Search results for: chemical reactor

Authors: Sergio Rapagnà, Alessandro Antonio Papa, Armando Vitale, Andre Di Carlo

Abstract:

In recent years the world population has enormously increased the use of plastic products for their living needs, in particular for transporting and storing consumer goods such as food and beverage. Plastics are widely used in the automotive industry, in construction of electronic equipment, clothing and home furnishings. Over the last 70 years, the annual production of plastic products has increased from 2 million tons to 460 million tons. About 20% of the last quantity is mismanaged as waste. The consequence of this mismanagement is the release of plastic waste into the terrestrial and marine environments which represents a danger to human health and the ecosystem. Recycling all plastics is difficult because they are often made with mixtures of polymers that are incompatible with each other and contain different additives. The products obtained are always of lower quality and after two/three recycling cycles they must be eliminated either by thermal treatment to produce heat or disposed of in landfill. An alternative to these current solutions is to obtain a mixture of gases rich in H₂, CO and CO₂ suitable for being profitably used for the production of chemicals with consequent savings fossil sources. Obtaining a hydrogen-rich syngas can be achieved by gasification process using the fluidized bed reactor, in presence of steam as the fluidization medium. The fluidized bed reactor allows the gasification process of plastics to be carried out at a constant temperature and allows the use of different plastics with different compositions and different grain sizes. Furthermore, during the gasification process the use of steam increase the gasification of char produced by the first pyrolysis/devolatilization process of the plastic particles. The bed inventory can be made with particles having catalytic properties such as olivine, capable to catalyse the steam reforming reactions of heavy hydrocarbons normally called tars, with a consequent increase in the quantity of gases produced. The plant is composed of a fluidized bed reactor made of AISI 310 steel, having an internal diameter of 0.1 m, containing 3 kg of olivine particles as a bed inventory. The reactor is externally heated by an oven up to 1000 °C. The hot producer gases that exit the reactor, after being cooled, are quantified using a mass flow meter. Gas analyzers are present to measure instantly the volumetric composition of H₂, CO, CO₂, CH₄ and NH₃. At the conference, the results obtained from the continuous gasification of polypropylene (PP) particles in a steam atmosphere at temperatures of 840-860 °C will be presented.

Keywords: gasification, fluidized bed, hydrogen, olivine, polypropyle

Procedia PDF Downloads 23

Authors: Eusebio A. Jiménez-Arévalo, Deifilia Ahuatzi-Chacón, Juvencio Galíndez-Mayer, Cleotilde Juárez-Ramírez, Nora Ruiz-Ordaz

Abstract:

Bendiocarb is a known toxic xenobiotic that presents acute and chronic risks for freshwater invertebrates and estuarine and marine biota; thus, the treatment of water contaminated with the insecticide is of concern. In this paper, a bacterial community with the capacity to grow in bendiocarb as its sole carbon and nitrogen source was isolated by enrichment techniques in batch culture, from samples of a composting plant located in the northeast of Mexico City. Eight cultivable bacteria were isolated from the microbial community, by PCR amplification of 16 rDNA; Pseudoxanthomonas spadix (NC_016147.2, 98%), Ochrobacterium anthropi (NC_009668.1, 97%), Staphylococcus capitis (NZ_CP007601.1, 99%), Bosea thiooxidans. (NZ_LMAR01000067.1, 99%), Pseudomonas denitrificans. (NC_020829.1, 99%), Agromyces sp. (NZ_LMKQ01000001.1, 98%), Bacillus thuringiensis. (NC_022873.1, 97%), Pseudomonas alkylphenolia (NZ_CP009048.1, 98%). NCBI accession numbers and percentage of similarity are indicated in parentheses. These bacteria were regarded as the isolated species for having the best similarity matches. The ability to degrade bendiocarb by the immobilized bacterial community in a packed bed biofilm reactor, using as support volcanic stone fragments (tezontle), was evaluated. The reactor system was operated in batch using mineral salts medium and 30 mg/L of bendiocarb as carbon and nitrogen source. With this system, an overall removal efficiency (η_bend) rounding 90%, was reached.

Keywords: bendiocarb, biodegradation, biofilm reactor, carbamate insecticide

Procedia PDF Downloads 275

Authors: Franco Ferrucci, Driss Stitou, Pascal Ortega, Franck Lucas

Abstract:

The energy situation in tropical insular regions, as found in the French Polynesian islands, presents a number of challenges, such as high dependence on imported fuel, high transport costs from the mainland and weak electricity grids. Alternatively, these regions have a variety of renewable energy resources, which favor the exploitation of smart microgrids and energy storage technologies. With regards to the electrical energy demand, the high temperatures in these regions during the entire year implies that a large proportion of consumption is used for cooling buildings, even during the evening hours. In this context, this paper presents an air conditioning system driven by photovoltaic (PV) electricity that combines a refrigeration system and a thermochemical storage process. Thermochemical processes are able to store energy in the form of chemical potential with virtually no losses, and this energy can be used to produce cooling during the evening hours without the need to run a compressor (thus no electricity is required). Such storage processes implement thermochemical reactors in which a reversible chemical reaction between a solid compound and a gas takes place. The solid/gas pair used in this study is BaCl2 reacting with ammonia (NH3), which is also the coolant fluid in the refrigeration circuit. In the proposed system, the PV-driven electric compressor is used during the daytime either to run the refrigeration circuit when a cooling demand occurs or to decompose the ammonia-charged salt and remove the gas from thermochemical reactor when no cooling is needed. During the evening, when there is no electricity from solar source, the system changes its configuration and the reactor reabsorbs the ammonia gas from the evaporator and produces the cooling effect. In comparison to classical PV-driven air conditioning units equipped with electrochemical batteries (e.g. Pb, Li-ion), the proposed system has the advantage of having a novel storage technology with a much longer charge/discharge life cycle, and no self-discharge. It also allows a continuous operation of the electric compressor during the daytime, thus avoiding the problems associated with the on-off cycling. This work focuses on the system concept and on the efficiency study of its main components. It also compares the thermochemical with electrochemical storage as well as with other forms of thermal storage, such as latent (ice) and sensible heat (chilled water). The preliminary results show that the system seems to be a promising alternative to simultaneously fulfill cooling and energy storage needs in tropical insular regions.

