Scaled-up Experiments Research Articles

Artificial photosynthetic system for diluted CO2 reduction in gas-solid phase

Rational design of robust photocatalytic systems to direct capture and in-situ convert diluted CO2 from flue gas is a promising but challenging way to achieve carbon neutrality. Here, we report a new type of host-guest photocatalysts by integrating CO2-enriching ionic liquids and photoactive metal-organic frameworks PCN-250-Fe2M (M = Fe, Co, Ni, Zn, Mn) for artificial photosynthetic diluted CO2 reduction in gas-solid phase. As a result, [Emim]BF4(39.3 wt%)@PCN-250-Fe2Co exhibits a record high CO2-to-CO reduction rate of 313.34 μmol g−1 h−1 under pure CO2 atmosphere and 153.42 μmol g−1 h−1 under diluted CO2 (15%) with about 100% selectivity. In scaled-up experiments with 1.0 g catalyst and natural sunlight irradiation, the concentration of pure and diluted CO2 (15%) could be significantly decreased to below 85% and 10%, respectively, indicating its industrial application potential. Further experiments and theoretical calculations reveal that ionic liquids not only benefit CO2 enrichment, but also form synergistic effect with Co2+ sites in PCN-250-Fe2Co, resulting in a significant reduction in Gibbs energy barrier during the rate-determining step of CO2-to-CO conversion.

Clean and sustainable recovery of valuable materials from InP scrap via controlled-pressure pyrolysis–spray condensation

Indium phosphide (InP) semiconductors play an irreplaceable role in optical communication, and with the expansion of the market scale, the amount of InP scrap, which has become an important secondary resource for recovering phosphorus and indium, has considerably increased. However, as a typical phosphorus containing material, InP scrap recycling is difficult and dangerous because phosphorus is flammable and releasing toxic and irritating smoke during combustion. In this study, a safe, clean, and sustainable “controlled-pressure pyrolysis–spray condensation” process is proposed. Firstly, InP is decomposed into phosphorus and indium under high-temperature conditions; phosphorus then evaporates into the vapor phase and is sprayed with warm water for condensation in water, whereas indium is enriched in the liquid phase. The feasibility of this process is proven by performing thermodynamic calculations and scaled-up experiments (hundred grams to kilograms) by using a self-designed equipment. At a decomposition temperature of 1323 K, micro-negative pressure, and holding time of 5 h, an indium ingot with a purity of 99.59 wt.% was obtained and the direct yield reached 98.2%. Industrial α-yellow phosphorus with a purity of >98 wt.% was obtained and safely stored in water, and the comprehensive recovery rate is >90%. The overall process produces zero waste gas, liquid, or residue. The new process is easy to implement in industrial applications when the equipment is fitted with a continuous feeding and discharging system. A convenient and safe method for the X-ray diffraction detection of yellow phosphorus is also developed in this study.

Phosphorus oxide promoted solid state hydrolysis of sodium borohydride for efficient onsite hydrogen production

The hydrolysis of solid sodium borohydride (NaBH4) as a hydrogen source for portable fuel cells offers the advantages of excellent safety and convenient storage, making it the optimal alternative to NaBH4 solutions. However, the hydrolysis process is relatively slow and requires the addition of a catalyst to enhance its efficiency. Recent studies have demonstrated that introducing H+ can effectively promote the hydrolysis of NaBH4. In this study, therefore, selects solid acid anhydride, phosphorus pentoxide (P2O5), as a promoter for the hydrolysis of NaBH4. By controlling the ratio of H+ to H− in the NaBH4–P2O5 system, the conditions for hydrogen production via NaBH4 hydrolysis are optimized. Subsequently, to cater to the requirements of portable fuel cell applications, the optimal NaBH4–P2O5 hydrogen production system is selected, with hydrogen generation rate being controlled by regulating water flow speed. In order to enhance the practical applicability of NaBH4–P2O5, the scale-up of hydrogen production from this system is also undertaken. Finally, to validate the practicality of this reaction system, integration with a proton exchange membrane fuel cell (PEMFC) toy car using the NaBH4–P2O5 hydrogen generation system is performed. The results indicate that a NaBH4 conversation exceeding 90 % can be achieved when the ratio of H+ to H− is approximately 0.14, and within the range of H+/H− ratios from 0.05 to 0.14, the maximum hydrogen density reached 6 %. Furthermore, it was found that adjusting the water flow rate only impacts the rate of hydrogen production without significantly affecting the NaBH4 conversion, which consistently surpassed 90 %. Similar high NaBH4 conversion, above 90 %, were also attained in the scaled-up experiments of the NaBH4–P2O5 system. When implemented in a 5W PEMFC, this hydrogen production system delivered an output power of approximately 1.76 W, thereby affirming its operational feasibility and effectiveness.

