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supercritical-methanol
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Experimental and Theoretical Study of Biomass Conversion to Green Fuel by Using Supercritical Fluid
, M.Sc. Thesis Sharif University of Technology ; Ghotbi, Cyrus (Supervisor) ; Karimi Sabet, Javad (Supervisor)
Abstract
Nowadays, one of the most basic human problem is how to manage energy resources for sustainable development and how to deal with problems caused by growing energy consumption. Various scenarios are being discussd that the most important of them can be considered research on finding alternative energy sources that are renewable and do not have common pollution. Thus, according to researches carried out until now, using sources such as wind, water, solar biomass, etc. have been proposed. However, due to problems in the development of each of these sources, biomass as the primary option has been introduced. because biomass has several subsidiaries, research shows microalgaes (as a subset) are...
Novel visible light photocatalytic and photoelectrochemical (PEC) activity of carbon-doped zinc oxide/reduced graphene oxide: supercritical methanol synthesis with enhanced photocorrosion suppression
, Article Journal of Alloys and Compounds ; Volume 723 , 2017 , Pages 1001-1010 ; 09258388 (ISSN) ; Soltani, T ; Lee, B. K ; Outokesh, M ; Tayebi, M ; Sharif University of Technology
Abstract
Carbon-doped zinc oxide/reduced graphene oxide (C-ZnO/rGO) was prepared by a facile one-pot supercritical methanol method. The synthesized C-ZnO/rGO nanocomposite with flower-like ZnO micro-rods (MRs) synergistically inherited all the advantages of carbon doping and rGO heterojunction and exhibited high photocatalytic activity for the photodegradation of methyl orange (MO) under visible light. The x-ray diffraction (XRD) results indicated that in presence of GO, a new carbon-doped phase was formed at the high temperature and pressure of supercritical methanol. The x-ray photoelectron spectroscopy (XPS) at low binding energies demonstrated that the valence band of C-ZnO-rGO is up-shifted by...
Fabrication of new magnetite-graphene nanocomposite and comparison of its laser-hyperthermia properties with conventionally prepared magnetite-graphene hybrid
, Article Materials Science and Engineering C ; Volume 75 , 2017 , Pages 572-581 ; 09284931 (ISSN) ; Moradi, S ; Azizi, F ; Outokesh, M ; Shadanfar, K ; Mousavi, S. S ; Sharif University of Technology
Abstract
A single step supercritical method was introduced for synthesis of “magnetite - reduced graphene oxide (M-rGO)” composite in supercritical methanol. Modified surface, smaller size, lesser cytotoxicity, and homogenous dispersion of Fe3O4 nanoparticles on the graphene surface were advantages of this new M-rGO composite in comparison to the materials synthesized by conventional wet chemical method (M-GO). Nanocomposites were injected in tissue equivalent phantoms of agarose gel in 10 mg/g dosage, and were irradiated by a 1600 mW laser beam at wavelength of 800–810 nm. The M-rGO and M-GO were found to be the most and the least efficient samples for increasing the temperature of the phantom. As...
Biodiesel production from Spirulina microalgae feedstock using direct transesterification near supercritical methanol condition
, Article Bioresource Technology ; Volume 239 , 2017 , Pages 378-386 ; 09608524 (ISSN) ; Karimi Sabet, J ; Ghotbi, C ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
Microalgae as a candidate for production of biodiesel, possesses a hard cell wall that prevents intracellular lipids leaving out from the cells. Direct or in situ supercritical transesterification has the potential for destruction of microalgae hard cell wall and conversion of extracted lipids to biodiesel that consequently reduces the total energy consumption. Response surface methodology combined with central composite design was applied to investigate process parameters including: Temperature, Time, Methanol-to-dry algae, Hexane-to-dry algae, and Moisture content. Thirty-two experiments were designed and performed in a batch reactor, and biodiesel efficiency between 0.44% and 99.32% was...