Keywords: microgrid, solar air-conditioning, solid/gas sorption, thermochemical storage, tropical and insular regions

Procedia PDF Downloads 235

Authors: T. Jayanthi, K. Velusamy, H. Seetha, S. A. V. Satya Murty

Abstract:

Verification and Validation of Simulated Process Model is the most important phase of the simulator life cycle. Evaluation of simulated process models based on Verification and Validation techniques checks the closeness of each component model (in a simulated network) with the real system/process with respect to dynamic behaviour under steady state and transient conditions. The process of Verification and validation helps in qualifying the process simulator for the intended purpose whether it is for providing comprehensive training or design verification. In general, model verification is carried out by comparison of simulated component characteristics with the original requirement to ensure that each step in the model development process completely incorporates all the design requirements. Validation testing is performed by comparing the simulated process parameters to the actual plant process parameters either in standalone mode or integrated mode. A Full Scope Replica Operator Training Simulator for PFBR - Prototype Fast Breeder Reactor has been developed at IGCAR, Kalpakkam, INDIA named KALBR-SIM (Kalpakkam Breeder Reactor Simulator) wherein the main participants are engineers/experts belonging to Modeling Team, Process Design and Instrumentation and Control design team. This paper discusses the Verification and Validation process in general, the evaluation procedure adopted for PFBR operator training Simulator, the methodology followed for verifying the models, the reference documents and standards used etc. It details out the importance of internal validation by design experts, subsequent validation by external agency consisting of experts from various fields, model improvement by tuning based on expert’s comments, final qualification of the simulator for the intended purpose and the difficulties faced while co-coordinating various activities.

Keywords: Verification and Validation (V&V), Prototype Fast Breeder Reactor (PFBR), Kalpakkam Breeder Reactor Simulator (KALBR-SIM), steady state, transient state

Procedia PDF Downloads 261

Authors: A. Benhadji, M. Taleb Ahmed

Abstract:

Among the various methods of treatment, advanced oxidation processes (AOP) are the most promising ones. In this study, Peroxi Electrocoagulation Process (PEP) was investigated for the treatment of detergent wastewater. The process was compared with electrooxidation treatment. The results showed that chemical oxygen demand (COD) was high 7584 mgO₂.L^-1, while the biochemical oxygen demand was low (250 mgO₂.L^-1). This wastewater was hardly biodegradable. Electrochemical process was carried out for the removal of detergent using a glass reactor with a volume of 1 L and fitted with three electrodes. A direct current (DC) supply was used. Samples were taken at various current density (0.0227 A/cm² to 0.0378 A/cm²) and reaction time (1-2-3-4 and 5 hour). Finally, the COD was determined. The results indicated that COD removal efficiency of PEP was observed to increase with current intensity and reached to 77% after 5 h. The highest removal efficiency was observed after 5 h of treatment.

Keywords: AOP, COD, detergent, PEP, wastewater

Procedia PDF Downloads 116

Authors: M. Abdur Rashid Sarkar, Riffat Mahmud

Abstract:

Boiling heat transfer plays a crucial role in cooling nuclear reactor for safe electricity generation. A two phase flow is susceptible to thermal-hydrodynamic instabilities, which may cause flow oscillations of constant amplitude or diverging amplitude. These oscillations may induce boiling crisis, disturb control systems, or cause mechanical damage. Based on their mechanisms, various types of instabilities can be classified for a nuclear reactor. From a practical engineering point of view one of the major design difficulties in dealing with multiphase flow is that the mass, momentum, and energy transfer rates and processes may be quite sensitive to the geometric configuration of the heat transfer surface. Moreover, the flow within each phase or component will clearly depend on that geometric configuration. The complexity of this two-way coupling presents a major challenge in the study of multiphase flows and there is much that remains to be done. Yet, the parametric effects on flow instability such as the effect of aspect ratio, pressure drop, channel length, its orientation inlet subcooling and surface roughness etc. have been analyzed. Another frequently occurring instability, known as the Kelvin–Helmholtz instability has been briefly reviewed. Various analytical techniques for predicting parametric effect on the instability are analyzed in terms of their applicability and accuracy.

Keywords: two phase flows, boiling crisis, thermal-hydrodynamic instabilities, water cooled nuclear reactors, kelvin–helmholtz instability

Procedia PDF Downloads 395

Authors: Bharat Kumar, Deepak Kumar, Vijay Chaudhry

Abstract:

Zirconium alloys are widely used for the core components of a pressurized heavy water reactor (PHWR) or Canada deuterium (CANDU) reactor due to their low neutron absorption cross-section and excellent mechanical properties. The components made of Zirconium alloys are subjected to flow-induced vibrations, resulting in fretting wear at the interface of; pressure tubes and bearing pads, pressure tubes and calandria tubes, and calandria tubes and Liquid injection shutdown system (LISS) nozzles. There is a need to explore the tribological response under such conditions. Present work simulates the contact between calandria tube and LISS nozzle of PHWR/CANDU reactor as cylinder-on-cylinder contact configuration. Reciprocating tribo-tests were conducted on Zircaloy-4 (Zr-4) under the self-mated condition at varying amplitude, frequency, and sliding time. To understand the active wear mechanism, worn surfaces were analyzed using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The change in amplitude severely affects the wear than other factors. The wear mechanism transits from adhesion to abrasion with increasing test amplitude. The dominant wear mechanisms are micro-cutting and micro-plowing followed by delamination in some areas. However, the coefficient of friction has indifferent behaviors.

