Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Ograniczanie wyników
Czasopisma help
Lata help
Autorzy help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 716

Liczba wyników na stronie
first rewind previous Strona / 36 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  carbon dioxide
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 36 next fast forward last
1
Content available remote Czy da się skutecznie walczyć z CO2?
100%
PL
W niniejszym artykule przedstawiono informacje dotyczące reakcji konwersji ditlenku węgla z wodorem, prowadzącej do otrzymania węglowodorów. Na podstawie danych literaturowych oraz obliczeń własnych przeprowadzono analizę termodynamiczną procesu. Ponadto, przedstawiono postulowane w literaturze ścieżki reakcji; odnosząc się zarówno do właściwości użytego katalizatora oraz składu reagentów, jak i do warunków procesowych. Uwzględniono również wpływ użytego reaktora na przebieg procesu (m.in. reaktor fluidalny, autoklaw oraz reaktor ze stacjonarnym złożem katalizatora).
EN
In the paper, the actual knowledge in reaction of hydrocarbons synthesis from carbon dioxide and hydrogen was presented. The thermodynamic analysis was discussed on the basis of available literature data and own calculations. Moreover, postulated in the literature reaction mechanisms were discussed in the light of the catalysts properties and reactants composition, as well as the process conditions. The influence of the reactors type (fluidal, slurry and fixed bed) on the reaction course was also considered.
EN
The present work aims at prospective use of industrially available PebaxTM resin breathable films (Arkema) as membranes for CO2 separation from flue gas. The time-lag permeation and the microgravimetric techniques were used for the determination of the diffusion, sorption and permeation through PebaxTM 1074, 6100, 1657 and 3000 extruded films. The results indicate that the whole series of PebaxTM films is highly permeable to CO2 with the best value for the 6100 member, with a permeability coefficient of 100 barrers. In comparison with other polymer materials, the higher PebaxTM permeability to CO2 is due to higher values of both the sorption and the diffusion coefficients.
EN
With the International Energy Agency (IEA) projecting that the global demand for natural gas to increase by 50% from 2010 to 2035, the exploration of unconventional gas reserves (e.g. shale gas, tight gas and coal bed methane) will gain increasing importance as conventional gas reserves become more depleted. To enhance the production of unconventional gas and oil, water-based fracturing fluids are extensively used for the stimulation of North American shale plays because they are inexpensive and offer excellent proppant transport into the fracture when used with gelled polymers. However, in circumstances where water-based fracturing fluids are unsuitable due to concerns related to water sensitivity and clay swelling, alternative fracturing fluids are used such as nitrogen and carbon dioxide treatments. Nitrogen and carbon dioxide fracturing fluids are particularly advantageous in depleted and shallow formations because they offer a non-damaging effect around the fracture, rapid cleanup of flowback fluid, and reduced water requirements compared to conventional water-based fracturing fluids. Much research has been published about water-based fracture treatments, therefore, this review paper considers the use of nitrogen and carbon dioxide fracturing fluids used for the stimulation of unconventional shale plays, mainly in North America. By analysing selected literatures studies, this review paper summarises the utilization of the various types of nitrogen and carbon dioxide treatments (i.e. straight gas, foam, energized, cryogenic liquids) across various shale plays such as the Montney play, the Devonian play, and the Marcellus play. The paper further identifies the major benefits and challenges of nitrogen and carbon dioxide treatments documented by well operators, which will facilitate knowledge transfer about the applicability of nitrogen and carbon dioxide fracturing fluids.
