An integrated reclaimed process of refining slag with calcium-containing wastewater for CO2 mineralization and utilization by using a high-gravity carbonation process was proposed in this study. The effect of various liquid agents on calcium ion leaching behavior from the refining slag was determined and the mass-loss method was used to evaluate the leaching kinetics. The influence of different high gravity factor and liquid-to-solid ratio on carbonation conversions were investigated and the reaction kinetics were identified via surface coverage model. The efficacy of refining slag utilized as supplementary cementitious materials including workability and mechanical strength was assessed. The morphological, mineralogical and thermal analyses were carried out and the results revealed the presence of calcite to support the carbonation theory. The results of maximal CO2 capture capacity of 0.183 g CO2 per g slag and performance of carbonated slag utilization with 5% and 10% substitution ratio confirmed the feasibility of the integrated reclaimed process.

Transformation of sugars is a sustainable way for production of high value-added chemicals and fuels. Traditional procedures used H2SO4 for sugar dehydration, followed by hydrogenation with fossil-derived hydrogen over noble metal catalysts, which increased the complexity and cost. In this work, formic acid (FA) served as both acid catalyst for dehydration of xylose and hydrogen donor for hydrogenation of as formed furfural (FAL) with N-doped carbon confined Co (Co-N-C) as catalyst. High furfuryl alcohol (FOL) yield of 69.5% was accomplished at 160 oC for 5 h. Kinetic studies showed that the apparent activation energy (Ea) over Co-N-C was calculated to be 98.8 kJ/mol. This catalyst was also capable for one-pot transformation of xylan to FOL and could be reused 5 times. It is found that the xylose dehydration could be rate-determined step and coupling xylose dehydration with FAL hydrogenation could accelerate the xylose transformation and the generation of FOL.

Abstract In this work, we offered a facile strategy to produce lignin microspheres (LMS) with loading benzotriazole (BTA) inhibitors which were released as the pH changed. The morphological and compositional characterization demonstrated that the BTA inhibitors were efficiently encapsulated in the LMS whose load was up to 15.5 wt%. Tests of crossed scratches of coatings indicated the [email protected]/pure waterborne epoxy resin (WEP) had a good self-healing property. By electrochemical impedance spectroscopy (EIS) test, the long-term anticorrosion property of [email protected]/WEP composites was one order of magnitude higher than that of WEP, which indicated that the [email protected] greatly improved the corrosion resistance. The highly effective anticorrosion should be attributed to the pH-responsive release behavior of BTA from lignin microspheres, which actively protected the steel substrate. The enhanced anticorrosion and the controlled release of BTA enlarged the high value-added applications of lignin.

This simulation study demonstrates the scalability of chemical looping combustion (CLC) to achieve efficient capture of biomass derived CO2. To achieve this, a 3D computational particle fluid dynamics (CPFD) simulation is implemented using a Barracuda software. The process considers syngas from biomass gasification as a fuel, as well as a highly performing nickel-based oxygen carrier (HPOC). A recently developed solid-state model is used to describe the HPOC CLC kinetics. The proposed CLC system includes two interconnected reactors: a) a riser air reactor and b) a downer fuel reactor. An oxygen carrier is circulated in a controlled manner via a newly implemented L-type loop seal, which is operated with air pulse device. CPFD models are considered, to assess the CLC unit performance. The CPFD simulation demonstrates that a 100 kW CLC reactor yields a 92% CO2 capture in both a 10m and 12m downer using a single unclustered and clustered particle models, respectively.

Developing more sustainable products requires innovative ways to utilize and modify renewable resources. Here a simple one-step in situ modification of regenerated cellulose beads using cellulose nanocrystals (CNC) and drop-wise precipitation of cellulose/N,N-dimethylacetamide and lithium chloride (DMAc/LiCl) solution is presented. A more condensed internal structure and increased surface roughness were observed when higher CNC concentrations were used in the precipitation media. Incorporation of CNCs significantly reduces water holding capacity of the beads and simultaneously impacts the kinetics of drying. Beads modified using the highest CNC concentration (0.5 wt.%), exhibited a reduction in the Young modulus by more than 20% and an increase in compressibility to failure by 10% compared with native beads. Overall, inclusion of nanoparticles during bead formation is a simple method that can tune the mechanical, structural and swelling/drying behavior of cellulose beads and broadens their potential for different end-use applications such as separations and controlled release.

