Abstract: Data-based process monitoring has become a key technology in process industries for safety, quality, and operation efficiency enhancement. This paper provides a timely update review on this topic. First, the natures of different industrial processes are revealed with their data characteristics analyzed. Second, detailed terminologies of the data-based process monitoring method are illustrated. Third, based on each of the main data characteristics that exhibits in the process, a corresponding problem is defined and illustrated, with review conducted with detailed discussions on connection and comparison of different monitoring methods. Finally, the relevant research perspectives and several promising issues are highlighted for future work.

Abstract: A simple and facile one-pot synthesis of fluorescent carbon dots from orange waste peels was performed using the hydrothermal carbonization method at a mild temperature (180 °C). The chemical composition and morphological feature of the obtained carbon dots (C-dots) were characterized using various spectroscopies and a transmission electron microscopy. The prepared hydrothermal carbons were amorphous in nature, and clusters of polyaromatic hydrocarbons included a large quantity of oxygen functional groups. A composite of C-dot with ZnO was used as a photocatalyst for degradation of naphthol blue-black azo dye under UV irradiation, and the superior photocatalytic activity was demonstrated. Overall, the present preparation method of C-dots takes on meaning in the area of green synthesis in aqueous solutions, and the product has great potential as a component material in the development of a remarkably efficient catalytic system.

Abstract: In the present paper, we investigated CO2 capture with 24 tertiary amine absorbents, including three synthetic amines, with systematic modification of their chemical structures. Aqueous solutions of the amines (mass fraction 30%) were used to evaluate the performance for CO2 capture. Gas scrubbing, vapor–liquid equilibrium (VLE), and reaction calorimetry experiments were conducted in the laboratory to obtain the absorption rate, the amount of CO2 absorbed, cyclic CO2 capacity, and heat of reaction for each absorbent. The results for these absorbents were compared with the conventional tertiary absorbent N-methyldiethanolamine (MDEA). Seven of the investigated absorbents performed well with high absorption rates and cyclic capacities. Among these absorbents, some showed lower heats of reaction than MDEA. These results provide basic guidelines for discovery of potential tertiary amine-based absorbents that may lead to development of new absorbent systems in the CO2 capture area.

Abstract: This article is an up-to-date review of the literature available on the subject of ethanol to ethylene. The process of ethanol to ethylene has broad development prospects. Compared with the process of petroleum to ethylene, ethanol dehydration to ethylene is economically feasible. Researchers have been redirecting their interest to the ethylene production process, catalysts, and reaction mechanisms. A fluidized bed reactor, together with a wear-resistant, efficient, and stable catalyst will be the focus of future research that includes a deep understanding of the large-scale activated alumina catalyst and the molecular sieve catalyst used, and will promote the development of the ethanol dehydration to ethylene process and provide strong support for the market competiveness of the process.

Abstract: An in situ microwave-assisted synthesis approach has been developed to prepare N-TiO2/g-C3N4 composites using H2TiO3 as the reactant and NH3·H2O as the N-doping source. In this way, the N-TiO2/g-C3N4 composite catalysts have a porous structure and large surface areas, which increase the contact area of pollutants. Degradation of rhodamine B (Rh B) and methylene blue (MB) were carried out to evaluate the photocatalytic activity of samples under visible light irradiation. N-TiO2/g-C3N4 composite with 40 wt % N-TiO2 exhibits the highest photocatalytic activity and the optimal temperature is 400 °C. The increased photocatalytic activity of N-TiO2/g-C3N4 composites can be attributed to the formation of the heterojunction between N-TiO2 and g-C3N4, which suppresses the recombination of photoinduced electron–hole pairs. The tests of radical scavengers confirmed that •O2– was the main reactive species during the photocatalytic process.

Abstract: Ion-exchange membranes play an important role today in deionization of aqueous solutions, in electrochemical synthesis, and in energy conversion and storage. Some of the applications of ion-exchange membranes are mature and well established processes such as the water desalination by electrodialysis or the electrolytic chlorine–alkaline synthesis. Other applications of ion-exchange membranes are still in an early state of their development, such as the redox flow battery. In this publication the principles of state-of-the-art ion-exchange membrane processes and their applications are briefly described. Their advantages and limitations are discussed, and their commercial relevance is indicated. More recently developed products and processes are also addressed. Their basic functions are described, and their present and potential future applications are discussed. Research needs for a further improvement of ion-exchange membranes and their applications are pointed out.

