P. Pucher

A Photocatalytic Active Adsorbent for Gas Cleaning in a Fixed Bed Reactor

Efficient photocatalysis for gas cleaning purposes requires a large accessible, illuminated active surface in a simple and compact reactor. Conventional concepts use powdered catalysts, which are nontransparent. Hence a uniform distribution of light is difficult to be attained. Our approach is based on a coarse granular, UV-A light transparent, and highly porous adsorbent that can be used in a simple fixed bed reactor. A novel sol-gel process with rapid micro mixing is used to coat a porous silica substrate with -based nanoparticles. The resulting material posses a high adsorption capacity and a photocatalytic activity under UV-A illumination (PCAA = photocatalytic active adsorbent). Its photocatalytic performance was studied on the oxidation of trichloroethylene (TCE) in a fixed bed reactor setup in continuous and discontinuous operation modes. Continuous operation resulted in a higher conversion rate due to less slip while discontinuous operation is superior for a total oxidation to due to a user-defined longer residence time.

Temperature Dependence of Single Step Hydrodeoxygenation of Liquid Phase Pyrolysis Oil

In this paper, continuous hydrodeoxygenation (HDO) of liquid phase pyrolysis (LPP) oil in lab-scale is discussed. Pyrolysis oil is derived from the bioCRACK pilot plant from BDI - BioEnergy International GmbH at the OMV refinery in Vienna/Schwechat. Three hydrodeoxygenation temperature set points at 350, 375, and 400°C were investigated. Liquid hourly space velocity (LHSV) was 0.5 h−1. Hydrodeoxygenation was performed with an in situ sulfided metal oxide catalyst. During HDO, three product phases were collected. A gaseous phase, an aqueous phase and a hydrocarbon phase. Experiment duration was 36 h at 350 and 375°C and 27.5 h at 400°C in steady state operation mode. Water content of the hydrocarbon phase was reduced to below 0.05 wt.%. The water content of the aqueous phase was between 96.9 and 99.9 wt.%, indicating effective hydrodeoxygenation. The most promising results, concerning the rate of hydrodeoxygenation, were achieved at 400°C. After 36/27.5 h of experiment, catalyst deactivation was observed.