scholarly journals Valorization of Biomass Residues by Biosorption of Microelements in a Closed-Loop Cycle

Author(s):  
Bartosz Ligas ◽  
Jolanta Warchoł ◽  
Dawid Skrzypczak ◽  
Anna Witek-Krowiak ◽  
Katarzyna Chojnacka

AbstractThe concept of the research data presented assumes the valorization of goldenrod residues from supercritical CO2 extraction following the circular economy principles. The biomass was enriched with microelements (Cr, Zn, Cu) by biosorption from single and multielemental solutions in batch and packed bed reactors. Modeling of biosorption equilibrium supported by instrumental analysis (SEM and FTIR) of material properties was employed to explain the metal ions binding mechanism. The preferential biosorption of Cr(III) over the divalent ions, allows the possibility of valorization of goldenrod residue in a garden-scale biosorption tank acting as a fixed-bed reactor working in an open circulation run and fed with microelements diluted in rainwater. The use of fertigation solution in optimal doses of micronutrients did not show any phytotoxic effect. Using the post-sorptive solution as a source of micronutrients for plants showed significant effects on growth parameters (increased chlorophyll content by 54%) compared to groups fertilized with commercial formulation (13% higher sprout mass). Additionally, fertigation with the post-sorption solution leads to the biofortification of cucumber sprouts. The recycling process results in two products: enriched biomass as a potential feed additive (with Cr(III), Cu(II), and Zn(II)) and a post-sorption solution (with Zn(II) and Cu(II) only) used in the fertigation of plants. Graphical Abstract

1985 ◽  
Vol 50 (10) ◽  
pp. 2122-2133 ◽  
Author(s):  
Jindřich Zahradník ◽  
Marie Fialová ◽  
Jan Škoda ◽  
Helena Škodová

An experimental study was carried out aimed at establishing a data base for an optimum design of a continuous flow fixed-bed reactor for biotransformation of ammonium fumarate to L-aspartic acid catalyzed by immobilized cells of the strain Escherichia alcalescens dispar group. The experimental program included studies of the effect of reactor geometry, catalytic particle size, and packed bed arrangement on reactor hydrodynamics and on the rate of substrate conversion. An expression for the effective reaction rate was derived including the effect of mass transfer and conditions of the safe conversion-data scale-up were defined. Suggestions for the design of a pilot plant reactor (100 t/year) were formulated and decisive design parameters of such reactor were estimated for several variants of problem formulation.


2013 ◽  
Vol 11 (1) ◽  
pp. 569-576 ◽  
Author(s):  
Djamila Djedouani ◽  
Malika Chabani ◽  
Abdeltif Amrane ◽  
Aicha Bensmaili

Abstract Batch experiments were carried out for the adsorption of oxytetracycline (OTC) onto powdered activated carbon (PAC). The operating variables examined were the initial concentration (20–150 mg L−1) and the adsorbent concentration (0.75–1.75 g L−1). As observed increasing the initial concentration, while decreasing the adsorbent dosage, had a positive impact on the amount of OTC uptake (mg g−1). The kinetics was examined in a closed-loop fixed bed adsorber to propose an adsorption mechanism, to understand the dynamic interactions of OTC with ECA08 activated carbon and to predict its fate with time. The sorption results were analyzed using chemical and physical kinetics models. For concentrations lower than 70 mg L−1, the sorption process was found to be controlled by both surface reactions and mass transfer. The average external mass transfer coefficient and intraparticle diffusion coefficient were found to be 0.0051 min−1 and 1.97 mg g−1 min−0.5, respectively. For concentrations higher than 70 mg L−1, mass transfer became rapid and the chemical reaction at the surface of the solid phase was the rate-limiting step. The results showed that the adsorption reaction was accurately described by the pseudo-second-order model.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Piotr Skrzypacz ◽  
Dongming Wei

The nonlinear Brinkman-Forchheimer-Darcy equation is used to model some porous medium flow in chemical reactors of packed bed type. The results concerning the existence and uniqueness of a weak solution are presented for nonlinear convective flows in medium with variable porosity and for small data. Furthermore, the finite element approximations to the flow profiles in the fixed bed reactor are presented for several Reynolds numbers at the non-Darcy’s range.


