Hasil untuk "Chemical industries"

M. C. Dias, D. Pinto, Artur M. S. Silva

In recent years, more attention has been paid to natural sources of antioxidants. Flavonoids are natural substances synthesized in several parts of plants that exhibit a high antioxidant capacity. They are a large family, presenting several classes based on their basic structure. Flavonoids have the ability to control the accumulation of reactive oxygen species (ROS) via scavenger ROS when they are formed. Therefore, these antioxidant compounds have an important role in plant stress tolerance and a high relevance in human health, mainly due to their anti-inflammatory and antimicrobial properties. In addition, flavonoids have several applications in the food industry as preservatives, pigments, and antioxidants, as well as in other industries such as cosmetics and pharmaceuticals. However, flavonoids application for industrial purposes implies extraction processes with high purity and quality. Several methodologies have been developed aimed at increasing flavonoid extraction yield and being environmentally friendly. This review presents the most abundant natural flavonoids, their structure and chemical characteristics, extraction methods, and biological activity.

Hao Peng, Jing Guo

Luzhao Sun, Guowen Yuan, Libo Gao et al.

Naresh Yadav Donkadokula, Anand Kishore Kola, Iffat Naz et al.

The utilization of dyes in textile industries has enormously increased in recent years and has created several environmental problems. Currently, several methods are in practice to treat wastewaters. Effective and efficient treatment techniques before the discharge of used water in the environment are the need of the hour. This short review covers the research and recent developments in advanced wastewater treatment techniques such as nanophotocatalysis, ceramic nanofiltration membranes, and biofilms. The primary intent of this review article is to contribute the ready-made references for the active researchers and scientists working in the field of wastewater treatment. This review has mainly focused on advanced physico-chemical and biological techniques for the treatment of textile dye wastewaters. Further, the influence of various operating factors on the treatment, advantages, and disadvantages of various techniques was also discussed. The recently developed materials for wastewater treatment are also summarized based on the latest available literature.

Gabriel Lopez, D. Keiner, M. Fasihi et al.

Following current trends, the global chemical industry is set to become the largest consumer of fossil fuels. Among energy intensive industries, the chemical industry is one of the most challenging...

Nei Pereira Junior

Lignocellulosic biomass is one of the most abundant renewable carbon resources available, currently used predominantly for energy generation through direct combustion, yet still underutilized as a feedstock for higher-value biochemical conversion. Its structural complexity and intrinsic recalcitrance continue to challenge efficient biological processing. Overcoming these barriers requires an integrated understanding of plant cell-wall architecture, pretreatment chemistry, enzymatic mechanisms, and process engineering. This review provides a clear and conceptually grounded synthesis of these elements, illustrating how they converge to enable the development of second-generation (2G) lignocellulosic biorefineries. This review examines the hierarchical organization of cellulose, hemicelluloses, and lignin; the principles and performance of modern pretreatment technologies; the synergistic action of cellulolytic systems, including lytic polysaccharide monooxygenases (LPMOs) and non-hydrolytic proteins such as swollenins; advances in C5/C6 sugar fermentation; and emerging strategies for lignin upgrading. In addition to a comprehensive analysis of the literature, representative industrial and experimental case studies reported in the literature are discussed to illustrate practical process behavior and design considerations. By integrating mechanistic insight with industrially relevant examples, this review highlights the technical feasibility, current maturity, and remaining challenges of lignocellulosic biorefineries, underscoring their strategic role in enabling a competitive, low-carbon bioeconomy.

Pankaj Mohindru

The chemical production process is tedious due to the integration of different types of equipment and variables. Designing the controller is crucial in the chemical industry due to the interactive and non-linear system behaviour. An intelligent autonomous controller can improve the operating efficiency of the industry. Although several controllers have been developed, different system failures are frequently reported. Hence, controllers such as proportional integral derivative (PID), fuzzy logic controller (FLC), and hybrid fuzzy PID (F-PID) applied in the chemical industries are critically reviewed in the paper. Initially, the PID controller-based approaches are reviewed for different purposes in the chemical industry. After that, the FLC-based controllers-based papers are reviewed. In order to satisfy the issues in both controllers, the H-PID controllers have been reviewed. This review paper will provide an effective solution for operation control in the chemical industry under different operating conditions.

Sarah K. Mann, Angus Cowley-Semple, Emma Bryan et al.

