Interaction of trifluoromethane (CHF3) with alkali hydroxides and carbonates

Vakulka, Andrii; Tavčar, Gašper; Škapin, Tomaž

doi:10.1016/j.jfluchem.2012.06.017

Cited by 13 publications

(19 citation statements)

References 32 publications

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“…Recently, technologies such as catalytic decomposition and thermal pyrolysis have been proposed for the destruction of CHF 3 . Alternatively, it was discovered that CCl 2 F 2 , CBrClF 2 , CHClF 2 , and CHF 3 can be converted into unsaturated HFC, CH 2 =CF 2 via reaction with CH 4 or CH 3 Br …”

Section: Introductionmentioning

confidence: 99%

Promotion of O₂ on the co‐pyrolysis of CHF₃ and CH₄ for VDF synthesis

et al. 2017

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Co‐pyrolysis of CHF3 and CH4 in the presence of O2 was investigated in a tubular reactor at temperatures between 700 and 860°C, atmospheric pressure, and residence time of 1.64 s. Under reaction conditions studied, introduction of O2 in the CHF3 and CH4 feed significantly improves the conversion of CH4, and while conversion of CHF3 almost stays unchanged. In the absence of O2, CH4 is activated by chain reactions which are initiated by the surface of the reactor. Following the introduction of O2, a series of additional chain reactions (reactions of CH4 with O2, O•, •HO2 and •OH radicals) generate more •CH3 radicals which are one of the key species for the formation of target product, CH2=CF2. Therefore, formation rate of CH2=CF2 is doubled under optimal reaction conditions. The suitable O2/CH4 feed ratio is suggested to be 0.06 for the formation of CH2=CF2. In addition, introduction of O2 in the feed decreases the formation of major byproduct C2F4 and C2HF3 significantly. After O2 is introduced, as more H• radicals are produced, improved formation rate of C2H3F results. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.

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Section: Introductionmentioning

confidence: 99%

Promotion of O₂ on the co‐pyrolysis of CHF₃ and CH₄ for VDF synthesis

et al. 2017

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“…In addition, unlike AC -HNO 3 , no formation of CF 4 and C 2 F 6 was detected during all the experiments except small amounts of CO and CO 2 . In the presence of some metal hydroxides, for example KOH and NaOH, CHF 3 interacts with -OH strongly with the formation of CO [7]. This can be readily understood from the basicity and acidity of alkali metal hydroxides and CHF 3 .…”

Section: Effect Of Hydroxyl Groupsmentioning

confidence: 99%

“…The methodology is widely applicable to a variety of silicon-, boron-, and sulfur-based electrophiles, as well as carbon-based electrophiles and is a welcome extension of the toolbox for trifluoromethylation [6]. As CHF 3 is a very weak carbon acid with an estimated pK a of 26 -28, it interacts with solid alkali hydroxides and carbonates at elevated temperatures with the formation of metal fluoride, CO and H 2 O [7]. Another method includes catalytic hydrolysis with phosphates and ZrO 2 -SO 4 in the presence of O 2 and steam at relatively low temperatures [8,9].…”

Section: Introductionmentioning

confidence: 99%

Pyrolysis of Trifluoromethane over Activated Carbon: Role of the Surface Oxygen Groups

Han

Jin

Chen

et al. 2014

Progress in Reaction Kinetics and Mechanism

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The pyrolysis of CHF 3 and CHClF 2 over activated carbons was investigated at 823 K, GHSV of 1820 h -1 and pressure of 1 bar. To elucidate the mechanism, activated carbons were treated in H 2 at 1123 K, HNO 3 solution at 363 K, N 2 at 873 K or supported with 4 wt% poly(acrylic acid sodium salt), respectively. The results confirm that following different treatments, the concentration of surface oxygen groups on activated carbons varies dramatically. These surface groups play important roles in the decomposition of CHF 3 and the product profiles. It is suggested that carboxylic groups are responsible for the formation of CF 3 and ultimately the product C 2 F 6 which results from the coupling of CF 3 , while the interaction between CHF 3 and hydroxyl or lactonic groups leads to the total destruction of CHF 3 and production of CO and CO 2 . Pyrolysis of CHClF 2 over activated carbon confirms that surface oxygen groups have no noticeable influence on the reactions of CF 2 . By contrast, a pure carbon surface is responsible for the disproportionation of CF 2 and formation of CF 3 .

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“…Several abatement techniques for CHF 3 have been suggested, such as thermal processes [2,3], catalysts [4,5], plasma [6,7], and conversion to environmentally benign compounds [8]. A thermal process is an effective method for the decomposition of CHF 3 , and has been used widely under the clean development mechanism methodologies (CMD) [9,10].…”

Section: Introductionmentioning

confidence: 99%

Process conditions for complete decomposition of CHF3 in a dielectric barrier discharge reactor

Nguyen

Lee

2016

Korean J. Chem. Eng.

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Plasma decomposition of CHF 3 was investigated using a dielectric barrier discharge immersed in an electrically insulating oil bath in a mixture of CHF 3 , O 2 , and N 2 . CHF 3 was well decomposed under a relatively high applied voltage in an atmospheric pressure plasma system. The main by-product was CO 2 and its selectivity increased with a decrease in the CHF 3 concentration in the feed. Complete decomposition of CHF 3 was achieved at a typical process range: an applied voltage ≥ 7.0 kVp, an initial CHF 3 flow rate of 3 ml/min, and a total flow rate of 500 ml/min. The value of energy efficiency and energy density at the center range for the complete decomposition of CHF 3 was 0.01 mmol/kJ and 6.00 kWh/Nm 3 , respectively.

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Interaction of trifluoromethane (CHF3) with alkali hydroxides and carbonates

Cited by 13 publications

References 32 publications

Promotion of O₂ on the co‐pyrolysis of CHF₃ and CH₄ for VDF synthesis

Promotion of O₂ on the co‐pyrolysis of CHF₃ and CH₄ for VDF synthesis

Pyrolysis of Trifluoromethane over Activated Carbon: Role of the Surface Oxygen Groups

Process conditions for complete decomposition of CHF3 in a dielectric barrier discharge reactor

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Interaction of trifluoromethane (CHF3) with alkali hydroxides and carbonates

Cited by 13 publications

References 32 publications

Promotion of O2 on the co‐pyrolysis of CHF3 and CH4 for VDF synthesis

Promotion of O2 on the co‐pyrolysis of CHF3 and CH4 for VDF synthesis

Pyrolysis of Trifluoromethane over Activated Carbon: Role of the Surface Oxygen Groups

Process conditions for complete decomposition of CHF3 in a dielectric barrier discharge reactor

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Product

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Promotion of O₂ on the co‐pyrolysis of CHF₃ and CH₄ for VDF synthesis

Promotion of O₂ on the co‐pyrolysis of CHF₃ and CH₄ for VDF synthesis