2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Amit Arora ◽  
Asheesh Kumar ◽  
Gaurav Bhattacharjee ◽  
Chandrajit Balomajumder ◽  
Pushpendra Kumar

Abstract The case for developing novel technologies for carbon dioxide (CO2) capture is fast gaining traction owing to increasing levels of anthropogenic CO2 being emitted into the atmosphere. Here, we have studied the hydrate-based carbon dioxide capture and separation process from a fundamental viewpoint by exploring the use of various packed bed media to enhance the kinetics of hydrate formation using pure CO2 as the hydrate former. We established the fixed bed reactor (FBR) configuration as a superior option over the commonly used stirred tank reactor (STR) setups typically used for hydrate formation studies by showing enhanced hydrate formation kinetics using the former. For the various packing material studied, we have observed silica gel with 100 nm pore size to return the best kinetic performance, corresponding to a water to hydrate conversion of 28 mol% for 3 h of hydrate growth. The fundamental results obtained in the present study set up a solid foundation for follow-up works with a more applied perspective and should be of interest to researchers working in the carbon dioxide capture and storage and gas hydrate fields alike.


2019 ◽  
Vol 3 (2) ◽  
pp. 52 ◽  
Author(s):  
Steffen Flaischlen ◽  
Gregor D. Wehinger

A common reactor type in the chemical and process industry is the fixed-bed reactor. Accurate modeling can be achieved with particle-resolved computational fluid dynamic (CFD) simulations. However, the underlying bed morphology plays a paramount role. Synthetic bed-generation methods are much more flexible and faster than image-based approaches. In this study, we look critically at the two different bed generation methods: Discrete element method (DEM) (in the commercial software STAR-CCM+) and the rigid-body model (in the open-source software Blender). The two approaches are compared in terms of synthetically generated beds with experimental data of overall and radial porosity, particle orientation, as well as radial velocities. Both models show accurate agreement for the porosity. However, only Blender shows similar particle orientation than the experimental results. The main drawback of the DEM is the long calculation time and the shape approximation with composite particles.


Author(s):  
Laércio G. Oliveira ◽  
Ramdayal Swarnakar ◽  
Antonio G. B. de Lima

The fixed-bed reactors of circular cylindrical geometry with heated or cooled walls are frequently used to carry out heterogeneous reactions of solid-gas type in engineering applications. The design of a fixed bed reactor requires an extensive knowledge of heat transfer characteristics within the packed bed. In this sense, this work presents a three-dimensional mathematical model to predict the heat transfer inside a fixed bed elliptical cylinder heat exchanger. The model considers uniform velocity and temperature profiles of the fluid phase at the entrance of the reactor, and constant thermo-physical properties. The surface of the equipment convective boundary condition is assumed to be constant. The energy equation, written in the elliptical cylindrical coordinates, was discretized using a finite-volume method considering a fully implicit formulation, and WUDS interpolation scheme. Numerical results of the dimensionless temperature profiles inside the packed bed reactor at a steady state are presented and temperature distribution is interpreted. To validate the model, numerical results obtained for the circular cylinder are compared with analytical results from literature and a good agreement was obtained.


Author(s):  
Yaidelin A. Manrique ◽  
Carlos V. Miguel ◽  
Diogo Mendes ◽  
Adelio Mendes ◽  
Luis M. Madeira

Abstract In this work the water-gas shift (WGS) process was addressed, with particular emphasis in the development of phenomenological models that can reproduce experimental results in a WGS reactor operating at low temperatures. It was simulated the conversion obtained in a fixed-bed reactor (PBR) packed with a Cu-based catalyst making use of a composed kinetic equation in which the Langmuir-Hinshelwood rate model was used for the lowest temperature range (up to 215 ºC), while for temperatures in the range 215 – 300 ºC a redox model was employed. Several packed-bed reactor models were then proposed, all of them without any fitting parameters. After comparing the simulations against experimental CO conversion data for different temperatures and space time values, it was concluded that the heterogeneous model comprising axial dispersion and mass transfer resistances shows the best fitting. This model revealed also good adherence to other experiments employing different feed compositions (CO and H2O contents); it predicts also the overall trend of increasing CO conversion with the total pressure. This modeling work is particularly important for small scale applications related with hydrogen production/purification for fuel cells.


2011 ◽  
Vol 66 (24) ◽  
pp. 6350-6357 ◽  
Author(s):  
Hamidreza Bakhtiary-Davijany ◽  
Fatemeh Hayer ◽  
Xuyen Kim Phan ◽  
Rune Myrstad ◽  
Peter Pfeifer ◽  
...  

