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The influence of alkaline promoters on the properties of the Ni/HAp catalyst in the methane dry reforming reaction

Cichy Marcin, Zawadzki Witold

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 4

art. no. 182856

EN

The reforming of methane with carbon dioxide is still of great interest due to the ever-increasing demand for synthesis gas and hydrogen. This process makes it possible to use two major gases that are considered harmful to the environment. The main problem for its commercial application is the lack of a catalyst that is both active, selective towards syngas (a mixture of hydrogen and carbon monoxide) and resistant to deactivation by coke deposition. Nickel is the most commonly used metal in methane reforming reactions due to its high activity and reasonable price. But still there is a gap in the literature for research on novel catalysts and their properties modifications devoted to strategies to reduce deactivation of the catalysts caused by the coke formation. In the present work a series of hydroxyapatite supported nickel catalysts promoted by alkali metals (Li, Na, K and Cs) were tested. The surface and structural properties of the catalysts were well characterized by physicochemical methods. Activity and selectivity were measured at 600ºC for 20 hours’ time-on-stream test. Resistance to coking was measured with Magnetic Suspension Balance. The stability of the catalyst was improved by the addition of promoters, which reduced the rate of coking. In particular, the cesium-promoted Ni/HAp catalyst significantly inhibited coke deposition, while slightly reducing methane conversion and selectivity to hydrogen.

2

Microwave plasma for hydrogen production from liquids

Czylkowski D., Hrycak B., Miotk R., Jasiński M., Mizeraczyk J., Dors M.

Nukleonika

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2016

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Vol. 61, No. 2

185--190

EN

The hydrogen production by conversion of liquid compounds containing hydrogen was investigated experimentally. The waveguide-supplied metal cylinder-based microwave plasma source (MPS) operated at frequency of 915 MHz at atmospheric pressure was used. The decomposition of ethanol, isopropanol and kerosene was performed employing plasma dry reforming process. The liquid was introduced into the plasma in the form of vapour. The amount of vapour ranged from 0.4 to 2.4 kg/h. Carbon dioxide with the fl ow rate ranged from 1200 to 2700 NL/h was used as a working gas. The absorbed microwave power was up to 6 kW. The effect of absorbed microwave power, liquid composition, liquid fl ow rate and working gas fl ow rate was analysed. All these parameters have a clear infl uence on the hydrogen production effi ciency, which was described with such parameters as the hydrogen production rate [NL(H2)/h] and the energy yield of hydrogen production [NL(H2)/kWh]. The best achieved experimental results showed that the hydrogen production rate was up to 1116 NL(H2)/h and the energy yield was 223 NL(H2) per kWh of absorbed microwave energy. The results were obtained in the case of isopropanol dry reforming. The presented catalyst-free microwave plasma method can be adapted for hydrogen production not only from ethanol, isopropanol and kerosene, but also from different other liquid compounds containing hydrogen, like gasoline, heavy oils and biofuels.

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Procesy chemiczne i elektrochemiczne w wybranych nowych technologiach gazu ziemnego

Warowny W., Siemek J.

Wiertnictwo, Nafta, Gaz

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2007

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T. 24, z. 2

915-927

PL

W pracy przedstawiono podstawowe informacje dotyczące chemicznej konwersji gazu ziemnego, w tym reakcje konwersji metanu i rysunek z produktami konwersji gazu ziemnego. Opisano skrótowo kilka technologii dla gazu ziemnego, wśród nich: przetwórstwo gazu ziemnego na paliwa ciekłe (GTL), jego suchy reforming oraz (poprzez gaz syntezowy) produkcję wodoru, metanolu, eteru dwumetylowego (DME) i dodatków motoryzacyjnych. Dodatkowo podano elektrochemiczne procesy zachodzące w ogniwach paliwowych.

EN

This paper contains basic information for chemical conversion of the natural gas, including reforming reactions of methane and picture with gathered reforming products of natural gas. Few new selected natural gas technologies have been shortly described, among them: gas to liquid (GTL), dry reforming, production (via synthesis gas) of the hydrogen, methanol, and dimethyl ether (DME) and some motor additions. Additionally, electrochemical processes for fuel cells have been given.