scholarly journals Parametric Study on the Adjustability of the Syngas Composition by Sorption-Enhanced Gasification in a Dual-Fluidized Bed Pilot Plant

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 399
Author(s):  
Selina Hafner ◽  
Max Schmid ◽  
Günter Scheffknecht
Keyword(s):  
Fluidized Bed ◽  
Ghg Emissions ◽  
Space Velocity ◽  
Synthesis Process ◽  
Wood Pellets ◽  
High Hydrogen ◽  
Syngas Production ◽  
Dual Fluidized Bed ◽  
Bed Material ◽  
Gasification Temperature

Finding a way for mitigating climate change is one of the main challenges of our generation. Sorption-enhanced gasification (SEG) is a process by which syngas as an important intermediate for the synthesis of e.g., dimethyl ether (DME), bio-synthetic natural gas (SNG) and Fischer–Tropsch (FT) products or hydrogen can be produced by using biomass as feedstock. It can, therefore, contribute to a replacement for fossil fuels to reduce greenhouse gas (GHG) emissions. SEG is an indirect gasification process that is operated in a dual-fluidized bed (DFB) reactor. By the use of a CO2-active sorbent as bed material, CO2 that is produced during gasification is directly captured. The resulting enhancement of the water–gas shift reaction enables the production of a syngas with high hydrogen content and adjustable H2/CO/CO2-ratio. Tests were conducted in a 200 kW DFB pilot-scale facility under industrially relevant conditions to analyze the influence of gasification temperature, steam to carbon (S/C) ratio and weight hourly space velocity (WHSV) on the syngas production, using wood pellets as feedstock and limestone as bed material. Results revealed a strong dependency of the syngas composition on the gasification temperature in terms of permanent gases, light hydrocarbons and tars. Also, S/C ratio and WHSV are parameters that can contribute to adjusting the syngas properties in such a way that it is optimized for a specific downstream synthesis process.

scholarly journals A Detailed One-Dimensional Hydrodynamic and Kinetic Model for Sorption Enhanced Gasification

2020 ◽  
Vol 10 (17) ◽  
pp. 6136
Author(s):  
Marcel Beirow ◽  
Ashak Mahmud Parvez ◽  
Max Schmid ◽  
Günter Scheffknecht
Keyword(s):  
Fluidized Bed ◽  
Co2 Capture ◽  
Feeding Rate ◽  
Capture Rate ◽  
Reactor Performance ◽  
Operational Strategies ◽  
Syngas Production ◽  
Bubbling Fluidized Bed ◽  
Dual Fluidized Bed ◽  
Gasification Temperature

Increased installation of renewable electricity generators requires different technologies to compensate for the associated fast and high load gradients. In this work, sorption enhanced gasification (SEG) in a dual fluidized bed gasification system is considered as a promising and flexible technology for the tailored syngas production for use in chemical manufacturing or electricity generation. To study different operational strategies, as defined by gasification temperature or fuel input, a simulation model is developed. This model considers the hydrodynamics in a bubbling fluidized bed gasifier and the kinetics of gasification reactions and CO2 capture. The CO2 capture rate is defined by the number of carbonation/calcination cycles and the make-up of fresh limestone. A parametric study of the make-up flow rate (0.2, 6.6, and 15 kg/h) reveals its strong influence on the syngas composition, especially at low gasification temperatures (600–650 °C). Our results show good agreement with the experimental data of a 200 kW pilot plant, as demonstrated by deviations of syngas composition (5–34%), lower heating value (LHV) (5–7%), and M module (23–32%). Studying the fuel feeding rate (22–40 kg/h), an operational range with a good mixing of solids in the fluidized bed is identified. The achieved results are summarized in a reactor performance diagram, which gives the syngas power depending on the gasification temperature and the fuel feeding rate.

In-Situ CO2-Absorption in a Dual Fluidized Bed Biomass Steam Gasifier to Produce a Hydrogen Rich Syngas

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Christoph Pfeifer ◽  
Bernhard Puchner ◽  
Hermann Hofbauer
Keyword(s):  
Fluidized Bed ◽  
Renewable Energy Sources ◽  
Steam Gasification ◽  
Co2 Absorption ◽  
Producer Gas ◽  
High Hydrogen ◽  
Selective Transport ◽  
Operation Conditions ◽  
Dual Fluidized Bed ◽  
Bed Material

Within the last years renewable energy sources came more and more into the public focus. Steam gasification of solid biomass yields high quality producer gases that can be used for efficient combined heat and power production (CHP) and as a renewable resource for chemical syntheses. The dual fluidized bed steam gasification technology provides the necessary heat for steam gasification by circulating hot bed material that is heated in a second fluidized bed reactor by combustion of residual biomass char. The hydrogen content in producer gas of such gasifiers is about 40vol% (dry basis). Addition of carbonates to the bed material and adequate adjustment of operation conditions in the reactors allow selective transport of CO2 from gasification to combustion zone (Absorption Enhanced Reforming – AER concept). An 8MW (fuel power) CHP plant successfully demonstrates gasification in Guessing, Austria since 2002. A process development unit (100 kW fuel power) has been recently operated to investigate the potential of the selective CO2 transport achieving a H2 content of up to 75vol% (dry basis) in the producer gas. No significant increase in tar formation occurs despite the low gasification temperatures (600-700°C). It can be shown, that the selective transport of CO2 yields high hydrogen contents in the producer gas and the possibility of operating at lower temperatures increases the efficiency of energy conversion.