Layer-by-layer (LbL) assembly often requires numerous deposition steps to obtain a suitable thickness for an effective flame retardant nanocoating. In an effort to make this technique more industrially feasible, an amine salt is added to the rinsing steps of a chitosan/sodium hexametaphosphate (CH/PSP) multilayered system, to help facilitate thicker growing films with self-extinguishing capability and fewer processing steps. Cotton fabric coated with CH/PSP is rinsed in water baths containing tris(hydroxymethyl)aminomethane [THAM] and compared to control samples rinsed with deionized water. Only 10 bilayers of the CH/PSP system rinsed with THAM is required to achieve self-extinguishing behavior and pass a vertical flame test, while 15 bilayers of the control system is needed to achieve similar results.

To treat industrial suspensions efficiently using cost-effective membrane filtration technology, we report the design and efficient construction of a bilayer Al2O3/ZrO2 membrane on a macroporous substrate with an optimized membrane structure and membrane material. To produce the membrane, an Al2O3 layer (pore size = 100 nm) was first deposited on the substrate to prevent layer penetration issues, and the thickness of the membrane was optimized using the Hagen–Poiseuille and Darcy equations to model the membrane resistance. A thickness of 6–10 μm was found to be sufficient to cover the rough ceramic substrate. Then, a ZrO2 layer (mean pore size = 50 nm) was added to the wet Al2O3 layer. On the basis of the individual sintering behaviors of each layer, the Al2O3 and ZrO2 layers were co-sintered at an appropriate sintering rate, which significantly reduced the energy consumption and fabrication period. Membranes having a pore size of ~50 nm achieved a higher permeance (650 L m 2 h 1 bar 1) than those reported in the literature. In the treatment of kaolin suspensions, the membranes showed great potential for reducing the turbidity (by nearly 100%) of the suspensions and showed highly stable permeate flux and good regeneration performance, even at high turbidities. This work provides a comprehensive research into the design and construction of cost-effective membrane materials for industrial suspension separation process.

Microfluidic systems on different porous substrates (particularly paper-based devices) have gained significant popularity in recent times for diversified applications ranging from bio-analytical applications for healthcare technologies, green energy generation to flexible electronics. In this short review, we attempt to provide a concise overview about its theoretical perspective starting from the understanding of flow in single one-dimensional category. Furthermore, we discuss about the two specific applications (blood plasma separation and energy generation) on these devices; which are solely triggered by the intrinsic capillarity action of the porous media. These two specific examples delineate the fact that flexible architecture of the devices in combination with the inherent capillary force makes it suitable to meet the challenging requirements; thus, become extremely suitable for the low resource settings environment.

The ability to experimentally control structural features of Activated Carbons (ACs), combined with current advances in modeling carbon-based materials at the atomic level, allows building predictive models for process design of novel applications. This contribution is devoted to molecular simulations of CO2 in ACs, starting from building the atomistic adsorbent model, validated with experimental results, and simulating its application for CO2 capture and separation by adsorption. Single components and competitive adsorption data of binary mixtures from different industrial streams (e.g., CO2/N2 and CO2/CH4) were obtained by grand canonical Monte Carlo (GCMC) simulations, performed at typical operating conditions for the separation of streams associated with post-combustion and natural gas sweetening. We employed a previously published modeling technique to represent activated carbons, based on packing non-interconnected functionalized fragments of carbon sheets with surface heterogeneities. GCMC simulations were first used to calculate adsorption isotherms and isosteric heats to analyze the performance of the ACs for CO2 capture. Predicted process parameters such as working capacities and purities were evaluated and complemented with energetic performance for swing adsorption processes, with and without pre-adsorbed traces of water. Results show that the presence of pre-adsorbed water does not significantly affect the adsorption performance, but it influences the energy consumption of the process. Furthermore, a small amount of water can improve the CO2 capture performance in some specific cycles at low pressures.

