Hasil untuk "Chemical technology"

J. Artz, T. E. Müller, Katharina Thenert et al.

Hongli Zhu, W. Luo, Peter N. Ciesielski et al.

S. H. Mood, Amir Hossein Golfeshan, M. Tabatabaei et al.

G. Patti, Ó. Yanes, G. Siuzdak

B. Logan, K. Rabaey

Nesrine Jaziri, A. Boughamoura, J. Müller et al.

Abstract Power costs increasing, environmental pollution and global warming are issues that we are dealing with in the present time. To reduce their effects, scientists are focusing on improving energy harvesting-based power generators. Thermoelectric generators (TEGs) have demonstrated their ability to directly convert thermal energy into an electrical one via the Seebeck effect. Also, they are environmentally friendly because they do not contain chemical products, they operate silently because they do not have mechanical structures and/or moving parts, and they can be fabricated on many types of substrates like silicon, polymers, and ceramics. Furthermore, TEGs are position-independent, present a long operating lifetime and are suitable for integration into bulk and flexible devices. This paper presents in-depth analysis of TEGs, starting by an extensive description of their working principle, types (planar, vertical and mixed), used materials, figure of merit, improvement techniques including different thermoelectric materials arrangement (conventional, segmented and cascaded), and used technologies and substrates types (silicon, ceramics and polymers). This manuscript also describes the exploitation of TEGs in various fields starting from low-power applications (medical and wearable devices, IoT: internet of things, and WSN: wireless sensor network) to high-power applications (industrial electronics, automotive engines, and aerospace).

F. Cherubini

D. D’Alessandro, B. Smit, J. Long

S. Al-Salem, P. Lettieri, J. Baeyens

Ellen M. Sletten, C. Bertozzi

E. Aprá, E. Bylaska, W. D. Jong et al.

Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support and guide experimental efforts and for the prediction of atomistic and electronic properties. In this regard, electronic structure packages have played a special role by using first-principle-driven methodologies to model complex chemical and materials processes. Over the past few decades, the rapid development of computing technologies and the tremendous increase in computational power have offered a unique chance to study complex transformations using sophisticated and predictive many-body techniques that describe correlated behavior of electrons in molecular and condensed phase systems at different levels of theory. In enabling these simulations, novel parallel algorithms have been able to take advantage of computational resources to address the polynomial scaling of electronic structure methods. In this paper, we briefly review the NWChem computational chemistry suite, including its history, design principles, parallel tools, current capabilities, outreach, and outlook.

Saranya Kuppusamy, P. Thavamani, Kadiyala Venkateswarlu et al.

For more than a decade, the primary focus of environmental experts has been to adopt risk-based management approaches to cleanup PAH polluted sites that pose potentially destructive ecological consequences. This focus had led to the development of several physical, chemical, thermal and biological technologies that are widely implementable. Established remedial options available for treating PAH contaminated soils are incineration, thermal conduction, solvent extraction/soil washing, chemical oxidation, bioaugmentation, biostimulation, phytoremediation, composting/biopiles and bioreactors. Integrating physico-chemical and biological technologies is also widely practiced for better cleanup of PAH contaminated soils. Electrokinetic remediation, vermiremediation and biocatalyst assisted remediation are still at the development stage. Though several treatment methods to remediate PAH polluted soils currently exist, a comprehensive overview of all the available remediation technologies to date is necessary so that the right technology for field-level success is chosen. The objective of this review is to provide a critical overview in this respect, focusing only on the treatment options available for field soils and ignoring the spiked ones. The authors also propose the development of novel multifunctional green and sustainable systems like mixed cell culture system, biosurfactant flushing, transgenic approaches and nanoremediation in order to overcome the existing soil- contaminant- and microbial-associated technological limitations in tackling high molecular weight PAHs. The ultimate objective is to ensure the successful remediation of long-term PAH contaminated soils.

E. Koytsoumpa, C. Bergins, E. Kakaras

S. Güneş, H. Neugebauer, N. S. Sariçiftçi

A. Tursi

Biomass is currently the most widespread form of renewable energy and its exploitation is further increasing due to the concerns over the devastative impacts of fossil fuel consumption, i.e., climate change, global warming and their negative impacts on human health. In line with that, the present articles reviews the different sources of biomass available, along with their chemical composition and properties. Subsequently, different conversion technologies (i.e., thermo-chemical, biochemical, and physico-chemical conversions) and their corresponding products are reviewed and discussed. In the continuation, the global status of biomass vs. the other renewable energies is scrutinized. Moreover, biomass-derived energy production was analyzed from economic and environmental perspectives. Finally, the challenges faced to further expand the share of biomass-derived energy carriers in the global energy market are presented.

N. McQueen, Katherine Vaz Gomes, Colin McCormick et al.

Direct air capture (DAC) can provide an impactful, engineered approach to combat climate change by removing carbon dioxide (CO2) from the air. However, to meet climate goals, DAC needs to be scaled at a rapid rate. Current DAC approaches use engineered contactors filled with chemicals to repeatedly capture CO2 from the air and release high purity CO2 that can be stored or otherwise used. This review article focuses on two distinctive, commercial DAC processes to bind with CO2: solid sorbents and liquid solvents. We discuss the properties of solvents and sorbents, including mass transfer, heat transfer and chemical kinetics, as well as how these properties influence the design and cost of the DAC process. Further, we provide a novel overview of the considerations for deploying these DAC technologies, including concepts for learning-by-doing that may drive down costs and material requirements for scaling up DAC technologies.

R. Schwarzenbach, B. Escher, K. Fenner et al.

Xuanyong Liu, P. Chu, C. Ding

Mengyue Gong, A. Bassi

Shirong GE, Jing GUO

Deep coal resources with abundant reserves and considerable thermal potential are receiving increased attention in mining engineering, given the accelerating transformation of the global energy structure and the growing demand for clean energy. To address extraction challenges and environmental pressures while ensuring economic feasibility and sustainable development, efforts are made to enable carbon reduction and green transformation under high-efficiency utilization of deep coal resources. A systematic review of “deep coal resource fluidized mining”, “coal chemical mining”, and “coal-based power” informs the introduction of a detonation-generation mining approach and its technical framework. The approach places coal-powder detonation combustion technology at its core and integrates advanced detonation combustion-mechanical/magnetohydrodynamic power generation, forming a detonation-turbine/MHD hybrid power system that supports efficient conversion and clean utilization of coal resources. Four fundamental theories are presented, including the Coal-powder Detonation Energy Release mechanism, the Coupled Coal-powder Detonation-generation Power Scheme, a Full Life Cycle Detonation-power Generation Dynamic Management Mechanism, and the Blasting-electric Power Deep coal mining theory and method. Discussion centers on four key technologies: Stable coal/gas two-phase detonation, detonation model construction and dynamic process optimization, detonation-based power generation efficiency assessment, and comprehensive design for detonation-based coal mining, demonstrating their role in upgrading deep coal mining practices. On this foundation, a systematic engineering strategy is proposed to clarify the synergy between mining processes and the detonation-based power generation mode, highlight safety management and process optimization priorities at each critical stage, and refine the overall detonation-generation pathway for deep coal resource development. This pathway offers valuable insights for establishing a coal-based power system and promoting the clean and efficient utilization of deep coal resources in China.