S. Murugavelh

Bio: S. Murugavelh is an academic researcher from VIT University. The author has contributed to research in topics: Desalination & Pyrolysis. The author has an hindex of 12, co-authored 34 publications receiving 388 citations. Previous affiliations of S. Murugavelh include Indian Institute of Technology Guwahati.

A review on solar photovoltaic thermal integrated desalination technologies

Abstract: Desalination processes consume large amount of electricity and heat derived from fossil fuels to produce fresh water. In recent years, solar desalination emerged as a favorable method for sustainable fresh water production with less environmental impacts. A solar photovoltaic thermal collector is a combined system of solar photovoltaic and solar thermal collector that simultaneously generates electricity and thermal energy. The present work reviews photovoltaic thermal collector integrating desalination technologies such as solar still, humidification dehumidification, multiple effect distillation, reverse osmosis, multiple stage flash and membrane distillation. The primary focus is made on successful utilization of electricity and heat from the photovoltaic thermal collector in desalination systems to reduce cost, primary energy consumption and to improve overall system performance. Future opportunities and novel methods to improve/explore the photovoltaic thermal driven desalination systems are reported. Possibilities of photovoltaic thermal collector as energy source for other desalination technologies (electrodialysis, forward osmosis, vapor compression, adsorption desalination and etc.) are also presented. Comparative analysis shows that overall performance of photovoltaic thermal coupled desalination systems is better than desalination systems coupled with separate photovoltaic panel and/or solar thermal collector to meet the energy needs. The additional electricity generated from photovoltaic thermal desalination paves way for standalone desalination in remote location even though the initial costs are a tad higher.

Biodiesel production from waste cotton seed oil using low cost catalyst: Engine performance and emission characteristics

Abstract: Summary Production of fatty acid methyl esters from waste cotton seed oil through transesterification was reported. The GC–MS analysis of WCCO oil was studied and the major fatty acids were found to be palmitic acid (27.76%) and linoleic acid (42.84%). The molecular weight of the oil was 881.039 g/mol. A maximum yield of 92% biodiesel was reported when the reaction temperature, time, methanol/oil ratio and catalyst loading rate were 60 °C, 50 min, 12:1 and 3% (wt.%), respectively. The calcined egg shell catalyst was prepared and characterized. Partial purification of the fatty acid methyl esters was proposed for increasing the purity of the biodiesel and better engine performance. The flash point and the fire point of the biodiesel were found to be 128 °C and 136 °C, respectively. The Brake thermal efficiency of WCCO B10 biodiesel was 26.04% for maximum load, specific fuel consumption for diesel was 0.32 kg/kW h at maximum load. The use of biodiesel blends showed a reduction of carbon monoxide and hydrocarbon emissions and a marginal increase in nitrogen oxides (NO x ) emissions improved emission characteristics.

Patent landscape review on biodiesel production: Technology updates

Abstract: Biodiesel is a renewable fuel made from vegetable oils and animal fats. Compared with fossil fuels, it has the potential to alleviate environmental pressures and achieve sustainable development. In this paper, 1660 patents related to biodiesel production were reviewed. They were published between January 1999 and July 2018 and were retrieved from the Derwent Innovation patent database. The patents were grouped into five categories depending on whether they related to starting materials, pre-treatment methods, catalysts, reactors and processing methods, or testing methods. Their analysis shows that the availability of biodiesel starting materials depends on climate, geographical location, local soil conditions, and local agricultural practices. Starting materials constitute 75% of overall production costs and, therefore, it is crucial to select the best feedstock. Pre-treatment of feedstock can improve its suitability for processing and increase extraction effectiveness and oil yield. Catalysts can enhance the solubility of alcohol, leading to higher reaction rates, faster biodiesel production processes, and lower biodiesel production costs. Moreover, the apparatus and processes used strongly affect the oil yield and quality, and production cost. In order to be commercialized and marketed, biodiesel should pass either the American Society for Testing and Materials (ASTM) standards or European Standards (EN). Due to increases in environmental awareness, it is likely that the number of published patents on biodiesel production will remain stable or even increase.

Mechanisms of Hexavalent Chromium Resistance and Removal by Microorganisms

Abstract: Chromium is a naturally occurring element found in rocks, animals, plants, soil and in volcanic dust and gases. It exists in different oxidation states that range from +2 to +6. The most stable forms are Cr(VI) and Cr(III), although they significantly differ in biological, geochemical and toxicological properties. Cr(III) occurs naturally in the environment at a narrow concentration range and is considered to be less toxic than Cr(VI). Hexavalent chromium is used extensively in industrial processes such as electroplating, tanning, textile dyeing, corrosion inhibition and wood treatment, all of which produce discharge of chromium-containing effluents (Lauwerys et al. 2007). The high solubility of Cr(VI) makes it a hazardous contaminant of water and soil when discharged by industries that produce or utilize chromium. When it is released to the environment, Cr(VI) is a potential contaminant of groundwater that can participate in trophic transfer in food chains. The United States Environmental Protection Agency has identified Cr(VI) as one of the 17 chemicals posing the greatest threat to humans (Marsh and McInerney 2001). The permissible limit for total chromium in drinking water is 0.05 mg/L (WHO 2004).