EN
The aim of the research was to determine the exchange rate of carbon dioxide between the atmosphere and the maize field fertilized with the digestate from an agricultural biogas plant. The studies considered both the amount of net carbon dioxide emission which is the difference between the amount of this gas absorbed by vegetation and its amount emitted from the whole ecosystem of the field as well as the emission resulting only from the changes occurring in the soil. The CO2 emission from the entire field was measured by the eddy covariance method with a set of LI-7500A analyzer (LI-COR Biosciences, USA) for measuring the CO2/H2O concentration in air and 3-axis WindMaster ultrasonic anemometer (GILL, UK). The data from the analyzers were recorded at 10 Hz, while the CO2 streams were calculated using the EddyPro 5 software. The soil emission was determined with the chamber method using the automated ACE measurement system (ADC BioScientific, UK). Until the maize reached maturity, the study was carried out once a week, at 10.00 – 14.00. During each measurement day, the basic meteorological parameters were measured as well. The obtained results showed a clear relationship between the plants development phase and the size of the net CO2 exchange. The negative values of carbon dioxide streams, indicating the absorption of this gas from the atmosphere, were observed already in the case of plants with a height of approx. 25 cm, while the maximum values were reached after the release of panicles by maize. The carbon dioxide emission from soils, measured at the same time, was maintained throughout the entire research period at a similar low level, undergoing only slight fluctuations associated with variable soil moisture. The study showed that the maize field, almost throughout all growing season, can be treated as a sink of atmospheric carbon dioxide, reducing its emission from agriculture.
PL
Badania zostały przeprowadzone na terenie stacji badawczej "Ochrony środowiska i wpływów antropogenicznych na wody podziemne" w kwietniu i wrześniu 2000 r., w czasie trzydobowych próbnych pompowań studni ujmujących poziom czwartorzędowy i oligoceński. W artykule przedstawiono wyniki badań zawartości wybranych gazów: tlenu i dwutlenku węgla na tle analiz chemicznych wody. Z badań wynika, iż po wymianie objętości wody w rurach, w wodzie poziomu czwartorzędowego są niskie zawartości tlenu, zaś w oligoceńskim ­ zerowe. Wartości potencjału utleniająco­redukcyjnego pomimo nieznacznego wzrostu w czasie trwania pomiarów, wskazywała na warunki redukcyjne. Oznaczone były następujące formy dwutlenku węgla: wolny, węglanowy, wodorowęglanowy i agresywny. Największy udział stanowił wodorowęglanowy CO2, zaś węglanowego nie stwierdzono. Pośrednie wartości przypadały na wolny dwutlenek węgla, który wykazywał tendencję wzrostu wraz z upływem czasu trwania pompowania, co wiązało się jednocześnie ze zmianą odczynu wód. Analityczne badania wskazują ponadto na niewielkie zawartości agresywnego dwutlenku węgla, który pojawił się na III stopniu pompowania. Słowa kluczowe: tlen rozpuszczony, dwutlenek węgla, wody podziemne, poziom wodonośny czwartorzędowy, poziom wodonośny oligoceński, pompowanie badawcze.
EN
The study was conducted at the Scientific Station for Environmental Protection and Studies of Anthropogenic Impacts on Groundwaters, located next to the Faculty of Geology, the University of Warsaw (in Warsaw). The groundwaters from two monitoring wells supplied by Quaternary and Oligocene aquifers were examined during 3-day pumping tests. The results of the chemical composition of groundwaters and the content of dissolved oxygen and carbon dioxide are presented. The water derived from the Quaternary aquifer belongs to HCO3-SO4-Cl-Ca chemical class, whereas that from Oligocene aquifer-to HCO3-Cl-Na-Ca chemical class. A considerable amount of dissolved oxygen was found out only at the beginning of pumping tests. The following species of carbon dioxide were examined: hydrocarbonate, carbonate, free and aggressive C02. The distribution of free, hydrocarbonate and carbonate CO2 appears to be a function of the pH values. AtpHof 7, approximately 95% of total dissolved CO2 is represented by hydrocarbonate ions, whereas only 5% seems to bee free carbon dioxide. The saturation index for calcite has also been calculated using the computer program PCWAT-4. Its value was estimated at-1,223 for water derived from Quaternary aquifer and at -0,513 for water from Oligocene aquifer.
