Vapour Phase Synthesis of 2-Methylpyridine and 4-Methylpyridine Over Potassium Salts of 12-Tungstophosphoric Acid

Vapor phase dehydrocyclization reaction of acetaldehyde and ammonia was investigated over K salts of 12-tungstophosphoric acid as catalysts in a continuous flow fixed bed reactor at 350–450℃. The yield of 2-methylpyridine and 4-methylpyridine were found to be in the range of 38.0–64.5%. The 2-methylpyridine and 4-methylpyridine are used for the preparation of insecticides, poultry drugs, cattle drugs and anti-tuberculosis drugs, veterinary analgesics etc. respectively. The reaction conditions such as temperature, contact time, and molar ratio for achieving optimal yield with respect to 2-methylpyridine and 4-methylpyridine were discussed. Catalysts were characterized through BET surface area, FT-IR, XRD and TGA. NH3-TPD studies exhibit the moderate acidity. The morphology of the catalysts was also studied by FESEM

Mercury in Indian Thermal Coals

In India, coal utilization in power generation, constitutes as the single largest source of mercury emissions. This study presents mercury content in Indian sub-bituminous and bituminous coals that are primarily used as fuel in large-scale electricity generation facilities. A total of 165 number of coal samples have been collected from the major coal producing regions of the country. Along with the mercury content, other chemical parameters like moisture, ash, volatile matter, total Sulphur and gross calorific value were also analyzed. Mercury concentrations of these coals were found to be between 3 and 554 µg/kg, with an average of 175 µg/kg. Variation of the mercury content with the rank parameters like volatile matter, carbon content, ash and total Sulphur were also assessed. No significant correlations were observed with the rank parameters but a general trend of increasing mercury with ash content is discernible

Mercury emissions and partitioning from Indian coal-fired power plants

In India coal combustion is the single largest source of emission of mercury which is a wide-spread persistent global toxicant, travelling across international borders through air and water. As a party to the Minamata convention, India aims to monitor and reduce Hg emissions and stricter norms are introduced for mercury emissions from power plants (30 μg/Nm3 for flue gas in stack). This paper presents the results obtained during the experimental studies performed on mercury emissions at four coal-fired and one lignite-fired power plants in India. The mercury concentration in the feed coal varied between 0.12–0.27 mg/Kg. In the mercury mass balance, significant proportion of feed coal mercury has been found to be associated with fly ash, whereas bottom ash contained very low mercury. 80%–90% of mercury was released to air through stack gas. However, for circulating fluidised bed boiler burning lignite, about 64.8% of feed mercury was found to get captured in the fly ash and only 32.4% was released to air. The mercury emission factor was found to lie in the range of 4.7–15.7 mg/GJ. © 2020 Published by Elsevier B.V. on behalf of The Research Centre for Eco-Environmental Sciences, Chinese Academy of Science

Investigation on mercury flow and emission in integrated primary iron production process

The Minamata convention addresses the issue related to mercury poisoning and aim to reduce mercury pollution, as mercury is one of the major concerns for human health. Globally Steel industry is an important source of anthropogenic mercury release. India being one of the largest steel producing country need to look after into details of mercury emission from steel industry. The raw materials like iron ore, coal contains small amount of mercury, which released during steel production. In this study, field studies have been conducted for estimation of mercury input and release from an integrated steel plant in India. Various raw materials, products and wastes are collected for mercury analysis. Mercury mass balances for individual processes were estimated and sinter, coke production processes are found to be significant contributor. Overall mercury mass balance of the plant shows 31.9% of mercury is released through flue gas in various process along with that coke oven gas and Blast furnace gas are also significant contributor. The mercury emission factor for the studied plant found to be 0.057 g Hg/tonne of hot metal production

Vapour Phase Synthesis of 2-Methylpyridine and 4-Methylpyridine Over Potassium Salts of 12-Tungstophosphoric Acid

Vapor phase dehydrocyclization reaction of acetaldehyde and ammonia was investigated over K salts of 12-tungstophosphoric acid as catalysts in a continuous flow fixed bed reactor at 350–450℃. The yield of 2-methylpyridine and 4-methylpyridine were found to be in the range of 38.0–64.5%. The 2-methylpyridine and 4-methylpyridine are used for the preparation of insecticides, poultry drugs, cattle drugs and anti-tuberculosis drugs, veterinary analgesics etc. respectively. The reaction conditions such as temperature, contact time, and molar ratio for achieving optimal yield with respect to 2-methylpyridine and 4-methylpyridine were discussed. Catalysts were characterized through BET surface area, FT-IR,XRD and TGA. NH3-TPD studies exhibit the moderate acidity. The morphology of the catalysts was also studied by FESEM