Optical detection of magnetic resonance enables spin-based quantum sensing with high spatial resolution and sensitivity-even at room temperature-as exemplified by solid-state defects. Molecular systems provide a complementary, chemically tunable, platform for room-temperature optically detected magnetic resonance (ODMR)-based quantum sensing. A critical parameter governing sensing sensitivity is the optical contrast-i.e., the difference in emission between two spin states. In state-of-the-art solid-state defects such as the nitrogen-vacancy center in diamond, this contrast is approximately 30%. Here, capitalizing on chemical tunability, we show that room-temperature ODMR contrasts of 40% can be achieved in molecules. Using a nitrogen-substituted analogue of pentacene (6,13-diazapentacene), we enhance contrast compared to pentacene and, by determining the triplet kinetics through time-dependent pulsed ODMR, show how this arises from accelerated anisotropic intersystem crossing. Furthermore, we translate high-contrast room-temperature pulsed ODMR to self-assembled nanocrystals. Overall, our findings highlight the synthetic handles available to optically readable molecular spins and the opportunities to capitalize on chemical tunability for room-temperature quantum sensing.

Stanica Nedović, Ana Alil, Sanja Martinović et al.

Specific environmental conditions, such as marine environments, often influence steel applications in marine industries. These conditions are commonly simulated using a NaCl solution to simplify the study and eliminate the complexities of seawater's chemical and biological variability. In this study, 42CrMo4 steel samples, a widely utilized material in components subjected to static and dynamic stresses found in vehicles, engines, and machinery, were selected for analysis due to their susceptibility to various forms of corrosion. The corrosion behavior of the samples was monitored using mass loss and corrosion rate. The results were then correlated with changes in mechanical properties, including tensile strength and Brinell hardness. The study provides insight into how corrosion impacts the degradation of mechanical properties.

Kushagra Singh, Souradeep Gupta

The application of carbon-rich char-based admixtures, including biochar and plastic char, in construction products has received substantial attention from global industries due to their potential to “lock in” carbon for the long term, thus mitigating the climatic impacts of future constructions. Furthermore, a sharp rise in plastic waste generation and uncontrolled landfilling threatens natural ecosystems. Depending on type, plastic waste can be used as fuel, and the generated char (solid residue) can be reintegrated into the construction value chain by utilizing it as a carbon-sequestering admixture in construction materials. This article discusses critical factors, including the synthesis temperature, heating rate, and different activation pathways, for tuning plastic char’s porosity and surface properties, contributing to enhanced carbon fixation and CO2 uptake. Chemical pyrolysis using alkaline agents produces microporous structure (< 2 nm) with high surface areas (> 1000 m2g−1) and CO2 uptake, ranging up to 4.6 mmolg−1 while acidic agents produce a higher fraction of mesopores (> 2 nm) with lower surface areas < 1500 m2g−1 and CO2 uptake capacities (up to 1.8 mmolg−1). The review finds that surface functionalization of plastic char and altering its physicochemical properties improve the engineering properties of construction binders. The locked carbon in the char, complemented by additional CO2 uptake in the engineered pore and surface sites, can be instrumental in mitigating the embodied carbon of construction products. However, future investigations should study the microstructural interactions of engineered char within construction binders and conduct a holistic life-cycle assessment to fully realize the benefits of using engineered plastic char as a supplementary additive.

Chao Chen, G. Reniers, N. Khakzad

Abstract Recent catastrophic accidents in China and the USA urge and justify a thorough study on current & future research trends in the development of modeling methods and protection strategies for prevention and mitigation of large-scale escalating events or so-called domino effects in the process and chemical industries. This paper firstly provides an overview of what constitutes domino effects based on the definition and features, characterizing domino effect studies according to different research issues and approaches. The modeling approaches are grouped into three types while the protection strategies are divided into five categories, followed by detailed descriptions of representative modeling approaches and management strategies in chemical plants and clusters. The current research trends in this field are obtained based on the analysis of research work on domino effects caused by accidental events, natural events, and intentional attacks over a period of the past 30 years. A comparison analysis is conducted for the current modeling approaches and management strategies to pose their applications. Finally, this paper offers future research directions and identifies critical challenges in the field, aiming at improving the safety and security of chemical industrial areas so as to prevent and mitigate domino effects.

Lucas R. Timmerman, Shashikant Kumar, Phanish Suryanarayana et al.

