scholarly journals Influences of the Pretreatments of Residual Biomass on Gasification Processes: Experimental Devolatilizations Study in a Fluidized Bed

2021 ◽  
Vol 11 (12) ◽  
pp. 5722
Author(s):  
Stefania Lucantonio ◽  
Andrea Di Giuliano ◽  
Katia Gallucci
Keyword(s):  
Fluidized Bed ◽  
Molar Ratio ◽  
Thermochemical Conversion ◽  
Chemical Looping ◽  
Carbon Conversion ◽  
European Research ◽  
Residual Biomass ◽  
General Improvement ◽  
Straight Lines ◽  
Integral Average

The European research project CLARA (chemical looping gasification for sustainable production of biofuels, G.A. 817841) investigated chemical looping gasification of wheat straw pellets. This work focuses on pretreatments for this residual biomass, i.e., torrefaction and torrefaction-washing. Devolatilizations of individual pellets were performed in a laboratory-scale fluidized bed made of sand, at 700, 800, and 900 °C, to quantify and analyze the syngas released from differently pretreated biomasses; experimental data were assessed by integral-average parameters: gas yield, H2/CO molar ratio, and carbon conversion. A new analysis of devolatilization data was performed, based on information from instantaneous peaks of released syngas, by simple regressions with straight lines. For all biomasses, the increase of devolatilization temperature between 700 and 900 °C enhanced the thermochemical conversion in terms of gas yield, carbon conversion, and H2/CO ratio in the syngas. Regarding pretreatments, the main evidence is the general improvement of syngas quality (i.e., composition) and quantity, compared to those of untreated pellets; only slighter differentiations were observed concerning different pretreatments, mainly thanks to peak quantities, which highlighted an improvement of the H2/CO molar ratio in correlation with increased torrefaction temperature from 250 to 270 °C. The proposed methods emerged as suitable straightforward tools to investigate the behavior of biomasses and the effects of process parameters and biomass nature.

Experimental Studies on H2-Rich Gas Production by Co-Gasification of Coal and Biomass in an Intermittent Fluidized Bed Reactor

2013 ◽  
Vol 724-725 ◽  
pp. 1127-1131 ◽  
Author(s):  
Li Qun Wang ◽  
Zhao Sheng Chen
Keyword(s):  
Fluidized Bed ◽  
Experimental Studies ◽  
Fluidized Bed Reactor ◽  
Gas Production ◽  
Molar Ratio ◽  
Carbon Conversion ◽  
Mass Ratio ◽  
Heating Value ◽  
Product Gas ◽  
Gasification Temperature

This paper illustrates the experimental results of co-gasification of biomass and coal in an intermittent fluidized bed reactor, aiming to investigate the effects of gasification temperature (T) and steam to biomass mass ratio (SBMR) on the composition, yield, low heating value (LHV) and carbon conversion efficiency of the product gas. The results show that H2-rich gas with a high LHV is generated, in the range of 12.22-18.67 MJ/Nm3, and the H2 content in the product gas is in the range of 28.7-51.4%. Increases in temperature lead to an increase in CO and H2 content. The H2/CO molar ratio in the product gas is close to 1 at temperature above 925 °C. With steam addition, the H2 content increases gradually, while the content of CO increases first and then decrease correspondingly. The molar ratio of H2/CO is close to 1 with the smallest supplied amount of steam addition (SBMR =0.4).

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.

scholarly journals Investigation of biomass alkali release in a dual circulating fluidized bed chemical looping combustion system

Fuel ◽  
2021 ◽  
Vol 297 ◽  
pp. 120743
Author(s):  
Ivan Gogolev ◽  
Toni Pikkarainen ◽  
Juho Kauppinen ◽  
Carl Linderholm ◽  
Britt-Marie Steenari ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Combustion System

scholarly journals Characteristic Study of Briquette Cyanobacteria as Fuel in Chemical Looping Combustion with Hematite as Oxygen Carrier

2021 ◽  
Vol 11 (10) ◽  
pp. 4388
Author(s):  
Haifeng Zhang ◽  
Laihong Shen ◽  
Huijun Ge ◽  
Hongcun Bai
Keyword(s):  
Large Scale ◽  
Oxygen Carrier ◽  
Compressive Load ◽  
Phosphorus Recovery ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Carbon Conversion ◽  
Nitrogen And Phosphorus ◽  
Liquid Products ◽  
Lower Temperature

Due to the more and more serious cyanobacteria bloom problem, it is particularly urgent to find a technology suitable for large-scale disposal and the efficient recovery of abundant nitrogen and phosphorus resources in cyanobacteria. The combination of chemical looping combustion (CLC) and biomass densification technology is thought to be a promising utilization selection. Based on the experimental results, the mechanical strength and energy density of briquette cyanobacteria are evidently increased with the compressive load; whereas, 10% is the optimal moisture content in the densification process. A higher heating rate in TGA would result in the damage of the internal structure of the briquette cyanobacteria, which are conducive to the carbon conversion efficiency. The presence of a hematite oxygen carrier would enhance the carbon conversion and catalyzed crack liquid products. CO2 yield is increased 25 percent and CH4 yield is decreased 50 percent at 900 °C in the CLC process. In addition, the lower temperature and reduction atmosphere in CLC would result in a lower NO emission concentration. The reactivity and porous property of hematite OC in CLC also increased during 10 redox cycle experiments. The CLC process accelerates the generation of CaH2P2O7 and CaHPO4 in cyanobacteria ash, which is more conducive to phosphorus recovery.

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