Wyniki wyszukiwania - Biblioteka Nauki

1

Activated bio-carbons prepared by physical activation of residues after supercritical extractionof raw plants

100%

Bazan-Woźniak A. , Pietrzak R.

Physicochemical Problems of Mineral Processing

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2019

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tom Vol. 55, iss. 6

1357--1365

EN

A series of activated bio-carbons has been obtained by physical activation of residues after supercritical extraction of blackberries, raspberries and blackcurrants. The effects of different temperatures of activation and different starting materials on the physicochemical and sorption properties of the bio-carbon samples obtained were evaluated. The physicochemical properties of the activated bio-carbons were characterized by elementary analysis, low-temperature nitrogen sorption and Boehm titration. All materials were tested as adsorbents of pollutants from gas (nitrogen dioxide) and liquid (iodine, methylene blue) phase. The sorption properties of the activated bio-carbons were tested at 23°C. The materials obtained were activated bio-carbons of surface area ranging between 303 and 442 m2/g and showing basic character of the surface. The content of elemental carbon in the obtained samples was in the range of 73.4-82.1 wt. %. The maximum adsorption capacities of the materials towards nitrogen dioxide were 65 mg/g, methylene blue -207 mg/g, and iodine 1001 mg/g. According to the adsorption tests towards nitrogen dioxide, the sorption capacities of the adsorbents studied were increased if a mixture of nitrogen dioxide and air had a humidity of 70 %. The mechanism of methylene blue adsorption involved the formation of adsorptive multilayer. The most effective adsorbent of organic and inorganic pollutants proved to be the activated bio-carbon obtained from the residues after supercritical extraction of blackcurrants.

2

Preparation of sorbents from selected polymers

100%

Ciesińska W. , Makomaski G. , Zieliński J. , Brzozowska T.

Polish Journal of Chemical Technology

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2011

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tom 13

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nr 1

51-54

EN

In this work, the results of studies on the preparation of sorbents from selected polymers were presented. The polymers were carbonized and subsequently physically activated by steam or carbon dioxide, or alternatively, chemically activated with potassium hydroxide. For the obtained materials, a specific area was evaluated by means of low-temperature nitrogen adsorption and benzene adsorption, iodine number was also determined. The obtained results indicated a possibility to procure hydrophobic sorbents of microporous structure. Sorbents having the best properties, i.e. the specific area of above 2000 m2/g were produced from poly(ethylene terephthalate) and phenol-formaldehyde resin.

3

Synthesis of new carbon-nitrogen composites based on waste sweet drinks

100%

Kaźmierczak-Raźna J. , Pietrzak R. , Nowicki P.

Physicochemical Problems of Mineral Processing

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2019

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tom Vol. 55, iss. 6

1366--1374

EN

The materials under investigation were new carbon-nitrogen composites obtained via pyrolysis and CO2 activation of sweet drinks destined for utilization. Waste Pepsi Cola® has been examined as an alternative and renewable carbon source for composite materials. Nitrogen was introduced into the Pepsi Cola® solution via the addition of guanidine carbonate, before the pyrolysis process. The physicochemical properties of the materials studied were characterized by low- temperature nitrogen adsorption (using BET and BJH methods), elemental analysis, FTIR spectroscopy, scanning electron microscopy (SEM) as well as determination of pHPZC and the number of surface functional groups. Additionally, thermal properties of the samples were investigated by thermogravimetric analysis (TG) and differential thermogravimetry (DTG). The final products were new carbon-nitrogen composites characterized by a very high content of nitrogen (11.2 - 21.6 wt.%) as well as relatively low surface area and pore volume reaching 198 m2/g and 0.16 cm3/g, respectively. Results of FT-IR study and Boehm titration indicated that the composites surface has clearly basic character, which was confirmed by pHpzc values above 8.0.

4

Właściwości węgli aktywnych o różnych kształtach ziaren, wytwarzanych w reakcji karbonizatu węglowego z parą wodną

86%

Buczek B.

