture ◽  
Ex Situ ◽  
Calcium Looping ◽  
Sintering Resistance

Zirconia incorporation greatly enhances the sintering resistance of CaO.

Advances in in situ and ex situ tar reforming with biochar catalysts for clean energy production

2018 ◽  
Vol 2 (2) ◽  
pp. 326-344 ◽  
Author(s):  
Yafei Shen ◽  
Yuhong Fu
Keyword(s):  
Energy Production ◽  
Clean Energy ◽  
Heterogeneous Reactions ◽  
Ex Situ ◽  
Homogeneous And Heterogeneous Reactions ◽  
Biomass Tar ◽  
Tar Reforming

Homogeneous and heterogeneous reactions can occur in the process of in situ or ex situ biomass tar reforming with biochar catalysts.

Crystallographic Features and Subband Transitions of Al/InAs Metal-Semiconductor Junctions

2000 ◽  
Vol 6 (S2) ◽  
pp. 1092-1093
Author(s):  
J.P. Zhang ◽  
S. Tsujino ◽  
M. Thomas ◽  
S.J. Allen
Keyword(s):  
Quantum Wells ◽  
Molecular Beam ◽  
Ex Situ ◽  
List Type ◽  
Aluminum Layer ◽  
Cross Sectional ◽  
Fee Structure ◽  
In Situ Method ◽  
Semiconductor Junction

To study the nature of metal-semiconductor junction, metal-clad InAs quantum wells with aluminum deposited on 15-nm thick InAs grown on (100) GaAs with AlSb barrier were prepared by an in-situ method (aluminum was grown immediately by molecular beam epitaxy) and by an ex-situ method (aluminum was deposited after exposing InAs surface in ambient condition by selective etching). Cross sectional TEM studies indicated that the Al grains in the clad aluminum layer were randomly arranged in the ex-situ grown junctions, while, in the in-situ samples, the aluminum grains were found to be well oriented to the underlying InAs.When the interface is viewed along [Oil], three observed crystallographic relationships for in-situ Al growth are1.[011]AI // [011]InAs and (100)AI // (100)InAs as shown in Fig. 1(a): the aluminum grains of facecentered cubic (fee) structure are perfectly aligned with the fee InAs lattice when they grow;

scholarly journals Bionanocellulose/Poly(Vinyl Alcohol) Composites Produced by In-Situ Method and Ex-Situ/Impregnation or Sterilization Methods

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6340
Author(s):  
Aldona Długa ◽  
Jolanta Kowalonek ◽  
Halina Kaczmarek
Keyword(s):  
Vinyl Alcohol ◽  
Gravimetric Method ◽  
Tensile Tests ◽  
Absorption Capacity ◽  
Ex Situ ◽  
Degree Of Crystallinity ◽  
Poly Vinyl Alcohol ◽  
Angle Measurements ◽  
In Situ Method

The purpose of the work was to obtain composites based on bionanocellulose (BNC) and poly(vinyl alcohol) (PVA) for specific biomedical and cosmetic applications and to determine how the method and conditions of their preparation affect their utility properties. Three different ways of manufacturing these composites (in-situ method and ex-situ methods combined with sterilization or impregnation) were presented. The structure and morphology of BNC/PVA composites were studied by ATR-FTIR spectroscopy and scanning microscopy (SEM, AFM). Surface properties were tested by contact angle measurements. The degree of crystallinity of the BNC fibrils was determined by means of the XRD method. The mechanical properties of the BNC/PVA films were examined using tensile tests and via the determination of their bursting strength. The water uptake of the obtained materials was determined through the gravimetric method. The results showed that PVA added to the nutrient medium caused an increase in biosynthesis yield. Moreover, an increase in base weight was observed in composites of all types due to the presence of PVA. The ex-situ composites revealed excellent water absorption capacity. The in-situ composites appeared to be the most durable and elastic materials.

