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QUAREC

QUAREC Information

 
General information
Access mode Physical access
Infrastructure name and acronym Quartz Reactor (QUAREC)
Photos   
Location Wuppertal, Germany
Website

http://www.ptc.uni-wuppertal.de/forschung/atmosphaerenchemie.html;

http://www.ptc.uni-wuppertal.de/forschung/atmosphaerenchemie/laborstudien.html
Legal name of organisation operating the infrastructure Bergische Universität Wuppertal
Description of the infrastructure
Brief general description of the infrastructure to which access is offered

The QUAREC reactor consists of two quartz cylinders with an inner diameter of 0.47 m and a total joined length of 6.2 m. The chamber is closed at both ends by aluminium flanges which contain numerous inlet and outlet ports for the introduction of bath gases and chemicals. A pumping system consisting of a turbo-molecular pump backed by a double stage rotary fore pump allows the photoreactor to be evacuated to 10-3 Torr. Magnetically coupled Teflon mixing fans are mounted inside the chamber to ensure homogeneous mixing of the reactants. 
Two types of lamps are available for photolysis of the radical/atom precursors: 32 super actinic fluorescent lamps (Philips TL 05/40 W: 320<λ<480 nm, λmax=360 nm) and 32 low-pressure mercury lamps (Philips TUV/40W, λmax=254 nm). The lamps are distributed evenly around the photoreactor, are wired in parallel, and can be switched individually. 
A White type multiple-reflection mirror system with a total optical path length of 484.7 ± 0.8 m is mounted inside the photoreactor for sensitive in situ long path absorption monitoring of reactants and products in the IR spectral range 4000 – 700 cm-1. IR spectra are generally recorded with a spectral resolution of 1 cm-1 using a Nicolet Nexus FT-IR spectrometer equipped with a KBr beam splitter and a liquid nitrogen cooled mercury-cadmium-telluride (MCT) detector.
The reactor can be temperature regulated with a precision of ± 1K in the temperature range 262 – 312 K
Apart from FTIR spectrometry a GC-MS system will be available for reactant and product analysis from the middle of 2016. Monitors for the detection of NOx, O3 and HONO are also available and can be attached to the reactor.

Services currently offered by the infrastructure and its research environment Investigations of gas-phase photooxidation processes including:
- Determination of rate coefficients for the reactions of OH, NO3 halogens and ozone with VOCs
- Product analysis of the radical or ozone mediated photooxidation of VOCs 
- Help in the elucidation of VOC degradation mechanisms
Modalities of access and support offered under EUROCHAMP-2020
Typical duration of work

Two to three weeks

Community/user type served

QUAREC is mainly used for research projects

Scientific and technical support offered

Guidance in the planning and assistance in performing and evaluating the experiments performed in QUAREC. A technician is permanently on site to ensure the smooth operation of the facility.

Logistic and administrative support offered

Assistance is given with the bath gases necessary for the experiments and also the ordering of chemicals (if desired). If requested assistance in finding accommodation for the duration of the TNA will be provided.

Person in charge of access provision at the infrastructure

Prof. Peter Wiesen (wiesen@uni-wuppertal.de) or Dr. Ian Barnes (barnes@uni-wuppertal.de

Extended technical information
Physical description  The QUAREC chamber is made of 2 quartz glass tubes with metal end flanges
Volume: 1080 litres (1.08 m3)
Diameter: 0.47 m
Length: 6.2 m
Total Surface Area: 9.5 m2
Lateral Surface Area: 9.15 m2
End Flange Surface Area: 2 x 0.173 m2
Surface-to Volume Ratio: 8.79 m-1
Mechanical description (schematic)   
Mechanical description Limited mechanical information is available on request 
Irradiation spectra   
Auxiliary mechanism 

 Process                                                Nominal Rate                    Comment                    

hn + wall = OH                                     (1 106 molecule cm-3)           Not accurately known                                                               

hn + wall = NO                                     1-10 10-7 molecules s-1         Highly variable                                                                          

NO2 = 0.5HONO + 0.5wHNO3             5.2 10-5 s-1                             QUAREC characterisation

wHNO3 + hn = OH + NO2                    J(HNO3)                                 Not yet known                                                                          

N2O5 = 2 wHNO3                                  2.35 10-4                                QUAREC characterisation

N2O5 + H20 = 2 wHNO3                        6.5 10-20 cm3 s-1                     Literature IUPAC                                                                     

O3 = wO3                                               3.2 10-5 s-1                            QUAREC characterisation

HNO3 = wHNO3                                    3-6 10-5 s-1                             QUAREC characterisation

Initial HONO                                                                                       Not yet known but low                                                             

J(NO2)                                                   3.52 10-3 s-1                           Spectral radiometer                                                               

J(HCHO)                                               3.70 10-6 s-1                           Spectral radiometer                                                                

 J(HONO)                                                6.80  10-4 s-1                          Spectral radiometer

 

Description paper

I. Barnes, K.H. Becker and N. Mihalopoulos, An FTIR Product Study of the Photooxidation of Dimethyl Disulfide.
J. Atmos. Chem. 18 (1994)267-289.