Abstract: Polyprolylene is commonly used for crude oil spill cleaning, but it has low absorption capacity and is nonbiodegradable. In our work, a green, ultralight, and highly porous material was successfully prepared from paper waste cellulose fibers. The material was functionalized with methyltrimethoxysilane (MTMS) to enhance its hydrophobicity and oleophilicity. Water contact angles of 143 and 145° were obtained for the MTMS-coated recycled cellulose aerogel. The aerogel achieved high absorption capacities of 18.4, 18.5, and 20.5 g/g for three different crude oils at 25 °C, respectively. In the investigated temperature range of 10, 25, 40, and 60 °C for the absorption of the tested crude oil on the aerogel, a highest absorption capacity of 24.4 g/g was obtained. It was found that the viscosity of the crude oils is the main factor affecting their absorption onto the aerogel. The strong affinity of the MTMS-coated recycled cellulose aerogel to the oils makes the aerogel a good absorbent for crude oil spill cleaning.

Abstract: The conversion of lignocellulosic biomass for biofuels and biorefinery applications is limited due to the cost of pretreatment to separate or access the biomass’s three main usable components, cellulose, hemicellulose, and lignin. After pretreatment, each component may be utilized via chemical conversion, hydrolysis, and/or fermentation. In this review we aim first, to identify the current status-quo of knowledge of the parametric effects of ultrasound, second, to evaluate the potential of ultrasound as a pretreatment and fractionation method of lignocellulose, and last, to identify the challenges that this technology faces. Ultrasound produces chemical and physical effects which were both found to augment the pretreatment of lignocellulose via delignification and surface erosion. The magnitudes of these effects are altered when the ultrasonic field is influenced by parameters such as solvent, ultrasonic frequency, and reactor geometry and type. Therefore, the implementation of ultrasound for the pretreat...

Abstract: Activated carbon derived from finger citron residue (FAC) was tested as a new type of adsorbent for the removal of harmful dyes, namely, the anionic dye methyl orange (MO) and the cationic dye methylene blue (MB), from contaminated water. Liquid-phase adsorption experiments were conducted, and the maximum adsorption capacity was determined. Various conditions were evaluated, including initial dye concentration, adsorbent dosage, contact time, solution pH, and temperature. The Langmuir and Freundlich adsorption models were used to describe the equilibrium isotherm and to calculate the isotherm constants. It was found that the adsorption capacity of FAC is much higher than those of other types of activated carbons. Maximum equilibrium adsorption capacities of 934.58 and 581.40 mg/g for MO and MB, respectively, were achieved. Three simplified kinetic models, namely, pseudo-first-order, pseudo-second-order, and intraparticle diffusion equations, were used to investigate the adsorption process. The pseudo-seco...

Abstract: Although the basic principles of fibrous filters have been well understood for capture of micron and submicron sized particles, questions arise when they are applied to nanoscale particles. In the first part of this review, the classical theory of fibrous filters is described with focus on the principles that are applicable to nanoparticle collection. The areas of recent developments reviewed include thermal rebound of nanoparticles and the effects of particle shape, aggregate morphology, flow regime, humidity, fiber size, and particle loading. One of the outstanding questions in nanoparticle collection is the particle size at which the effect of thermal rebound on collection efficiency can be observed. Theoretical calculations indicate that the effect probably can be observed only for particles smaller than 1 nm, but experimental confirmation is difficult at present because of lack of instruments for classifying and counting subnanoscale particles. Two promising devices based on filtration principles hav...

Abstract: In recent years, the population explosion and environmental pollution have increased the interest of researchers in the discovery of new health and hygiene-related products for the well being of mankind. Among the possible approaches initiated by the textile industry, the use of low-environmental impact technologies- based on sustainable biopolymers- presents a novel possible avenue for large scale development of bioactive textiles. The purpose of this article is to review the information on the role of different biopolymers in the development of antimicrobial textiles. Increased sustainability, environment friendliness, reduced pollution, green chemistry, renewability and intrinsic biological activity are some of the attributes which make chitosan, cyclodextrin, sericin protein, and alginate suitable alternative agents for the functional finishing of textile materials. The application of biopolymers, along with the recent impact of various “green chemistry” strategies, on the antimicrobial properties of ...

