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Application of catalysts in the treatment of selected waste chloroorganic compounds

Żarczyński A., Zaborowski M., Paryjczak T., Gorzka Z., Kaźmierczak M.

Polish Journal of Chemical Technology

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2007

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Vol. 9, nr 2

61-64

EN

Tetrachloromethane (TCM) and 1,1,2,2-tetrachloroethane (TChE) were oxidized in the temperature range from 300 to 600°C and at contact time of 0.36 s. The following catalysts were applied during the process: the granular one - platinum (0.12%) at the TiO2-SiO2 carrier, platinum ZChO-80 (0.15%) at γ-Al2O3 carrier, palladium (1%) at γ-Al2O3 carrier and monolithic platinum-rhodium catalyst (Pt - 0.09% and Rh - 0.04%) at the cordierite carrier. The substrates were oxidized in the presence of the above mentioned catalysts with various efficiencies depending on the molecular structure and the type of the catalyst. Palladium contact appeared to be the most active among the others. In the presence of this catalyst, total oxidation of TCM and TChE proceeded at the temperature of 425 and 500°C, respectively. The content of PCDD/Fs in gaseous products obtained during the oxidation of both substrates, was significantly lower than the admissible value of the toxicity equivalent (0.1 ng TEQ/m3).

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Dioxins in the process of 1,1,2,2-tetrachloroethane oxidation with the application of monolithic catalysts

Żarczyński A., Gorzka Z., Paryjczak T., Kaźmierczak M., Szczepaniak B.

Polish Journal of Chemical Technology

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2005

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Vol. 7, nr 2

100-104

EN

The activity of three monolithic catalysts with ceramic constitution were investigated in the process of 1,1,2,2-tetrachloroethane oxidation (TChE). One of the catalysts contained rhodium and platinum at the intermediate layer with gamma-Al2O3. The second one contained platinum at ZrO2 and the third one - platinum at TiO2. The gaseous and liquid products of the reaction were analysed in order to determine the contents of polychlorinated dibenzo-p-dioxins and dibenzofuranes (PCDD/Fs). The process temperature was ranging from 400 to 700°C. The contact time was 0.36 s. The total oxidation of TChE was found to be achieved at the temperature of 550°C with the application of the monolithic platinum-rhodium catalyst or at higher temperatures with the application of other catalysts. The presence of the most toxic congener of PCDD/Fs, i.e. 2,3,7,8-TCDD, was not observed in the reaction products. Only the single less toxic congeners at the concentrations significantly lower than 0.1 ngTEQ/m^3 (the admissible value in Poland and other EU countries) were determined in the combustion gases. If zirconium catalyst was applied in the process, then no presence of PCDD/Fs congeners was found in the combustion gases.

3

Oxidation of 1,1,2,2-tetrachloroethane on platinum and rhodium monolithic catalysts

Żarczyński A., Gorzka Z., Kaźmierczak M., Szczepaniak B., Stufka-Olczyk J.

Polish Journal of Applied Chemistry

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2005

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Vol. 49, nr 3

237-244

EN

The activity of two monolithic catalysts containing platinum and rhodium at intermediate layer with γ-Al2O3 was investigated in the process of 1,1,2,2-tetrachloroethane oxidation (TChE). The catalysts contained the washcoat deposited on ceramic support or kanthal foil. Gaseous and liquid reaction products were analysed in order to determine the contents of polychlorinated dibenzo-p-dioxins and dibenzofuranes (PCDD/Fs). The process temperature was ranging from 400 to 650 °C. The contact time was 0.36 s. Total oxidation of TChE was observed at the temperature of 550 °C in the case of ceramic platinum-rhodium catalyst and at 625 °C in the case of catalyst with metallic carrier. PCDD/Fs components were detected in combustion gases with concentrations significantly lower than 0.1 ng TEQ/m3 (the admissible value in Poland and EU countries).

4

Dioksyny w procesie utleniania 1,1,2,2- tetrachloroetanu w obecności wybranych katalizatorów

Żarczyński A., Kaźmierczak M., Gorzka Z., Zaborowski M.

Chemia i Inżynieria Ekologiczna

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2005

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Vol. 12, nr s1

113-122

PL

Utleniano 1,1,2,2-tetrachloroetan (TChE) z udziałem katalizatorów zawierających platynę: ZChO-80 i Pt/TiO2-SiO2 oraz katalizatora hopkalitowego HA-100 w zakresie temperatur 300-600°C przy czasie kontaktu 0,36-0,60 s. Stwierdzono, że całkowite utlenianie TChE w obecności katalizatorów platynowych zachodziło w temperaturze 500°C przy czasie kontaktu 0,36 s. Proces nie powodował powstawania 2,3,7,8-TCDD w temperaturze 450°C, natomiast w spalinach były obecne w śladowych stężeniach inne kongenery PCDD/Fs. Równoważniki toksyczności próbek spalin w tej temperaturze wynosiły dla badanych katalizatorów: 0,015 ng TEQ/m3 (ZChO-80), 0,088 ng TEQ/m3 (Pt/TiO2-SiO2) i 0,1085 ng TEQ/m3 (HA-100). Uzyskane wyniki świadczą o możliwości obniżenia do 500°C temperatury unieszkodliwiania odpadowych, tetrachloropochodnych etanu z udziałem badanych katalizatorów platynowych w porównaniu z obecnie stosowanym w przemyśle spalaniem wysokotemperaturowym (I 200-1 500°C).

EN

1,1,2,2-tetrachloroethane (TChE) was oxidised with application of catalysts containing platinum: ZChO-80, Pt/TiO2-SiO2 and hopcalite HA-100, in the temperature range from 300 to 600°C and at contact time of 0.36 to 0.60 s. Total oxidation of TChE in the presence of platinum catalysts was achieved in a temperature of 500°C and at the contact time of 0.36 s. The process did not result in formation of 2,3,7,8-TCDD in a temperature of 450°c. However, combustion gases contained trace amounts of PCDD/Fs congeners. In this temperature, toxicity equivalents in samples of combustion gases obtained in this process with application of a catalysts were follows: 0.015 (ZChO-80), 0.088 (Pt/TiO2-SiO2) and 0.1085 ng TEQ/m3 (HA-100). Results of investigations prove the possibility of the temperature decrease to 500°C during treatment of waste tetrachloro-derivatives of ethane with application of platinum catalysts, in comparision with high temperature combustion (1200-1500°C) currently used in industry.