A Thiele modulus – effectiveness factor method was applied to provide insight into the interplay of intraparticle mass transfer and intrinsic adsorption kinetics in non-equilibrium adsorption processes. A full model and two approximate methods were considered. In the approximate methods only the fluid concentration at the external surface and the averaged sorbent loading are required as input. Assuming a uniform sorbent loading, an explicit solution for the effectiveness factor for adsorption as a function of the Thiele modulus for adsorption was derived. For each adsorptive system a minimum and maximum Thiele modulus can be calculated, which provide a priori insights regarding the rate determining step. The approximations were validated against complete numerical solutions for a single particle and their use was compared to a complete particle description within a full reactor-particle model. Results for CO2 adsorption from flue gas and ambient air showed that the approximations result in a good accuracy for the applications studied.

Solar energy is an intermittent resource and thus an energy storage system is required for practical applications of the collected solar irradiance. This work deals with the integration of a thermo-chemical energy storage (TCES) system based on the Calcium Looping (CaL) process with a concentrated solar tower power (CSP) plant. The objective of this work is the integration of a conventional 320 MWe Rankine cycle with a direct calcination for the energy harvesting. Particularly, this work addresses the use of CO2 as the working fluid of a compressed–gas energy storage (CGES) system for hybrid energy storage with CaL process. The hybrid TC/CG–ES (Thermo–Chemical/Compressed–Gas Energy Storage) system can increase the competitiveness of the CSP with respect to conventional fossil-based power plants leading to a reduction in CO2 emissions. The thermal integration with the Calcium Looping (CaL) system is optimized by means of the pinch analysis methodology. The obtained results show a reduction in the electrical efficiency of about four percentage points with respect to the conventional Rankine power cycle without CSP unit: the net electrical efficiency reduces from 43.7% to 39.5% while the global (thermal and electrical) efficiency of the plant reaches the peak value of 51.5% when low enthalpy energy is recovered (e.g. district heating network, district cooling network). The paper highlights the importance of the thermochemical CaO based material. With a conversion of CaO to CaCO3 of 80% the storage efficiency defined as the ratio of the energy released during the carbonation and the CO2 expansion

Optimal control theory is applied to dynamic operation of batch reverse osmosis (RO) for seawater desalination and batch pressure retarded osmosis (PRO) for power generation. It is proved that the water flux should be constant during the entire operation in order to minimize specific energy consumption (SEC) in RO or to maximize specific energy production (SEP) in PRO. A dimensionless parameter $\gamma = A_m L_p\pi_0t_f/V_0$, similar to the one used in continuous osmotic membrane processes, is proposed to characterize the energy performance. While the SEC in RO is a monotonic function of recovery and $\gamma$, the SEP in PRO is solely a monotonic function of $\gamma$. It is shown that batch RO/PRO excels continuous RO/PRO because it mitigates the spatial variation of flux in a long pressure vessel observed in the latter. The batch operation provides an elegant way to implement continuous multi-stage RO with interstage pumps and an energy recovery device (ERD) as well as continuous multi-stage PRO with interstage turbines. Some tradeoff between energy efficiency and flux is deemed necessary. A preliminary cyclic diagram to operate the batch PRO is proposed.

Thin Film Evaporator (TFE) is a popular continuous distillation/evaporation technology for pharmaceutical and fine-chemical industries, and has several equipment- and process- configurations that make fundamental modeling approaches very challenging. Specifically, moving wipers and lack of fluid dynamic and intra- and inter- phase mixing knowledge contribute to the difficulty of developing predictive models. In this article, we present a novel, simple, and practical TFE model developed for Active Pharmaceutical Ingredient (API) continuous manufacturing. The model couples thermodynamic and counter-current N-CSTR models, and is capable of predicting TFE performance using various process parameters as inputs. Model’s expanded usage is detailed for the case where the distillate to feed ratio was used to control the TFE.