EN
The Carpathians may play a significant role as a supplier of greenhouse gases to the atmosphere. Unfortunately, most of the discovered oil and gas deposits are recently only historical objects. An example is the Sękowa-Ropica Górna-Siary oil deposit located in the marginal part of the Magura Nappe where oil had been extracted in dug wells until the mid XX century. One of such extraction sites is the “Pusty Las” oilfield. In that area, 10 methane and carbon dioxide emission measurement sites were located, among which 4 in dried dug wells and 6 in dig wells still filled with oil and/or water. Dynamics of methane and carbon dioxide concentration changes were measured with the modified static chambers method. Gas samples were collected immediately after the installation of the chamber and again, after 5 and 10 minutes. In the case of reclaimed or dry dug wells, static chamber was installed directly at the ground surface. In wells still filled with oil and/or water the chamber was equipped with an “apron” mounted on special sticks. The dynamics of concentrations changes varied from -0.871 to 119.924 ppm∙min-1 for methane and from -0.005 to 0.053% obj∙min-1 for carbon dioxide. Average methane emission was 1.9 g∙m-2∙d-1 and that of carbon dioxide was 26.95 g∙-2∙d-1. The measurements revealed that an abandoned oil field supplies significant amounts of greenhouse gases to the atmosphere although the emission of methane is lower than that measured e.g. in mud volcanoes located in various parts of the world.
EN
The summary of the measurements of CO2 stable isotopic composition emitted from different anthropogenic sources in the Krakow region is presented. The sources are divided into three main groups . high emission (electric and heat power plants), low emission (coal and methane burning in the households) and car traffic (gasoline, diesel and LPG supplied engines equipped and not equipped with catalyst). Presented results include two measurement campaigns made in the years 1995 and 2000. The measurements revealed three well-defined groups with respect to carbon isotope composition (delta13CVPDB): .30.60 plus-minus sign 0.37 per mille (thousand) sign (car traffic) .23.82 plus-minus sign 0.10 per mille (thousand) sign (coal burning) and .51.8 plus-minus sign 1.1per mille (thousand) sign (methane burning). The oxygen isotope composition (delta18OVPDB-CO2) of CO2 varied in a broad range, from ca. .11per mille (thousand) sign to ca. .22 per mille (thousand) sign, the most negative values being observed for coal and methane burning and the most positive for cars equipped with a catalyst. No significant isotopic shift has been observed between two measurement campaigns.
9
80%
EN
The problem of methane existence in coal beds has been known for many years. It was and still it is a danger to coalminers. The aim of the research, presented in the paper, is to show and assess the porosity structure (especially micro and nanoporosity) in accordance to the dimensions of carbon dioxide particle. The characteristic surface morphology of the sample and the disclosure of the carbon porous structure have been obtained using the scanning electron microscope (SEM). The presented study of the coal microstructure is a part of the coal demethanation method with the use of liquid CO2, that has been proposed by the Military University of Technology.
EN
The paper presents application of commercial sorbents, e.g. zeolites for capture of carbon dioxide from flue gases for low parameters of adsorption process. The main focus of the investigations was to minimize energy demand, therefore adsorption was carried out under low feed gas pressure. The applied gas mixture simulated the one emitted during coal burning in oxygen-enriched atmosphere, which is characterized by higher content of carbon dioxide in comparison with conventional burning. Variety of parameters which affect separation process such as step configuration, purge gas flow rate, adsorption time, and also temperature were taken into account during pressure swing adsorption.
PL
Badano zastosowanie komercyjnych sorbentów . zeolitów do wychwytywania dwutlenku węgla z gazów spalinowych. Głównym celem badań była minimalizacja zapotrzebowania energii, dlatego adsorpcję prowadzono pod niskim ciśnieniem gazu zasilającego. Zastosowana mieszanina gazów odpowiada składem gazom emitowanym podczas spalania węgla w atmosferze wzbogaconej tlenem. Charakteryzuje się ona większą zawartością dwutlenku węgla w porównaniu ze składem gazów w konwencjonalnym procesie spalania. W badaniach procesu adsorpcji zmiennociśnieniowej uwzględniono wiele parametrów, od których zależy separacja, takich jak: konfiguracja etapów, strumień gazu płuczącego, czas adsorpcji, a także temperatura.
EN
The lab-scale experiments were carried out in order to determine the effectiveness of CO2 capture from gases in the sodium hydroxide solutions under approximately standard conditions. The flow rate of the carrier gas was 140 l/min, and the CO2 content was 15%.The absorber was Dreschel washer with NaOH solution. The efficiency of CO2 capture of 85% was obtained for 50% of NaOH. It was proved that the increase of temperature in NaOH solution improves CO2 capture efficiency. The efficiency of capturing CO2 in 1 mol/l sodium carbonate was defined as 4–5%. The products of CO2 reactions in sorption solutions were marked.
