Tar formation in a steam-O2 blown CFB gasifier and a steam blown PBFB gasifier (BabyHPR): Comparison between different on-line measurement techniques and the off-line SPA sampling and analysis method

Abstract

Keywords:Circulating fluidized bed (CFB) gasifier Pressurized bubbling fluidized bed (PBFB) gasifier BabyHPR (Heatpipe Reformer)"" Solid phase adsorption (SPA) Laser induced fluorescence spectroscopy (LIFS) On-line tar analyzer (OTA) Two on-line tar measurement campaigns were carried out using an atmospheric pressure 100 ""kW th steam-O 2 blown circulating fluidized bed (CFB) gasifier at the Delft University of Technology (TUD) and a 30-40kW th steam blown pressurized bubbling fluidized bed (PBFB) gasifier BabyHPR (Heatpipe Reformer) at the Technical University Munich (TUM). Agrol, willow and Dry Distiller's Grains with Solubles (DDGS) were used. An FID based on-line tar analyzer (OTA), an induced fluorescence spectroscopy (LIFS) based on-line laser instrument, and offline solid phase adsorption (SPA) were used to quantify tar content. In general, there was a fairly good agreement between the measured results of the 10 corresponding individual tar compounds obtained from Agrol and willow CFB and PBFB atmospheric pressure tests using the SPA and LIFS methods. The measured tar concentration difference between these two methods was less than 10%. However, a higher difference (up to 30%) was observed for fluoranthene and pyrene obtained from DDGS CFB test as well as those obtained from willow PBFB under pressure test. The total tar concentration measured by the LIFS, SPA and OTA methods varied in a comparable way with changing process parameters. Both the LIFS and OTA methods can be used as indicators to observe gasifier's performance change in real time, but a regular calibration of the OTA analyzer is required to achieve good and reliable results.

Effect of internal hydrocarbon reforming during coupled operation of a biomass gasifier with hot gas cleaning and SOFC stacks

“…The measurement of tars followed the SPA method, which was proposed by Brage et al and is used by many research groups . This method is less complex than the “tar protocol” (DIN/CEN TS 15439) and has been proven sufficient in preliminary tests and further investigations . At the Chair of Energy Systems, 100 mL of gas was sampled from the gas stream with a syringe pump (Cole‐Parmer, Model 74905‐54).…”

“…43 This method is less complex than the "tar protocol" (DIN/CEN TS 15439) and has been proven sufficient in preliminary tests and further investigations. 44,45 At the Chair of Energy Systems, 100 mL of gas was sampled from the gas stream with a syringe pump (Cole-Parmer, Model 74905-54). Adsorbable components were captured in a precooled fixed bed of 500 mg amino phase (Sigma-Aldrich Co. LLC, Supelclean LC-NH2) and stored for max.…”

Process Simulation of Dual Fluidized Bed Gasifiers Using Experimental Data

“…Online measurement of tar is possible with different techniques, such as laser spectroscopy, MS, and photoionization. However, a comparison of four online and offline methods , revealed differences of up to 50% for the tar content. Offline measurements are usually preferred for their higher levels of accuracy and wider range of species measured.…”

Infrared Spectroscopy for Online Measurement of Tars, Water, and Permanent Gases in Biomass Gasification

“…Online techniques for tar measurement include flame ionization detection (FID), photoionization detection (PID), and spectroscopic methods. 9 − 11 Analysis with FID is based on a comparison between the response of gas with and without tars. The method has some drawbacks; for instance, it is difficult to account for the decrease in gas volume because of water condensation while removing tars.…”

“…Tar measurements with LIF in gasification were made using powerful ultraviolet lasers as well as compact, low-power, light-emitting diodes. 11 While the LIF technique offers sensitive detection of low concentration levels, the signal is difficult to convert into quantitative concentrations. The signal has limited specificity for individual tar compounds as fluorescence spectra are broad and very similar for many hydrocarbons.…”