Fluidized Bed Reactor Technology Research Articles

Assessment of amoxicillin biodegradation using a fluidized bed reactor

In recent decades, emerging pharmaceutical contaminants, such as personal care items, pharmaceuticals, and disinfectants, have increased alarmingly in aquatic ecosystems. The efficacy of wastewater treatment plants in eliminating these contaminants has been demonstrated. This study aims to find an alternative method, such as using the fluidized bed reactor (FBR) with bacteria to remove amoxicillin from wastewater. The active bacteria Acinetobacter baumannii and Klebsiella pneumoniae were isolated from one of the pharmaceutical factories in Baghdad, Iraq, from Al-Jazeera wastewater, which was used in FBR technology to decompose the antibiotic amoxicillin. The study examined several operational parameters, including pH, total organic carbon (TOC), dissolved carbon dioxide (CO2) concentration, airflow rate, amoxicillin concentration, and bacterial number, while maintaining a constant temperature. High-performance liquid chromatography (HPLC) was used to find the reaction route. The maximum amoxicillin removal efficiency was 93% and 91% for Acinetobacter baumannii and Klebsiella pneumoniae, respectively. For both bacterial species, the pH decreased due to the formation of amino acids and CO2. The suitable operation condition was 5 mg/L of amoxicillin concentration, flow rate of 30 m/s, and the number of bacteria 47 x 105 cfm/mL and 40 x 105 cfm/mL for Acinetobacter baumannii and Klebsiella pneumoniae, respectively. After treatment, the number of bacteria increased due to the degradation of amoxicillin. The steady-state time is found at 64 hours. The organic matter reaction pathway ends at the aromatic amino acid lysine, which kills gram-negative bacteria. This method was found to be successful in removing amoxicillin in low concentrations by using Acinetobacter baumannii. In the future, treating amoxicillin in wastewater using FBR technology with gram-positive bacteria is recommended.

Application of low-solubility dolomite as seed material for phosphorus recovery from synthetic wastewater using fluidized-bed crystallization (FBC) technology

Fluidized-bed reactor technology was applied to recover phosphorus from solution via crystallization in a seeded (FBC, Fluidized-bed Crystallization) and unseeded (FBHC, Fluidized-bed Homogeneous Crystallization) system. Dolomite (CaMg(CO3)2) is applied as seed material to provide an existing surface in the seeded crystallization system. Under the optimum pH of 7.7, the presence of seed material in the FBC system enhanced the crystallization ratio of both phosphorus and calcium from 60% to 80%. The operating parameters, including - effluent pHe, up-flow velocity (U, m h−1), and cross-sectional loading (L, kg m−2 hr−1) were optimized in the FBC system. Under optimum conditions at pH 7.7, molar ratio of [Ca]0/[P]0=3.5/1, up-flow rate of 30 m h−1, and cross-sectional loading of 0.9 kg m−2 hr−1, the crystallization ratio (CR) and total removal (TR) of both phosphorus and calcium reached 85% and 92%, respectively. Based on the XRD and Raman pattern, it was confirmed the solid products consist of tricalcium phosphate (Ca3(PO4)2·xH2O) from both FBC and FBHC processes. An economic analysis shows that the disposal cost could be reduced from 0.92 US$ wastewater to 0.2 US$/m3. Phosphorus, encapsulated in a sparingly soluble crystalline form such as dolomite in the FBC system can be potentially used as a slow-release fertilizer and raw material for bio-ceramic and bioactive glass.

High-yield production of aromatics from methanol using a temperature-shifting multi-stage fluidized bed reactor technology

We propose a temperature-shifting three-stage fluidized bed reactor technology for the consecutive conversion of methanol and its intermediate products into aromatics. The first stage served the aromatization of methanol. The second stage served the aromatization of the intermediates of light paraffins and olefins. The third stage served the alkylation of residual olefins. The yield of the aromatics was relatively stable within 12 h in the exit of third stage and was 6–12% higher than that in the exit of first stage. The increased yield of aromatics was attributed to the effective transformation of intermediate products (C2-C5 hydrocarbons). The final alkenes/alkanes ratio dropped to only 0.03. The time-dependent yields of aromatics, olefins and paraffins were analyzed in detail based on the information of coke at different stages. The results provide insight into the consecutive conversion network of methanol into aromatics.

