Monitoring of Gasification Processes

Background

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Gasification of carbonaceous material such as biomass and charcoal is a major source for the production of syngas. For the monitoring of gasification processes robust analytical instrumentation is needed that provides information in real time. Typical tasks comprise quantification of the resulting syngas components as well as leak detection and determination of possible contaminants which may cause degradation of catalysts used for fuel synthesis or induce saturation of the gas cleaning systems. In biomass gasification applications the contaminants are called tar and include BTX (benzene, toluene, xylene) and PAH (polycyclic aromatic hydrocarbons). Moreover, several inorganic impurities such as H2S and COS may be present.

Solution

V&F IMR Mass Spectrometers (Ion Molecule Reaction) are capable of quickly identifying and determining organic and inorganic contaminants in syngas from biomass gasification processes. Due to a wide dynamic measuring range the IMR technology is suited for measurements of concentrated tars at the exhaust of a fluidized bed reactor as well as for measurements of tar traces in the tar cracker exhaust (gas reformer exhaust). In addition, sulfur compounds such as thiophene, H2S and COS can be determined with excellent selectivity within the same method. Results are obtained in real time allowing for detailed studies of tar behavior during gasification processes.

Quantification of the syngas components (H2, CO, CO2) and combustibles e.g. methane from subsequent conversion reactions like the Fischer-Tropsch synthesis can be done with the V&F EISense Mass Spectrometer. It features the proven Electron Impact (EI) ionization technology and is frequently used for monitoring of combustion, fermentation and gas synthesis processes. Another field of application is the process leak detection where O2 and N2 are detected in the Vol% range. V&F mass spectrometers can be equipped with a variety of interfaces to ensure proper embedding into automation systems such as ProfiBus environments. Alternatively, they can be operated as a standalone unit with the user friendly V&F Viewer software.

Advantage

Common analytical techniques applied to gasification processes especially for contaminant monitoring include micro gas chromatography (µGC) and solid phase adsorption (SPA) followed by offline Gas Chromatography (GC). A µGC method usually takes a few minutes to yield a result and detection limits are in the ppmv range whereas IMR-MS provides multiple data points per minute and features detection limits of a few ppbv for important tar components such as BTX. SPA methods are not suited for detailed studies of contaminant behavior as they rely on lengthy sample taking procedures and involve offline GC analysis.

V&F mass spectrometers enable the operator to quickly adapt the instrument to new measurement routines or to expand current measurement setups by adding new compounds of interest within a few minutes. A compact and rugged design aids their mobility and a change of the measurement site can easily be realized within a working day.

Highlights

  • Real time measurement of contaminants in biomass gasification
  • H2, CO, CO2 quantification in charcoal gasification
  • High sensitivity and high selectivity

Reference customers (excerpt)

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Applicable instruments

EISense
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AirSense
CombiSense