PL
Dzięki sztucznym sieciom neuronowym możliwie jest rozwiązywanie specyficznych problemów, z którymi zmagają się tradycyjne techniki obliczeniowe. Sieci neuronowe mogą być stosowane tam, gdzie występują problemy z przetwarzaniem i analizą danych, ich przewidywaniem, klasyfikacją i kontrolą. Podjęte badanie wskazują, które czynniki sektora rolnego krajów Organizacji Współpracy Gospodarczej i Rozwoju (OECD) są powiązane z emisjami dwutlenu wegla. Badania oparto na analizie wariancji ANOVA z wykorzystaniem pakietu statystycznego R. Ewentualne spodziewane emisje dwutlenku węgla prognozowano z wykorzystaniem sieci neuronowych (SSN) Flexible Bayesian Models on Neural Networks. Prognozy umożliwiły identyfikację czynników szczególnie istotnych. Badanie wykazały znaczący wpływ na wielkość emisji dwutlenu wegla wielkości areałów pastwisk oraz gruntów ornych i stałych powierzchni upraw.
EN
The present-day emissions of carbon dioxide (CO2) generated by anthropogenic activities and the expected future growing production of them are even now a serious ecological problem. One of possibilities of solving this situation is CO2 storage, i.e. the building of CO2 storage sites in suitable parts of the rock mass. They are represented, in addition to ideal localities, which are mined-out deposits of natural gas and oil, by selected geological formations of sedimentary Carboniferous deposits of hazd coal, it means localities of closed underground hard coal mines provided that they are ''tight'' enough. For the purposes of CO2 geosequestration, theoretically all closed hard coalfields exploited using the underground method in the Czech Republic can be considered, namely the Rosice-Oslavany (RUD), Kladno, Zacler-Svatonovice and Most Coalfields, and partial localities (closed mines) in the Czech part of Upper Silesian Hard Coal Basin (Ostrava-Karvina Coalfield). Of hydrocarbon deposits situated especially in the Vienna Basin, the Poddvorov, Nitkovice, Kostelany-vychod and Zdanice-zapad structures seem to be most promising.
PL
Obecne emisje dwutlenku węgla (CO2) pochodzenia antropogenicznego oraz przewidywany w przyszłości ich wzrost nadal stanowią problem ekologiczny. Jednym ze sposobów rozwiązania tego problemu jest magazynowanie CO2 tzn. budowanie miejsc magazynowania CO2 w nadających się do tego częściach górotworu. Należą do nich takie idealne miejsca, jak wyeksploatowane przestrzenie po produkcji gazu ziemnego i ropy naftowej, jak również niektóre formacje geologiczne, np. skały osadowe Karbonu z wyeksploatowanymi i odpowiednio szczelnymi złożami węgla kamiennego. Geosekwestracja CO2 wykonywana jest w zasadzie na wszystkich czeskich złożach węgla kamiennego eksploatowanych metodą podziemną, tj. Rosice-Oslavany (RUD), Kladno, Zacler-Svatonovice, w większości złóż, jak również w częściowo zlikwidowanych kopalniach czeskiej części Górnośląskiego Zagłębia Węglowego (Ostrava-Karvina). Spośród złóż zlokalizowanych w Basenie Wiedeńskim, najbardziej obiecujące wydają się być złoża Poddvorov, Nitkovice, Kostelany-vychod i Zdanice-zapad.
PL
W praktyce wykorzystywany jest dwutlenek węgla pozyskiwany ze źródeł naturalnych, jak i otrzymywany sztucznie w różnych procesach technologicznych. Tendencja powrotu w ostatnich latach do stosowania w przemyśle spożywczym i farmaceutycznym CO2 pochodzącego ze źródeł naturalnych oraz zwiększone wymagania odnośnie czystości tego gazu, podyktowały potrzebę doskonalenia zagadnień dotyczących jego uzdatniania. W artykule, na przykładzie dwutlenku węgla separowanego z wód mineralnych, przedstawiono problemy osuszania gazu przy użyciu sit molekularnych, eliminacji węglowodorów metodą adsorpcyjną na węglu aktywnym i głębokiego odsiarczania CO2 przy użyciu impregnowanego węgla aktywnego. Wytypowanie wymienionych wyżej technologii uzdatniania CO2 wynika ze sposobu zagospodarowania tego gazu.
