Process Performance of a Biotrickling Filter Using a Flow-Directional-Switching Method

2013 ◽  
Vol 41 (6) ◽  
pp. 522-527 ◽  
Author(s):  
Liping Wang ◽  
Shilong He ◽  
Jiangcen Xu ◽  
Jie Li ◽  
Zhen Mao
Keyword(s):  
Biotrickling Filter ◽  
Process Performance ◽  
Switching Method

scholarly journals Simultaneous Removal of Hexane and Ethanol from Air in a Biotrickling Filter—Process Performance and Monitoring Using Electronic Nose

2020 ◽  
Vol 12 (1) ◽  
pp. 387
Author(s):  
Piotr Rybarczyk ◽  
Bartosz Szulczyński ◽  
Jacek Gębicki
Keyword(s):  
Electronic Nose ◽  
Synergistic Effects ◽  
Biotrickling Filter ◽  
Simultaneous Removal ◽  
Process Performance ◽  
Feed Composition ◽  
Hydrophobic Compounds ◽  
Start Up ◽  
Filter Process ◽  
Air Streams

Biofiltration is a well-accepted method for the removal of malodorous compounds from air streams. Interestingly, the mechanisms underlying this process are not fully understood. The aim of this paper was to investigate the simultaneous removal of hydrophobic hexane with hydrophilic ethanol, resulting in the enhanced removal of hexane in the presence of ethanol. Investigations were performed in a peat-perlite packed biotrickling filter and the process performance was monitored using both gas chromatography and electronic nose techniques. The results indicate that the length as well as the efficiency of biofiltration during the start-up period depend on the feed composition, with higher efficiency obtained when hexane and ethanol were fed together from the process initiation. The experiments in the steady-state period present the biofilter performance when different ratios of hydrophilic to hydrophobic compounds were fed to the biofilter. The obtained results show the synergistic effects of the addition of a hydrophilic compound on the removal efficiency of hydrophobic hexane. The influence of the ratio of hydrophilic to hydrophobic compounds is discussed in terms of enhancing the mass transfer phenomena for hydrophobic volatile organic compounds.

scholarly journals Model-Based Analysis of Feedback Control Strategies in Aerobic Biotrickling Filters for Biogas Desulfurization

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 208
Author(s):  
Luis Rafael López ◽  
Mabel Mora ◽  
Caroline Van der Heyden ◽  
Juan Antonio Baeza ◽  
Eveline Volcke ◽  
...  
Keyword(s):  
Closed Loop ◽  
Control Strategies ◽  
Biotrickling Filter ◽  
Process Performance ◽  
Control Loops ◽  
Biotrickling Filters ◽  
Model Based ◽  
Outlet Concentration ◽  
The Impact ◽  
Model Based Analysis

Biotrickling filters are one of the most widely used biological technologies to perform biogas desulfurization. Their industrial application has been hampered due to the difficulty to achieve a robust and reliable operation of this bioreactor. Specifically, biotrickling filters process performance is affected mostly by fluctuations in the hydrogen sulfide (H2S) loading rate due to changes in the gas inlet concentration or in the volumetric gas flowrate. The process can be controlled by means of the regulation of the air flowrate (AFR) to control the oxygen (O2) gas outlet concentration ([O2]out) and the trickling liquid velocity (TLV) to control the H2S gas outlet concentration ([H2S]out). In this work, efforts were placed towards the understanding and development of control strategies in biological H2S removal in a biotrickling filter under aerobic conditions. Classical proportional and proportional-integral feedback controllers were applied in a model of an aerobic biotrickling filter for biogas desulfurization. Two different control loops were studied: (i) AFR Closed-Loop based on AFR regulation to control the [O2]out, and (ii) TLV Closed-Loop based on TLV regulation to control the [H2S]out. AFR regulation span was limited to values so that corresponds to biogas dilution factors that would give a biogas mixture with a minimum methane content in air, far from those values required to obtain an explosive mixture. A minimum TLV of 5.9 m h−1 was applied to provide the nutrients and moisture to the packed bed and a maximum TLV of 28.3 m h−1 was set to prevent biotrickling filter (BTF) flooding. Control loops were evaluated with a stepwise increase from 2000 ppmv until 6000 ppmv and with changes in the biogas flowrate using stepwise increments from 61.5 L h−1 (EBRT = 118 s) to 184.5 L h−1 (EBRT = 48.4 s). Controller parameters were determined based on time-integral criteria and simple criteria such as stability and oscillatory controller response. Before implementing the control strategies, two different mass transfer correlations were evaluated to study the effect of the manipulable variables. Open-loop behavior was also studied to determine the impact of control strategies on process performance variables such as removal efficiency, sulfate and sulfur selectivity, and oxygen consumption. AFR regulation efficiently controlled [O2]out; however, the impact on process performance parameters was not as great as when TLV was regulated to control [H2S]out. This model-based analysis provided valuable information about the controllability limits of each strategy and the impact that each strategy can have on the process performance.

