CO2 adsorption of lignite chars after one-step KOH activation

Biomass-derived porous carbons are considered as one of the most promising electrode materials for supercapacitors due to their low-cost and natural abundance. In this work, pinecone is used to fabricate biomass N, S, O-doped porous carbon via one-step carbonization process with KOH activation. By optimizing the additive amount of KOH and calcination temperature, the asprepared product shows a high specific surface area and pore volume up to 1593.8 m2 g−1 and 0.8582 cm3 g−1, respectively. As an electric double-layer capacitor (EDLC) electrode, the N, S, O-doped porous carbon exhibits a high specific capacitance of 285 F g−1 at 0.5 A g−1 and good rate performance with a capacitance retention of 78.6% from 0.5 to 20 A g−1. Furthermore, the as-assembled symmetric supercapacitor with 6 mol L−1 KOH as electrolyte possesses a promising energy density of 6.34 Wh kg−1 and a power density of 250 W kg−1. Outstanding cycling stability was also demonstrated with 94.4% capacitance retention after 10,000 charge/discharge cycles at 1 A g−1.

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Design and Development of a Low Cost Chirp Generator for Airborne Synthetic Aperture Radar

PIERS Online ◽

10.2529/piers080904223354 ◽

2009 ◽

Vol 5 (3) ◽

pp. 269-272

Author(s):

Yee Kit Chan ◽

S. Y. Lim

Keyword(s):

Synthetic Aperture Radar ◽

Low Cost ◽

Synthetic Aperture ◽

Design And Development ◽

Aperture Radar

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Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

10.26434/chemrxiv.12448970.v1 ◽

2020 ◽

Author(s):

Baojian Xiong ◽

Yue Li ◽

Yin Wei ◽

Søren Kramer ◽

Zhong Lian

Keyword(s):

Functional Group ◽

Low Cost ◽

Cross Coupling ◽

Coupling Reactions ◽

Phenol Derivatives ◽

Cross Coupling Reactions ◽

Palladium Catalyzed ◽

One Step ◽

Aryl Tosylates ◽

Low Sensitivity

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.

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Application of Disk Aerators to Recarbonation of Alkaline Wastewater from Wet Gasification of Carbide

Water Science & Technology ◽

10.2166/wst.1991.0211 ◽

1991 ◽

Vol 24 (7) ◽

pp. 277-284 ◽

Cited By ~ 2

Author(s):

E. Gomólka ◽

B. Gomólka

Keyword(s):

Carbon Dioxide ◽

Liquid Phase ◽

Gas Phase ◽

Flue Gas ◽

Carbonic Acid ◽

Low Cost ◽

Flue Gases ◽

Carbon Dioxide Content ◽

Patent Claim ◽

Phase Dispersion

Whenever possible, neutralization of alkaline wastewater should involve low-cost acid. It is conventional to make use of carbonic acid produced via the reaction of carbon dioxide (contained in flue gases) with water according to the following equation: Carbon dioxide content in the flue gas stream varies from 10% to 15%. The flue gas stream may either be passed to the wastewater contained in the recarbonizers, or. enter the scrubbers (which are continually sprayed with wastewater) from the bottom in oountercurrent. The reactors, in which recarbonation occurs, have the ability to expand the contact surface between gaseous and liquid phase. This can be achieved by gas phase dispersion in the liquid phase (bubbling), by liquid phase dispersion in the gas phase (spraying), or by bubbling and spraying, and mixing. These concurrent operations are carried out during motion of the disk aerator (which is a patent claim). The authors describe the functioning of the disk aerator, the composition of the wastewater produced during wet gasification of carbide, the chemistry of recarbonation and decarbonation, and the concept of applying the disk aerator so as to make the wastewater fit for reuse (after suitable neutralization) as feeding water in acetylene generators.

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Surface Modification of Poly(Vinylchloride) for Manufacturing Advanced Catheters

Current Medicinal Chemistry ◽

10.2174/0929867327666200227152150 ◽

2020 ◽

Vol 27 (10) ◽

pp. 1616-1633 ◽

Cited By ~ 2

Author(s):

Oana Cristina Duta ◽

Aurel Mihail Ţîţu ◽

Alexandru Marin ◽

Anton Ficai ◽

Denisa Ficai ◽

...

