The impact of bed material cycle rate on in-situ CO2 removal for sorption enhanced reforming of different fuel types

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In many processes proposed for biorefineries, recycling procedures, and industrial or agricultural production processes, residue is generated which could be further transformed by thermochemical conversion via gasification. The technology of dual fluidized bed steam gasification is capable of producing a valuable product gas out of such residue. The generated nitrogen-free product gas can be used for heat and power production and is suitable for separating gases (e.g. hydrogen). However, if the product gas is cleaned, its use as syngas is more beneficial for manufacturing renewable chemical substances, like synthetic natural gas, methanol, Fischer-Tropsch liquids, or mixed alcohols. This paper presents the results of experimental research from gasification test runs of different biogenic fuels, carried out with an advanced 100 kW pilot plant over the last 5 years at TU Wien. The focus is to provide an overview of measured results validated by mass and energy balances and to present key calculated performance indicating key figures of the test runs. In this way, the influence of various operational parameters and the composition of the product gas are evaluated. The presented results form the basis for the proper design of suitable gas-cleaning equipment. Subsequently, the clean syngas is available for several synthesis applications in future biorefineries.

Section: Influence Of Cycle Rate On Sorption-enhanced Gasificationmentioning

confidence: 99%

Section: Influence Of Cycle Rate On Sorption-enhanced Gasificationmentioning

confidence: 99%

Syngas for biorefineries from thermochemical gasification of lignocellulosic fuels and residues—5 years’ experience with an advanced dual fluidized bed gasifier design

Schmid

Benedikt

Fuchs

et al. 2019

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“…It was filled into the pilot plant as calcium carbonate (CaCO 3 ). There, CaCO 3 was converted to the catalytically active form calcium oxide (CaO) due to the high temperatures in the reactor system [39]. CaO showed high catalytic activity, which was advantageous for the ongoing gasification reaction.…”

Section: Investigated Materialsmentioning

confidence: 99%

CO2 gasification of biogenic fuels in a dual fluidized bed reactor system

Mauerhofer

Müller

Benedikt

et al. 2019

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A 100 kW th 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 CO 2 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 CO 2 contents. Additionally, the presence of alkali metals in the biomass ash favoured the production of CO. The addition of limestone enhanced the H 2 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 CO 2 as gasification agent. Keywords CO 2 gasification. Biomass. Biogenic residue. 100 kW th pilot plant. CO 2 conversion. Hydrogen balance

“…For many synthesis processes like methanation, a certain H 2 to CO ratio is necessary. Typically, the product gas composition of the SER process is highly dependent on gasification temperature and bed material cycle rate [12,13]. Via SER, an in situ adjustment of the H 2 to CO ratio between 2 and 9 is possible, which is clearly superior over the conventional gasification with olivine as the bed material, where only a H 2 to CO ratio up to 2 can be adjusted.…”

Section: Sorption Enhanced Reformingmentioning

confidence: 99%

“…It has already been shown that the SER process leads to a product gas with increased reduction potential [9,10], and further investigations were recommended to provide customized operation conditions of the process [9]. Theoretical thermodynamic investigations regarding the bed material renewable rate and bed material cycle rate have been presented in [11], and experimental considerations regarding the impact of bed material cycle rate and its influence on carbon balance have been published in [12]. Also, the description of the product gas composition in dependence of gasification temperature is well known [13].…”

Section: Introductionmentioning

confidence: 99%

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

Fuchs

Schmid

Müller

et al. 2019

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Especially 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 Bcarbonation dominated sorption enhanced reforming^and Bwater-gas shift dominated sorption enhanced reforming.T he 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).