Abstract
The present work deals with a process for the methanation of the synthesis-gas from allothermal fluidized bed gasification. In the proposed process, the tar and sulfur contaminated syngas is used in a fixed-bed methanation reactor without further gas treatment. Commercial nickel catalysts are applied, which offer the opportunity to bring the gas to stoichiometry, in order to remove sulfur compounds by adsorption and to reform the synthesis-gas tar-content directly in the methanation reactor. An increased catalyst consumption turns out to be disadvantageous for the process. For process development in the course of this work, a biomass-fueled allothermic fluidized bed gasifier (Q{sub BR}=5kW) as well as a polytropic temperature-controlled methanation-reactor was constructed, built up and put into operation. It is possible to operate the system fully remote-controlled, which enables long-term tests without staff on site. Within the step of modelling with the software package ASPEN Plus in advance of experiments, parametric studies of both, the gasifier as well as of the process of methanation, were performed. As a major result, it can be shown that due to the use of nickel as methanation-catalyst-material, the educt gas-conversion is independent of the synthesis-gas's H{sub 2}/CO-ratio. Gasification tests were made to investigate the allothermic
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Citation Formats
Kienberger, Thomas.
Methanization of biogenic synthetic gases with respect to direct reaction of higher hydrocarbons; Methanisierung biogener Synthesegase mit Hinblick auf die direkte Umsetzung von hoeheren Kohlenwasserstoffen.
Germany: N. p.,
2010.
Web.
Kienberger, Thomas.
Methanization of biogenic synthetic gases with respect to direct reaction of higher hydrocarbons; Methanisierung biogener Synthesegase mit Hinblick auf die direkte Umsetzung von hoeheren Kohlenwasserstoffen.
Germany.
Kienberger, Thomas.
2010.
"Methanization of biogenic synthetic gases with respect to direct reaction of higher hydrocarbons; Methanisierung biogener Synthesegase mit Hinblick auf die direkte Umsetzung von hoeheren Kohlenwasserstoffen."
Germany.
@misc{etde_21397329,
title = {Methanization of biogenic synthetic gases with respect to direct reaction of higher hydrocarbons; Methanisierung biogener Synthesegase mit Hinblick auf die direkte Umsetzung von hoeheren Kohlenwasserstoffen}
author = {Kienberger, Thomas}
abstractNote = {The present work deals with a process for the methanation of the synthesis-gas from allothermal fluidized bed gasification. In the proposed process, the tar and sulfur contaminated syngas is used in a fixed-bed methanation reactor without further gas treatment. Commercial nickel catalysts are applied, which offer the opportunity to bring the gas to stoichiometry, in order to remove sulfur compounds by adsorption and to reform the synthesis-gas tar-content directly in the methanation reactor. An increased catalyst consumption turns out to be disadvantageous for the process. For process development in the course of this work, a biomass-fueled allothermic fluidized bed gasifier (Q{sub BR}=5kW) as well as a polytropic temperature-controlled methanation-reactor was constructed, built up and put into operation. It is possible to operate the system fully remote-controlled, which enables long-term tests without staff on site. Within the step of modelling with the software package ASPEN Plus in advance of experiments, parametric studies of both, the gasifier as well as of the process of methanation, were performed. As a major result, it can be shown that due to the use of nickel as methanation-catalyst-material, the educt gas-conversion is independent of the synthesis-gas's H{sub 2}/CO-ratio. Gasification tests were made to investigate the allothermic fluidized bed gasifier, in order to find an optimum point of operation for the downstream methane-synthesis. In the found point of operation, due to a sufficient water-content in the synthesis gas, from the thermodynamic perspective, carbon deposits on the methanation-catalyst can be avoided. The synthesis gas has a gravimetric tar-load of 10,4 g/Nm{sup 3}, furthermore hydrogen sulfide (H{sub 2}S) with a concentration of around 8 ppm{sub v} was measured as the representative sulfur component. It this gas is led to the methanation-reactor, in contrast to attempts with a clean synthesis-gas, the equilibrium-composition cannot be achieved. To reach the equilibrium-composition, a required space velocity GHSV of 1000 h{sup -1} was determined. The stoichiometric excess steam ratio {sigma} strongly determines the catalysts lifetime. When an excess steam ratio {sigma} of 6 is applied, the catalyst deactivation by the extent of carbon is reduced, so that an influence of the sulfur compounds of the synthesis gas is already detected. The specific catalyst consumption is thereby 2.75 g/Nm{sup 3}Syn{sub Gas}. In the proposed methanation-process, the synthesis gas's tar-load is converted to more than over 97%. The temperature peaks measured in the polytropic reactor show that reforming of the tars likely appears. (orig.)}
place = {Germany}
year = {2010}
month = {Jul}
}
title = {Methanization of biogenic synthetic gases with respect to direct reaction of higher hydrocarbons; Methanisierung biogener Synthesegase mit Hinblick auf die direkte Umsetzung von hoeheren Kohlenwasserstoffen}
author = {Kienberger, Thomas}
abstractNote = {The present work deals with a process for the methanation of the synthesis-gas from allothermal fluidized bed gasification. In the proposed process, the tar and sulfur contaminated syngas is used in a fixed-bed methanation reactor without further gas treatment. Commercial nickel catalysts are applied, which offer the opportunity to bring the gas to stoichiometry, in order to remove sulfur compounds by adsorption and to reform the synthesis-gas tar-content directly in the methanation reactor. An increased catalyst consumption turns out to be disadvantageous for the process. For process development in the course of this work, a biomass-fueled allothermic fluidized bed gasifier (Q{sub BR}=5kW) as well as a polytropic temperature-controlled methanation-reactor was constructed, built up and put into operation. It is possible to operate the system fully remote-controlled, which enables long-term tests without staff on site. Within the step of modelling with the software package ASPEN Plus in advance of experiments, parametric studies of both, the gasifier as well as of the process of methanation, were performed. As a major result, it can be shown that due to the use of nickel as methanation-catalyst-material, the educt gas-conversion is independent of the synthesis-gas's H{sub 2}/CO-ratio. Gasification tests were made to investigate the allothermic fluidized bed gasifier, in order to find an optimum point of operation for the downstream methane-synthesis. In the found point of operation, due to a sufficient water-content in the synthesis gas, from the thermodynamic perspective, carbon deposits on the methanation-catalyst can be avoided. The synthesis gas has a gravimetric tar-load of 10,4 g/Nm{sup 3}, furthermore hydrogen sulfide (H{sub 2}S) with a concentration of around 8 ppm{sub v} was measured as the representative sulfur component. It this gas is led to the methanation-reactor, in contrast to attempts with a clean synthesis-gas, the equilibrium-composition cannot be achieved. To reach the equilibrium-composition, a required space velocity GHSV of 1000 h{sup -1} was determined. The stoichiometric excess steam ratio {sigma} strongly determines the catalysts lifetime. When an excess steam ratio {sigma} of 6 is applied, the catalyst deactivation by the extent of carbon is reduced, so that an influence of the sulfur compounds of the synthesis gas is already detected. The specific catalyst consumption is thereby 2.75 g/Nm{sup 3}Syn{sub Gas}. In the proposed methanation-process, the synthesis gas's tar-load is converted to more than over 97%. The temperature peaks measured in the polytropic reactor show that reforming of the tars likely appears. (orig.)}
place = {Germany}
year = {2010}
month = {Jul}
}