scholarly journals Effects of n-butanol presence, inlet loading, empty bed residence time and starvation periods on the performance of a biotrickling filter removing cyclohexane vapors from air

2019 ◽  
Vol 74 (3) ◽  
pp. 1039-1047 ◽  
Author(s):  
Piotr Rybarczyk ◽  
Bartosz Szulczyński ◽  
Milena Gospodarek ◽  
Jacek Gębicki
Keyword(s):  
Residence Time ◽  
Chemical Properties ◽  
Biotrickling Filter ◽  
Mixed System ◽  
Process Performance ◽  
Basic Process ◽  
Filter Performance ◽  
Air Stream ◽  
Filter Effects ◽  
Empty Bed Residence Time

Abstract This paper presents the results of investigations on the removal of cyclohexane vapors from air using a peat-perlite packed biotrickling filter. Effects of basic process parameters i.e. inlet loading and empty bed residence time as well as introduction of n-butanol to the treated air stream and starvation periods on the process performance were evaluated. The results show that the introduction of hydrophilic n-butanol results in an enhanced removal of hydrophobic cyclohexane comparing to the experiments where only cyclohexane was treated. Additionally, the biotrickling filter performance after the starvation events is regained to more extent for mixed system than for the single cyclohexane. A novel and interesting element of the paper is the application of an electronic nose for the process monitoring. Obtained results are discussed in the perspective of an influence of the presence of a compound with different affinity to aqueous phase on the removal efficiency of the compound with opposite chemical properties.

Study on the Performance of an Anoxic Biotrickling Filter for the Removal of Hydrogen Sulphide from Biogas

2008 ◽  
Vol 43 (2-3) ◽  
pp. 211-218 ◽  
Author(s):  
Gabriela Soreanu ◽  
Patricia Falletta ◽  
Michel Béland ◽  
Kara Edmonson ◽  
Peter Seto
Keyword(s):  
Hydrogen Sulphide ◽  
Volcanic Rocks ◽  
Elemental Sulphur ◽  
Biotrickling Filter ◽  
Process Performance ◽  
Loading Rates ◽  
Biotrickling Filters ◽  
In Series ◽  
Continuous Dynamic ◽  
Sulphur Recovery

Abstract The paper presents aspects related to the performance of an anoxic biotrickling filter designed for hydrogen sulphide (H2S) removal from biogas. In this process, nitrate was supplied through a nutrient solution as an electron acceptor for anoxic growth of H2S-oxydizing microorganisms. The biotrickling filter's packing media consisted of a layer of plastic fibres over volcanic rocks in a ratio 0.78:1 by volume. The total volume of packing media was 0.014 m3. Several H2S loading rates (IL) were tested under continuous dynamic conditions, ranging between 20 and 550 g of H2S feed/(m3bed·day). Maximum process performance (>95%) was observed for IL ranging up to approximately 300 g of H2S feed/(m3bed·day). The degradation of hydrogen sulphide occurred with the formation of both sulphate and elemental sulphur, their formation ratio being dependent on H2S loading rate. Elemental sulphur was found to be the dominant degradation product, particularly at IL > 96.18 g of H2S feed/(m3bed·day). The use of two biotrickling filters in series was also tested, and a significant improvement in process performance was observed. This technology allows simple operation with low maintenance and has the potential for sulphur recovery.

High-Speed Switching Method of MOSFETs Using Switching Assist Auxiliary Circuit

2013 ◽  
Vol 133 (12) ◽  
pp. 1186-1192
Author(s):  
Toshihiko Noguchi ◽  
Tomohiro Mizuno ◽  
Munehiro Murata
Keyword(s):  
High Speed ◽  
Switching Method ◽  
High Speed Switching ◽  
Auxiliary Circuit
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