Enhanced production of aromatics from propane with a temperature-shifting two-stage fluidized bed reactor.

A temperature-shifting two-stage fluidized bed reactor technology was used to convert propane and its intermediate products into aromatics. The first stage served for the aromatization of propane with a Ga/ZSM-5 catalyst at 570 °C. The second stage served for the alkylation of the intermediates of olefins at 300 °C. The increased yield of aromatics was attributed to the effective transformation of C2–C3 olefins as well as due to the suppression of the hydrogen transfer effect of the olefins.

FBR Technology: Its Potential Application on Reuse of Industrial Wastewater

The treatment performance of the fluidized-bed Fenton process in terms of COD and color removal efficiency on a textile wastewater from a manu­facturing facility in Southern Taiwan was evaluated as a case study for the poten­tial application of fluidized-bed reactor (FBR) technology on reuse of industrial wastewater. Results showed that the effluent COD and color of the textile wastewater met the regulatory requirements of Taiwan when the following con­ditions were used in the treatment: concentration ratio COD:Fe 2+ :H 2 O 2 = 1:0.95:7.94, carrier = 74.07 g/l, initial pH = 3. The COD and color removal effi­ciency of the fluidized-bed Fenton process for synthetic commercial dyeing wastewater and actual textile wastewater were compared. At optimum pH =3, the fluidized-bed Fenton process can remove COD more easily from the commercial dye than from actual textile wastewater. In the case of color removal, the fluid­ized-bed Fenton had high removal efficiency. This study has shown that the fluid­ized-bed Fenton process can not only treat textile waste water to meet Taiwan’s regulatory limits for COD and color but also has the potential to be a technology on reuse of industrial wastewater

Phase transformation characterization of olivine subjected to high temperature in air

Abstract Olivine is one of the well-suited materials for fluidized bed reactor technology. After calcination at high temperature, olivine undergoes phase transformations resulting in dehydration and oxidation of fayalite to hematite and magnetite. The transformation mechanisms of olivine subjected to a calcination process at 1400 °C for 4 h are studied. Calcined olivine is characterized by X-Ray Diffraction (XRD), in situ XRD at varying temperatures and Raman spectroscopy. This paper explains the contribution of Raman spectroscopy to the study of iron oxide with regard to XRD. The heterogeneous distribution of hematite, magnetite and forsterite in the calcined material is exhibited by Raman mapping.

Ex situ treatment of N-nitrosodimethylamine (NDMA) in groundwater using a fluidized bed reactor

N-nitrosodimethylamine (NDMA) is a suspected human carcinogen that has traditionally been treated in water using ultraviolet irradiation (UV). The objective of this research was to examine the application of a laboratory-scale fluidized bed reactor (FBR) as an alternative technology for treating NDMA to part-per-trillion (ng/L) concentrations in groundwater. Previous studies have shown that the bacterium Rhodococcus ruber ENV425 is capable of cometabolizing NDMA during growth on propane as a primary substrate in batch culture (Fournier et al., 2009) and in a bench-scale membrane bioreactor (Hatzinger et al., 2011) to low ng/L concentrations. R. ruber ENV425 was inoculated into the FBR during this study. With a hydraulic residence time (HRT) of 20 min, the FBR was found to be an effective means to treat 10–20 μg/L of NDMA to effluent concentrations less than 100 ng/L. When the HRT was increased to 30 min and oxygen and propane addition rates were optimized, the FBR system demonstrated treatment of the NDMA to effluent concentrations of less than 10 ng/L. Short-term shutdowns and the presence of trichloroethene (TCE) at 6 μg/L as a co-contaminant had minimal effect on the treatment of NDMA in the FBR. The data suggest that the FBR technology can be a viable alternative to UV for removing NDMA from groundwater.