Przemysł Chemiczny

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2016

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tom T. 95, nr 5

1006--1008

PL

Rozwinięto strukturę cylindrycznych i pierścieniowych ziaren karbonizatu węglowego w reakcji z parą wodną. Strukturę tę oceniano na podstawie izoterm adsorpcji/desorpcji azotu. Obliczono parametry struktury mikroporowatej z równania Dubinina i Raduszkiewicza, powierzchnię mezoporów metodą Dollimore’a i Heala oraz wymiar mikroporów z równania Horvatha i Kawazoe. Wyniki badań tekstury wykazały, że bardziej jednorodną strukturę mikroporowatą i lepsze właściwości mechaniczne wykazują ziarna węgla aktywnego o kształcie pierścieniowym.

EN

Cylindrical and annual carbonaceous precursors were activated by partial steam or CO2 gasification. Micropore and mesopore structures of the activated C samples with various burn-off were evaluated by N2 adsorption/desorption isotherms. Parameters of the Dubinin-Radushkevich equation were calculated, surface mesopores were detd. by the Dollimore and Heal method, as well as the micropore size distribution from the Horvath-Kawazoe equation. The annular C samples showed a uniform micropore structure and better mech. properties than the cylindrical ones.

5

Adsorption of bisphenol a from aqueous solutions by activated tyre pyrolysis char – Effect of physical and chemical activation

86%

Kuśmierek K. , Świątkowski A. , Kotkowski T. , Cherbański R. , Molga E. , Kuśmierek K. , Świątkowski A. , Kotkowski T. , Cherbański R. , Molga E.

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nr 2

6

Otrzymywanie węgli aktywnych z wierzby energetycznej. Cz. 1, Aktywacja fizyczna

86%

Jasieńko-Hałat M. , Rysz S.

Przemysł Chemiczny

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2010

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tom T. 89, nr 7

963-965

7

Acetone adsorption on CO2-activated tyre pyrolysis char – Thermogravimetric analysis

86%

Kotkowski T. , Cherbański R. , Molga E.

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nr 2

8

Acetone adsorption on co2-activated tyre pyrolysis char – thermogravimetric analysis

72%

Kotkowski T. , Cherbański R. , Molga E.

Chemical and Process Engineering

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2018

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tom Vol. 39, nr 2

233–246

EN

Activation of tyre pyrolysis char (TPC) can significantly increase its market value. To date, it has been frequently carried out in different reactors. In this work, thermogravimetric analysis was used instead. The performance of activated pyrolysis chars was tested by adsorption of acetone vapour and comparison of the equilibrium adsorption capacities for all samples. The highest equilibrium adsorption capacity was observed for the carbon burn-off of 60%. In addition, the equilibrium adsorption capacity of activated TPC decreases by about 10% after eleven adsorption/desorption cycles. Moreover, activation changed the porous structure of pyrolysis chars from mesoporous to micro-mesoporous.

9

Grzyby i odpady grzybowe jako nowe prekursory do otrzymywania adsorbentów węglowych

72%

Koźlarek N. , Bazan-Woźniak A. , Pietrzak R.

Wiadomości Chemiczne

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2022

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tom [Z] 76, 3-4

221--236

EN

Undesirable changes in the bacteriological, physical and chemical properties of water are a consequence of introduction of excessive amounts of inorganic and organic materials to it. These pollutants limit or prevent the use of water for drinking, food production and household purposes. The greatest amounts of pollutants enter the watersystem with sewage. Also the pesticides,surfactants, organic dyes, artificial fertilizers along with municipal and industrial waste can easily enter water system and threaten the organisms living there. Another, equally important problem is the pollution of atmospheric air. Emission of solid liquid or gas pollutants to the atmosphere has been proved to have significant impact on human health, climate and nature. That is why the search for new and more effective technologies for the environment purification is a continuous challenge. Recently, increasingly often carbon materials are used as effective adsorbents of pollutants from liquid and gas phases.

10

Węgle aktywne z pozostałości po ekstrakcji nadkrytycznej do usuwania ditlenku azotu

72%

Bazan A. , Nowicki P. , Pietrzak R.

