Multiple Reactors Research Articles

Using Flow Electrodes in Multiple Reactors in Series for Continuous Energy Generation from Capacitive Mixing

Efficient conversion of “mixing energy” to electricity through capacitive mixing (CapMix) has been limited by low energy recoveries, low power densities, and noncontinuous energy production resulting from intermittent charging and discharging cycles. We show here that a CapMix system based on a four-reactor process with flow electrodes can generate constant and continuous energy, providing a more flexible platform for harvesting mixing energy. The power densities were dependent on the flow-electrode carbon loading, with 5.8 ± 0.2 mW m–2 continuously produced in the charging reactor and 3.3 ± 0.4 mW m–2 produced in the discharging reactor (9.2 ± 0.6 mW m–2 for the whole system) when the flow-electrode carbon loading was 15%. Additionally, when the flow-electrode electrolyte ion concentration increased from 10 to 20 g L–1, the total power density of the whole system (charging and discharging) increased to 50.9 ± 2.5 mW m–2.

Breaking the mainstream mold: The birth of a local political cartoonist in post-3.11 Japan

This paper introduces the Disaster Picture-Diary political cartoons of Asakura Yūzō which appear in the Japanese regional newspaper Fukushima Minpō. After the so-called 3.11 disaster’s triple blow of earthquake, tsunami, and multiple nuclear reactor meltdowns in 2011, intense public and media interest and debates erupted over: how to help the victims; how to rebuild; what to do about the ongoing nuclear problem; and what should be the future of direction the nation. Yet, cartoonists in national daily newspapers failed to get involved in much of this debate. They basically continued on as they had done before the disaster merely lightly mocking politicians, their eyes closed to wider problems. In contrast, Asakura’s cartoons which began in the wake of 3.11 in the disaster affected region, broke away from this mainstream form of cartoon discourse to comment on a much greater variety of post-3.11 issues using a much more diverse range of drawing styles. In this sense, though still seemingly restrained to an outside observer from a country with a more aggressive satirical cartooning, for Asakura it is definitely a case of “anything goes”. This paper gives an overview of the disaster, and mainstream political cartooning before and after 3.11. It then introduces examples of Asakura’s Disaster Picture-Diary political cartoons, contrasting them with mainstream national cartoons to underscore how his work differs. In concluding, a number of reasons for these differences are provisionally forwarded.

Thermodynamic analysis of Glycerol Steam Reforming for hydrogen production with in situ hydrogen and carbon dioxide separation

A thermodynamic study of Glycerol Steam Reforming (GSR) for hydrogen production with in situ carbon dioxide and hydrogen (reaction products) simultaneous removal was performed. The sorption-enhanced membrane reactor (SEMR) was divided into multiple sub-Gibbs reactors and the Gibbs free energy minimization method was employed. The effects of temperature (600–800 K), molar water-to-glycerol feed ratio (WGFR) (3–9), pressure (1–5 atm) and fraction of hydrogen and carbon dioxide removal (f, 0–0.99) on the GSR process were target of investigation. A hydrogen yield (total moles of hydrogen produced/mole of reacted glycerol) very close to the stoichiometric value of 7 was obtained at 700 K, WGFR of 9, 1 atm and for fCO2=0.99 and fH2=0.80. This corresponds to an enhancement of 217%, 47% and 22% in terms of hydrogen yield comparatively to the traditional reactor (TR), sorption-enhanced reactor (SER) with carbon dioxide capture (fCO2=0.99) and membrane reactor (MR) with hydrogen separation (fH2=0.80), respectively. In terms of coke, its formation was only observed under WGFRs below the stoichiometric value of 3.