Keyword(s):

Surface Modification ◽

Chemical Modification ◽

Medical Devices ◽

Low Cost ◽

Physical And Mechanical Properties ◽

Polymeric Materials ◽

Modern Medicine ◽

Structural Failure ◽

Chemical Grafting ◽

One Step

Polymeric materials, due to their excellent physicochemical properties and versatility found applicability in multiples areas, including biomaterials used in tissue regeneration, prosthetics (hip, artificial valves), medical devices, controlled drug delivery systems, etc. Medical devices and their applications are very important in modern medicine and the need to develop new materials with improved properties or to improve the existent materials is increasing every day. Numerous reasearches are activated in this domain in order to obtain materials/surfaces that does not have drawbacks such as structural failure, calcifications, infections or thrombosis. One of the most used material is poly(vinylchloride) (PVC) due to its unique properties, availability and low cost. The most common method used for obtaining tubular devices that meet the requirements of medical use is the surface modification of polymers without changing their physical and mechanical properties, in bulk. PVC is a hydrophobic polymer and therefore many research studies were conducted in order to increase the hydrophilicity of the surface by chemical modification in order to improve biocompatibility, to enhance wettability, reduce friction or to make lubricious or antimicrobial coatings. Surface modification of PVC can be achieved by several strategies, in only one step or, in some cases, in two or more steps by applying several techniques consecutively to obtain the desired modification / performances. The most common processes used for modifying the surface of PVC devices are: plasma treatment, corona discharge, chemical grafting, electric discharge, vapour deposition of metals, flame treatment, direct chemical modification (oxidation, hydrolysis, etc.) or even some physical modification of the roughness of the surface.

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Low-Cost Organic Adsorbents for Elemental Mercury Removal from Lignite Flue Gas

Energies ◽

10.3390/en14082174 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2174

Author(s):

Marta Marczak-Grzesik ◽

Stanisław Budzyń ◽

Barbara Tora ◽

Szymon Szufa ◽

Krzysztof Kogut ◽

...

Keyword(s):

Flue Gas ◽

Low Cost ◽

Elemental Mercury ◽

Mercury Content ◽

Flue Gases ◽

Mercury Removal ◽

Gas Purification ◽

Gas Temperature ◽

Corn Straw ◽

Flue Gas Purification

The research presented by the authors in this paper focused on understanding the behavior of mercury during coal combustion and flue gas purification operations. The goal was to determine the flue gas temperature on the mercury emissions limits for the combustion of lignites in the energy sector. The authors examined the process of sorption of mercury from flue gases using fine-grained organic materials. The main objectives of this study were to recommend a low-cost organic adsorbent such as coke dust (CD), corn straw char (CS-400), brominated corn straw char (CS-400-Br), rubber char (RC-600) or granulated rubber char (GRC-600) to efficiently substitute expensive dust-sized activated carbon. The study covered combustion of lignite from a Polish field. The experiment was conducted at temperatures reflecting conditions inside a flue gas purification installation. One of the tested sorbents—tire-derived rubber char that was obtained by pyrolysis—exhibited good potential for Hg0 into Hg2+ oxidation, resulting in enhanced mercury removal from the flue. The char characterization increased elevated bromine content (mercury oxidizing agent) in comparison to the other selected adsorbents. This paper presents the results of laboratory tests of mercury sorption from the flue gases at temperatures of 95, 125, 155 and 185 °C. The average mercury content in Polish lignite was 465 μg·kg−1. The concentration of mercury in flue gases emitted into the atmosphere was 17.8 µg·m−3. The study analyzed five low-cost sorbents with the average achieved efficiency of mercury removal from 18.3% to 96.1% for lignite combustion depending on the flue gas temperature.

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Design and Development of a Low Cost, Non-Contact Infrared Thermometer with Range Compensation

Sensors ◽

10.3390/s21113817 ◽

2021 ◽

Vol 21 (11) ◽

pp. 3817

Author(s):

Nicholas Wei-Jie Goh ◽

Jun-Jie Poh ◽

Joshua Yi Yeo ◽

Benjamin Jun-Jie Aw ◽

Szu Cheng Lai ◽

...

Keyword(s):

Measurement Accuracy ◽

Low Cost ◽

Common Symptom ◽

Ultrasonic Sensors ◽

Design And Development ◽

Infrared Thermometer ◽

Compensation Methods ◽

Monitoring Devices ◽

Distance Correction

Fever is a common symptom of many infections, e.g., in the ongoing COVID-19 pandemic, keeping monitoring devices such as thermometers in constant demand. Recent technological advancements have made infrared (IR) thermometers the choice for contactless screening of multiple individuals. Yet, even so, the measurement accuracy of such thermometers is affected by many factors including the distance from the volunteers’ forehead, impurities (such as sweat), and the location measured on the volunteers’ forehead. To overcome these factors, we describe the assembly of an Arduino-based digital IR thermometer with distance correction using the MLX90614 IR thermometer and HC-SR04 ultrasonic sensors. Coupled with some analysis of these factors, we also found ways to programme compensation methods for the final assembled digital IR thermometer to provide more accurate readings and measurements.

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