Alkali and alkaline metal (Li, Na, K, Ca and Mg) loaded zirconium oxide catalysts were prepared by wet impregnation method. All the prepared catalysts were employed as active heterogeneous catalysts for the transesterification of glycerol (GL) with dimethyl carbonate (DMC) producing glycerol carbonate (GLC). The catalyst with 20 wt% loading of Li on ZrO2 showed maximum catalytic activity with 100% selectivity towards GLC. The structure and basic properties of the prepared catalysts were studied by XRD, HRTEM, XPS and CO2-TPD techniques. The effect of various reaction parameters like catalyst concentration, reaction temperature, the molar ratio of reactants on the GLC yield was also studied. For the first time the reaction product was quantified using 1H NMR technique. Considering the lesser availability of the kinetic study of the transesterification of glycerol with dimethyl carbonate, kinetic parameters were also studied. The Li/ZrO2 catalyzed transesterification reaction appeared to follow second order kinetics with activation energy (Ea) of 93.7 kJ mol−1. Thermodynamic parameters like enthalpy (ΔH‡), entropy (ΔS‡) and Gibbs free energy (ΔG‡) of the reaction were also determined.

Multilayered shape-memory composites composed of multi-walled carbon nanotubes (MWCNTs) filled thermoplastic polyurethane (TPU) (denoted as cTPU) and polycaprolactone (PCL) were prepared through layer-multiplying coextrusion. The phase interfaces and conductive pathways in the multilayered structure which can be tailored by layer-multiplying endowed the materials with tunable thermo- and electro-responsive shape-memory effects (TSME and ESME). Compared with the conventional blending composite having the same compositions, the cTPU/PCL multilayered system with high phase continuity and abundantly continuous interfaces exhibited better TSME, which could be further enhanced with increasing the layer number. It was revealed that the strain energy stored in cTPU layers would be balanced by adjacent PCL layers via interfacial shearing effect so that each domain could endow the maximum contribution to the shape-memory performance. Besides, the confined layer space allowed for a more compact connection between MWCNTs than that in the blending composite, while the original conductive network formed in cTPU tended to be gradually broken up during layer-multiplying. Moreover, an excessive conductivity may induce local overheating and even the melting of permanent domains, leading to undesired deformation. Accordingly, the multilayered composite with a proper layer number which exhibited suitable conductivity and efficient TSME achieved balanced ESME with quick recovery speed, excellent recovery ratio and good appearance retention. This work opened an avenue in preparing outstanding shape-memory materials with both thermal and electrical actuations, which showed great potential in applications of sensors, actuators, self-deployable devices, and so forth.

New fire barriers combining the use of two different intumescent paints and a metal laminate structure have been evaluated for the protection of steel. Different bilayers designs have been considered and composed of the overlay of two intumescent coatings with or without aluminum foils. All laminated bilayers were fire exposed in a high heat flux environment (116 kW/m2). The design with two aluminum foils and the overlay of both intumescent coatings reveals an efficient fire protection with a stabilization at low temperature after 30 min fire exposure. This design exhibits much higher performance than that of conventional intumescent coating. Characterizations (cross-section observations, expansion measurements, pull-off tests) were carried out on all samples to clarify the mechanism of action. This paper reveals a new way of thinking, and highlights that working on the design instead of changing the formulation of the intumescent paint allows to reach an efficient fire resistant barrier.

Every critical online unit in a continuous process must always function normally, and one or more identical unit is usually put on standby to sustain the uninterrupted operation. Although a few related studies have been reported in literature, a comprehensive analysis of the standby mechanism still has not been carried out. The objective of this research is to construct a generalized mathematical model to synthesize the multi-layer standby mechanisms for any given processes by minimizing the total expected lifecycle expenditure. A Matlab code can be developed accordingly to perform the required optimization tasks via genetic algorithm. The feasibility and effectiveness of the proposed approach have been demonstrated with the case studies concerning the pump system in a typical chemical plant. From the optimization results, one can obtain the optimal design specifications of the multi-layer standby mechanism, which include: (1) the number of layers, (2) the numbers of both online and spare sensors in each measurement channel, (3) the corresponding voting-gate logic in each channel, (4) the inspection interval of switch, (5) the number of spares for switch, (6) the inspection intervals for warm standbys and (7) the number of cold standbys. Keywords: Standby mechanism; Availability; Expected loss; Genetic algorithm

