The 50 most-cited articles in Industrial & Engineering Chemistry Research, 2020

Abstract This contribution provides a conceptual analysis and a quantitative comparative assessment of three technology chains that enable a carbon neutral chemical industry in a net-zero-CO2 world. These are based (i) on the use of fossil fuels and current chemical processes and infrastructure coupled with carbon capture and storage (CCS route), (ii) on the use of captured CO2 as a feedstock together with “green” hydrogen in new chemical processes (CCU route), (iii) on the use of biomass grown and processed for the specific purpose of making chemicals (BIO route). All routes are feasible and have different pros and cons. Such pros and cons are first discussed through a qualitative comparison of the three routes for a generic chemical product, and are then quantitatively assessed for the specific case of methanol production. In this case, the CCU route results in an electricity consumption 10 to 25 times higher than that of the CCS and BIO routes (excluding the electricity required for heat production), mostly due to the electricity required to produce hydrogen. At the same time,…

Zinc oxide (ZnO) nanoparticles were synthesized by the hydrothermal method and incorporated with diverse amounts of the nonmetal element sulfur (0.5, 0.8, 1.1, 1.3, 2.1, 2.5, 3.2, 6.8, 7.8, 11.9, 12.3, and 17.4 wt %). The physicochemical properties of all nanoparticles were investigated by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and N 2 adsorption/desorption isotherms, as well as Fourier transform infrared, diffuse reflectance, ultraviolet–visible absorption, and photoluminescence (PL) emission spectra. Pure ZnO and 12 S-containing ZnO nanoparticles were examined as photocatalysts for the degradation of the rhodamine B (RhB) contaminant. Among the S-containing samples, 0.10 g of the sample doped with 0.5 wt % S could degrade 100% of RhB (5 ppm) at pH = 5 in 90 min. It was also found that the 0.8 and 1.1 wt % S-doped ZnO samples could degrade 99 and 97% of RhB in 150 min, respectively. The photocatalytic property of the 0.5 wt % S-doped ZnO was improved by adding a small quantity of ammonium persulfate…

Abstract Anthropogenic emissions of CO2 from industrial processes are considered the major cause of global warming and ocean acidification. To this end, different abatement strategies have been sought to capture CO2 directly from various effluent sources. Carbon capture and sequestration (CCS) has been touted to solve this problem; however, due to the challenges associated with this approach, research efforts have been focused on the development of dual-function materials (DFMs) that can effectively capture and convert CO2 to value-added products. In this review, we first describe existent CO2 capture processes, followed by relevant CO2 adsorbents. Then, we focus on the development of DFMs for CO2 capture and conversion through various reaction pathways, such as methanation, reverse water-gas shift, and dry reforming. We also elaborate on the challenges associated with these systems with emphasis on the stability and regenerability of the materials. Finally, some future perspectives and possible areas of study are highlighted.

With excellent comprehensive properties, polylactic acid/poly(butylene adipate- co -butylene terephthalate) (PLA/PBAT) blends have found wide applications as degradable materials. During the processing procedure, a third component compatibilizer is introduced to improve the compatibility and mechanical properties of PLA/PBAT blends. In this work, environmentally friendly epoxidized soybean oil (ESO) is used for the compatibilization of PLA/PBAT blends through the chemical reaction of ESO with terminated hydroxyl groups of the two phases. Through the adjustment of the amounts of ESO, the compatibilization effect on the properties of PLA/PBAT blends is studied. The compatibilization mechanism of ESO was analyzed by Fourier transform infrared spectroscopy and differential scanning calorimetry testing, and the results prove that ESO could react with PLA and PBAT to form a chemical bonding interface. The PLA/PBAT blends compatibilized with ESO demonstrated a significant increase in tensile strength, elongation at break, and notched impact strength.

Recently, transition metal/metal oxides (TMMOs) decorated on porous carbons (PCs) have been intensively focused on designing rational electrode materials for the promising future specific category of electrochemical energy storage and conversion technologies. In particular, TMMO incorporation with PC structures has become very attractive in the area of supercapacitors (SCs) mainly caused by their large accessible surface areas (SSA), together with the suitable pore size distributions (PSD), high electrical conductivity, and rapid redox reactions reversibly on the surface. The transportation of ions, as well as electrons in the bulk of electrodes, is fast as a result of optimal contact between electrodes and electrolytes at the electrode–electrolyte interface, thereby generating high specific capacities ( C sp ) of these PCs with TMMOs. We report a survey regarding recent advances in the fabrication and synthesis of TMMOs decorated on PCs with some physical characteristics and their applications for electrochemical capacitors. Some future trends and prospects for further development…

Frequent oil spill accidents and leakage of organic solvent destroy aquatic ecosystems and threaten marine lives. Separation of the oily pollutant from water with material has long been treated as an effective and environmentally friendly solution. As a result, great efforts have been made to construct a material with high oil adsorption capacity, high oil–water separation efficiency, high oil–water selectivity, and superior recyclability. Surface chemical composition and surface topography are two key factors that determine the surface wettability and oil–water separation efficiency of a material. In this review, we summarize the popular oil–water separation materials during the past five years, including adsorption material, filtration material, and smart controllable special wettable separation material. Before that, a basic theory of surface specific wettability is introduced. The perspectives and challenges of each material are also highlighted.