Experimental Parameter Study on Synthesis Gas Production by Steam-Oxygen Fluidized Bed Gasification of Sewage Sludge

2021 ◽  
Vol 11 (2) ◽  
pp. 579
Author(s):  
Max Schmid ◽  
Selina Hafner ◽  
Günter Scheffknecht
Keyword(s):  
Sewage Sludge ◽  
Fluidized Bed ◽  
Experimental Parameter ◽  
Space Velocity ◽  
Phosphate Fertilizer ◽  
Gas Production ◽  
Raw Material ◽  
Parameter Study ◽  
Syngas Production ◽  
Fuels And Chemicals

The conversion of biogenic residues to fuels and chemicals via gasification and synthesis processes is a promising pathway to replace fossil carbon. In this study, the focus is set on sewage sludge gasification for syngas production. Experiments were carried out in a 20 kW fuel input bubbling fluidized bed facility with steam and oxygen as gasification agent. In-situ produced sewage sludge ash was used as bed material. The sensitivity of the key operation parameters gasifier temperature, oxygen ratio, steam to carbon ratio, and the space velocity on the syngas composition (H2, CO, CO2, CH4, CxHy, H2S, COS, NH3, and tars) was determined. The results show that the produced syngas has high H2 and CO concentrations of up to 0.37 m3 m−3 and 0.18 m3 m−3, respectively, and is thus suitable for synthesis of fuels and chemicals. By adjusting the steam to carbon ratio, the syngas’ H2 to CO ratio can be purposely tailored by the water gas shift reaction for various synthesis products, e.g., synthetic natural gas (H2/CO = 3) or Fischer–Tropsch products (H2/CO = 2). Also, the composition and yields of fly ash and bed ash are presented. Through the gasification process, the cadmium and mercury contents of the bed ash were drastically reduced. The ash is suitable as secondary raw material for phosphorous or phosphate fertilizer production. Overall, a broad database was generated that can be used for process simulation and process design.

scholarly journals Tar abatement for clean syngas production during biomass gasification in a dual fluidized bed

2016 ◽  
Vol 152 ◽  
pp. 116-123 ◽  
Author(s):  
L.F. de Diego ◽  
F. García-Labiano ◽  
P. Gayán ◽  
A. Abad ◽  
T. Mendiara ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Biomass Gasification ◽  
Syngas Production ◽  
Dual Fluidized Bed

scholarly journals Parametric experimental tests of steam gasification of pine wood in a fluidized bed reactor

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
L. Vecchione ◽  
M. Moneti ◽  
S. Cocchi ◽  
M. Villarini ◽  
M. Sisinni ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Renewable Energy Sources ◽  
Ghg Emissions ◽  
Experimental Tests ◽  
Steam Gasification ◽  
High Hydrogen ◽  
Bench Scale ◽  
Residual Biomass ◽  
Industrial Sectors ◽  
Pine Trees

Among Renewable Energy Sources (RES), biomass represent one of the most common and suitable solution in order to contribute to the global energy supply and to reduce greenhouse gases (GHG) emissions. The disposal of some residual biomass, as pruning from pine trees, represent a problem for agricultural and agro-industrial sectors. But if the residual biomass are used for energy production can become a resource. The most suitable energy conversion technology for the above-mentioned biomass is gasification process because the high C/N ratio and the low moisture content, obtained from the analysis. In this work a small-pilot bubbling-bed gasification plant has been designed, constructed and used in order to obtain, from the pine trees pruning, a syngas with low tar and char contents and high hydrogen content. The activities showed here are part of the activities carried out in the European 7FP UNIfHY project. In particular the aim of this work is to develop experimental test on a bench scale steam blown fluidized bed biomass gasifier. These tests will be utilized in future works for the simulations of a pilot scale steam fluidized bed gasifier (100 kWth) fed with different biomass feedstock. The results of the tests include produced gas and tar composition as well gas, tar and char yield. Tests on a bench scale reactor (8 cm I.D.) were carried out varying steam to biomass ratio from 0.5, 0.7 and 1 to 830°C.

An Experiment on Solid Circulation Characteristics of a Dual Circulating fluidized Bed Based on Biomaterial Properties and Mechanics Properties

2012 ◽  
Vol 600 ◽  
pp. 261-264
Author(s):  
Teng Ge Mi ◽  
Ying Zhao ◽  
Chang Qing Dong ◽  
Wei Liang Cheng
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Circulation Rate ◽  
Gas Velocity ◽  
Solid Circulation Rate ◽  
Dual Fluidized Bed ◽  
Bed Material ◽  
Circulation Characteristics

In this paper, a dual fluidized bed has been established. The effect of bed material build-up height and gas velocity on the solid circulation rate of CFB (circulating fluidized bed) and BFB (bubble fluidized bed) has been studied. The results show that the solid circulation rate is increased with the increasing of gas velocity Uc and the bed material build-up height. Bed material build-up height of BFB and CFB is changed with the changing of gas velocity Uc. The bed material heights of CFB and BFB have been also investigated in this experiment.

High H2/CO Ratio Syngas Production from Chemical Looping Gasification of Sawdust in a Dual Fluidized Bed Gasifier

2016 ◽  
Vol 30 (3) ◽  
pp. 1764-1770 ◽  
Author(s):  
Jimin Zeng ◽  
Rui Xiao ◽  
Dewang Zeng ◽  
Yang Zhao ◽  
Huiyan Zhang ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Chemical Looping ◽  
Syngas Production ◽  
Dual Fluidized Bed ◽  
Fluidized Bed Gasifier

scholarly journals Mixtures of Silica Sand and Calcite as Bed Material for Dual Fluidized Bed Steam Gasification

2017 ◽  
Author(s):  
Anna Magdalena Mauerhofer ◽  
Florian Benedik ◽  
Johannes Christian Schmid ◽  
Hermann Hofbauer
Keyword(s):  
Fluidized Bed ◽  
Steam Gasification ◽  
Silica Sand ◽  
Dual Fluidized Bed ◽  
Bed Material
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