Gas-phase photocatalytic oxidation of motor fuel oxygenated additives

Methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) were oxidized in the gas phase by photocatalytic oxidation (PCO). Transient PCO was carried out at room temperature on TiO2 (Degussa P25), 0.2% Pt-TiO2, and 2% Pt-TiO2 catalysts. Surface-adsorbed reaction by-products were characterized by temperature-programmed desorption (TPD) and oxidation (TPO). Continuous flow PCO was also carried out at 373 K on TiO2. Acetone, H2O, and CO2 were the gas-phase products for PCO of TBA and MTBE, and formic acid was adsorbed on the TiO2 surface. Temperature-programmed desorption of TBA and MTBE formed 2-methyl-1-propene, water (TBA), and methanol (MTBE). During continuous-flow PCO, acetone desorbed in molar amounts equal to the amount of decomposed TBA and MTBE. The Pt/TiO2 catalysts had higher rates of complete oxidation during PCO and TPO. Injection of water during transient PCO increased the rates of oxidation of adsorbed TBA, formic acid, and acetone. Photocatalytic oxidation of TBA proceeded faster in humid air than dry air, but MTBE oxidation was less sensitive to humidity. The TiO2 catalyst was stable for MTBE, TBA, and acetone PCO at 373 K. The PCO at low conversions followed the Langmuir-Hinshelwood model.

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The dependence on temperature of gas-phase photocatalytic oxidation of methyl tert-butyl ether and tert-butyl alcohol

Catalysis Today ◽

10.1016/j.cattod.2005.03.015 ◽

2005 ◽

Vol 101 (3-4) ◽

pp. 353-358 ◽

Cited By ~ 8

Author(s):

Sergei Preis ◽

Anna Kachina ◽

Nuria Capdet Santiago ◽

Juha Kallas

Keyword(s):

Gas Phase ◽

Photocatalytic Oxidation ◽

Butyl Alcohol ◽

Methyl Tert Butyl Ether ◽

Butyl Ether ◽

Tert Butyl ◽

Tert Butyl Alcohol

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Photocatalytic oxidation of TCE and MTBE in the Gas phase

Global NEST Journal ◽

10.30955/gnj.000478 ◽

2013 ◽

Vol 10 (2) ◽

pp. 237-240

Keyword(s):

Gas Phase ◽

Photocatalytic Oxidation ◽

Methyl Tert Butyl Ether ◽

Inlet Concentration ◽

Ambient Conditions ◽

Butyl Ether ◽

Tert Butyl ◽

The Impact ◽

By Products ◽

Mtbe Decomposition

Photocatalysis is a promising method for eliminating the volatile organic compounds emitted from various industrial processes because mild or ambient conditions are used. Titanium dioxide is commonly used as photocatalyst and ultraviolet light is utilized for decomposing gas phase pollutants. In the present work, the photocatalytic oxidation of methyl tert butyl ether (MTBE) and trichloroethylene (TCE) in the gas phase was studied. The impact of residence time, TCE/MTBE concentration and oxygen concentration on TCE/MTBE conversion and byproduct formation was examined. Acetone and tert-butyl formate were detected at the reactor outlet from MTBE decomposition, whereas dichloroacetyl chloride (DCAC) and phosgene were found as by-products of TCE oxidation. The residence time affected dramatically both TCE and MTBE photo-oxidation as well as by-products existence and configuration. In contrast, the variation of oxygen inlet concentration affected significantly only MTBE conversion. Finally, the increase in MTBE and TCE inlet concentration had as a result decreased conversions observed.

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