New design and mapping of sonochemical reactor operating at capacity of 72L

Abstract Understanding of the distribution of cavitational activity helps in achieving efficient design and scale up of sonochemical reactors. The experimental investigation of the mapping of cavitational activity has been performed in the present work in a large scale sonochemical reactor operating at 40 kHz with a capacity of 72 L. The reactor is a multiple transducer rectangular flow cell type reactor operating at variable power dissipation levels with maximum rating of 2400 W. Two chemical dosimeters have been used for the mapping studies as potassium iodide and dichlorvos degradation for the quantification of cavitational activity. The calorimetric power measurement has also been performed to quantify the actual power dissipation in the liquid medium. Effect of input power on the cavitational activity has been investigated at different locations in the ultrasonic flow cell. The obtained results have established that there is good agreement between the two chemical dosimeters. Also the cavitational activity distribution was fairly uniform as compared to other conventional designs based on the use of single transducer. It has been also confirmed that the novel method based on dichlorvos degradation adapted in the present work can be used as one of the mapping techniques to establish better correspondence with the wastewater treatment applications due to similarity in the controlling mechanisms. Overall, the new design presented in the work gives uniform distribution of the cavitational activity to a greater extent and can be a useful design for commercial scale installations.

Width-dependent interaction of trench-like microdischarges arranged in sub-arrays on a single silicon-based chip

Multiple trench microdischarge reactor arrays based on a silicon (Si) platform were investigated as a concept to overcome production-based errors. The devices incorporated four sub-arrays of trench-like anisotropically etched cavities on a single 2 cm × 2 cm Si chip. Each sub-array consisted of an equal number of structures of equal length, depth and separation only varying in trench width. Experiments were performed in argon (Ar) close to atmospheric pressure at ac frequencies of the order of 10 kHz. The arrays were characterized by means of electrical measurements and by (phase-resolved) optical emission. It is shown that the whole device as well as the independent sub-arrays and the individual cavities behave in a similar way as the inverted-pyramid structures investigated beforehand. Under identical conditions, the voltage required for a first ignition increases with the width of the cavities. For maximum voltages high enough for operation of all sub-arrays, the individual arrays ignite within the excitation period in reverse order. For different excitation frequencies, self-pulsing and emission waves propagating independently across the sub-arrays were observed. Both phenomena show distinct characteristics for the individual sub-arrays being more prominent for the smaller cavities. The observations are interpreted within the frame of a simple physical picture, as a field and a surface-dependent process and the influence of long-living species such as metastables.

Electrochemical treatment of tannery effluent using a battery integrated DC-DC converter and solar PV power supply—An approach towards environment and energy management

Electrochemical oxidation of tannery effluent was carried out in batch, batch recirculation and continuous reactor configurations under different conditions using a battery-integrated DC-DC converter and solar PV power supply. The effect of current density, electrolysis time and fluid flow rate on chemical oxygen demand (COD) removal and energy consumption has been evaluated. The results of batch reactor show that a COD reduction of 80.85% to 96.67% could be obtained. The results showed that after 7 h of operation at a current density of 2.5 A dm−2 and flow rate of 100 L h−1 in batch recirculation reactor, the removal of COD is 82.14% and the specific energy consumption was found to be 5.871 kWh (kg COD)−1 for tannery effluent. In addition, the performance of single pass flow reactors (single and multiple reactors) system of various configurations are analyzed.

Terrain and building effects on the transport of radioactive material at a nuclear site

This study identified the terrain and building effects on the atmospheric dispersion of radioactive materials at the Wolsong Nuclear Site. To analyze the atmospheric dispersion of radioactive materials, the AERMOD-PRIME model, CFD model and meteorological data from 2010 were used. The terrain and building effects on the atmospheric dispersion of radioactive materials within a 1km radius of the site were statistically significant. The maximum concentration of the radioactive material increased by 7 times compared to the concentration when the terrain and building effects were not considered. It was found that the terrain and building influenced the decrease in the concentration of radioactive material in a concentric circle with a 914m radius from the center of the site. The concentration of radioactive material in a concentric circle with a 350m radius was two-times higher than the concentration estimated at the backside of the building, which is the downwind side, without any consideration of the terrain and building effects. In consideration of the Korean situation, in which multiple nuclear reactors are built on the same nuclear site, it is necessary to evaluate the risk that may affect workers and nearby residents by reflecting the terrain and building effects.