Carbon quantum dots (CQDs), as a novel fluorescent carbon nanomaterial, have raised worldwide concern on account of their remarkable biocompatibility, water solubility, chemical stability, nontoxicity, high conductivity, and turntable photoluminescence properties. Research on CQDs has been implemented for a dozen years, involving numerous precursors, synthesis methods, properties, and applications. Among them, the conversion of biomass waste into value-added CQDs has been considered as a green synthesis route for CQDs fabrication owing to its low cost, sustainability, environmental friendliness, and commercialization. This review focuses on the promising biomass-derived CQDs, including their advanced synthesis strategy, formation mechanism, modification technology, and application. The innovative up–down joint technique shows great potential in large-scale production of biomass-derived CQDs. The modification technology (size and shape control, heteroatom doping, surface passivation, composites) enables the tuning of their properties for high-quality products. It hopes to provide a…

To solve the coating’s defects and achieve the goal of lightweight heavy-duty anticorrosive coatings, various two-dimensional (2D) nanomaterials are introduced to polymeric coatings to prepare long-term high-performance anticorrosive coatings. In this review, we concluded overall design ideas of the composite corrosion-resistant polymer coatings for a wide range of 2D nanomaterials and typically reviewed the development of graphene, boron nitride (BN), molybdenum disulfide (MoS 2 ), zirconium phosphate (ZrP), MXene (Ti 3 C 2 T x ), and binary hybrid nanosheets (0D/2D, 1D/2D, 2D/2D, 3D/2D) in polymeric anticorrosive coatings. Finally, based on the above discussion, the challenges and outlooks in this promising field are featured from the perspective of chemical engineering.

A screen-printed electrochemical sensor based on Fe 3 O 4 @cellulose nanocrystals/Cu nanocomposite (Fe 3 O 4 @CNC/Cu) has been constructed for the sensitive detection of venlafaxine. The magnetic Fe 3 O 4 @cellulose nanocrystal/Cu nanocomposite was prepared by a green procedure using a plant extract ( Petasites hybridus leaf) as a stabilizing and reducing agent for copper. The formation of Fe 3 O 4 @CNC/Cu was validated through X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, ultraviolet–visible spectral analysis, vibrating sample magnetometer, and thermal analysis. Fe 3 O 4 @CNC/Cu was next used for modifying a graphite screen-printed electrode, intended for the analysis of venlafaxine concentration. The electrochemical behavior of venlafaxine on the resulting electrode was evaluated through cyclic and differential pulse voltammetry and chronoamperometry. The tests indicated that the sensor has good performance for the electrochemical detection of…

Abstract This work presents the development of molecular-based mathematical models for the prediction of electrical conductivity of deep eutectic solvents (DESs). Two new quantitative structure–property relationship (QSPR) models based on conductor-like screening model for real solvent (COSMO-RS) molecular charge density distributions (Sσ-profiles) were developed using the data obtained from the literature. The data comprise 236 experimental electrical conductivity measurements for 21 ammonium- and phosphonium-based DESs, covering a wide range of temperatures and molar ratios. First, the hydrogen-bond acceptors (HBAs) and hydrogen-bond donors (HBDs) of each DES were successfully modeled using COSMO-RS. Then, the calculated Sσ-profiles were used as molecular descriptors. The relation between the conductivity and the descriptors in both models has been expressed via multiple linear regression. The first model accounted for the structure of the HBA, the HBD, the molar ratio, and temperature, whereas the second model additionally incorporated the interactions between the molecular…

Abstract 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 second 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.

Among the various problems the world is facing, two problems are addressed in this paper. On the one hand, biomass, the fourth largest and most important renewable energy option that can provide different forms of energy, is criticized because it competes, sometimes, with the food chain. On the other hand, the amount of municipal sewage sludge has continued to increase over the years, and its disposal remains a crucial point of discussion between urban planners, wastewater managers, and leaders of environmental protection. To address this problem, researchers are directing their focus toward alternatives to conventional biomass resources, such as organic wastes and residues. Thus, municipal sewage sludge is a likely candidate for energy and high-value added material production. Regarding this issue, one of the main methods proposed by researchers is the pyrolysis process. The aim of this paper is to review the research conducted on sewage sludge conversion through the pyrolysis process. After characterizing municipal sewage sludge, we present a summary of the sewage sludge pyrolysis…

In an integrated biomass conversion process, pretreatment becomes an indispensable unit operation to enhance the accessibilities of cellulose and hemicelluloses for producing biofuels or chemicals. Besides carbohydrates utilization, lignin valorization is also considered as a key of achieving economic viability of biorefineries. The pretreatments using alkaline reagents exhibit a superior performance on boosting the yield of fermentable sugars by separating the lignin fraction and altering lignin structures and properties, offering the potential to facilitate the covalorization of lignin and carbohydrates. The diverse lignin recovered from alkali-based pretreatment affects the subsequent lignin depolymerization and conversion process due to the varying chemical and physical properties. In this review, the features and performances of different types of alkali-based pretreatments in the modifications to lignin are discussed. Also, the drill-down analysis of the promising methods to depolymerize lignin provides deep insights toward the conversion and upgrading of lignin isolated from…

