4.3.2. Halides

The content of chlorine species present in syngas was measured with the use of two methods. The direct measurement from syngas was done through adsorption in NaOH performed with a set-up similar to the above-mentioned water/tar/particle measurement. The samples were analyzed with the use of ion chromatography. Due to Cl content in the gas, which is only marginally above the detection limit of the method, the measurement was done in parallel for raw gas after the reactor, as well as after the water condensation and demisting steps, to assure no Cl was present in syngas after the last stage of syngas cleaning. As an indirect measurement, the measurement of Cl content in the water condensate from the gas cooler was also done. A baseline for gasification of the biomass was detected for a scenario when the gas cleaning was performed without the use of any sorbents or pre-coats. Any result of chlorine ion content in the condensate lower than the baseline indicates that HCl was removed from syngas in the prior adsorption/filtration step.

For chromatography, a dual-channel reagent-free capillary Dionex ICS-5000 ion chromatograph was used. The set-up consisted of dual ion chromatography (IC) channels, each connected to an individual gradient pump, eluent generator cartridge, injection valve, column set, and detector, while

an autosampler was also used. A Chromeleon ® 6.7 (Dionex) Data Management system was used for instrument control and data handling.

For separation and analysis of cations, the IonPack CS-16 analytical column (250 mm × 3 mm) and IonPack CG-16 guard column were applied. An external standard method using a commercial six-cation solution was utilized for quantitative analysis. Furthermore, 40 mM methanesulfonic acid eluent of high purity was electrochemically produced by the eluent generator cartridge (EGC-MSA). The eluent flow was maintained at a rate of 0.340 mL/min. The column and detector compartments were thermostated at 30 ◦C and 20 ◦C, respectively, to obtain constant conditions. Chromatograms were recorded isocratically for 30 min.