Deep eutectic solvents (DESs) are a class of green solvents that hold promising application in gas separation. With respect to NH3 separation, realizing reversible chemical absorption of NH3 is demanded, because the contents of NH3 in industrial streams are normally low. In this study, we found that N-methylacetamide (MAA) can form DESs with heterocyclic weak acids (HWAs) such as imidazole, 1,2,4-triazole and tetrazole. The DESs were characterized for physical properties, and evaluated for NH3 absorption performance systematically. The solubilities of NH3 solubilities in MAA+tetrazole DESs are much higher than those in MAA+imidazole and MAA+triazole DESs, since tetrazole is more acidic than the other two HWAs. In addition, the isotherms for NH3 absorption in MAA+tetrazole DESs display non-ideal profiles, suggesting the chemical behavior of NH3 absorption, which is further elucidated by quantum chemistry calculations and spectroscopic characterizations. Overall, MAA+tetrazole DESs are among the best solvents for NH3 absorption, with the NH3 solubility of 4.596 mol/kg at 313.2 K and 9.0 kPa. The absorption of NH3 in MAA+tetrazole DESs also show excellent selectivity over CO2, and good reversibility throughout consecutive cycles, justifying the potential use of MAA+tetrazole DESs for NH3 separation from industrial streams.

In this study, vapor-liquid equilibria (VLE) of binary, ternary, and quaternary systems containing fragrances were predicted using COSMO-SAC. A model variant including multiple energies for the description of different hydrogen bonds (alcohol-alcohol, alcohol-ketone, alcohol-ether) was used. Based on equilibrium vapor compositions, odor intensity and character of fragrance mixtures were calculated using Stevens' power law for olfaction intensity scale and stronger component model for quality perception. Very good agreement between predicted and measured data was obtained with COSMO-SAC. Model predictions were similar to UNIFAC outcomes, but without using any binary interaction parameter. Based on these results, this study also indicates the possibility to use COSMO-SAC to predict VLE in mixtures that contain fragrances with missing UNIFAC parameters.

In the refinery process, a vast amount of data are generated in daily production. How to make full use of these data to improve the simulation's accuracy is crucial to enhance the refinery operating level. In this paper, a novel deep learning framework integrating the self-organizing map (SOM) and the convolutional neural network (CNN) is developed for modeling the industrial hydrocracking process. SOM is used to map input variables into two-dimensional maps to extract process features. Then these maps are fed into CNN to predict the outputs of the hydrocracking process. The SOM adopted is free of training, which reduces the computational complexity, simplifies the application, and improves the prediction accuracy. Practical guidance on the application of the proposed framework is provided by comparing and analyzing different structures and parameters. Finally, an online modeling scheme is developed and applied in an actual hydrocracking process. Experimental results demonstrate that the proposed framework has great performance in modeling the hydrocracking process and provides a good reference for process optimization.

Reduction of photocatalytic CO2 into renewable hydrocarbon solar fuels is considered to be a promising strategy that can simultaneously address global energy needs as well as the environmental concerns. To date, making use of a higher wavelength for photocatalytic conversion of CO2 to CH4 continues to be highly challenging. In this work, we report a highly selective reduction of CO2 into CH4 and CO through doping Ni species into CoFe-LDH as the visible light photocatalyst in conjunction with a Ru-complex sensitizer. A more interesting finding is that the selectivity of CH4 was raised to 78.9% as compared to 0% of CoFe-LDH, while the H2 evolution was suppressed to 1.7% as compared to 30.5% of CoFe-LDH under light irradiation at λ > 500 nm. The involvement of Ni2+ ions in the CoFe-LDHs layers has shown to promote the photoinduced electron-hole pair separation and thereby facilitate the photocatalytic efficiency. This work provides a new strategy for exploring the Ni-based earth-abundant photocatalysts for CO2 photoreduction.

Solvent vapor exposure could transform a crystalline or smectic liquid crystal (LC) film into nematic and isotropic phases under ambient conditions. The average time for such phase transitions are found to linearly reduce with increase in vapor pressure and reduction in molecular weight of solvents. Such responses of solvent vapor annealed phase transitions of a nanoparticle loaded LC droplet was then converted into an electrical signal wherein the electrical resistance reduced (increased) with time upon destruction (restoration) of orientational order of the LC matrix. Variation in electrical response was used to identify the volatile organic vapors, phase transition of LCs, rate of diffusion-absorption of solvent into LCs, and rate of desorption-evaporation of solvent from LCs. Pattern directed phase transitions on physically heterogeneous surfaces showed a faster (slower) kinetics on the thinner (thicker) patterns. However, for chemically heterogeneous surfaces, weaker (stronger) anchoring of LCs on hydrophobic (hydrophilic) patches ensured a faster (slower) transition.

