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Methodology for Sampling and Characterizing Internally Mixed Soot-Tar Particles Suspended in the Product Gas from Biomass Gasification Processes

Malik, Azhar LU ; Nilsson, Patrik LU ; Pagels, Joakim LU ; Lindskog, Magnus LU ; Rissler, Jenny LU ; Gudmundsson, Anders LU ; Bohgard, Mats LU and Sanati, Mehri LU (2011) In Energy & Fuels 25(4). p.1751-1758
Abstract
When biomass is used to produce fuels and green products by thermochemical conversion, the ability to handle or remove the fine particle phase in the product gas is crucial. The product gas from biomass gasification contains relatively volatile organic compounds (“tar”) condensed on nonvolatile cores of, for example, aggregated soot particles and char. The problems are, for example, that particles will poison catalysts used for upgrading of the gas and loss of thermal energy occurs when carbonaceous particles are being formed. The aim of the work is to design and use novel methodologies to characterize the particles in the product gas stream. A methodology has been developed to sample and characterize fine particles by a sampling probe... (More)
When biomass is used to produce fuels and green products by thermochemical conversion, the ability to handle or remove the fine particle phase in the product gas is crucial. The product gas from biomass gasification contains relatively volatile organic compounds (“tar”) condensed on nonvolatile cores of, for example, aggregated soot particles and char. The problems are, for example, that particles will poison catalysts used for upgrading of the gas and loss of thermal energy occurs when carbonaceous particles are being formed. The aim of the work is to design and use novel methodologies to characterize the particles in the product gas stream. A methodology has been developed to sample and characterize fine particles by a sampling probe connected to either a denuder or a packed bed device. The system was designed to avoid condensation of organic compounds when diluting the sample and decreasing the temperature. A flame soot generator connected to a condensation−evaporation unit was used to produce internally mixed model particles, i.e., particles consisting of a core of soot with an outer layer of condensed volatile compounds. A scanning mobility particle sizer (SMPS) and a differential mobility analyzer followed by an aerosol particle mass analyzer (APM) were used to characterize the particles. Because of the agglomerated structure of soot, the SMPS system was not adequate to fully characterize the mass of volatiles condensed onto the soot core, and therefore the DMA-heater-APM technique was used to determine the mass fraction of the condensed phase on the soot particles. The two different configurations were studied, and the sampling system was shown to work at a high load of organic mass. In both cases, the organic removal efficiency was >99.5%. Minor condensation of organics on the sampled soot was found for the denuder but not the packed bed. On the other hand, the particle losses were substantially higher for the packed bed compared to the denuder. The results showed that the tested sampling methodology can be used to get sufficient characterization of particles in the product gas and to evaluate the performance of biomass product gas cleaning systems at high temperature. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
soot particles, tar, high temperature sampling, gasification, gas cleaning system, product gas, APM, aerosol
in
Energy & Fuels
volume
25
issue
4
pages
1751 - 1758
publisher
The American Chemical Society
external identifiers
  • wos:000289697700046
  • scopus:79955403812
ISSN
0887-0624
DOI
10.1021/ef101426v
language
English
LU publication?
yes
id
1ed4ddb9-2108-4e0d-8f74-2b1f072f86d1 (old id 1951436)
date added to LUP
2011-05-12 15:13:43
date last changed
2017-09-10 04:56:48
@article{1ed4ddb9-2108-4e0d-8f74-2b1f072f86d1,
  abstract     = {When biomass is used to produce fuels and green products by thermochemical conversion, the ability to handle or remove the fine particle phase in the product gas is crucial. The product gas from biomass gasification contains relatively volatile organic compounds (“tar”) condensed on nonvolatile cores of, for example, aggregated soot particles and char. The problems are, for example, that particles will poison catalysts used for upgrading of the gas and loss of thermal energy occurs when carbonaceous particles are being formed. The aim of the work is to design and use novel methodologies to characterize the particles in the product gas stream. A methodology has been developed to sample and characterize fine particles by a sampling probe connected to either a denuder or a packed bed device. The system was designed to avoid condensation of organic compounds when diluting the sample and decreasing the temperature. A flame soot generator connected to a condensation−evaporation unit was used to produce internally mixed model particles, i.e., particles consisting of a core of soot with an outer layer of condensed volatile compounds. A scanning mobility particle sizer (SMPS) and a differential mobility analyzer followed by an aerosol particle mass analyzer (APM) were used to characterize the particles. Because of the agglomerated structure of soot, the SMPS system was not adequate to fully characterize the mass of volatiles condensed onto the soot core, and therefore the DMA-heater-APM technique was used to determine the mass fraction of the condensed phase on the soot particles. The two different configurations were studied, and the sampling system was shown to work at a high load of organic mass. In both cases, the organic removal efficiency was >99.5%. Minor condensation of organics on the sampled soot was found for the denuder but not the packed bed. On the other hand, the particle losses were substantially higher for the packed bed compared to the denuder. The results showed that the tested sampling methodology can be used to get sufficient characterization of particles in the product gas and to evaluate the performance of biomass product gas cleaning systems at high temperature.},
  author       = {Malik, Azhar and Nilsson, Patrik and Pagels, Joakim and Lindskog, Magnus and Rissler, Jenny and Gudmundsson, Anders and Bohgard, Mats and Sanati, Mehri},
  issn         = {0887-0624},
  keyword      = {soot particles,tar,high temperature sampling,gasification,gas cleaning system,product gas,APM,aerosol},
  language     = {eng},
  number       = {4},
  pages        = {1751--1758},
  publisher    = {The American Chemical Society},
  series       = {Energy & Fuels},
  title        = {Methodology for Sampling and Characterizing Internally Mixed Soot-Tar Particles Suspended in the Product Gas from Biomass Gasification Processes},
  url          = {http://dx.doi.org/10.1021/ef101426v},
  volume       = {25},
  year         = {2011},
}