DURREC
DURREC (DURan glass REaCtor) is an evacuable reaction chamber deployed to study homogeneous gas phase reaction systems under room temperature conditions, and recording calibrated IR and UV gas spectra of target compounds.
It consists of a borosilicate glass cylinder (45 cm diameter and 3 m length) sealed at both ends by aluminium flanges. On the one end, there are various ports mounted, for injection of chemicals, monitoring of physical parameters and other potential experimental design purposes. The reactor has a total volume of 0.48 m3 and an inner surface of 4.9 m2. The homogeneity of the gas mixtures is achieved with 1 Teflon® fan (magnetic drive coupling) placed on the front flange. The reactor body is surrounded by an irradiation system, encased in a high-reflectivity metal sheet made box, cooled with air. The ports mounted on the front flange allow for concurrently on-line coupling of several analytical monitors.
Operation and cleaning of the reaction chamber follow routine schedules. However, observing certain physical limitations, these are suitable to changes as demanded by experimental design.
DURREC is operated under dry conditions, atmospheric pressure and 298±2 K. As bath gases, synthetic air or N2 (high purity, Linde) might be used.
DURREC is cleaned after every experiment by repeating cycles of pumping down and flushing with ca. 200 mbar bath gas until complete disappearance of spectral features in the chamber. A dismantling of the chamber and manually cleaning of the glass cylinder and the components it contains (mirrors for the UV and IR couplings, fans, ports and joints, etc.) is performed once a year or often, if the quality of the IR spectra or other analytical signals (monitors) demands it.
The reactor is surrounded by 32 evenly placed connector slots to accommodate lamps with different wavelengths above 300 nm, which can be switched on individually, according to the desired type of experiment.
For cleaning purposes, the reactor is served by a rotary vane pump and a root pump, yielding an end vacuum of up to 10−3 mbar.
DURREC features two in-situ multiple reflexion mirror systems, one for the mid-IR and one for the UV range. Permanently, only an FTIR instrument (Nicolet 6700) is coupled with the ASC (active path way 51 ± 0.2 m).
A choice of on-line (mobile) instrumentation is available which can be coupled to any of the three atmospheric simulation chambers according to the desired experimental design.
