Návrh jednotky pro katalytickou oxidaci VOC a CO

Design of catalytic oxidation unit for elimination of VOC and CO

journal article in Web of Science

en

Treatments of waste gas as well as solid and liquid wastes are important activities for environmental protection. A thermal oxidation is most used method for VOC abatement from process off-gases. But the consumption of natural gas is often considerable and running costs of such equipment are very high. This is the main reason, why companies are searching for technologies that decreases the consumption of natural gas but still meeting current emission limits. In many cases, the thermal oxidation is appropriate replace to the catalytic oxidation technology. A mathematical model of an ideal plug flow packed bed adiabatic reactor for catalytic oxidation of VOC and CO was created to support a design of catalytic oxidation unit (pilot plant reactor). Industrial catalyst EnviCat based on Pt and Pd applied on the Al2O3 support was used. In the 1st proposed mathematical model, the maximum working temperature of the catalyst was exceeded. Thus, the catalytic bed had to be divided into two parts. Cooling air was injected between the two catalytic beds. Catalytic oxidation unit (pilot plant reactor) was designed according to the results of the mathematical model. The experimental data are in good agreement with the results of the mathematical model, although a very simplified model was used.

Zpracování plynných akpalných odpadů je velice důležité pro ochranu životního prostředí. Jednou z nejpoužívanějších metod na odstraňování VOC z procesních odplynů je termická oxidace. Tato metoda ovšem spotřebobává velké množství zemního plynu a její provoz je velice nákladný. To je důvod, proč v průmyslu hledají nové technologie, které dodsžují emisní limity, ale mají nižší provozní náklady. V mnoho případech je tak vhodnější nahradit termickou oxidaci technologií katalytické oxidace. Pro návrh poloprovozní katalytické jednotky na odstraňování VOC a CO byl použit matematický model adiabatického reaktoru se sypaným ložem a s pístovým tokem. Jako katalyzátor byl použit průmyslový katalyzátor EnviCat obsahující Pt a Pd na nosiči Al2O3. Z prvních výsledků modelu bylo zjištěno, že je v reaktoru překročena maximální pracovní teplota katalyzátoru. Z toho důvodu bylo katalytické lože rozděleno na dvě části a mezi ně byl přiveden chladící vzduch. Podle těchto výsledků byla navržena poloprovozní katalytická jednotka. Experimentální data z měření ukazují dobrou shodu s matematickým modelem, ačkoliv byl použit velmi zjednodušený model.

Treatments of waste gas as well as solid and liquid wastes are important activities for environmental protection. A thermal oxidation is most used method for VOC abatement from process off-gases. But the consumption of natural gas is often considerable and running costs of such equipment are very high. This is the main reason, why companies are searching for technologies that decreases the consumption of natural gas but still meeting current emission limits. In many cases, the thermal oxidation is appropriate replace to the catalytic oxidation technology. A mathematical model of an ideal plug flow packed bed adiabatic reactor for catalytic oxidation of VOC and CO was created to support a design of catalytic oxidation unit (pilot plant reactor). Industrial catalyst EnviCat based on Pt and Pd applied on the Al2O3 support was used. In the 1st proposed mathematical model, the maximum working temperature of the catalyst was exceeded. Thus, the catalytic bed had to be divided into two parts. Cooling air was injected between the two catalytic beds. Catalytic oxidation unit (pilot plant reactor) was designed according to the results of the mathematical model. The experimental data are in good agreement with the results of the mathematical model, although a very simplified model was used.

Katalyticka oxidace, VOC, CO, poloprovozní jednotka, reaktor se sypaným ložem

Catalytic oxidation, VOC, CO, pilot plant, packed bed reactor

2014

15.01.2014

0888-5885

53

2

732–737

6