scholarly journals Development of Biomass Gasification Technology with Fluidized-Bed Reactors for Enhancing Hydrogen Generation: Part I, Hydrodynamic Characterization of Dual Fluidized-Bed Gasifiers

2019 ◽  
Vol 10 (1) ◽  
pp. 2 ◽  
Author(s):  
Yau-Pin Chyou ◽  
Der-Ming Chang ◽  
Po-Chuang Chen ◽  
Hsiu-Yun Chien ◽  
Keng-Tung Wu ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Hydrogen Generation ◽  
Clean Energy ◽  
Chemical Conversion ◽  
Biomass Gasification ◽  
Experimental Results ◽  
Hydrodynamic Characteristics ◽  
Fluidized Bed Reactors ◽  
Cold Model ◽  
Gasification Technology

Various means for enhancing hydrogen content in the syngas from gasification of solid biomass in fluidized-bed reactors were investigated in this study. Steam or oxygen-rich gas can be supplied as gasification medium, to improve the syngas characteristics. Alternatively, a so-called “indirect gasification technology” realizes the thermo-chemical conversion processes in dual reactors, respectively, for combustion and gasification, where gaseous streams in between are separated while solid materials are circulated through. Hence, with air as oxidant for combustion this system features the advantage of producing nearly nitrogen-free syngas. Baseline experiments were firstly carried out to identify performance features; then, parametric studies were conducted and positive trends for enhancing hydrogen generation via biomass gasification were revealed. Moreover, hydrodynamic characteristics in dual reactors were comprehensively envisaged in the cold-flow models to facilitate subsequent investigation into thermo-chemical processes. The experimental results indicated that the circulation mass of the bed material driven by the operating air exceeded the design value, which gave a comfortable safety factor of the engineering design. In addition, the average pressure distribution measured by the cyclic operation of the system was similar to that of the published literature. Based on the experimental results of the cold model, the suggestions of the operating tests in the hot model were addressed. Further efforts will be pursued to establish databases for clean energy and carbon abatement technologies.

scholarly journals Study on the enhancement of hydrogen generation via biomass gasification in fluidizedbed reactors

2019 ◽  
Vol 83 ◽  
pp. 01001
Author(s):  
Yau-Pin Chyou ◽  
Po-Chuang Chen ◽  
Der-Ming Chang ◽  
Keng-Tung Wu ◽  
Rei-Yu Chein
Keyword(s):  
Fluidized Bed ◽  
Hydrogen Generation ◽  
Preliminary Test ◽  
Clean Energy ◽  
Biomass Gasification ◽  
Fluidized Bed Reactors ◽  
Carbon Abatement ◽  
Bubbling Fluidized Bed ◽  
Fluidized Bed Gasifier ◽  
Solid Biomass

In this study, solid biomass is gasified in fluidized-bed reactors, to investigate the effect of various means on syngas composition, especially for enhancing hydrogen content in the production gas. Conventionally, air is supplied to the reactor as gasification medium, which inevitably results in a high nitrogen content in the syngas. Alternatively, steam or oxygen-rich gas can be supplied to improve the syngas characteristics. On the other hand, a so-called “indirect gasification technology” realizes the whole conversion processes in dual reactors, for combustion and gasification, respectively; moreover, solid materials are circulated through two reactors, while gaseous streams in between are separated from each other. Hence, this system features the advantage of producing near nitrogen-free syngas in the gasifier, with air as oxidant in the combustor. Baseline experiments with various operating parameters, including air equivalence ratio (ER) and temperature, were firstly performed in a 30 kWth bubbling fluidized-bed gasifier; then, trial tests were conducted with the aforementioned operational and constructional factors. The preliminary test data show positive trends for the enhancement of hydrogen generation via biomass gasification. Further efforts will be pursued to establish a data base, which would be beneficial to extensive researches on clean energy and carbon abatement technologies.

scholarly journals Hydrogen Production by Fluidized Bed Reactors: A Quantitative Perspective Using the Supervised Machine Learning Approach

J ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 266-287
Author(s):  
Zheng Lian ◽  
Yixiao Wang ◽  
Xiyue Zhang ◽  
Abubakar Yusuf ◽  
Lord Famiyeh ◽  
...  
Keyword(s):  
Machine Learning ◽  
Hydrogen Production ◽  
Fluidized Bed ◽  
Biomass Gasification ◽  
Supervised Machine Learning ◽  
Fluidized Bed Reactors ◽  
Hydrogen Yield ◽  
Carbon Conversion ◽  
Operational Parameters ◽  
Operational Conditions

The current hydrogen generation technologies, especially biomass gasification using fluidized bed reactors (FBRs), were rigorously reviewed. There are involute operational parameters in a fluidized bed gasifier that determine the anticipated outcomes for hydrogen production purposes. However, limited reviews are present that link these parametric conditions with the corresponding performances based on experimental data collection. Using the constructed artificial neural networks (ANNs) as the supervised machine learning algorithm for data training, the operational parameters from 52 literature reports were utilized to perform both the qualitative and quantitative assessments of the performance, such as the hydrogen yield (HY), hydrogen content (HC) and carbon conversion efficiency (CCE). Seven types of operational parameters, including the steam-to-biomass ratio (SBR), equivalent ratio (ER), temperature, particle size of the feedstock, residence time, lower heating value (LHV) and carbon content (CC), were closely investigated. Six binary parameters have been identified to be statistically significant to the performance parameters (hydrogen yield (HY)), hydrogen content (HC) and carbon conversion efficiency (CCE)) by analysis of variance (ANOVA). The optimal operational conditions derived from the machine leaning were recommended according to the needs of the outcomes. This review may provide helpful insights for researchers to comprehensively consider the operational conditions in order to achieve high hydrogen production using fluidized bed reactors during biomass gasification.