Reference set selection with generalized orthogonal Procrustes analysis for multivariate statistical process monitoring of multiple production processes

Multivariate process monitoring is important in industry to ensure that production processes perform as close as possible to optimal operation. However, the selection of a reference set of optimal or expected performance is required for efficient process monitoring in real time. In this paper we present the method of generalized orthogonal Procrustes analysis to select a reference set for the multivariate monitoring of multiple production processes simultaneously. We combine generalized orthogonal Procrustes analysis with principal component analysis (PCA) and biplots to illustrate the implementation of the method and the interpretation of the results which provide important information on the relationships between many process variables and differences between the production processes. The work is motivated by an industrial problem involving the multivariate monitoring of a coal gasification production facility considering many process variables monitored across multiple reactors.

B211 多並列SMR型金属燃料高速増殖炉動力プラント(OS3 軽水炉・新型炉・原子力安全(4))

To supply enough nuclear fuel (Pu(plutonium)& <233>^U) in near future, this paper proposes Multiple Small Modular Reactors(SMRs) Power Plant of fast metal breeder. This Power Plant has many (example 36) SMRs, one SMR is equal to one fuel assembly of conventional FBR. This Power Plant always can keep full load without stop with spare SMR, and on the other hand individual SMR can be operated suitably as batch breeding process. The SMR has no fuel exchange equipment is so simple to fill in the core with metal fuel pins densely, and the heavy metal density, <238>^U/Pu ratio, and threshold fission reaction of <238>^U in the core are increased to double, ,finally overall fission fuel breeding productivity is improved radical.

Multiple Nonsteroidal Anti-Inflammatory Drug-Induced Cutaneous Disease: What Differentiates Patients with and without Underlying Chronic Spontaneous Urticaria?

Background: Multiple nonsteroidal anti-inflammatory drug (NSAID) cutaneous reactors may be otherwise normal or have underlying chronic spontaneous urticaria (CSU). This study compared these two phenotypes of NSAID-hypersensitive subjects. Methods: A total of 97 multiple NSAID reactors underwent oral challenges with paracetamol, etoricoxib and tramadol. Atopic status was investigated in all patients, and autoreactivity was ascertained in some cases as well. Otherwise normal multiple NSAID reactors were reevaluated after 1-5 years in order to detect their proneness to CSU. Results: At the first visit, 41 patients had CSU and 56 had multiple NSAID intolerance without any underlying cutaneous disease. Altogether, 22, 10 and 6% of patients did not tolerate paracetamol, etoricoxib and tramadol, respectively, on oral challenge. Intolerance to these alternative drugs showed a strong association (p < 0.01 with all combinations). The two subgroups of patients did not show any difference in terms of mean age, gender distribution, prevalence of atopic diseases, prevalence of single offending NSAIDs and prevalence of intolerance to paracetamol, etoricoxib or tramadol on oral challenge. In all, 20% of multiple NSAID reactors without CSU at presentation developed CSU between 6 months and 5 years after the initial clinical evaluation. Conclusions: Multiple NSAID cutaneous reactors with or without CSU seem identical from a clinical point of view, and some of the latter group show a propensity to acquire the former phenotype over time. A subset of patients apparently identical to the general population of multiple NSAID reactors also react to drugs exerting little or no cyclooxygenase-1 enzyme inhibition and might represent a distinct phenotype of NSAID-hypersensitive patients possibly characterized by a different underlying pathogenesis.