Physicochemical changes in Miscanthus ash on agglomeration with fluidized bed material

Biomass gasification is more suitable than combustion for Combined Heat and Power (CHP) applications. In this field, fluidized bed reactor technology ensures good mixing of continuously fed fuel and provides homogeneous temperature distribution in the reactor. The aim of the gasification is to produce clean syngas, thus it is important to investigate the influence of various operating conditions on the property of gas products and tar evolution. Usually, temperature and catalytic bed composition are the most studied parameters. In spite of the advantages of fluidized beds, biomass gasification suffers from technical problems such as slagging and fouling due to the high ash content and the formation of low melting point compounds and eutectic composition. The understanding of bed agglomeration requires the investigation of natural phases of biomass mineral matter and bed material. Due to the abundance of ash in biomass and its low degree of crystallization, supplementary methods have to be used beside XRD, LA-ICP-MS and SEM–EDX analysis to characterise interactions between ashes and fluidized bed material.

Pyrolysis of wheat straw-derived organosolv lignin

The cost-effectiveness of a lignocellulose biorefinery may be improved by developing applications for lignin with a higher value than application as fuel. We have developed a pyrolysis based lignin biorefinery approach, called LIBRA, to transform lignin into phenolic bio-oil and biochar using bubbling fluidized bed reactor technology. The bio-oil is a potential source for value-added products that can replace petrochemical phenol in wood-adhesives, resins and polymer applications. The biochar can e.g. be used as a fuel, as soil-improver as solid bitumen additive and as a precursor for activated carbon. In this paper we applied the pyrolysis-based LIBRA concept for the valorisation of wheat straw-derived organosolv lignin. First, we produced lignin with a high purity from two wheat straw varieties, using an organosolv fractionation approach. Subsequently, we converted these lignins into bio-oil and biochar by pyrolysis. For comparison purposes, we also tested two reference lignins, one from soda-pulping of a mixture of wheat straw and Sarkanda grass (Granit) and one from Alcell organosolv fractionation of hardwoods. Results indicate that ∼80 wt% of the dry lignin can be converted into bio-oil (with a yield of 40–60%) and biochar (30–40%). The bio-oil contains 25–40 wt% (based on the dry lignin weight) of a phenolic fraction constituting of monomeric (7–11%) and oligomeric (14–24%) components. The monomeric phenols consist of guaiacols, syringols, alkyl phenols, and catechols. 4-vinylguaiacol is the major phenolic monomer that is formed during the pyrolysis of the straw lignins in yields from 0.5–1 wt%. For the hardwood-lignin Alcell, the predominant phenol is 4-methylsyringol (1.2 wt%). The ratio guaiacols/syringols seems to be an indicative marker for the source of the lignin.

Polysilicon Materials FBR Technology for Solar and Semiconductor Silicon

The chaotic nature of fluid flow within a fluidized bed reactor (FBR), the high surface area of the product which requires special handling to prevent contamination, the size of the reactors and the construction materials present significant engineering challenges, but, once overcome the benefits of the FBR polysilicon production are significant. FBR technology can used with either silane or TCS feed. In this paper, the reaction paths for silane conversion are discussed. Sophisticated predictive modeling and simulation capabilities allow optimization of both reactor design and operating conditions to maximize productivity and reduce reactor downtime. These attributes enable production of high purity polysilicon for both the solar and the semiconductor industries.