Keywords: zircaloy-4, tribology, calandria tube, LISS nozzle, PHWR

Procedia PDF Downloads 200

Authors: K. Shahril, A. Nizam, M. Sabri, A. Siti Rohana, H. Salmah

Abstract:

Chemical modifier (Acrylic Acid) is used as filler treatment to improve mechanical properties and swelling behavior of polypropylene/coconut fiber (PP/CF) composites by creating more adherent bonding between CF filler and PP Matrix. Treated (with chemical modifier) and untreated (without chemical modifier) composites were prepared in the formulation of 10 wt%, 20 wt%, 30 wt%, and 40 wt%. The mechanical testing indicates that composite with 10 wt% of untreated composite has the optimum value of tensile strength, and the composite with chemical modifier shows the tensile strength was increased. By increasing of filler loading, elastic modulus was increased while the elongation at brake was decreased. Meanwhile, the swelling test discerned that the increase of filler loading increased the water absorption of composites and the presence of chemical modifier reduced the equilibrium water absorption percentage.

Keywords: coconut fiber, polypropylene, acid acrylic, ethanol, chemical modifier, composites

Procedia PDF Downloads 458

Authors: Yazan M. Alatrash, Han-ok Kang, Hyun-gi Yoon, Shen Zhang, Juhyeon Yoon

Abstract:

Flow coastdown phenomena are very important to secure nuclear fuel integrity during loss of off-site power accidents. In this study, primary coolant flow coastdown phenomena are investigated for the Jordan Research and Training Reactor (JRTR) using a simulation software package, Modular Modelling System (MMS). Two MMS models are built. The first one is a simple model to investigate the characteristics of the primary coolant pump only. The second one is a model for a simulation of the Primary Coolant System (PCS) loop, in which all the detailed design data of the JRTR PCS system are modelled, including the geometrical arrangement data. The same design data for a PCS pump are used for both models. Coastdown curves obtained from the two models are compared to study the PCS loop coolant inertia effect on a flow coastdown. Results showed that the loop coolant inertia effect is found to be small in the JRTR PCS loop, i.e., about one second increases in a coastdown half time required to halve the coolant flow rate. The effects of different flywheel inertia on the flow coastdown are also investigated. It is demonstrated that the coastdown half time increases with the flywheel inertia linearly. The designed coastdown half time is proved to be well above the design requirement for the fuel integrity.

Keywords: flow coastdown, loop inertia, modelling, research reactor

Procedia PDF Downloads 495

Authors: A. H. El-Shazly, A. El-Tayeb, M. F. Elkady, Mona G. E. Ibrahim, Abdelazim M. Negm

Abstract:

In this paper, corona discharge plasma reactor was used for degradation of organic pollution in aqueous solutions in batch reactor. This work examines the possibility of increasing the organic pollution removal efficiency from wastewater using non-thermal plasma. Three types of organic pollution phenol, acid blue 25 and methylene blue are presented to investigate experimentally the amount of organic pollution removal efficiency from wastewater. Measurement results for phenol degradation percentage are 71% in 35 min and 96% when its residence time is 60 min. In addition, the degradation behavior of acid blue 25 utilizing dual pin-to-plate corona discharge plasma system displays a removal efficiency of 82% in 11 min. The complete decolorization was accomplished in 35 min for concentration of acid blue 25 up to 100 ppm. Furthermore, the methylene blue degradation touched up to 85% during 35 min treatment in corona discharge plasma a batch reactor system. The decolorization ratio, conductivity, corona current and discharge energy are considered at various concentration molarity for AlCl3, CaCl2, KCl and NaCl under different molar concentration. It was observed that the attendance of salts at the same concentration level considerably diminished the rate and the extent of decolorization. The research presented that the corona system could be positively utilized in a diversity of organically contaminated at diverse concentrations. Energy consumption requirements for decolorization was considered. The consequences will be valuable for designing the plasma treatment systems appropriate for industrial wastewaters.

Keywords: wastewater treatment, corona discharge, non-thermal plasma, organic pollution

Procedia PDF Downloads 332

Authors: Muhammad Yusuf Abduh, Robert Manurung, Hero Jan Heeres

Abstract:

Biodiesel can be produced in small scale mobile units which are designed with local input and demand. Unlike the typical biodiesel production plants, mobile biodiesel unit consiss of a biodiesel production facility placed inside a standard cargo container and mounted on a truck so that it can be transported to a region near the location of raw materials. In this paper, we review the existing concept and unit for the development of community-scale and mobile production of biodiesel. This includes the main reactor technology to produce biodiesel as well as the pre-treatment prior to the reaction unit. The pre-treatment includes the oil-expeller unit to obtain oil from the oilseeds as well as the quality control of the oil before it enters the reaction unit. This paper also discusses the post-treatment after the production of biodiesel. It includes the refining and purification of biodiesel to meet the product specification set by the biodiesel industry.