A series of Cu-loaded biomass-derived activated carbon (Cu/AC) catalysts with various impregnation ratios were prepared by precursor impregnation (PI) and activated carbon impregnation (ACI) methods. N2 adsorption/desorption, ICP, XRD, XPS and TEM, etc. were used to investigate their physico-chemical properties. Their performance of catalytic wet air oxidation (CWAO) of phenol using O2 as oxidant were evaluated. The results demonstrated the catalysts prepared by PI method have higher specific surface area and Cu content. In the catalysts, Cu species co-existed with Cu2+ and (Cu+ + Cu0). The content of (Cu+ + Cu0) in PI catalysts was higher, which was favorable for the formation of free radicals (O2-· and HO·), and then improved conversions of phenol and COD. The PI catalyst prepared with impregnation ratio of 3 exhibited the best catalytic activity for phenol oxidation. Meanwhile, the loss of Cu species was the main cause of catalyst deactivation.

Heterogeneous Electro-Fenton (EF) enables rapid elimination of recalcitrant organic pollutants without producing undesirable by-product, but a stable functioning of such processes remains challenging. In this work, a porous composite of ferric oxide/nitrogen/carbon (Fe2O3/N-C) with good EF activity and stability was fabricated from iron-based metal organic framework compounds (MOFs) and polyaniline via one-step pyrolysis. The incorporated Fe2O3 nanocrystals and the pyridinic and pyrrolic N species substantially render the material high catalytic activity for hydrogen peroxide (H2O2) generation and activation. Efficient degradation of bisphenol A and several other organic pollutants, dominated by heterogeneous EF pathway was achieved in acidic solution. The catalyst had low Fe leaching (0.52 mg/L after 2-h reaction) and remained 98% of its original activity after 4 cycles of repeated use. Therefore, the Fe2O3/N-C may serve as efficient, stable and environmentally-benign heterogeneous EF catalyst for wastewater treatment and environmental remediation applications.

Although functionalization is known as a promising way to notably improve the performances of ionic liquids (ILs) in separation processes, studies thereon are mainly experimental trial-and-error based while rational design of functional ILs is scarcely reported. In this work, computer-aided IL design (CAILD) and molecular dynamics (MD) simulation are combined towards rationally functionalizing ILs for the enhanced extractive desulfurization (EDS) of fuel oils. First, the UNIFAC-IL model is extended based on experimental data to specifically cover interaction parameters associated with four functional groups (i.e., hydroxyl, methoxy, vinyl, and cyanomethyl). A mixed-integer nonlinear programming (MINLP) problem is then formulated for the computer-aided design of functional ILs for the EDS task. Finally, MD simulations are performed to study the intermolecular interactions between the top IL candidates and model fuel oil components; by comparing with those for literature-reported ILs, the enhanced EDS performances of the designed functional ILs are well rationalized.

The aim of this work is to develop a Sliding Mode Control (SMC) scheme to keep an operation of a flash distiller in the Feasible Operating Region (FOR). Flash distillation is characterized as a simple single-phase separation system but operationally complex because it has a strong non-linear behavior due to the thermodynamic equilibrium, obligatory to reach the required component separation. Control of flash distillation processes must guarantee a good performance and robustness to get pre-separation quality before entering to next fractional distillation processes. A Phenomenological Based Semi-Physical Model (PBSM) is used here to represent the flash distillation process. The proposed control structure tries to avoid the biggest problem of the flash distiller, its recurrent restart due to temperature disturbances in the feed flow. The suggested control schemes, applied to a given separation, allow regulation of the pressure and the liquid level of the flash drum, keeping also the concentration of Propylene Glycol (PG) at the flash vapor outlet near to its set point, rejecting temperature disturbances. The simulation results show the features of the proposed controllers, which overcome some of the disadvantages of typical flash distiller controllers operating in the design conditions

