The project aims to provide the technical basis for the application of photocatalytic oxidation processes to accomplish the complete destruction of volatile and semivolatile persistent organic toxic and hazardous pollutants in gaseous emissions.
More explicitly, the objectives are : a) to demonstrate the feasibility of the process to treat waste stream VOC concentrations in the range 10 - 10000 ppm for organic pollutants (e.g. toluene, xylenes, naftalene, TCE) b) to develop monolithic catalysts (honeycomb structures) including matrix design, manufacture and active phases selection c) to optimize photoreactor configuration and performance using theoretical models, with prediction of energy efficiency and chemical conversion d) to determine the technical and engineering boundary conditions by means of furnace-scale tests.
1st phase: Gas-phase photocatalytic detoxification with Xenon lamp
The aims of this first phase are to define an useful catalyst to destroy the VOC, and to identify and determine the characteristic parameters of the chemical reactions with lab-scale tests, as well as analytical and engineering systems associated to the process.
* GAS-solid heterogeneous photocatalytic tests :
In an experimental photoreactor, activity tests at lab scale will be carried out, with and without catalyst monoliths, to measure the photodegradability of the molecules at different conditions.
* Catalytic monoliths development :
Monoliths with different active phases (based on TiO2, V2O5, CuO and other semiconductors) will be prepared, characterized and tested in the photoreactor with different model VOCs.
* Numerical model of photoreactor performance
As a result of the computer modelling, detailed profiles of the solid- and gas-phase temperatures, fluid compositions, chemical reaction rates and chemical energy conversion as functions of position in the catalyst will be proposed.
2nd phase; Detoxification of VOC waste streams at engineering-scale
In this second phase a solar powered furnace will be used for engineering-scale tests. Methodology is similar to that described within phase 1. Specific operational and scale up problems influencing the final efficiency of the process will be studied such as photon flux daily variation, start-up and close-down.
With results and experiences coming from phases 1 and 2, the final feasibility of this technology can be assessed. A pre-industrial application would be suggested as a straightforward continuation of the project.
Funding SchemeCSC - Cost-sharing contracts