Keywords: biodiesel, community scale, mobile biodiesel unit, reactor technology

Procedia PDF Downloads 233

Authors: Binod Shrestha, Sandrine Hoppe, Thierry Ghislain, Phillipe Marchal, Nicolas Brosse, Anthony Dufour

Abstract:

The thermochemical conversion of lignin has received an increasing interest in the frame of different biorefinery concepts for the production of chemicals or energy. It is needed to better understand the physical and chemical conversion of lignin for feeder and reactor designs. In-situ rheology reveals the viscoelastic behaviour of lignin upon thermal conversion. The softening, re-solidification (char formation), swelling and shrinking behaviours are quantified during pyrolysis in real-time [1]. The in-situ rheology of an alkali lignin (Protobind 1000) was conducted in high torque controlled strain rheometer from 35°C to 400°C with a heating rate of 5°C.min-1. The swelling, through glass phase transition overlapped with depolymerization, and solidification (crosslinking and “char” formation) are two main phenomena observed during lignin pyrolysis. The onset of temperatures for softening and solidification for this lignin has been found to be 141°C and 248°C respectively. An ex-situ characterization of lignin/char residues obtained at different temperatures after quenching in the rheometer gives a clear understanding of the pathway of lignin degradation. The lignin residues were sampled from the mid-point temperatures of the softening range and solidification range to study the chemical transformations undergoing. Elemental analysis, FTIR and solid state NMR were conducted after quenching the solid residues (lignin/char). The quenched solid was also extracted by suitable solvent and followed by acetylation and GPC-UV analysis. The combination of 13C NMR and GPC-UV reveals the depolymerization followed by crosslinking of lignin/char. NMR and FTIR provide the evolution of functional moieties upon temperature. Physical and chemical mechanisms occurring during lignin pyrolysis are accounted in this study. Thanks to all these complementary methods.

Keywords: pyrolysis, bio-chemicals, valorization, mechanism, softening, solidification, cross linking, rheology, spectroscopic methods

Procedia PDF Downloads 423

Authors: Khalid S. Hashim, Andy Shaw, Rafid Alkhaddar, David Phipps, Ortoneda Pedrola

Abstract:

Temperature is an essential parameter in the electrocoagulation process (EC) as it governs the solubility of electrodes and the precipitates and the collision rate of particles in water being treated. Although it has been about 100 years since the EC technology was invented and applied in water and wastewater treatment, the effects of temperature on the its performance were insufficiently investigated. Thus, the present project aims to fill this gap by an innovative use of perforated flow columns in the designing of a new EC reactor (ECR1). The new reactor (ECR1) consisted of a Perspex made cylinder container supplied with a flow column consisted of perorated discoid electrodes that made from aluminium. The flow column has been installed vertically, half submerged in the water being treated, inside a plastic cylinder. The unsubmerged part of the flow column works as a radiator for the water being treated. In order to investigate the performance of ECR1; water samples with different initial temperatures (15, 20, 25, 30, and 35 °C) to the ECR1 for 20 min. Temperature of effluent water samples were measured using Hanna meter (Model: HI 98130). The obtained results demonstrated that the ECR1 reduced water temperature from 35, 30, and 25 °C to 24.6, 23.8, and 21.8 °C respectively. While low water temperature, 15 °C, increased slowly to reach 19.1 °C after 15 minutes and kept the same level till the end of the treatment period. At the same time, water sample with initial temperature of 20 °C showed almost a steady level of temperature along the treatment process, where the temperature increased negligibly from 20 to 20.1 °C after 20 minutes of treatment. In conclusion, ECR1 is able to control the temperature of water being treated around the room temperature even when the initial temperature was high (35 °C) or low (15 °C).

Keywords: electrocoagulation, flow column, treatment, water temperature

Procedia PDF Downloads 427

Authors: Md. Nurul Islam Siddique, A. W. Zularisam

Abstract:

The effect of gradual increase in organic loading rate (OLR) and temperature on biomethanation from petrochemical wastewater treatment was investigated using CSTR. The digester performance was measured at hydraulic retention time (HRT) of 4 to 2d, and start up procedure of the reactor was monitored for 60 days via chemical oxygen demand (COD) removal, biogas and methane production. By enhancing the temperature from 30 to 55 ˚C Thermophilic condition was attained, and pH was adjusted at 7 ± 0.5 during the experiment. Supreme COD removal competence was 98±0.5% (r = 0.84) at an OLR of 7.5 g-COD/Ld and 4d HRT. Biogas and methane yield were logged to an extreme of 0.80 L/g-CODremoved d (r = 0.81), 0.60 L/g-CODremoved d (r = 0.83), and mean methane content of biogas was 65.49%. The full acclimatization was established at 55 ˚C with high COD removal efficiency and biogas production. An OLR of 7.5 g-COD/L d and HRT of 4 days were apposite for petrochemical wastewater treatment.

Keywords: anaerobic digestion, petrochemical wastewater, CSTR, methane

Procedia PDF Downloads 351

Authors: Ashiff Khan, A. Seetharaman, Abhijit Dasgupta

Abstract:

The new era of big data (BD) is influencing chemical industries tremendously, providing several opportunities to reshape the way they operate and help them shift towards intelligent manufacturing. Given the availability of free software and the large amount of real-time data generated and stored in process plants, chemical industries are still in the early stages of big data adoption. The industry is just starting to realize the importance of the large amount of data it owns to make the right decisions and support its strategies. This article explores the importance of professional competencies and data science that influence BD in chemical industries to help it move towards intelligent manufacturing fast and reliable. This article utilizes a literature review and identifies potential applications in the chemical industry to move from conventional methods to a data-driven approach. The scope of this document is limited to the adoption of BD in chemical industries and the variables identified in this article. To achieve this objective, government, academia, and industry must work together to overcome all present and future challenges.

