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Sorption enhanced CO₂ methanation for large scale energy storage: Catalyst and Process development

Wei, L. (author)

<b>Chapter 1</b> is the introduction, which presents thestate of the art in synthesis and application of these, in fact, bi-functionalmaterials for sorption enhanced CO₂ methanation.</p><p class="MsoNormal" style="text-indent:12.5pt">    In <b>Chapter 2</b>, zeolite 13X and 5A supported...

doctoral thesis 2022

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Sorption enhanced catalysis for CO₂ hydrogenation towards fuels and chemicals with focus on methanation

Wei, L. (author), Haije, W.G. (author), Grénman, Henrik (author), de Jong, W. (author)

Hydrogen produced by the electrolysis of water using sustainable electricity will play an increasingly important role as an energy and a feedstock vector. Shifting from fossil to renewable resources means that new industrial platforms have to be set up to provide carbon-based fuels and bulk base chemicals to replace the current fossil...

book chapter 2022

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Fluoride Removal from Groundwater by Mineral-based Materials at Environmentally-relevant Concentrations

Wei, L. (author)

Excessive fluoride (F¯) in drinking water due to natural and anthropogenic activities is a serious health hazard affecting humans worldwide. Groundwater is the major and preferred source of drinking water, also in developing countries. The removal of the excess F^- from groundwater prior to drinking is important in terms of protection...

doctoral thesis 2021

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Fluoride removal from water by Ca-Al-CO₃ layered double hydroxides and simultaneous acidification

Wei, L. (author), Zietzschmann, F.E. (author), Rietveld, L.C. (author), van Halem, D. (author)

Millions of people worldwide are exposed to excessive concentrations of fluoride (F⁻) from groundwater sources. Ca-Al-CO₃ layered double hydroxides (LDHs) have shown promising defluoridation efficiency; however, defluoridation by Ca-Al-CO₃ LDHs is highly pH sensitive. This study showed that simultaneous...

journal article 2021

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Sub-nanometer ceria-promoted Ni 13X zeolite catalyst for CO₂ methanation

Wei, L. (author), Grénman, Henrik (author), Haije, W.G. (author), Kumar, Narendra (author), Aho, Atte (author), Eränen, Kari (author), Wei, L. (author), de Jong, W. (author)

Sub-nanometer zeolite 13X-supported Ni-ceria catalysts were synthesized for CO₂ methanation. XRD and SEM results show the structure and morphology of 13X zeolite after impregnation and calcination. Ce loading affected the catalysts’ metal dispersion, reducibility, basicity and acidity, and thence their activity and selectivity....

journal article 2021

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Removal of Hydrogen Peroxide Residuals and By-Product Bromate from Advanced Oxidation Processes by Granular Activated Carbon

Wang, F. (author), Zhang, Lu (author), Wei, L. (author), van der Hoek, J.P. (author)

During drinking water treatment, advanced oxidation process (AOP) with O3 and H2O2 may result in by-products, residual H2O2 and BrO3−. The water containing H2O2 and BrO3− often flows into subsequent granular activated carbon (GAC) filters. A concentrated H2O2 solution can be used as GAC modification reagent at 60 °C to improve its adsorption...

journal article 2021

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Pure methane from CO₂ hydrogenation using a sorption enhanced process with catalyst/zeolite bifunctional materials

Wei, L. (author), Azad, Hamza (author), Haije, W.G. (author), Grenman, L.O.H. (author), de Jong, W. (author)

Methanation is a potential large-scale option for CO₂ utilization, and it is one of the solutions for decreasing carbon emission and production of synthetic green fuels. However, the CO₂ conversion is limited by thermodynamics in conventional reaction conditions. However, around 100 % conversion can be obtained using...

journal article 2021

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Comparative study of low-cost fluoride removal by layered double hydroxides, geopolymers, softening pellets and struvite

Wei, L. (author), Li, Z. (author), Ye, G. (author), Rietveld, L.C. (author), van Halem, D. (author)

Excessive F^- in drinking water due to natural and anthropogenic activities is a serious health hazard affecting humans worldwide. In this study, a comparative assessment was made of eight mineral-based materials with advantageous structural properties for F^- uptake: layered-double-hydroxides (LDHs), geopolymers,...

journal article 2021

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Influence of nickel precursors on the properties and performance of Ni impregnated zeolite 5A and 13X catalysts in CO₂ methanation

Wei, L. (author), Haije, W.G. (author), Kumar, Narendra (author), Peltonen, Janne (author), Peurla, Markus (author), Grenman, L.O.H. (author), de Jong, W. (author)

Zeolite 13X and 5A supported Ni catalysts were synthesized for CO₂ methanation using the evaporation impregnation method. The influence of using different Ni precursors (nitrate, citrate, and acetate) as well as calcination temperatures on the catalyst properties and performance were investigated. XRD, SEM-EDX, TEM, STEM-EDX, N<sub...

journal article 2020

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Can bi-functional nickel modified 13X and 5A zeolite catalysts for CO₂ methanation be improved by introducing ruthenium?