We develop a framework for on-the-fly machine learned force field molecular dynamics simulations based on the multipole featurization scheme that overcomes the bottleneck with the number of chemical elements. Considering bulk systems with up to 6 elements, we demonstrate that the number of density functional theory calls remains approximately independent of the number of chemical elements, in contrast to the increase in the smooth overlap of atomic positions scheme.

Zihao Wang, Zhe Wu

Developing accurate models for chemical reactors is often challenging due to the complexity of reaction kinetics and process dynamics. Traditional approaches require retraining models for each new system, limiting generalizability and efficiency. In this work, we take a step toward foundation models for chemical reactor modeling by introducing a neural network framework that generalizes across diverse reactor types and rapidly adapts to new chemical processes. Our approach leverages meta-learning to pretrain the model on a broad set of reactor dynamics, enabling efficient adaptation to unseen reactions with minimal data. To further enhance generalizability, we incorporate physics-informed fine-tuning, ensuring physically consistent adaptation to new reactor conditions. Our framework is evaluated across three integer-order fundamental reactor types - continuous stirred tank reactors, batch reactors, and plug flow reactors - demonstrating superior few-shot adaptation compared to conventional data-driven, physics-informed, and transfer learning approaches. By combining meta-learning with physics-informed adaptation, this work lays the foundation for a generalizable modeling framework, advancing the development of foundation models for chemical engineering applications. Source code is available at https://github.com/killingbear999/chemical-reactor-foundation-model.

Imran Nasim, Joaõ Lucas de Sousa Almeida

Scientific Machine Learning is transforming traditional engineering industries by enhancing the efficiency of existing technologies and accelerating innovation, particularly in modeling chemical reactions. Despite recent advancements, the issue of solving stiff chemically reacting problems within computational fluid dynamics remains a significant issue. In this study we propose a novel approach utilizing a multi-layer-perceptron mixer architecture (MLP-Mixer) to model the time-series of stiff chemical kinetics. We evaluate this method using the ROBER system, a benchmark model in chemical kinetics, to compare its performance with traditional numerical techniques. This study provides insight into the industrial utility of the recently developed MLP-Mixer architecture to model chemical kinetics and provides motivation for such neural architecture to be used as a base for time-series foundation models.

Matteo Iaiani, Alessandro Tugnoli, Valerio Cozzani

The increasing interconnectivity with external networks and the higher reliance on digital systems make chemical and process industries, including waste and drinking water treatment plants, more vulnerable to cyber-attacks. Historical evidence shows that these attacks have the potential to cause events with severe consequences on property, people, and the surrounding environment, posing a serious threat. While the risks deriving from the malicious manipulation of the Basic Process Control System (BPCS) and the Safety Instrumented System (SIS) in chemical and Oil&Gas facilities have been systematically analysed in the available literature, including previous works of the Authors, the analysis of the consequences of cyber-attacks to drinking water treatment plants has not been conducted to date. To fill this gap, in the present study the methodology POROS 2.0 (Process Operability Analysis of Remote manipulations through the cOntrol System) developed by the Authors was applied to a drinking water treatment plant, providing valuable insights on possible critical scenarios originated by cyber-attacks in these facilities.

Luma Sarai de Oliveira, Andres David Cordon Cardona, Pedro Henrique Freitas Cardines et al.

In this study, the aim was to modify the starches of three different sweet potato varieties—Rosada Uruguaiana (RU), Rosada Canadense (RC), and Ligeirinha (L)—through in situ annealing to increase the content of slowly digestible starch (SDS), which has health benefits. The modified carbohydrate was then added to a dairy beverage fermented by <i>Lactobacillus casei</i> 1e (<i>L. casei</i>). After annealing, the starches had different physicochemical properties, and the L variety, which had the highest SDS content, was chosen for the formulation of the fermented dairy beverage. Two concentrations of modified starch (7% and 10.5%) were used in the formulations, and a sensory analysis indicated no differences in acceptance and purchase intention. The beverage containing 10.5% modified starch exhibited good physicochemical and microbiological stability. This study demonstrates the possibility of creating a functional fermented dairy beverage with high SDS content, which could potentially benefit consumers’ health.

