Wood Gas Processing To Generate Pure Hydrogen Suitable for PEM Fuel Cells

Self Cite

Interaction of biomass ash and bed materials in thermochemical conversion in fluidized beds leads to changes of the bed particle surface due to ash layer formation. Ash components present on the bed particle surface strongly depend on the ash composition of the fuel. Thus, the residual biomass used has a strong influence on the surface changes on bed particles in fluidized bed conversion processes and, therefore, on the catalytic performance of the bed material layers. Ash layer formation is associated with an increase in the catalytic activity of the bed particles in gasification and plays a key role in the operability of different biomass fuels. The catalytic activation over time was observed for K-feldspar used as the bed material with bark, chicken manure, and a mixture of bark and chicken manure as fuels. The changes on the bed material surfaces were further characterized by SEM/ EDS and BET analyses. Raman, XPS, and XRD analyses were used to characterize the crystal phases on the bed material surface. An increase in surface area over time was observed for K-feldspar during the interaction with biomass ash. Additionally, a more inhomogeneous surface composition for fuels containing chicken manure in comparison to pure bark was observed. This was due to the active participation of phosphorus from the fuel ash in the ash transformation reactions leading to their presence on the particle surface. A decreased catalytic activity was observed for the same BET surface area compared to bark combustion, caused by the different fuel ash composition of chicken manure.

Section: Introductionmentioning

confidence: 99%

Impact of residual fuel ash layers on the catalytic activation of K-feldspar regarding the water–gas shift reaction

Fürsatz

Kuba

Janisch

et al. 2020

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“…As a consequence, the product gas from this specific gasification is practically free of nitrogen and can be further used as a valuable synthesis gas for the production of a variety of different end products [2]. Examples of such products are bio-methane [3,4], Fischer-Tropsch bio-diesel [5,6], pure hydrogen [7][8][9], or mixed alcohols [10]. Therefore, this technology is also referred to as polygeneration.…”

Section: Introductionmentioning

confidence: 99%

Influence of coated olivine on the conversion of intermediate products from decomposition of biomass tars during gasification

Kuba

Kirnbauer

Hofbauer

2016

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Steam gasification of solid biomass in dual fluidized bed systems is a suitable technology for the production of chemicals, fuels for transportation, electricity, and district heating. Interaction between biomass ash and bed material leads to the development of Ca-rich bed particle layers. Furthermore, incomplete decomposition of biomass leads to the formation of tar components; among these are stable intermediate products such as 1H-indene and stable gaseous hydrocarbons such as methane. In this work, the influence of bed particle layers on the conversion of intermediate products such as 1H-indene and methane via steam reforming was investigated by conducting experiments in a lab-scale test rig. Satisfying conversion of 1H-indene into gaseous molecules (e.g., CO, CO 2 , H 2 ) was achieved with used, layered olivine, whereas fresh olivine showed significantly poorer performance. Since steam reforming was connected to the watergas-shift reaction for the tested hydrocarbons, investigations regarding carbon monoxide conversion in the presence of steam were conducted as well. Furthermore, a comparison of the influence of fresh and used bed material concerning the conversion of methane is presented, showing that methane is not affected by the bed material, independent of the presence of particle layers.

“…Table 1 Operating conditions at the extraction point (see Fig. 1) of the CHP plant in Oberwart, Austria, at full load operation [6] Parameter Before RME scrubber Units…”

Section: The Water Gas Shift Unitmentioning

confidence: 99%

“…Especially biomass steam gasification, employing the dual fluidized bed (DFB) technology is a proven process. Various products from the biomass, for example, electricity, heat, hydrogen, synthetic natural gas, FischerTropsch products, and alcohols (see [6,20,21,23]) can be produced.…”

Section: Introductionmentioning

confidence: 99%

Behavior of GCMS tar components in a water gas shift unit operated with tar-rich product gas from an industrial scale dual fluidized bed biomass steam gasification plant

Kraussler

Binder

Hofbauer

2016

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In this paper, the behavior of gas chromatography mass spectroscopy (GCMS) tar components in a three-stage water gas shift (WGS) unit is discussed. The GCMS tar measurements were carried out during the long-term operation (2250 h) of a WGS unit with tar-rich product gas from the commercial biomass steam gasification plant in Oberwart, Austria. In order to investigate the behavior of the GCMS tar components, four tar measurements were performed during the long-term operation of the WGS unit which employed a commercial Fe/Cr-based catalyst. The tar-rich product gas was extracted before reaching the scrubbing unit of the biomass steam gasification plant, therefore, the extracted gas contained a high amount of tar. In order to investigate the behavior of the GCMS tar in the WGS unit, the GCMS tar concentrations were determined at the inlet and the outlet of the WGS unit. The samples were taken during full load operation and during partial load operation of the WGS unit, respectively, the biomass steam gasification plant. In addition to the increase of the volumetric hydrogen content from about 40 % (d.b.) to 50 % (d.b.), the amount of GCMS tar was reduced (up to 38 %) as the gas passed through the WGS unit. No catalyst deactivation was observed. Furthermore, the efficiency of the hydrogen increase or the GCMS tar reduction did not depend on whether the operation of the WGS unit, respectively, the gasification plant was at partial load or full load.