The SAFESIDE project started in January 2017. A website dedicated to this project has been put online: http://www.safeside-project.eu. The aim of the SAFESIDE project was to develop new gas measurement tools in order to help with better management and risk assessment in the field in the event of an incident. Among the gases identified, we selected in particular Ammonia, CO, CO2 , HCl, HCN, SO2 and NOx. The creation of a low-cost, portable system capable of identifying at least 5 of these gases in relatively low concentrations (below ERPG2 threshold) would be a particularly useful tool for defining the levels of danger and safety perimeters. This is the orientation that was given to the project.
Different approaches have been studied in SAFESIDE by combining the know-how of the different partners:
– the ability to produce lasers on semiconductor chips at the University of Ghent (UGAND),
– the expertise in fiber laser sources at MULTITEL,
– the availability of field measurement tools and the development of multipass cells at the University of Dunkirk (ULCO),
– knowledge of spectroscopic measurement methods and design of photo-acoustic detectors at the University of Reims (URCA),
– the availability of test infrastructures and good knowledge of risk prevention needs at the University of Mons (UMONS)
By combining these different areas of expertise, we have produced different systems that we have validated in the laboratory and in the field:
– Lasers tunable in wavelength and integrated on chip, combined with multipass cells for measurements of NH3, CH4 and CO2 in the laboratory.
– Multipass cells combined with different laser sources (QCL, diodes) for laboratory and field measurements of NH3 and CO2.
– Tunable laser system in the mid-infrared (OPO), delivering high power signals making possible to carry out measurements on different gases in the laboratory and in the field, using different strategies: sampling by a suction tube and measurement in free space through of a gas cloud.
The main measurement results obtained on different gases, with the same tunable laser, are the followings:
– CO2, min detection of 400ppm (<< ERPG2)
– NH3, min detection of 85ppm (< ERPG2, 130ppm)
– HCl, detection min of 30ppm (~ ERPG2, 33ppm)
– CH4 measurement (~ 100ppm)
– Measurement of Acetone (~1%), …
The developed multipass cells can be very easily associated with specific laser diodes to target a particular gas. Such system can be integrated into the CCM mobile laboratory at the University of Dunkirk, as we have done for experiments on the field.
The laser with OPO allows, thanks to its tunability in wavelength, to address several molecules with the same system. In combination with the rapid modulation of the laser, it is possible to settle its wavelength at a characteristic absorption peak of a targeted molecule and to quickly scan a few lines around this position. Finally, measurements can be made in free space or by sampling using a single-passage, multi-passage or photo-acoustic cell. This new system could eventually become a very flexible tool that can be deployed in the field or for the permanent monitoring of a risk zone in an industrial installation, for example.
Pictures of the on-field experiments performed on NH3 gas release through the gas cloud (like a 10m optical fence)
Pictures of the on-field experiments performed on CO2 gas release based on sampling method (100m suction tube from field to the mobile lab)
More detailed information can be found in the public project report: Rapport public-EN
