Online tar analysis with laser mass-spectrometry for biomass gasifiers

Abstract

The further development of gasification technology for biomass for various sizes of gasifiers and differrent end uses needs detailed information about the product gas com-position. This is especially the case for unwanted by-products like tar. An online analysis system is applied making use of a combination of gas chromatogra-phy (GC) and laser mass spectrometry (LAMS). A conventional tabletop gas chromatograph/ion-trap mass-spectrometer (GC/MS) system (Varian Saturn) was equipped with an additional laser ionization (LI) system. Its applicattion reduces fragmentation of analyte molecules and allows for short analysis times even in complex hydroocarbon matrices. The application of GC/LAMS for tar analysis in biomass gasification provides results in much shorter time compared with other tar analysis methods. The analysis system is set up for carrying out fundamental research on gasification processes mainly at laboratory sites. Its flexible design offers the possibilities of using electron impact (EI) as well as laser ionization in mass spectrometry, being able to perform hot-gas online and liquid offline analyses with the option of gas chroma-tographic separation. It was made mobile to perform field measurements on larger, technical-scale gasifiers as well.