Biological Fluidized Bed Reactor Technology: The Optimal Approach for Treatment of Perchlorate Contaminated Groundwater or Drinking Water

Biological Fluidized Bed Reactor Technology: The Optimal Approach for Treatment of Perchlorate Contaminated Groundwater or Drinking WaterThe perchlorate anion has been detected in the drinking water of millions of people living in the U.S. often at concentrations above the level safe for human consumption. Ex-situ biotreatment has been utilized for perchlorate reduction at concentrations even below 100 ug/l. The principal objectives of this paper were to compare various bioreactor configurations in the treatment of low strength...Author(s)Paul M. SuttonSourceProceedings of the Water Environment FederationSubjectSession 8: BAF's, Fixed and Fluid BedsDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2010ISSN1938-6478SICI1938-6478(20100101)2010:7L.539;1-DOI10.2175/193864710798208683Volume / Issue2010 / 7Content sourceResiduals and Biosolids ConferenceFirst / last page(s)539 - 549Copyright2010Word count226Subject keywordsBiological fluidized bedperchloratenitrate

Perspectives for Fluidized Bed Nuclear Reactor Technology using Rotating Fluidized Beds in a Static Geometry

The new concept of a rotating fluidized bed in a static geometry opens perspectives for fluidized bed nuclear reactor technology and is experimentally and numerically investigated. With conventional fluidized bed technology, the maximum attainable power is rather limited and maximum at a certain fluidization gas flow rate. Using a rotating fluidized bed in a static geometry, the fluidization gas drives both the centrifugal force and the counteracting radial gas-solid drag force in a similar way. This allows operating the reactor at any chosen sufficiently high solids loading over a much wider fluidization gas flow rate range and in particular at much higher fluidization gas flow rates than with conventional fluidized bed reactor technology, offering increased flexibility with respect to cooling via the fluidization gas. Furthermore, the centrifugal force can be a multiple of earth gravity, allowing radial gas-solid slip velocities much higher than in conventional fluidized beds. The latter result in gas-solid heat transfer coefficients one or multiple orders of magnitude higher than in conventional fluidized beds. The combination of dense operation and high fluidization gas flow rates allows process intensification and a more compact reactor design.

Laboratory-scale evaluation of fluidized bed reactor technology for biotreatment of maleic anhydride process wastewater

Fluidized bed reactor (FBR) technology has emerged in recent years as an attractive approach for the biotreatment of chemical industry wastestreams. A laboratory-scale FBR study was conducted to investigate the feasibility of utilizing FBR technology for the biotreatment of maleic anhydride wastewater generated during manufacturing operations. The maleic anhydride wastestream contains a mixture of maleic acid, fumaric acid, phthalic acid and di-n-butylphthalate (DBP). The FBR removed >98% of chemical oxygen demand (COD) and total organic carbon (TOC) from the wastewater at a chemical loading rate of 4.86 kg of COD m−3 bed day−1. Maleic acid, fumaric acid or phthalic acid were not detected in the FBR effluent indicating removal of these diacids. Residues of DBP adsorbed to granular activated carbon (GAC) stabilized at low levels indicating that the >99% removal efficiency for DBP in the FBR resulted from microbial degradation. Solids measurements showed microbial biomass levels on the GAC ranging from 10500 to 32400 mg L−1 and effluent solids production ranged from 0.027 to 0.041 kg solids kg−1 COD treated. This laboratory-scale study demonstrated that FBR technology was highly effective for the biotreatment of the maleic anhydride wastestream and may offer several advantages over traditional activated sludge systems.

Economic assessment of ethanol production comparing traditional and fluidized-bed bioreactors

This study analyzes the economic impact that a fluidized-bed reactor (FBR) using immobilizedZymomonas mobilis would have on a plant converting cornstarch into ethanol. The study addresses substituting this new technology into an existing plant or using it for a new plant. We have compared the processing steps required by the FBR with conventional technology, and developed process flow schematics, priced required equipment, and generated plant capital and operating cost estimates. This allowed a cost evaluation between the FBR and traditional technologies, such as well-mixed fed-batch fermentation. The study results indicate that the FBR technology can provide a significant reduction in the production costs of ethanol—a savings of >$0.02/gal if inserted into an existing plant, and a savings of >$0.06/gal if used at a new plant.