Even though the performances of CO 2 adsorbent materials for temperature swing adsorption (TSA) are typically assessed based on the equilibrium adsorption capacity, the actual feasibility of a sorbent in real applications cannot be reliably inferred from only this parameter. Indeed, more than the maximum CO 2 uptake achievable at equilibrium, it is necessary to know the real quantity of CO 2 that can be captured in a complete adsorption/desorption cycle, namely, the difference between the quantity of CO 2 adsorbed under adsorption and desorption conditions, which is defined as the CO 2 working capacity. In this work, dynamic breakthrough and regeneration tests have been performed using a fine porous activated carbon in a lab-scale TSA sound-assisted fluidized-bed rig to experimentally evaluate the CO 2 working capacity. In particular, the standard sound-assisted fluidized-bed TSA cycle has been modified by applying the heating and purging (H&P) strategy to increase the cycle performances with regard to the CO 2 purity and recovery. Then, the effect of adsorption/desorption…

Three factors, (i) the ethanol “blend wall”, which limits its market as a transportation fuel, (ii) advances in production efficiency, and (iii) feedstock diversification, could lead to excess ethanol at competitive prices. Those factors have already motivated a search for value-added derivatives (e.g., distillate fuels, olefins, and asymmetric amines). Siting small, low cost, flexible conversion facilities to process ethanol at or near the fermentation plant could encourage the growth of an enterprise. Decreasing the barriers to entry, matching supply and demand, and enhancing access to production incentives are enabling success factors. This review discusses the process chemistries that might be employed by such ethanol conversion facilities based on market prices. Then, we describe how these technologies might benefit from process intensification to simplify the processing and to avoid large pressures or large temperature gradients typically employed in conventional, large scale facilities.

Production of protective textiles against solar radiation and microbial pathogens has been progressively considered in the area of the textile industry to rescue the human health. In this regard, herein, a novel technique for the preparation of multifunctional textiles via incorporation of silicate and zeolitic imidazole frameworks (ZIFs) has been systematically studied. ZIF(Ni), ZIF-8(Zn), and ZIF-67(Co) as three different ZIFs were formed directly within the cotton fabrics before and after silicate modification. Due to their cross-linking effect, insertion of silicate first increased the amount of adsorbed MOF onto fabrics from 101.8–108.6 to 141.6–149.1 mg/g. The direct formation of ZIF within cotton fabrics was confirmed by electron microscopy, X-ray diffraction, and infrared spectra. After modification with ZIF(Ni) and ZIF-67(Co), the cotton fabrics gained brown and purple decorative colors, respectively, with good fastness properties. Modification of cotton fabrics with silicate followed by ZIF(Ni) showed excellent UV protection (UPF = 47) and lowered to very good protection…

High Resolution Image Download MS PowerPoint Slide In liquid–solid adsorption, fluid film diffusion is typically faster than intraparticle diffusion, especially for microporous adsorbents. However, fluid film diffusion might play a significant role in the overall rate of the process for mesoporous–macroporous and non-porous solids. In most adsorption modeling studies, the fluid film diffusion step is typically ignored, which is not always justified. This article critically discusses the theory behind the liquid–solid mass-transfer coefficient in stirred vessels and presents the dissolution and adsorption methods adopted for estimating its value. Then, starting from the definition of the Biot number, an original analysis is developed with reference to selected studies. Surface versus pore diffusion of the adsorbate in the adsorbent is taken into account, and external versus internal mass-transfer resistance is considered to put the fluid film resistance back in the picture when needed. Iso-Biot charts where the operating points can be visualized are presented as well.

Formic acid is a liquid, safe, and energy-dense carrier for fuel cells. Above all, it can be sustainably produced from the electroreduction of CO 2 . The formic acid market is currently saturated, and it requires alternative applications to justify additional production capacity. Fuel cell technologies offer a chance to expand it, while creating an opportunity for sustainability in the energy sector. Formic acid-based fuel cells represent a promising energy supply system in terms of high theoretical open-circuit voltage (1.48 V). Compared to common fuel cells running on H 2 (e.g., proton-exchange membrane fuel cells), formic acid has a lower storage cost and is safer. This review focuses on the sustainable production of formic acid from CO 2 and on the detailed analysis of commercial examples of formic acid-based fuel cells, in particular direct formic acid fuel cell stacks. Designs described in the literature are mostly at the laboratory scale, still, with 301 W as the maximum power output achieved. These case studies are fundamental for the scale-up; however, additional efforts…

In this work, manganese well-dispersed on Fe 3 O 4 microsphere (Mn–Fe 3 O 4 ) catalyst was synthesized. It exhibited excellent catalytic performance for the direct conversion of carbon dioxide (CO 2 ) into light olefins. A CO 2 conversion of 44.7% with high selectivity of light olefin (46.2%, yield of 18.7%), high O/P ratio (6.5), and low selectivity of CO (9.4%) was obtained over the 10Mn–Fe 3 O 4 catalyst. The Mn–Fe 3 O 4 catalyst was studied by XRD, SEM, (HR)TEM, STEM–EDS, H 2 -TPR, and CO 2 -TPD. The result indicated that the manganese promoter could facilitate the adsorption of CO 2 and the activation of C═O bonds as well as inhibit the secondary hydrogenation. This work offered a novel Fe-based catalyst system to the utilization of CO 2 and an understanding in promoting C═O bond activation in the first step of CO 2 hydrogenation to hydrocarbon reaction.