Bioremediation of Aflatoxin B1 by Meyerozyma guilliermondii AF01 in Peanut Meal via Solid-State Fermentation.

The use of microorganisms to manage aflatoxin contamination is a gentle and effective approach. The aim of this study was to test the removal of AFB1 from AFB1-contaminated peanut meal by a strain of Meyerozyma guilliermondii AF01 screened by the authors and to optimize the conditions of the biocontrol. A regression model with the removal ratio of AFB1 as the response value was established by means of single-factor and response surface experiments. It was determined that the optimal conditions for the removal of AFB1 from peanut meal by AF01 were 75 h at 29 °C under the natural pH, with an inoculum of 5.5%; the removal ratio of AFB1 reached 69.31%. The results of simulating solid-state fermentation in production using shallow pans and fermentation bags showed that the removal ratio of AFB1 was 68.85% and 70.31% in the scaled-up experiments, respectively. This indicated that AF01 had strong adaptability to the environment with facultative anaerobic fermentation detoxification ability. The removal ratio of AFB1 showed a positive correlation with the growth of AF01, and there were no significant changes in the appearance and quality of the peanut meal after fermentation. This indicated that AF01 had the potential to be used in practical production.

Carbazole-containing covalent triazine frameworks for efficient hydrogen peroxide photosynthesis from natural sunlight

Hydrogen peroxide (H2O2) photosynthesis via polymer photocatalysts is an environmentally friendly and sustainable method for H2O2 production. However, their efficiency is currently unsatisfactory due to limited dissociation and insufficient migration of photogenerated charge carriers. Constructing donor–acceptor (D-A) type polymer photocatalysts has been demonstrated to be a promising approach to improve their optical and electronic properties related to charge carrier separation and migration. Herein, we design two donor–acceptor (D-A) type carbazole-containing covalent triazine frameworks (CTF-PCZs), namely CTF-BPCZ and CTF-TPCZ. These CTF-PCZs are found to reduce the exciton binding energy (Eb) and enhance charge carriers transfer ability compared to non-D-A type CTF-HUST-1. Remarkably, CTF-TPCZ exhibit excellent H2O2 photosynthesis performance, achieving a rate of up to 10331 μmol g−1 h−1 from pure water under solar simulator (AM 1.5G), and 6039 μmol g−1 h−1 from pure water under natural sunlight irradiation in scaled-up photocatalytic experiments, significantly surpass those of all previously reported polymer-based photocatalysts. In-situ experiments provide direct evidence for intermediates involved in the photocatalytic process. Both experiments and DFT calculations reveal that the triazine ring fragment plays a crucial role in H2O2 photosynthesis through a two-step single-electron oxygen reduction reaction (ORR) and the carbazolyl group plays a crucial role in one-step two-electron water oxidation reaction (WOR).

