Alex De Visscher, Department of Chemical and Petroleum Engineering, University of Calgary
2010
Executive Summary
This report summarizes the activities carried out in the period August 2009-June 2010. Laboratory experiments on toluene and benzene photolysis in waste gas were carried out. The results indicate that up to 2 mg/min of toluene can be degraded with 80 % efficiency with a 40 W lamp. At 7 cents/kWh, this amounts to a $25,000 annual electricity cost to eliminate 1 ton BTEX/year. For benzene, the efficiency at a flow rate of 2 mg/min is about 60 %. An incomplete but functional simulation model involving 33 reactions and 37 chemical species was developed for benzene photolysis. The results were very similar to the experimental results for toluene but overestimated the benzene efficiencies. When ozone was added as a reagent, the efficiency predicted by the model increased dramatically. If correct, this means that the energy cost of destroying 1 ton of benzene can be reduced to $8,000 per tonne. Given that the benzene degradation efficiency is somewhat less than predicted in the absence of ozone, the cost maybe somewhat above this estimate. A simple condensation model for BTEX was developed. The model indicates that variability of the feed increases the average condensation efficiency, as hypothesised, but only strong variabilities lead to a pronounced effect. In Year 2 we plan to continue the experimental work and the model development. The effect of pre-mixing ozone will be given special attention. Condensation modeling will be continued as well. The condensation work will be planned further in consultation with the project manager.