Simultaneous design of the optimal reaction and process concept for multiphase systems

In complex chemical processes optimizing the reactor with respect to a stand-alone reactor performance criterium such as product selectivity does not necessarily yield the best process-wide reaction concept. Especially in case of multiphase reaction systems, which often involve complex reaction networks, nonideal phase behavior and multiple recycles, reactor and process have to be optimized simultaneously since the reactor affects the separation units and vice versa. In order to derive the process-wide optimal reaction concept in combination with optimal process parameters, a systematic optimization procedure based on a large scale optimization problem constrained by a system of differential algebraic equations (DAE) is presented. The optimization problem contains a detailed model of the reaction section, a process model describing the other units of the process, and models for operational and fixed costs. The solution of the optimization is a set of process parameters and optimal profiles of heat and material fluxes over the reaction coordinate which minimize the production costs. The method is exemplified on the rhodium catalyzed hydroformylation of 1-dodecene in a thermomorphic solvent system.

Ultrasound-assisted extraction of clove buds using batch- and flow-reactors: A comparative study on a pilot scale

Abstract This study will assess the efficiency of both batch and flow ultrasonic reactors (20 L in 45 min) in carrying out the ultrasound-assisted extraction of dry clove buds and compare these more recent methods with classic maceration. Flow ultrasound-assisted extraction was carried out in a new multi-horn reactor working in continuous flow mode (450, 900, 1350 mL/min) and at high power density (about 700 W/L vs 18 W/L in batch). The specific energy input was a slightly lower in flow procedure 47.2 kJ/L vs 48.6 kJ/L in batch reactor. Total phenolic compound content ranged from 191 ± 1 to 215 ± 3 mg gallic acid equivalents/L of extract. The best results were obtained under flow ultrasound-assisted extraction operating at 1350 mL/min (highest phenolic content and best radical scavenging activity). Clove bud volatiles from hydroalcoholic extracts were separated and identified using hyphenated headspace gas chromatography and mass spectrometry. We herein show that the development of large-scale multiple transducer flow reactors operating at high power density allows noteworthy process intensification. Industrial relevance This piece of work was carried out thanks to the investment of Pernod-Richard Italia, an international company worldwide known in the field of liqueurs and wines. Considering the huge amount of plant extracts required by this type of production, only flow systems may be suitable for scaling up. The results of this investigation on pilot reactors pave the road for the set up of an industrial plant.

Optimization of a Multiple Impinging Jets Cavitation Reactor Using Zero‐Valent Iron Powder as Catalyst

AbstractThe effect of a combination of impinging jets and hydrodynamic cavitation technology was investigated by a multiple impinging jets cavitation reactor (MIJCR). Zero‐valent iron (ZVI) powder and rhodamine B were chosen as heterogeneous catalyst and model pollutant, respectively. ZVI addition resulted in more than five times higher decolorization efficiency compared to runs without ZVI. In situ generation of Fenton reagents suggested an advanced Fenton process to explain the enhancing effect of the applied catalyst. Impinging jets and aeration led to significant enhancement of the process, and optimum values of inter‐nozzle distance and initial catalyst concentration favored the decolorization of rhodamine B.

Iron-based syngas chemical looping process and coal-direct chemical looping process development at Ohio State University