Wei, L. (author), Kumar, Narendra (author), Haije, W.G. (author), Peltonen, Janne (author), Peurla, Markus (author), Grenman, L.O.H. (author), de Jong, W. (author)

Zeolites 13X and 5A were modified with nickel and/or ruthenium for CO₂ methanation. The catalysts were prepared by evaporation impregnation and XRD, SEM-EDX, TEM, STEM-EDX, nitrogen physisorption, H₂-TPR and NH₃-TPD were used to characterize the physico-chemical properties of the catalysts. The physico...

journal article 2020

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Fluoride removal by Ca-Al-CO₃ layered double hydroxides at environmentally-relevant concentrations

Wei, L. (author), Zietzschmann, F.E. (author), Rietveld, L.C. (author), van Halem, D. (author)

In this study, F⁻ removal by Ca–Al–CO₃ layered double hydroxides (LDHs) was investigated at environmentally-relevant concentration ranges (2–12 mg/L) to below the WHO guideline, with an emphasis on the effect of LDHs’ modification, as well as the effects of initial F⁻ concentration, adsorbent dose, pH,...

journal article 2020

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Scattering control of optical nano-antennas with designed excitations

Wei, L. (author)

doctoral thesis 2018

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Adding a spin to Kerker’s condition: angular tuning of directional scattering with designed excitation

Wei, L. (author), Bhattacharya, N. (author), Urbach, Paul (author)

We describe a method to control the directional scattering of a high-index dielectric nanosphere, which utilizes the unique focusing properties of an azimuthally polarized phase vortex and a radially polarized beam to independently excite inside the nanosphere a spinning magnetic dipole and a linearly polarized electric dipole mode normal to the...

journal article 2017

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Efficiency of multi-beam Fourier phase gratings at 1.4 THz

Mirzaei, B. (author), Silva, J. R.G. (author), Luo, Y. (author), Liu, X. X. (author), Wei, L. (author), Hayton, Darren J. (author), Gao, J.R. (author), Groppi, C (author)

We compare the results of simulated and measured power efficiency and far-field beam pattern, for two reflective Fourier phase gratings, designed to generate 2 x 2 and 2 x 4 beams respectively from a single-beam, coherent source at 1.4 THz. The designed surface structures were manufactured on aluminum plates by a computer numerical control ...

journal article 2017

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Accurate Feeding of Nanoantenna by Singular Optics for Nanoscale Translational and Rotational Displacement Sensing

Xi, Z. (author), Wei, L. (author), Adam, A.J.L. (author), Urbach, Paul (author), Du, L (author)

Identifying subwavelength objects and displacements is of crucial importance in optical nanometrology. We show in this Letter that nanoantennas with subwavelength structures can be excited precisely by incident beams with singularity. This accurate feeding beyond the diffraction limit can lead to dynamic control of the unidirectional scattering...

journal article 2016

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Stretchable Binary Fresnel Lens for Focus Tuning

Li, X. (author), Wei, L. (author), Poelma, René H. (author), Vollebregt, S. (author), Wei, J. (author), Urbach, Paul (author), Sarro, Pasqualina M (author), Zhang, Kouchi (author)

This paper presents a tuneable binary amplitude Fresnel lens produced by wafer-level microfabrication. The Fresnel lens is fabricated by encapsulating lithographically defined vertically aligned carbon nanotube (CNT) bundles inside a polydimethyl-siloxane (PDMS) layer. The composite lens material combines the excellent optical absorption...

journal article 2016

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Efficient computation of the spontaneous decay rate of arbitrarily shaped 3D nanosized resonators: A Krylov model-order reduction approach

Zimmerling, J.T. (author), Wei, L. (author), Urbach, H.P. (author), Remis, R.F. (author)

We present a Krylov model-order reduction approach to efficiently compute the spontaneous decay (SD) rate of arbitrarily shaped 3D nanosized resonators. We exploit the symmetry of Maxwell’s equations to efficiently construct so-called reduced-order models that approximate the SD rate of a quantum emitter embedded in a resonating nanostructure....

journal article 2016

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Shaping the focal field of radially/azimuthally polarized phase vortex with Zernike polynomials

Wei, L. (author), Urbach, Paul (author)

The focal field properties of radially/azimuthally polarized Zernike polynomials are studied. A method to design the pupil field in order to shape the focal field of radially or azimuthally polarized phase vortex is introduced. With this method, we are able to obtain a pupil field to achieve a longitudinally polarized hollow spot with a depth of...

journal article 2016

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A 2 × 2 array receiver at 1.4 THz based on HEB mixers and a Fourier phase grating local oscillator

Liu, X.X. (author), Hayton, D.J. (author), Luo, Y.C. (author), Wei, L. (author), Vercruyssen, N. (author), Gao, J.R. (author), Groppi, C. (author)

We report on realization of a 2 × 2 NbN hot electron bolometer (HEB) array receiver using multiple local oscillator (LO) beams that are obtained from a Fourier phase grating mirror. The grating splits a 1.4 THz single beam into four uniform sub-beams. Two 50mm lenses are applied to collimate each beam in order to achieve a spacing of 12mm...

conference paper 2015

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Fourier phase grating for THz multi-beam local oscillators

Luo, Y.C. (author), Liu, X.X. (author), Hayton, D.J. (author), Wei, L. (author), Gao, J.R. (author), Groppi, C. (author)

A Fourier phase grating mirror will be applied to split a single, coherent terahertz source beam into multi-beams, which are spatially distributed as required for the local oscillator in an array receiver. We report on the simulation, design and fabrication of a Fourier phase grating at 1.25 THz for generating 2×2 beams, and the measurements at...

conference paper 2015