Abstract: Liquefied natural gas (LNG) is attracting great interest as a clean energy alternative to other fossil fuels, mainly due to its ease of transport and low carbon dioxide emissions, a primary factor in air pollution and global warming. It is expected that this trend in the use of LNG will lead to steady increases in demand over the next few decades. To meet the growing demand for LNG, natural gas liquefaction plants have been constructed across the globe. Furthermore, single train capacity has been increased to strengthen price competitiveness. To achieve greater capacity, more complex refrigeration cycle designs that combine two or more different conventional single refrigeration cycles are being developed to obtain synergistic effects in the liquefaction process. At the same time, a variety of recent studies have focused on designing suitable processes for offshore and small-scale plants to improve the profitability of stranded gas fields. LNG plants are known to be energy/cost-intensive, as they require ...

Abstract: The inhibitive action of ethanol extract of Acalypha torta leaves (EAL) on corrosion of mild steel in 1 M HCl solution was investigated by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy, chronoamperometric measurements, and scanning electron microscopic observations. The adsorption of EAL on mild steel follows a Langmuir adsorption isotherm, and the activation parameters governing the adsorption process were calculated and discussed. Polarization measurements reveal that the EAL acts as a mixed-type inhibitor. The inhibition efficiencies obtained from weight loss measurements and electrochemical tests were in good agreement.

Abstract: In this study, we first report the development of a robust and efficient finite volume based adsorption process simulator, essential for rigorous optimization of a transient cyclic operation without resorting to any model reduction. We present a detailed algorithm for the common boundary conditions encountered in nonisothermal and nonisobaric adsorption process simulations. A comprehensive comparison of the high-resolution total variation diminishing (TVD) schemes, namely, van Leer and Superbee, with the weighted essentially nonoscillatory (WENO) finite volume scheme is performed, and trade-off plots are presented to identify the numerical scheme most suitable for attaining speed and accuracy at the same time. The simulator is then used to perform rigorous optimization of a four-step process for postcombustion CO2 capture from dry flue gas on zeolite 13X. The aim is to identify operating conditions at which the purity and recovery demands are met and to calculate corresponding energy consumption and proce...

Abstract: In the present investigation, three benzimidazole derivatives, namely, 4-(phenyl)-5-[(2-methyl-1H-benzimidazol-1-yl)methyl]-4H-1,2,4-triazole-3-thiol (Inh I), 4-(4-methylphenyl)-5-[(2-methyl-1H-benzimidazol-1-yl)methyl]-4H-1,2,4-triazole-3-thiol (Inh II), and 4-(4-methoxyphenyl)-5-[(2-methyl-1H-benzimidazol-1-yl)methyl]-4H-1,2,4-triazole-3-thiol (Inh III), were synthesized and investigated as inhibitors for mild steel corrosion in 15% HCl solution using the weight loss, electrochemical polarization, and electrochemical impedance spectroscopy (EIS) techniques. It was found that the inhibition efficiency of these inhibitors increased with increasing concentration. The effect of temperature on the corrosion rate was investigated, and some thermodynamic parameters were calculated. Polarization studies showed that all three studied inhibitors were of mixed type in nature. The adsorption of the inhibitors on the mild steel surface in acid solution was found to obey the Langmuir adsorption isotherm. Scanning ele...

Abstract: Article on the solubility of carvedilol in ethanol and propylene glycol mixtures at various temperatures.

Abstract: Propene oxide is a very important chemical whose production technology has changed a lot during the last 30 years. Nowadays, the most promising technology is the HPPO process in which the propene oxide is produced by oxidizing propene with hydrogen peroxide, via titanium silicalite-1 (TS-1) catalysis. Even if this technology has been patented in the early 1980s and some chemical plants are already in production, only few papers have been published until now dealing with the catalytic and kinetic aspects of the process. In this paper, the state of the art of the scientific knowledge and technical aspects related to propene oxide synthesis in the presence of TS-1 catalyst have been reviewed.

