Real-Time Monitoring of Trace Gas Concentrations in Syngas

Abstract

Re´sume´-Suivi en temps re´el des concentrations de gaz traceurs dans un extrait de gaz de synthe`seUn spectrome`tre de masse par re´action de transfert de protons (PTR-MS, Proton Transfer Reaction -Mass Spectrometer) a e´te´utilise´pour l'analyse de gaz de synthe`se dans un proce´deí ndustriel Fischer-Tropsch. Un PTR-MS peut de´tecter une grande varie´te´de compose´s organiques et inorganiques volatils en temps re´el et avec une sensibilite´e´leve´e. Associe´a`un multiplexeur, il permet un suivi en ligne (en temps re´el) des contaminants a`l'e´tat de traces a`diffe´rents stades d'un proce´de´Fischer-Tropsch. Plusieurs compose´s volatils, tels que HCN, H 2 S, RSH, des carbonyles, des acides, des alcools et autres, ont e´te´mesure´s dans du gaz de synthe`se. Cet article de´crit la configuration pour le suivi du gaz de synthe`se en utilisant le PTR-MS et re´sume le re´sultat de ce projet de preuve de concept.Abstract -Real-Time Monitoring of Trace Gas Concentrations in Syngas -A Proton Transfer Reaction Mass Spectrometer (PTR-MS) was used for the analysis of syngas in an industrial Fischer-Tropsch process. A PTR-MS can detect a variety of volatile organic and inorganic compounds in real-time and with high sensitivity. Together with a multiplexer, this allows for online (real-time) monitoring of the trace contaminations at different stages of a Fischer-Tropsch process. Several volatile compounds, such as HCN, H 2 S, RSH, carbonyls, acids, alcohols and others have been measured in syngas. This paper describes the setup to monitor syngas using PTR-MS and summarizes the result of this proof-of-principle project.

Elucidation of artefacts in proton transfer reaction time‐of‐flight mass spectrometers

“…[13][14][15][16] However, reports on industrial or catalytic applications are scarce. [17][18][19] One of the main advantages of PTR-MS is the rather "soft" ionization of molecules by the primary ion H 3 O + , such that the proton transfer can be considered to be almost nondissociative but there are some exceptions (alcohols 20 and terpenes 21 ). Because of the low fragmentation, this technique allows the detection of molecules at their molecular mass plus one H + , and thus, it enables the analysis of complex gas mixtures without the need for previous separation methods.…”

Determination of trace compounds and artifacts in nitrogen background measurements by proton transfer reaction time‐of‐flight mass spectrometry under dry and humid conditions

“…PTR-MS was developed to determine VOCs in air and has found application in a variety of fields such as breath analysis, 19,20 environmental science, 18,[21][22][23] life 18,20 and food science, [24][25][26] process monitoring, [27][28][29][30] and studies on industrial or catalytic applications. [31][32][33][34][35][36][37][38][39][40] The main advantage of PTR-MS is its soft ionization of molecules by the primary ion H 3 O + , which implies that the ionmolecule process during the PTR is almost nondissociative. This low fragmentation can be used for the detection of molecules at their molecular mass plus one H + , and thus, it enables the analysis of complex gas mixtures without the need for previous separation methods.…”

“…Sometimes, even sample preconcentration is necessary 51 in order to increase the sensitivity of the method 52 . However, for the characterization of VOCs in industrial gases, dilution becomes necessary to avoid pressure changes in the detection region of the instrument and to prevent saturation of the detector, thus remain in the linearity range of the detector 31 . To avoid detector saturation in the analysis of industrial gases without losing too much sensitivity is challenging, because the concentration range of many compounds of interest may be quite different and often exhibit significant temporal fluctuations.…”

“…This technique is a powerful tool for the on‐line monitoring of trace amounts of VOCs without requiring additional preseparation techniques such as GC. PTR‐MS was developed to determine VOCs in air and has found application in a variety of fields such as breath analysis, 19,20 environmental science, 18,21–23 life 18,20 and food science, 24–26 process monitoring, 27–30 and studies on industrial or catalytic applications 31–40 . The main advantage of PTR‐MS is its soft ionization of molecules by the primary ion H 3 O + , which implies that the ion‐molecule process during the PTR is almost nondissociative.…”

Direct Analysis Mass Spectrometry

“…Different platforms have been utilized including field site measurements [67,68], vehicles [69], ships [70], and aircraft [71][72][73]. Some of these variations in the applications of PTR-MS are demonstrated in the snap shot of publications that follow: (i) measurements of VOCs of anthropogenic origin above a large city [69]; (ii) analysis of syngas in an industrial Fischer Tropsch process [74]; (iii) a comparison of PTR-MS with GC-MS of environmental analytes [75]; (iv) monitoring the atmosphere for pollutants near intensive farm animal production [76].…”