Radiochemical isolation of 45Ti using ion chromatography

45Ti exhibits favorable decay properties for positron emission tomography (PET) imaging and can be easily produced by the bombardment of natural scandium (Sc) by protons using the 45Sc(p,n)45Ti nuclear reaction. However, separation of 45Ti from irradiated Sc targets is arduous due to the hydrolytic instability of Ti(IV) complexes, making it a significant bottleneck for routine application of this radionuclide. In the present work, we describe the development and optimization of an ion chromatographic separation method based on trapping of 45Ti on a hydroxamate-functionalized chelating resin and subsequent elution with oxalic acid at pH = 2.8. Under optimized conditions, this method enabled 45Ti-recovery of 61 ± 8% within 7 min. Sc contamination in scaled-up experiments was found to be only 3.0 ± 1.8 µg/mL. The resulting 45Ti-solution was directly used for complexation with CDTA as a model chelator, affording the corresponding [45Ti]Ti(cdta) complex with a radiochemical conversion of 73 ± 3%. Conclusively, this promising method could be transferred to automated synthesis modules and should enable the preparation of 45Ti-labeled compounds for PET imaging.

Microalgae growth using treated domestic effluent added to emerging pollutants: Removal mechanism and generation of by products

The objective was to assess the efficiency of microalgae metabolism in removing BOD5, COD, N, P, and emerging pollutants (EPs) from pretreated domestic effluent. Spirulina platensis and Scenedesmus obliquus were cultivated in standard medium with the addition of 5 % and 10 % pretreated domestic effluent every 5 d. The growth parameters, biochemical composition, and removal efficiencies were evaluated. Spirulina was scaled up to 10 L tanks with an open reactor, here using 10 % effluent and 20 μg/L of EPs (caffeine, fluoxetine, and acetylsalicylic acid) every 5 d. EP concentrations and the generation of degradation byproducts were monitored. Microalgae exhibited significant growth in both effluent additions, achieving biomass concentrations exceeding 1 g/L. After 30 days, all the physical-chemical parameters of the effluent were reduced (removals <80 %). The scaled-up experiments demonstrated removal of 39 % caffeine and 80 % fluoxetine after 30 d. EP degradation byproducts (theobromine and norfluoxetine) from caffeine and fluoxetine degradation showed EP biodegradation as a mechanism. Microalgae cultivation proved effective as a posttreatment method for the residual loads remaining after conventional treatment, and it can also target new fractions of pollutants in wastewater, reducing the risk to aquatic organisms. Moreover, the biomass of Spirulina platensis obtained after treatment exhibited high carbohydrate and protein contents (55 % and 29.18 %, respectively), showing potential as a source of bioenergy and biofertilizer products.

Nitro-Spirocyclization of Biaryl Ynones with tert-Butyl Nitrite: Access to NO2-Substituted Spiro[5,5]trienones.

A metal/peroxide-free involved simple cascade 6-exo-trig spirocyclization of tert-butyl nitrite with biaryl ynones has been finished, which resulted in various NO2-modified spiro[5,5]trienones with good regioselectivity/yields. A variety of scaled-up experiments, reduction/epoxidation operations, and mechanistic studies were performed to verify the merits and spirocyclization process of this radical system. Finally, the structure of the spirocycles was confirmed by single-crystal X-ray diffraction.

Exploring the parameter space of MagLIF implosions using similarity scaling. II. Current scaling

Magnetized liner inertial fusion (MagLIF) is a magneto-inertial-fusion (MIF) concept, which is presently being studied on the Z pulsed power facility. The MagLIF platform has achieved interesting plasma conditions at stagnation and produced significant fusion yields in the laboratory. Given the relative success of MagLIF, there is a strong interest to scale the platform to higher peak currents. However, scaling MagLIF is not entirely straightforward due to the large dimensionality of the experimental input parameter space and the numerous physical processes involved in MIF implosions. In this work, we propose a novel method to scale MagLIF loads to higher currents. Our method is based on similarity (or similitude) scaling and attempts to preserve much of the physics regimes already known or being studied on today's Z pulsed-power driver. By avoiding significant deviations into unexplored and/or less well-understood regimes, the risk of unexpected outcomes on future scaled-up experiments is reduced. Using arguments based on similarity scaling, we derive the scaling rules for the experimental input parameters characterizing a MagLIF load (as functions of the characteristic current driving the implosion). We then test the estimated scaling laws for various metrics measuring performance against results of 2D radiation–magneto-hydrodynamic hydra simulations. Agreement is found between the scaling theory and the simulation results.

