A UV photodecomposition reactor for siloxane removal from biogas: Modeling aspects

Divsalar, Alireza; Entesari, N.; Dods, Matthew N.; Prosser, Richard W.; Egolfopoulos, Fokion N.; Tsotsis, Theodore T.

doi:10.1016/j.ces.2018.07.048

Cited by 20 publications

(18 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An additional fraction of the radiation is absorbed by the ambient air in between the quartz tube and the reactor enclosure causing additional radiation losses. In the PhoRII configuration, on the other hand, where the lamps are in direct contact with the LFG, all the radiation stays inside the reaction region and, therefore, one expects to observe higher conversion of the siloxane compounds compared to PhoRI, a fact which was previously validated by our modeling simulations …”

Section: Methodssupporting

confidence: 78%

“…Figure shows the conversion of L 2 and D 4 in LFG as a function of siloxane feed concentration in the multi-lamp PhoRI (Figure a) employing again, for comparison purposes, two 41 W UV lamps (G36T5VH Atlantic Ultraviolet Corp.) for LFG feed flow rates similar to those employed in Figure . Modeling studies previously indicated that the PhoRII is significantly more effective than the PhoRI, and the field-testing results validate the modeling studies with the siloxane conversions attained in the PhoRI being significantly lower than those in the PhoRII. One reason for the diminished conversions in the PhoRI is the significantly lower residence times of the LFG in that reactor, since the inside quartz tube through which the gas flows (3.73 cm or 1.47 in.)…”

Section: Resultssupporting

confidence: 67%

“…The need for a cost-effective technique for not only removing siloxanes from biogas but also entirely destroying them has motivated this research group to investigate the use of ultraviolet (UV) radiation to photodecompose the siloxane molecules in order to remove them from biogas. Our group has demonstrated the efficacy of this photodecomposition reactor (PhoR) technology through both laboratory experimental , and modeling studies. The mechanism of siloxane photodegradation involves cleavage of the Si–C bonds in the siloxane molecules at low wavelengths (185 and 254 nm) and the subsequent oxidation of these radicals by nearby oxygen atoms that form from the photolysis of the OO bond in the O 2 molecules the LFG contains (at a level of 3–4% in this field study). , Ozone (O 3 ) also forms as a result of the photolysis of the OO bond, which likely improves the quantum efficiency of the siloxane photodecomposition reaction due to the strong absorption of the UV photons by the O 3 molecules. − It should be noted that even in the absence of oxygen, polysiloxane materials are well-known precursors for SiO 2 ceramics that form via a thermochemical decomposition mechanism rather than a photolytic oxidative one …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Field Testing of a UV Photodecomposition Reactor for Siloxane Removal from Landfill Gas

Divsalar

Dods

et al. 2019

Ind. Eng. Chem. Res.

Self Cite

View full text Add to dashboard Cite

We present in this paper the results of the field testing at a California Landfill of a UV photodecomposition reactor (PhoR) used for the removal of siloxane impurities from landfill gas (LFG). Prior to its field testing, the PhoR technology was tested in the laboratory with simulated LFG and was shown to be capable of completely removing the trace siloxane compounds and to convert them into silica particulates. The key objective of the field test was to validate the ability of the PhoR system to treat real LFG in a practical setting. The field-scale PhoR again proved quite efficient in attaining complete siloxane removal at different concentrations in the real landfill environment. These promising findings have led us to propose a scaled-up, commercial size PhoR system, competitive to conventional adsorption systems that can be practically applied in existing landfill plants to obtain 99+% siloxanes removal rates without associated secondary emissions.

show abstract

Section: Methodssupporting

confidence: 78%

Section: Resultssupporting

confidence: 67%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Field Testing of a UV Photodecomposition Reactor for Siloxane Removal from Landfill Gas

Divsalar

Dods

et al. 2019

Ind. Eng. Chem. Res.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Optimized models can be used for better accuracy. [131][132][133][134][135][136][137][138][139][140][141][142][143][144][145][146][147][148][149]…”

Section: Methodsmentioning

confidence: 99%

A numerical simulation for magnetohydrodynamic nanofluid flow and heat transfer in rotating horizontal annulus with thermal radiation

et al. 2019

View full text Add to dashboard Cite

The impact of an axial magnetic field on the heat transfer and nanofluid flow among two horizontal coaxial tubes in the presence of thermal radiation was considered in this study. The impact of viscous dissipation was also considered. The well-known KKL (Koo-Kleinsteuer-Li) model was applied to approximate the viscosity of the nanofluid and the effective thermal conductivity. Furthermore, proper transformations for the velocity and temperature were applied in this study to obtain a set of ODEs (ordinary differential equations) for basic equations governing the flow, heat and mass transfer. In addition, the 4th order Runge-Kutta (RK) numerical scheme was applied to solve the differential equations along with the associated boundary conditions. The impacts of different parameters, including Hartmann number, Reynolds number, radiation parameter and aspect ratio, on the heat transfer and flow features were studied. According to the results, the value of the Nusselt number increases with an increase in the radiation parameter, Hartmann number and aspect ratio and a decrease in the Reynolds number and Eckert number. Fig. 8 Effect of aspect ratio on the Nusselt number and skin friction coefficient when Pr ¼ 6.8, h ¼ 0.5, Ec ¼ 0.01, Rd ¼ 0.1, Re ¼ 1, f ¼ 0.04.

show abstract

“…Energy production is amongst the most critical challenges for any economic development, and Iran's future progress depends on a rigorous scientific analysis of energy consumption, demand projections, and production from a variety of available sources especially the sustainable and renewable sources such as the tidal energy. 1–5…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation of the effects of immersion on the efficiency of a tidal helical turbine

Rahmani

Biglari

Valipour

et al. 2018

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

In the current study, a two-phase simulation of a tidal helical turbine was performed that contrasts with previous studies in two ways. First, the current research simulated the turbine in different states of immersion in water, whereas previous studies simulated turbines mostly in single-phase conditions and full immersion in water. Second, the present study used a horizontal-axis turbine, whereas previous research employed a vertical-axis helical turbine or Darrius turbine. In this study, a simulation was conducted using the volume of fluid method in ANSYS Fluent 18. Results indicated that the complete immersion of the turbine in water generated a high torque, thereby reducing the efficiency of the device. To determine the conditions with the highest efficiency, immersion rates of 100%, 75%, 50%, and 25% in water were examined, and a configuration with best power coefficient ( C p = 0.175 in TSR = 0.47) was found in 25% immersion. In immersion rate of 25%, resistant pressure on blades was minimum.

show abstract

A UV photodecomposition reactor for siloxane removal from biogas: Modeling aspects

Cited by 20 publications

References 67 publications

Field Testing of a UV Photodecomposition Reactor for Siloxane Removal from Landfill Gas

Field Testing of a UV Photodecomposition Reactor for Siloxane Removal from Landfill Gas

A numerical simulation for magnetohydrodynamic nanofluid flow and heat transfer in rotating horizontal annulus with thermal radiation

Numerical investigation of the effects of immersion on the efficiency of a tidal helical turbine

Contact Info

Product

Resources

About