Optimization in chemical engineering often involves two or more objectives, which are conflicting. Multiobjective optimization (MOO) generates a set of equally good solutions from the perspective of objectives used; these solutions are known as nondominated or Pareto-optimal solutions. Although MOO has become popular in chemical engineering in the past 20 years, majority of studies are limited to finding Pareto-optimal solutions and only some papers discussed the selection of one nondominated solution for implementation. Thus, the main research gap in the application of MOO in chemical engineering is the very limited use of selection or ranking methods. To address this gap, 8 weighting methods and 4 more selection methods (besides 10 methods analyzed by Wang and Rangaiah) are carefully chosen and implemented in an MS Excel-based program. Then, all these methods are applied to 12 mathematical and 13 chemical engineering problems. The results of this extensive analysis indicate that the entropy method, criteria importance through intercriteria correlation method, and best–worst method…

There has been a growing interest in advanced technology that transforms biomass-derived feedstock into renewable chemicals. Hydrothermal liquefaction (HTL) of lignin into low-molecular-weight fragments (e.g., monomer, dimer, and oligomer), and subsequent catalyzed transformations, offer the promise of unlocking diverse aromatic products. In consideration of the diversity of lignin feedstocks, we shed light on the impact of variations in lignin structure on the conversion efficiency. This review aims to present the latest advances in the HTL of lignin and highlights key factors (reaction solvent, temperature, catalysts, and in particular lignin types) in reductive/oxidative processes by evaluating the yield of aromatic monomers and the selectivity of target products. The mechanistic studies based on lignin model compounds were summarized to provide deep understanding of the reaction pathways to prove the crucial roles of lignin structures and high-performance catalysts in controlling catalytic activity. Finally, we emphasize that advances in emerging HTL technology, catalyst design,…

In this work, a highly efficient flame retardant and electromagnetic interference (EMI) shielding coating on cotton fabric was fabricated by a simple solution impregnation and dip-coating method, which involved three layers of polyacetimidate (PEI), ammonium polyphosphate (APP), and Ti 3 C 2 T x . When exposed directly to flame, the PEI/APP coating lead to a char layer resulting in self-extinguishing performance. Particularly, the cotton fabric coated by increasing amounts of Ti 3 C 2 T x gradually achieved EMI shielding performance. When the Ti 3 C 2 T x sheets content was 5.2 mg/cm 2, a high electrical conductivity of 670.3 S·m –1 and a EMI shielding effectiveness of 31.04 dB were achieved in the X-band with an absorption-dominated mechanism. Besides, such modified cotton fabric also has the potential to be used as an electrical heating material. The temperature could even reach up to about 64.3 °C under an applied voltage of just 4 V. Therefore, this work provided a feasible idea for preparing multifunctional fabrics.

Methanol synthesis from CO 2 hydrogenation at high temperatures was investigated over ZnO x /ZrO 2 catalysts to illustrate the role of calcination temperatures (600–1000 °C) of the ZrO 2 support. Characterization results revealed that a ZnO x /ZrO 2 solid solution (Zn–O–Zr) was formed for all catalysts. The formation of the ZnO x /ZrO 2 solid solution was related to an enhancement of weak CO 2 adsorption. The ZnZr catalyst with the ZrO 2 calcined at 600 °C achieved the highest methanol selectivity (75.1%) at 300 °C, corresponding to the highest amount of weak basic sites. However, its methanol selectivity drastically declined as the reaction temperatures increased because the weakly adsorbed CO 2 could not be stabilized for hydrogenation to form methanol. A substantial reduction of weak basic sites was observed with ascending calcination temperature of ZrO 2, enhancing methanol selectivity at elevated temperatures.

We describe the current status of our research on, and the development of, the Electrochemically Mediated Amine Regeneration (EMAR) process for the capture of CO 2 from flue gases. The absorption step in the EMAR process is the same as in the widely used amine process, but the desorption step is accomplished electrochemically as opposed to by a thermal swing used in the amine process. Our laboratory unit has operated continuously for over 200 h, spanning 130 absorption/desorption cycles. We have established an understanding of the thermodynamics of the EMAR process and provided engineering estimates of key features (energetics and sizing) of this technology. The EMAR system does not rely on steam integration, making it a truly plug-and-play unit that can be easily deployed for a range of applications. The EMAR system can also be scaled-down for distributed, modular, and small-scale operations (e.g., stainless steel mini-mills, etc.). Results to date indicate that the EMAR process has the potential to be a viable option for post-combustion CO 2 capture.

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 nanoparticle (NP)-deposited 2D Ti 3 C 2 T x MXenes were prepared by an 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 an 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 Ti 3 C 2 T x MXene supports.