Fabrication of highly active and stable Ni/CeO2-nanorods wash-coated on ceramic NZP structured catalysts for scaled-up CO2 methanation

The production of synthetic natural gas from CO2 methanation using green H2 produced via water electrolysis is a promising pathway regarding both the curtailment of excess power by variable renewables and the mitigation of CO2 emissions. Several catalytic systems have been employed for thermocatalytic CO2 methanation in lab-scale, with Ni-based catalysts being amongst the most cost-effective and active materials. In this regard, we have recently demonstrated the remarkable low-temperature CO2 methanation activity of a nickel catalyst supported on ceria nanorods, ascribed to the augmented metal-support synergy. Herein, we report on a scaled-up process of CO2 methanation, involving; i) fabrication of a highly porous NZP-type ceramic substrate of Ba1+xZr4P6–2xSi2xO24 in the form of extruded pellets, ii) wash-coating of Ni/CeO2-nanorods catalyst on NZP pellets, iii) design and testing of scaled-up experiments under a scaling factor of 80:1 and 65:1 in terms of mass and volume of catalysts compared to lab-scale experiments, respectively. The as-synthesized catalyst exhibited remarkable performance under variable reaction conditions and stable behavior after 75 h. Remarkably, the structured catalyst attained a methane formation rate of 277 NL gNi−1 h−1, being higher to numerous values reported in relevant works. Equally importantly, it was disclosed that increased values of space velocity led to high temperature gradient in the catalytic bed, thereby favoring the generation of CO. Intriguingly, the morphological and structural characteristics of the used catalyst remained unaltered even after various on/off reaction cycles and the stability test, which is a promising finding toward scaling-up the process at higher technology readiness levels using real feed streams.

Diverse continuous photooxygenation reactions of (+) and (−)-α-pinenes to the corresponding pinocarvones or trans-pinocarveols

The continuous photooxygenation reactions of (+) and (−)-α-pinenes are described, giving the corresponding (+) and (−)-pinocarvones (83% yield) and (+) and (−)-pinocarveols (61% yield). Scaled-up and long-term experiments (24 h) are also presented.

Scale-up modelling and life cycle assessment of electrochemical oxidation in wastewater treatment

The need to improve current wastewater treatments to ensure a clean and sustainable water supply is an unquestionable contemporary challenge. It is therefore essential to facilitate knowledge transfer between research institutions and the industry by developing novel technologies to a proof-of-concept stage, demonstrating both treatment efficiency and compliance with environmental criteria. This study has combined process modelling for the design of an electrochemical Advanced Oxidation Process (eAOP) to remove carbamazepine (CBZ) from wastewater with the identification of the environmental impacts associated with its operation. A comprehensive set of scenarios considering several reactor designs and operating conditions provides the assessment framework to identify the influence of different process variables on the environmental profile of the pilot-scale eAOP. The most sustainable treatment corresponds to the operation of a standardised modular reactor in batch mode, especially when the wastewater has a low concentration of scavengers, such as other ions, organics or pollutants. Nevertheless, in all scenarios evaluated, the main environmental hotspot was attributed to the electrical energy consumed by the auxiliary pumps rather than the electrochemical reactor itself. In comparison to other AOPs, our system showed considerably lower impacts in the global warming potential (GWP) category, with a minimum of 7.6 kg CO2 eq per g CBZ removed for the most promising scenario. This demonstrates the implementation potential of eAOPs as well as the importance of data from scaled-up experiments, where optimisation should focus on mitigating the impacts of energy-intensive pieces of equipment.

Free-Radical-Involved Trifluoromethylthiolation Cyclization of Alkenes To Access SCF3-Substituted Indolo[2,1-a]isoquinolines

AbstractFree-radical-promoted tandem trifluoromethylthiolation of alkenes with AgSCF3, which provides an efficient protocol for the construction of SCF3-modified indolo[2,1-a]isoquinolines with moderate to good yields. A series of scaled-up experiments, other substrate transformations, and radical inhibition experiments were operated to verify the merit of this reaction system.