The increasing demands for energy and concern of global warming are intertwined issues of critical importance. With the pressing need for clean, efficient, and cost-effective energy conversion processes, the chemical looping strategy has evolved as a promising alternative to the traditional carbonaceous fuel conversion processes. Chemical looping processes utilize oxygen carrier particles to indirectly convert carbonaceous fuels while capturing CO2 for sequestration and/or utilization. Throughout its development, multiple oxygen carrier compositions and reactor configurations have been studied and demonstrated. The Ohio State University (OSU) chemical looping technologies have received significant attention over the recent years. OSU’s unique moving-bed chemical looping technologies coupled with iron-based oxygen carrier particles capable of sustaining hundreds of redox cycles have the advantage of converting a variety of carbonaceous fuels, such as natural gas, coal and biomass, to electricity, H2, liquid fuels, or any combination thereof with zero to negative net CO2 emissions. Specifically, two chemical looping processes are being developed and studied, the syngas chemical looping (SCL) and the coal direct chemical looping (CDCL) technologies. Over the past 14years, these processes have developed from a novel concept to successful sub-pilot (25kWth) demonstrations. With the support of the Advanced Research Projects Agency – Energy (ARPA-E) of the US Department of Energy (USDOE), a 250kWth high pressure SCL pilot scale demonstration project was initiated for processing syngas to cogenerate pure H2 and sequestration-ready CO2 from a Kellogg Brown & Root gasifier at the National Carbon Capture Center. A 25kWth CDCL sub-pilot plant has been constructed and demonstrated at OSU with the support from National Energy Technology Laboratory (NETL) of the United States Department of Energy (USDOE). The combined SCL and CDCL operational time at reactive conditions well exceeds 850h. Multiple aspects of the OSU chemical looping development including the oxygen carrier properties, reaction mechanism studies, reactor design and modeling studies, the bench and sub-pilot scale process testing results, energy integration optimization, and techno-economic analyzes are discussed.

Polymer electrolyte membrane fuel cell grade hydrogen production by methanol steam reforming: A comparative multiple reactor modeling study

Analysis of a fuel processor based on methanol steam reforming has been carried out to produce fuel cell grade H2. Six reactor configurations namely FBR1 (fixed bed reactor), MR1 (H2 selective membrane reactor with one reaction tube), MR2 (H2 selective membrane reactor with two reaction tubes), FBR2 (FBR1+preferential CO oxidation (PROX) reactor), MR3 (MR1+PROX), and MR4 (MR2+PROX) are evaluated by simulation to identify the suitable processing scheme. The yield of H2 is significantly affected by H2 selective membrane, residence time, temperature, and pressure conditions at complete methanol conversion. The enhancement in residence time in MR2 by using two identical reaction tubes provides H2 yield of 2.96 with 91.25mol% recovery at steam/methanol ratio of 1.5, pressure of 2bar and 560K temperature. The exit retentate gases from MR2 are further treated in PROX reactor of MR4 to reduce CO concentration to 4.1ppm to ensure the safe discharge to the environment. The risk of carbon deposition on reforming catalyst is highly reduced in MR4, and MR4 reactor configuration generates 7.4NLmin−1 of CO free H2 from 0.12molmin−1 of methanol which can provide 470W PEMFC feedstock requirement. Hence, process scheme in MR4 provides a compact and innovative fuel cell grade H2 generating unit.

Before and after disaster strikes: A relief supply chain decision support framework

The potential and scope of damages resulting from large scale natural disasters is undisputed. Additionally, the risks that societies are facing continue to grow along with the global population. A decision support risk assessment and mitigation framework for disaster relief supply chain is proposed. This framework was applied to the example of the March 2011 disaster in Japan which was the result of a Tsunami, after a strong earthquake, followed by flooding and meltdown of multiple nuclear reactors. The evidence of relief supply chain effectiveness is examined and diagnosed in specific instances when the supply chain has failed to perform. Key stages are identified within the relief supply chain, and these stages are connected through communication and collaboration. By identifying and quantifying different risks under different stages in the supply chain using fault tree analysis and then imputing them into the model, the results are helpful in the decision making process. The failure mode effects and critical analysis method was used to assess the reliability of a relief supply chain system and its critical components. The research suggests the support for a network authority for utilizing diverse expertise for organizing the efficient relief supply chain. This structure makes use of the community relationships and trust that NGOs have built in areas throughout the world to aid in crises. The development of a robust communications plan and system will help coordination of all groups, prior to, during, and after a disaster, and will provide a more effective response.