Vapour Phase Synthesis of 2-Methylpyridine and 4-Methylpyridine Over Potassium Salts of 12-Tungstophosphoric Acid

814-820Vapor phase dehydrocyclization reaction of acetaldehyde and ammonia was investigated over K salts of 12-tungstophosphoric acid as catalysts in a continuous flow fixed bed reactor at 350–450℃. The yield of 2-methylpyridine and 4-methylpyridine were found to be in the range of 38.0–64.5%. The 2-methylpyridine and 4-methylpyridine are used for the preparation of insecticides, poultry drugs, cattle drugs and anti-tuberculosis drugs, veterinary analgesics etc. respectively. The reaction conditions such as temperature, contact time, and molar ratio for achieving optimal yield with respect to 2-methylpyridine and 4-methylpyridine were discussed. Catalysts were characterized through BET surface area, FT-IR, XRD and TGA. NH3-TPD studies exhibit the moderate acidity. The morphology of the catalysts was also studied by FESEM

Mercury in coal from south eastern coalfeld and mercury partitioning at sub‑critical coal‑fred power plant

India is considered as one of the major mercury emitters of the world. Coal combustion in power plants is the foremost source of mercury emissions. Coal samples from South Eastern Coalfeld (SECL) region, India were assessed for mercury content and its partition in a 500 MW boiler unit of a coal-fred power plant. Hg content in the runof mine coal samples varied from 0.011 to 0.188 mg/kg. The Hg content in coal was positively correlated with ash and sulfur. In the power plant, about 65% of the Hg present in the feed coal was emitted through stack, whereas the rest were associated with the fne fy ash (33%), bottom ash (1.9%), and mill rejects (0.1%).The concentration of total Hg in the stack gas varied from 8.5 to 13.7 μg/Nm3, wherein Hg0 (74–81%) was much higher than Hg2+ (19–26%). The estimated mercury emission factor was 1.0–3.2 mg/GJ, which is comparatively higher due to the use of high ash coal and the lack of fue gas desulphurisation system. Hg portion�ing along the fue gas hoppers were also investigated which indicates relationship between Hg adsorption and carbon/sulfur content of the fy ash

Fluorescent carbon nanomaterials from coal and its derivatives: structure, properties, and applications

Coal is a cheap and sustainable precursor for the preparation of fuorescent carbon nanomate�rials (FCNMs). Based on the size and morphology, these nanomaterials are classifed as carbon quan�tum dots (CQDs), carbon nanotubes (CNTs), carbon nanofbers (CNFs), carbon nanosheets (CNSs), graphene quantum dots (GQDs), carbon polymer dots (CPDs) etc. The FCNMs have sparked inter�est because of their distinctive fuorescence, efec�tive catalysis, water solubility, biocompatibility, ease of surface functionalization, cost-efective synthesis, photostability, and other potential benefts for various advanced applications. A substantial percentage of the scientifc community has been driven by a strong desire to prepare carbon nanomaterials (CNMs) using environmentally acceptable and low-cost synthe�sis methods. The precursors used in the preparation of carbon-based nanomaterials are critical to the technology’s future success. Most traditional syn�thesis procedures use high-cost carbon feedstocks like hydrocarbons and graphite, limiting their com�mercialization. In this review, coal is used as starting material for the synthesis of FCNMs and is applied in various current felds.Highlights • Coal and its derivatives derived fuo�rescent carbon nanomaterials are discussed. • Diferent type of methodology basically top-down and bottom-up for the preparation of fuorescent car�bon nanomaterials are described. • The physical and optical properties of fuorescent carbon nanomaterials are discussed. • The origin of fuorescence on coal-based nanomate�rials have been discussed. • The multifunctional applications of fuorescent car�bon nanomaterials are summarized in detail. • The advantage, challenges and future prospects of fuorescent Carbon Nanomaterials from Coal is discusse

A fluorescent probe for bisulfite ions: its application to two-photon tissue imaging

A benzoxazinone based fluorescent probe for the specific and efficient detection of bisulfite ions in aqueous medium is described. The probe formed a bisulfite/sulphite adduct with an associated turn-on fluorescence response in the red wavelength region. No interference was observed in the detection process from all possible competing anions and molecules, including cyanide ion, cysteine, homocysteine and glutathione. In addition, the probe showed a fast response time, low detection limit, and cell membrane permeability. Furthermore, the probe was two-photon excitable, enabling imaging of endogenous bisulfite ions in HeLa cells as well as in deep tissues from different organs of mouse.1182sciescopu