Abstract The capture and concentration of CO2 from a dry ambient air stream by temperature vacuum swing adsorption (TVSA) have been experimentally demonstrated on a small scale by using a single bed system packed with 20 g of zeolite X. Initially seven different commercially available type X zeolites were investigated, and one of them was chosen for a more comprehensive study. Breakthrough experiments were carried out by perturbing the He saturated bed with compressed ambient air with CO2 of around 410–440 ppm. In the process studied, a basic four-step TVSA cycle was investigated first, comprising the following steps: pressurization, adsorption, blowdown, and desorption. Four different regeneration temperatures were tested along with four different gas space velocities. With this cycle configuration, CO2 was concentrated to 95% from 400 ppm with total capture fractions as high as 81%. The energy consumption per ton of CO2 captured in the system is discussed for the different process configurations. The results from this study are discussed on how to improve the possibility of using…

The methods to provide functions to nanofiber webs and applications, characterization, evaluation methods, market value, and future directions of nanofiber webs are summarized and presented in this review. Incorporating drugs, nanoparticles, functional matters, or arranging special surface structures are customarily used methods to furnish the performance of nanofibers. The promising application areas of nanofiber webs include drug delivery, water filtration, biomedical application, energy storage protective clothing, and air/gas filtration. The characterization of nanofiber webs includes general and functional properties. The market values of nanofiber products are summarized and analyzed based on the reports conducted by BBC Research.

The biodiesel obtained from nonedible and waste-cooking oils through the transesterification process has been recognized as a renewable energy source. This transesterification process produces glycerol as the main byproduct. Glycerol and its derivatives have a lot of applications in the pharmaceutical industry, organic synthesis, and the cosmetic industry. The glycerol can be converted into value-added derivatives via several catalyzed chemical reactions, viz. esterification, selective reduction, selective oxidation, pyrolysis, halogenation, condensation, carboxylation, dehydration, reformation, transesterification, etherification, etc. Among various glycerol derivatives, glycerol carbonate is one of the most value-added products which is employed in industrial application for the preparation of polyurethanes. There are several methods for its preparation using glycerol as a platform molecule, but the transesterification method using dimethyl carbonate is the most efficient way employing mild reaction conditions and the least harmful reagents. This review presents a critical…

In this work, porous carbons were achieved from sustainable biomass lotus stalk. Unlike the common carbonization-activation two-step method, a facile one-step KOH activation procedure was explored to make the carbonaceous sorbents. The as-made adsorbents have advanced porous structures and hold superior CO 2 uptake, up to 3.68 and 5.11 mmol/g at 1 bar, 25 and 0 °C, respectively. After carefully checking the relationship of CO 2 uptake with each porous characteristic, the volume of narrow micropores is found to be the leading factor that determines the CO 2 adsorption abilities of the adsorbents under ambient conditions. Moreover, the narrower pore size distribution is also preferential to the adsorption of CO 2 . Apart from the high CO 2 uptake, these lotus stalk-derived adsorbents also possess extra excellent CO 2 capture properties such as good recyclability, fast adsorption kinetics, reasonable CO 2 /N 2 selectivity, suitable heat of adsorption, and high dynamic adsorption capacity. These results demonstrate that these cost-effective carbonaceous adsorbents developed by the…

Dye containing industrial effluent streams are a cause of major environmental concerns, especially those which are not easily biodegradable. Many techniques have been developed to remove dyes from the waste stream; however, most of them suffer from a weakness of efficiency and effectiveness when an attempt is made for industrial implementation. A recently developed dye removal method using surfactants offers the benefits of high removal efficiency, ease of waste disposal, scope of efficient recovery, and the use of nontoxic and less harmful reagents. This review aims to contribute to this growing area by summarizing the mechanisms of dye–surfactant interactions and investigating the influence of different process parameters such as pH, concentration of surfactants, dyes, and electrolytes, temperature, etc. on the efficiency of the method. The review also attempts to present future research scopes of these techniques with a critical analysis of industrial applicability.

Nanocellulosic materials, either as cellulose nanofibrils (CNF) or cellulose nanocrystals (CNC), have a wide range of potential applications in different industrial sectors, due to their renewable nature and remarkable properties. Here, a sustainable and environmentally friendly method to obtain nanocellulose was evaluated using hydrolysis with citric acid, an organic acid that can be obtained as a biorefinery product. This approach resulted in a single-step extraction of nanocellulose, with carboxyl functionalization of the surface varying according to hydrolysis reaction times from 1.5 to 6 h, at 120 °C, as evidenced using NMR to measure the degree of substitution. The charged surface groups of CNC and CNF resulted in improved colloidal stability, with ζ-potential values from −36 to −48 mV. Both CNC and CNF extracted using different reaction times were thermally stable, but the increase of carboxyl groups reduced the degradation temperature. Techno-economic analysis (TEA) showed that the cost of citric acid had the greatest influence on the minimum product selling price (MPSP) of…