The impact of the synthesis conditions on the structure and the radionuclide adsorption capacity of silylated clay minerals were evaluated in this study. Two green solvents were selected in this work, Phenoxypropanol and Glycerol respectively, and various synthesis temperatures (30, 60 and 90°C) were tested for the preparation of 3-aminopropyltriethoxysilane (APTES) functionalized Laponites®. The resulted adsorbents exhibit various extent and location of the grafting reaction as a function of the used solvent and temperature. These modifications of the reactivity of the materials also impact adsorption and desorption properties of Co2+ and Sr2+. Whereas the two ions are well-adsorbed whatever the synthesis conditions and even in bi-solute experiments, the adsorption capacity is not systematically proportional to the amount of loaded APTES, highlighting the specific impact of the synthesis conditions. Finally, the very limited desorption in saline solutions suggests that the synthetized adsorbents display suitable properties for the removal of radionuclides from aqueous solutions.

The hydrodynamics and local turbulent mixing of parallel multiple liquid jets, submerged in liquid, were investigated by means of experiments and computational fluid dynamics (CFD). A renormalization group (RNG) k-ε turbulence model was used to simulate the flow field. The model was validated experimentally by particle image velocimetry (PIV) measurements. In the converging region adjacent to the nozzle exits, the recirculation region disappears, and there is only ambient fluid entrainment. Different jet arrays were compared to evaluate the effects of jet spatial arrangement on the hydrodynamics and mixing performance. A shorter mixing length in the merging region suggests that mixing is more efficient in the triple jet system than in other jet systems. Compared with the jet Reynolds number, the jet spacing plays a more significant role in determining the critical mixing regions, while the linear relationship between them is more sensitive than that for multiple parallel plane jets.

Silicon anode is a key component for high-energy lithium ion batteries (LIBs). Electrode binder engineering for Si anode has been calling increasing awareness. Here, we report a series of molecularly engineered conductive polymer binder, i.e., star-like polyaniline (s-PANi), cross-linked polyaniline (c-PANi) and linear polyaniline (l-PANi). As conductive binder, the molecular structure of PANi was found to play a key role in determining the performance of Si anode: reversible capacity of 1776 mAh g-1 after 100 cycles at 500 mA g-1 was achieved using s-PANi as conductive binder, far superior than systems adopting c-PANi, l-PANi and conventional Carboxymethyl cellulose (CMC) binders. The correlation between binder molecule structure and Si-anode performance is found: star-like molecular structure is more advantageous over heavily cross-linked structure for it offers 3D-conjugated conductive network that are more resistant to cycle-induced large strain.

The fabrication of suspended gold/carbon composite nanofibers on carbon micro-posts by electrospinning of a gold/polyacrylonitrile (AuNP/PAN) blend precursor is proposed. The fibers were spun on a rotating drum collector for a short duration and carbonized at 900 oC in inert atmosphere. The in-situ fabrication of a monolithic carbon structure consisting of carbon nanofibers on carbon micro-posts ensures good electrical connection, thereby reducing ohomic resistive mismatch. It was found that the conductivity can be simply tuned about an order of magnitude as compared to virgin carbon nanofibers by the addition of gold nanoparticles. The conductivity was found to be increased with the size (5-20 nm) of the gold nanoparticles which engendered graphitic micro-regions in the pyrolyzed nanofibers. The effect of micro/nano fabrication technique on the organization of graphitic planes in the electrospun composite nanofibers studied experimentally and computationally and a templating effect of gold nanoparticles that causes enriched graphitization is proposed.

Nobel metal Pt composites show high catalytic activity for hydrogen evolution reaction (HER) but limited in application by high Pt contents and therefore, the cost. Herein, a series of Pt nanoparticles (NPs) deposited 2D Ti3C2Tx MXene were prepared by atomic layer deposition (ALD) method with relatively low Pt contents (0.98~3.10 wt%) and showed excellent HER catalytic activity and stability. The electrochemical results indicated that the prepared catalysts showed the optimal HER activity as the ALD deposition cycle reached 40, with overpotential of 67.8 mV approaching that of the commercial Pt/C catalyst (64.2 mV). The excellent behavior was attributed to the homogeneous dispersion of the Pt NPs and the good conductivity of the 2D Ti3C2Tx MXene supports.