Abstract: For plant-wide process monitoring, most traditional multiblock methods are under the assumption that some process knowledge should be incorporated for dividing the process into several sub-blocks. ...

Abstract: A simple vapor-phase deposition process has been developed to fabricate a superhydrophobic and superoleophilic sponge using ordinary commercial polyurethane sponges. The simultaneous properties of superhydrophobicity and superoleophilicity enable the sponge to float on the water surface and selectively absorb oil from water. Its uptake capacities of different oils (motor oil, lubricating oil, pump oil, silicone oil, and soybean oil) in the oil–water mixtures were all above 20 g/g. The absorbed oil could be collected by squeezing the sponge, and the recovered sponge could be reused in oil–water separation for many cycles while still maintaining a high capacity. This is helpful for realizing the proper disposal of the oil and avoiding secondary pollution. A similar experiment was performed using the as-prepared sponge to remove petroleum from contaminated water. The results suggest that our material might find practical applications in the cleanup of oil spills and the removal of organic pollutants from wat...

Abstract: High density polyethylene (HDPE) cracking has been carried out in a thermal-catalytic two-step unit for the selective production of light olefins. Continuous pyrolysis of HDPE has been conducted in a conical spouted bed reactor at 500 °C, and the volatiles formed (mainly waxes) have been transformed in a downstream fixed bed catalytic reactor at 500 °C. The effect of catalyst acidity on product yield and composition has been studied by using three catalysts based on HZSM-5 zeolites with a SiO2/Al2O3 ratio of 30, 80, and 280. The maximum light olefin yield (58 wt %) has been obtained using the most acidic catalyst (SiO2/Al2O3 ratio of 30), with the individual yields of ethylene, propylene, and butenes being 9.5, 32, and 16.5 wt %, respectively. The results are a clear evidence of the higher efficiency of the two-step reaction system compared to the in situ catalytic pyrolysis (single-step), which is explained by the suitable combination of operating conditions in each one of the steps.

Abstract: Permeation and separation properties of CO2/H2 and CO2/N2 mixtures for high quality, thin (∼14 μm) MOF-5 membranes prepared by the secondary growth method were studied at different temperatures, feed pressures, and feed composition. The MOF-5 membranes offer selective permeation for CO2 over H2 or N2 with CO2/H2 or CO2/N2 mixture feed under the experimental conditions studied. Compared to pure gas permeance data, the presence of the strongly adsorbing CO2 in the binary mixture separation suppresses less adsorbing H2 or N2, similar to what was observed for zeolite membranes. The MOF-5 membranes exhibit a separation factor for CO2/H2 of close to 5 with a feed CO2 composition of 82% and a separation factor for CO2/N2 greater than 60 with a feed CO2 composition of 88% at 445 kPa and 298 K. With the mixture feed, CO2 permeance increases and N2 (or H2) permeance decreases, and hence the CO2/N2 (or H2) separation factor increases, with increasing CO2 partial pressure (through the change of composition or feed pr...

Abstract: Recently, persulfate has caught the attention of groundwater remediation practitioners as a promising oxidant for in situ chemical oxidation. In this study, a method was applied to treat a selection of hazardous organic compounds using nanoscale zerovalent iron (nZVI) particles as activators for persulfate. The results show that degradation of these organic compounds using nZVI-activated persulfate is more effective than nZVI alone. For example, the degradation of naphthalene by nZVI-activated persulfate was >99% compared to <10% by nZVI alone. Despite the higher effectiveness, the nZVI particles were passivated quickly following exposure to persulfate, causing the reaction rate to reduce to a magnitude representative of an unactivated persulfate system. X-ray photoelectron spectroscopy analyses indicated that an iron sulfate layer was formed on the nZVI particle surfaces following exposure to persulfate compared to the FeOOH layer that was present on the fresh nZVI surfaces. Although the nZVI particle su...

Abstract: The methanation of CO and CO2 present in coke oven gas was performed in a fixed-bed catalytic reactor at a reaction temperature between 200 and 400 °C. Different support materials, including SiO2, ...