Nanofiltration (NF) membranes, especially polyamide (PA) ones, are widely applied in water treatment, food processing, and resource recovery thanks to their excellent separation selectivity to small solutes and high water permeability. However, membrane fouling is inevitable during the long-term operation and limits the large-scale applications of NF technology. Chemical cleaning is considered the most effective way to avoid fouling aggravation and quickly restore membrane permeability on site. However, frequent chemical cleaning would cause reversible/irreversible changes in the physical and chemical properties of NF membranes, resulting in membrane damage and deterioration of separation performance. Moreover, the PA NF membrane with high selectivity and a relatively low cross-linking degree is more sensitive to chemical cleaning. Many efforts, therefore, have been dedicated to clarifying the effect of chemical cleaning on the NF membrane properties and its separation performance. This review summarizes recent developments in the field and epitomizes the synergistic/inhibitory…

Herein, we demonstrate the synthesis of ammonia via atmospheric dielectric barrier discharge (DBD) plasma discharge over zeolite 5A. The presence of the zeolite in the DBD reactor promoted the formation of microdischarges and a change of the voltage–current characteristics of the reactor, leading to an enhanced catalytic performance. The perturbation of the zeolite surface electronic properties due to atmospheric plasma led to an enhanced reactive state at the zeolite surface which promoted the dissociation of nitrogen and the subsequent formation of ammonia. An energy yield of 15.5 g-NH 3 /kW h was observed at an equimolar N 2 to H 2 ratio in the presence of zeolite 5A, which is at least 50 times higher than that obtained in the absence of the zeolite.

Calcination plays an important role in obtaining high-performance catalysts for heterogeneous reactions. In this work, the effect of calcination temperature on the performance of the Ni@SiO 2 catalyst in the methane dry reforming reaction was investigated. The calcination temperature from 823 to 1223 K led to different sizes of Ni nanoparticles and strengths of metal–support interactions in the catalysts, which consequently affected the performance of the reforming reaction. The highest performance was neither achieved over Ni@SiO 2 - T ( T = 823 and 923 K) catalysts with small Ni sizes and weak metal–support interactions nor gained over Ni@SiO 2 - T ( T = 1123 and 1223 K) catalysts with big Ni sizes and strong metal–support interactions, while it was obtained over the Ni@SiO 2 -1023 catalyst with intermediate Ni size and intermediate metal–support interactions. The volcanic relationship between the catalytic performance and catalyst calcination temperature was assigned to both the Ni size effect and metal–support interaction that their combination significantly influenced the…

Here, we report a simple hydrothermal method and in situ calcination to synthesize ZnO/K-CN x heterostructure nanocomposites. The optimized ZnO/K-CN 0.5 exhibits excellent photocatalytic degradation and adsorption efficiency of tetracycline under simulated sunlight, and the degradation rate reaches 90% (the adsorption removal rate is 50%). Moreover, ZnO/K-CN 0.5 also has high stability and recyclability. The excellent photocatalytic activity can be attributed to the following factors. (1) The K-doped exfoliated g-C 3 N 4 nanosheet (K-CN) and the ZnO nanorod form a unique type-II heterojunction that promotes the separation of photogenerated carriers and provides very short photogenerated carrier diffusion distances. (2) The surface ζ-potential can enhance the adsorption capacity of tetracycline through electrostatic attraction and repulsion, resulting in synergistic effects of photocatalysis and adsorption. This work highlights the important role of integrating doping and exfoliation techniques into type-II heterojunctions to form nanocomposite photocatalyst materials, which have…

Electrolyte additives for lithium-ion battery (LIB), commonly categorized into anode additives, cathode additives, redox shuttle additives, and fire retardants, can improve properties of electrolytes and provide protection of electrodes and battery operations. Redox potentials are major properties that influence the performance and applications of the additives. In this study, we develop Gaussian process regression models to predict redox potentials of electrolyte additives for LIBs from molecular structural features of electrolyte additives. The models are simple and fast to implement, produce predictions with low root mean squared errors, and thus might be considered as efficient alternatives to the DFT approach for estimations of redox potentials. The Gaussian process regression models also provide statistical correlations between the molecule structure and redox potential.

Stochastic modeling techniques have emerged as a powerful tool to study the time evolution of processes in many research fields including (bio)chemical engineering and biology. One of the most applied techniques is kinetic Monte Carlo (kMC) modeling according to the stochastic simulation algorithm (SSA) as pioneered by Gillespie, in which MC channels and time steps are discretely sampled from probability distributions. In the last decades, the SSA algorithm, as originally developed for systems with elemental species (e.g., A, B, C, etc.), has been further adapted (i) to also tackle systems with distributed species, therefore, populations and (ii) to enable faster algorithm execution. In the present contribution, we highlight the most important developments, taking bulk/solution polymerization as the reference distributed chemical process. We address SSA principles based on conventional array data structures, common acceleration methods (e.g., τ leaping and the scaling method), and the strength of tree- and matrix-based data structures for detailed storage of molecular information…

