Comparison of Different Methods for Evaluating the Hydraulics of a Pilot-Scale Upflow Anaerobic Sludge Blanket Reactor

Montiel, Jhonny Pérez; Montero, Andrés Galindo; Ramírez-Muńoz, J.

doi:10.1007/s40710-019-00354-1

Cited by 7 publications

(8 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Figure 5b, when the container TST was far from heat emitting When the stabilization time is zero (Figure 4a), the average curve of the tests indicates that the flow in the reactor behaves more like a plug flow [26] due to the low dispersion of the tracer, resulting in a peak E(θ) ∼ = 1.1 at θ ∼ = 0.9. However, when the stabilization time is extended, the tracer has a much more intense dispersion, obtaining an RTD curve similar to the typical curve of a tank reactor with dead zones and channeling, which is expected in a UASB reactor [13]. Stabilization times of 1τ (Figure 4b) and 2τ (Figure 4c) generated peaks of E(θ) ∼ = 1.0 at θ ∼ = 0.7 and E(θ) ∼ = 1.1 at θ ∼ = 0.6, respectively.…”

Section: Temperaturementioning

confidence: 70%

“…Lithium chloride (LiCl) [13], calcium chloride (CaCl2) [14], and sodium chloride (NaCl) [15] are compounds that have been successfully used as tracers for the hydrodynamic characterizations of wastewater treatment facilities. Fluorescent tracers such as fluorescein, rhodamine WT, and Eosin Y have also been used since they can be detected at very low concentrations [16,17].…”

Section: Introductionmentioning

confidence: 99%

“…Despite its simplicity, this technique is time-consuming, and human experimental errors can be amplified due to scaling effects (i.e., the effects of viscosity, temperature, and salinity that play a more important role in a laboratory or small-scale reactor than in a full-scale reactor), negatively impacting the accuracy of the results. Despite the importance of test repetition to determine the variation of the RTD curves, repetition is not commonly performed [13,19,20], possibly due to the associated high costs and efforts required. This limitation could imply that the validations of mathematical models or even the design of full-scale reactors that commonly use the information of RTD curves from scaled models could have large deviations from the actual behavior of the reactor.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Development of an Automated Tracer Testing System for UASB Laboratory-Scale Reactors

Cisneros

Peláez-Samaniego

Pinos-Vélez

et al. 2021

Water

View full text Add to dashboard Cite

Residence time distribution (RTD) curves play an essential role in the hydraulic characterization of reactors. Current approaches for obtaining RTD curves in laboratory-scale reactors are time-consuming and subject to large errors. Thus, automated systems to obtain RTD curves in laboratory-scale reactors are of great interest for reducing experimental errors due to human interaction, minimizing experimentation costs, and continuously obtaining experimental data. An automated system for obtaining RTD curves in laboratory-scale reactors was designed, built, and tested in this work. During the tests conducted in a cylindrical upflow anaerobic sludge blanket (UASB) reactor, the system worked properly using the stimulus–response pulse technique with sodium chloride as a tracer. Four main factors were found to affect the representativeness of the RTD curves: flow stabilization time, test water conductivity, temperature, and surface tension. A discussion on these factors and the corresponding solutions is presented. The RTD curves of the UASB reactor are left-skewed with a typical tank reactor’s flow shape with channeling and dead zones. A transitory flow behavior was evidenced in the reactor, which indicates the influence of internal turbulent flow structures. The system proposed herein is expected to help study the hydraulics of reactors using laboratory-scale models more efficiently.

show abstract

Section: Temperaturementioning

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Development of an Automated Tracer Testing System for UASB Laboratory-Scale Reactors

Cisneros

Peláez-Samaniego

Pinos-Vélez

et al. 2021

Water

View full text Add to dashboard Cite

show abstract

“…The RTD curves resulting from these tests are presented in Figure 4a. Despite the data dispersion among the obtained RTD curves, their shapes resemble the response of a tank reactor with dead zones and channeling, which is the expected response of a UASB reactor [59]. The dispersion of data among the four tracer tests can be attributed to flow instabilities in the reactor due to dead zones, channeling, and short-circuiting.…”