Keywords: chemical engineering, big data analytics, industrial revolution, professional competence, data science

Procedia PDF Downloads 81

Authors: Derjew Ayele Ejigu, Houde Song, Xiaojing Liu

Abstract:

This work presents the particle swarm optimization trained neural network (PSO-NN) supervisory proportional integral derivative (PID) control method to monitor the pressurized water reactor (PWR) core power for safe operation. The proposed control approach is implemented on the transfer function of the PWR core, which is computed from the state-space model. The PWR core state-space model is designed from the neutronics, thermal-hydraulics, and reactivity models using perturbation around the equilibrium value. The proposed control approach computes the control rod speed to maneuver the core power to track the reference in a closed-loop scheme. The particle swarm optimization (PSO) algorithm is used to train the neural network (NN) and to tune the PID simultaneously. The controller performance is examined using integral absolute error, integral time absolute error, integral square error, and integral time square error functions, and the stability of the system is analyzed by using the Bode diagram. The simulation results indicated that the controller shows satisfactory performance to control and track the load power effectively and smoothly as compared to the PSO-PID control technique. This study will give benefit to design a supervisory controller for nuclear engineering research fields for control application.

Keywords: machine learning, neural network, pressurized water reactor, supervisory controller

Procedia PDF Downloads 149

Authors: Vivek Kumar, Alexander M. Zaitsev

Abstract:

A study on chemical sensing properties of carbon nanofilms on diamond for developing all-carbon chemical sensors is presented. The films were obtained by high temperature graphitization of diamond followed by successive plasma etchings. Characterization of the films was done by Raman spectroscopy, atomic force microscopy, and electrical measurements. Fast and selective response to common organic vapors as seen as sensitivity of electrical conductance was observed. The phenomenological description of the chemical sensitivity is proposed as a function of the surface and bulk material properties of the films.

Keywords: chemical sensor, carbon nanofilm, graphitization of diamond, plasma etching, Raman spectroscopy, atomic force microscopy

Procedia PDF Downloads 440

Authors: Vijay Sodhi, Charanjit Singh, Neelam Sodhi, Puneet P. S. Cheema, Reena Sharma, Mithilesh K. Jha

Abstract:

The management and secure disposal of the biosludge generated from widely commercialized conventional activated sludge (CAS) treatments become a potential environmental issue. Thus, a sustainable technological upgradation to the CAS for sludge yield minimization has recently been gained serious attention of the scientific community. A number of recently reported studies effectively addressed the remedial technological advancements that in monopoly limited to the municipal wastewater. Moreover, the critical review of the literature signifies side-stream sludge minimization as a complex task to maintain. In this work, therefore, a hybrid moving bed biofilm reactor (MBBR) configuration (named as AMOMOX process) for in-situ minimization of the excess biosludge generated from high organic strength tannery wastewater has been demonstrated. The AMOMOX collectively stands for anoxic MBBR (as AM), aerobic MBBR (OM) and an oxic CAS (OX). The AMOMOX configuration involved a combined arrangement of an anoxic MBBR and oxic MBBR coupled with the aerobic CAS. The AMOMOX system was run in parallel with an identical CAS reactor. Both system configurations were fed with same influent to judge the real-time operational changes. For the AMOMOX process, the strict maintenance of operational strategies resulted about 95% removal of NH4-N and SCOD from tannery wastewater. Here, the nourishment of filamentous microbiota and purposeful promotion of cell-lysis effectively sustained sludge yield (Yobs) lowering upto 0.51 kgVSS/kgCOD. As a result, the volatile sludge scarcity apparent in the AMOMOX system succeeded upto 47% reduction of the excess biosludge. The corroborated was further supported by FE-SEM imaging and thermogravimetric analysis. However, the detection of microbial strains habitat underlying extended SRT (23-26 days) of the AMOMOX system would be the matter of further research.

Keywords: tannery wastewater, moving bed biofilm reactor, sludhe yield, sludge minimization, solids retention time

Procedia PDF Downloads 68

Authors: Gabriela Rivadeneyra-Romero, Claudia del C. Gutierrez Torres, Sergio A. Martinez-Delgadillo, Victor X. Mendoza-Escamilla, Alejandro Alonzo-Garcia

Abstract:

Ultrasonic degradation is currently being used in sonochemical reactors to degrade pollutant compounds from aqueous media, as emerging contaminants (e.g. pharmaceuticals, drugs and personal care products.) because they can produce possible ecological impacts on the environment. For this reason, it is important to develop appropriate water and wastewater treatments able to reduce pollution and increase reuse. Pollutants such as textile dyes, aromatic and phenolic compounds, cholorobenzene, bisphenol-A and carboxylic acid and other organic pollutants, can be removed from wastewaters by sonochemical oxidation. The effect on the removal of pollutants depends on the type of the ultrasonic frequency used; however, not much studies have been done related to the behavior of the fluid into the sonoreactors operated at different ultrasonic frequencies. Based on the above, it is necessary to study the hydrodynamic behavior of the liquid generated by the ultrasonic irradiation to design efficient sonoreactors to reduce treatment times and costs. In this work, it was studied the hydrodynamic behavior of the fluid in sonochemical reactors at different frequencies (250 kHz, 500 kHz and 1000 kHz). The performances of the sonoreactors at those frequencies were simulated using computational fluid dynamics (CFD). Due to there is great sound speed gradient between piezoelectric and fluid, k-e models were used. Piezoelectric was defined as a vibration surface, to evaluate the different frequencies effect on the fluid into sonochemical reactor. Structured hexahedral cells were used to mesh the computational liquid domain, and fine triangular cells were used to mesh the piezoelectric transducers. Unsteady state conditions were used in the solver. Estimation of the dissipation rate, flow field velocities, Reynolds stress and turbulent quantities were evaluated by CFD and 2D-PIV measurements. Test results show that there is no necessary correlation between an increase of the ultrasonic frequency and the pollutant degradation, moreover, the reactor geometry and power density are important factors that should be considered in the sonochemical reactor design.

