Online Characterization of Syngas Particulates Using Aerosol Mass Spectrometry in Entrained-Flow Biomass Gasification

Abstract

Entrained flow gasification is a promising technique where biomass is converted to a synthesis gas (syngas) under fuel-rich conditions. In contrast to combustion, where the fuel is converted to heat, CO 2 , and H 2 O, the syngas from gasification is rich in energetic gases such as CO and H 2 . These compounds (CO and H 2 ) represent the building blocks for further catalytic synthesis to chemicals or biofuels. Impurities in the syngas, such as particulates, need to be reduced to different levels depending on the syngas application. The objective of this work was to evaluate the amount of particulates; the particle size distribution and the particle composition from entrained flow gasification of pine stem wood at different operating conditions of the gasifier. For this purpose, online time resolved measurements were performed with a soot particle aerosol mass spectrometer (SP-AMS) and a scanning mobility particle sizer (SMPS). The main advantage of SP-AMS compared to other techniques is that the particle composition (soot, PAH, organics, and ash forming elements) can be obtained with high time resolution and thus studied as a direct effect of the gasifier-operating conditions. The results suggest that syngas particulates were essentially composed of soot at these tested process temperatures in the reactor (1200-1400 C). Furthermore, the AMS analysis showed a clear correlation between the amounts of polycyclic aromatic hydrocarbons (PAH) and soot in the raw syngas. Minimization of soot and PAH yields from entrained flow gasification of wood proved to be possible by further increasing the O 2 addition.

Influence of process parameters on the performance of an oxygen blown entrained flow biomass gasifier

“…The Pressurized Entrained flow Biomass Gasification (PEBG) pilot plant has been described elsewhere [13][14][15]. The information is therefore not repeated here, except for a minor reconstruction of the primary quench water spray, aimed at improving the conditions for slag flow at the outlet, since blocking can occur [16].…”

“…Each operating condition described in this work was operated for at least 2 h before the final samples were taken, since an earlier study showed that approximately 2 h was required to accomplish 90% of any considerable temperature change [14].…”

“…The C conv was calculated as the ratio of carbon atoms in the syngas (mol/s) over the amount of input carbon atoms from the corresponding fuel (mol/s) as previously defined by Weiland et al [13][14][15]. The carbon mass balance also included the solids captured in the quench water.…”

“…Earlier work performed by us has been focused on a detailed characterization of the gasifier with respect to product gas composition (gaseous and particulate compounds), mass and energy balance, ash related operational problems for different types of solid fuels [12][13][14][15][16][17][18][19] and pyrolysis oil [20]. However, no systematic variation of process parameters has been done in earlier work in order to establish knowledge about the response of the gasifier to different operating conditions.…”

Multiscale Reactor Network Simulation of an Entrained Flow Biomass Gasifier: Model Description and Validation

“…The PEBG pilot plant at SP ETC in Piteå, Sweden was used as a reference in the validation process of the developed ERN model. A brief description of the experimental setup is provided here.…”