Fluidized bed heat treatment of aluminum cast components

2004 ◽  
Vol 120 ◽  
pp. 555-562
Author(s):  
D. Apelian ◽  
S. K. Chaudhury
Keyword(s):  
Heat Treatment ◽  
Fluidized Bed ◽  
Processing Time ◽  
Reaction Times ◽  
Experimental Results ◽  
Fluidized Bed Reactors ◽  
The Past ◽  
Conventional Furnace ◽  
Time Required ◽  
Solutionizing Time

Heat Treatment and post casting treatments of cast components has always been an important step in the control of microstructure, and resultant properties. In the past, the solutionizing, quenching and ageing process steps may have “required” in total over 20 hours of processing time. With the advent of fluidized bed reactors (FB), processing time has been dramatically reduced. For example, instead of 8-10 hours solutionizing time in a conventional furnace, the time required in FB is less than an hour. Experiments with Al-Si-Mg alloy, (both modified with Sr, and unmodified) were performed, having different diffusion distances (different DAS), and for different reaction times and temperatures. Both the model and the experimental results are presented and discussed.

Design of Fluidized Bed Co-Gasifier of Coal and Wastes Fuels

2015 ◽  
Vol 776 ◽  
pp. 300-306
Author(s):  
I. Nyoman Suprapta Winaya ◽  
Rukmi Sari Hartati ◽  
I. Putu Lokantara ◽  
I. Gan Subawa ◽  
I. Made Agus Putrawan
Keyword(s):  
Fluidized Bed ◽  
Research Group ◽  
Calorific Value ◽  
Clean Energy ◽  
Gas Production ◽  
Data Input ◽  
Pilot Plant Scale ◽  
Using Data ◽  
Internal Experience ◽  
Gasification Technology

The solid waste produced from urban area is an urgent issue to be addressed. A fluidized bed (FB) gasification technology has been widely applied and proven effective to convert waste into clean energy and environmentally friendly. Co-gasification is a technique of mixing two or more fuels that aims to improve calorific value of the gas production. A FB gasifier reactor is designed using some previous experiments and available literature as well as from the internal experience of the research group. The gasification reactor pilot plant scale using data input of waste and biomass fuels has been fabricated with diameter of 0.7 m and a height of 1.5 m. The Tests have been performed showing that the FB gasifier is very feasible to be developed.

Co-Combustion of Biomass and Coal in Circulating Fluidized Bed: Modeling and Validation

2003 ◽  
Author(s):  
Juan Ada´nez ◽  
Luis F. de Diego ◽  
Pilar Gaya´n ◽  
Francisco Garci´a-Labiano ◽  
Andre´s Cabanillas ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Plug Flow ◽  
Weighted Average ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Experimental Results ◽  
Hydrodynamic Characteristics ◽  
Particle Model ◽  
Carbon Combustion

In this work carbon combustion efficiencies in circulating fluidized bed combustion (CFBC) when co-firing biomass and coal mixtures were studied. Experimental results were obtained from the combustion of two kind of coals with a forest residue (Pine bark) in a CBF pilot plant (0.3MWth) with 20-cm i.d. and 6.5-m height. The effect of operating conditions such as percentage of biomass in the feed, temperature, excess air, air velocity and percentage of secondary air on carbon combustion efficiency was studied. A mathematical model for the co-combustion of coal and biomass in a circulating fluidized bed boiler has been developed. The riser is divided in three zones with different hydrodynamic characteristics: bottom, splash and freeboard. The bottom bed has a constant voidage, determined by a modified two-phase theory. The solids are considered in perfect mixing and the gas in plug flow. The voidage in the splash region follows an exponential decay model. In the freeboard region, the solids and the gas are in plug flow, and a core-annulus structure is considered. Devolatilization of solid fuels is modeled with a particle reaction model which allows to determine the volatiles generation rate as a function of time and operating conditions. Kinetics of char combustion is modeled with the shrinking particle model with mixed control by chemical reaction and gas film diffusion, assuming that the ashes separate once formed. To consider that the char particles are a mixture of coal and biomass char particles, a weighted average combustion rate is defined taking into account the individual combustion rates. Population balances of char particles in the different regions were developed to calculate carbon concentrations. The developed model can predict the different gas concentrations along the riser, such as oxygen, SO2, CO, CH4, etc..., and the carbon combustion efficiency. The experimental results of carbon combustion efficiencies and gas emissions were compared with those predicted by the model and a good correlation was found for all the conditions used.

Hydrodynamic characteristics in a cold model of the dual fluidized bed with mixed particles

2019 ◽  
Vol 351 ◽  
pp. 291-304 ◽  
Author(s):  
Xin Yang ◽  
Zherui Ma ◽  
Zhanwei Liang ◽  
Hongwei Chen ◽  
JiXuan Wang
Keyword(s):  
Fluidized Bed ◽  
Hydrodynamic Characteristics ◽  
Cold Model ◽  
Dual Fluidized Bed

Detailed Modeling of Biomass Gasification in Dual Fluidized Bed Reactors under Aspen Plus

2012 ◽  
Vol 26 (6) ◽  
pp. 3840-3855 ◽  
Author(s):  
L. Abdelouahed ◽  
O. Authier ◽  
G. Mauviel ◽  
J. P. Corriou ◽  
G. Verdier ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Aspen Plus ◽  
Biomass Gasification ◽  
Fluidized Bed Reactors ◽  
Dual Fluidized Bed
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