Emmanuel A. Aboagye, John D. Chea, K. Yenkie

Summary Recovering waste solvent for reuse presents an excellent alternative to improving the greenness of industrial processes. Implementing solvent recovery practices in the chemical industry is necessary, given the increasing focus on sustainability to promote a circular economy. However, the systematic design of recovery processes is a daunting task due to the complexities associated with waste stream composition, techno-economic analysis, and environmental assessment. Furthermore, the challenges to satisfy the desired product specifications, particularly in pharmaceuticals and specialty chemical industries, may also deter solvent recovery and reuse practices. To this end, this review presents a systems-level approach including various methodologies that can be implemented to design and evaluate efficient solvent recovery pathways.

Meng Tang, Shiwei Ma, Jianzheng Xu et al.

Chemical looping gasification (CLG) of biomass produces high contents of syngas, which would have inhibition effect on the gasification of its biomass char. Experiments using a rice husk char as fuel and a low-cost red mud as oxygen carrier for CLG investigation were performed, and effects of temperature, concentrations of steam and H2 on gasification rate were evaluated. Meanwhile, the mathematical models coupling with reaction and diffusion were established focusing on the H2 inhibition on syngas distributions inside and surrounding a single char particle. The results indicated that H2 in the reaction atmosphere has an inhibition effect on its char conversion, and at a high temperature the inhibition effect tends to be stronger. The shrinking core model (spherical symmetry) was found to be suitable to describe the char conversion under the present conditions with the reaction kinetic parameters of E = 128.8 kJ mol−1 and A = 451.2 s−1. In the internal diffusion of a single char particle, the concentrations of CO and H2 both decrease with the increase of dimensionless radius due to the consumption of carbon. In the external diffusion of the char particle, the concentrations of CO and H2 decrease with the increase of the dimensionless radius. The accumulation of H2 inside the char particle prevents CO production, thus inhibiting char gasification.

Zhilin Tian, Keyu Ming, Liya Zheng et al.

Rare earth (RE) silicate is one of the most promising environmental barrier coatings for silicon-based ceramics in gas turbine engines. However, calcium–magnesium–alumina–silicate (CMAS) corrosion becomes much more serious and is the critical challenge for RE silicate with the increasing operating temperature. Therefore, it is quite urgent to clarify the mechanism of high-temperature CMAS-induced degradation of RE silicate at relatively high temperatures. Herein, the interaction between RE2SiO5 and CMAS up to 1500 ℃ was investigated by a novel high-temperature in-situ observation method. High temperature promotes the growth of the main reaction product (Ca2RE8(SiO4)6O2) fast along the [001] direction, and the precipitation of short and horizontally distributed Ca2RE8(SiO4)6O2 grains was accelerated during the cooling process. The increased temperature increases the solubility of RE elements, decreases the viscosity of CMAS, and thus elevates the corrosion reaction rate, making RE2SiO5 fast interaction with CMAS and less affected by RE element species.

Shruthi Dasappa, Joaquin Camacho

The work examines the unique nanostructure of carbon nanoparticles deposited from sooting premixed flames with flame temperatures exceeding 2200 K. This flame temperature regime has previously been shown to transition from typical soot formation conditions to a regime whereby the flame-form carbon adopts a nanostructure considerably more ordered than soot. Graphenic carbon deposits observed by High-resolution TEM (HRTEM) are reported here corroborating previous Raman spectroscopy evidence. The use of premixed stretch-stabilized flames enables particle production in the high-temperature regime under a flow field amenable to low-dimensional flame modeling. Although the flame flow configuration is relatively simple, three sample preparation methods are used to assess the representation of true carbon properties as they exist in the flame. HRTEM imaging is carried out on carbon particle samples prepared by rapid-insertion deposition, aerosol dilution probe deposition and carbon particle film deposition. Images from rapid-insertion samples show amorphous particles in the lightly sooting flame and turbostratic particles in the heavy sooting flame. There is trace evidence of graphenic structure in rapid-insertion samples but the most striking particles on the TEM grid are graphite nanocrystals presumably formed by a new artificial crystallization process. HRTEM images of particles collected over time by diluted aerosol deposition and film deposition show clear graphenic structures. Overall, the carbon nanostructure observed by HRTEM is a mixture of amorphous, turbostratic and graphenic carbon lattices depending on the flame condition and sampling method. The current work highlights potential impacts of higher flame temperatures and higher equivalence ratio on deposited flame-formed carbon. Namely, graphenic particle structure is observed in rapid-insertion deposition samples but graphene portions are most abundant in aerosol dilution and carbon particle film deposition samples. This may indicate that graphene structures grow on the deposition surface over time.