A Comparison of Different Support Materials in Anaerobic Fluidized Bed Reactors for the Treatment of Vinasse

In Cuba, the alcohol distillation process from cane sugar molasses, produces a final waste (vinasse), with an enormous polluting potential and a high sulfate content. Applying the anaerobic technology, most of the biodegradable organic matter can turn into biogas, rich in methane but with concentrations of sulfide above 1%. The present work develops two experiences with anaerobic fluidized bed reactors (AFBR) using both Cuban raw material, activated carbon and natural zeolite, as support media, with the purpose of obtaining high organic matter removal rates and keeping sulfide and ammonium concentrations in the permissible ranges. The reactors were operated during 120 days, achieving an organic loading rate of 10 kg COD/m3 day, with COD removal above 70%, and a methane production of 2 L/d. The activated carbon and natural zeolite used support materials in anaerobic fluidized bed reactors, and showed good results of distillery waste removal.

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Novel Synthesis of Silicon/Carbon Nanotubes Microspheres as Anode Additives Through Chemical Vapor Deposition in Fluidized Bed Reactors

SSRN Electronic Journal ◽

10.2139/ssrn.3659826 ◽

2020 ◽

Author(s):

Hong Zhao ◽

Ning TU ◽

Weibin Zhang ◽

Min Zhang ◽

Jian Wang

Keyword(s):

Carbon Nanotubes ◽

Chemical Vapor Deposition ◽

Fluidized Bed ◽

Vapor Deposition ◽

Chemical Vapor ◽

Fluidized Bed Reactors ◽

Novel Synthesis ◽

Silicon Carbon

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Influence of Seeding Conditions on Initial Biofilm Development during the Startup of Anaerobic Fluidized Bed Reactors

Water Science & Technology ◽

10.2166/wst.1989.0219 ◽

1989 ◽

Vol 21 (4-5) ◽

pp. 157-165 ◽

Cited By ~ 2

Author(s):

F. Ehlinger ◽

J. M. Audic ◽

G. M. Faup

Keyword(s):

Fluidized Bed ◽

Future Development ◽

Protein Concentration ◽

Specific Activity ◽

Fluidized Bed Reactor ◽

Fluidized Bed Reactors ◽

Support Material ◽

Biofilm Development ◽

Initial Biofilm

The characterization of the biofilm of an anaerobic fluidized-bed reactor was completed under standard conditions. The distribution of the fixed protein concentration depended on the level in the reactor. The protein concentration reached 1520 µg.g−1 of support at the top of the reactor and only 1200 µg.g−1 at the bottom after 504 hours of operation but the specific activity of the biofilm was 33×10−4 µM acetate.h−1.mg−1 proteins at the bottom and only 26×10−4 µM.h−1.mg−1 at the top. The efficiency of a fluidized bed reactor and the composition of the biofilm changed with an increase of the pH from 7 to 8.5 during the seeding of the support material. Future development of the biofilm and the specific activity of the support were affected.

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Anaerobic/aerobic biodegradation of pentachlorophenol using GAC fluidized bed reactors: optimization of the empty bed contact time

Water Science & Technology ◽

10.2166/wst.1997.0581 ◽

1997 ◽

Vol 36 (6-7) ◽

pp. 107-115 ◽

Cited By ~ 4

Author(s):

Gregory J. Wilson ◽

Amid P. Khodadoust ◽

Makram T. Suidan ◽

Richard C. Brenner

Keyword(s):

Fluidized Bed ◽

Oxygen Demand ◽

Aerobic Biodegradation ◽

Fluidized Bed Reactors ◽

Reactor Performance ◽

Reactor Operation ◽

Significant Cost ◽

Second Stage ◽

Primary Substrate ◽

Chlorinated Phenolic Compounds

An integrated reactor system has been developed to remediate pentachlorophenol (PCP) containing wastes using sequential anaerobic and aerobic biodegradation. Anaerobically, PCP was degraded to predominately equimolar concentrations (>99%) of monochlorophenol (MCP) in two GAC fluidized bed reactors at Empty Bed Contact Times (EBCTs) ranging from 18.6 to 1.15 hours. However, at lower EBCTs, MCP concentrations decreased to less than 10% of the influent PCP concentration suggesting mineralization. The optimal EBCT was determined to be 2.3 hours based on PCP conversion to MCPs and stable reactor operation. Decreasing the EBCT fourfold did not inhibit degradation of PCP and its intermediates, thus allowing removal of PCP at much lower detention time and resulting in a significant cost advantage. Analytical grade PCP was fed via syringe pumps into two fluidized bed reactors at influent concentrations of 100 mg/l and 200 mg/l, respectively. Acting as the primary substrate, ethanol was also fed into the reactors at concentrations of 697 and 1388 mg/l. Effluent PCP and chlorinated phenolic compounds were analyzed weekly to evaluate reactor performance. Biodegradation pathways were also identified. 3-chlorophenol (CP) was the predominant MCP and varied simultaneously with 3,5-dichlorophenol (DCP) concentrations. Likewise, 4-CP concentrations varied simultaneously with 3,4-DCP concentrations. A second stage aerobic GAC fluidized bed reactor was added after the anaerobic reactor to completely mineralize the remaining MCP and phenols. Data show no presence of phenol and MCP in the effluent or on the GAC. Overall, the chemical oxygen demand (COD) fed to the system was reduced from 75 g/d in the influent to less than 1.5 g/d in the effluent.

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Aromatic Transformation in Fluidized Bed Reactors

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20081061 ◽

2008 ◽

Vol 73 (8-9) ◽

pp. 1061-1088

Author(s):

Sule Rabiu ◽

Sulaiman Al-Khattaf

Keyword(s):

Fluidized Bed ◽

The Other ◽

Fluidized Bed Reactors ◽

Y Zeolite ◽

Y Zeolites ◽

Toluene Disproportionation ◽

Xylene Isomerization ◽

Toluene Methylation ◽

Toluene Conversion ◽

Medium Acidity

In this work three important aromatic transformations, namely: toluene disproportionation, toluene methylation and m-xylene isomerization, were investigated in a riser simulator which closely mimics the operation of commercial fluidized bed reactors. The transformations were studied over a ZSM-5 based catalyst with medium acidity of 0.23 mmol/g and a series of Y zeolites of acidities between 0.55 and 0.03 mmol/g. For pure toluene feed, it was observed that conversion over the ZSM-5 based catalyst and the weakly acidic Y zeolite (USY-1) was very low. However, with the highly acidic Y zeolite (H-Y), significant toluene conversion was observed with paring reaction more prominent than disproportionation. On the other hand, when toluene was alkylated with methanol, higher toluene conversions were achieved over both the ZSM-5 based and the weakly acidic USY-1 catalysts as compared to when pure toluene feed was used. In addition, p-xylene/o-xylene (P/O) ratios higher than the equilibrium values were obtained in the reaction product over both catalysts. Finally, for m-xylene isomerization it was found that m-xylene conversion increased initially as the acidity of the catalyst increased up to 0.1 mmol/g beyond which any further increase in acidity resulted in a slight decrease in the m-xylene conversion.

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Optimal polymer grade transitions for fluidized bed reactors

Journal of Process Control ◽

10.1016/j.jprocont.2020.02.001 ◽

2020 ◽

Vol 88 ◽

pp. 86-100 ◽

Cited By ~ 1

Author(s):

Yajun Wang ◽

Lorenz T. Biegler ◽

George S. Ostace ◽

Rita A. Majewski

Keyword(s):

Fluidized Bed ◽

Fluidized Bed Reactors

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

J ◽

10.3390/j4030022 ◽

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.

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