Photoinduced Tandem Cyclization of Alkynes with Phenylsulfinic Acids: Access to Sulfone-Substituted Dioxodibenzothiazepines or Dibenzazepines

AbstractPhotoinduced tandem cyclization of alkynes with phenylsulfinic acids has been accomplished, which gives a mild strategy for the preparation of sulfone-substituted seven-membered N-heterocycles. A variety of scaled-up experiments, further transformations, and mechanistic studies were also operated in the follow-up work.

Free Radical Promoted Trifluoromethylthiolation of Alkynes to Access SCF3-Containing Dibenzazepines or Dioxodibenzothiazepines.

Persulfate-promoted radical cascade trifluoromethylthiolation of aryl acetylenes with AgSCF3 provides a simple reaction system for the synthesis of SCF3-substituted dibenzazepines or dioxodibenzothiazepines with good Z/E selectivity. The single-crystal X-ray diffraction data confirms the structures of the final products. A series of scaled-up experiments, further transformations, and radical inhibition experiments were operated in the reaction system.

An Improved Fault Detection Method for Overhead Transmission Lines Based on Differential Tunnel Magnetoresistive Sensor Array Approach

Overhead transmission lines play a key role in ensuring power system security and reliability in this current smart society. The overhead transmission line operates in a very complex terrain thereby making it vulnerable to various kinds of faults. Most transmission line faults lead to interruption in power supplies and therefore the need for a fast repair to restore the system to its normal state. A fast, timely, and accurate fault detection technique will ensure speedy restoration of the system thereby reducing outage time. In this article, an enhanced transmission lines’ fault detection approach is presented. This scheme deployed a highly sensitive, low cost, and energy-efficient differential sensor to detect flux density variation measured along transmission lines. The fault detection algorithm is developed for the detection of faults in transmission lines. The development is implemented on a model transmission line and tested for various fault scenarios. Scaled-up laboratory experiments were also conducted to measure magnetic flux density and fault identification to verify the validity of the proposed technique as well as estimate the amount of current produced when a fault occurred. From the simulated and measured current produced during a fault, the proposed technique yielded an estimated error of 1.38%, while the CT and a commercial current probe gave errors of 10.99% and 17.68%, respectively.

A Study into the γ-Al2O3 Binder Influence on Nano-H-ZSM-5 via Scaled-Up Laboratory Methanol-to-Hydrocarbon Reaction

Development of a laboratory selected zeolite into an industrial zeolite-based catalyst faces many challenges due to the scaling-up of reaction which requires many upgrades of the as-prepared catalyst such as an enhanced physical strength. To meet this requirement zeolite powders are normally mixed with various binders and then shaped into bulky bodies. Despite the fact there are a lot of reports on the positive features brought by the shaping treatment, there is still a great need to further explore the zeolite properties after the binder introduction. In this case, a lot of studies have been continuously conducted, however, many results were limited due to the usage of much smaller laboratory samples rather than a real factory plant, and more importantly, the maximal/minimal proportion of zeolites in the shaped catalyst. In this research, our shaped catalysts are based on nano-H-ZSM-5 zeolites and alumina (γ–Al2O3) binder while keeping the zeolite content to a maximum. H-ZSM-5 samples and Al-H-ZSM-5 samples are compared in the designed methanol-to-hydrocarbons reaction. With a reduced weight-hourly-space-velocity (WHSV = 1.5 h−1) and a higher reaction pressure (6 bar) favorable for aromatization, together with the tailored instruments for catalyst volume scale-up (20 g samples are tested each time), our tests focus on the early period catalytic performance (during the first 5 h). Unlike a normal laboratory test, the results from the scaled-up experiments provide important guidance for a potential industrial application. The role of the γ–Al2O3 introduced, not only as binder, but also performing as co-catalyst, on tailoring the early time product distribution, and the corresponding coke deposition is systematically investigated and discussed in details. Notably, the Si/Al ratio of H-ZSM-5 still has a decisive influence on the reaction performance of the Al-H-ZSM-5 samples.