Inżynieria i Ochrona Środowiska

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2016

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tom T. 19, nr 2

183--193

EN

The aim of this study was to obtain activated carbons by physical activation of the waste left after supercritical extraction of marigold and hops, provided by the Institute of New Chemical Syntheses in Puławy (Poland). The precursors were first subjected to carbonisation at 500ºC in nitrogen atmosphere. The chars were next subjected to physical activation at 700 and 800ºC in carbon dioxide atmosphere. The effect of activation temperature on the physicochemical properties of the adsorbents prepared has been tested. The carbonaceous materials were characterised by low-temperature nitrogen sorption as well as determination of the number of surface oxygen groups. The sorption properties of the chars and activated carbons obtained were characterised by nitrogen dioxide adsorption. The results have shown that activated carbons are characterised by low developed surface area varying from 2 to 413 m2/g and show alkaline character of the surface. It has been proved that appropriate choice of the activation parameters and the presence of steam have a positive effect on adsorption of nitrogen dioxide by activated carbons obtained. The highest sorption capacity toward nitrogen dioxide in wet conditions was 72.1 mg/gads, while in dry conditions it was 38.7 mg/gads. The results have also shown that future research should be aimed at the optimum choice of the temperature of activation or activating agent in order to significantly improve the textural parameters of the activated carbons.

PL

W pracy przedstawiono wyniki badań, których celem było otrzymanie węgli aktywnych na drodze aktywacji fizycznej pozostałości po ekstrakcji nadkrytycznej szyszek chmielu oraz nagietka. Surowce roślinne pozyskano z Instytutu Nowych Syntez Chemicznych w Puławach. Materiały wyjściowe poddano w pierwszej kolejności procesowi karbonizacji w temperaturze 500ºC w atmosferze azotu. Otrzymane karbonizaty poddano następnie aktywacji fizycznej za pomocą ditlenku węgla w 700 i 800ºC. Zbadano wpływ temperatury aktywacji na właściwości fizykochemiczne otrzymanych węgli aktywnych. Materiały węglowe scharakteryzowano za pomocą niskotemperaturowej adsorpcji/desorpcji azotu oraz oznaczono zawartość powierzchniowych tlenowych grup funkcyjnych o charakterze kwasowym i zasadowym. Dla karbonizatów i węgli aktywnych przeprowadzono pomiary adsorpcji ditlenku azotu. Na podstawie badań stwierdzono, że produkty finalne charakteryzują się słabo rozwiniętą powierzchnią właściwą, mieszczącą się w przedziale od 2 do 413 m2/g, oraz wyraźnie zasadowym charakterem powierzchni. Wykazano, że temperatura aktywacji oraz obecność pary wodnej podczas adsorpcji NO2 ze strumienia powietrza mają znaczący wpływ na zdolności sorpcyjne węgli aktywnych. Najwyższa pojemność sorpcyjna w warunkach wilgotnych wynosiła 72,1 mg/gads, natomiast w warunkach suchych 38,7 mg/gads. Uzyskane wyniki wykazały ponadto, iż niezbędna jest optymalizacja procesu wytwarzania adsorbentów, obejmująca dobór odpowiednich parametrów aktywacji oraz czynników aktywujących, w celu otrzymania węgli aktywnych o bardziej korzystnych parametrach teksturalnych.

11

Preparation of sorbents from selected polymers

72%

Ciesińska W. , Makomaski G. , Zieliński J. , Brzozowska T.

Polish Journal of Chemical Technology

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2011

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tom Vol. 13, nr 1

51-54

EN

In this work, the results of studies on the preparation of sorbents from selected polymers were presented. The polymers were carbonized and subsequently physically activated by steam or carbon dioxide, or alternatively, chemically activated with potassium hydroxide. For the obtained materials, a specific area was evaluated by means of low-temperature nitrogen adsorption and benzene adsorption, iodine number was also determined. The obtained results indicated a possibility to procure hydrophobic sorbents of microporous structure. Sorbents having the best properties, i.e. the specific area of above 2000 m2/g were produced from poly(ethylene terephthalate) and phenol-formaldehyde resin.

12

Węgle aktywne z materiałów lignocelulozowych

58%

Pawlicka A. , Doczekalska B.

Biuletyn Informacyjny Ośrodka Badawczo-Rozwojowego Przemysłu Płyt Drewnopochodnych w Czarnej Wodzie

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2013

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tom 54

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nr 1-2

13

Adsorption of bisphenol a from aqueous solutionsby activated tyre pyrolysis char – Effect of physicaland chemical activation

58%

Kuśmierek K. , Świątkowski A. , Kotkowski T. , Cherbański R. , Molga E.