Coloration of bacterial cellulose using in situ and ex situ methods

2018 ◽  
Vol 89 (7) ◽  
pp. 1297-1310 ◽  
Author(s):  
Euijin Shim ◽  
Hye Rim Kim
Keyword(s):  
Surface Roughness ◽  
Bacterial Cellulose ◽  
Carbon Sources ◽  
Production Yield ◽  
Ex Situ ◽  
Surface Appearance ◽  
Force Microscopy ◽  
Atomic Force ◽  
In Situ Method

This study aimed to produce colored bacterial cellulose (BC) by adding dye during cultivation (in situ) and by dyeing BC after cultivation (ex situ), respectively. Three different dyestuffs—direct, acid and reactive—were selected for application in the coloring of BC. In the in situ method, the dyestuff is adding into the culture medium. The effects of various dyestuff and carbon sources on the production yield were evaluated. In the ex situ method, the dyestuff, BC gel, was dyed under various dyestuff and dyeing conditions. The production yield of BC cultured by the in situ method in glucose as the carbon source and using a reactive dyestuff was the highest, at about 86%. The ex situ dyeability of BC was improved by setting the dyeing conditions to pH 3 and 135℃. Both methods were evaluated regarding the surface appearance of the BC by scanning electron microscopy (SEM). The SEM showed that the defined cellulose fibril networks retained their inherent nanostructures when the dye penetrated the site through dyeing. The surface roughness of the BC, colored by the two methods, was evaluated by atomic force microscopy. The BC colored by both methods showed smooth surfaces. For BC colored by the in situ method, the surface roughness was 194 nm, indicating that the BC was smoother and finer than that obtained via the ex situ method. In comparing hue and saturation values, the BC colored by the in situ method showed clearer blue colors than that colored by the ex situ method. The in situ method was more effective than the ex situ method for coloring BC.

Reactivity of supercritical sulfur dioxide and carbon dioxide in a carbonate reservoir: An experimental investigation of supercritical fluid-brine-rock interactions relevant to the Madison Limestone of Southwest Wyoming

2017 ◽  
Vol 5 (4) ◽  
pp. SS43-SS58 ◽  
Author(s):  
Curtis Chopping ◽  
John P. Kaszuba
Keyword(s):  
Carbon Dioxide ◽  
Sulfur Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Carbonate Reservoir ◽  
Ex Situ ◽  
Successful Implementation ◽  
Natural Analog ◽  
Madison Limestone ◽  
Supercritical Carbon

Managing impure carbon dioxide produced by fossil fuel-based generation of electricity is required for successful implementation of carbon capture, utilization, and storage. Impurities in carbon dioxide, particularly [Formula: see text] and [Formula: see text], are geochemically more reactive than the carbon dioxide and may adversely impact a carbon dioxide storage reservoir by generating additional acidity. Hydrothermal experiments are performed to evaluate geochemical and mineralogic effects of injecting [Formula: see text]-[Formula: see text] fluid into a carbonate reservoir. The experimental design is based on a natural carbon dioxide reservoir, the Madison Limestone on the Moxa Arch of Southwest Wyoming, which serves as a natural analog for geologic cosequestration of sulfur dioxide and carbon dioxide. Idealized Madison Limestone ([Formula: see text]) and [Formula: see text] brine ([Formula: see text], initial [Formula: see text]) reacted at reservoir conditions (110°C and 25 MPa) for approximately 165 days (3960 h). Carbon dioxide fluid containing 500 ppmv sulfur dioxide was injected and the experiment continued for approximately 55 days (1326 h). Sulfur dioxide partitions out of the supercritical carbon dioxide phase and dissolves into coexisting brine on the time scale of the experiments (55 days). Injecting supercritical [Formula: see text]-[Formula: see text] or pure supercritical carbon dioxide into a brine-limestone system produces the same in situ pH (4.6) and ex situ pH (6.4–6.5), as measured 28 h after injection because dissolution of calcite buffers in situ pH. Precipitation of anhydrite sequesters injected sulfur and, coupled with dissolution of calcite, effectively buffers the amount of dissolved calcium to the same concentrations measured in limestone-brine experiments injected with pure carbon dioxide. Supercritical [Formula: see text]-[Formula: see text] does not enhance the sequestration potential of a carbonate reservoir relative to pure supercritical carbon dioxide. Our results substantiate predictions from natural analog studies of the Madison Limestone that anhydrite traps sulfur and carbonate minerals ultimately reprecipitate and mineralize carbon in carbonate reservoirs.

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