EN
CO2 used in practice is obtained from natural sources and technological processes. In last years CO2 used in pharmaceutical and food industry is obtained from natural sources. Because of that it is necessary to improve process of it treatment. In this paper problems of gas drying on molecular sieve, hydrocarbon adsorption on active carbon and deep desulfurization on impregnated active carbon were presented on example of CO2 separated from mineral water. Selection of these technologies of CO2 treatment come from method of management than gas.
EN
Shale gas in the United States over the past decade, and interest has spread to potential gas shales in Canada, Europe, Asia, and Australia. One analyst expects shale gas to supply as much as half the natural gas production in North America by 2020. Carbon dioxide capture and storage (CCS) is a set of technologies for the capture of CO2 from its anthropogenic point sources, its transport to a storage location, and its geosequestration. This is only one, though very important, option in a portfolio of actions to fight the increase of atmospheric CO2 concentration and to mitigate climate change, while at the same time allowing for the continued use of fossil fuels. Deployment of CCS technologies is expected to be limited in the next 5-10 years, but to contribute significantly to the reduction of CO2 emissions 20 years from now. Capture of CO2 using existing separation techniques can be applied to large point sources, i.e. power plants or industrial plants; CO2 can be easily transported over large distances using pipelines and ships; finally CO2 can be permanently stored in suitable deep geological formations, namely deep saline aquifers, oil or gas reservoirs, and unmineable coal seams, or it can be fixed in carbonates. The paper deals with the innovative method of carbon dioxide storage coupled with gas shale fracturing and methane recovery developed in the Military University of Technology. It allows to effectively mine the shale gas and to store carbon dioxide in shale rock. It must be noticed that CO2 pollution is a very important problem in Poland, because of European Union CO2 limits. Also carbon dioxide thermodynamic process of decompression numerical calculation, which simulates the injection of the cold liquid gas into the shale formation (high temperature and pressure conditions) and its influence on shale rock fracturing as well as initial experimental verification of the method was presented in the paper.
EN
Within this study, the usefulness of different zeolites, such as natural clinoptilolite from Ukraine, synthetic zeolites manufactured by Soda Works of Inowrocław, and zeolites obtained in the laboratory on the basis of fly ashes has been verified and compared as the adsorbents of CO2 from a model mixture of flue gas. The adsorption capacity of carbon dioxide was examined at different temperatures and at different velocity of the gas mixture flowing through an adsorption bed. The obtained results have enabled the assumption to be put forward that the use of cheap natural clinoptilolite and zeolites synthesized on the basis of fly ashes may prove very useful for removing carbon dioxide, being competitive, at the same time, to the predominatly used synthetic zeolites.
PL
W artykule dokonano wstępnego sprawdzenia i porównania przydatności różnego typu zeolitów: naturalnego klinoptilolitu, zeolitów syntetycznych, laboratoryjnie otrzymanych zeolitów na bazie popiołów lotnych - jako adsorbentów CO2 z modelowej mieszaniny gazów odlotowych. Zdolność adsorbcji dwutlenku węla przez zeolity zbadana została w różnych temperaturach i przy różnych prędkościach przepływu mieszaniny gazów przepływającej przez zlóża adsorpcyjne.
17
Content available remote Analiza techniczno-ekonomiczna sprężania i skraplania CO2 w Uzdrowisku Krynica
80%
PL
W artykule przedstawiono problem zagospodarowania dwutlenku węgla wydobywanego z odwiertów Zuber w Krynicy. Przeprowadzone zostały obliczenia zużycia energii dla sprężania i skraplania CO2. Rozpatrzono wariantowe rozwiązanie polegające na sprężaniu części gazu do ciśnienia 0,7 MPa i pozostałej ilości CO2 przeznaczonej do skraplania do ciśnienia 8 MPa. W wyniku przeprowadzonej analizy zużycia energii przypadającej na jednostkę sprężanego gazu, przy uwzględnieniu instalacji do odsiarczania tego gazu, zaproponowano inną wersję rozwiązania, w której całość CO2 będzie skraplana, a gaz do rozlewni wód mineralnych oraz do suchych kąpieli doprowadzany będzie po regazacji.