2007 ◽  
Vol 55 (12) ◽  
pp. 75-81 ◽  
Author(s):  
F. Martínez ◽  
M.I. Pariente ◽  
J.A. Melero ◽  
J.A. Botas ◽  
E. Gómez

Iron-containing mesostructured materials (Fe-SBA-15) are suitable for continuous treatment of phenolic aqueous solutions by means of catalytic wet peroxide oxidation (CWPO) in a packed-bed reactor. These materials were successfully extruded, crushed and sieved with a particle size ranging from 1 to 1.6 mm using mineral clay and methyl cellulose as binders. Non-significant changes have been found in the textural and structural properties of the extruded material in comparison to the parent powder Fe-SBA-15 material. Activity of extruded catalyst in terms of phenol degradation and TOC reduction has been monitored in a continuous mode. The increase of residence time enhances significantly the TOC degradation. The catalyst stability, taking into account the loss of iron species from the catalyst into the aqueous solution, has also been examined. The catalytic results of Fe-SBA-15 material in comparison to a homogeneous catalytic test prove the relevant role of the solid catalyst in the oxidation process.


2016 ◽  
Vol 14 (1) ◽  
pp. 7 ◽  
Author(s):  
Iin Parlina ◽  
Lestari Widodo

Along with the development of biogas and its utilization, biogas reactors also evolved from conventional reactor types to high rate performance reactors, adapts to the needs of increased efficiency and also the characteristics of organic waste that is difficult if processed using ordinary reactor. However, this type of reactor basically has 3 types, namely fixed bed (packed-bed, anaerobic filters, fixed-film), fluidized bed reactor, and UASB/ Upflow Anaerobic Sludge Blanket reactor. From these high rate performance reactors, fixed bed reactor is the type that is pretty much developed and implemented in Indonesia, especially for treating organic wastewater from small industries, for example tofu, tapioca and slaughterhouses. Implementation of fixed bed reactor for the tofu industry until today has reached as much as 5 units that serve the needs of about 132 households in Banyumas District, Central Java Province. The fixed bed reactor’s performance is quite high if it is evaluated from biogas yield and the efficiency of the organic content in tofu industry’s wastewater. Implementation, dissemination, and replication of this reactor for treatment of other types of organic waste or other areas have the potential to support government programs in GHG mitigation actions, renewable energy sources provision, environmental protection and the development of energy self-sufficient villages.Keywords : biogas reactor - performance high - rate, fixed bed reactors, tofu industryAbstrakSeiring dengan perkembangan biogas beserta pemanfaatannya, reaktor biogas juga berkembang dari jenis reaktor konvensional hingga reaktor berunjuk kerja tinggi (high rate performance) menyesuaikan dengan kebutuhan peningkatan efisiensi dan juga karakteristik limbah organik yang sulit jika diolah dengan menggunakan reaktor biogas biasa. Namun, pada dasarnya reaktor ini memiliki 3 jenis, yaitu reaktor unggun tetap (fixed bed, packed-bed, anaerobic filter, fixed-film), reaktor unggun terfluidisasi (fluidized bed reactor), dan reaktor UASB (Upflow Anaerobic Sludge Blanket). Dari ketiga jenis reaktor berunjuk kerja tinggi tersebut, reaktor jenis unggun tetap adalah jenis yang cukup banyak dikembangkan dan diimplementasikan di Indonesia, terutama untuk mengolah limbah cair organik yang berasal dari industri kecil, misalnya tahu, tapioka dan rumah potong hewan. Implementasi reaktor unggun tetap untuk industri tahu hingga saat ini telah mencapai jumlah 5 unit reaktor yang melayani kebutuhan sekitar 132 Rumah tangga di Kabupaten Banyumas secara berkelanjutan. Kinerja reaktor unggun tetap ini dapat dikatakan cukup tinggi jika dinilai dari perolehan biogas dan efisiensi penurunan kandungan organic dalam limbah cair tahu. Program implementasi, diseminasi, dan replikasi reaktor ini untuk pengolahan jenis limbah organik yang lain atau daerah lain memiliki potensi dalam mendukung program pemerintah dalam aksi mitigasi Gas Rumah Kaca, penyediaan sumber energi terbarukan, perlindungan lingkungan dan pengembangan desa mandiri energi.Kata kunci : biogas, reaktor high-rate-performance, reaktor fixed bed, industri tahu


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