A detailed techno-economic analysis of a novel Direct Air Capture (DAC) process has been carried out. In this process, carbon dioxide is separated from ambient air through wet scrubbing with an aqueous potassium hydroxide solution, while the solvent regeneration and CO2 recovery is carried out through Bipolar Membrane Electrodialysis (BPMED), a novel process exclusively based on electrical-driven regeneration. The results of the techno-economic analysis showed that the regeneration process could be less energy intensive than other solutions, requiring as low as 236 kJ/mol-CO2. However, the high costs of bipolar and ion exchange membranes make the BPMED expensive. In the base-case scenario the total capture cost has been found to be 773 $/ton-CO2, in line with previous cost estimates for DAC, but large for a 2nd generation process. As for other DAC processes, this solution could become particularly interesting in the future, whenever cheaper renewable energy and more affordable and improved membranes become available.

Crystallisation is an important separation unit operation accounting for nearly 90% of organic molecules in the pharmaceutical and fine chemical industries. Recently, continuous crystallisation was demonstrated to have several advantages over the conventional batch crystallisation in terms of improved product consistency, reduced labor costs/economic footprint and better process control. Continuous stirred tank crystallisers, however, are limited in mixing/ heat transfer capabilities and have issues like cyclical oscillations in product quality. Tubular crystallisers can mitigate these issues, however, suffer from issues related to particle settling and blockages. Fluidic oscillators with one or more feedback channels are gaining popularity in recent years due to the advent of microfluidics. Jet oscillations in fluidic oscillators were shown to consistently provide vigorous mixing and heat transfer above a critical Reynold’s number. In the present study, the feasibility of the fluidic oscillator as a continuous crystalliser was evaluated to mitigate challenges faced by previous continuous crystallisation technology. A novel ‘loop setup’ was proposed for continuous crystallisation and was investigated using the seeded anti-solvent crystallisation of paracetamol in a methanol-water system. The effect of key operating conditions of residence time, supersaturation ratio, operational mode, fluidic device, device orientation and seed size were investigated. Throughout the study it was observed that the loop setup gave product particle size distributions consistent with enhanced mixing behavior. Further, it was demonstrated that the proposed continuous crystalliser was better in terms of scale up in comparison with batch crystallisers. The presented results and approach will be useful to develop fluidic oscillators as a useful platform for continuous crystallization.

The electric field plays a key role in producing required fibers during electrospinning process. The effects of electric field on the jet motion, resultant fiber diameter, fiber membrane thickness, crystallinity and mechanical properties induced by three different melt electrospinning systems were investigated in this work, in a comprehensive and systematical manner. Intended for thoroughly understanding the electric field distribution, the numerical simulation was used in the experiment. And besides, the high-speed photography was adopted, with the objective of capturing the related and necessary images in the process of jet motion. Our simulation and experimental results indicated that both direction and intensity of electric filed play an important role in jet motion and resultant fibers properties, that is, an enhanced electric field with the same direction as original electric field results in a fiber with finer diameter, larger crystallinity and better mechanical performance due to higher whipping amplitude, greater whipping frequency and more efficient stretching of the jet; by contrast, the electric field distribution with opposite direction created by auxiliary electrode with inverse voltage produces an non-uniform fiber with larger diameter, smaller crystallinity, poorer mechanical performance and fluffy fiber membrane because of unstable jet motion and inefficient stretching.

We developed a novel technique based upon time-lapse InfraRed (IR) images to relate the effects of crude-oil oxidation kinetics on flow during one-dimensional homogeneous and heterogeneous laboratory-scale combustion tube experiments.} We performed combustion tube experiments under variable conditions including different sands (i.e., grain-size distribution), air injection rate history (constant versus variable), degree of packing heterogeneity and reaction heterogeneity. The latter is achieved by using reaction enhancing nanoparticles in controlled packing configurations. During every experiment, we obtain high-resolution IR images of the outer wall of the combustion tube that we calibrate using point-wise temperature measurements from a thermocouple. Here, a new experimental workflow that uses these images and combines knowledge obtained from kinetic cell experiments is used to isolate the spatial zones within the tube where so-called, low-temperature and high- temperature oxidation (pseudo-reaction regimes) occur during combustion tube experiments for the first time. Additionally, the IR imaging technique is shown to provide new insight into the propagation of the combustion front in homogeneous and heterogeneous systems and, importantly, visualizes gravity drainage of hot oil