EN
The problem of management of carbon dioxide exploited from the Zuber wells in Krynica is presented. Calculations of energy consumption during compression and liquefaction of CO2, were carried out. An alternative design is discussed based on the partial compression of a gas to the pressure of 0,7 MPa and the compression of the remaining part of CO2, (designed for liquefiction) to the pressure of 8 MPa. As a result of analysis of power consumption per volume unit of the compressed gas, the modification of the existing installation is proposed with consideration of the sulphur removal system. According to this proposition, the whole amount of CO2, will be liquefied. Part of the gas will be transported to the mineral water bottling plant and the rest to the spa installation (dry bath) for further use.
PL
Zaproponowano przebadanie możliwości podziemnego magazynowania COj w Polsce, w głębokich strukturach geologicznych (ropo-, gazo-i wodonośnych). Na obszarach, gdzie zlokalizowane są duże punktowe źródła emisji dwutlenku węgla (elektrownie i elektrociepłownie zawodowe) planuje się przeprowadzenie badań jgeologiczno-gór-niczych w celu wytypowania miejsc podziemnego składowania tego gazu. Wymaga to przeanalizowania warunków geologiczno-złożo-wych, przy uwzględnieniu uwarunkowań górniczych i prawnych w połączeniu z miejscami emisji CO2. Realizacja projektu badań jest pionierska, posiada znaczenie badawcze i praktyczne, nie tylko w skali Polski. Umożliwi przygotowanie naukowych podstaw pod przyszłą instalację podziemnego składowania CO2.
EN
It is proposed to give a through examination to possibilities of underground storage of CO2 in Poland in the deep geological structures (oil-, gas- and water-bearing). On the areas where the big emission sources of carbon dioxide are situated (power plants and power and heat generating stations) one plans to conduct geological and mining research to determine the places for underground storage of this gas. It requires to analyse geological and deposit conditions at taking into consideratiorTmining and legal conditions in relation to the places of CO2 emission. Realisa i i on of this research project is a pioneer task, it has research and practk ,.i importance not only for Poland. It enables preparation of the scientific basis for a future installation for underground CO2 storage.
19
Content available Ways of reducing carbon dioxide from road transport
80%
EN
Climate change and the associated global warming affect all of us. These changes cause the melting of the glaciers and consequently the increase in sea and ocean levels. This phenomenon threatens the existence of some of the island states. The warming casing all this was brought on by the economic activity of humans, with the greatest responsibility being attributed to the ever-increasing production of greenhouse gases. Transport generates large portion of these gases. When means of transport are in motion, they are affected by certain driving resistances which try to keep vehicle from moving. In order to overcome them, it is necessary to produce certain useful work equivalent to the measurement of driving resistances. An internal combustion motor is the most frequent source of such energy. It generates energy by oxygenating hydrocarbon fuels, and in addition to the useful work, it produces also unfavourable emission. The amount of such emissions equals to the amount of burnt fuel. Thus, levels of emissions can drop by reducing fuel consumption. The most commonly mentioned gas is the CO2. Reduction of CO2 production is essential to affect the high level of CO2. The article focuses on the possibilities of reducing CO2 from road transport. The possibilities of reducing CO2 from road transport are quantified in the form of mathematical model calculations.
EN
Many large cities in Europe are currently trying to reduce the amount of harmful substances for the residents. Road transport is also an important source of air pollution. One way to reduce pollutant production is to operate more environmentally friendly vehicles. The paper analyses data obtained during practical tests of a hybrid vehicle in urban traffic. The individual components of the exhaust gases are calculated in g/km and they are compared with the values for conventional vehicle propulsion. The data was obtained through a commercially available exhaust gas analyzer and a calculated amount of emissions produced from available data from the engine control unit. The results shown that using of this type of propulsion has its importance in cities with increased air pollution. During urban operation, the hybrid-powered vehicle was powered by an electric engine up to 67.70% (75.40% of the time). As a result of operating such a vehicle in the city, emissions of CO2, HC and NOx are significantly lower.
first rewind previous Strona / 36 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.