The aim of this work was to develop a superadsorbent for the removal of Hg 2+ ions from aqueous solutions. In this regard, a porous covalent triazine ring-based nanoneedle was synthesized through a facile hydrothermal method. The structure and morphology of the synthesized covalent triazine ring-based adsorbent were characterized by different techniques. The structural stability of the synthesized superadsorbent was examined under different temperatures and pH conditions. The maximum adsorption capacity of the prepared organic framework is 1826 mg g –1 for removing Hg 2+ ions at ambient temperature and an optimum pH of 5. Different linear and nonlinear models were applied for the fitting of the obtained adsorption data. It was found that the adsorption data can be well fitted to the linear Langmuir model ( R 2 = 0.998). The adsorption kinetics can also be well described by the linear pseudo-second-order model. To make a portable, highly sensitive, and low-cost device for in situ sensing of trace amounts of Hg 2+ ions, the smartphone colorimeter platform was developed using…

Recently, owing to their excellent structural and transport properties, two-dimensional membranes have attracted tremendous interest for their potential application in molecular separation. In this work, a new type of functionalized Ti 2 CT x MXene membrane was proposed by introducing different kinds of polyelectrolytes to regulate the membrane physicochemical structure for pervaporation dehydration of isopropanol dehydration. The morphology, physical, and chemical properties of powders and MXene-based membranes were studied by SEM, AFM, FTIR, XPS, and contact angle test. Meanwhile, the effect of polyelectrolyte functionalization on the MXene membrane performance for isopropanol dehydration was also studied. The results showed that the poly(diallyldimethylammonium chloride) (PDDA) functionalized MXene membrane possesses the highest separation performance owing to the optimized electrostatic effect and hydrophilicity. Besides, other influencing factors including PDDA concentration, MXene loading, and operating conditions on the MXene membrane performance were also systematically…

Secondary nucleation can bring the crystallization process into a more easily controlled state, and it is playing an important role in controlling crystal size distribution, polymorphism, and chirality of the crystal products, no matter whether in a batch or continuous crystallizer. Therefore, in this review, we revisit the research of secondary nucleation in the past 30 years to understand the fundamentals and application of secondary nucleation. First, we summarize the sources of secondary nuclei, that is, how secondary nucleation occurs. Then, we discuss the secondary nucleation threshold from the perspective of the metastable zone widths which are associated with the nucleation mechanism. Furthermore, we discuss how to employ secondary nucleation to regulate the properties of crystalline products (particle size distribution, crystal polymorphism, chirality, etc.). More importantly, we also discuss how polymorphism and chirality can act as a probe to explore the origin of secondary nucleation. Finally, we give conclusions and outlooks, mainly on the molecular nucleation mechanism…

Epoxy resins are widely used in various applications including electronic materials, automobiles, adhesives and coatings, and fiber-reinforced composites because of their unique properties. Additive manufacturing has advantages over conventional manufacturing techniques: simplicity of printing complex structures, fast production, and freedom of design. It follows the footprint of digitalization and the 4.0 industry. Additive manufacturing of epoxy resin is the latest trend, which replaces conventional materials and methods in different fields because of the ability to manufacture complex geometries quickly and at low cost. This review pays attention to pristine and latest advances in additive manufacturing of epoxy resins and presents the historical origins and evolution of each related printing technique. The main technical aspects, including the curing of epoxy resins, suitable types of resins, the role of curing agents, photoinitiators, and properties of epoxy parts, are discussed in detail. The survey on representative latest trends is presented.

In the last 5 years, reductive catalytic fractionation of lignocellulose biomass has emerged as a promising biorefinery concept that combines biomass fractionation with the preservation of chemical functionality in its products. Although significant efforts have been made in optimizing this technology on lab scale, the implementation on a larger (pilot) scale is still in its infancy. In our own search for the scale-up potential of this technology, we faced several fundamental and technical research questions that, to this day, remain unanswered. These fundamental questions are related to four main aspects of RCF, the lignocellulose feedstock, the operating pressure, the redox catalyst, and the solvent. In order to inspire future multidisciplinary research in the RCF community, these scale-up challenges are presented and discussed via multiple angles combining chemical process hurdles with more technical aspects, such as reactor design and process consequences.

Abstract Superhydrophobic materials are found in a suite of scientific and industrial applications, and given their broad potential use, there is great interest in facilitating their mass production. Although numerous methods have been used to produce superhydrophobic materials, only a few are capable of fabricating superhydrophobic surfaces and materials at an industrial scale. Techniques such as injection molding, compression molding, hot embossing, and polymer casting play an important role in the mass production of superhydrophobic polymer surfaces. This technical literature review summarizes recent advances in the polymer molding processes used to fabricate superhydrophobic materials. Here, we review replication methods and the materials that can be used by these approaches. We also evaluate the advantages and disadvantages of these methods and discuss the challenges of molding and demolding single-level structures (e.g., microstructures and nanostructures) and multilevel structures (e.g., micro-nanostructures, micro-microstructures, and micromicro-nanostructures), with a focus…

With the increasingly strict diesel standards in the countries of the world, deep processing of diesel oil to ultralow sulfur levels is receiving more and more attention. This paper mainly reviews the reaction mechanism, catalysts, and process conditions of diesel hydrodesulfurization, and it provides new research directions for producing ultralow sulfur diesel (ULSD). In terms of mechanism, the sterically hindered sulfides, nitrides, aromatic compounds, and hydrogen sulfide affect the direct desulfurization and hydrogenate pathways of the hydrodesulfurization reaction to varying degrees. In order to eliminate these effects, the properties of high-dispersion active metals, large pore size, high specific surface area, high content of medium-weak acid, and a certain amount of Bronsted acid support are beneficial to further improve the activity of the catalyst, to produce ULSD that meets market demand. This article also reviews the influences of process conditions (for instance, temperature, hydrogen pressure, liquid hourly space velocity, and hydrogen consumption) on the diesel…