Intensification principle of a new three-phase catalytic slurry reactor. Part I: Performance characterisation

This paper presents the concept and the performances of a mini horizontal stirred tank reactor, used for hydrogenation reaction. A simple analytical model based on characteristic times of heat and mass transfer illustrates the intensification principle and shows that the relevant intensification parameter is the mass to heat transfer characteristics times ratio. The proof of concept is made through a small scale reactor named RAPTOR® (French acronym for Reactor with Polyvalent Rectilinear Stirred Reactor with Optimised Transfer). The mass transfer performances are measured and compared to conventional stirred tank reactor and other multiple impeller continuous reactors. In a following second paper, a comparative study is proposed to evaluate the eco-efficiency and the techno-economic advantages of a continuous process involving a RAPTOR® versus a classical batch process based on a stirred reactor.

3D-printed devices for continuous-flow organic chemistry

We present a study in which the versatility of 3D-printing is combined with the processing advantages of flow chemistry for the synthesis of organic compounds. Robust and inexpensive 3D-printed reactionware devices are easily connected using standard fittings resulting in complex, custom-made flow systems, including multiple reactors in a series with in-line, real-time analysis using an ATR-IR flow cell. As a proof of concept, we utilized two types of organic reactions, imine syntheses and imine reductions, to show how different reactor configurations and substrates give different products.

Dietary nucleotides and yeast extract affect the composition and metabolic activities of the swine gut microbiota in a new in vitro fermentation model

Nucleotides (NT) are important compounds to many biological processes but data on the exact role of NT on the gut microbiota remain unclear. In this work we investigated the effects of dietary NT in a medium formulated to simulate the pig ileal chyme on gut microbiota composition and activity using a novel continuous in vitro intestinal fermentation models mimicking the proximal colon. Pig fecal microbiota was immobilized in gellan‐xanthan beads and used as a continuous inoculum in a novel intestinal model platform, operated with multiple parallel reactors to compare treatments on the exact same microbiota composition. Daily effluent samples were collected and analyzed to investigate the composition (qPCR, pyrosequencing) and metabolic activities (HPLC) of the microbiota.We measured significant shifts of microbial diversity, microbiota composition, and activity of effluent samples induced by dietary NT and YE treatments. In particular Lactobacilli (+1.4 Log10) and propionate concentration (+18.7 %) significantly increased in 7.5 g/l high NTYE compare to the control medium. Our data suggest beneficial effects of dietary NT in YE on pig gut microbial balance, associated with enhanced propionate production which could reinforce the barrier effect of the gut microbiota and increased populations of beneficial microbes.This study was supported by a grant from the Worldwide Research Alltech, Inc. in USA.Grant Funding Source: Nutrition (ASN): ASN Graduate Student Research Award Competition, supported by the Nutritional Sciences Council

Multistep organic synthesis using flow chemistry

The technology enabling synthetic chemistry within flow systems has been advanced through remarkable synthetic designs using multistep sequences to conduct synthetic schemes leading to products of high complexity. Continuous flow reactors provide a synthetic platform for the combination of several chemical transformations as a single process. This synthetic strategy enables the chemist to organize multiple flow reactors in sequence where the reaction intermediates are not isolated but passed onto the next reactor component of the sequence. Each stream requires flow rate optimization to sustain required residence times and temperature effects for each reactor. Single reactors can be optimized for the reaction conditions conducted within the reactor but the situation becomes more complex when one reactor precedes another in sequence. Conditions are required to support each synthetic stage and a single reactor cannot be optimized by itself. The fine balance of conditions can lead to success or failure of such a flow system. By-products can be removed in-line through the use of phase-bound scavenging reagents. These small flow reactors have been shown to enable the use of unstable intermediates such as acyl azides formed as part of the Curtius rearrangement. The simplicity of the reactor sequence permits consideration of splitting synthetic sequences to permit the desired reaction control. An example of multistep synthesis is shown for the neolignin natural product grossamide. A system of three independent pumps delivering reactants through a series of valves using in-line monitoring and feedback control was operated under computer control.