Studies on temperature characteristics and initial formation interface during cyclopentane-methane hydrate formation in large-scale equipment with bubbling

In this work, temperature characteristics during hydrate formation were investigated in the cyclopentane-methane system using large-scale equipment with bubbling. The volume in each experiment was increased by a factor of 80 compared with previous work. A group of scaled-up experiments, under the optimal condition based on experiments in the smaller crystallizer, was carried out to verify the scale-up potential of hydrate-based thermal fluid production process. Another group of scaled-up experiments were performed with different variables (volume ratio of cyclopentane to water, gas/liquid ratio and pressure) to figure out the initial hydrate formation interface and optimize the temperature of the thermal fluid. Experimental results illustrate that hydrate-based thermal fluid production process can be scaled up by a factor of 80, however, the temperature of the thermal fluid needs to be optimized by adjusting variables accordingly. Moreover, the liquid cyclopentane/water interface more than the gas/liquid interface affects hydrate formation and hydrate accumulation. In particular, the hydrate formation interface initially occurs on the water side near the liquid cyclopentane/water interface. A large amount of hydrate accumulates in the bulk liquid cyclopentane phase, forming new hydrate formation interfaces. Thermal fluid with a specific temperature range can be produced based on the heat released and conducted from the hydrate formation interfaces.

Filling efficiency of flip-chip underfill encapsulation process

PurposeThis paper aims to introduce a new indicative parameter of filling efficiency to quantify the performance and productivity of the flip-chip underfill encapsulation process. Additionally, the variation effect of the bump pitch of flip-chip on the filling efficiency was demonstrated to provide insight for flip-chip design optimization.Design/methodology/approachThe filling efficiency was formulated analytically based on the conceptual spatial and temporal perspectives. Subsequently, the effect of bump pitch on filling efficiency was studied based on the past actual-scaled and current scaled-up underfill experiments. The latter scaled-up experiment was validated with both the finite volume method-based numerical simulation and analytical filling time model. Moreover, the scaling validity of scaled-up experiment was justified based on the similarity analysis of dimensionless number.FindingsThrough the scaling analysis, the current scaled-up experimental system is justified to be valid since the adopted scaling factor 40 is less than the theoretical scaling limit of 270. Furthermore, the current experiment was qualitatively well validated with the numerical simulation and analytical filling time model. It is found that the filling efficiency increases with the bump pitch, such that doubling the bump pitch would triple the efficiency.Practical implicationsThe new performance indicative index of filling efficiency enables the package designers to justify the variation effect of underfill parameter on the overall underfill process. Moreover, the upper limit of scaling factor for scaled-up package was derived to serve as the guideline for future scaled-up underfill experiments.Originality/valueThe performance of underfill process as highlighted in this paper was never being quantified before in the past literatures. Similarly, the scaling limit that is associated to the scaled-up underfill experiment was never being reported elsewhere too.

Continuous and scalable applications of microbial fuel cells: a critical review

The depletion of conventional energy sources has motivated countries to shift towards renewable and eco-friendly sources of energy. One of the major global energy consumers is wastewater treatment facilities, particularly biological processes. The microbial fuel cell (MFC) is an emerging biotechnology that has been proven to be able to treat a wide range of wastewaters while generating electricity. However, after two decades of extensive research, the MFC technology remains mostly trapped in laboratory experimentations studying its performance and potential improvements. Moving towards the commercialization of MFC technology, multiple studies have focused on its actual performance under realistic conditions, i.e., large-scale continuous operation. Scaling up MFCs has been tested by increasing the unit size, stacking individual cells, and/or using multiple electrodes. As more research had been carried out in this area, the aim of the present article is to review the various designs and configurations of continuous scaled-up experiments from treatment, power generation, and applicability perspectives. This review compiles more than one hundred research studies on continuous scalable MFCs. The key operation parameters, including the hydraulic retention time and organic loading rate, are thoroughly discussed to obtain practical optimum ranges in comparison to conventional treatment processes. The various scaled-up cell materials and configurations are analyzed and correlated to their reported performance. Design guidelines for process variables and system components/configurations are suggested, and relevant research gaps and challenges are identified.