Natural biomass is a promising candidate for the preparation of heteroatom-doped carbons that can be used as effective electrode catalysts for microbial fuel cells (MFCs), due to its intriguing features, such as high abundance, rich heteroatom contents, and low cost. In this review, we summarize recent process in the design and fabrication of MFC electrodes based on biocarbons; discuss the effects of preparation methods, bacteria/electrode interaction, pore structure, and assembly procedure on the electrode and cell performance; and conclude with a perspective highlighting the strategies and critical challenges in electrode fabrication for further enhancement of the device performance.

The increase in the synthesis of biodiesel has also contributed to a surplus of crude glycerol, which is a significant bottleneck throughout the supply chain of biodiesel and has produced new problems for its sustainable usage. While there is a broad variety of possible uses of crude glycerol, it is restricted by its purity level, affecting its physical, chemical, and biological properties. In this Review, we look at optimization of the biodiesel production process and significant rise in the use of glycerol. The conversion of impure glycerol into pure glycerol and potential application of glycerol in value-added products are emerging topics. The acetalization of glycerol with acetone in the presence of various heterogeneous catalysts and production of solketal—a valuable green product—are discussed. The research studies described herein mainly focus on innovative and emerging technology for sustainable solketal production, as well as the impact of reaction parameters, removal of water, and catalytic activity in both batch and continuous processes. Globally, the potential prospects…

Natural gas is one of the critical fossil fuel sources in the world to fulfill current energy demand in the global market. Methane is the primary component in natural gas and its concentration is dependent on the source; a variety of impurities, such as nitrogen, carbon dioxide, oxygen, helium, hydrogen sulfide, water, and heavier hydrocarbons can be present, which reduces the overall fuel quality. Purification of natural gas is important in order to meet the U.S. pipeline and minimum heating value specifications. The separation of nitrogen from methane is challenging because of their similar molecular size (i.e., the two gases differ in kinetic diameter by only 0.16 Å). This Review discusses different methods for separating nitrogen from methane. Of these methods, pressure swing adsorption is one of the most effective techniques for separating nitrogen from natural gas using porous adsorbents, and encouraging results have been demonstrated in the past few decades. Many types of porous adsorbents are discussed here, including carbon molecular sieves, activated carbons, zeolites,…

Olefins production plants are large-scale plants, in most of which gaseous and liquid hydrocarbons are cracked to produce light olefins. The complex and large-scale nature of these plants makes it an utmost necessity to design and operate them with the use of computer-aided optimization and control methods. This review paper provides an overview of the reported research works on the optimization and control of different parts of olefin plants. The main research studies are discussed in two main sections: Optimal Design and Process Operation and Control. In the Optimal Design section, the state of the optimal design of cracking furnace systems, cold-end separation systems, and separation columns have been studied. Then in the Process Operation and Control section, the control of cracking furnaces, the control of cold-end separation systems, real-time optimization of olefin plants, cyclic scheduling of cracking furnace systems, production planning of olefin plants, and finally, start-up and shutdown operations in these plants have been extensively reviewed. This paper is a…

The integration of conductive carbon supports with organic phase-change materials (PCMs) enables the development of energy conversion and thermal energy storage systems. Herein, we propose a facile strategy for preparing electro- and photo-driven form-stable PCM composites by loading paraffin wax (PW) into a biomass-derived three-dimensional carbon scaffold. The biomass, raw cotton, was transformed into a hollow carbon fiber (HCF) scaffold by alkaline treatment with subsequent pyrolysis. The resultant HCF scaffold encapsulated a high content of paraffin wax reaching up to 85%. The prepared composites exhibited uniform heat distribution and form-stable phase-change behavior with high energy storage density (up to 182.22 J g –1 ). Moreover, the graphitic character of interconnected HCFs provided thermally and electrically conductive pathways in the PCM matrix. As a result, the HCF-PW composite achieved outstanding energy conversion and storage efficiencies under low input voltage and light intensity. The results provide insightful progress in the utilization of biomass-derived…

Abstract Zirconium metal–organic framework (Zr-MOF) materials with excellent ion adsorption capacities and efficient ion sieving properties are highly desirable for many important industrial separation applications. There has been significant progress in the fabrication of Zr-MOF-based ion adsorbents and ion sieving membranes in recent years for efficient removal of toxic ions and/or recovery of precious metal ions from water. These Zr-MOF materials possess uniform pore sizes, high porosities, and specific functional groups for enhancing ion adsorption capacity, ion selectivity, and ion conductivity. Recent advances in the fabrication of advanced Zr-MOF-based ion adsorbents for removal of toxic cations and anions from water are summarized. Following this, recent achievements of high-quality Zr-MOF membranes/channels for efficient ion sieving are highlighted and discussed in detail. Finally, a summary and some perspectives of future developments and challenges in this exciting research field are presented.