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

Abstract A 100 kWth dual fluidized bed steam gasification pilot plant has been developed at TU Wien to convert different types of biogenic fuels into a valuable product gas. In this paper, the conversion of different biogenic fuels in combination with the utilization of CO2 as alternative gasification agent was investigated in the mentioned pilot plant. For this purpose, five experimental campaigns were carried out aiming at the investigation of softwood as reference fuel, and rapeseed cake, bark and lignin as alternative fuels. Pure olivine as well as a mixture (90/10 wt%) of olivine and limestone were used as bed materials. The product gas compositions of the different biogenic fuels changed depending on the elemental composition of the biogenic fuels. Thus, a high amount of carbon in the fuel enhanced CO formation, whereas an increased content of oxygen led to higher CO2 contents. Additionally, the presence of alkali metals in the biomass ash favoured the production of CO. The addition of limestone enhanced the H2 and CO contents via the water gas shift reaction as well as steam and dry reforming reactions, but had no significant effect on tar contents. Overall, this paper presents the feasibility of the dual-fluidized bed gasification process of different biogenic fuels with CO2 as gasification agent.

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H2 rich product gas by steam gasification of biomass with in situ CO2 absorption in a dual fluidized bed system of 8 MW fuel input

Fuel Processing Technology ◽

10.1016/j.fuproc.2009.03.016 ◽

2009 ◽

Vol 90 (7-8) ◽

pp. 914-921 ◽

Cited By ~ 204

Author(s):

Stefan Koppatz ◽

Christoph Pfeifer ◽

Reinhard Rauch ◽

Hermann Hofbauer ◽

Tonja Marquard-Moellenstedt ◽

...

Keyword(s):

Fluidized Bed ◽

Steam Gasification ◽

Co2 Absorption ◽

Product Gas ◽

Dual Fluidized Bed

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The impact of gasification temperature on the process characteristics of sorption enhanced reforming of biomass

Biomass Conversion and Biorefinery ◽

10.1007/s13399-019-00439-9 ◽

2019 ◽

Vol 10 (4) ◽

pp. 925-936 ◽

Cited By ~ 5

Author(s):

J. Fuchs ◽

J. C. Schmid ◽

S. Müller ◽

A. M. Mauerhofer ◽

F. Benedikt ◽

...

Keyword(s):

Equilibrium Composition ◽

Water Gas Shift ◽

Thermochemical Conversion ◽

Published Data ◽

Product Gas ◽

Dual Fluidized Bed ◽

Shift Reaction ◽

The Impact ◽

Water Gas ◽

Gasification Temperature

AbstractEspecially carbon-intensive industries are interested in a decarbonization of their processes. A technology, which can contribute to a significant reduction of the carbon footprint, is the so-called sorption enhanced reforming process. The sorption enhanced reforming process uses a dual fluidized bed reactor system with limestone as a bed material for the thermochemical conversion of biomass into a valuable nitrogen-free product gas. This product gas can be used for further synthesis processes like methanation. The dependency of the product gas composition on the gasification temperature is already a well-known fact. Nevertheless, detailed investigations and models of the effect on elemental balances (especially carbon) of the process are missing in the literature and are presented in this work. Therefore, previously published data from different pilot plants is summarized and is discussed on a mass balance. Based on this information, investigations on the product gas equilibrium composition are presented and conclusions are drawn: it can be shown that the sorption enhanced reforming process can be divided into two sub-processes, namely “carbonation dominated sorption enhanced reforming” and “water-gas shift dominated sorption enhanced reforming.” The sub-process carbonation dominated SER is characterized by a high deviation from the water-gas shift equilibrium and a nearly constant CO content in the product gas over gasification temperature (< 700 °C). The sub-process water-gas shift dominated SER can be identified by a steep increase of the CO content in the product gas over temperature and nearly equilibrium state of the water-gas shift reaction (700–760 °C).

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