Section: Tracer Test and Selection Of The Turbulence Modelmentioning

confidence: 83%

Hydrodynamic Evaluation of Five Influent Distribution Systems in a Cylindrical UASB Reactor Using CFD Simulations

Cisneros

Cobos

Peláez-Samaniego

et al. 2021

Water

View full text Add to dashboard Cite

UASB reactors are a promising option for environmentally friendly wastewater treatment due to their reduced carbon footprint and their capacity to treat a variety of wastewater strengths, among other recognized advantages over alternative wastewater treatment systems. The Influent Distribution System (IDS) is a critical structure for generating granules in a UASB reactor since it provides the required flow hydrodynamics for their formation. Thus, the objective of this study was to evaluate and compare the efficiency of five IDS configurations to generate ideal granulation conditions using Computational Fluid Dynamics (CFD) simulations. The IDS configurations were as follows: (C1) single radial inflow, (C2) upward axial inflow, (C3) downward distributed axial inflow, and two novel configurations in the form of (C4) double opposite radial inflow and (C5) downward tangential inflow. The hydrodynamic response of configuration C1 was validated in a physical model with dynamic Froude similitude. The granulation measurement was velocity-based in the reactor reaction zone using steady-state CFD simulations. The novel IDS configuration C4 was the one that resulted in the highest granulation volume, with up to 45.5% of the potential granulation volume of the UASB reactor, in contrast to the IDS C2 that obtained the lowest granulation with only 10.8%. Results confirm that the IDS directly impacts the hydrodynamics of the reactor and that model-based design can be used to ascertain IDS configurations that better promote granulation in UASB reactors.

show abstract

“…The equation (Pe = 2(N − 1)) showed to have a good theoretical basis [28]. In the literature, other researchers [29][30][31][32][33][34][35] also suggested using the same equation. For equal volume reactor systems, the relation between the residence time used in the ADM and that of TISM is given by:…”

Section: Comparison Between Adm and Tismmentioning

confidence: 90%

Acrylonitrile Process Enhancement through Waste Minimization: Effect of Reaction Conditions and Degree of Backmixing

Reesh

2021

Sustainability

View full text Add to dashboard Cite

Waste minimization in reactor design is an effective approach for pollution control, when compared to the traditional practice of the end-of-pipe treatment. Reactor degree of backmixing and operating conditions are important factors that determine the performance of chemical process, including environmental impact. For the purpose of waste minimization, two modeling methods were used for simulating the performance of the acrylonitrile production reactor, based on the ammoxidation of propylene. The effect of residence time, temperature, degree of backmixing on the steady-state propylene conversion, and production of waste were determined. The tanks-in-series model and the axial dispersion model were used to account for the degree of backmixing. The two main by-products in the acrylonitrile process are acetonitrile and hydrogen cyanide, which are both highly toxic waste. Extensive reactor backmixing reduces propylene conversion, especially at high temperature and residence time. Minimum acetonitrile production is favored by low residence time, high to moderate temperature, and no backmixing. Minimum hydrogen cyanide production is favored by low residence time, low temperature, and no backmixing. At 450 °C, the percentage of increase in the selectivity of acrylonitrile, with respect to hydrogen cyanide at plug-flow reactor conditions, as compared to a continuous stirred tank reactor, is 87.1, 74.3, 50.9, 30.4, and 12.4% at a residence time of 1, 2, 4, 6, and 8 s, respectively. The reactor degree of backmixing and operating conditions are important factors that affect the environmental friendliness of the acrylonitrile production process.

show abstract

Comparison of Different Methods for Evaluating the Hydraulics of a Pilot-Scale Upflow Anaerobic Sludge Blanket Reactor

Cited by 7 publications

References 42 publications

Development of an Automated Tracer Testing System for UASB Laboratory-Scale Reactors

Development of an Automated Tracer Testing System for UASB Laboratory-Scale Reactors

Hydrodynamic Evaluation of Five Influent Distribution Systems in a Cylindrical UASB Reactor Using CFD Simulations

Acrylonitrile Process Enhancement through Waste Minimization: Effect of Reaction Conditions and Degree of Backmixing

Contact Info

Product

Resources

About