Manual tar measurement method, phase 2

The aim of the project is to: verify the final choice of solvent for 'Guideline for Sampling and Analysis of Tar and Particles in Biomass Producer Gas' and to develop an unambiguous method for tar evaporation with the chosen solvent; verify the sampling efficiency of Danish Technological Institute's recently developed two stage sampling train in order to achieve international approval (inclusion in 'Guideline'); examine suitable filter systems and sampling temperature by measuring tar in cocurrent gas and/or in gasification gas with a high dust content; disseminate know-how on the new tar measurement method. Future measurements shall exclusively be based on isopropanol which is our preferred solvent on the recently developed two stage sampling train. Due to the faet that they have influence on the sampling efficiency, the following variable sampling parameters shall be examined methodically: 1) Temperature of solvent (cooling of sampling train); 2) Under pressure in sampling train; 3) Sampling volume flow (litre/min.). 'Guideline' recommend up to 10 Iitre/min. which we have not yet obtained; 4) Sampling volume/time (tar concentration in solvent); 5) Tar concentration in the gas. The sampling shall be carried out in counter current and cocurrent raw gas where the tar penetration is measured for each variable by means of a backup-system coupled in series (includes tests with online measurements with MIMS). In cocurrent gas and in gas with a large content of particulates, a particulate filter shall be placed in front of the tar collection system. The examination is solely based on quarts fibre thimble. The following examinations have not yet been carried out: 1) Filter temperature (heating on sampling probe and filter housing); 2)Sampling volume flow (litre/min.); 3) Sampling volume/time (particulate load of the filter vs. pressure loss). Furthermore, it shall be examined whether evaporation of small subsets of a test leads to reproducible results. In addition, a 'Round Robin-tests' for GC tar and for gravimetric tar must be carried out. Denmark will take the initiative