Abstract: The effects of three metal chlorides including FeCl3, CuCl2, and AlCl3 on corn stover biomass pretreatment and enzymatic hydrolysis were studied under lower severity conditions (reaction temperature of 150–160 °C, salt concentration of 0.075–0.125M, and reaction time of 10 min). The results were compared with dilute sulfuric acid pretreatment at the same conditions. The maximum monomeric xylose yields were observed to be 93 and 94 wt % when CuCl2 and FeCl3 were used in the pretreatment at 160 °C for 10 min at 0.125 M concentrations, which were higher than the sulfuric acid pretreatment yields at the same reaction conditions. However, monomeric xylose yield for corn stover pretreated with AlCl3 was observed to be 8 wt % at the same condition. This could be explained by isomerization of xylose to xylulose and subsequent dehydration into furfural. However, enzymatic digestibility yields for the three metal chloride pretreated samples at 160 °C were greater than 92 wt % . These yields were higher than sulfuri...

Abstract: Well-crystallized layered two-dimensional bismuth oxyhalide (BiOX; X = Cl, Br, I) single-crystal nanoplates were synthesized via a facile and low-cost method at room temperature. The as-synthesized samples were analyzed by various characterization techniques. The photocatalytic activity of the samples was evaluated by the removal of NO at the indoor air level under visible-light irradiation. The band gap and thermal stability of bismuth oxyhalides decreased with increased X atomic numbers. The as-synthesized BiOBr nanoplates exhibited highest photocatalytic activity due to the favorable factors of ultrathin nanoplates, layered structures, relatively high surface area, and suitable band structure, exceeding that of BiOCl and BiOI. The present work could provide new insight into the low-temperature preparation and appropriate selection of visible-light photocatalysts for environmental application.

Abstract: The magnetic chitosan–iron(III) hydrogel (MCh-Fe) was synthesized and characterized by SEM, TG, XRD, and FT-IR and used to remove toxic chromium(VI) (CrVI) from aqueous solution. The adsorption of CrVI onto the MCh-Fe adsorbent was fast and could reach equilibrium in less than 30 min. The adsorption was well described by the pseudo-second-order rate model. The equilibrium isotherm was better matched with the Langmuir model. The adsorption of CrVI onto MCh-Fe was an endothermic and spontaneous process. The loading capacity of CrVI on the adsorbent remained at a high level even after five cycles, showing that MCh-Fe can be used for repeated CrVI removal. Column adsorption results indicated that below 0.5 mg L–1 CrVI was found in the effluent up to about 30 and 350 bed volumes for two wastewaters containing 115.0 and 5.6 mg L–1 CrVI, respectively. The CrVI removal mechanism of MCh-Fe was also investigated.

Abstract: We describe the development and application of an improved, membrane-based, liquid–liquid separator. Membrane-based separation relies on the exploitation of surface forces and the use of a membrane wetted by one of the phases; however, successful separation requires accurate control of pressures, making the operation and implementation cumbersome. Here we present an improved separator design that integrates a pressure control element to ensure that adequate operating conditions are always maintained. Additionally, the integrated pressure control decouples the separator from downstream unit operations. A detailed examination of the controlling physical equations shows how to design the device to allow operation across a wide range of conditions. Easy to implement, multistage separations such as solvent swaps and countercurrent extractions are demonstrated. The presented design significantly simplifies applications ranging from multistep synthesis to complex multistage separations.

Abstract: The crystalline morphologies of electrospun random and aligned poly(e-caprolactone) (PCL) nanofibers, obtained by a plate collector and a two-parallel-conductive-plate collector, respectively, were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), two-dimensional wide-angle X-ray diffraction (2D WAXD), and polarized Fourier transform infrared (polarized FTIR) spectroscopy. The fiber orientations and diameters of the aligned nanofibers were found to depend on the gap size of the collector, which was much larger than those previously reported, thus easing and improving sample handling and characterization. The degree of crystallinity of the aligned nanofibers was higher than that of their randomly aligned counterparts. The crystallites in the nanofibers were highly oriented along the nanofiber axis, as were the molecular chains. The estimated crystallite size suggested that a single nanofiber was composed of dozens of nanofibrils and that each nanofibril was furth...