Chemical and Process Engineering

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2020

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tom Vol. 41, nr 2

129–-141

EN

This paper aims to show the effect of activation method of tyre pyrolysis char (TPC) on adsorptionof bisphenol A (BPA) from aqueous solutions. The TPC was produced from end-of-life-tyres (ELT)feedstock in a pilot plant at 773 K. Activation was accomplished using two classical methods: physicalactivation with CO2and chemical activation with KOH. The two produced adsorbents had pores rangingfrom micro- to macropores. Distinct differences in the BET surface areas and pore volumes betweenthe adsorbents were displayed showing better performance of the chemically activated adsorbent foradsorption of BPA from water.The results of the kinetic studies showed that the adsorption of BPA followed pseudo-second-orderkinetic model. The Freundlich, Langmuir, Langmuir–Freundlich and Redlich–Peterson isotherm equa-tions were used for description of the adsorption data. The Langmuir–Freundlich isotherm model bestfits the experimental data for the BPA adsorption on both adsorbents. The Langmuir–Freundlichmonolayer adsorption capacity,qmLF, obtained for the CO2-activated tyre pyrolysis char (AP-CO2)and KOH-activated tyre pyrolysis char (AP-KOH) were 0.473 and 0.969 mmol g

14

Właściwości fizykochemiczne i sorpcyjne węgli aktywnych otrzymanych przez aktywację skór owoców cytrusowych oraz niskiej jakości węgla brunatnego

58%

Nowicki P. , Kaźmierczak-Raźna J. , Pietrzak R.

Inżynieria i Ochrona Środowiska

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2016

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tom T. 19, nr 3

341--352

EN

Common citrus fruit peels (banana, grapefruit and orange) as well as low quality lignite were used as precursors for the preparation of cheap activated carbons. In the first step, each of the precursors was air-dried at 110°C, crushed and sieved to the grain size of 5÷6 mm. Next the crushed materials were divided into two parts and subjected to two different treatments: direct activation of the precursors with carbon dioxide or pyrolysis of raw materials followed by physical activation with carbon dioxide. The effect of two variants of thermo-chemical treatment on the elemental composition, textural parameters and acidicbasic character of the surface of adsorbents prepared has been tested. Finally, the activated carbons were tested as adsorbents against two very hazardous and widespread gas pollutants, namely nitrogen dioxide and hydrogen sulphide, as well as toward inorganic and organic liquid pollutants represented by iodine and methylene blue. Depending on the precursor as well as method of preparation, the final products were microporous or mesoporous activated carbons with rather poorly developed surface area ranging from 107 to 527 m2/g and total pore volume from 0.09 to 0.37 cm3/g, showing strongly basic character of the surface. The results obtained have also proved that a proper choice of activation procedure for biomass or low quality lignite allows to produce effective adsorbents with good sorption capacity toward gaseous and liquid pollutants, especially for nitrogen dioxide and iodine.

PL

W pracy przedstawiono wyniki badań nad otrzymywaniem węgli aktywnych ze skór owoców cytrusowych oraz niskiej jakości węgla brunatnego. Adsorbenty węglowe otrzymano na drodze aktywacji bezpośredniej prekursorów oraz aktywacji fizycznej karbonizatów za pomocą tlenku węgla(IV). Zbadano wpływ wariantu aktywacji na skład elementarny, parametry teksturalne i właściwości kwasowo-zasadowe wytworzonych materiałów węglowych, a także na efektywność usuwania tlenku azotu(IV) i siarkowodoru ze strumienia powietrza oraz jodu i błękitu metylenowego z roztworów wodnych. Na podstawie przeprowadzonych badań stwierdzono, że produkty aktywacji charakteryzują się dość przeciętnie rozwiniętą powierzchnią właściwą mieszczącą się w przedziale od 107 do 527 m2/g i całkowitą objętością porów wynoszącą od 0,09 do 0,37 cm3/g. Wykazano również, że zarówno aktywacja bezpośrednia prekursorów, jak i aktywacja fizyczna karbonizatów za pomocą CO2 prowadzi do uzyskania materiałów o wysokiej zawartości popiołu i wyraźnie zasadowym charakterze powierzchni. Przeprowadzone testy sorpcyjne wykazały ponadto, iż węgle otrzymane poprzez aktywację skór owoców cytrusowych oraz niskiej jakości węgla brunatnego charakteryzują się dobrymi zdolnościami sorpcyjnymi wobec zanieczyszczeń gazowych i ciekłych, w szczególności wobec tlenku azotu(IV) i jodu.