E!113720 Multi-Gas Sensing enabled by Meta-surfaces

Optimization of industrial processes and reducing air pollution stemming from them is a more and more important quest to increase process efficiencies, protect the environment and assure peoples’ health throughout Europe and the world. Tunable diode laser absorption spectroscopy (TDLAS) has become a well-accepted technology for in-situ gas concentration measurements of processes in all kinds of industries. While powerful, TDLAS is typically limited to only one gas per instrument. This leads to a high capital investment for customers since two analysers must be put into place if two gases need to be monitored simultaneously. It is therefore desirable to combine the two analyzers in a single compact unit. The primary objective of this project was to overcome the need for installing several analysers and develop a concept enabling true multi-gas sensing with one laser module. A Fluidic Catalytic Converter Unit (FCCU) was selected as test application. Here, the components oxygen, carbon monoxide and carbon dioxide need to be measured for proper process control and process safety. Project partner Nanoplus developed a new device that is able to spatially combine up to three single mode infrared laser beams whose emission lines are further separated than what can be realized with a single laser chip. It was considered to use metasurfaces and micro-optics to enable beam shaping in a compact and novel way for this application to develop a compact laser module. The envisioned meta-optic lens was designed to impose focusing phase profiles with equal focal length onto incident light fields at two or three different frequencies. Prototype metasurfaces were realized using resonant nanostructures on an IR-transparent substrate, whose structural parameters vary as a function of the in-plane position to locally adjust the phase of the transmitted light to the desired value. NEO Monitors developed electronics able to address up to three lasers and detectors in a new set of PCBs. The multi-laser device from Nanoplus was assessed in a laboratory environment. Special emphasis was on the noise properties as this is a crucial indicator of the overall performance. The results were promising as the noise level of the multi-laser device was meeting the requirements of the targeted FCCU application.

The developed components and concepts of the project will have a significant effect on NEOM's Sales since it entails a shift in technology as well as in market approach. The Sales will be moving from single gas analyzer towards complete application analyzers. A significant financial impact is expected since profit margins are typically higher. The new analyzers using developments and knowhow gained during the project will have a positive impact on process efficiencies that lead to an economical advantage for NEOM's customers. Last but not least, with better process control, the generation and thus emission of pollutants will be limited leading to cleaner emissions.

Optimization of industrial processes and reducing air pollution stemming from them is a more and more important quest to increase process efficiencies, protect the environment and assure peoples’ health throughout Europe and the world. Tunable diode laser absorption spectroscopy (TDLAS) has become a well-accepted technology for in-situ gas concentration measurements of processes in all kinds of industries. While powerful, TDLAS is typically limited to only one gas per instrument. This leads to a high a capacity extension invest for customers since two analysers must be put into place if two gases need to be monitored simultaneously. It is therefore desirable to combine the two analyzers in a single compact unit. The aim of this project is to overcome the need for installing several analysers and develop a concept enabling true multi-gas sensing with one laser module. The new device is able to spatially combine up to three single mode infrared laser beams whose emission lines are further separated than what can be realized with a single laser chip. For this, metasurfaces and micro-optics will be used to enable beam shaping in a compact and novel way for this application to develop a compact laser module. The envisioned meta-optic lens will be designed to impose focussing phase profiles with equal focal length onto incident light fields at two or three different frequencies. This shall be realized using resonant nanostructures on an IR-transparent substrate, whose structural parameters vary as a function of the in-plane position to locally adjust the phase of the transmitted light to the desired value. This enables the use of the best suited absorption lines for the targeted applications and is the core of the development of this project. It is expected that the optical system of the analyser can be reduced by at least 50% due to the implementation of the novel light source. The performance of the final analyzer will be demonstrated in a field-application test.