Keywords: CFD, reactor, ultrasound, wastewater

Procedia PDF Downloads 186

Authors: Heather Wyman-Pain, Yuankai Bian, Furong Li

Abstract:

The decreasing use of fossil fuel power stations has a negative effect on the stability of the electricity systems in many countries. Nuclear power stations have traditionally provided minimal ancillary services to support the system but this must change in the future as they replace fossil fuel generators. This paper explains the development of the four most popular reactor types still in regular operation across the world which have formed the basis for most reactor development since their commercialisation in the 1950s. The use of nuclear power in four countries with varying levels of capacity provided by nuclear generators is investigated, using the primary frequency response provided by generators as a measure for the electricity networks stability, to assess the need for nuclear generators to provide additional support as their share of the generation capacity increases.

Keywords: frequency control, nuclear power generation, power system stability, system inertia

Procedia PDF Downloads 435

Authors: C. Müller, T. Ortmann, S. Scholl, H. J. Jördening

Abstract:

Multienzymatic catalysis can be used as an alternative to chemical synthesis or hydrolysis of polysaccharides for the production of high value oligosaccharides from cheap resources such as sucrose. However, development of multienzymatic processes is complex, especially with respect to suitable conditions for enzymes originating from different organisms. Furthermore, an optimal configuration of the catalysts in a reaction cascade has to be found. These challenges can be approached by design of experiments. The system investigated in this study is a trienzymatic catalyzed reaction which results in laminaribiose production from sucrose and comprises covalently immobilized sucrose phosphorylase (SP), glucose isomerase (GI) and laminaribiose phosphorylase (LP). Operational windows determined with design of experiments and kinetic data of the enzymes were used to optimize the enzyme ratio for maximum product formation and minimal production of byproducts. After adjustment of the enzyme activity ratio to 1: 1.74: 2.23 (SP: LP: GI), different process options were investigated in silico. The considered options included substrate dependency, the use of glucose as co-substrate and substitution of glucose isomerase by glucose addition. Modeling of batch operation in a stirred tank reactor led to yields of 44.4% whereas operation in a continuous stirred tank reactor resulted in product yields of 22.5%. The maximum yield in a bienzymatic system comprised of sucrose phosphorylase and laminaribiose phosphorylase was 67.7% with sucrose and different amounts of glucose as substrate. The experimental data was in good compliance with the process model for batch operation. The continuous operation will be investigated in further studies. Simulation of operational process possibilities enabled us to compare various operational modes regarding different aspects such as cost efficiency, with the minimum amount of expensive and time-consuming practical experiments. This gives us more flexibility in process implementation and allows us, for example, to change the production goal from laminaribiose to higher oligosaccharides.

Keywords: design of experiments, enzyme kinetics, multi-enzymatic system, in silico process development

Procedia PDF Downloads 332

Authors: H. Yousefnia, N. Amraee, M. Hosntalab, S. Zolghadri, A. Bahrami-Samani

Abstract:

The aim of this study was the preparation of a new agent for bone marrow ablation in patients with multiple myeloma. 166Ho was produced at Tehran research reactor via 165Ho(n,γ)166Ho reaction. Complexion of Ho‐166 with BPAMD was carried out by the addition of about 200µg of BPAMD in absolute water to 1 mci of 166HoCl3 and warming up the mixture 90 0C for 1 h. 166Ho-BPAMD was prepared successfully with radio chemical purity of 95% which was measured by ITLC method. The final solution was injected to wild-type mice and bio distribution was determined up to 48 h. SPECT images were acquired after 2 and 48 h post injection. Both the bio distribution studies and SPECT imaging indicated high bone uptake, while accumulation in other organs was approximately negligible. The results show that 166Ho-BPAMD has suitable characteristics and can be used as a new bone marrow ablative agent.

Keywords: bone marrow ablation, BPAMD, 166Ho, SPECT

Procedia PDF Downloads 502

Authors: Doo Ki Lee, Kumaresh Selvakumar, Man Young Kim, In Jae Song

Abstract:

The widespread utilization of mixer in selective catalytic reduction (SCR) system marks a remarkable advantage in diesel engines. In the automotive selective catalytic reduction (SCR) system, the de-NOX efficiency can be improved by highly uniform flow with effective turbulent mixing. In this paper, the exhaust pipe is complemented with the swirling mixers of three different vane angles installed at the upstream of the SCR reactor. The attributes of the mixer are established by the variation in flow behavior followed by the drawback owing to the absence of mixer. In particular, the information pertaining to the selection of proper static mixer is provided based on the correlation between the uniformity index (UI) and the pressure drop. The uniform distribution of the flow at the entrance of the SCR reactor aids to determine the configuration which gives high mixing performance and comprehend the function of the mixer.

Keywords: pressure drop, selective catalytic reduction, static mixer, turbulent mixing, uniformity index

Procedia PDF Downloads 932

Authors: Khalid S. Hashim, Andy Shaw, Rafid Alkhaddar

Abstract:

Dissolved oxygen (DO) plays a key role in the electrocoagulation process (EC) as it oxidizes the heavy metals, ammonia, and cyanide into other forms that can be removed easily from water. Hence, many of the previous investigations used external aerators to provide the required DO inside EC reactors, especially when the water being treated had a low DO (such as leachate and high organic content waters), or when the DO depleted during the EC treatment. Although the external aeration process effectively enhances the DO concentration, it has a significant impact on energy consumption. Thus, the present project aims to fill a part of this gap in the literature by an innovative use of perforated flow columns in the design of an EC reactor (ECR1). In order to investigate the performance of ECR1, water samples with a controlled DO concentration were pumped at different flow rates (110, 220, and 440 ml/min) to the ECR1 for 10 min. The obtained results demonstrated that the ECR1 increased the DO concentration from 5.0 to 9.54, 10.53, and 11.0 mg/L, which is equivalent to 90.8%, 110.6%, and 120% at flow rates of 110, 220, and 440 mL/min respectively.

Keywords: flow column, electrocoagulation, dissolved oxygen, water treatment

Procedia PDF Downloads 338

Authors: Dalila Chouder, Djaafer Benachour

Abstract:

This work concerns the study of the adsorption of metal ions Ag +, Mg +, and Ni2+ in aqueous medium by polydibenzoether-ROWN based on three factors: Temperature, time and concentration. The polydibenzoether crown was synthesized by two means: Chemical and electrochemical. The behavior of the two polymers has been different, and turns out very interesting for chemical polydibenzoether crown has identified conditions. Chemical and électronique polydibenzoether crown have different extraction screw vi property of adsoption of ions fifférents, this study also shows that plyméres doped may have an advantageous electrical conductivity.

Keywords: polymerization, electrochemical, conductivity, complexing metal ions

Procedia PDF Downloads 262

Authors: Grzegorz Raniszewski, Zbigniew Kolacinski, Lukasz Szymanski, Slawomir Wiak, Lukasz Pietrzak, Dariusz Koza

Abstract:

One of the most promising area for carbon nanotubes (CNTs) application is medicine. One of the most devastating diseases is cancer. Carbon nanotubes may be used as carriers of a slowly released drug. It is possible to use of electromagnetic waves to destroy cancer cells by the carbon nanotubes (CNTs). In our research we focused on thermal ablation by ferromagnetic carbon nanotubes (Fe-CNTs). In the cancer cell hyperthermia functionalized carbon nanotubes are exposed to radio frequency electromagnetic field. Properly functionalized Fe-CNTs join the cancer cells. Heat generated in nanoparticles connected to nanotubes warm up nanotubes and then the target tissue. When the temperature in tumor tissue exceeds 316 K the necrosis of cancer cells may be observed. Several techniques can be used for Fe-CNTs synthesis. In our work, we use high-temperature methods where arc-discharge is applied. Low-temperature systems are microwave plasma with assisted chemical vapor deposition (MPCVD) and hybrid physical-chemical vapor deposition (HPCVD). In the arc discharge system, the plasma reactor works with a pressure of He up to 0,5 atm. The electric arc burns between two graphite rods. Vapors of carbon move from the anode, through a short arc column and forms CNTs which can be collected either from the reactor walls or cathode deposit. This method is suitable for the production of multi-wall and single-wall CNTs. A disadvantage of high-temperature methods is a low purification, short length, random size and multi-directional distribution. In MPCVD system plasma is generated in waveguide connected to the microwave generator. Then containing carbon and ferromagnetic elements plasma flux go to the quartz tube. The additional resistance heating can be applied to increase the reaction effectiveness and efficiency. CNTs nucleation occurs on the quartz tube walls. It is also possible to use substrates to improve carbon nanotubes growth. HPCVD system involves both chemical decomposition of carbon containing gases and vaporization of a solid or liquid source of catalyst. In this system, a tube furnace is applied. A mixture of working and carbon-containing gases go through the quartz tube placed inside the furnace. As a catalyst ferrocene vapors can be used. Fe-CNTs may be collected then either from the quartz tube walls or on the substrates. Low-temperature methods are characterized by higher purity product. Moreover, carbon nanotubes from tested CVD systems were partially filled with the iron. Regardless of the method of Fe-CNTs synthesis the final product always needs to be purified for applications in medicine. The simplest method of purification is an oxidation of the amorphous carbon. Carbon nanotubes dedicated for cancer cell thermal ablation need to be additionally treated by acids for defects amplification on the CNTs surface what facilitates biofunctionalization. Application of ferromagnetic nanotubes for cancer treatment is a promising method of fighting with cancer for the next decade. Acknowledgment: The research work has been financed from the budget of science as a research project No. PBS2/A5/31/2013

Keywords: arc discharge, cancer, carbon nanotubes, CVD, thermal ablation

Procedia PDF Downloads 445

Authors: Ankita Jadon, Sidi Souvi, Nathalie Girault, Denis Petitprez

Abstract:

Safety requirements for Generation IV nuclear reactor designs, especially the new generation sodium-cooled fast reactors (SFR) require a risk-informed approach to model severe accidents (SA) and their consequences in case of outside release. In SFRs, aerosols are produced during a core disruptive accident when primary system sodium is ejected into the containment and burn in contact with the air; producing sodium aerosols. One of the key aspects of safety evaluation is the in-containment sodium aerosol behavior and their interaction with fission products. The study of the effects of sodium fires is essential for safety evaluation as the fire can both thermally damage the containment vessel and cause an overpressurization risk. Besides, during the fire, airborne fission product first dissolved in the primary sodium can be aerosolized or, as it can be the case for fission products, released under the gaseous form. The objective of this work is to study the interactions between sodium aerosols and fission products (Iodine, toxic and volatile, being the primary concern). Sodium fires resulting from an SA would produce aerosols consisting of sodium peroxides, hydroxides, carbonates, and bicarbonates. In addition to being toxic (in oxide form), this aerosol will then become radioactive. If such aerosols are leaked into the environment, they can pose a danger to the ecosystem. Depending on the chemical affinity of these chemical forms with fission products, the radiological consequences of an SA leading to containment leak tightness loss will also be affected. This work is split into two phases. Firstly, a method to theoretically understand the kinetics and thermodynamics of the heterogeneous reaction between sodium aerosols and fission products: I2 and HI are proposed. Ab-initio, density functional theory (DFT) calculations using Vienna ab-initio simulation package are carried out to develop an understanding of the surfaces of sodium carbonate (Na2CO3) aerosols and hence provide insight on its affinity towards iodine species. A comprehensive study of I2 and HI adsorption, as well as bicarbonate formation on the calculated lowest energy surface of Na2CO3, was performed which provided adsorption energies and description of the optimized configuration of adsorbate on the stable surface. Secondly, the heterogeneous reaction between (I2)g and Na2CO3 aerosols were investigated experimentally. To study this, (I2)g was generated by heating a permeation tube containing solid I2, and, passing it through a reaction chamber containing Na2CO3 aerosol deposit. The concentration of iodine was then measured at the exit of the reaction chamber. Preliminary observations indicate that there is an effective uptake of (I2)g on Na2CO3 surface, as suggested by our theoretical chemistry calculations. This work is the first step in addressing the gaps in knowledge of in-containment and atmospheric source term which are essential aspects of safety evaluation of SFR SA. In particular, this study is aimed to determine and characterize the radiological and chemical source term. These results will then provide useful insights for the developments of new models to be implemented in integrated computer simulation tool to analyze and evaluate SFR safety designs.

Keywords: iodine adsorption, sodium aerosols, sodium cooled reactor, DFT calculations, sodium carbonate

Procedia PDF Downloads 214

Authors: Vijayakumar Karunamoothei, Stephen Wylie, Andy Shaw, Al Shamma'A Ahmed

Abstract:

The main aim of this research is to investigate, analyse and provide solutions for the reduction of food waste in the restaurant industry. The amount of food waste that is sent to landfill by UK restaurants and food chains is considerably high, and also acts as an additional cost to the restaurants, as well as being a significant environmental issue. Food waste, for the most part, is disposed in landfill, but due to rising costs associated with waste disposal, it increases public concerns about the environmental issue. This makes conversion of food waste to energy an economic solution. The relevant properties, such as water content and calorific value, will vary considerably, depending on the particular type of food. This work, therefore, includes the collection and analysis of real data from restaurants on weekly basis. It will also investigate how the waste destined for landfill can be instead reused to produce fuels such as syngas or ethanol, or alternatively as fertilizer. The potential for syngas production will be tested using a microwave plasma reactor.

Keywords: fertilizer, microwave, plasma reactor, syngas

Procedia PDF Downloads 355

Authors: Vanessa R. Ralph, Leah J. Scharlott, Megan Y. Deshaye, Ryan L. Stowe

Abstract:

Given the traditions of chemistry teaching, one may not question whether chemical phenomena play a prominent role. Yet, the role of chemical phenomena in an introductory chemistry course may define the extent to which the course is introductory, chemistry, and equitable. Picture, for example, the classic Ideal Gas Law problem. If one envisions a prompt wherein students are tasked with calculating a missing variable, then one envisions a prompt that relies on chemical phenomena as a context rather than as a model to understand the natural world. Consider a prompt wherein students are tasked with applying molecular models of gases to explain why the vapor pressure of a gaseous solution of water differs from that of carbon dioxide. Here, the chemical phenomenon is not only the context but also the subject of the prompt. Deliveries of general and organic chemistry were identified as ranging wildly in the integration of chemical phenomena. The more incorporated the phenomena, the more equitable the assessment task was for students of varying access to pre-college math and science preparation. How chemical phenomena are integrated may very well define whether courses are chemistry, are introductory, and are equitable. Educators of chemistry are invited colleagues to discuss the role of chemical phenomena in their courses and consider the long-lasting impacts of replicating tradition for tradition’s sake.

Keywords: equitable educational practices, chemistry curriculum, content organization, assessment design

Procedia PDF Downloads 194

Authors: Marcin Dębowski, Marcin Zieliński, Mirosław Krzemieniewski

Abstract:

This publication presents a reactor designed for methane fermentation of organic substrates. The design is based on rotating cellular cylinders connected to a biomass feeder and an ultrasonic generator. This allows for simultaneous mixing and partial disintegration of the biomass, as well as stimulating higher metabolic rates within the microorganisms. Such a design allows from 2-fold to 14-fold reduction of power usage when compared to conventional mixing systems. The sludge does not undergo mechanical deformation during the mixing process, which improves substrate biodegradation efficiency by 10-15%. Cavitation occurs near the surface of the rods, partially releasing the biomass and separating it from the destroyed microorganisms. Biogas is released further away from the cellular cylinder rods due to the effect of the ultrasonic waves, in addition to increased biochemical activity of the microorganisms and increased exchange of the nutrient medium with metabolic products, which results in biogas production increase by about 15%.

Keywords: methane fermentation, bioreactors, biomass, mixing system

Procedia PDF Downloads 524